gold/testsuite: Fix bad regexp in split_x86_64.sh
[external/binutils.git] / gold / arm.cc
1 // arm.cc -- arm target support for gold.
2
3 // Copyright (C) 2009-2018 Free Software Foundation, Inc.
4 // Written by Doug Kwan <dougkwan@google.com> based on the i386 code
5 // by Ian Lance Taylor <iant@google.com>.
6 // This file also contains borrowed and adapted code from
7 // bfd/elf32-arm.c.
8
9 // This file is part of gold.
10
11 // This program is free software; you can redistribute it and/or modify
12 // it under the terms of the GNU General Public License as published by
13 // the Free Software Foundation; either version 3 of the License, or
14 // (at your option) any later version.
15
16 // This program is distributed in the hope that it will be useful,
17 // but WITHOUT ANY WARRANTY; without even the implied warranty of
18 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 // GNU General Public License for more details.
20
21 // You should have received a copy of the GNU General Public License
22 // along with this program; if not, write to the Free Software
23 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
24 // MA 02110-1301, USA.
25
26 #include "gold.h"
27
28 #include <cstring>
29 #include <limits>
30 #include <cstdio>
31 #include <string>
32 #include <algorithm>
33 #include <map>
34 #include <utility>
35 #include <set>
36
37 #include "elfcpp.h"
38 #include "parameters.h"
39 #include "reloc.h"
40 #include "arm.h"
41 #include "object.h"
42 #include "symtab.h"
43 #include "layout.h"
44 #include "output.h"
45 #include "copy-relocs.h"
46 #include "target.h"
47 #include "target-reloc.h"
48 #include "target-select.h"
49 #include "tls.h"
50 #include "defstd.h"
51 #include "gc.h"
52 #include "attributes.h"
53 #include "arm-reloc-property.h"
54 #include "nacl.h"
55
56 namespace
57 {
58
59 using namespace gold;
60
61 template<bool big_endian>
62 class Output_data_plt_arm;
63
64 template<bool big_endian>
65 class Output_data_plt_arm_short;
66
67 template<bool big_endian>
68 class Output_data_plt_arm_long;
69
70 template<bool big_endian>
71 class Stub_table;
72
73 template<bool big_endian>
74 class Arm_input_section;
75
76 class Arm_exidx_cantunwind;
77
78 class Arm_exidx_merged_section;
79
80 class Arm_exidx_fixup;
81
82 template<bool big_endian>
83 class Arm_output_section;
84
85 class Arm_exidx_input_section;
86
87 template<bool big_endian>
88 class Arm_relobj;
89
90 template<bool big_endian>
91 class Arm_relocate_functions;
92
93 template<bool big_endian>
94 class Arm_output_data_got;
95
96 template<bool big_endian>
97 class Target_arm;
98
99 // For convenience.
100 typedef elfcpp::Elf_types<32>::Elf_Addr Arm_address;
101
102 // Maximum branch offsets for ARM, THUMB and THUMB2.
103 const int32_t ARM_MAX_FWD_BRANCH_OFFSET = ((((1 << 23) - 1) << 2) + 8);
104 const int32_t ARM_MAX_BWD_BRANCH_OFFSET = ((-((1 << 23) << 2)) + 8);
105 const int32_t THM_MAX_FWD_BRANCH_OFFSET = ((1 << 22) -2 + 4);
106 const int32_t THM_MAX_BWD_BRANCH_OFFSET = (-(1 << 22) + 4);
107 const int32_t THM2_MAX_FWD_BRANCH_OFFSET = (((1 << 24) - 2) + 4);
108 const int32_t THM2_MAX_BWD_BRANCH_OFFSET = (-(1 << 24) + 4);
109
110 // Thread Control Block size.
111 const size_t ARM_TCB_SIZE = 8;
112
113 // The arm target class.
114 //
115 // This is a very simple port of gold for ARM-EABI.  It is intended for
116 // supporting Android only for the time being.
117 //
118 // TODOs:
119 // - Implement all static relocation types documented in arm-reloc.def.
120 // - Make PLTs more flexible for different architecture features like
121 //   Thumb-2 and BE8.
122 // There are probably a lot more.
123
124 // Ideally we would like to avoid using global variables but this is used
125 // very in many places and sometimes in loops.  If we use a function
126 // returning a static instance of Arm_reloc_property_table, it will be very
127 // slow in an threaded environment since the static instance needs to be
128 // locked.  The pointer is below initialized in the
129 // Target::do_select_as_default_target() hook so that we do not spend time
130 // building the table if we are not linking ARM objects.
131 //
132 // An alternative is to process the information in arm-reloc.def in
133 // compilation time and generate a representation of it in PODs only.  That
134 // way we can avoid initialization when the linker starts.
135
136 Arm_reloc_property_table* arm_reloc_property_table = NULL;
137
138 // Instruction template class.  This class is similar to the insn_sequence
139 // struct in bfd/elf32-arm.c.
140
141 class Insn_template
142 {
143  public:
144   // Types of instruction templates.
145   enum Type
146     {
147       THUMB16_TYPE = 1,
148       // THUMB16_SPECIAL_TYPE is used by sub-classes of Stub for instruction
149       // templates with class-specific semantics.  Currently this is used
150       // only by the Cortex_a8_stub class for handling condition codes in
151       // conditional branches.
152       THUMB16_SPECIAL_TYPE,
153       THUMB32_TYPE,
154       ARM_TYPE,
155       DATA_TYPE
156     };
157
158   // Factory methods to create instruction templates in different formats.
159
160   static const Insn_template
161   thumb16_insn(uint32_t data)
162   { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 0); }
163
164   // A Thumb conditional branch, in which the proper condition is inserted
165   // when we build the stub.
166   static const Insn_template
167   thumb16_bcond_insn(uint32_t data)
168   { return Insn_template(data, THUMB16_SPECIAL_TYPE, elfcpp::R_ARM_NONE, 1); }
169
170   static const Insn_template
171   thumb32_insn(uint32_t data)
172   { return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_NONE, 0); }
173
174   static const Insn_template
175   thumb32_b_insn(uint32_t data, int reloc_addend)
176   {
177     return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_THM_JUMP24,
178                          reloc_addend);
179   }
180
181   static const Insn_template
182   arm_insn(uint32_t data)
183   { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_NONE, 0); }
184
185   static const Insn_template
186   arm_rel_insn(unsigned data, int reloc_addend)
187   { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_JUMP24, reloc_addend); }
188
189   static const Insn_template
190   data_word(unsigned data, unsigned int r_type, int reloc_addend)
191   { return Insn_template(data, DATA_TYPE, r_type, reloc_addend); }
192
193   // Accessors.  This class is used for read-only objects so no modifiers
194   // are provided.
195
196   uint32_t
197   data() const
198   { return this->data_; }
199
200   // Return the instruction sequence type of this.
201   Type
202   type() const
203   { return this->type_; }
204
205   // Return the ARM relocation type of this.
206   unsigned int
207   r_type() const
208   { return this->r_type_; }
209
210   int32_t
211   reloc_addend() const
212   { return this->reloc_addend_; }
213
214   // Return size of instruction template in bytes.
215   size_t
216   size() const;
217
218   // Return byte-alignment of instruction template.
219   unsigned
220   alignment() const;
221
222  private:
223   // We make the constructor private to ensure that only the factory
224   // methods are used.
225   inline
226   Insn_template(unsigned data, Type type, unsigned int r_type, int reloc_addend)
227     : data_(data), type_(type), r_type_(r_type), reloc_addend_(reloc_addend)
228   { }
229
230   // Instruction specific data.  This is used to store information like
231   // some of the instruction bits.
232   uint32_t data_;
233   // Instruction template type.
234   Type type_;
235   // Relocation type if there is a relocation or R_ARM_NONE otherwise.
236   unsigned int r_type_;
237   // Relocation addend.
238   int32_t reloc_addend_;
239 };
240
241 // Macro for generating code to stub types. One entry per long/short
242 // branch stub
243
244 #define DEF_STUBS \
245   DEF_STUB(long_branch_any_any) \
246   DEF_STUB(long_branch_v4t_arm_thumb) \
247   DEF_STUB(long_branch_thumb_only) \
248   DEF_STUB(long_branch_v4t_thumb_thumb) \
249   DEF_STUB(long_branch_v4t_thumb_arm) \
250   DEF_STUB(short_branch_v4t_thumb_arm) \
251   DEF_STUB(long_branch_any_arm_pic) \
252   DEF_STUB(long_branch_any_thumb_pic) \
253   DEF_STUB(long_branch_v4t_thumb_thumb_pic) \
254   DEF_STUB(long_branch_v4t_arm_thumb_pic) \
255   DEF_STUB(long_branch_v4t_thumb_arm_pic) \
256   DEF_STUB(long_branch_thumb_only_pic) \
257   DEF_STUB(a8_veneer_b_cond) \
258   DEF_STUB(a8_veneer_b) \
259   DEF_STUB(a8_veneer_bl) \
260   DEF_STUB(a8_veneer_blx) \
261   DEF_STUB(v4_veneer_bx)
262
263 // Stub types.
264
265 #define DEF_STUB(x) arm_stub_##x,
266 typedef enum
267   {
268     arm_stub_none,
269     DEF_STUBS
270
271     // First reloc stub type.
272     arm_stub_reloc_first = arm_stub_long_branch_any_any,
273     // Last  reloc stub type.
274     arm_stub_reloc_last = arm_stub_long_branch_thumb_only_pic,
275
276     // First Cortex-A8 stub type.
277     arm_stub_cortex_a8_first = arm_stub_a8_veneer_b_cond,
278     // Last Cortex-A8 stub type.
279     arm_stub_cortex_a8_last = arm_stub_a8_veneer_blx,
280
281     // Last stub type.
282     arm_stub_type_last = arm_stub_v4_veneer_bx
283   } Stub_type;
284 #undef DEF_STUB
285
286 // Stub template class.  Templates are meant to be read-only objects.
287 // A stub template for a stub type contains all read-only attributes
288 // common to all stubs of the same type.
289
290 class Stub_template
291 {
292  public:
293   Stub_template(Stub_type, const Insn_template*, size_t);
294
295   ~Stub_template()
296   { }
297
298   // Return stub type.
299   Stub_type
300   type() const
301   { return this->type_; }
302
303   // Return an array of instruction templates.
304   const Insn_template*
305   insns() const
306   { return this->insns_; }
307
308   // Return size of template in number of instructions.
309   size_t
310   insn_count() const
311   { return this->insn_count_; }
312
313   // Return size of template in bytes.
314   size_t
315   size() const
316   { return this->size_; }
317
318   // Return alignment of the stub template.
319   unsigned
320   alignment() const
321   { return this->alignment_; }
322
323   // Return whether entry point is in thumb mode.
324   bool
325   entry_in_thumb_mode() const
326   { return this->entry_in_thumb_mode_; }
327
328   // Return number of relocations in this template.
329   size_t
330   reloc_count() const
331   { return this->relocs_.size(); }
332
333   // Return index of the I-th instruction with relocation.
334   size_t
335   reloc_insn_index(size_t i) const
336   {
337     gold_assert(i < this->relocs_.size());
338     return this->relocs_[i].first;
339   }
340
341   // Return the offset of the I-th instruction with relocation from the
342   // beginning of the stub.
343   section_size_type
344   reloc_offset(size_t i) const
345   {
346     gold_assert(i < this->relocs_.size());
347     return this->relocs_[i].second;
348   }
349
350  private:
351   // This contains information about an instruction template with a relocation
352   // and its offset from start of stub.
353   typedef std::pair<size_t, section_size_type> Reloc;
354
355   // A Stub_template may not be copied.  We want to share templates as much
356   // as possible.
357   Stub_template(const Stub_template&);
358   Stub_template& operator=(const Stub_template&);
359
360   // Stub type.
361   Stub_type type_;
362   // Points to an array of Insn_templates.
363   const Insn_template* insns_;
364   // Number of Insn_templates in insns_[].
365   size_t insn_count_;
366   // Size of templated instructions in bytes.
367   size_t size_;
368   // Alignment of templated instructions.
369   unsigned alignment_;
370   // Flag to indicate if entry is in thumb mode.
371   bool entry_in_thumb_mode_;
372   // A table of reloc instruction indices and offsets.  We can find these by
373   // looking at the instruction templates but we pre-compute and then stash
374   // them here for speed.
375   std::vector<Reloc> relocs_;
376 };
377
378 //
379 // A class for code stubs.  This is a base class for different type of
380 // stubs used in the ARM target.
381 //
382
383 class Stub
384 {
385  private:
386   static const section_offset_type invalid_offset =
387     static_cast<section_offset_type>(-1);
388
389  public:
390   Stub(const Stub_template* stub_template)
391     : stub_template_(stub_template), offset_(invalid_offset)
392   { }
393
394   virtual
395    ~Stub()
396   { }
397
398   // Return the stub template.
399   const Stub_template*
400   stub_template() const
401   { return this->stub_template_; }
402
403   // Return offset of code stub from beginning of its containing stub table.
404   section_offset_type
405   offset() const
406   {
407     gold_assert(this->offset_ != invalid_offset);
408     return this->offset_;
409   }
410
411   // Set offset of code stub from beginning of its containing stub table.
412   void
413   set_offset(section_offset_type offset)
414   { this->offset_ = offset; }
415
416   // Return the relocation target address of the i-th relocation in the
417   // stub.  This must be defined in a child class.
418   Arm_address
419   reloc_target(size_t i)
420   { return this->do_reloc_target(i); }
421
422   // Write a stub at output VIEW.  BIG_ENDIAN select how a stub is written.
423   void
424   write(unsigned char* view, section_size_type view_size, bool big_endian)
425   { this->do_write(view, view_size, big_endian); }
426
427   // Return the instruction for THUMB16_SPECIAL_TYPE instruction template
428   // for the i-th instruction.
429   uint16_t
430   thumb16_special(size_t i)
431   { return this->do_thumb16_special(i); }
432
433  protected:
434   // This must be defined in the child class.
435   virtual Arm_address
436   do_reloc_target(size_t) = 0;
437
438   // This may be overridden in the child class.
439   virtual void
440   do_write(unsigned char* view, section_size_type view_size, bool big_endian)
441   {
442     if (big_endian)
443       this->do_fixed_endian_write<true>(view, view_size);
444     else
445       this->do_fixed_endian_write<false>(view, view_size);
446   }
447
448   // This must be overridden if a child class uses the THUMB16_SPECIAL_TYPE
449   // instruction template.
450   virtual uint16_t
451   do_thumb16_special(size_t)
452   { gold_unreachable(); }
453
454  private:
455   // A template to implement do_write.
456   template<bool big_endian>
457   void inline
458   do_fixed_endian_write(unsigned char*, section_size_type);
459
460   // Its template.
461   const Stub_template* stub_template_;
462   // Offset within the section of containing this stub.
463   section_offset_type offset_;
464 };
465
466 // Reloc stub class.  These are stubs we use to fix up relocation because
467 // of limited branch ranges.
468
469 class Reloc_stub : public Stub
470 {
471  public:
472   static const unsigned int invalid_index = static_cast<unsigned int>(-1);
473   // We assume we never jump to this address.
474   static const Arm_address invalid_address = static_cast<Arm_address>(-1);
475
476   // Return destination address.
477   Arm_address
478   destination_address() const
479   {
480     gold_assert(this->destination_address_ != this->invalid_address);
481     return this->destination_address_;
482   }
483
484   // Set destination address.
485   void
486   set_destination_address(Arm_address address)
487   {
488     gold_assert(address != this->invalid_address);
489     this->destination_address_ = address;
490   }
491
492   // Reset destination address.
493   void
494   reset_destination_address()
495   { this->destination_address_ = this->invalid_address; }
496
497   // Determine stub type for a branch of a relocation of R_TYPE going
498   // from BRANCH_ADDRESS to BRANCH_TARGET.  If TARGET_IS_THUMB is set,
499   // the branch target is a thumb instruction.  TARGET is used for look
500   // up ARM-specific linker settings.
501   static Stub_type
502   stub_type_for_reloc(unsigned int r_type, Arm_address branch_address,
503                       Arm_address branch_target, bool target_is_thumb);
504
505   // Reloc_stub key.  A key is logically a triplet of a stub type, a symbol
506   // and an addend.  Since we treat global and local symbol differently, we
507   // use a Symbol object for a global symbol and a object-index pair for
508   // a local symbol.
509   class Key
510   {
511    public:
512     // If SYMBOL is not null, this is a global symbol, we ignore RELOBJ and
513     // R_SYM.  Otherwise, this is a local symbol and RELOBJ must non-NULL
514     // and R_SYM must not be invalid_index.
515     Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj,
516         unsigned int r_sym, int32_t addend)
517       : stub_type_(stub_type), addend_(addend)
518     {
519       if (symbol != NULL)
520         {
521           this->r_sym_ = Reloc_stub::invalid_index;
522           this->u_.symbol = symbol;
523         }
524       else
525         {
526           gold_assert(relobj != NULL && r_sym != invalid_index);
527           this->r_sym_ = r_sym;
528           this->u_.relobj = relobj;
529         }
530     }
531
532     ~Key()
533     { }
534
535     // Accessors: Keys are meant to be read-only object so no modifiers are
536     // provided.
537
538     // Return stub type.
539     Stub_type
540     stub_type() const
541     { return this->stub_type_; }
542
543     // Return the local symbol index or invalid_index.
544     unsigned int
545     r_sym() const
546     { return this->r_sym_; }
547
548     // Return the symbol if there is one.
549     const Symbol*
550     symbol() const
551     { return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; }
552
553     // Return the relobj if there is one.
554     const Relobj*
555     relobj() const
556     { return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; }
557
558     // Whether this equals to another key k.
559     bool
560     eq(const Key& k) const
561     {
562       return ((this->stub_type_ == k.stub_type_)
563               && (this->r_sym_ == k.r_sym_)
564               && ((this->r_sym_ != Reloc_stub::invalid_index)
565                   ? (this->u_.relobj == k.u_.relobj)
566                   : (this->u_.symbol == k.u_.symbol))
567               && (this->addend_ == k.addend_));
568     }
569
570     // Return a hash value.
571     size_t
572     hash_value() const
573     {
574       return (this->stub_type_
575               ^ this->r_sym_
576               ^ gold::string_hash<char>(
577                     (this->r_sym_ != Reloc_stub::invalid_index)
578                     ? this->u_.relobj->name().c_str()
579                     : this->u_.symbol->name())
580               ^ this->addend_);
581     }
582
583     // Functors for STL associative containers.
584     struct hash
585     {
586       size_t
587       operator()(const Key& k) const
588       { return k.hash_value(); }
589     };
590
591     struct equal_to
592     {
593       bool
594       operator()(const Key& k1, const Key& k2) const
595       { return k1.eq(k2); }
596     };
597
598     // Name of key.  This is mainly for debugging.
599     std::string
600     name() const ATTRIBUTE_UNUSED;
601
602    private:
603     // Stub type.
604     Stub_type stub_type_;
605     // If this is a local symbol, this is the index in the defining object.
606     // Otherwise, it is invalid_index for a global symbol.
607     unsigned int r_sym_;
608     // If r_sym_ is an invalid index, this points to a global symbol.
609     // Otherwise, it points to a relobj.  We used the unsized and target
610     // independent Symbol and Relobj classes instead of Sized_symbol<32> and
611     // Arm_relobj, in order to avoid making the stub class a template
612     // as most of the stub machinery is endianness-neutral.  However, it
613     // may require a bit of casting done by users of this class.
614     union
615     {
616       const Symbol* symbol;
617       const Relobj* relobj;
618     } u_;
619     // Addend associated with a reloc.
620     int32_t addend_;
621   };
622
623  protected:
624   // Reloc_stubs are created via a stub factory.  So these are protected.
625   Reloc_stub(const Stub_template* stub_template)
626     : Stub(stub_template), destination_address_(invalid_address)
627   { }
628
629   ~Reloc_stub()
630   { }
631
632   friend class Stub_factory;
633
634   // Return the relocation target address of the i-th relocation in the
635   // stub.
636   Arm_address
637   do_reloc_target(size_t i)
638   {
639     // All reloc stub have only one relocation.
640     gold_assert(i == 0);
641     return this->destination_address_;
642   }
643
644  private:
645   // Address of destination.
646   Arm_address destination_address_;
647 };
648
649 // Cortex-A8 stub class.  We need a Cortex-A8 stub to redirect any 32-bit
650 // THUMB branch that meets the following conditions:
651 //
652 // 1. The branch straddles across a page boundary. i.e. lower 12-bit of
653 //    branch address is 0xffe.
654 // 2. The branch target address is in the same page as the first word of the
655 //    branch.
656 // 3. The branch follows a 32-bit instruction which is not a branch.
657 //
658 // To do the fix up, we need to store the address of the branch instruction
659 // and its target at least.  We also need to store the original branch
660 // instruction bits for the condition code in a conditional branch.  The
661 // condition code is used in a special instruction template.  We also want
662 // to identify input sections needing Cortex-A8 workaround quickly.  We store
663 // extra information about object and section index of the code section
664 // containing a branch being fixed up.  The information is used to mark
665 // the code section when we finalize the Cortex-A8 stubs.
666 //
667
668 class Cortex_a8_stub : public Stub
669 {
670  public:
671   ~Cortex_a8_stub()
672   { }
673
674   // Return the object of the code section containing the branch being fixed
675   // up.
676   Relobj*
677   relobj() const
678   { return this->relobj_; }
679
680   // Return the section index of the code section containing the branch being
681   // fixed up.
682   unsigned int
683   shndx() const
684   { return this->shndx_; }
685
686   // Return the source address of stub.  This is the address of the original
687   // branch instruction.  LSB is 1 always set to indicate that it is a THUMB
688   // instruction.
689   Arm_address
690   source_address() const
691   { return this->source_address_; }
692
693   // Return the destination address of the stub.  This is the branch taken
694   // address of the original branch instruction.  LSB is 1 if it is a THUMB
695   // instruction address.
696   Arm_address
697   destination_address() const
698   { return this->destination_address_; }
699
700   // Return the instruction being fixed up.
701   uint32_t
702   original_insn() const
703   { return this->original_insn_; }
704
705  protected:
706   // Cortex_a8_stubs are created via a stub factory.  So these are protected.
707   Cortex_a8_stub(const Stub_template* stub_template, Relobj* relobj,
708                  unsigned int shndx, Arm_address source_address,
709                  Arm_address destination_address, uint32_t original_insn)
710     : Stub(stub_template), relobj_(relobj), shndx_(shndx),
711       source_address_(source_address | 1U),
712       destination_address_(destination_address),
713       original_insn_(original_insn)
714   { }
715
716   friend class Stub_factory;
717
718   // Return the relocation target address of the i-th relocation in the
719   // stub.
720   Arm_address
721   do_reloc_target(size_t i)
722   {
723     if (this->stub_template()->type() == arm_stub_a8_veneer_b_cond)
724       {
725         // The conditional branch veneer has two relocations.
726         gold_assert(i < 2);
727         return i == 0 ? this->source_address_ + 4 : this->destination_address_;
728       }
729     else
730       {
731         // All other Cortex-A8 stubs have only one relocation.
732         gold_assert(i == 0);
733         return this->destination_address_;
734       }
735   }
736
737   // Return an instruction for the THUMB16_SPECIAL_TYPE instruction template.
738   uint16_t
739   do_thumb16_special(size_t);
740
741  private:
742   // Object of the code section containing the branch being fixed up.
743   Relobj* relobj_;
744   // Section index of the code section containing the branch begin fixed up.
745   unsigned int shndx_;
746   // Source address of original branch.
747   Arm_address source_address_;
748   // Destination address of the original branch.
749   Arm_address destination_address_;
750   // Original branch instruction.  This is needed for copying the condition
751   // code from a condition branch to its stub.
752   uint32_t original_insn_;
753 };
754
755 // ARMv4 BX Rx branch relocation stub class.
756 class Arm_v4bx_stub : public Stub
757 {
758  public:
759   ~Arm_v4bx_stub()
760   { }
761
762   // Return the associated register.
763   uint32_t
764   reg() const
765   { return this->reg_; }
766
767  protected:
768   // Arm V4BX stubs are created via a stub factory.  So these are protected.
769   Arm_v4bx_stub(const Stub_template* stub_template, const uint32_t reg)
770     : Stub(stub_template), reg_(reg)
771   { }
772
773   friend class Stub_factory;
774
775   // Return the relocation target address of the i-th relocation in the
776   // stub.
777   Arm_address
778   do_reloc_target(size_t)
779   { gold_unreachable(); }
780
781   // This may be overridden in the child class.
782   virtual void
783   do_write(unsigned char* view, section_size_type view_size, bool big_endian)
784   {
785     if (big_endian)
786       this->do_fixed_endian_v4bx_write<true>(view, view_size);
787     else
788       this->do_fixed_endian_v4bx_write<false>(view, view_size);
789   }
790
791  private:
792   // A template to implement do_write.
793   template<bool big_endian>
794   void inline
795   do_fixed_endian_v4bx_write(unsigned char* view, section_size_type)
796   {
797     const Insn_template* insns = this->stub_template()->insns();
798     elfcpp::Swap<32, big_endian>::writeval(view,
799                                            (insns[0].data()
800                                            + (this->reg_ << 16)));
801     view += insns[0].size();
802     elfcpp::Swap<32, big_endian>::writeval(view,
803                                            (insns[1].data() + this->reg_));
804     view += insns[1].size();
805     elfcpp::Swap<32, big_endian>::writeval(view,
806                                            (insns[2].data() + this->reg_));
807   }
808
809   // A register index (r0-r14), which is associated with the stub.
810   uint32_t reg_;
811 };
812
813 // Stub factory class.
814
815 class Stub_factory
816 {
817  public:
818   // Return the unique instance of this class.
819   static const Stub_factory&
820   get_instance()
821   {
822     static Stub_factory singleton;
823     return singleton;
824   }
825
826   // Make a relocation stub.
827   Reloc_stub*
828   make_reloc_stub(Stub_type stub_type) const
829   {
830     gold_assert(stub_type >= arm_stub_reloc_first
831                 && stub_type <= arm_stub_reloc_last);
832     return new Reloc_stub(this->stub_templates_[stub_type]);
833   }
834
835   // Make a Cortex-A8 stub.
836   Cortex_a8_stub*
837   make_cortex_a8_stub(Stub_type stub_type, Relobj* relobj, unsigned int shndx,
838                       Arm_address source, Arm_address destination,
839                       uint32_t original_insn) const
840   {
841     gold_assert(stub_type >= arm_stub_cortex_a8_first
842                 && stub_type <= arm_stub_cortex_a8_last);
843     return new Cortex_a8_stub(this->stub_templates_[stub_type], relobj, shndx,
844                               source, destination, original_insn);
845   }
846
847   // Make an ARM V4BX relocation stub.
848   // This method creates a stub from the arm_stub_v4_veneer_bx template only.
849   Arm_v4bx_stub*
850   make_arm_v4bx_stub(uint32_t reg) const
851   {
852     gold_assert(reg < 0xf);
853     return new Arm_v4bx_stub(this->stub_templates_[arm_stub_v4_veneer_bx],
854                              reg);
855   }
856
857  private:
858   // Constructor and destructor are protected since we only return a single
859   // instance created in Stub_factory::get_instance().
860
861   Stub_factory();
862
863   // A Stub_factory may not be copied since it is a singleton.
864   Stub_factory(const Stub_factory&);
865   Stub_factory& operator=(Stub_factory&);
866
867   // Stub templates.  These are initialized in the constructor.
868   const Stub_template* stub_templates_[arm_stub_type_last+1];
869 };
870
871 // A class to hold stubs for the ARM target.
872
873 template<bool big_endian>
874 class Stub_table : public Output_data
875 {
876  public:
877   Stub_table(Arm_input_section<big_endian>* owner)
878     : Output_data(), owner_(owner), reloc_stubs_(), reloc_stubs_size_(0),
879       reloc_stubs_addralign_(1), cortex_a8_stubs_(), arm_v4bx_stubs_(0xf),
880       prev_data_size_(0), prev_addralign_(1)
881   { }
882
883   ~Stub_table()
884   { }
885
886   // Owner of this stub table.
887   Arm_input_section<big_endian>*
888   owner() const
889   { return this->owner_; }
890
891   // Whether this stub table is empty.
892   bool
893   empty() const
894   {
895     return (this->reloc_stubs_.empty()
896             && this->cortex_a8_stubs_.empty()
897             && this->arm_v4bx_stubs_.empty());
898   }
899
900   // Return the current data size.
901   off_t
902   current_data_size() const
903   { return this->current_data_size_for_child(); }
904
905   // Add a STUB using KEY.  The caller is responsible for avoiding addition
906   // if a STUB with the same key has already been added.
907   void
908   add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key)
909   {
910     const Stub_template* stub_template = stub->stub_template();
911     gold_assert(stub_template->type() == key.stub_type());
912     this->reloc_stubs_[key] = stub;
913
914     // Assign stub offset early.  We can do this because we never remove
915     // reloc stubs and they are in the beginning of the stub table.
916     uint64_t align = stub_template->alignment();
917     this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_, align);
918     stub->set_offset(this->reloc_stubs_size_);
919     this->reloc_stubs_size_ += stub_template->size();
920     this->reloc_stubs_addralign_ =
921       std::max(this->reloc_stubs_addralign_, align);
922   }
923
924   // Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS.
925   // The caller is responsible for avoiding addition if a STUB with the same
926   // address has already been added.
927   void
928   add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub)
929   {
930     std::pair<Arm_address, Cortex_a8_stub*> value(address, stub);
931     this->cortex_a8_stubs_.insert(value);
932   }
933
934   // Add an ARM V4BX relocation stub. A register index will be retrieved
935   // from the stub.
936   void
937   add_arm_v4bx_stub(Arm_v4bx_stub* stub)
938   {
939     gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL);
940     this->arm_v4bx_stubs_[stub->reg()] = stub;
941   }
942
943   // Remove all Cortex-A8 stubs.
944   void
945   remove_all_cortex_a8_stubs();
946
947   // Look up a relocation stub using KEY.  Return NULL if there is none.
948   Reloc_stub*
949   find_reloc_stub(const Reloc_stub::Key& key) const
950   {
951     typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
952     return (p != this->reloc_stubs_.end()) ? p->second : NULL;
953   }
954
955   // Look up an arm v4bx relocation stub using the register index.
956   // Return NULL if there is none.
957   Arm_v4bx_stub*
958   find_arm_v4bx_stub(const uint32_t reg) const
959   {
960     gold_assert(reg < 0xf);
961     return this->arm_v4bx_stubs_[reg];
962   }
963
964   // Relocate stubs in this stub table.
965   void
966   relocate_stubs(const Relocate_info<32, big_endian>*,
967                  Target_arm<big_endian>*, Output_section*,
968                  unsigned char*, Arm_address, section_size_type);
969
970   // Update data size and alignment at the end of a relaxation pass.  Return
971   // true if either data size or alignment is different from that of the
972   // previous relaxation pass.
973   bool
974   update_data_size_and_addralign();
975
976   // Finalize stubs.  Set the offsets of all stubs and mark input sections
977   // needing the Cortex-A8 workaround.
978   void
979   finalize_stubs();
980
981   // Apply Cortex-A8 workaround to an address range.
982   void
983   apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*,
984                                               unsigned char*, Arm_address,
985                                               section_size_type);
986
987  protected:
988   // Write out section contents.
989   void
990   do_write(Output_file*);
991
992   // Return the required alignment.
993   uint64_t
994   do_addralign() const
995   { return this->prev_addralign_; }
996
997   // Reset address and file offset.
998   void
999   do_reset_address_and_file_offset()
1000   { this->set_current_data_size_for_child(this->prev_data_size_); }
1001
1002   // Set final data size.
1003   void
1004   set_final_data_size()
1005   { this->set_data_size(this->current_data_size()); }
1006
1007  private:
1008   // Relocate one stub.
1009   void
1010   relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
1011                 Target_arm<big_endian>*, Output_section*,
1012                 unsigned char*, Arm_address, section_size_type);
1013
1014   // Unordered map of relocation stubs.
1015   typedef
1016     Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
1017                   Reloc_stub::Key::equal_to>
1018     Reloc_stub_map;
1019
1020   // List of Cortex-A8 stubs ordered by addresses of branches being
1021   // fixed up in output.
1022   typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list;
1023   // List of Arm V4BX relocation stubs ordered by associated registers.
1024   typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list;
1025
1026   // Owner of this stub table.
1027   Arm_input_section<big_endian>* owner_;
1028   // The relocation stubs.
1029   Reloc_stub_map reloc_stubs_;
1030   // Size of reloc stubs.
1031   off_t reloc_stubs_size_;
1032   // Maximum address alignment of reloc stubs.
1033   uint64_t reloc_stubs_addralign_;
1034   // The cortex_a8_stubs.
1035   Cortex_a8_stub_list cortex_a8_stubs_;
1036   // The Arm V4BX relocation stubs.
1037   Arm_v4bx_stub_list arm_v4bx_stubs_;
1038   // data size of this in the previous pass.
1039   off_t prev_data_size_;
1040   // address alignment of this in the previous pass.
1041   uint64_t prev_addralign_;
1042 };
1043
1044 // Arm_exidx_cantunwind class.  This represents an EXIDX_CANTUNWIND entry
1045 // we add to the end of an EXIDX input section that goes into the output.
1046
1047 class Arm_exidx_cantunwind : public Output_section_data
1048 {
1049  public:
1050   Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
1051     : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
1052   { }
1053
1054   // Return the object containing the section pointed by this.
1055   Relobj*
1056   relobj() const
1057   { return this->relobj_; }
1058
1059   // Return the section index of the section pointed by this.
1060   unsigned int
1061   shndx() const
1062   { return this->shndx_; }
1063
1064  protected:
1065   void
1066   do_write(Output_file* of)
1067   {
1068     if (parameters->target().is_big_endian())
1069       this->do_fixed_endian_write<true>(of);
1070     else
1071       this->do_fixed_endian_write<false>(of);
1072   }
1073
1074   // Write to a map file.
1075   void
1076   do_print_to_mapfile(Mapfile* mapfile) const
1077   { mapfile->print_output_data(this, _("** ARM cantunwind")); }
1078
1079  private:
1080   // Implement do_write for a given endianness.
1081   template<bool big_endian>
1082   void inline
1083   do_fixed_endian_write(Output_file*);
1084
1085   // The object containing the section pointed by this.
1086   Relobj* relobj_;
1087   // The section index of the section pointed by this.
1088   unsigned int shndx_;
1089 };
1090
1091 // During EXIDX coverage fix-up, we compact an EXIDX section.  The
1092 // Offset map is used to map input section offset within the EXIDX section
1093 // to the output offset from the start of this EXIDX section.
1094
1095 typedef std::map<section_offset_type, section_offset_type>
1096         Arm_exidx_section_offset_map;
1097
1098 // Arm_exidx_merged_section class.  This represents an EXIDX input section
1099 // with some of its entries merged.
1100
1101 class Arm_exidx_merged_section : public Output_relaxed_input_section
1102 {
1103  public:
1104   // Constructor for Arm_exidx_merged_section.
1105   // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
1106   // SECTION_OFFSET_MAP points to a section offset map describing how
1107   // parts of the input section are mapped to output.  DELETED_BYTES is
1108   // the number of bytes deleted from the EXIDX input section.
1109   Arm_exidx_merged_section(
1110       const Arm_exidx_input_section& exidx_input_section,
1111       const Arm_exidx_section_offset_map& section_offset_map,
1112       uint32_t deleted_bytes);
1113
1114   // Build output contents.
1115   void
1116   build_contents(const unsigned char*, section_size_type);
1117
1118   // Return the original EXIDX input section.
1119   const Arm_exidx_input_section&
1120   exidx_input_section() const
1121   { return this->exidx_input_section_; }
1122
1123   // Return the section offset map.
1124   const Arm_exidx_section_offset_map&
1125   section_offset_map() const
1126   { return this->section_offset_map_; }
1127
1128  protected:
1129   // Write merged section into file OF.
1130   void
1131   do_write(Output_file* of);
1132
1133   bool
1134   do_output_offset(const Relobj*, unsigned int, section_offset_type,
1135                   section_offset_type*) const;
1136
1137  private:
1138   // Original EXIDX input section.
1139   const Arm_exidx_input_section& exidx_input_section_;
1140   // Section offset map.
1141   const Arm_exidx_section_offset_map& section_offset_map_;
1142   // Merged section contents.  We need to keep build the merged section
1143   // and save it here to avoid accessing the original EXIDX section when
1144   // we cannot lock the sections' object.
1145   unsigned char* section_contents_;
1146 };
1147
1148 // A class to wrap an ordinary input section containing executable code.
1149
1150 template<bool big_endian>
1151 class Arm_input_section : public Output_relaxed_input_section
1152 {
1153  public:
1154   Arm_input_section(Relobj* relobj, unsigned int shndx)
1155     : Output_relaxed_input_section(relobj, shndx, 1),
1156       original_addralign_(1), original_size_(0), stub_table_(NULL),
1157       original_contents_(NULL)
1158   { }
1159
1160   ~Arm_input_section()
1161   { delete[] this->original_contents_; }
1162
1163   // Initialize.
1164   void
1165   init();
1166
1167   // Whether this is a stub table owner.
1168   bool
1169   is_stub_table_owner() const
1170   { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
1171
1172   // Return the stub table.
1173   Stub_table<big_endian>*
1174   stub_table() const
1175   { return this->stub_table_; }
1176
1177   // Set the stub_table.
1178   void
1179   set_stub_table(Stub_table<big_endian>* stub_table)
1180   { this->stub_table_ = stub_table; }
1181
1182   // Downcast a base pointer to an Arm_input_section pointer.  This is
1183   // not type-safe but we only use Arm_input_section not the base class.
1184   static Arm_input_section<big_endian>*
1185   as_arm_input_section(Output_relaxed_input_section* poris)
1186   { return static_cast<Arm_input_section<big_endian>*>(poris); }
1187
1188   // Return the original size of the section.
1189   uint32_t
1190   original_size() const
1191   { return this->original_size_; }
1192
1193  protected:
1194   // Write data to output file.
1195   void
1196   do_write(Output_file*);
1197
1198   // Return required alignment of this.
1199   uint64_t
1200   do_addralign() const
1201   {
1202     if (this->is_stub_table_owner())
1203       return std::max(this->stub_table_->addralign(),
1204                       static_cast<uint64_t>(this->original_addralign_));
1205     else
1206       return this->original_addralign_;
1207   }
1208
1209   // Finalize data size.
1210   void
1211   set_final_data_size();
1212
1213   // Reset address and file offset.
1214   void
1215   do_reset_address_and_file_offset();
1216
1217   // Output offset.
1218   bool
1219   do_output_offset(const Relobj* object, unsigned int shndx,
1220                    section_offset_type offset,
1221                    section_offset_type* poutput) const
1222   {
1223     if ((object == this->relobj())
1224         && (shndx == this->shndx())
1225         && (offset >= 0)
1226         && (offset <=
1227             convert_types<section_offset_type, uint32_t>(this->original_size_)))
1228       {
1229         *poutput = offset;
1230         return true;
1231       }
1232     else
1233       return false;
1234   }
1235
1236  private:
1237   // Copying is not allowed.
1238   Arm_input_section(const Arm_input_section&);
1239   Arm_input_section& operator=(const Arm_input_section&);
1240
1241   // Address alignment of the original input section.
1242   uint32_t original_addralign_;
1243   // Section size of the original input section.
1244   uint32_t original_size_;
1245   // Stub table.
1246   Stub_table<big_endian>* stub_table_;
1247   // Original section contents.  We have to make a copy here since the file
1248   // containing the original section may not be locked when we need to access
1249   // the contents.
1250   unsigned char* original_contents_;
1251 };
1252
1253 // Arm_exidx_fixup class.  This is used to define a number of methods
1254 // and keep states for fixing up EXIDX coverage.
1255
1256 class Arm_exidx_fixup
1257 {
1258  public:
1259   Arm_exidx_fixup(Output_section* exidx_output_section,
1260                   bool merge_exidx_entries = true)
1261     : exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE),
1262       last_inlined_entry_(0), last_input_section_(NULL),
1263       section_offset_map_(NULL), first_output_text_section_(NULL),
1264       merge_exidx_entries_(merge_exidx_entries)
1265   { }
1266
1267   ~Arm_exidx_fixup()
1268   { delete this->section_offset_map_; }
1269
1270   // Process an EXIDX section for entry merging.  SECTION_CONTENTS points
1271   // to the EXIDX contents and SECTION_SIZE is the size of the contents. Return
1272   // number of bytes to be deleted in output.  If parts of the input EXIDX
1273   // section are merged a heap allocated Arm_exidx_section_offset_map is store
1274   // in the located PSECTION_OFFSET_MAP.   The caller owns the map and is
1275   // responsible for releasing it.
1276   template<bool big_endian>
1277   uint32_t
1278   process_exidx_section(const Arm_exidx_input_section* exidx_input_section,
1279                         const unsigned char* section_contents,
1280                         section_size_type section_size,
1281                         Arm_exidx_section_offset_map** psection_offset_map);
1282
1283   // Append an EXIDX_CANTUNWIND entry pointing at the end of the last
1284   // input section, if there is not one already.
1285   void
1286   add_exidx_cantunwind_as_needed();
1287
1288   // Return the output section for the text section which is linked to the
1289   // first exidx input in output.
1290   Output_section*
1291   first_output_text_section() const
1292   { return this->first_output_text_section_; }
1293
1294  private:
1295   // Copying is not allowed.
1296   Arm_exidx_fixup(const Arm_exidx_fixup&);
1297   Arm_exidx_fixup& operator=(const Arm_exidx_fixup&);
1298
1299   // Type of EXIDX unwind entry.
1300   enum Unwind_type
1301   {
1302     // No type.
1303     UT_NONE,
1304     // EXIDX_CANTUNWIND.
1305     UT_EXIDX_CANTUNWIND,
1306     // Inlined entry.
1307     UT_INLINED_ENTRY,
1308     // Normal entry.
1309     UT_NORMAL_ENTRY,
1310   };
1311
1312   // Process an EXIDX entry.  We only care about the second word of the
1313   // entry.  Return true if the entry can be deleted.
1314   bool
1315   process_exidx_entry(uint32_t second_word);
1316
1317   // Update the current section offset map during EXIDX section fix-up.
1318   // If there is no map, create one.  INPUT_OFFSET is the offset of a
1319   // reference point, DELETED_BYTES is the number of deleted by in the
1320   // section so far.  If DELETE_ENTRY is true, the reference point and
1321   // all offsets after the previous reference point are discarded.
1322   void
1323   update_offset_map(section_offset_type input_offset,
1324                     section_size_type deleted_bytes, bool delete_entry);
1325
1326   // EXIDX output section.
1327   Output_section* exidx_output_section_;
1328   // Unwind type of the last EXIDX entry processed.
1329   Unwind_type last_unwind_type_;
1330   // Last seen inlined EXIDX entry.
1331   uint32_t last_inlined_entry_;
1332   // Last processed EXIDX input section.
1333   const Arm_exidx_input_section* last_input_section_;
1334   // Section offset map created in process_exidx_section.
1335   Arm_exidx_section_offset_map* section_offset_map_;
1336   // Output section for the text section which is linked to the first exidx
1337   // input in output.
1338   Output_section* first_output_text_section_;
1339
1340   bool merge_exidx_entries_;
1341 };
1342
1343 // Arm output section class.  This is defined mainly to add a number of
1344 // stub generation methods.
1345
1346 template<bool big_endian>
1347 class Arm_output_section : public Output_section
1348 {
1349  public:
1350   typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list;
1351
1352   // We need to force SHF_LINK_ORDER in a SHT_ARM_EXIDX section.
1353   Arm_output_section(const char* name, elfcpp::Elf_Word type,
1354                      elfcpp::Elf_Xword flags)
1355     : Output_section(name, type,
1356                      (type == elfcpp::SHT_ARM_EXIDX
1357                       ? flags | elfcpp::SHF_LINK_ORDER
1358                       : flags))
1359   {
1360     if (type == elfcpp::SHT_ARM_EXIDX)
1361       this->set_always_keeps_input_sections();
1362   }
1363
1364   ~Arm_output_section()
1365   { }
1366
1367   // Group input sections for stub generation.
1368   void
1369   group_sections(section_size_type, bool, Target_arm<big_endian>*, const Task*);
1370
1371   // Downcast a base pointer to an Arm_output_section pointer.  This is
1372   // not type-safe but we only use Arm_output_section not the base class.
1373   static Arm_output_section<big_endian>*
1374   as_arm_output_section(Output_section* os)
1375   { return static_cast<Arm_output_section<big_endian>*>(os); }
1376
1377   // Append all input text sections in this into LIST.
1378   void
1379   append_text_sections_to_list(Text_section_list* list);
1380
1381   // Fix EXIDX coverage of this EXIDX output section.  SORTED_TEXT_SECTION
1382   // is a list of text input sections sorted in ascending order of their
1383   // output addresses.
1384   void
1385   fix_exidx_coverage(Layout* layout,
1386                      const Text_section_list& sorted_text_section,
1387                      Symbol_table* symtab,
1388                      bool merge_exidx_entries,
1389                      const Task* task);
1390
1391   // Link an EXIDX section into its corresponding text section.
1392   void
1393   set_exidx_section_link();
1394
1395  private:
1396   // For convenience.
1397   typedef Output_section::Input_section Input_section;
1398   typedef Output_section::Input_section_list Input_section_list;
1399
1400   // Create a stub group.
1401   void create_stub_group(Input_section_list::const_iterator,
1402                          Input_section_list::const_iterator,
1403                          Input_section_list::const_iterator,
1404                          Target_arm<big_endian>*,
1405                          std::vector<Output_relaxed_input_section*>*,
1406                          const Task* task);
1407 };
1408
1409 // Arm_exidx_input_section class.  This represents an EXIDX input section.
1410
1411 class Arm_exidx_input_section
1412 {
1413  public:
1414   static const section_offset_type invalid_offset =
1415     static_cast<section_offset_type>(-1);
1416
1417   Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1418                           unsigned int link, uint32_t size,
1419                           uint32_t addralign, uint32_t text_size)
1420     : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1421       addralign_(addralign), text_size_(text_size), has_errors_(false)
1422   { }
1423
1424   ~Arm_exidx_input_section()
1425   { }
1426
1427   // Accessors:  This is a read-only class.
1428
1429   // Return the object containing this EXIDX input section.
1430   Relobj*
1431   relobj() const
1432   { return this->relobj_; }
1433
1434   // Return the section index of this EXIDX input section.
1435   unsigned int
1436   shndx() const
1437   { return this->shndx_; }
1438
1439   // Return the section index of linked text section in the same object.
1440   unsigned int
1441   link() const
1442   { return this->link_; }
1443
1444   // Return size of the EXIDX input section.
1445   uint32_t
1446   size() const
1447   { return this->size_; }
1448
1449   // Return address alignment of EXIDX input section.
1450   uint32_t
1451   addralign() const
1452   { return this->addralign_; }
1453
1454   // Return size of the associated text input section.
1455   uint32_t
1456   text_size() const
1457   { return this->text_size_; }
1458
1459   // Whether there are any errors in the EXIDX input section.
1460   bool
1461   has_errors() const
1462   { return this->has_errors_; }
1463
1464   // Set has-errors flag.
1465   void
1466   set_has_errors()
1467   { this->has_errors_ = true; }
1468
1469  private:
1470   // Object containing this.
1471   Relobj* relobj_;
1472   // Section index of this.
1473   unsigned int shndx_;
1474   // text section linked to this in the same object.
1475   unsigned int link_;
1476   // Size of this.  For ARM 32-bit is sufficient.
1477   uint32_t size_;
1478   // Address alignment of this.  For ARM 32-bit is sufficient.
1479   uint32_t addralign_;
1480   // Size of associated text section.
1481   uint32_t text_size_;
1482   // Whether this has any errors.
1483   bool has_errors_;
1484 };
1485
1486 // Arm_relobj class.
1487
1488 template<bool big_endian>
1489 class Arm_relobj : public Sized_relobj_file<32, big_endian>
1490 {
1491  public:
1492   static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1493
1494   Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1495              const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1496     : Sized_relobj_file<32, big_endian>(name, input_file, offset, ehdr),
1497       stub_tables_(), local_symbol_is_thumb_function_(),
1498       attributes_section_data_(NULL), mapping_symbols_info_(),
1499       section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1500       output_local_symbol_count_needs_update_(false),
1501       merge_flags_and_attributes_(true)
1502   { }
1503
1504   ~Arm_relobj()
1505   { delete this->attributes_section_data_; }
1506
1507   // Return the stub table of the SHNDX-th section if there is one.
1508   Stub_table<big_endian>*
1509   stub_table(unsigned int shndx) const
1510   {
1511     gold_assert(shndx < this->stub_tables_.size());
1512     return this->stub_tables_[shndx];
1513   }
1514
1515   // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1516   void
1517   set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1518   {
1519     gold_assert(shndx < this->stub_tables_.size());
1520     this->stub_tables_[shndx] = stub_table;
1521   }
1522
1523   // Whether a local symbol is a THUMB function.  R_SYM is the symbol table
1524   // index.  This is only valid after do_count_local_symbol is called.
1525   bool
1526   local_symbol_is_thumb_function(unsigned int r_sym) const
1527   {
1528     gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1529     return this->local_symbol_is_thumb_function_[r_sym];
1530   }
1531
1532   // Scan all relocation sections for stub generation.
1533   void
1534   scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1535                           const Layout*);
1536
1537   // Convert regular input section with index SHNDX to a relaxed section.
1538   void
1539   convert_input_section_to_relaxed_section(unsigned shndx)
1540   {
1541     // The stubs have relocations and we need to process them after writing
1542     // out the stubs.  So relocation now must follow section write.
1543     this->set_section_offset(shndx, -1ULL);
1544     this->set_relocs_must_follow_section_writes();
1545   }
1546
1547   // Downcast a base pointer to an Arm_relobj pointer.  This is
1548   // not type-safe but we only use Arm_relobj not the base class.
1549   static Arm_relobj<big_endian>*
1550   as_arm_relobj(Relobj* relobj)
1551   { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1552
1553   // Processor-specific flags in ELF file header.  This is valid only after
1554   // reading symbols.
1555   elfcpp::Elf_Word
1556   processor_specific_flags() const
1557   { return this->processor_specific_flags_; }
1558
1559   // Attribute section data  This is the contents of the .ARM.attribute section
1560   // if there is one.
1561   const Attributes_section_data*
1562   attributes_section_data() const
1563   { return this->attributes_section_data_; }
1564
1565   // Mapping symbol location.
1566   typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1567
1568   // Functor for STL container.
1569   struct Mapping_symbol_position_less
1570   {
1571     bool
1572     operator()(const Mapping_symbol_position& p1,
1573                const Mapping_symbol_position& p2) const
1574     {
1575       return (p1.first < p2.first
1576               || (p1.first == p2.first && p1.second < p2.second));
1577     }
1578   };
1579
1580   // We only care about the first character of a mapping symbol, so
1581   // we only store that instead of the whole symbol name.
1582   typedef std::map<Mapping_symbol_position, char,
1583                    Mapping_symbol_position_less> Mapping_symbols_info;
1584
1585   // Whether a section contains any Cortex-A8 workaround.
1586   bool
1587   section_has_cortex_a8_workaround(unsigned int shndx) const
1588   {
1589     return (this->section_has_cortex_a8_workaround_ != NULL
1590             && (*this->section_has_cortex_a8_workaround_)[shndx]);
1591   }
1592
1593   // Mark a section that has Cortex-A8 workaround.
1594   void
1595   mark_section_for_cortex_a8_workaround(unsigned int shndx)
1596   {
1597     if (this->section_has_cortex_a8_workaround_ == NULL)
1598       this->section_has_cortex_a8_workaround_ =
1599         new std::vector<bool>(this->shnum(), false);
1600     (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1601   }
1602
1603   // Return the EXIDX section of an text section with index SHNDX or NULL
1604   // if the text section has no associated EXIDX section.
1605   const Arm_exidx_input_section*
1606   exidx_input_section_by_link(unsigned int shndx) const
1607   {
1608     Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1609     return ((p != this->exidx_section_map_.end()
1610              && p->second->link() == shndx)
1611             ? p->second
1612             : NULL);
1613   }
1614
1615   // Return the EXIDX section with index SHNDX or NULL if there is none.
1616   const Arm_exidx_input_section*
1617   exidx_input_section_by_shndx(unsigned shndx) const
1618   {
1619     Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1620     return ((p != this->exidx_section_map_.end()
1621              && p->second->shndx() == shndx)
1622             ? p->second
1623             : NULL);
1624   }
1625
1626   // Whether output local symbol count needs updating.
1627   bool
1628   output_local_symbol_count_needs_update() const
1629   { return this->output_local_symbol_count_needs_update_; }
1630
1631   // Set output_local_symbol_count_needs_update flag to be true.
1632   void
1633   set_output_local_symbol_count_needs_update()
1634   { this->output_local_symbol_count_needs_update_ = true; }
1635
1636   // Update output local symbol count at the end of relaxation.
1637   void
1638   update_output_local_symbol_count();
1639
1640   // Whether we want to merge processor-specific flags and attributes.
1641   bool
1642   merge_flags_and_attributes() const
1643   { return this->merge_flags_and_attributes_; }
1644
1645   // Export list of EXIDX section indices.
1646   void
1647   get_exidx_shndx_list(std::vector<unsigned int>* list) const
1648   {
1649     list->clear();
1650     for (Exidx_section_map::const_iterator p = this->exidx_section_map_.begin();
1651          p != this->exidx_section_map_.end();
1652          ++p)
1653       {
1654         if (p->second->shndx() == p->first)
1655           list->push_back(p->first);
1656       }
1657     // Sort list to make result independent of implementation of map.
1658     std::sort(list->begin(), list->end());
1659   }
1660
1661  protected:
1662   // Post constructor setup.
1663   void
1664   do_setup()
1665   {
1666     // Call parent's setup method.
1667     Sized_relobj_file<32, big_endian>::do_setup();
1668
1669     // Initialize look-up tables.
1670     Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1671     this->stub_tables_.swap(empty_stub_table_list);
1672   }
1673
1674   // Count the local symbols.
1675   void
1676   do_count_local_symbols(Stringpool_template<char>*,
1677                          Stringpool_template<char>*);
1678
1679   void
1680   do_relocate_sections(
1681       const Symbol_table* symtab, const Layout* layout,
1682       const unsigned char* pshdrs, Output_file* of,
1683       typename Sized_relobj_file<32, big_endian>::Views* pivews);
1684
1685   // Read the symbol information.
1686   void
1687   do_read_symbols(Read_symbols_data* sd);
1688
1689   // Process relocs for garbage collection.
1690   void
1691   do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1692
1693  private:
1694
1695   // Whether a section needs to be scanned for relocation stubs.
1696   bool
1697   section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1698                                     const Relobj::Output_sections&,
1699                                     const Symbol_table*, const unsigned char*);
1700
1701   // Whether a section is a scannable text section.
1702   bool
1703   section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1704                        const Output_section*, const Symbol_table*);
1705
1706   // Whether a section needs to be scanned for the Cortex-A8 erratum.
1707   bool
1708   section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1709                                         unsigned int, Output_section*,
1710                                         const Symbol_table*);
1711
1712   // Scan a section for the Cortex-A8 erratum.
1713   void
1714   scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1715                                      unsigned int, Output_section*,
1716                                      Target_arm<big_endian>*);
1717
1718   // Find the linked text section of an EXIDX section by looking at the
1719   // first relocation of the EXIDX section.  PSHDR points to the section
1720   // headers of a relocation section and PSYMS points to the local symbols.
1721   // PSHNDX points to a location storing the text section index if found.
1722   // Return whether we can find the linked section.
1723   bool
1724   find_linked_text_section(const unsigned char* pshdr,
1725                            const unsigned char* psyms, unsigned int* pshndx);
1726
1727   //
1728   // Make a new Arm_exidx_input_section object for EXIDX section with
1729   // index SHNDX and section header SHDR.  TEXT_SHNDX is the section
1730   // index of the linked text section.
1731   void
1732   make_exidx_input_section(unsigned int shndx,
1733                            const elfcpp::Shdr<32, big_endian>& shdr,
1734                            unsigned int text_shndx,
1735                            const elfcpp::Shdr<32, big_endian>& text_shdr);
1736
1737   // Return the output address of either a plain input section or a
1738   // relaxed input section.  SHNDX is the section index.
1739   Arm_address
1740   simple_input_section_output_address(unsigned int, Output_section*);
1741
1742   typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1743   typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1744     Exidx_section_map;
1745
1746   // List of stub tables.
1747   Stub_table_list stub_tables_;
1748   // Bit vector to tell if a local symbol is a thumb function or not.
1749   // This is only valid after do_count_local_symbol is called.
1750   std::vector<bool> local_symbol_is_thumb_function_;
1751   // processor-specific flags in ELF file header.
1752   elfcpp::Elf_Word processor_specific_flags_;
1753   // Object attributes if there is an .ARM.attributes section or NULL.
1754   Attributes_section_data* attributes_section_data_;
1755   // Mapping symbols information.
1756   Mapping_symbols_info mapping_symbols_info_;
1757   // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1758   std::vector<bool>* section_has_cortex_a8_workaround_;
1759   // Map a text section to its associated .ARM.exidx section, if there is one.
1760   Exidx_section_map exidx_section_map_;
1761   // Whether output local symbol count needs updating.
1762   bool output_local_symbol_count_needs_update_;
1763   // Whether we merge processor flags and attributes of this object to
1764   // output.
1765   bool merge_flags_and_attributes_;
1766 };
1767
1768 // Arm_dynobj class.
1769
1770 template<bool big_endian>
1771 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1772 {
1773  public:
1774   Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1775              const elfcpp::Ehdr<32, big_endian>& ehdr)
1776     : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1777       processor_specific_flags_(0), attributes_section_data_(NULL)
1778   { }
1779
1780   ~Arm_dynobj()
1781   { delete this->attributes_section_data_; }
1782
1783   // Downcast a base pointer to an Arm_relobj pointer.  This is
1784   // not type-safe but we only use Arm_relobj not the base class.
1785   static Arm_dynobj<big_endian>*
1786   as_arm_dynobj(Dynobj* dynobj)
1787   { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1788
1789   // Processor-specific flags in ELF file header.  This is valid only after
1790   // reading symbols.
1791   elfcpp::Elf_Word
1792   processor_specific_flags() const
1793   { return this->processor_specific_flags_; }
1794
1795   // Attributes section data.
1796   const Attributes_section_data*
1797   attributes_section_data() const
1798   { return this->attributes_section_data_; }
1799
1800  protected:
1801   // Read the symbol information.
1802   void
1803   do_read_symbols(Read_symbols_data* sd);
1804
1805  private:
1806   // processor-specific flags in ELF file header.
1807   elfcpp::Elf_Word processor_specific_flags_;
1808   // Object attributes if there is an .ARM.attributes section or NULL.
1809   Attributes_section_data* attributes_section_data_;
1810 };
1811
1812 // Functor to read reloc addends during stub generation.
1813
1814 template<int sh_type, bool big_endian>
1815 struct Stub_addend_reader
1816 {
1817   // Return the addend for a relocation of a particular type.  Depending
1818   // on whether this is a REL or RELA relocation, read the addend from a
1819   // view or from a Reloc object.
1820   elfcpp::Elf_types<32>::Elf_Swxword
1821   operator()(
1822     unsigned int /* r_type */,
1823     const unsigned char* /* view */,
1824     const typename Reloc_types<sh_type,
1825                                32, big_endian>::Reloc& /* reloc */) const;
1826 };
1827
1828 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1829
1830 template<bool big_endian>
1831 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1832 {
1833   elfcpp::Elf_types<32>::Elf_Swxword
1834   operator()(
1835     unsigned int,
1836     const unsigned char*,
1837     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1838 };
1839
1840 // Specialized Stub_addend_reader for RELA type relocation sections.
1841 // We currently do not handle RELA type relocation sections but it is trivial
1842 // to implement the addend reader.  This is provided for completeness and to
1843 // make it easier to add support for RELA relocation sections in the future.
1844
1845 template<bool big_endian>
1846 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1847 {
1848   elfcpp::Elf_types<32>::Elf_Swxword
1849   operator()(
1850     unsigned int,
1851     const unsigned char*,
1852     const typename Reloc_types<elfcpp::SHT_RELA, 32,
1853                                big_endian>::Reloc& reloc) const
1854   { return reloc.get_r_addend(); }
1855 };
1856
1857 // Cortex_a8_reloc class.  We keep record of relocation that may need
1858 // the Cortex-A8 erratum workaround.
1859
1860 class Cortex_a8_reloc
1861 {
1862  public:
1863   Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1864                   Arm_address destination)
1865     : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1866   { }
1867
1868   ~Cortex_a8_reloc()
1869   { }
1870
1871   // Accessors:  This is a read-only class.
1872
1873   // Return the relocation stub associated with this relocation if there is
1874   // one.
1875   const Reloc_stub*
1876   reloc_stub() const
1877   { return this->reloc_stub_; }
1878
1879   // Return the relocation type.
1880   unsigned int
1881   r_type() const
1882   { return this->r_type_; }
1883
1884   // Return the destination address of the relocation.  LSB stores the THUMB
1885   // bit.
1886   Arm_address
1887   destination() const
1888   { return this->destination_; }
1889
1890  private:
1891   // Associated relocation stub if there is one, or NULL.
1892   const Reloc_stub* reloc_stub_;
1893   // Relocation type.
1894   unsigned int r_type_;
1895   // Destination address of this relocation.  LSB is used to distinguish
1896   // ARM/THUMB mode.
1897   Arm_address destination_;
1898 };
1899
1900 // Arm_output_data_got class.  We derive this from Output_data_got to add
1901 // extra methods to handle TLS relocations in a static link.
1902
1903 template<bool big_endian>
1904 class Arm_output_data_got : public Output_data_got<32, big_endian>
1905 {
1906  public:
1907   Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1908     : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1909   { }
1910
1911   // Add a static entry for the GOT entry at OFFSET.  GSYM is a global
1912   // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1913   // applied in a static link.
1914   void
1915   add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1916   { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1917
1918   // Add a static reloc for the GOT entry at OFFSET.  RELOBJ is an object
1919   // defining a local symbol with INDEX.  R_TYPE is the code of a dynamic
1920   // relocation that needs to be applied in a static link.
1921   void
1922   add_static_reloc(unsigned int got_offset, unsigned int r_type,
1923                    Sized_relobj_file<32, big_endian>* relobj,
1924                    unsigned int index)
1925   {
1926     this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1927                                                 index));
1928   }
1929
1930   // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
1931   // The first one is initialized to be 1, which is the module index for
1932   // the main executable and the second one 0.  A reloc of the type
1933   // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1934   // be applied by gold.  GSYM is a global symbol.
1935   void
1936   add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1937
1938   // Same as the above but for a local symbol in OBJECT with INDEX.
1939   void
1940   add_tls_gd32_with_static_reloc(unsigned int got_type,
1941                                  Sized_relobj_file<32, big_endian>* object,
1942                                  unsigned int index);
1943
1944  protected:
1945   // Write out the GOT table.
1946   void
1947   do_write(Output_file*);
1948
1949  private:
1950   // This class represent dynamic relocations that need to be applied by
1951   // gold because we are using TLS relocations in a static link.
1952   class Static_reloc
1953   {
1954    public:
1955     Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1956       : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1957     { this->u_.global.symbol = gsym; }
1958
1959     Static_reloc(unsigned int got_offset, unsigned int r_type,
1960           Sized_relobj_file<32, big_endian>* relobj, unsigned int index)
1961       : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1962     {
1963       this->u_.local.relobj = relobj;
1964       this->u_.local.index = index;
1965     }
1966
1967     // Return the GOT offset.
1968     unsigned int
1969     got_offset() const
1970     { return this->got_offset_; }
1971
1972     // Relocation type.
1973     unsigned int
1974     r_type() const
1975     { return this->r_type_; }
1976
1977     // Whether the symbol is global or not.
1978     bool
1979     symbol_is_global() const
1980     { return this->symbol_is_global_; }
1981
1982     // For a relocation against a global symbol, the global symbol.
1983     Symbol*
1984     symbol() const
1985     {
1986       gold_assert(this->symbol_is_global_);
1987       return this->u_.global.symbol;
1988     }
1989
1990     // For a relocation against a local symbol, the defining object.
1991     Sized_relobj_file<32, big_endian>*
1992     relobj() const
1993     {
1994       gold_assert(!this->symbol_is_global_);
1995       return this->u_.local.relobj;
1996     }
1997
1998     // For a relocation against a local symbol, the local symbol index.
1999     unsigned int
2000     index() const
2001     {
2002       gold_assert(!this->symbol_is_global_);
2003       return this->u_.local.index;
2004     }
2005
2006    private:
2007     // GOT offset of the entry to which this relocation is applied.
2008     unsigned int got_offset_;
2009     // Type of relocation.
2010     unsigned int r_type_;
2011     // Whether this relocation is against a global symbol.
2012     bool symbol_is_global_;
2013     // A global or local symbol.
2014     union
2015     {
2016       struct
2017       {
2018         // For a global symbol, the symbol itself.
2019         Symbol* symbol;
2020       } global;
2021       struct
2022       {
2023         // For a local symbol, the object defining object.
2024         Sized_relobj_file<32, big_endian>* relobj;
2025         // For a local symbol, the symbol index.
2026         unsigned int index;
2027       } local;
2028     } u_;
2029   };
2030
2031   // Symbol table of the output object.
2032   Symbol_table* symbol_table_;
2033   // Layout of the output object.
2034   Layout* layout_;
2035   // Static relocs to be applied to the GOT.
2036   std::vector<Static_reloc> static_relocs_;
2037 };
2038
2039 // The ARM target has many relocation types with odd-sizes or noncontiguous
2040 // bits.  The default handling of relocatable relocation cannot process these
2041 // relocations.  So we have to extend the default code.
2042
2043 template<bool big_endian, typename Classify_reloc>
2044 class Arm_scan_relocatable_relocs :
2045   public Default_scan_relocatable_relocs<Classify_reloc>
2046 {
2047  public:
2048   // Return the strategy to use for a local symbol which is a section
2049   // symbol, given the relocation type.
2050   inline Relocatable_relocs::Reloc_strategy
2051   local_section_strategy(unsigned int r_type, Relobj*)
2052   {
2053     if (Classify_reloc::sh_type == elfcpp::SHT_RELA)
2054       return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
2055     else
2056       {
2057         if (r_type == elfcpp::R_ARM_TARGET1
2058             || r_type == elfcpp::R_ARM_TARGET2)
2059           {
2060             const Target_arm<big_endian>* arm_target =
2061               Target_arm<big_endian>::default_target();
2062             r_type = arm_target->get_real_reloc_type(r_type);
2063           }
2064
2065         switch(r_type)
2066           {
2067           // Relocations that write nothing.  These exclude R_ARM_TARGET1
2068           // and R_ARM_TARGET2.
2069           case elfcpp::R_ARM_NONE:
2070           case elfcpp::R_ARM_V4BX:
2071           case elfcpp::R_ARM_TLS_GOTDESC:
2072           case elfcpp::R_ARM_TLS_CALL:
2073           case elfcpp::R_ARM_TLS_DESCSEQ:
2074           case elfcpp::R_ARM_THM_TLS_CALL:
2075           case elfcpp::R_ARM_GOTRELAX:
2076           case elfcpp::R_ARM_GNU_VTENTRY:
2077           case elfcpp::R_ARM_GNU_VTINHERIT:
2078           case elfcpp::R_ARM_THM_TLS_DESCSEQ16:
2079           case elfcpp::R_ARM_THM_TLS_DESCSEQ32:
2080             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
2081           // These should have been converted to something else above.
2082           case elfcpp::R_ARM_TARGET1:
2083           case elfcpp::R_ARM_TARGET2:
2084             gold_unreachable();
2085           // Relocations that write full 32 bits and
2086           // have alignment of 1.
2087           case elfcpp::R_ARM_ABS32:
2088           case elfcpp::R_ARM_REL32:
2089           case elfcpp::R_ARM_SBREL32:
2090           case elfcpp::R_ARM_GOTOFF32:
2091           case elfcpp::R_ARM_BASE_PREL:
2092           case elfcpp::R_ARM_GOT_BREL:
2093           case elfcpp::R_ARM_BASE_ABS:
2094           case elfcpp::R_ARM_ABS32_NOI:
2095           case elfcpp::R_ARM_REL32_NOI:
2096           case elfcpp::R_ARM_PLT32_ABS:
2097           case elfcpp::R_ARM_GOT_ABS:
2098           case elfcpp::R_ARM_GOT_PREL:
2099           case elfcpp::R_ARM_TLS_GD32:
2100           case elfcpp::R_ARM_TLS_LDM32:
2101           case elfcpp::R_ARM_TLS_LDO32:
2102           case elfcpp::R_ARM_TLS_IE32:
2103           case elfcpp::R_ARM_TLS_LE32:
2104             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED;
2105           default:
2106             // For all other static relocations, return RELOC_SPECIAL.
2107             return Relocatable_relocs::RELOC_SPECIAL;
2108           }
2109       }
2110   }
2111 };
2112
2113 template<bool big_endian>
2114 class Target_arm : public Sized_target<32, big_endian>
2115 {
2116  public:
2117   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
2118     Reloc_section;
2119
2120   // When were are relocating a stub, we pass this as the relocation number.
2121   static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
2122
2123   Target_arm(const Target::Target_info* info = &arm_info)
2124     : Sized_target<32, big_endian>(info),
2125       got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
2126       rel_dyn_(NULL), rel_irelative_(NULL), copy_relocs_(elfcpp::R_ARM_COPY),
2127       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2128       stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2129       should_force_pic_veneer_(false),
2130       arm_input_section_map_(), attributes_section_data_(NULL),
2131       fix_cortex_a8_(false), cortex_a8_relocs_info_(),
2132       target1_reloc_(elfcpp::R_ARM_ABS32),
2133       // This can be any reloc type but usually is R_ARM_GOT_PREL.
2134       target2_reloc_(elfcpp::R_ARM_GOT_PREL)
2135   { }
2136
2137   // Whether we force PCI branch veneers.
2138   bool
2139   should_force_pic_veneer() const
2140   { return this->should_force_pic_veneer_; }
2141
2142   // Set PIC veneer flag.
2143   void
2144   set_should_force_pic_veneer(bool value)
2145   { this->should_force_pic_veneer_ = value; }
2146
2147   // Whether we use THUMB-2 instructions.
2148   bool
2149   using_thumb2() const
2150   {
2151     Object_attribute* attr =
2152       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2153     int arch = attr->int_value();
2154     return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2155   }
2156
2157   // Whether we use THUMB/THUMB-2 instructions only.
2158   bool
2159   using_thumb_only() const
2160   {
2161     Object_attribute* attr =
2162       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2163
2164     if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M
2165         || attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M)
2166       return true;
2167     if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2168         && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2169       return false;
2170     attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2171     return attr->int_value() == 'M';
2172   }
2173
2174   // Whether we have an NOP instruction.  If not, use mov r0, r0 instead.
2175   bool
2176   may_use_arm_nop() const
2177   {
2178     Object_attribute* attr =
2179       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2180     int arch = attr->int_value();
2181     return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2182             || arch == elfcpp::TAG_CPU_ARCH_V6K
2183             || arch == elfcpp::TAG_CPU_ARCH_V7
2184             || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2185   }
2186
2187   // Whether we have THUMB-2 NOP.W instruction.
2188   bool
2189   may_use_thumb2_nop() const
2190   {
2191     Object_attribute* attr =
2192       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2193     int arch = attr->int_value();
2194     return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2195             || arch == elfcpp::TAG_CPU_ARCH_V7
2196             || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2197   }
2198
2199   // Whether we have v4T interworking instructions available.
2200   bool
2201   may_use_v4t_interworking() const
2202   {
2203     Object_attribute* attr =
2204       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2205     int arch = attr->int_value();
2206     return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2207             && arch != elfcpp::TAG_CPU_ARCH_V4);
2208   }
2209
2210   // Whether we have v5T interworking instructions available.
2211   bool
2212   may_use_v5t_interworking() const
2213   {
2214     Object_attribute* attr =
2215       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2216     int arch = attr->int_value();
2217     if (parameters->options().fix_arm1176())
2218       return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2219               || arch == elfcpp::TAG_CPU_ARCH_V7
2220               || arch == elfcpp::TAG_CPU_ARCH_V6_M
2221               || arch == elfcpp::TAG_CPU_ARCH_V6S_M
2222               || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2223     else
2224       return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2225               && arch != elfcpp::TAG_CPU_ARCH_V4
2226               && arch != elfcpp::TAG_CPU_ARCH_V4T);
2227   }
2228
2229   // Process the relocations to determine unreferenced sections for
2230   // garbage collection.
2231   void
2232   gc_process_relocs(Symbol_table* symtab,
2233                     Layout* layout,
2234                     Sized_relobj_file<32, big_endian>* object,
2235                     unsigned int data_shndx,
2236                     unsigned int sh_type,
2237                     const unsigned char* prelocs,
2238                     size_t reloc_count,
2239                     Output_section* output_section,
2240                     bool needs_special_offset_handling,
2241                     size_t local_symbol_count,
2242                     const unsigned char* plocal_symbols);
2243
2244   // Scan the relocations to look for symbol adjustments.
2245   void
2246   scan_relocs(Symbol_table* symtab,
2247               Layout* layout,
2248               Sized_relobj_file<32, big_endian>* object,
2249               unsigned int data_shndx,
2250               unsigned int sh_type,
2251               const unsigned char* prelocs,
2252               size_t reloc_count,
2253               Output_section* output_section,
2254               bool needs_special_offset_handling,
2255               size_t local_symbol_count,
2256               const unsigned char* plocal_symbols);
2257
2258   // Finalize the sections.
2259   void
2260   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2261
2262   // Return the value to use for a dynamic symbol which requires special
2263   // treatment.
2264   uint64_t
2265   do_dynsym_value(const Symbol*) const;
2266
2267   // Return the plt address for globals. Since we have irelative plt entries,
2268   // address calculation is not as straightforward as plt_address + plt_offset.
2269   uint64_t
2270   do_plt_address_for_global(const Symbol* gsym) const
2271   { return this->plt_section()->address_for_global(gsym); }
2272
2273   // Return the plt address for locals. Since we have irelative plt entries,
2274   // address calculation is not as straightforward as plt_address + plt_offset.
2275   uint64_t
2276   do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
2277   { return this->plt_section()->address_for_local(relobj, symndx); }
2278
2279   // Relocate a section.
2280   void
2281   relocate_section(const Relocate_info<32, big_endian>*,
2282                    unsigned int sh_type,
2283                    const unsigned char* prelocs,
2284                    size_t reloc_count,
2285                    Output_section* output_section,
2286                    bool needs_special_offset_handling,
2287                    unsigned char* view,
2288                    Arm_address view_address,
2289                    section_size_type view_size,
2290                    const Reloc_symbol_changes*);
2291
2292   // Scan the relocs during a relocatable link.
2293   void
2294   scan_relocatable_relocs(Symbol_table* symtab,
2295                           Layout* layout,
2296                           Sized_relobj_file<32, big_endian>* object,
2297                           unsigned int data_shndx,
2298                           unsigned int sh_type,
2299                           const unsigned char* prelocs,
2300                           size_t reloc_count,
2301                           Output_section* output_section,
2302                           bool needs_special_offset_handling,
2303                           size_t local_symbol_count,
2304                           const unsigned char* plocal_symbols,
2305                           Relocatable_relocs*);
2306
2307   // Scan the relocs for --emit-relocs.
2308   void
2309   emit_relocs_scan(Symbol_table* symtab,
2310                    Layout* layout,
2311                    Sized_relobj_file<32, big_endian>* object,
2312                    unsigned int data_shndx,
2313                    unsigned int sh_type,
2314                    const unsigned char* prelocs,
2315                    size_t reloc_count,
2316                    Output_section* output_section,
2317                    bool needs_special_offset_handling,
2318                    size_t local_symbol_count,
2319                    const unsigned char* plocal_syms,
2320                    Relocatable_relocs* rr);
2321
2322   // Emit relocations for a section.
2323   void
2324   relocate_relocs(const Relocate_info<32, big_endian>*,
2325                   unsigned int sh_type,
2326                   const unsigned char* prelocs,
2327                   size_t reloc_count,
2328                   Output_section* output_section,
2329                   typename elfcpp::Elf_types<32>::Elf_Off
2330                     offset_in_output_section,
2331                   unsigned char* view,
2332                   Arm_address view_address,
2333                   section_size_type view_size,
2334                   unsigned char* reloc_view,
2335                   section_size_type reloc_view_size);
2336
2337   // Perform target-specific processing in a relocatable link.  This is
2338   // only used if we use the relocation strategy RELOC_SPECIAL.
2339   void
2340   relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2341                                unsigned int sh_type,
2342                                const unsigned char* preloc_in,
2343                                size_t relnum,
2344                                Output_section* output_section,
2345                                typename elfcpp::Elf_types<32>::Elf_Off
2346                                  offset_in_output_section,
2347                                unsigned char* view,
2348                                typename elfcpp::Elf_types<32>::Elf_Addr
2349                                  view_address,
2350                                section_size_type view_size,
2351                                unsigned char* preloc_out);
2352
2353   // Return whether SYM is defined by the ABI.
2354   bool
2355   do_is_defined_by_abi(const Symbol* sym) const
2356   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2357
2358   // Return whether there is a GOT section.
2359   bool
2360   has_got_section() const
2361   { return this->got_ != NULL; }
2362
2363   // Return the size of the GOT section.
2364   section_size_type
2365   got_size() const
2366   {
2367     gold_assert(this->got_ != NULL);
2368     return this->got_->data_size();
2369   }
2370
2371   // Return the number of entries in the GOT.
2372   unsigned int
2373   got_entry_count() const
2374   {
2375     if (!this->has_got_section())
2376       return 0;
2377     return this->got_size() / 4;
2378   }
2379
2380   // Return the number of entries in the PLT.
2381   unsigned int
2382   plt_entry_count() const;
2383
2384   // Return the offset of the first non-reserved PLT entry.
2385   unsigned int
2386   first_plt_entry_offset() const;
2387
2388   // Return the size of each PLT entry.
2389   unsigned int
2390   plt_entry_size() const;
2391
2392   // Get the section to use for IRELATIVE relocations, create it if necessary.
2393   Reloc_section*
2394   rel_irelative_section(Layout*);
2395
2396   // Map platform-specific reloc types
2397   unsigned int
2398   get_real_reloc_type(unsigned int r_type) const;
2399
2400   //
2401   // Methods to support stub-generations.
2402   //
2403
2404   // Return the stub factory
2405   const Stub_factory&
2406   stub_factory() const
2407   { return this->stub_factory_; }
2408
2409   // Make a new Arm_input_section object.
2410   Arm_input_section<big_endian>*
2411   new_arm_input_section(Relobj*, unsigned int);
2412
2413   // Find the Arm_input_section object corresponding to the SHNDX-th input
2414   // section of RELOBJ.
2415   Arm_input_section<big_endian>*
2416   find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2417
2418   // Make a new Stub_table
2419   Stub_table<big_endian>*
2420   new_stub_table(Arm_input_section<big_endian>*);
2421
2422   // Scan a section for stub generation.
2423   void
2424   scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2425                          const unsigned char*, size_t, Output_section*,
2426                          bool, const unsigned char*, Arm_address,
2427                          section_size_type);
2428
2429   // Relocate a stub.
2430   void
2431   relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2432                 Output_section*, unsigned char*, Arm_address,
2433                 section_size_type);
2434
2435   // Get the default ARM target.
2436   static Target_arm<big_endian>*
2437   default_target()
2438   {
2439     gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2440                 && parameters->target().is_big_endian() == big_endian);
2441     return static_cast<Target_arm<big_endian>*>(
2442              parameters->sized_target<32, big_endian>());
2443   }
2444
2445   // Whether NAME belongs to a mapping symbol.
2446   static bool
2447   is_mapping_symbol_name(const char* name)
2448   {
2449     return (name
2450             && name[0] == '$'
2451             && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2452             && (name[2] == '\0' || name[2] == '.'));
2453   }
2454
2455   // Whether we work around the Cortex-A8 erratum.
2456   bool
2457   fix_cortex_a8() const
2458   { return this->fix_cortex_a8_; }
2459
2460   // Whether we merge exidx entries in debuginfo.
2461   bool
2462   merge_exidx_entries() const
2463   { return parameters->options().merge_exidx_entries(); }
2464
2465   // Whether we fix R_ARM_V4BX relocation.
2466   // 0 - do not fix
2467   // 1 - replace with MOV instruction (armv4 target)
2468   // 2 - make interworking veneer (>= armv4t targets only)
2469   General_options::Fix_v4bx
2470   fix_v4bx() const
2471   { return parameters->options().fix_v4bx(); }
2472
2473   // Scan a span of THUMB code section for Cortex-A8 erratum.
2474   void
2475   scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2476                                   section_size_type, section_size_type,
2477                                   const unsigned char*, Arm_address);
2478
2479   // Apply Cortex-A8 workaround to a branch.
2480   void
2481   apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2482                              unsigned char*, Arm_address);
2483
2484  protected:
2485   // Make the PLT-generator object.
2486   Output_data_plt_arm<big_endian>*
2487   make_data_plt(Layout* layout,
2488                 Arm_output_data_got<big_endian>* got,
2489                 Output_data_space* got_plt,
2490                 Output_data_space* got_irelative)
2491   { return this->do_make_data_plt(layout, got, got_plt, got_irelative); }
2492
2493   // Make an ELF object.
2494   Object*
2495   do_make_elf_object(const std::string&, Input_file*, off_t,
2496                      const elfcpp::Ehdr<32, big_endian>& ehdr);
2497
2498   Object*
2499   do_make_elf_object(const std::string&, Input_file*, off_t,
2500                      const elfcpp::Ehdr<32, !big_endian>&)
2501   { gold_unreachable(); }
2502
2503   Object*
2504   do_make_elf_object(const std::string&, Input_file*, off_t,
2505                       const elfcpp::Ehdr<64, false>&)
2506   { gold_unreachable(); }
2507
2508   Object*
2509   do_make_elf_object(const std::string&, Input_file*, off_t,
2510                      const elfcpp::Ehdr<64, true>&)
2511   { gold_unreachable(); }
2512
2513   // Make an output section.
2514   Output_section*
2515   do_make_output_section(const char* name, elfcpp::Elf_Word type,
2516                          elfcpp::Elf_Xword flags)
2517   { return new Arm_output_section<big_endian>(name, type, flags); }
2518
2519   void
2520   do_adjust_elf_header(unsigned char* view, int len);
2521
2522   // We only need to generate stubs, and hence perform relaxation if we are
2523   // not doing relocatable linking.
2524   bool
2525   do_may_relax() const
2526   { return !parameters->options().relocatable(); }
2527
2528   bool
2529   do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
2530
2531   // Determine whether an object attribute tag takes an integer, a
2532   // string or both.
2533   int
2534   do_attribute_arg_type(int tag) const;
2535
2536   // Reorder tags during output.
2537   int
2538   do_attributes_order(int num) const;
2539
2540   // This is called when the target is selected as the default.
2541   void
2542   do_select_as_default_target()
2543   {
2544     // No locking is required since there should only be one default target.
2545     // We cannot have both the big-endian and little-endian ARM targets
2546     // as the default.
2547     gold_assert(arm_reloc_property_table == NULL);
2548     arm_reloc_property_table = new Arm_reloc_property_table();
2549     if (parameters->options().user_set_target1_rel())
2550       {
2551         // FIXME: This is not strictly compatible with ld, which allows both
2552         // --target1-abs and --target-rel to be given.
2553         if (parameters->options().user_set_target1_abs())
2554           gold_error(_("Cannot use both --target1-abs and --target1-rel."));
2555         else
2556           this->target1_reloc_ = elfcpp::R_ARM_REL32;
2557       }
2558     // We don't need to handle --target1-abs because target1_reloc_ is set
2559     // to elfcpp::R_ARM_ABS32 in the member initializer list.
2560
2561     if (parameters->options().user_set_target2())
2562       {
2563         const char* target2 = parameters->options().target2();
2564         if (strcmp(target2, "rel") == 0)
2565           this->target2_reloc_ = elfcpp::R_ARM_REL32;
2566         else if (strcmp(target2, "abs") == 0)
2567           this->target2_reloc_ = elfcpp::R_ARM_ABS32;
2568         else if (strcmp(target2, "got-rel") == 0)
2569           this->target2_reloc_ = elfcpp::R_ARM_GOT_PREL;
2570         else
2571           gold_unreachable();
2572       }
2573   }
2574
2575   // Virtual function which is set to return true by a target if
2576   // it can use relocation types to determine if a function's
2577   // pointer is taken.
2578   virtual bool
2579   do_can_check_for_function_pointers() const
2580   { return true; }
2581
2582   // Whether a section called SECTION_NAME may have function pointers to
2583   // sections not eligible for safe ICF folding.
2584   virtual bool
2585   do_section_may_have_icf_unsafe_pointers(const char* section_name) const
2586   {
2587     return (!is_prefix_of(".ARM.exidx", section_name)
2588             && !is_prefix_of(".ARM.extab", section_name)
2589             && Target::do_section_may_have_icf_unsafe_pointers(section_name));
2590   }
2591
2592   virtual void
2593   do_define_standard_symbols(Symbol_table*, Layout*);
2594
2595   virtual Output_data_plt_arm<big_endian>*
2596   do_make_data_plt(Layout* layout,
2597                    Arm_output_data_got<big_endian>* got,
2598                    Output_data_space* got_plt,
2599                    Output_data_space* got_irelative)
2600   {
2601     gold_assert(got_plt != NULL && got_irelative != NULL);
2602     if (parameters->options().long_plt())
2603       return new Output_data_plt_arm_long<big_endian>(
2604         layout, got, got_plt, got_irelative);
2605     else
2606       return new Output_data_plt_arm_short<big_endian>(
2607         layout, got, got_plt, got_irelative);
2608   }
2609
2610  private:
2611   // The class which scans relocations.
2612   class Scan
2613   {
2614    public:
2615     Scan()
2616       : issued_non_pic_error_(false)
2617     { }
2618
2619     static inline int
2620     get_reference_flags(unsigned int r_type);
2621
2622     inline void
2623     local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2624           Sized_relobj_file<32, big_endian>* object,
2625           unsigned int data_shndx,
2626           Output_section* output_section,
2627           const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2628           const elfcpp::Sym<32, big_endian>& lsym,
2629           bool is_discarded);
2630
2631     inline void
2632     global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2633            Sized_relobj_file<32, big_endian>* object,
2634            unsigned int data_shndx,
2635            Output_section* output_section,
2636            const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2637            Symbol* gsym);
2638
2639     inline bool
2640     local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2641                                         Sized_relobj_file<32, big_endian>* ,
2642                                         unsigned int ,
2643                                         Output_section* ,
2644                                         const elfcpp::Rel<32, big_endian>& ,
2645                                         unsigned int ,
2646                                         const elfcpp::Sym<32, big_endian>&);
2647
2648     inline bool
2649     global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2650                                          Sized_relobj_file<32, big_endian>* ,
2651                                          unsigned int ,
2652                                          Output_section* ,
2653                                          const elfcpp::Rel<32, big_endian>& ,
2654                                          unsigned int , Symbol*);
2655
2656    private:
2657     static void
2658     unsupported_reloc_local(Sized_relobj_file<32, big_endian>*,
2659                             unsigned int r_type);
2660
2661     static void
2662     unsupported_reloc_global(Sized_relobj_file<32, big_endian>*,
2663                              unsigned int r_type, Symbol*);
2664
2665     void
2666     check_non_pic(Relobj*, unsigned int r_type);
2667
2668     // Almost identical to Symbol::needs_plt_entry except that it also
2669     // handles STT_ARM_TFUNC.
2670     static bool
2671     symbol_needs_plt_entry(const Symbol* sym)
2672     {
2673       // An undefined symbol from an executable does not need a PLT entry.
2674       if (sym->is_undefined() && !parameters->options().shared())
2675         return false;
2676
2677       if (sym->type() == elfcpp::STT_GNU_IFUNC)
2678         return true;
2679
2680       return (!parameters->doing_static_link()
2681               && (sym->type() == elfcpp::STT_FUNC
2682                   || sym->type() == elfcpp::STT_ARM_TFUNC)
2683               && (sym->is_from_dynobj()
2684                   || sym->is_undefined()
2685                   || sym->is_preemptible()));
2686     }
2687
2688     inline bool
2689     possible_function_pointer_reloc(unsigned int r_type);
2690
2691     // Whether a plt entry is needed for ifunc.
2692     bool
2693     reloc_needs_plt_for_ifunc(Sized_relobj_file<32, big_endian>*,
2694                               unsigned int r_type);
2695
2696     // Whether we have issued an error about a non-PIC compilation.
2697     bool issued_non_pic_error_;
2698   };
2699
2700   // The class which implements relocation.
2701   class Relocate
2702   {
2703    public:
2704     Relocate()
2705     { }
2706
2707     ~Relocate()
2708     { }
2709
2710     // Return whether the static relocation needs to be applied.
2711     inline bool
2712     should_apply_static_reloc(const Sized_symbol<32>* gsym,
2713                               unsigned int r_type,
2714                               bool is_32bit,
2715                               Output_section* output_section);
2716
2717     // Do a relocation.  Return false if the caller should not issue
2718     // any warnings about this relocation.
2719     inline bool
2720     relocate(const Relocate_info<32, big_endian>*, unsigned int,
2721              Target_arm*, Output_section*, size_t, const unsigned char*,
2722              const Sized_symbol<32>*, const Symbol_value<32>*,
2723              unsigned char*, Arm_address, section_size_type);
2724
2725     // Return whether we want to pass flag NON_PIC_REF for this
2726     // reloc.  This means the relocation type accesses a symbol not via
2727     // GOT or PLT.
2728     static inline bool
2729     reloc_is_non_pic(unsigned int r_type)
2730     {
2731       switch (r_type)
2732         {
2733         // These relocation types reference GOT or PLT entries explicitly.
2734         case elfcpp::R_ARM_GOT_BREL:
2735         case elfcpp::R_ARM_GOT_ABS:
2736         case elfcpp::R_ARM_GOT_PREL:
2737         case elfcpp::R_ARM_GOT_BREL12:
2738         case elfcpp::R_ARM_PLT32_ABS:
2739         case elfcpp::R_ARM_TLS_GD32:
2740         case elfcpp::R_ARM_TLS_LDM32:
2741         case elfcpp::R_ARM_TLS_IE32:
2742         case elfcpp::R_ARM_TLS_IE12GP:
2743
2744         // These relocate types may use PLT entries.
2745         case elfcpp::R_ARM_CALL:
2746         case elfcpp::R_ARM_THM_CALL:
2747         case elfcpp::R_ARM_JUMP24:
2748         case elfcpp::R_ARM_THM_JUMP24:
2749         case elfcpp::R_ARM_THM_JUMP19:
2750         case elfcpp::R_ARM_PLT32:
2751         case elfcpp::R_ARM_THM_XPC22:
2752         case elfcpp::R_ARM_PREL31:
2753         case elfcpp::R_ARM_SBREL31:
2754           return false;
2755
2756         default:
2757           return true;
2758         }
2759     }
2760
2761    private:
2762     // Do a TLS relocation.
2763     inline typename Arm_relocate_functions<big_endian>::Status
2764     relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2765                  size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2766                  const Sized_symbol<32>*, const Symbol_value<32>*,
2767                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2768                  section_size_type);
2769
2770   };
2771
2772   // A class for inquiring about properties of a relocation,
2773   // used while scanning relocs during a relocatable link and
2774   // garbage collection.
2775   class Classify_reloc :
2776       public gold::Default_classify_reloc<elfcpp::SHT_REL, 32, big_endian>
2777   {
2778    public:
2779     typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc
2780         Reltype;
2781
2782     // Return the explicit addend of the relocation (return 0 for SHT_REL).
2783     static typename elfcpp::Elf_types<32>::Elf_Swxword
2784     get_r_addend(const Reltype*)
2785     { return 0; }
2786
2787     // Return the size of the addend of the relocation (only used for SHT_REL).
2788     static unsigned int
2789     get_size_for_reloc(unsigned int, Relobj*);
2790   };
2791
2792   // Adjust TLS relocation type based on the options and whether this
2793   // is a local symbol.
2794   static tls::Tls_optimization
2795   optimize_tls_reloc(bool is_final, int r_type);
2796
2797   // Get the GOT section, creating it if necessary.
2798   Arm_output_data_got<big_endian>*
2799   got_section(Symbol_table*, Layout*);
2800
2801   // Get the GOT PLT section.
2802   Output_data_space*
2803   got_plt_section() const
2804   {
2805     gold_assert(this->got_plt_ != NULL);
2806     return this->got_plt_;
2807   }
2808
2809   // Create the PLT section.
2810   void
2811   make_plt_section(Symbol_table* symtab, Layout* layout);
2812
2813   // Create a PLT entry for a global symbol.
2814   void
2815   make_plt_entry(Symbol_table*, Layout*, Symbol*);
2816
2817   // Create a PLT entry for a local STT_GNU_IFUNC symbol.
2818   void
2819   make_local_ifunc_plt_entry(Symbol_table*, Layout*,
2820                              Sized_relobj_file<32, big_endian>* relobj,
2821                              unsigned int local_sym_index);
2822
2823   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2824   void
2825   define_tls_base_symbol(Symbol_table*, Layout*);
2826
2827   // Create a GOT entry for the TLS module index.
2828   unsigned int
2829   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2830                       Sized_relobj_file<32, big_endian>* object);
2831
2832   // Get the PLT section.
2833   const Output_data_plt_arm<big_endian>*
2834   plt_section() const
2835   {
2836     gold_assert(this->plt_ != NULL);
2837     return this->plt_;
2838   }
2839
2840   // Get the dynamic reloc section, creating it if necessary.
2841   Reloc_section*
2842   rel_dyn_section(Layout*);
2843
2844   // Get the section to use for TLS_DESC relocations.
2845   Reloc_section*
2846   rel_tls_desc_section(Layout*) const;
2847
2848   // Return true if the symbol may need a COPY relocation.
2849   // References from an executable object to non-function symbols
2850   // defined in a dynamic object may need a COPY relocation.
2851   bool
2852   may_need_copy_reloc(Symbol* gsym)
2853   {
2854     return (gsym->type() != elfcpp::STT_ARM_TFUNC
2855             && gsym->may_need_copy_reloc());
2856   }
2857
2858   // Add a potential copy relocation.
2859   void
2860   copy_reloc(Symbol_table* symtab, Layout* layout,
2861              Sized_relobj_file<32, big_endian>* object,
2862              unsigned int shndx, Output_section* output_section,
2863              Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2864   {
2865     unsigned int r_type = elfcpp::elf_r_type<32>(reloc.get_r_info());
2866     this->copy_relocs_.copy_reloc(symtab, layout,
2867                                   symtab->get_sized_symbol<32>(sym),
2868                                   object, shndx, output_section,
2869                                   r_type, reloc.get_r_offset(), 0,
2870                                   this->rel_dyn_section(layout));
2871   }
2872
2873   // Whether two EABI versions are compatible.
2874   static bool
2875   are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2876
2877   // Merge processor-specific flags from input object and those in the ELF
2878   // header of the output.
2879   void
2880   merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2881
2882   // Get the secondary compatible architecture.
2883   static int
2884   get_secondary_compatible_arch(const Attributes_section_data*);
2885
2886   // Set the secondary compatible architecture.
2887   static void
2888   set_secondary_compatible_arch(Attributes_section_data*, int);
2889
2890   static int
2891   tag_cpu_arch_combine(const char*, int, int*, int, int);
2892
2893   // Helper to print AEABI enum tag value.
2894   static std::string
2895   aeabi_enum_name(unsigned int);
2896
2897   // Return string value for TAG_CPU_name.
2898   static std::string
2899   tag_cpu_name_value(unsigned int);
2900
2901   // Query attributes object to see if integer divide instructions may be
2902   // present in an object.
2903   static bool
2904   attributes_accept_div(int arch, int profile,
2905                         const Object_attribute* div_attr);
2906
2907   // Query attributes object to see if integer divide instructions are
2908   // forbidden to be in the object.  This is not the inverse of
2909   // attributes_accept_div.
2910   static bool
2911   attributes_forbid_div(const Object_attribute* div_attr);
2912
2913   // Merge object attributes from input object and those in the output.
2914   void
2915   merge_object_attributes(const char*, const Attributes_section_data*);
2916
2917   // Helper to get an AEABI object attribute
2918   Object_attribute*
2919   get_aeabi_object_attribute(int tag) const
2920   {
2921     Attributes_section_data* pasd = this->attributes_section_data_;
2922     gold_assert(pasd != NULL);
2923     Object_attribute* attr =
2924       pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2925     gold_assert(attr != NULL);
2926     return attr;
2927   }
2928
2929   //
2930   // Methods to support stub-generations.
2931   //
2932
2933   // Group input sections for stub generation.
2934   void
2935   group_sections(Layout*, section_size_type, bool, const Task*);
2936
2937   // Scan a relocation for stub generation.
2938   void
2939   scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2940                       const Sized_symbol<32>*, unsigned int,
2941                       const Symbol_value<32>*,
2942                       elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2943
2944   // Scan a relocation section for stub.
2945   template<int sh_type>
2946   void
2947   scan_reloc_section_for_stubs(
2948       const Relocate_info<32, big_endian>* relinfo,
2949       const unsigned char* prelocs,
2950       size_t reloc_count,
2951       Output_section* output_section,
2952       bool needs_special_offset_handling,
2953       const unsigned char* view,
2954       elfcpp::Elf_types<32>::Elf_Addr view_address,
2955       section_size_type);
2956
2957   // Fix .ARM.exidx section coverage.
2958   void
2959   fix_exidx_coverage(Layout*, const Input_objects*,
2960                      Arm_output_section<big_endian>*, Symbol_table*,
2961                      const Task*);
2962
2963   // Functors for STL set.
2964   struct output_section_address_less_than
2965   {
2966     bool
2967     operator()(const Output_section* s1, const Output_section* s2) const
2968     { return s1->address() < s2->address(); }
2969   };
2970
2971   // Information about this specific target which we pass to the
2972   // general Target structure.
2973   static const Target::Target_info arm_info;
2974
2975   // The types of GOT entries needed for this platform.
2976   // These values are exposed to the ABI in an incremental link.
2977   // Do not renumber existing values without changing the version
2978   // number of the .gnu_incremental_inputs section.
2979   enum Got_type
2980   {
2981     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
2982     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
2983     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
2984     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
2985     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
2986   };
2987
2988   typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2989
2990   // Map input section to Arm_input_section.
2991   typedef Unordered_map<Section_id,
2992                         Arm_input_section<big_endian>*,
2993                         Section_id_hash>
2994           Arm_input_section_map;
2995
2996   // Map output addresses to relocs for Cortex-A8 erratum.
2997   typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2998           Cortex_a8_relocs_info;
2999
3000   // The GOT section.
3001   Arm_output_data_got<big_endian>* got_;
3002   // The PLT section.
3003   Output_data_plt_arm<big_endian>* plt_;
3004   // The GOT PLT section.
3005   Output_data_space* got_plt_;
3006   // The GOT section for IRELATIVE relocations.
3007   Output_data_space* got_irelative_;
3008   // The dynamic reloc section.
3009   Reloc_section* rel_dyn_;
3010   // The section to use for IRELATIVE relocs.
3011   Reloc_section* rel_irelative_;
3012   // Relocs saved to avoid a COPY reloc.
3013   Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
3014   // Offset of the GOT entry for the TLS module index.
3015   unsigned int got_mod_index_offset_;
3016   // True if the _TLS_MODULE_BASE_ symbol has been defined.
3017   bool tls_base_symbol_defined_;
3018   // Vector of Stub_tables created.
3019   Stub_table_list stub_tables_;
3020   // Stub factory.
3021   const Stub_factory &stub_factory_;
3022   // Whether we force PIC branch veneers.
3023   bool should_force_pic_veneer_;
3024   // Map for locating Arm_input_sections.
3025   Arm_input_section_map arm_input_section_map_;
3026   // Attributes section data in output.
3027   Attributes_section_data* attributes_section_data_;
3028   // Whether we want to fix code for Cortex-A8 erratum.
3029   bool fix_cortex_a8_;
3030   // Map addresses to relocs for Cortex-A8 erratum.
3031   Cortex_a8_relocs_info cortex_a8_relocs_info_;
3032   // What R_ARM_TARGET1 maps to. It can be R_ARM_REL32 or R_ARM_ABS32.
3033   unsigned int target1_reloc_;
3034   // What R_ARM_TARGET2 maps to. It should be one of R_ARM_REL32, R_ARM_ABS32
3035   // and R_ARM_GOT_PREL.
3036   unsigned int target2_reloc_;
3037 };
3038
3039 template<bool big_endian>
3040 const Target::Target_info Target_arm<big_endian>::arm_info =
3041 {
3042   32,                   // size
3043   big_endian,           // is_big_endian
3044   elfcpp::EM_ARM,       // machine_code
3045   false,                // has_make_symbol
3046   false,                // has_resolve
3047   false,                // has_code_fill
3048   true,                 // is_default_stack_executable
3049   false,                // can_icf_inline_merge_sections
3050   '\0',                 // wrap_char
3051   "/usr/lib/libc.so.1", // dynamic_linker
3052   0x8000,               // default_text_segment_address
3053   0x1000,               // abi_pagesize (overridable by -z max-page-size)
3054   0x1000,               // common_pagesize (overridable by -z common-page-size)
3055   false,                // isolate_execinstr
3056   0,                    // rosegment_gap
3057   elfcpp::SHN_UNDEF,    // small_common_shndx
3058   elfcpp::SHN_UNDEF,    // large_common_shndx
3059   0,                    // small_common_section_flags
3060   0,                    // large_common_section_flags
3061   ".ARM.attributes",    // attributes_section
3062   "aeabi",              // attributes_vendor
3063   "_start",             // entry_symbol_name
3064   32,                   // hash_entry_size
3065 };
3066
3067 // Arm relocate functions class
3068 //
3069
3070 template<bool big_endian>
3071 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
3072 {
3073  public:
3074   typedef enum
3075   {
3076     STATUS_OKAY,        // No error during relocation.
3077     STATUS_OVERFLOW,    // Relocation overflow.
3078     STATUS_BAD_RELOC    // Relocation cannot be applied.
3079   } Status;
3080
3081  private:
3082   typedef Relocate_functions<32, big_endian> Base;
3083   typedef Arm_relocate_functions<big_endian> This;
3084
3085   // Encoding of imm16 argument for movt and movw ARM instructions
3086   // from ARM ARM:
3087   //
3088   //     imm16 := imm4 | imm12
3089   //
3090   //  f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0
3091   // +-------+---------------+-------+-------+-----------------------+
3092   // |       |               |imm4   |       |imm12                  |
3093   // +-------+---------------+-------+-------+-----------------------+
3094
3095   // Extract the relocation addend from VAL based on the ARM
3096   // instruction encoding described above.
3097   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3098   extract_arm_movw_movt_addend(
3099       typename elfcpp::Swap<32, big_endian>::Valtype val)
3100   {
3101     // According to the Elf ABI for ARM Architecture the immediate
3102     // field is sign-extended to form the addend.
3103     return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff));
3104   }
3105
3106   // Insert X into VAL based on the ARM instruction encoding described
3107   // above.
3108   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3109   insert_val_arm_movw_movt(
3110       typename elfcpp::Swap<32, big_endian>::Valtype val,
3111       typename elfcpp::Swap<32, big_endian>::Valtype x)
3112   {
3113     val &= 0xfff0f000;
3114     val |= x & 0x0fff;
3115     val |= (x & 0xf000) << 4;
3116     return val;
3117   }
3118
3119   // Encoding of imm16 argument for movt and movw Thumb2 instructions
3120   // from ARM ARM:
3121   //
3122   //     imm16 := imm4 | i | imm3 | imm8
3123   //
3124   //  f e d c b a 9 8 7 6 5 4 3 2 1 0  f e d c b a 9 8 7 6 5 4 3 2 1 0
3125   // +---------+-+-----------+-------++-+-----+-------+---------------+
3126   // |         |i|           |imm4   || |imm3 |       |imm8           |
3127   // +---------+-+-----------+-------++-+-----+-------+---------------+
3128
3129   // Extract the relocation addend from VAL based on the Thumb2
3130   // instruction encoding described above.
3131   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3132   extract_thumb_movw_movt_addend(
3133       typename elfcpp::Swap<32, big_endian>::Valtype val)
3134   {
3135     // According to the Elf ABI for ARM Architecture the immediate
3136     // field is sign-extended to form the addend.
3137     return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
3138                                    | ((val >> 15) & 0x0800)
3139                                    | ((val >> 4) & 0x0700)
3140                                    | (val & 0x00ff));
3141   }
3142
3143   // Insert X into VAL based on the Thumb2 instruction encoding
3144   // described above.
3145   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3146   insert_val_thumb_movw_movt(
3147       typename elfcpp::Swap<32, big_endian>::Valtype val,
3148       typename elfcpp::Swap<32, big_endian>::Valtype x)
3149   {
3150     val &= 0xfbf08f00;
3151     val |= (x & 0xf000) << 4;
3152     val |= (x & 0x0800) << 15;
3153     val |= (x & 0x0700) << 4;
3154     val |= (x & 0x00ff);
3155     return val;
3156   }
3157
3158   // Calculate the smallest constant Kn for the specified residual.
3159   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3160   static uint32_t
3161   calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3162   {
3163     int32_t msb;
3164
3165     if (residual == 0)
3166       return 0;
3167     // Determine the most significant bit in the residual and
3168     // align the resulting value to a 2-bit boundary.
3169     for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3170       ;
3171     // The desired shift is now (msb - 6), or zero, whichever
3172     // is the greater.
3173     return (((msb - 6) < 0) ? 0 : (msb - 6));
3174   }
3175
3176   // Calculate the final residual for the specified group index.
3177   // If the passed group index is less than zero, the method will return
3178   // the value of the specified residual without any change.
3179   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3180   static typename elfcpp::Swap<32, big_endian>::Valtype
3181   calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3182                     const int group)
3183   {
3184     for (int n = 0; n <= group; n++)
3185       {
3186         // Calculate which part of the value to mask.
3187         uint32_t shift = calc_grp_kn(residual);
3188         // Calculate the residual for the next time around.
3189         residual &= ~(residual & (0xff << shift));
3190       }
3191
3192     return residual;
3193   }
3194
3195   // Calculate the value of Gn for the specified group index.
3196   // We return it in the form of an encoded constant-and-rotation.
3197   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3198   static typename elfcpp::Swap<32, big_endian>::Valtype
3199   calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3200               const int group)
3201   {
3202     typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3203     uint32_t shift = 0;
3204
3205     for (int n = 0; n <= group; n++)
3206       {
3207         // Calculate which part of the value to mask.
3208         shift = calc_grp_kn(residual);
3209         // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3210         gn = residual & (0xff << shift);
3211         // Calculate the residual for the next time around.
3212         residual &= ~gn;
3213       }
3214     // Return Gn in the form of an encoded constant-and-rotation.
3215     return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3216   }
3217
3218  public:
3219   // Handle ARM long branches.
3220   static typename This::Status
3221   arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3222                     unsigned char*, const Sized_symbol<32>*,
3223                     const Arm_relobj<big_endian>*, unsigned int,
3224                     const Symbol_value<32>*, Arm_address, Arm_address, bool);
3225
3226   // Handle THUMB long branches.
3227   static typename This::Status
3228   thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3229                       unsigned char*, const Sized_symbol<32>*,
3230                       const Arm_relobj<big_endian>*, unsigned int,
3231                       const Symbol_value<32>*, Arm_address, Arm_address, bool);
3232
3233
3234   // Return the branch offset of a 32-bit THUMB branch.
3235   static inline int32_t
3236   thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3237   {
3238     // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3239     // involving the J1 and J2 bits.
3240     uint32_t s = (upper_insn & (1U << 10)) >> 10;
3241     uint32_t upper = upper_insn & 0x3ffU;
3242     uint32_t lower = lower_insn & 0x7ffU;
3243     uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3244     uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3245     uint32_t i1 = j1 ^ s ? 0 : 1;
3246     uint32_t i2 = j2 ^ s ? 0 : 1;
3247
3248     return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3249                                    | (upper << 12) | (lower << 1));
3250   }
3251
3252   // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3253   // UPPER_INSN is the original upper instruction of the branch.  Caller is
3254   // responsible for overflow checking and BLX offset adjustment.
3255   static inline uint16_t
3256   thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3257   {
3258     uint32_t s = offset < 0 ? 1 : 0;
3259     uint32_t bits = static_cast<uint32_t>(offset);
3260     return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3261   }
3262
3263   // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3264   // LOWER_INSN is the original lower instruction of the branch.  Caller is
3265   // responsible for overflow checking and BLX offset adjustment.
3266   static inline uint16_t
3267   thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3268   {
3269     uint32_t s = offset < 0 ? 1 : 0;
3270     uint32_t bits = static_cast<uint32_t>(offset);
3271     return ((lower_insn & ~0x2fffU)
3272             | ((((bits >> 23) & 1) ^ !s) << 13)
3273             | ((((bits >> 22) & 1) ^ !s) << 11)
3274             | ((bits >> 1) & 0x7ffU));
3275   }
3276
3277   // Return the branch offset of a 32-bit THUMB conditional branch.
3278   static inline int32_t
3279   thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3280   {
3281     uint32_t s = (upper_insn & 0x0400U) >> 10;
3282     uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3283     uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3284     uint32_t lower = (lower_insn & 0x07ffU);
3285     uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3286
3287     return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3288   }
3289
3290   // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3291   // instruction.  UPPER_INSN is the original upper instruction of the branch.
3292   // Caller is responsible for overflow checking.
3293   static inline uint16_t
3294   thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3295   {
3296     uint32_t s = offset < 0 ? 1 : 0;
3297     uint32_t bits = static_cast<uint32_t>(offset);
3298     return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3299   }
3300
3301   // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3302   // instruction.  LOWER_INSN is the original lower instruction of the branch.
3303   // The caller is responsible for overflow checking.
3304   static inline uint16_t
3305   thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3306   {
3307     uint32_t bits = static_cast<uint32_t>(offset);
3308     uint32_t j2 = (bits & 0x00080000U) >> 19;
3309     uint32_t j1 = (bits & 0x00040000U) >> 18;
3310     uint32_t lo = (bits & 0x00000ffeU) >> 1;
3311
3312     return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3313   }
3314
3315   // R_ARM_ABS8: S + A
3316   static inline typename This::Status
3317   abs8(unsigned char* view,
3318        const Sized_relobj_file<32, big_endian>* object,
3319        const Symbol_value<32>* psymval)
3320   {
3321     typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3322     Valtype* wv = reinterpret_cast<Valtype*>(view);
3323     Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3324     int32_t addend = Bits<8>::sign_extend32(val);
3325     Arm_address x = psymval->value(object, addend);
3326     val = Bits<32>::bit_select32(val, x, 0xffU);
3327     elfcpp::Swap<8, big_endian>::writeval(wv, val);
3328
3329     // R_ARM_ABS8 permits signed or unsigned results.
3330     return (Bits<8>::has_signed_unsigned_overflow32(x)
3331             ? This::STATUS_OVERFLOW
3332             : This::STATUS_OKAY);
3333   }
3334
3335   // R_ARM_THM_ABS5: S + A
3336   static inline typename This::Status
3337   thm_abs5(unsigned char* view,
3338        const Sized_relobj_file<32, big_endian>* object,
3339        const Symbol_value<32>* psymval)
3340   {
3341     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3342     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3343     Valtype* wv = reinterpret_cast<Valtype*>(view);
3344     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3345     Reltype addend = (val & 0x7e0U) >> 6;
3346     Reltype x = psymval->value(object, addend);
3347     val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3348     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3349     return (Bits<5>::has_overflow32(x)
3350             ? This::STATUS_OVERFLOW
3351             : This::STATUS_OKAY);
3352   }
3353
3354   // R_ARM_ABS12: S + A
3355   static inline typename This::Status
3356   abs12(unsigned char* view,
3357         const Sized_relobj_file<32, big_endian>* object,
3358         const Symbol_value<32>* psymval)
3359   {
3360     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3361     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3362     Valtype* wv = reinterpret_cast<Valtype*>(view);
3363     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3364     Reltype addend = val & 0x0fffU;
3365     Reltype x = psymval->value(object, addend);
3366     val = Bits<32>::bit_select32(val, x, 0x0fffU);
3367     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3368     return (Bits<12>::has_overflow32(x)
3369             ? This::STATUS_OVERFLOW
3370             : This::STATUS_OKAY);
3371   }
3372
3373   // R_ARM_ABS16: S + A
3374   static inline typename This::Status
3375   abs16(unsigned char* view,
3376         const Sized_relobj_file<32, big_endian>* object,
3377         const Symbol_value<32>* psymval)
3378   {
3379     typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
3380     Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view);
3381     int32_t addend = Bits<16>::sign_extend32(val);
3382     Arm_address x = psymval->value(object, addend);
3383     val = Bits<32>::bit_select32(val, x, 0xffffU);
3384     elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val);
3385
3386     // R_ARM_ABS16 permits signed or unsigned results.
3387     return (Bits<16>::has_signed_unsigned_overflow32(x)
3388             ? This::STATUS_OVERFLOW
3389             : This::STATUS_OKAY);
3390   }
3391
3392   // R_ARM_ABS32: (S + A) | T
3393   static inline typename This::Status
3394   abs32(unsigned char* view,
3395         const Sized_relobj_file<32, big_endian>* object,
3396         const Symbol_value<32>* psymval,
3397         Arm_address thumb_bit)
3398   {
3399     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3400     Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3401     Valtype x = psymval->value(object, addend) | thumb_bit;
3402     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3403     return This::STATUS_OKAY;
3404   }
3405
3406   // R_ARM_REL32: (S + A) | T - P
3407   static inline typename This::Status
3408   rel32(unsigned char* view,
3409         const Sized_relobj_file<32, big_endian>* object,
3410         const Symbol_value<32>* psymval,
3411         Arm_address address,
3412         Arm_address thumb_bit)
3413   {
3414     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3415     Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3416     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3417     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3418     return This::STATUS_OKAY;
3419   }
3420
3421   // R_ARM_THM_JUMP24: (S + A) | T - P
3422   static typename This::Status
3423   thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3424              const Symbol_value<32>* psymval, Arm_address address,
3425              Arm_address thumb_bit);
3426
3427   // R_ARM_THM_JUMP6: S + A - P
3428   static inline typename This::Status
3429   thm_jump6(unsigned char* view,
3430             const Sized_relobj_file<32, big_endian>* object,
3431             const Symbol_value<32>* psymval,
3432             Arm_address address)
3433   {
3434     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3435     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3436     Valtype* wv = reinterpret_cast<Valtype*>(view);
3437     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3438     // bit[9]:bit[7:3]:'0' (mask: 0x02f8)
3439     Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3440     Reltype x = (psymval->value(object, addend) - address);
3441     val = (val & 0xfd07) | ((x  & 0x0040) << 3) | ((val & 0x003e) << 2);
3442     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3443     // CZB does only forward jumps.
3444     return ((x > 0x007e)
3445             ? This::STATUS_OVERFLOW
3446             : This::STATUS_OKAY);
3447   }
3448
3449   // R_ARM_THM_JUMP8: S + A - P
3450   static inline typename This::Status
3451   thm_jump8(unsigned char* view,
3452             const Sized_relobj_file<32, big_endian>* object,
3453             const Symbol_value<32>* psymval,
3454             Arm_address address)
3455   {
3456     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3457     Valtype* wv = reinterpret_cast<Valtype*>(view);
3458     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3459     int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1);
3460     int32_t x = (psymval->value(object, addend) - address);
3461     elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00)
3462                                                 | ((x & 0x01fe) >> 1)));
3463     // We do a 9-bit overflow check because x is right-shifted by 1 bit.
3464     return (Bits<9>::has_overflow32(x)
3465             ? This::STATUS_OVERFLOW
3466             : This::STATUS_OKAY);
3467   }
3468
3469   // R_ARM_THM_JUMP11: S + A - P
3470   static inline typename This::Status
3471   thm_jump11(unsigned char* view,
3472             const Sized_relobj_file<32, big_endian>* object,
3473             const Symbol_value<32>* psymval,
3474             Arm_address address)
3475   {
3476     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3477     Valtype* wv = reinterpret_cast<Valtype*>(view);
3478     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3479     int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1);
3480     int32_t x = (psymval->value(object, addend) - address);
3481     elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800)
3482                                                 | ((x & 0x0ffe) >> 1)));
3483     // We do a 12-bit overflow check because x is right-shifted by 1 bit.
3484     return (Bits<12>::has_overflow32(x)
3485             ? This::STATUS_OVERFLOW
3486             : This::STATUS_OKAY);
3487   }
3488
3489   // R_ARM_BASE_PREL: B(S) + A - P
3490   static inline typename This::Status
3491   base_prel(unsigned char* view,
3492             Arm_address origin,
3493             Arm_address address)
3494   {
3495     Base::rel32(view, origin - address);
3496     return STATUS_OKAY;
3497   }
3498
3499   // R_ARM_BASE_ABS: B(S) + A
3500   static inline typename This::Status
3501   base_abs(unsigned char* view,
3502            Arm_address origin)
3503   {
3504     Base::rel32(view, origin);
3505     return STATUS_OKAY;
3506   }
3507
3508   // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3509   static inline typename This::Status
3510   got_brel(unsigned char* view,
3511            typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3512   {
3513     Base::rel32(view, got_offset);
3514     return This::STATUS_OKAY;
3515   }
3516
3517   // R_ARM_GOT_PREL: GOT(S) + A - P
3518   static inline typename This::Status
3519   got_prel(unsigned char* view,
3520            Arm_address got_entry,
3521            Arm_address address)
3522   {
3523     Base::rel32(view, got_entry - address);
3524     return This::STATUS_OKAY;
3525   }
3526
3527   // R_ARM_PREL: (S + A) | T - P
3528   static inline typename This::Status
3529   prel31(unsigned char* view,
3530          const Sized_relobj_file<32, big_endian>* object,
3531          const Symbol_value<32>* psymval,
3532          Arm_address address,
3533          Arm_address thumb_bit)
3534   {
3535     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3536     Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3537     Valtype addend = Bits<31>::sign_extend32(val);
3538     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3539     val = Bits<32>::bit_select32(val, x, 0x7fffffffU);
3540     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val);
3541     return (Bits<31>::has_overflow32(x)
3542             ? This::STATUS_OVERFLOW
3543             : This::STATUS_OKAY);
3544   }
3545
3546   // R_ARM_MOVW_ABS_NC: (S + A) | T     (relative address base is )
3547   // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3548   // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3549   // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3550   static inline typename This::Status
3551   movw(unsigned char* view,
3552        const Sized_relobj_file<32, big_endian>* object,
3553        const Symbol_value<32>* psymval,
3554        Arm_address relative_address_base,
3555        Arm_address thumb_bit,
3556        bool check_overflow)
3557   {
3558     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3559     Valtype* wv = reinterpret_cast<Valtype*>(view);
3560     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3561     Valtype addend = This::extract_arm_movw_movt_addend(val);
3562     Valtype x = ((psymval->value(object, addend) | thumb_bit)
3563                  - relative_address_base);
3564     val = This::insert_val_arm_movw_movt(val, x);
3565     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3566     return ((check_overflow && Bits<16>::has_overflow32(x))
3567             ? This::STATUS_OVERFLOW
3568             : This::STATUS_OKAY);
3569   }
3570
3571   // R_ARM_MOVT_ABS: S + A      (relative address base is 0)
3572   // R_ARM_MOVT_PREL: S + A - P
3573   // R_ARM_MOVT_BREL: S + A - B(S)
3574   static inline typename This::Status
3575   movt(unsigned char* view,
3576        const Sized_relobj_file<32, big_endian>* object,
3577        const Symbol_value<32>* psymval,
3578        Arm_address relative_address_base)
3579   {
3580     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3581     Valtype* wv = reinterpret_cast<Valtype*>(view);
3582     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3583     Valtype addend = This::extract_arm_movw_movt_addend(val);
3584     Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3585     val = This::insert_val_arm_movw_movt(val, x);
3586     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3587     // FIXME: IHI0044D says that we should check for overflow.
3588     return This::STATUS_OKAY;
3589   }
3590
3591   // R_ARM_THM_MOVW_ABS_NC: S + A | T           (relative_address_base is 0)
3592   // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3593   // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3594   // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3595   static inline typename This::Status
3596   thm_movw(unsigned char* view,
3597            const Sized_relobj_file<32, big_endian>* object,
3598            const Symbol_value<32>* psymval,
3599            Arm_address relative_address_base,
3600            Arm_address thumb_bit,
3601            bool check_overflow)
3602   {
3603     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3604     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3605     Valtype* wv = reinterpret_cast<Valtype*>(view);
3606     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3607                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3608     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3609     Reltype x =
3610       (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3611     val = This::insert_val_thumb_movw_movt(val, x);
3612     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3613     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3614     return ((check_overflow && Bits<16>::has_overflow32(x))
3615             ? This::STATUS_OVERFLOW
3616             : This::STATUS_OKAY);
3617   }
3618
3619   // R_ARM_THM_MOVT_ABS: S + A          (relative address base is 0)
3620   // R_ARM_THM_MOVT_PREL: S + A - P
3621   // R_ARM_THM_MOVT_BREL: S + A - B(S)
3622   static inline typename This::Status
3623   thm_movt(unsigned char* view,
3624            const Sized_relobj_file<32, big_endian>* object,
3625            const Symbol_value<32>* psymval,
3626            Arm_address relative_address_base)
3627   {
3628     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3629     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3630     Valtype* wv = reinterpret_cast<Valtype*>(view);
3631     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3632                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3633     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3634     Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3635     val = This::insert_val_thumb_movw_movt(val, x);
3636     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3637     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3638     return This::STATUS_OKAY;
3639   }
3640
3641   // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3642   static inline typename This::Status
3643   thm_alu11(unsigned char* view,
3644             const Sized_relobj_file<32, big_endian>* object,
3645             const Symbol_value<32>* psymval,
3646             Arm_address address,
3647             Arm_address thumb_bit)
3648   {
3649     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3650     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3651     Valtype* wv = reinterpret_cast<Valtype*>(view);
3652     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3653                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3654
3655     //        f e d c b|a|9|8 7 6 5|4|3 2 1 0||f|e d c|b a 9 8|7 6 5 4 3 2 1 0
3656     // -----------------------------------------------------------------------
3657     // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd     |imm8
3658     // ADDW   1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd     |imm8
3659     // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd     |imm8
3660     // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd     |imm8
3661     // SUBW   1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd     |imm8
3662     // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd     |imm8
3663
3664     // Determine a sign for the addend.
3665     const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3666                       || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3667     // Thumb2 addend encoding:
3668     // imm12 := i | imm3 | imm8
3669     int32_t addend = (insn & 0xff)
3670                      | ((insn & 0x00007000) >> 4)
3671                      | ((insn & 0x04000000) >> 15);
3672     // Apply a sign to the added.
3673     addend *= sign;
3674
3675     int32_t x = (psymval->value(object, addend) | thumb_bit)
3676                 - (address & 0xfffffffc);
3677     Reltype val = abs(x);
3678     // Mask out the value and a distinct part of the ADD/SUB opcode
3679     // (bits 7:5 of opword).
3680     insn = (insn & 0xfb0f8f00)
3681            | (val & 0xff)
3682            | ((val & 0x700) << 4)
3683            | ((val & 0x800) << 15);
3684     // Set the opcode according to whether the value to go in the
3685     // place is negative.
3686     if (x < 0)
3687       insn |= 0x00a00000;
3688
3689     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3690     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3691     return ((val > 0xfff) ?
3692             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3693   }
3694
3695   // R_ARM_THM_PC8: S + A - Pa (Thumb)
3696   static inline typename This::Status
3697   thm_pc8(unsigned char* view,
3698           const Sized_relobj_file<32, big_endian>* object,
3699           const Symbol_value<32>* psymval,
3700           Arm_address address)
3701   {
3702     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3703     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3704     Valtype* wv = reinterpret_cast<Valtype*>(view);
3705     Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3706     Reltype addend = ((insn & 0x00ff) << 2);
3707     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3708     Reltype val = abs(x);
3709     insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3710
3711     elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3712     return ((val > 0x03fc)
3713             ? This::STATUS_OVERFLOW
3714             : This::STATUS_OKAY);
3715   }
3716
3717   // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3718   static inline typename This::Status
3719   thm_pc12(unsigned char* view,
3720            const Sized_relobj_file<32, big_endian>* object,
3721            const Symbol_value<32>* psymval,
3722            Arm_address address)
3723   {
3724     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3725     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3726     Valtype* wv = reinterpret_cast<Valtype*>(view);
3727     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3728                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3729     // Determine a sign for the addend (positive if the U bit is 1).
3730     const int sign = (insn & 0x00800000) ? 1 : -1;
3731     int32_t addend = (insn & 0xfff);
3732     // Apply a sign to the added.
3733     addend *= sign;
3734
3735     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3736     Reltype val = abs(x);
3737     // Mask out and apply the value and the U bit.
3738     insn = (insn & 0xff7ff000) | (val & 0xfff);
3739     // Set the U bit according to whether the value to go in the
3740     // place is positive.
3741     if (x >= 0)
3742       insn |= 0x00800000;
3743
3744     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3745     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3746     return ((val > 0xfff) ?
3747             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3748   }
3749
3750   // R_ARM_V4BX
3751   static inline typename This::Status
3752   v4bx(const Relocate_info<32, big_endian>* relinfo,
3753        unsigned char* view,
3754        const Arm_relobj<big_endian>* object,
3755        const Arm_address address,
3756        const bool is_interworking)
3757   {
3758
3759     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3760     Valtype* wv = reinterpret_cast<Valtype*>(view);
3761     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3762
3763     // Ensure that we have a BX instruction.
3764     gold_assert((val & 0x0ffffff0) == 0x012fff10);
3765     const uint32_t reg = (val & 0xf);
3766     if (is_interworking && reg != 0xf)
3767       {
3768         Stub_table<big_endian>* stub_table =
3769             object->stub_table(relinfo->data_shndx);
3770         gold_assert(stub_table != NULL);
3771
3772         Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3773         gold_assert(stub != NULL);
3774
3775         int32_t veneer_address =
3776             stub_table->address() + stub->offset() - 8 - address;
3777         gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3778                     && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3779         // Replace with a branch to veneer (B <addr>)
3780         val = (val & 0xf0000000) | 0x0a000000
3781               | ((veneer_address >> 2) & 0x00ffffff);
3782       }
3783     else
3784       {
3785         // Preserve Rm (lowest four bits) and the condition code
3786         // (highest four bits). Other bits encode MOV PC,Rm.
3787         val = (val & 0xf000000f) | 0x01a0f000;
3788       }
3789     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3790     return This::STATUS_OKAY;
3791   }
3792
3793   // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3794   // R_ARM_ALU_PC_G0:    ((S + A) | T) - P
3795   // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3796   // R_ARM_ALU_PC_G1:    ((S + A) | T) - P
3797   // R_ARM_ALU_PC_G2:    ((S + A) | T) - P
3798   // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3799   // R_ARM_ALU_SB_G0:    ((S + A) | T) - B(S)
3800   // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3801   // R_ARM_ALU_SB_G1:    ((S + A) | T) - B(S)
3802   // R_ARM_ALU_SB_G2:    ((S + A) | T) - B(S)
3803   static inline typename This::Status
3804   arm_grp_alu(unsigned char* view,
3805         const Sized_relobj_file<32, big_endian>* object,
3806         const Symbol_value<32>* psymval,
3807         const int group,
3808         Arm_address address,
3809         Arm_address thumb_bit,
3810         bool check_overflow)
3811   {
3812     gold_assert(group >= 0 && group < 3);
3813     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3814     Valtype* wv = reinterpret_cast<Valtype*>(view);
3815     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3816
3817     // ALU group relocations are allowed only for the ADD/SUB instructions.
3818     // (0x00800000 - ADD, 0x00400000 - SUB)
3819     const Valtype opcode = insn & 0x01e00000;
3820     if (opcode != 0x00800000 && opcode != 0x00400000)
3821       return This::STATUS_BAD_RELOC;
3822
3823     // Determine a sign for the addend.
3824     const int sign = (opcode == 0x00800000) ? 1 : -1;
3825     // shifter = rotate_imm * 2
3826     const uint32_t shifter = (insn & 0xf00) >> 7;
3827     // Initial addend value.
3828     int32_t addend = insn & 0xff;
3829     // Rotate addend right by shifter.
3830     addend = (addend >> shifter) | (addend << (32 - shifter));
3831     // Apply a sign to the added.
3832     addend *= sign;
3833
3834     int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3835     Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3836     // Check for overflow if required
3837     if (check_overflow
3838         && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3839       return This::STATUS_OVERFLOW;
3840
3841     // Mask out the value and the ADD/SUB part of the opcode; take care
3842     // not to destroy the S bit.
3843     insn &= 0xff1ff000;
3844     // Set the opcode according to whether the value to go in the
3845     // place is negative.
3846     insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3847     // Encode the offset (encoded Gn).
3848     insn |= gn;
3849
3850     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3851     return This::STATUS_OKAY;
3852   }
3853
3854   // R_ARM_LDR_PC_G0: S + A - P
3855   // R_ARM_LDR_PC_G1: S + A - P
3856   // R_ARM_LDR_PC_G2: S + A - P
3857   // R_ARM_LDR_SB_G0: S + A - B(S)
3858   // R_ARM_LDR_SB_G1: S + A - B(S)
3859   // R_ARM_LDR_SB_G2: S + A - B(S)
3860   static inline typename This::Status
3861   arm_grp_ldr(unsigned char* view,
3862         const Sized_relobj_file<32, big_endian>* object,
3863         const Symbol_value<32>* psymval,
3864         const int group,
3865         Arm_address address)
3866   {
3867     gold_assert(group >= 0 && group < 3);
3868     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3869     Valtype* wv = reinterpret_cast<Valtype*>(view);
3870     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3871
3872     const int sign = (insn & 0x00800000) ? 1 : -1;
3873     int32_t addend = (insn & 0xfff) * sign;
3874     int32_t x = (psymval->value(object, addend) - address);
3875     // Calculate the relevant G(n-1) value to obtain this stage residual.
3876     Valtype residual =
3877         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3878     if (residual >= 0x1000)
3879       return This::STATUS_OVERFLOW;
3880
3881     // Mask out the value and U bit.
3882     insn &= 0xff7ff000;
3883     // Set the U bit for non-negative values.
3884     if (x >= 0)
3885       insn |= 0x00800000;
3886     insn |= residual;
3887
3888     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3889     return This::STATUS_OKAY;
3890   }
3891
3892   // R_ARM_LDRS_PC_G0: S + A - P
3893   // R_ARM_LDRS_PC_G1: S + A - P
3894   // R_ARM_LDRS_PC_G2: S + A - P
3895   // R_ARM_LDRS_SB_G0: S + A - B(S)
3896   // R_ARM_LDRS_SB_G1: S + A - B(S)
3897   // R_ARM_LDRS_SB_G2: S + A - B(S)
3898   static inline typename This::Status
3899   arm_grp_ldrs(unsigned char* view,
3900         const Sized_relobj_file<32, big_endian>* object,
3901         const Symbol_value<32>* psymval,
3902         const int group,
3903         Arm_address address)
3904   {
3905     gold_assert(group >= 0 && group < 3);
3906     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3907     Valtype* wv = reinterpret_cast<Valtype*>(view);
3908     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3909
3910     const int sign = (insn & 0x00800000) ? 1 : -1;
3911     int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3912     int32_t x = (psymval->value(object, addend) - address);
3913     // Calculate the relevant G(n-1) value to obtain this stage residual.
3914     Valtype residual =
3915         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3916    if (residual >= 0x100)
3917       return This::STATUS_OVERFLOW;
3918
3919     // Mask out the value and U bit.
3920     insn &= 0xff7ff0f0;
3921     // Set the U bit for non-negative values.
3922     if (x >= 0)
3923       insn |= 0x00800000;
3924     insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3925
3926     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3927     return This::STATUS_OKAY;
3928   }
3929
3930   // R_ARM_LDC_PC_G0: S + A - P
3931   // R_ARM_LDC_PC_G1: S + A - P
3932   // R_ARM_LDC_PC_G2: S + A - P
3933   // R_ARM_LDC_SB_G0: S + A - B(S)
3934   // R_ARM_LDC_SB_G1: S + A - B(S)
3935   // R_ARM_LDC_SB_G2: S + A - B(S)
3936   static inline typename This::Status
3937   arm_grp_ldc(unsigned char* view,
3938       const Sized_relobj_file<32, big_endian>* object,
3939       const Symbol_value<32>* psymval,
3940       const int group,
3941       Arm_address address)
3942   {
3943     gold_assert(group >= 0 && group < 3);
3944     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3945     Valtype* wv = reinterpret_cast<Valtype*>(view);
3946     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3947
3948     const int sign = (insn & 0x00800000) ? 1 : -1;
3949     int32_t addend = ((insn & 0xff) << 2) * sign;
3950     int32_t x = (psymval->value(object, addend) - address);
3951     // Calculate the relevant G(n-1) value to obtain this stage residual.
3952     Valtype residual =
3953       Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3954     if ((residual & 0x3) != 0 || residual >= 0x400)
3955       return This::STATUS_OVERFLOW;
3956
3957     // Mask out the value and U bit.
3958     insn &= 0xff7fff00;
3959     // Set the U bit for non-negative values.
3960     if (x >= 0)
3961       insn |= 0x00800000;
3962     insn |= (residual >> 2);
3963
3964     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3965     return This::STATUS_OKAY;
3966   }
3967 };
3968
3969 // Relocate ARM long branches.  This handles relocation types
3970 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3971 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3972 // undefined and we do not use PLT in this relocation.  In such a case,
3973 // the branch is converted into an NOP.
3974
3975 template<bool big_endian>
3976 typename Arm_relocate_functions<big_endian>::Status
3977 Arm_relocate_functions<big_endian>::arm_branch_common(
3978     unsigned int r_type,
3979     const Relocate_info<32, big_endian>* relinfo,
3980     unsigned char* view,
3981     const Sized_symbol<32>* gsym,
3982     const Arm_relobj<big_endian>* object,
3983     unsigned int r_sym,
3984     const Symbol_value<32>* psymval,
3985     Arm_address address,
3986     Arm_address thumb_bit,
3987     bool is_weakly_undefined_without_plt)
3988 {
3989   typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3990   Valtype* wv = reinterpret_cast<Valtype*>(view);
3991   Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3992
3993   bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3994                     && ((val & 0x0f000000UL) == 0x0a000000UL);
3995   bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3996   bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3997                           && ((val & 0x0f000000UL) == 0x0b000000UL);
3998   bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3999   bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
4000
4001   // Check that the instruction is valid.
4002   if (r_type == elfcpp::R_ARM_CALL)
4003     {
4004       if (!insn_is_uncond_bl && !insn_is_blx)
4005         return This::STATUS_BAD_RELOC;
4006     }
4007   else if (r_type == elfcpp::R_ARM_JUMP24)
4008     {
4009       if (!insn_is_b && !insn_is_cond_bl)
4010         return This::STATUS_BAD_RELOC;
4011     }
4012   else if (r_type == elfcpp::R_ARM_PLT32)
4013     {
4014       if (!insn_is_any_branch)
4015         return This::STATUS_BAD_RELOC;
4016     }
4017   else if (r_type == elfcpp::R_ARM_XPC25)
4018     {
4019       // FIXME: AAELF document IH0044C does not say much about it other
4020       // than it being obsolete.
4021       if (!insn_is_any_branch)
4022         return This::STATUS_BAD_RELOC;
4023     }
4024   else
4025     gold_unreachable();
4026
4027   // A branch to an undefined weak symbol is turned into a jump to
4028   // the next instruction unless a PLT entry will be created.
4029   // Do the same for local undefined symbols.
4030   // The jump to the next instruction is optimized as a NOP depending
4031   // on the architecture.
4032   const Target_arm<big_endian>* arm_target =
4033     Target_arm<big_endian>::default_target();
4034   if (is_weakly_undefined_without_plt)
4035     {
4036       gold_assert(!parameters->options().relocatable());
4037       Valtype cond = val & 0xf0000000U;
4038       if (arm_target->may_use_arm_nop())
4039         val = cond | 0x0320f000;
4040       else
4041         val = cond | 0x01a00000;        // Using pre-UAL nop: mov r0, r0.
4042       elfcpp::Swap<32, big_endian>::writeval(wv, val);
4043       return This::STATUS_OKAY;
4044     }
4045
4046   Valtype addend = Bits<26>::sign_extend32(val << 2);
4047   Valtype branch_target = psymval->value(object, addend);
4048   int32_t branch_offset = branch_target - address;
4049
4050   // We need a stub if the branch offset is too large or if we need
4051   // to switch mode.
4052   bool may_use_blx = arm_target->may_use_v5t_interworking();
4053   Reloc_stub* stub = NULL;
4054
4055   if (!parameters->options().relocatable()
4056       && (Bits<26>::has_overflow32(branch_offset)
4057           || ((thumb_bit != 0)
4058               && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
4059     {
4060       Valtype unadjusted_branch_target = psymval->value(object, 0);
4061
4062       Stub_type stub_type =
4063         Reloc_stub::stub_type_for_reloc(r_type, address,
4064                                         unadjusted_branch_target,
4065                                         (thumb_bit != 0));
4066       if (stub_type != arm_stub_none)
4067         {
4068           Stub_table<big_endian>* stub_table =
4069             object->stub_table(relinfo->data_shndx);
4070           gold_assert(stub_table != NULL);
4071
4072           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4073           stub = stub_table->find_reloc_stub(stub_key);
4074           gold_assert(stub != NULL);
4075           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4076           branch_target = stub_table->address() + stub->offset() + addend;
4077           branch_offset = branch_target - address;
4078           gold_assert(!Bits<26>::has_overflow32(branch_offset));
4079         }
4080     }
4081
4082   // At this point, if we still need to switch mode, the instruction
4083   // must either be a BLX or a BL that can be converted to a BLX.
4084   if (thumb_bit != 0)
4085     {
4086       // Turn BL to BLX.
4087       gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
4088       val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
4089     }
4090
4091   val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL);
4092   elfcpp::Swap<32, big_endian>::writeval(wv, val);
4093   return (Bits<26>::has_overflow32(branch_offset)
4094           ? This::STATUS_OVERFLOW
4095           : This::STATUS_OKAY);
4096 }
4097
4098 // Relocate THUMB long branches.  This handles relocation types
4099 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
4100 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
4101 // undefined and we do not use PLT in this relocation.  In such a case,
4102 // the branch is converted into an NOP.
4103
4104 template<bool big_endian>
4105 typename Arm_relocate_functions<big_endian>::Status
4106 Arm_relocate_functions<big_endian>::thumb_branch_common(
4107     unsigned int r_type,
4108     const Relocate_info<32, big_endian>* relinfo,
4109     unsigned char* view,
4110     const Sized_symbol<32>* gsym,
4111     const Arm_relobj<big_endian>* object,
4112     unsigned int r_sym,
4113     const Symbol_value<32>* psymval,
4114     Arm_address address,
4115     Arm_address thumb_bit,
4116     bool is_weakly_undefined_without_plt)
4117 {
4118   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4119   Valtype* wv = reinterpret_cast<Valtype*>(view);
4120   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4121   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4122
4123   // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
4124   // into account.
4125   bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
4126   bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
4127
4128   // Check that the instruction is valid.
4129   if (r_type == elfcpp::R_ARM_THM_CALL)
4130     {
4131       if (!is_bl_insn && !is_blx_insn)
4132         return This::STATUS_BAD_RELOC;
4133     }
4134   else if (r_type == elfcpp::R_ARM_THM_JUMP24)
4135     {
4136       // This cannot be a BLX.
4137       if (!is_bl_insn)
4138         return This::STATUS_BAD_RELOC;
4139     }
4140   else if (r_type == elfcpp::R_ARM_THM_XPC22)
4141     {
4142       // Check for Thumb to Thumb call.
4143       if (!is_blx_insn)
4144         return This::STATUS_BAD_RELOC;
4145       if (thumb_bit != 0)
4146         {
4147           gold_warning(_("%s: Thumb BLX instruction targets "
4148                          "thumb function '%s'."),
4149                          object->name().c_str(),
4150                          (gsym ? gsym->name() : "(local)"));
4151           // Convert BLX to BL.
4152           lower_insn |= 0x1000U;
4153         }
4154     }
4155   else
4156     gold_unreachable();
4157
4158   // A branch to an undefined weak symbol is turned into a jump to
4159   // the next instruction unless a PLT entry will be created.
4160   // The jump to the next instruction is optimized as a NOP.W for
4161   // Thumb-2 enabled architectures.
4162   const Target_arm<big_endian>* arm_target =
4163     Target_arm<big_endian>::default_target();
4164   if (is_weakly_undefined_without_plt)
4165     {
4166       gold_assert(!parameters->options().relocatable());
4167       if (arm_target->may_use_thumb2_nop())
4168         {
4169           elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4170           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4171         }
4172       else
4173         {
4174           elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4175           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4176         }
4177       return This::STATUS_OKAY;
4178     }
4179
4180   int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4181   Arm_address branch_target = psymval->value(object, addend);
4182
4183   // For BLX, bit 1 of target address comes from bit 1 of base address.
4184   bool may_use_blx = arm_target->may_use_v5t_interworking();
4185   if (thumb_bit == 0 && may_use_blx)
4186     branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4187
4188   int32_t branch_offset = branch_target - address;
4189
4190   // We need a stub if the branch offset is too large or if we need
4191   // to switch mode.
4192   bool thumb2 = arm_target->using_thumb2();
4193   if (!parameters->options().relocatable()
4194       && ((!thumb2 && Bits<23>::has_overflow32(branch_offset))
4195           || (thumb2 && Bits<25>::has_overflow32(branch_offset))
4196           || ((thumb_bit == 0)
4197               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4198                   || r_type == elfcpp::R_ARM_THM_JUMP24))))
4199     {
4200       Arm_address unadjusted_branch_target = psymval->value(object, 0);
4201
4202       Stub_type stub_type =
4203         Reloc_stub::stub_type_for_reloc(r_type, address,
4204                                         unadjusted_branch_target,
4205                                         (thumb_bit != 0));
4206
4207       if (stub_type != arm_stub_none)
4208         {
4209           Stub_table<big_endian>* stub_table =
4210             object->stub_table(relinfo->data_shndx);
4211           gold_assert(stub_table != NULL);
4212
4213           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4214           Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4215           gold_assert(stub != NULL);
4216           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4217           branch_target = stub_table->address() + stub->offset() + addend;
4218           if (thumb_bit == 0 && may_use_blx)
4219             branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4220           branch_offset = branch_target - address;
4221         }
4222     }
4223
4224   // At this point, if we still need to switch mode, the instruction
4225   // must either be a BLX or a BL that can be converted to a BLX.
4226   if (thumb_bit == 0)
4227     {
4228       gold_assert(may_use_blx
4229                   && (r_type == elfcpp::R_ARM_THM_CALL
4230                       || r_type == elfcpp::R_ARM_THM_XPC22));
4231       // Make sure this is a BLX.
4232       lower_insn &= ~0x1000U;
4233     }
4234   else
4235     {
4236       // Make sure this is a BL.
4237       lower_insn |= 0x1000U;
4238     }
4239
4240   // For a BLX instruction, make sure that the relocation is rounded up
4241   // to a word boundary.  This follows the semantics of the instruction
4242   // which specifies that bit 1 of the target address will come from bit
4243   // 1 of the base address.
4244   if ((lower_insn & 0x5000U) == 0x4000U)
4245     gold_assert((branch_offset & 3) == 0);
4246
4247   // Put BRANCH_OFFSET back into the insn.  Assumes two's complement.
4248   // We use the Thumb-2 encoding, which is safe even if dealing with
4249   // a Thumb-1 instruction by virtue of our overflow check above.  */
4250   upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4251   lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4252
4253   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4254   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4255
4256   gold_assert(!Bits<25>::has_overflow32(branch_offset));
4257
4258   return ((thumb2
4259            ? Bits<25>::has_overflow32(branch_offset)
4260            : Bits<23>::has_overflow32(branch_offset))
4261           ? This::STATUS_OVERFLOW
4262           : This::STATUS_OKAY);
4263 }
4264
4265 // Relocate THUMB-2 long conditional branches.
4266 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
4267 // undefined and we do not use PLT in this relocation.  In such a case,
4268 // the branch is converted into an NOP.
4269
4270 template<bool big_endian>
4271 typename Arm_relocate_functions<big_endian>::Status
4272 Arm_relocate_functions<big_endian>::thm_jump19(
4273     unsigned char* view,
4274     const Arm_relobj<big_endian>* object,
4275     const Symbol_value<32>* psymval,
4276     Arm_address address,
4277     Arm_address thumb_bit)
4278 {
4279   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4280   Valtype* wv = reinterpret_cast<Valtype*>(view);
4281   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4282   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4283   int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4284
4285   Arm_address branch_target = psymval->value(object, addend);
4286   int32_t branch_offset = branch_target - address;
4287
4288   // ??? Should handle interworking?  GCC might someday try to
4289   // use this for tail calls.
4290   // FIXME: We do support thumb entry to PLT yet.
4291   if (thumb_bit == 0)
4292     {
4293       gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4294       return This::STATUS_BAD_RELOC;
4295     }
4296
4297   // Put RELOCATION back into the insn.
4298   upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4299   lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4300
4301   // Put the relocated value back in the object file:
4302   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4303   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4304
4305   return (Bits<21>::has_overflow32(branch_offset)
4306           ? This::STATUS_OVERFLOW
4307           : This::STATUS_OKAY);
4308 }
4309
4310 // Get the GOT section, creating it if necessary.
4311
4312 template<bool big_endian>
4313 Arm_output_data_got<big_endian>*
4314 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4315 {
4316   if (this->got_ == NULL)
4317     {
4318       gold_assert(symtab != NULL && layout != NULL);
4319
4320       // When using -z now, we can treat .got as a relro section.
4321       // Without -z now, it is modified after program startup by lazy
4322       // PLT relocations.
4323       bool is_got_relro = parameters->options().now();
4324       Output_section_order got_order = (is_got_relro
4325                                         ? ORDER_RELRO_LAST
4326                                         : ORDER_DATA);
4327
4328       // Unlike some targets (.e.g x86), ARM does not use separate .got and
4329       // .got.plt sections in output.  The output .got section contains both
4330       // PLT and non-PLT GOT entries.
4331       this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4332
4333       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4334                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4335                                       this->got_, got_order, is_got_relro);
4336
4337       // The old GNU linker creates a .got.plt section.  We just
4338       // create another set of data in the .got section.  Note that we
4339       // always create a PLT if we create a GOT, although the PLT
4340       // might be empty.
4341       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4342       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4343                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4344                                       this->got_plt_, got_order, is_got_relro);
4345
4346       // The first three entries are reserved.
4347       this->got_plt_->set_current_data_size(3 * 4);
4348
4349       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4350       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4351                                     Symbol_table::PREDEFINED,
4352                                     this->got_plt_,
4353                                     0, 0, elfcpp::STT_OBJECT,
4354                                     elfcpp::STB_LOCAL,
4355                                     elfcpp::STV_HIDDEN, 0,
4356                                     false, false);
4357
4358       // If there are any IRELATIVE relocations, they get GOT entries
4359       // in .got.plt after the jump slot entries.
4360       this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT");
4361       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4362                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4363                                       this->got_irelative_,
4364                                       got_order, is_got_relro);
4365
4366     }
4367   return this->got_;
4368 }
4369
4370 // Get the dynamic reloc section, creating it if necessary.
4371
4372 template<bool big_endian>
4373 typename Target_arm<big_endian>::Reloc_section*
4374 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4375 {
4376   if (this->rel_dyn_ == NULL)
4377     {
4378       gold_assert(layout != NULL);
4379       // Create both relocation sections in the same place, so as to ensure
4380       // their relative order in the output section.
4381       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4382       this->rel_irelative_ = new Reloc_section(false);
4383       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4384                                       elfcpp::SHF_ALLOC, this->rel_dyn_,
4385                                       ORDER_DYNAMIC_RELOCS, false);
4386       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4387                                       elfcpp::SHF_ALLOC, this->rel_irelative_,
4388                                       ORDER_DYNAMIC_RELOCS, false);
4389     }
4390   return this->rel_dyn_;
4391 }
4392
4393
4394 // Get the section to use for IRELATIVE relocs, creating it if necessary.  These
4395 // go in .rela.dyn, but only after all other dynamic relocations.  They need to
4396 // follow the other dynamic relocations so that they can refer to global
4397 // variables initialized by those relocs.
4398
4399 template<bool big_endian>
4400 typename Target_arm<big_endian>::Reloc_section*
4401 Target_arm<big_endian>::rel_irelative_section(Layout* layout)
4402 {
4403   if (this->rel_irelative_ == NULL)
4404     {
4405       // Delegate the creation to rel_dyn_section so as to ensure their order in
4406       // the output section.
4407       this->rel_dyn_section(layout);
4408       gold_assert(this->rel_irelative_ != NULL
4409                   && (this->rel_dyn_->output_section()
4410                       == this->rel_irelative_->output_section()));
4411     }
4412   return this->rel_irelative_;
4413 }
4414
4415
4416 // Insn_template methods.
4417
4418 // Return byte size of an instruction template.
4419
4420 size_t
4421 Insn_template::size() const
4422 {
4423   switch (this->type())
4424     {
4425     case THUMB16_TYPE:
4426     case THUMB16_SPECIAL_TYPE:
4427       return 2;
4428     case ARM_TYPE:
4429     case THUMB32_TYPE:
4430     case DATA_TYPE:
4431       return 4;
4432     default:
4433       gold_unreachable();
4434     }
4435 }
4436
4437 // Return alignment of an instruction template.
4438
4439 unsigned
4440 Insn_template::alignment() const
4441 {
4442   switch (this->type())
4443     {
4444     case THUMB16_TYPE:
4445     case THUMB16_SPECIAL_TYPE:
4446     case THUMB32_TYPE:
4447       return 2;
4448     case ARM_TYPE:
4449     case DATA_TYPE:
4450       return 4;
4451     default:
4452       gold_unreachable();
4453     }
4454 }
4455
4456 // Stub_template methods.
4457
4458 Stub_template::Stub_template(
4459     Stub_type type, const Insn_template* insns,
4460      size_t insn_count)
4461   : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4462     entry_in_thumb_mode_(false), relocs_()
4463 {
4464   off_t offset = 0;
4465
4466   // Compute byte size and alignment of stub template.
4467   for (size_t i = 0; i < insn_count; i++)
4468     {
4469       unsigned insn_alignment = insns[i].alignment();
4470       size_t insn_size = insns[i].size();
4471       gold_assert((offset & (insn_alignment - 1)) == 0);
4472       this->alignment_ = std::max(this->alignment_, insn_alignment);
4473       switch (insns[i].type())
4474         {
4475         case Insn_template::THUMB16_TYPE:
4476         case Insn_template::THUMB16_SPECIAL_TYPE:
4477           if (i == 0)
4478             this->entry_in_thumb_mode_ = true;
4479           break;
4480
4481         case Insn_template::THUMB32_TYPE:
4482           if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4483             this->relocs_.push_back(Reloc(i, offset));
4484           if (i == 0)
4485             this->entry_in_thumb_mode_ = true;
4486           break;
4487
4488         case Insn_template::ARM_TYPE:
4489           // Handle cases where the target is encoded within the
4490           // instruction.
4491           if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4492             this->relocs_.push_back(Reloc(i, offset));
4493           break;
4494
4495         case Insn_template::DATA_TYPE:
4496           // Entry point cannot be data.
4497           gold_assert(i != 0);
4498           this->relocs_.push_back(Reloc(i, offset));
4499           break;
4500
4501         default:
4502           gold_unreachable();
4503         }
4504       offset += insn_size;
4505     }
4506   this->size_ = offset;
4507 }
4508
4509 // Stub methods.
4510
4511 // Template to implement do_write for a specific target endianness.
4512
4513 template<bool big_endian>
4514 void inline
4515 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4516 {
4517   const Stub_template* stub_template = this->stub_template();
4518   const Insn_template* insns = stub_template->insns();
4519   const bool enable_be8 = parameters->options().be8();
4520
4521   unsigned char* pov = view;
4522   for (size_t i = 0; i < stub_template->insn_count(); i++)
4523     {
4524       switch (insns[i].type())
4525         {
4526         case Insn_template::THUMB16_TYPE:
4527           if (enable_be8)
4528             elfcpp::Swap<16, false>::writeval(pov, insns[i].data() & 0xffff);
4529           else
4530             elfcpp::Swap<16, big_endian>::writeval(pov,
4531                                                    insns[i].data() & 0xffff);
4532           break;
4533         case Insn_template::THUMB16_SPECIAL_TYPE:
4534           if (enable_be8)
4535             elfcpp::Swap<16, false>::writeval(pov, this->thumb16_special(i));
4536           else
4537             elfcpp::Swap<16, big_endian>::writeval(pov,
4538                                                    this->thumb16_special(i));
4539           break;
4540         case Insn_template::THUMB32_TYPE:
4541           {
4542             uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4543             uint32_t lo = insns[i].data() & 0xffff;
4544             if (enable_be8)
4545               {
4546                 elfcpp::Swap<16, false>::writeval(pov, hi);
4547                 elfcpp::Swap<16, false>::writeval(pov + 2, lo);
4548               }
4549             else
4550               {
4551                 elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4552                 elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4553               }
4554           }
4555           break;
4556         case Insn_template::ARM_TYPE:
4557           if (enable_be8)
4558             elfcpp::Swap<32, false>::writeval(pov, insns[i].data());
4559           else
4560             elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4561           break;
4562         case Insn_template::DATA_TYPE:
4563           elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4564           break;
4565         default:
4566           gold_unreachable();
4567         }
4568       pov += insns[i].size();
4569     }
4570   gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4571 }
4572
4573 // Reloc_stub::Key methods.
4574
4575 // Dump a Key as a string for debugging.
4576
4577 std::string
4578 Reloc_stub::Key::name() const
4579 {
4580   if (this->r_sym_ == invalid_index)
4581     {
4582       // Global symbol key name
4583       // <stub-type>:<symbol name>:<addend>.
4584       const std::string sym_name = this->u_.symbol->name();
4585       // We need to print two hex number and two colons.  So just add 100 bytes
4586       // to the symbol name size.
4587       size_t len = sym_name.size() + 100;
4588       char* buffer = new char[len];
4589       int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4590                        sym_name.c_str(), this->addend_);
4591       gold_assert(c > 0 && c < static_cast<int>(len));
4592       delete[] buffer;
4593       return std::string(buffer);
4594     }
4595   else
4596     {
4597       // local symbol key name
4598       // <stub-type>:<object>:<r_sym>:<addend>.
4599       const size_t len = 200;
4600       char buffer[len];
4601       int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4602                        this->u_.relobj, this->r_sym_, this->addend_);
4603       gold_assert(c > 0 && c < static_cast<int>(len));
4604       return std::string(buffer);
4605     }
4606 }
4607
4608 // Reloc_stub methods.
4609
4610 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4611 // LOCATION to DESTINATION.
4612 // This code is based on the arm_type_of_stub function in
4613 // bfd/elf32-arm.c.  We have changed the interface a little to keep the Stub
4614 // class simple.
4615
4616 Stub_type
4617 Reloc_stub::stub_type_for_reloc(
4618    unsigned int r_type,
4619    Arm_address location,
4620    Arm_address destination,
4621    bool target_is_thumb)
4622 {
4623   Stub_type stub_type = arm_stub_none;
4624
4625   // This is a bit ugly but we want to avoid using a templated class for
4626   // big and little endianities.
4627   bool may_use_blx;
4628   bool should_force_pic_veneer = parameters->options().pic_veneer();
4629   bool thumb2;
4630   bool thumb_only;
4631   if (parameters->target().is_big_endian())
4632     {
4633       const Target_arm<true>* big_endian_target =
4634         Target_arm<true>::default_target();
4635       may_use_blx = big_endian_target->may_use_v5t_interworking();
4636       should_force_pic_veneer |= big_endian_target->should_force_pic_veneer();
4637       thumb2 = big_endian_target->using_thumb2();
4638       thumb_only = big_endian_target->using_thumb_only();
4639     }
4640   else
4641     {
4642       const Target_arm<false>* little_endian_target =
4643         Target_arm<false>::default_target();
4644       may_use_blx = little_endian_target->may_use_v5t_interworking();
4645       should_force_pic_veneer |=
4646         little_endian_target->should_force_pic_veneer();
4647       thumb2 = little_endian_target->using_thumb2();
4648       thumb_only = little_endian_target->using_thumb_only();
4649     }
4650
4651   int64_t branch_offset;
4652   bool output_is_position_independent =
4653       parameters->options().output_is_position_independent();
4654   if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4655     {
4656       // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4657       // base address (instruction address + 4).
4658       if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4659         destination = Bits<32>::bit_select32(destination, location, 0x2);
4660       branch_offset = static_cast<int64_t>(destination) - location;
4661
4662       // Handle cases where:
4663       // - this call goes too far (different Thumb/Thumb2 max
4664       //   distance)
4665       // - it's a Thumb->Arm call and blx is not available, or it's a
4666       //   Thumb->Arm branch (not bl). A stub is needed in this case.
4667       if ((!thumb2
4668             && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4669                 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4670           || (thumb2
4671               && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4672                   || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4673           || ((!target_is_thumb)
4674               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4675                   || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4676         {
4677           if (target_is_thumb)
4678             {
4679               // Thumb to thumb.
4680               if (!thumb_only)
4681                 {
4682                   stub_type = (output_is_position_independent
4683                                || should_force_pic_veneer)
4684                     // PIC stubs.
4685                     ? ((may_use_blx
4686                         && (r_type == elfcpp::R_ARM_THM_CALL))
4687                        // V5T and above. Stub starts with ARM code, so
4688                        // we must be able to switch mode before
4689                        // reaching it, which is only possible for 'bl'
4690                        // (ie R_ARM_THM_CALL relocation).
4691                        ? arm_stub_long_branch_any_thumb_pic
4692                        // On V4T, use Thumb code only.
4693                        : arm_stub_long_branch_v4t_thumb_thumb_pic)
4694
4695                     // non-PIC stubs.
4696                     : ((may_use_blx
4697                         && (r_type == elfcpp::R_ARM_THM_CALL))
4698                        ? arm_stub_long_branch_any_any // V5T and above.
4699                        : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4700                 }
4701               else
4702                 {
4703                   stub_type = (output_is_position_independent
4704                                || should_force_pic_veneer)
4705                     ? arm_stub_long_branch_thumb_only_pic       // PIC stub.
4706                     : arm_stub_long_branch_thumb_only;  // non-PIC stub.
4707                 }
4708             }
4709           else
4710             {
4711               // Thumb to arm.
4712
4713               // FIXME: We should check that the input section is from an
4714               // object that has interwork enabled.
4715
4716               stub_type = (output_is_position_independent
4717                            || should_force_pic_veneer)
4718                 // PIC stubs.
4719                 ? ((may_use_blx
4720                     && (r_type == elfcpp::R_ARM_THM_CALL))
4721                    ? arm_stub_long_branch_any_arm_pic   // V5T and above.
4722                    : arm_stub_long_branch_v4t_thumb_arm_pic)    // V4T.
4723
4724                 // non-PIC stubs.
4725                 : ((may_use_blx
4726                     && (r_type == elfcpp::R_ARM_THM_CALL))
4727                    ? arm_stub_long_branch_any_any       // V5T and above.
4728                    : arm_stub_long_branch_v4t_thumb_arm);       // V4T.
4729
4730               // Handle v4t short branches.
4731               if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4732                   && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4733                   && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4734                 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4735             }
4736         }
4737     }
4738   else if (r_type == elfcpp::R_ARM_CALL
4739            || r_type == elfcpp::R_ARM_JUMP24
4740            || r_type == elfcpp::R_ARM_PLT32)
4741     {
4742       branch_offset = static_cast<int64_t>(destination) - location;
4743       if (target_is_thumb)
4744         {
4745           // Arm to thumb.
4746
4747           // FIXME: We should check that the input section is from an
4748           // object that has interwork enabled.
4749
4750           // We have an extra 2-bytes reach because of
4751           // the mode change (bit 24 (H) of BLX encoding).
4752           if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4753               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4754               || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4755               || (r_type == elfcpp::R_ARM_JUMP24)
4756               || (r_type == elfcpp::R_ARM_PLT32))
4757             {
4758               stub_type = (output_is_position_independent
4759                            || should_force_pic_veneer)
4760                 // PIC stubs.
4761                 ? (may_use_blx
4762                    ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4763                    : arm_stub_long_branch_v4t_arm_thumb_pic)    // V4T stub.
4764
4765                 // non-PIC stubs.
4766                 : (may_use_blx
4767                    ? arm_stub_long_branch_any_any       // V5T and above.
4768                    : arm_stub_long_branch_v4t_arm_thumb);       // V4T.
4769             }
4770         }
4771       else
4772         {
4773           // Arm to arm.
4774           if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4775               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4776             {
4777               stub_type = (output_is_position_independent
4778                            || should_force_pic_veneer)
4779                 ? arm_stub_long_branch_any_arm_pic      // PIC stubs.
4780                 : arm_stub_long_branch_any_any;         /// non-PIC.
4781             }
4782         }
4783     }
4784
4785   return stub_type;
4786 }
4787
4788 // Cortex_a8_stub methods.
4789
4790 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4791 // I is the position of the instruction template in the stub template.
4792
4793 uint16_t
4794 Cortex_a8_stub::do_thumb16_special(size_t i)
4795 {
4796   // The only use of this is to copy condition code from a conditional
4797   // branch being worked around to the corresponding conditional branch in
4798   // to the stub.
4799   gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4800               && i == 0);
4801   uint16_t data = this->stub_template()->insns()[i].data();
4802   gold_assert((data & 0xff00U) == 0xd000U);
4803   data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4804   return data;
4805 }
4806
4807 // Stub_factory methods.
4808
4809 Stub_factory::Stub_factory()
4810 {
4811   // The instruction template sequences are declared as static
4812   // objects and initialized first time the constructor runs.
4813
4814   // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4815   // to reach the stub if necessary.
4816   static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4817     {
4818       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4819       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4820                                                 // dcd   R_ARM_ABS32(X)
4821     };
4822
4823   // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4824   // available.
4825   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4826     {
4827       Insn_template::arm_insn(0xe59fc000),      // ldr   ip, [pc, #0]
4828       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4829       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4830                                                 // dcd   R_ARM_ABS32(X)
4831     };
4832
4833   // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4834   static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4835     {
4836       Insn_template::thumb16_insn(0xb401),      // push {r0}
4837       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4838       Insn_template::thumb16_insn(0x4684),      // mov  ip, r0
4839       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4840       Insn_template::thumb16_insn(0x4760),      // bx   ip
4841       Insn_template::thumb16_insn(0xbf00),      // nop
4842       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4843                                                 // dcd  R_ARM_ABS32(X)
4844     };
4845
4846   // V4T Thumb -> Thumb long branch stub. Using the stack is not
4847   // allowed.
4848   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4849     {
4850       Insn_template::thumb16_insn(0x4778),      // bx   pc
4851       Insn_template::thumb16_insn(0x46c0),      // nop
4852       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4853       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4854       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4855                                                 // dcd  R_ARM_ABS32(X)
4856     };
4857
4858   // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4859   // available.
4860   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4861     {
4862       Insn_template::thumb16_insn(0x4778),      // bx   pc
4863       Insn_template::thumb16_insn(0x46c0),      // nop
4864       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4865       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4866                                                 // dcd   R_ARM_ABS32(X)
4867     };
4868
4869   // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4870   // one, when the destination is close enough.
4871   static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4872     {
4873       Insn_template::thumb16_insn(0x4778),              // bx   pc
4874       Insn_template::thumb16_insn(0x46c0),              // nop
4875       Insn_template::arm_rel_insn(0xea000000, -8),      // b    (X-8)
4876     };
4877
4878   // ARM/Thumb -> ARM long branch stub, PIC.  On V5T and above, use
4879   // blx to reach the stub if necessary.
4880   static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4881     {
4882       Insn_template::arm_insn(0xe59fc000),      // ldr   r12, [pc]
4883       Insn_template::arm_insn(0xe08ff00c),      // add   pc, pc, ip
4884       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4885                                                 // dcd   R_ARM_REL32(X-4)
4886     };
4887
4888   // ARM/Thumb -> Thumb long branch stub, PIC.  On V5T and above, use
4889   // blx to reach the stub if necessary.  We can not add into pc;
4890   // it is not guaranteed to mode switch (different in ARMv6 and
4891   // ARMv7).
4892   static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4893     {
4894       Insn_template::arm_insn(0xe59fc004),      // ldr   r12, [pc, #4]
4895       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4896       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4897       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4898                                                 // dcd   R_ARM_REL32(X)
4899     };
4900
4901   // V4T ARM -> ARM long branch stub, PIC.
4902   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4903     {
4904       Insn_template::arm_insn(0xe59fc004),      // ldr   ip, [pc, #4]
4905       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4906       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4907       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4908                                                 // dcd   R_ARM_REL32(X)
4909     };
4910
4911   // V4T Thumb -> ARM long branch stub, PIC.
4912   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4913     {
4914       Insn_template::thumb16_insn(0x4778),      // bx   pc
4915       Insn_template::thumb16_insn(0x46c0),      // nop
4916       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4917       Insn_template::arm_insn(0xe08cf00f),      // add  pc, ip, pc
4918       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4919                                                 // dcd  R_ARM_REL32(X)
4920     };
4921
4922   // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4923   // architectures.
4924   static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4925     {
4926       Insn_template::thumb16_insn(0xb401),      // push {r0}
4927       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4928       Insn_template::thumb16_insn(0x46fc),      // mov  ip, pc
4929       Insn_template::thumb16_insn(0x4484),      // add  ip, r0
4930       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4931       Insn_template::thumb16_insn(0x4760),      // bx   ip
4932       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4933                                                 // dcd  R_ARM_REL32(X)
4934     };
4935
4936   // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4937   // allowed.
4938   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4939     {
4940       Insn_template::thumb16_insn(0x4778),      // bx   pc
4941       Insn_template::thumb16_insn(0x46c0),      // nop
4942       Insn_template::arm_insn(0xe59fc004),      // ldr  ip, [pc, #4]
4943       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4944       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4945       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4946                                                 // dcd  R_ARM_REL32(X)
4947     };
4948
4949   // Cortex-A8 erratum-workaround stubs.
4950
4951   // Stub used for conditional branches (which may be beyond +/-1MB away,
4952   // so we can't use a conditional branch to reach this stub).
4953
4954   // original code:
4955   //
4956   //    b<cond> X
4957   // after:
4958   //
4959   static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4960     {
4961       Insn_template::thumb16_bcond_insn(0xd001),        //      b<cond>.n true
4962       Insn_template::thumb32_b_insn(0xf000b800, -4),    //      b.w after
4963       Insn_template::thumb32_b_insn(0xf000b800, -4)     // true:
4964                                                         //      b.w X
4965     };
4966
4967   // Stub used for b.w and bl.w instructions.
4968
4969   static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4970     {
4971       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4972     };
4973
4974   static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4975     {
4976       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4977     };
4978
4979   // Stub used for Thumb-2 blx.w instructions.  We modified the original blx.w
4980   // instruction (which switches to ARM mode) to point to this stub.  Jump to
4981   // the real destination using an ARM-mode branch.
4982   static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4983     {
4984       Insn_template::arm_rel_insn(0xea000000, -8)       // b dest
4985     };
4986
4987   // Stub used to provide an interworking for R_ARM_V4BX relocation
4988   // (bx r[n] instruction).
4989   static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4990     {
4991       Insn_template::arm_insn(0xe3100001),              // tst   r<n>, #1
4992       Insn_template::arm_insn(0x01a0f000),              // moveq pc, r<n>
4993       Insn_template::arm_insn(0xe12fff10)               // bx    r<n>
4994     };
4995
4996   // Fill in the stub template look-up table.  Stub templates are constructed
4997   // per instance of Stub_factory for fast look-up without locking
4998   // in a thread-enabled environment.
4999
5000   this->stub_templates_[arm_stub_none] =
5001     new Stub_template(arm_stub_none, NULL, 0);
5002
5003 #define DEF_STUB(x)     \
5004   do \
5005     { \
5006       size_t array_size \
5007         = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
5008       Stub_type type = arm_stub_##x; \
5009       this->stub_templates_[type] = \
5010         new Stub_template(type, elf32_arm_stub_##x, array_size); \
5011     } \
5012   while (0);
5013
5014   DEF_STUBS
5015 #undef DEF_STUB
5016 }
5017
5018 // Stub_table methods.
5019
5020 // Remove all Cortex-A8 stub.
5021
5022 template<bool big_endian>
5023 void
5024 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
5025 {
5026   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
5027        p != this->cortex_a8_stubs_.end();
5028        ++p)
5029     delete p->second;
5030   this->cortex_a8_stubs_.clear();
5031 }
5032
5033 // Relocate one stub.  This is a helper for Stub_table::relocate_stubs().
5034
5035 template<bool big_endian>
5036 void
5037 Stub_table<big_endian>::relocate_stub(
5038     Stub* stub,
5039     const Relocate_info<32, big_endian>* relinfo,
5040     Target_arm<big_endian>* arm_target,
5041     Output_section* output_section,
5042     unsigned char* view,
5043     Arm_address address,
5044     section_size_type view_size)
5045 {
5046   const Stub_template* stub_template = stub->stub_template();
5047   if (stub_template->reloc_count() != 0)
5048     {
5049       // Adjust view to cover the stub only.
5050       section_size_type offset = stub->offset();
5051       section_size_type stub_size = stub_template->size();
5052       gold_assert(offset + stub_size <= view_size);
5053
5054       arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
5055                                 address + offset, stub_size);
5056     }
5057 }
5058
5059 // Relocate all stubs in this stub table.
5060
5061 template<bool big_endian>
5062 void
5063 Stub_table<big_endian>::relocate_stubs(
5064     const Relocate_info<32, big_endian>* relinfo,
5065     Target_arm<big_endian>* arm_target,
5066     Output_section* output_section,
5067     unsigned char* view,
5068     Arm_address address,
5069     section_size_type view_size)
5070 {
5071   // If we are passed a view bigger than the stub table's.  we need to
5072   // adjust the view.
5073   gold_assert(address == this->address()
5074               && (view_size
5075                   == static_cast<section_size_type>(this->data_size())));
5076
5077   // Relocate all relocation stubs.
5078   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
5079       p != this->reloc_stubs_.end();
5080       ++p)
5081     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
5082                         address, view_size);
5083
5084   // Relocate all Cortex-A8 stubs.
5085   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
5086        p != this->cortex_a8_stubs_.end();
5087        ++p)
5088     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
5089                         address, view_size);
5090
5091   // Relocate all ARM V4BX stubs.
5092   for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
5093        p != this->arm_v4bx_stubs_.end();
5094        ++p)
5095     {
5096       if (*p != NULL)
5097         this->relocate_stub(*p, relinfo, arm_target, output_section, view,
5098                             address, view_size);
5099     }
5100 }
5101
5102 // Write out the stubs to file.
5103
5104 template<bool big_endian>
5105 void
5106 Stub_table<big_endian>::do_write(Output_file* of)
5107 {
5108   off_t offset = this->offset();
5109   const section_size_type oview_size =
5110     convert_to_section_size_type(this->data_size());
5111   unsigned char* const oview = of->get_output_view(offset, oview_size);
5112
5113   // Write relocation stubs.
5114   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
5115       p != this->reloc_stubs_.end();
5116       ++p)
5117     {
5118       Reloc_stub* stub = p->second;
5119       Arm_address address = this->address() + stub->offset();
5120       gold_assert(address
5121                   == align_address(address,
5122                                    stub->stub_template()->alignment()));
5123       stub->write(oview + stub->offset(), stub->stub_template()->size(),
5124                   big_endian);
5125     }
5126
5127   // Write Cortex-A8 stubs.
5128   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5129        p != this->cortex_a8_stubs_.end();
5130        ++p)
5131     {
5132       Cortex_a8_stub* stub = p->second;
5133       Arm_address address = this->address() + stub->offset();
5134       gold_assert(address
5135                   == align_address(address,
5136                                    stub->stub_template()->alignment()));
5137       stub->write(oview + stub->offset(), stub->stub_template()->size(),
5138                   big_endian);
5139     }
5140
5141   // Write ARM V4BX relocation stubs.
5142   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5143        p != this->arm_v4bx_stubs_.end();
5144        ++p)
5145     {
5146       if (*p == NULL)
5147         continue;
5148
5149       Arm_address address = this->address() + (*p)->offset();
5150       gold_assert(address
5151                   == align_address(address,
5152                                    (*p)->stub_template()->alignment()));
5153       (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
5154                   big_endian);
5155     }
5156
5157   of->write_output_view(this->offset(), oview_size, oview);
5158 }
5159
5160 // Update the data size and address alignment of the stub table at the end
5161 // of a relaxation pass.   Return true if either the data size or the
5162 // alignment changed in this relaxation pass.
5163
5164 template<bool big_endian>
5165 bool
5166 Stub_table<big_endian>::update_data_size_and_addralign()
5167 {
5168   // Go over all stubs in table to compute data size and address alignment.
5169   off_t size = this->reloc_stubs_size_;
5170   unsigned addralign = this->reloc_stubs_addralign_;
5171
5172   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5173        p != this->cortex_a8_stubs_.end();
5174        ++p)
5175     {
5176       const Stub_template* stub_template = p->second->stub_template();
5177       addralign = std::max(addralign, stub_template->alignment());
5178       size = (align_address(size, stub_template->alignment())
5179               + stub_template->size());
5180     }
5181
5182   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5183        p != this->arm_v4bx_stubs_.end();
5184        ++p)
5185     {
5186       if (*p == NULL)
5187         continue;
5188
5189       const Stub_template* stub_template = (*p)->stub_template();
5190       addralign = std::max(addralign, stub_template->alignment());
5191       size = (align_address(size, stub_template->alignment())
5192               + stub_template->size());
5193     }
5194
5195   // Check if either data size or alignment changed in this pass.
5196   // Update prev_data_size_ and prev_addralign_.  These will be used
5197   // as the current data size and address alignment for the next pass.
5198   bool changed = size != this->prev_data_size_;
5199   this->prev_data_size_ = size;
5200
5201   if (addralign != this->prev_addralign_)
5202     changed = true;
5203   this->prev_addralign_ = addralign;
5204
5205   return changed;
5206 }
5207
5208 // Finalize the stubs.  This sets the offsets of the stubs within the stub
5209 // table.  It also marks all input sections needing Cortex-A8 workaround.
5210
5211 template<bool big_endian>
5212 void
5213 Stub_table<big_endian>::finalize_stubs()
5214 {
5215   off_t off = this->reloc_stubs_size_;
5216   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5217        p != this->cortex_a8_stubs_.end();
5218        ++p)
5219     {
5220       Cortex_a8_stub* stub = p->second;
5221       const Stub_template* stub_template = stub->stub_template();
5222       uint64_t stub_addralign = stub_template->alignment();
5223       off = align_address(off, stub_addralign);
5224       stub->set_offset(off);
5225       off += stub_template->size();
5226
5227       // Mark input section so that we can determine later if a code section
5228       // needs the Cortex-A8 workaround quickly.
5229       Arm_relobj<big_endian>* arm_relobj =
5230         Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5231       arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5232     }
5233
5234   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5235       p != this->arm_v4bx_stubs_.end();
5236       ++p)
5237     {
5238       if (*p == NULL)
5239         continue;
5240
5241       const Stub_template* stub_template = (*p)->stub_template();
5242       uint64_t stub_addralign = stub_template->alignment();
5243       off = align_address(off, stub_addralign);
5244       (*p)->set_offset(off);
5245       off += stub_template->size();
5246     }
5247
5248   gold_assert(off <= this->prev_data_size_);
5249 }
5250
5251 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5252 // and VIEW_ADDRESS + VIEW_SIZE - 1.  VIEW points to the mapped address
5253 // of the address range seen by the linker.
5254
5255 template<bool big_endian>
5256 void
5257 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5258     Target_arm<big_endian>* arm_target,
5259     unsigned char* view,
5260     Arm_address view_address,
5261     section_size_type view_size)
5262 {
5263   // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5264   for (Cortex_a8_stub_list::const_iterator p =
5265          this->cortex_a8_stubs_.lower_bound(view_address);
5266        ((p != this->cortex_a8_stubs_.end())
5267         && (p->first < (view_address + view_size)));
5268        ++p)
5269     {
5270       // We do not store the THUMB bit in the LSB of either the branch address
5271       // or the stub offset.  There is no need to strip the LSB.
5272       Arm_address branch_address = p->first;
5273       const Cortex_a8_stub* stub = p->second;
5274       Arm_address stub_address = this->address() + stub->offset();
5275
5276       // Offset of the branch instruction relative to this view.
5277       section_size_type offset =
5278         convert_to_section_size_type(branch_address - view_address);
5279       gold_assert((offset + 4) <= view_size);
5280
5281       arm_target->apply_cortex_a8_workaround(stub, stub_address,
5282                                              view + offset, branch_address);
5283     }
5284 }
5285
5286 // Arm_input_section methods.
5287
5288 // Initialize an Arm_input_section.
5289
5290 template<bool big_endian>
5291 void
5292 Arm_input_section<big_endian>::init()
5293 {
5294   Relobj* relobj = this->relobj();
5295   unsigned int shndx = this->shndx();
5296
5297   // We have to cache original size, alignment and contents to avoid locking
5298   // the original file.
5299   this->original_addralign_ =
5300     convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5301
5302   // This is not efficient but we expect only a small number of relaxed
5303   // input sections for stubs.
5304   section_size_type section_size;
5305   const unsigned char* section_contents =
5306     relobj->section_contents(shndx, &section_size, false);
5307   this->original_size_ =
5308     convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5309
5310   gold_assert(this->original_contents_ == NULL);
5311   this->original_contents_ = new unsigned char[section_size];
5312   memcpy(this->original_contents_, section_contents, section_size);
5313
5314   // We want to make this look like the original input section after
5315   // output sections are finalized.
5316   Output_section* os = relobj->output_section(shndx);
5317   off_t offset = relobj->output_section_offset(shndx);
5318   gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5319   this->set_address(os->address() + offset);
5320   this->set_file_offset(os->offset() + offset);
5321
5322   this->set_current_data_size(this->original_size_);
5323   this->finalize_data_size();
5324 }
5325
5326 template<bool big_endian>
5327 void
5328 Arm_input_section<big_endian>::do_write(Output_file* of)
5329 {
5330   // We have to write out the original section content.
5331   gold_assert(this->original_contents_ != NULL);
5332   of->write(this->offset(), this->original_contents_,
5333             this->original_size_);
5334
5335   // If this owns a stub table and it is not empty, write it.
5336   if (this->is_stub_table_owner() && !this->stub_table_->empty())
5337     this->stub_table_->write(of);
5338 }
5339
5340 // Finalize data size.
5341
5342 template<bool big_endian>
5343 void
5344 Arm_input_section<big_endian>::set_final_data_size()
5345 {
5346   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5347
5348   if (this->is_stub_table_owner())
5349     {
5350       this->stub_table_->finalize_data_size();
5351       off = align_address(off, this->stub_table_->addralign());
5352       off += this->stub_table_->data_size();
5353     }
5354   this->set_data_size(off);
5355 }
5356
5357 // Reset address and file offset.
5358
5359 template<bool big_endian>
5360 void
5361 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5362 {
5363   // Size of the original input section contents.
5364   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5365
5366   // If this is a stub table owner, account for the stub table size.
5367   if (this->is_stub_table_owner())
5368     {
5369       Stub_table<big_endian>* stub_table = this->stub_table_;
5370
5371       // Reset the stub table's address and file offset.  The
5372       // current data size for child will be updated after that.
5373       stub_table_->reset_address_and_file_offset();
5374       off = align_address(off, stub_table_->addralign());
5375       off += stub_table->current_data_size();
5376     }
5377
5378   this->set_current_data_size(off);
5379 }
5380
5381 // Arm_exidx_cantunwind methods.
5382
5383 // Write this to Output file OF for a fixed endianness.
5384
5385 template<bool big_endian>
5386 void
5387 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5388 {
5389   off_t offset = this->offset();
5390   const section_size_type oview_size = 8;
5391   unsigned char* const oview = of->get_output_view(offset, oview_size);
5392
5393   Output_section* os = this->relobj_->output_section(this->shndx_);
5394   gold_assert(os != NULL);
5395
5396   Arm_relobj<big_endian>* arm_relobj =
5397     Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5398   Arm_address output_offset =
5399     arm_relobj->get_output_section_offset(this->shndx_);
5400   Arm_address section_start;
5401   section_size_type section_size;
5402
5403   // Find out the end of the text section referred by this.
5404   if (output_offset != Arm_relobj<big_endian>::invalid_address)
5405     {
5406       section_start = os->address() + output_offset;
5407       const Arm_exidx_input_section* exidx_input_section =
5408         arm_relobj->exidx_input_section_by_link(this->shndx_);
5409       gold_assert(exidx_input_section != NULL);
5410       section_size =
5411         convert_to_section_size_type(exidx_input_section->text_size());
5412     }
5413   else
5414     {
5415       // Currently this only happens for a relaxed section.
5416       const Output_relaxed_input_section* poris =
5417         os->find_relaxed_input_section(this->relobj_, this->shndx_);
5418       gold_assert(poris != NULL);
5419       section_start = poris->address();
5420       section_size = convert_to_section_size_type(poris->data_size());
5421     }
5422
5423   // We always append this to the end of an EXIDX section.
5424   Arm_address output_address = section_start + section_size;
5425
5426   // Write out the entry.  The first word either points to the beginning
5427   // or after the end of a text section.  The second word is the special
5428   // EXIDX_CANTUNWIND value.
5429   uint32_t prel31_offset = output_address - this->address();
5430   if (Bits<31>::has_overflow32(offset))
5431     gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5432   elfcpp::Swap_unaligned<32, big_endian>::writeval(oview,
5433                                                    prel31_offset & 0x7fffffffU);
5434   elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4,
5435                                                    elfcpp::EXIDX_CANTUNWIND);
5436
5437   of->write_output_view(this->offset(), oview_size, oview);
5438 }
5439
5440 // Arm_exidx_merged_section methods.
5441
5442 // Constructor for Arm_exidx_merged_section.
5443 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5444 // SECTION_OFFSET_MAP points to a section offset map describing how
5445 // parts of the input section are mapped to output.  DELETED_BYTES is
5446 // the number of bytes deleted from the EXIDX input section.
5447
5448 Arm_exidx_merged_section::Arm_exidx_merged_section(
5449     const Arm_exidx_input_section& exidx_input_section,
5450     const Arm_exidx_section_offset_map& section_offset_map,
5451     uint32_t deleted_bytes)
5452   : Output_relaxed_input_section(exidx_input_section.relobj(),
5453                                  exidx_input_section.shndx(),
5454                                  exidx_input_section.addralign()),
5455     exidx_input_section_(exidx_input_section),
5456     section_offset_map_(section_offset_map)
5457 {
5458   // If we retain or discard the whole EXIDX input section,  we would
5459   // not be here.
5460   gold_assert(deleted_bytes != 0
5461               && deleted_bytes != this->exidx_input_section_.size());
5462
5463   // Fix size here so that we do not need to implement set_final_data_size.
5464   uint32_t size = exidx_input_section.size() - deleted_bytes;
5465   this->set_data_size(size);
5466   this->fix_data_size();
5467
5468   // Allocate buffer for section contents and build contents.
5469   this->section_contents_ = new unsigned char[size];
5470 }
5471
5472 // Build the contents of a merged EXIDX output section.
5473
5474 void
5475 Arm_exidx_merged_section::build_contents(
5476     const unsigned char* original_contents,
5477     section_size_type original_size)
5478 {
5479   // Go over spans of input offsets and write only those that are not
5480   // discarded.
5481   section_offset_type in_start = 0;
5482   section_offset_type out_start = 0;
5483   section_offset_type in_max =
5484     convert_types<section_offset_type>(original_size);
5485   section_offset_type out_max =
5486     convert_types<section_offset_type>(this->data_size());
5487   for (Arm_exidx_section_offset_map::const_iterator p =
5488         this->section_offset_map_.begin();
5489       p != this->section_offset_map_.end();
5490       ++p)
5491     {
5492       section_offset_type in_end = p->first;
5493       gold_assert(in_end >= in_start);
5494       section_offset_type out_end = p->second;
5495       size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5496       if (out_end != -1)
5497         {
5498           size_t out_chunk_size =
5499             convert_types<size_t>(out_end - out_start + 1);
5500
5501           gold_assert(out_chunk_size == in_chunk_size
5502                       && in_end < in_max && out_end < out_max);
5503
5504           memcpy(this->section_contents_ + out_start,
5505                  original_contents + in_start,
5506                  out_chunk_size);
5507           out_start += out_chunk_size;
5508         }
5509       in_start += in_chunk_size;
5510     }
5511 }
5512
5513 // Given an input OBJECT, an input section index SHNDX within that
5514 // object, and an OFFSET relative to the start of that input
5515 // section, return whether or not the corresponding offset within
5516 // the output section is known.  If this function returns true, it
5517 // sets *POUTPUT to the output offset.  The value -1 indicates that
5518 // this input offset is being discarded.
5519
5520 bool
5521 Arm_exidx_merged_section::do_output_offset(
5522     const Relobj* relobj,
5523     unsigned int shndx,
5524     section_offset_type offset,
5525     section_offset_type* poutput) const
5526 {
5527   // We only handle offsets for the original EXIDX input section.
5528   if (relobj != this->exidx_input_section_.relobj()
5529       || shndx != this->exidx_input_section_.shndx())
5530     return false;
5531
5532   section_offset_type section_size =
5533     convert_types<section_offset_type>(this->exidx_input_section_.size());
5534   if (offset < 0 || offset >= section_size)
5535     // Input offset is out of valid range.
5536     *poutput = -1;
5537   else
5538     {
5539       // We need to look up the section offset map to determine the output
5540       // offset.  Find the reference point in map that is first offset
5541       // bigger than or equal to this offset.
5542       Arm_exidx_section_offset_map::const_iterator p =
5543         this->section_offset_map_.lower_bound(offset);
5544
5545       // The section offset maps are build such that this should not happen if
5546       // input offset is in the valid range.
5547       gold_assert(p != this->section_offset_map_.end());
5548
5549       // We need to check if this is dropped.
5550      section_offset_type ref = p->first;
5551      section_offset_type mapped_ref = p->second;
5552
5553       if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5554         // Offset is present in output.
5555         *poutput = mapped_ref + (offset - ref);
5556       else
5557         // Offset is discarded owing to EXIDX entry merging.
5558         *poutput = -1;
5559     }
5560
5561   return true;
5562 }
5563
5564 // Write this to output file OF.
5565
5566 void
5567 Arm_exidx_merged_section::do_write(Output_file* of)
5568 {
5569   off_t offset = this->offset();
5570   const section_size_type oview_size = this->data_size();
5571   unsigned char* const oview = of->get_output_view(offset, oview_size);
5572
5573   Output_section* os = this->relobj()->output_section(this->shndx());
5574   gold_assert(os != NULL);
5575
5576   memcpy(oview, this->section_contents_, oview_size);
5577   of->write_output_view(this->offset(), oview_size, oview);
5578 }
5579
5580 // Arm_exidx_fixup methods.
5581
5582 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5583 // is not an EXIDX_CANTUNWIND entry already.  The new EXIDX_CANTUNWIND entry
5584 // points to the end of the last seen EXIDX section.
5585
5586 void
5587 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5588 {
5589   if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5590       && this->last_input_section_ != NULL)
5591     {
5592       Relobj* relobj = this->last_input_section_->relobj();
5593       unsigned int text_shndx = this->last_input_section_->link();
5594       Arm_exidx_cantunwind* cantunwind =
5595         new Arm_exidx_cantunwind(relobj, text_shndx);
5596       this->exidx_output_section_->add_output_section_data(cantunwind);
5597       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5598     }
5599 }
5600
5601 // Process an EXIDX section entry in input.  Return whether this entry
5602 // can be deleted in the output.  SECOND_WORD in the second word of the
5603 // EXIDX entry.
5604
5605 bool
5606 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5607 {
5608   bool delete_entry;
5609   if (second_word == elfcpp::EXIDX_CANTUNWIND)
5610     {
5611       // Merge if previous entry is also an EXIDX_CANTUNWIND.
5612       delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5613       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5614     }
5615   else if ((second_word & 0x80000000) != 0)
5616     {
5617       // Inlined unwinding data.  Merge if equal to previous.
5618       delete_entry = (merge_exidx_entries_
5619                       && this->last_unwind_type_ == UT_INLINED_ENTRY
5620                       && this->last_inlined_entry_ == second_word);
5621       this->last_unwind_type_ = UT_INLINED_ENTRY;
5622       this->last_inlined_entry_ = second_word;
5623     }
5624   else
5625     {
5626       // Normal table entry.  In theory we could merge these too,
5627       // but duplicate entries are likely to be much less common.
5628       delete_entry = false;
5629       this->last_unwind_type_ = UT_NORMAL_ENTRY;
5630     }
5631   return delete_entry;
5632 }
5633
5634 // Update the current section offset map during EXIDX section fix-up.
5635 // If there is no map, create one.  INPUT_OFFSET is the offset of a
5636 // reference point, DELETED_BYTES is the number of deleted by in the
5637 // section so far.  If DELETE_ENTRY is true, the reference point and
5638 // all offsets after the previous reference point are discarded.
5639
5640 void
5641 Arm_exidx_fixup::update_offset_map(
5642     section_offset_type input_offset,
5643     section_size_type deleted_bytes,
5644     bool delete_entry)
5645 {
5646   if (this->section_offset_map_ == NULL)
5647     this->section_offset_map_ = new Arm_exidx_section_offset_map();
5648   section_offset_type output_offset;
5649   if (delete_entry)
5650     output_offset = Arm_exidx_input_section::invalid_offset;
5651   else
5652     output_offset = input_offset - deleted_bytes;
5653   (*this->section_offset_map_)[input_offset] = output_offset;
5654 }
5655
5656 // Process EXIDX_INPUT_SECTION for EXIDX entry merging.  Return the number of
5657 // bytes deleted.  SECTION_CONTENTS points to the contents of the EXIDX
5658 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5659 // If some entries are merged, also store a pointer to a newly created
5660 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP.  The caller
5661 // owns the map and is responsible for releasing it after use.
5662
5663 template<bool big_endian>
5664 uint32_t
5665 Arm_exidx_fixup::process_exidx_section(
5666     const Arm_exidx_input_section* exidx_input_section,
5667     const unsigned char* section_contents,
5668     section_size_type section_size,
5669     Arm_exidx_section_offset_map** psection_offset_map)
5670 {
5671   Relobj* relobj = exidx_input_section->relobj();
5672   unsigned shndx = exidx_input_section->shndx();
5673
5674   if ((section_size % 8) != 0)
5675     {
5676       // Something is wrong with this section.  Better not touch it.
5677       gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5678                  relobj->name().c_str(), shndx);
5679       this->last_input_section_ = exidx_input_section;
5680       this->last_unwind_type_ = UT_NONE;
5681       return 0;
5682     }
5683
5684   uint32_t deleted_bytes = 0;
5685   bool prev_delete_entry = false;
5686   gold_assert(this->section_offset_map_ == NULL);
5687
5688   for (section_size_type i = 0; i < section_size; i += 8)
5689     {
5690       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5691       const Valtype* wv =
5692           reinterpret_cast<const Valtype*>(section_contents + i + 4);
5693       uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5694
5695       bool delete_entry = this->process_exidx_entry(second_word);
5696
5697       // Entry deletion causes changes in output offsets.  We use a std::map
5698       // to record these.  And entry (x, y) means input offset x
5699       // is mapped to output offset y.  If y is invalid_offset, then x is
5700       // dropped in the output.  Because of the way std::map::lower_bound
5701       // works, we record the last offset in a region w.r.t to keeping or
5702       // dropping.  If there is no entry (x0, y0) for an input offset x0,
5703       // the output offset y0 of it is determined by the output offset y1 of
5704       // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5705       // in the map.  If y1 is not -1, then y0 = y1 + x0 - x1.  Otherwise, y1
5706       // y0 is also -1.
5707       if (delete_entry != prev_delete_entry && i != 0)
5708         this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5709
5710       // Update total deleted bytes for this entry.
5711       if (delete_entry)
5712         deleted_bytes += 8;
5713
5714       prev_delete_entry = delete_entry;
5715     }
5716
5717   // If section offset map is not NULL, make an entry for the end of
5718   // section.
5719   if (this->section_offset_map_ != NULL)
5720     update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5721
5722   *psection_offset_map = this->section_offset_map_;
5723   this->section_offset_map_ = NULL;
5724   this->last_input_section_ = exidx_input_section;
5725
5726   // Set the first output text section so that we can link the EXIDX output
5727   // section to it.  Ignore any EXIDX input section that is completely merged.
5728   if (this->first_output_text_section_ == NULL
5729       && deleted_bytes != section_size)
5730     {
5731       unsigned int link = exidx_input_section->link();
5732       Output_section* os = relobj->output_section(link);
5733       gold_assert(os != NULL);
5734       this->first_output_text_section_ = os;
5735     }
5736
5737   return deleted_bytes;
5738 }
5739
5740 // Arm_output_section methods.
5741
5742 // Create a stub group for input sections from BEGIN to END.  OWNER
5743 // points to the input section to be the owner a new stub table.
5744
5745 template<bool big_endian>
5746 void
5747 Arm_output_section<big_endian>::create_stub_group(
5748   Input_section_list::const_iterator begin,
5749   Input_section_list::const_iterator end,
5750   Input_section_list::const_iterator owner,
5751   Target_arm<big_endian>* target,
5752   std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5753   const Task* task)
5754 {
5755   // We use a different kind of relaxed section in an EXIDX section.
5756   // The static casting from Output_relaxed_input_section to
5757   // Arm_input_section is invalid in an EXIDX section.  We are okay
5758   // because we should not be calling this for an EXIDX section.
5759   gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5760
5761   // Currently we convert ordinary input sections into relaxed sections only
5762   // at this point but we may want to support creating relaxed input section
5763   // very early.  So we check here to see if owner is already a relaxed
5764   // section.
5765
5766   Arm_input_section<big_endian>* arm_input_section;
5767   if (owner->is_relaxed_input_section())
5768     {
5769       arm_input_section =
5770         Arm_input_section<big_endian>::as_arm_input_section(
5771           owner->relaxed_input_section());
5772     }
5773   else
5774     {
5775       gold_assert(owner->is_input_section());
5776       // Create a new relaxed input section.  We need to lock the original
5777       // file.
5778       Task_lock_obj<Object> tl(task, owner->relobj());
5779       arm_input_section =
5780         target->new_arm_input_section(owner->relobj(), owner->shndx());
5781       new_relaxed_sections->push_back(arm_input_section);
5782     }
5783
5784   // Create a stub table.
5785   Stub_table<big_endian>* stub_table =
5786     target->new_stub_table(arm_input_section);
5787
5788   arm_input_section->set_stub_table(stub_table);
5789
5790   Input_section_list::const_iterator p = begin;
5791   Input_section_list::const_iterator prev_p;
5792
5793   // Look for input sections or relaxed input sections in [begin ... end].
5794   do
5795     {
5796       if (p->is_input_section() || p->is_relaxed_input_section())
5797         {
5798           // The stub table information for input sections live
5799           // in their objects.
5800           Arm_relobj<big_endian>* arm_relobj =
5801             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5802           arm_relobj->set_stub_table(p->shndx(), stub_table);
5803         }
5804       prev_p = p++;
5805     }
5806   while (prev_p != end);
5807 }
5808
5809 // Group input sections for stub generation.  GROUP_SIZE is roughly the limit
5810 // of stub groups.  We grow a stub group by adding input section until the
5811 // size is just below GROUP_SIZE.  The last input section will be converted
5812 // into a stub table.  If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5813 // input section after the stub table, effectively double the group size.
5814 //
5815 // This is similar to the group_sections() function in elf32-arm.c but is
5816 // implemented differently.
5817
5818 template<bool big_endian>
5819 void
5820 Arm_output_section<big_endian>::group_sections(
5821     section_size_type group_size,
5822     bool stubs_always_after_branch,
5823     Target_arm<big_endian>* target,
5824     const Task* task)
5825 {
5826   // States for grouping.
5827   typedef enum
5828   {
5829     // No group is being built.
5830     NO_GROUP,
5831     // A group is being built but the stub table is not found yet.
5832     // We keep group a stub group until the size is just under GROUP_SIZE.
5833     // The last input section in the group will be used as the stub table.
5834     FINDING_STUB_SECTION,
5835     // A group is being built and we have already found a stub table.
5836     // We enter this state to grow a stub group by adding input section
5837     // after the stub table.  This effectively doubles the group size.
5838     HAS_STUB_SECTION
5839   } State;
5840
5841   // Any newly created relaxed sections are stored here.
5842   std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5843
5844   State state = NO_GROUP;
5845   section_size_type off = 0;
5846   section_size_type group_begin_offset = 0;
5847   section_size_type group_end_offset = 0;
5848   section_size_type stub_table_end_offset = 0;
5849   Input_section_list::const_iterator group_begin =
5850     this->input_sections().end();
5851   Input_section_list::const_iterator stub_table =
5852     this->input_sections().end();
5853   Input_section_list::const_iterator group_end = this->input_sections().end();
5854   for (Input_section_list::const_iterator p = this->input_sections().begin();
5855        p != this->input_sections().end();
5856        ++p)
5857     {
5858       section_size_type section_begin_offset =
5859         align_address(off, p->addralign());
5860       section_size_type section_end_offset =
5861         section_begin_offset + p->data_size();
5862
5863       // Check to see if we should group the previously seen sections.
5864       switch (state)
5865         {
5866         case NO_GROUP:
5867           break;
5868
5869         case FINDING_STUB_SECTION:
5870           // Adding this section makes the group larger than GROUP_SIZE.
5871           if (section_end_offset - group_begin_offset >= group_size)
5872             {
5873               if (stubs_always_after_branch)
5874                 {
5875                   gold_assert(group_end != this->input_sections().end());
5876                   this->create_stub_group(group_begin, group_end, group_end,
5877                                           target, &new_relaxed_sections,
5878                                           task);
5879                   state = NO_GROUP;
5880                 }
5881               else
5882                 {
5883                   // But wait, there's more!  Input sections up to
5884                   // stub_group_size bytes after the stub table can be
5885                   // handled by it too.
5886                   state = HAS_STUB_SECTION;
5887                   stub_table = group_end;
5888                   stub_table_end_offset = group_end_offset;
5889                 }
5890             }
5891             break;
5892
5893         case HAS_STUB_SECTION:
5894           // Adding this section makes the post stub-section group larger
5895           // than GROUP_SIZE.
5896           if (section_end_offset - stub_table_end_offset >= group_size)
5897            {
5898              gold_assert(group_end != this->input_sections().end());
5899              this->create_stub_group(group_begin, group_end, stub_table,
5900                                      target, &new_relaxed_sections, task);
5901              state = NO_GROUP;
5902            }
5903            break;
5904
5905           default:
5906             gold_unreachable();
5907         }
5908
5909       // If we see an input section and currently there is no group, start
5910       // a new one.  Skip any empty sections.  We look at the data size
5911       // instead of calling p->relobj()->section_size() to avoid locking.
5912       if ((p->is_input_section() || p->is_relaxed_input_section())
5913           && (p->data_size() != 0))
5914         {
5915           if (state == NO_GROUP)
5916             {
5917               state = FINDING_STUB_SECTION;
5918               group_begin = p;
5919               group_begin_offset = section_begin_offset;
5920             }
5921
5922           // Keep track of the last input section seen.
5923           group_end = p;
5924           group_end_offset = section_end_offset;
5925         }
5926
5927       off = section_end_offset;
5928     }
5929
5930   // Create a stub group for any ungrouped sections.
5931   if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5932     {
5933       gold_assert(group_end != this->input_sections().end());
5934       this->create_stub_group(group_begin, group_end,
5935                               (state == FINDING_STUB_SECTION
5936                                ? group_end
5937                                : stub_table),
5938                                target, &new_relaxed_sections, task);
5939     }
5940
5941   // Convert input section into relaxed input section in a batch.
5942   if (!new_relaxed_sections.empty())
5943     this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5944
5945   // Update the section offsets
5946   for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5947     {
5948       Arm_relobj<big_endian>* arm_relobj =
5949         Arm_relobj<big_endian>::as_arm_relobj(
5950           new_relaxed_sections[i]->relobj());
5951       unsigned int shndx = new_relaxed_sections[i]->shndx();
5952       // Tell Arm_relobj that this input section is converted.
5953       arm_relobj->convert_input_section_to_relaxed_section(shndx);
5954     }
5955 }
5956
5957 // Append non empty text sections in this to LIST in ascending
5958 // order of their position in this.
5959
5960 template<bool big_endian>
5961 void
5962 Arm_output_section<big_endian>::append_text_sections_to_list(
5963     Text_section_list* list)
5964 {
5965   gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5966
5967   for (Input_section_list::const_iterator p = this->input_sections().begin();
5968        p != this->input_sections().end();
5969        ++p)
5970     {
5971       // We only care about plain or relaxed input sections.  We also
5972       // ignore any merged sections.
5973       if (p->is_input_section() || p->is_relaxed_input_section())
5974         list->push_back(Text_section_list::value_type(p->relobj(),
5975                                                       p->shndx()));
5976     }
5977 }
5978
5979 template<bool big_endian>
5980 void
5981 Arm_output_section<big_endian>::fix_exidx_coverage(
5982     Layout* layout,
5983     const Text_section_list& sorted_text_sections,
5984     Symbol_table* symtab,
5985     bool merge_exidx_entries,
5986     const Task* task)
5987 {
5988   // We should only do this for the EXIDX output section.
5989   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5990
5991   // We don't want the relaxation loop to undo these changes, so we discard
5992   // the current saved states and take another one after the fix-up.
5993   this->discard_states();
5994
5995   // Remove all input sections.
5996   uint64_t address = this->address();
5997   typedef std::list<Output_section::Input_section> Input_section_list;
5998   Input_section_list input_sections;
5999   this->reset_address_and_file_offset();
6000   this->get_input_sections(address, std::string(""), &input_sections);
6001
6002   if (!this->input_sections().empty())
6003     gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
6004
6005   // Go through all the known input sections and record them.
6006   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
6007   typedef Unordered_map<Section_id, const Output_section::Input_section*,
6008                         Section_id_hash> Text_to_exidx_map;
6009   Text_to_exidx_map text_to_exidx_map;
6010   for (Input_section_list::const_iterator p = input_sections.begin();
6011        p != input_sections.end();
6012        ++p)
6013     {
6014       // This should never happen.  At this point, we should only see
6015       // plain EXIDX input sections.
6016       gold_assert(!p->is_relaxed_input_section());
6017       text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
6018     }
6019
6020   Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
6021
6022   // Go over the sorted text sections.
6023   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
6024   Section_id_set processed_input_sections;
6025   for (Text_section_list::const_iterator p = sorted_text_sections.begin();
6026        p != sorted_text_sections.end();
6027        ++p)
6028     {
6029       Relobj* relobj = p->first;
6030       unsigned int shndx = p->second;
6031
6032       Arm_relobj<big_endian>* arm_relobj =
6033          Arm_relobj<big_endian>::as_arm_relobj(relobj);
6034       const Arm_exidx_input_section* exidx_input_section =
6035          arm_relobj->exidx_input_section_by_link(shndx);
6036
6037       // If this text section has no EXIDX section or if the EXIDX section
6038       // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
6039       // of the last seen EXIDX section.
6040       if (exidx_input_section == NULL || exidx_input_section->has_errors())
6041         {
6042           exidx_fixup.add_exidx_cantunwind_as_needed();
6043           continue;
6044         }
6045
6046       Relobj* exidx_relobj = exidx_input_section->relobj();
6047       unsigned int exidx_shndx = exidx_input_section->shndx();
6048       Section_id sid(exidx_relobj, exidx_shndx);
6049       Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
6050       if (iter == text_to_exidx_map.end())
6051         {
6052           // This is odd.  We have not seen this EXIDX input section before.
6053           // We cannot do fix-up.  If we saw a SECTIONS clause in a script,
6054           // issue a warning instead.  We assume the user knows what he
6055           // or she is doing.  Otherwise, this is an error.
6056           if (layout->script_options()->saw_sections_clause())
6057             gold_warning(_("unwinding may not work because EXIDX input section"
6058                            " %u of %s is not in EXIDX output section"),
6059                          exidx_shndx, exidx_relobj->name().c_str());
6060           else
6061             gold_error(_("unwinding may not work because EXIDX input section"
6062                          " %u of %s is not in EXIDX output section"),
6063                        exidx_shndx, exidx_relobj->name().c_str());
6064
6065           exidx_fixup.add_exidx_cantunwind_as_needed();
6066           continue;
6067         }
6068
6069       // We need to access the contents of the EXIDX section, lock the
6070       // object here.
6071       Task_lock_obj<Object> tl(task, exidx_relobj);
6072       section_size_type exidx_size;
6073       const unsigned char* exidx_contents =
6074         exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
6075
6076       // Fix up coverage and append input section to output data list.
6077       Arm_exidx_section_offset_map* section_offset_map = NULL;
6078       uint32_t deleted_bytes =
6079         exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
6080                                                       exidx_contents,
6081                                                       exidx_size,
6082                                                       &section_offset_map);
6083
6084       if (deleted_bytes == exidx_input_section->size())
6085         {
6086           // The whole EXIDX section got merged.  Remove it from output.
6087           gold_assert(section_offset_map == NULL);
6088           exidx_relobj->set_output_section(exidx_shndx, NULL);
6089
6090           // All local symbols defined in this input section will be dropped.
6091           // We need to adjust output local symbol count.
6092           arm_relobj->set_output_local_symbol_count_needs_update();
6093         }
6094       else if (deleted_bytes > 0)
6095         {
6096           // Some entries are merged.  We need to convert this EXIDX input
6097           // section into a relaxed section.
6098           gold_assert(section_offset_map != NULL);
6099
6100           Arm_exidx_merged_section* merged_section =
6101             new Arm_exidx_merged_section(*exidx_input_section,
6102                                          *section_offset_map, deleted_bytes);
6103           merged_section->build_contents(exidx_contents, exidx_size);
6104
6105           const std::string secname = exidx_relobj->section_name(exidx_shndx);
6106           this->add_relaxed_input_section(layout, merged_section, secname);
6107           arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
6108
6109           // All local symbols defined in discarded portions of this input
6110           // section will be dropped.  We need to adjust output local symbol
6111           // count.
6112           arm_relobj->set_output_local_symbol_count_needs_update();
6113         }
6114       else
6115         {
6116           // Just add back the EXIDX input section.
6117           gold_assert(section_offset_map == NULL);
6118           const Output_section::Input_section* pis = iter->second;
6119           gold_assert(pis->is_input_section());
6120           this->add_script_input_section(*pis);
6121         }
6122
6123       processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
6124     }
6125
6126   // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
6127   exidx_fixup.add_exidx_cantunwind_as_needed();
6128
6129   // Remove any known EXIDX input sections that are not processed.
6130   for (Input_section_list::const_iterator p = input_sections.begin();
6131        p != input_sections.end();
6132        ++p)
6133     {
6134       if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
6135           == processed_input_sections.end())
6136         {
6137           // We discard a known EXIDX section because its linked
6138           // text section has been folded by ICF.  We also discard an
6139           // EXIDX section with error, the output does not matter in this
6140           // case.  We do this to avoid triggering asserts.
6141           Arm_relobj<big_endian>* arm_relobj =
6142             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6143           const Arm_exidx_input_section* exidx_input_section =
6144             arm_relobj->exidx_input_section_by_shndx(p->shndx());
6145           gold_assert(exidx_input_section != NULL);
6146           if (!exidx_input_section->has_errors())
6147             {
6148               unsigned int text_shndx = exidx_input_section->link();
6149               gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
6150             }
6151
6152           // Remove this from link.  We also need to recount the
6153           // local symbols.
6154           p->relobj()->set_output_section(p->shndx(), NULL);
6155           arm_relobj->set_output_local_symbol_count_needs_update();
6156         }
6157     }
6158
6159   // Link exidx output section to the first seen output section and
6160   // set correct entry size.
6161   this->set_link_section(exidx_fixup.first_output_text_section());
6162   this->set_entsize(8);
6163
6164   // Make changes permanent.
6165   this->save_states();
6166   this->set_section_offsets_need_adjustment();
6167 }
6168
6169 // Link EXIDX output sections to text output sections.
6170
6171 template<bool big_endian>
6172 void
6173 Arm_output_section<big_endian>::set_exidx_section_link()
6174 {
6175   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
6176   if (!this->input_sections().empty())
6177     {
6178       Input_section_list::const_iterator p = this->input_sections().begin();
6179       Arm_relobj<big_endian>* arm_relobj =
6180         Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6181       unsigned exidx_shndx = p->shndx();
6182       const Arm_exidx_input_section* exidx_input_section =
6183         arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6184       gold_assert(exidx_input_section != NULL);
6185       unsigned int text_shndx = exidx_input_section->link();
6186       Output_section* os = arm_relobj->output_section(text_shndx);
6187       this->set_link_section(os);
6188     }
6189 }
6190
6191 // Arm_relobj methods.
6192
6193 // Determine if an input section is scannable for stub processing.  SHDR is
6194 // the header of the section and SHNDX is the section index.  OS is the output
6195 // section for the input section and SYMTAB is the global symbol table used to
6196 // look up ICF information.
6197
6198 template<bool big_endian>
6199 bool
6200 Arm_relobj<big_endian>::section_is_scannable(
6201     const elfcpp::Shdr<32, big_endian>& shdr,
6202     unsigned int shndx,
6203     const Output_section* os,
6204     const Symbol_table* symtab)
6205 {
6206   // Skip any empty sections, unallocated sections or sections whose
6207   // type are not SHT_PROGBITS.
6208   if (shdr.get_sh_size() == 0
6209       || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6210       || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6211     return false;
6212
6213   // Skip any discarded or ICF'ed sections.
6214   if (os == NULL || symtab->is_section_folded(this, shndx))
6215     return false;
6216
6217   // If this requires special offset handling, check to see if it is
6218   // a relaxed section.  If this is not, then it is a merged section that
6219   // we cannot handle.
6220   if (this->is_output_section_offset_invalid(shndx))
6221     {
6222       const Output_relaxed_input_section* poris =
6223         os->find_relaxed_input_section(this, shndx);
6224       if (poris == NULL)
6225         return false;
6226     }
6227
6228   return true;
6229 }
6230
6231 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6232 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6233
6234 template<bool big_endian>
6235 bool
6236 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6237     const elfcpp::Shdr<32, big_endian>& shdr,
6238     const Relobj::Output_sections& out_sections,
6239     const Symbol_table* symtab,
6240     const unsigned char* pshdrs)
6241 {
6242   unsigned int sh_type = shdr.get_sh_type();
6243   if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6244     return false;
6245
6246   // Ignore empty section.
6247   off_t sh_size = shdr.get_sh_size();
6248   if (sh_size == 0)
6249     return false;
6250
6251   // Ignore reloc section with unexpected symbol table.  The
6252   // error will be reported in the final link.
6253   if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6254     return false;
6255
6256   unsigned int reloc_size;
6257   if (sh_type == elfcpp::SHT_REL)
6258     reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6259   else
6260     reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6261
6262   // Ignore reloc section with unexpected entsize or uneven size.
6263   // The error will be reported in the final link.
6264   if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6265     return false;
6266
6267   // Ignore reloc section with bad info.  This error will be
6268   // reported in the final link.
6269   unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6270   if (index >= this->shnum())
6271     return false;
6272
6273   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6274   const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6275   return this->section_is_scannable(text_shdr, index,
6276                                    out_sections[index], symtab);
6277 }
6278
6279 // Return the output address of either a plain input section or a relaxed
6280 // input section.  SHNDX is the section index.  We define and use this
6281 // instead of calling Output_section::output_address because that is slow
6282 // for large output.
6283
6284 template<bool big_endian>
6285 Arm_address
6286 Arm_relobj<big_endian>::simple_input_section_output_address(
6287     unsigned int shndx,
6288     Output_section* os)
6289 {
6290   if (this->is_output_section_offset_invalid(shndx))
6291     {
6292       const Output_relaxed_input_section* poris =
6293         os->find_relaxed_input_section(this, shndx);
6294       // We do not handle merged sections here.
6295       gold_assert(poris != NULL);
6296       return poris->address();
6297     }
6298   else
6299     return os->address() + this->get_output_section_offset(shndx);
6300 }
6301
6302 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6303 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6304
6305 template<bool big_endian>
6306 bool
6307 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6308     const elfcpp::Shdr<32, big_endian>& shdr,
6309     unsigned int shndx,
6310     Output_section* os,
6311     const Symbol_table* symtab)
6312 {
6313   if (!this->section_is_scannable(shdr, shndx, os, symtab))
6314     return false;
6315
6316   // If the section does not cross any 4K-boundaries, it does not need to
6317   // be scanned.
6318   Arm_address address = this->simple_input_section_output_address(shndx, os);
6319   if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6320     return false;
6321
6322   return true;
6323 }
6324
6325 // Scan a section for Cortex-A8 workaround.
6326
6327 template<bool big_endian>
6328 void
6329 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6330     const elfcpp::Shdr<32, big_endian>& shdr,
6331     unsigned int shndx,
6332     Output_section* os,
6333     Target_arm<big_endian>* arm_target)
6334 {
6335   // Look for the first mapping symbol in this section.  It should be
6336   // at (shndx, 0).
6337   Mapping_symbol_position section_start(shndx, 0);
6338   typename Mapping_symbols_info::const_iterator p =
6339     this->mapping_symbols_info_.lower_bound(section_start);
6340
6341   // There are no mapping symbols for this section.  Treat it as a data-only
6342   // section.
6343   if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6344     return;
6345
6346   Arm_address output_address =
6347     this->simple_input_section_output_address(shndx, os);
6348
6349   // Get the section contents.
6350   section_size_type input_view_size = 0;
6351   const unsigned char* input_view =
6352     this->section_contents(shndx, &input_view_size, false);
6353
6354   // We need to go through the mapping symbols to determine what to
6355   // scan.  There are two reasons.  First, we should look at THUMB code and
6356   // THUMB code only.  Second, we only want to look at the 4K-page boundary
6357   // to speed up the scanning.
6358
6359   while (p != this->mapping_symbols_info_.end()
6360         && p->first.first == shndx)
6361     {
6362       typename Mapping_symbols_info::const_iterator next =
6363         this->mapping_symbols_info_.upper_bound(p->first);
6364
6365       // Only scan part of a section with THUMB code.
6366       if (p->second == 't')
6367         {
6368           // Determine the end of this range.
6369           section_size_type span_start =
6370             convert_to_section_size_type(p->first.second);
6371           section_size_type span_end;
6372           if (next != this->mapping_symbols_info_.end()
6373               && next->first.first == shndx)
6374             span_end = convert_to_section_size_type(next->first.second);
6375           else
6376             span_end = convert_to_section_size_type(shdr.get_sh_size());
6377
6378           if (((span_start + output_address) & ~0xfffUL)
6379               != ((span_end + output_address - 1) & ~0xfffUL))
6380             {
6381               arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6382                                                           span_start, span_end,
6383                                                           input_view,
6384                                                           output_address);
6385             }
6386         }
6387
6388       p = next;
6389     }
6390 }
6391
6392 // Scan relocations for stub generation.
6393
6394 template<bool big_endian>
6395 void
6396 Arm_relobj<big_endian>::scan_sections_for_stubs(
6397     Target_arm<big_endian>* arm_target,
6398     const Symbol_table* symtab,
6399     const Layout* layout)
6400 {
6401   unsigned int shnum = this->shnum();
6402   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6403
6404   // Read the section headers.
6405   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6406                                                shnum * shdr_size,
6407                                                true, true);
6408
6409   // To speed up processing, we set up hash tables for fast lookup of
6410   // input offsets to output addresses.
6411   this->initialize_input_to_output_maps();
6412
6413   const Relobj::Output_sections& out_sections(this->output_sections());
6414
6415   Relocate_info<32, big_endian> relinfo;
6416   relinfo.symtab = symtab;
6417   relinfo.layout = layout;
6418   relinfo.object = this;
6419
6420   // Do relocation stubs scanning.
6421   const unsigned char* p = pshdrs + shdr_size;
6422   for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6423     {
6424       const elfcpp::Shdr<32, big_endian> shdr(p);
6425       if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6426                                                   pshdrs))
6427         {
6428           unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6429           Arm_address output_offset = this->get_output_section_offset(index);
6430           Arm_address output_address;
6431           if (output_offset != invalid_address)
6432             output_address = out_sections[index]->address() + output_offset;
6433           else
6434             {
6435               // Currently this only happens for a relaxed section.
6436               const Output_relaxed_input_section* poris =
6437               out_sections[index]->find_relaxed_input_section(this, index);
6438               gold_assert(poris != NULL);
6439               output_address = poris->address();
6440             }
6441
6442           // Get the relocations.
6443           const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6444                                                         shdr.get_sh_size(),
6445                                                         true, false);
6446
6447           // Get the section contents.  This does work for the case in which
6448           // we modify the contents of an input section.  We need to pass the
6449           // output view under such circumstances.
6450           section_size_type input_view_size = 0;
6451           const unsigned char* input_view =
6452             this->section_contents(index, &input_view_size, false);
6453
6454           relinfo.reloc_shndx = i;
6455           relinfo.data_shndx = index;
6456           unsigned int sh_type = shdr.get_sh_type();
6457           unsigned int reloc_size;
6458           if (sh_type == elfcpp::SHT_REL)
6459             reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6460           else
6461             reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6462
6463           Output_section* os = out_sections[index];
6464           arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6465                                              shdr.get_sh_size() / reloc_size,
6466                                              os,
6467                                              output_offset == invalid_address,
6468                                              input_view, output_address,
6469                                              input_view_size);
6470         }
6471     }
6472
6473   // Do Cortex-A8 erratum stubs scanning.  This has to be done for a section
6474   // after its relocation section, if there is one, is processed for
6475   // relocation stubs.  Merging this loop with the one above would have been
6476   // complicated since we would have had to make sure that relocation stub
6477   // scanning is done first.
6478   if (arm_target->fix_cortex_a8())
6479     {
6480       const unsigned char* p = pshdrs + shdr_size;
6481       for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6482         {
6483           const elfcpp::Shdr<32, big_endian> shdr(p);
6484           if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6485                                                           out_sections[i],
6486                                                           symtab))
6487             this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6488                                                      arm_target);
6489         }
6490     }
6491
6492   // After we've done the relocations, we release the hash tables,
6493   // since we no longer need them.
6494   this->free_input_to_output_maps();
6495 }
6496
6497 // Count the local symbols.  The ARM backend needs to know if a symbol
6498 // is a THUMB function or not.  For global symbols, it is easy because
6499 // the Symbol object keeps the ELF symbol type.  For local symbol it is
6500 // harder because we cannot access this information.   So we override the
6501 // do_count_local_symbol in parent and scan local symbols to mark
6502 // THUMB functions.  This is not the most efficient way but I do not want to
6503 // slow down other ports by calling a per symbol target hook inside
6504 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6505
6506 template<bool big_endian>
6507 void
6508 Arm_relobj<big_endian>::do_count_local_symbols(
6509     Stringpool_template<char>* pool,
6510     Stringpool_template<char>* dynpool)
6511 {
6512   // We need to fix-up the values of any local symbols whose type are
6513   // STT_ARM_TFUNC.
6514
6515   // Ask parent to count the local symbols.
6516   Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6517   const unsigned int loccount = this->local_symbol_count();
6518   if (loccount == 0)
6519     return;
6520
6521   // Initialize the thumb function bit-vector.
6522   std::vector<bool> empty_vector(loccount, false);
6523   this->local_symbol_is_thumb_function_.swap(empty_vector);
6524
6525   // Read the symbol table section header.
6526   const unsigned int symtab_shndx = this->symtab_shndx();
6527   elfcpp::Shdr<32, big_endian>
6528       symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6529   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6530
6531   // Read the local symbols.
6532   const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6533   gold_assert(loccount == symtabshdr.get_sh_info());
6534   off_t locsize = loccount * sym_size;
6535   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6536                                               locsize, true, true);
6537
6538   // For mapping symbol processing, we need to read the symbol names.
6539   unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6540   if (strtab_shndx >= this->shnum())
6541     {
6542       this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6543       return;
6544     }
6545
6546   elfcpp::Shdr<32, big_endian>
6547     strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6548   if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6549     {
6550       this->error(_("symbol table name section has wrong type: %u"),
6551                   static_cast<unsigned int>(strtabshdr.get_sh_type()));
6552       return;
6553     }
6554   const char* pnames =
6555     reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6556                                                  strtabshdr.get_sh_size(),
6557                                                  false, false));
6558
6559   // Loop over the local symbols and mark any local symbols pointing
6560   // to THUMB functions.
6561
6562   // Skip the first dummy symbol.
6563   psyms += sym_size;
6564   typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6565     this->local_values();
6566   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6567     {
6568       elfcpp::Sym<32, big_endian> sym(psyms);
6569       elfcpp::STT st_type = sym.get_st_type();
6570       Symbol_value<32>& lv((*plocal_values)[i]);
6571       Arm_address input_value = lv.input_value();
6572
6573       // Check to see if this is a mapping symbol.
6574       const char* sym_name = pnames + sym.get_st_name();
6575       if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6576         {
6577           bool is_ordinary;
6578           unsigned int input_shndx =
6579             this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6580           gold_assert(is_ordinary);
6581
6582           // Strip of LSB in case this is a THUMB symbol.
6583           Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6584           this->mapping_symbols_info_[msp] = sym_name[1];
6585         }
6586
6587       if (st_type == elfcpp::STT_ARM_TFUNC
6588           || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6589         {
6590           // This is a THUMB function.  Mark this and canonicalize the
6591           // symbol value by setting LSB.
6592           this->local_symbol_is_thumb_function_[i] = true;
6593           if ((input_value & 1) == 0)
6594             lv.set_input_value(input_value | 1);
6595         }
6596     }
6597 }
6598
6599 // Relocate sections.
6600 template<bool big_endian>
6601 void
6602 Arm_relobj<big_endian>::do_relocate_sections(
6603     const Symbol_table* symtab,
6604     const Layout* layout,
6605     const unsigned char* pshdrs,
6606     Output_file* of,
6607     typename Sized_relobj_file<32, big_endian>::Views* pviews)
6608 {
6609   // Relocate the section data.
6610   this->relocate_section_range(symtab, layout, pshdrs, of, pviews,
6611                                1, this->shnum() - 1);
6612
6613   // We do not generate stubs if doing a relocatable link.
6614   if (parameters->options().relocatable())
6615     return;
6616
6617   // Relocate stub tables.
6618   unsigned int shnum = this->shnum();
6619
6620   Target_arm<big_endian>* arm_target =
6621     Target_arm<big_endian>::default_target();
6622
6623   Relocate_info<32, big_endian> relinfo;
6624   relinfo.symtab = symtab;
6625   relinfo.layout = layout;
6626   relinfo.object = this;
6627
6628   for (unsigned int i = 1; i < shnum; ++i)
6629     {
6630       Arm_input_section<big_endian>* arm_input_section =
6631         arm_target->find_arm_input_section(this, i);
6632
6633       if (arm_input_section != NULL
6634           && arm_input_section->is_stub_table_owner()
6635           && !arm_input_section->stub_table()->empty())
6636         {
6637           // We cannot discard a section if it owns a stub table.
6638           Output_section* os = this->output_section(i);
6639           gold_assert(os != NULL);
6640
6641           relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6642           relinfo.reloc_shdr = NULL;
6643           relinfo.data_shndx = i;
6644           relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6645
6646           gold_assert((*pviews)[i].view != NULL);
6647
6648           // We are passed the output section view.  Adjust it to cover the
6649           // stub table only.
6650           Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6651           gold_assert((stub_table->address() >= (*pviews)[i].address)
6652                       && ((stub_table->address() + stub_table->data_size())
6653                           <= (*pviews)[i].address + (*pviews)[i].view_size));
6654
6655           off_t offset = stub_table->address() - (*pviews)[i].address;
6656           unsigned char* view = (*pviews)[i].view + offset;
6657           Arm_address address = stub_table->address();
6658           section_size_type view_size = stub_table->data_size();
6659
6660           stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6661                                      view_size);
6662         }
6663
6664       // Apply Cortex A8 workaround if applicable.
6665       if (this->section_has_cortex_a8_workaround(i))
6666         {
6667           unsigned char* view = (*pviews)[i].view;
6668           Arm_address view_address = (*pviews)[i].address;
6669           section_size_type view_size = (*pviews)[i].view_size;
6670           Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6671
6672           // Adjust view to cover section.
6673           Output_section* os = this->output_section(i);
6674           gold_assert(os != NULL);
6675           Arm_address section_address =
6676             this->simple_input_section_output_address(i, os);
6677           uint64_t section_size = this->section_size(i);
6678
6679           gold_assert(section_address >= view_address
6680                       && ((section_address + section_size)
6681                           <= (view_address + view_size)));
6682
6683           unsigned char* section_view = view + (section_address - view_address);
6684
6685           // Apply the Cortex-A8 workaround to the output address range
6686           // corresponding to this input section.
6687           stub_table->apply_cortex_a8_workaround_to_address_range(
6688               arm_target,
6689               section_view,
6690               section_address,
6691               section_size);
6692         }
6693         // BE8 swapping
6694         if (parameters->options().be8())
6695           {
6696             section_size_type  span_start, span_end;
6697             elfcpp::Shdr<32, big_endian>
6698               shdr(pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size);
6699             Mapping_symbol_position section_start(i, 0);
6700             typename Mapping_symbols_info::const_iterator p =
6701               this->mapping_symbols_info_.lower_bound(section_start);
6702             unsigned char* view = (*pviews)[i].view;
6703             Arm_address view_address = (*pviews)[i].address;
6704             section_size_type view_size = (*pviews)[i].view_size;
6705             while (p != this->mapping_symbols_info_.end()
6706                    && p->first.first == i)
6707               {
6708                 typename Mapping_symbols_info::const_iterator next =
6709                   this->mapping_symbols_info_.upper_bound(p->first);
6710
6711                 // Only swap arm or thumb code.
6712                 if ((p->second == 'a') || (p->second == 't'))
6713                   {
6714                     Output_section* os = this->output_section(i);
6715                     gold_assert(os != NULL);
6716                     Arm_address section_address =
6717                       this->simple_input_section_output_address(i, os);
6718                     span_start = convert_to_section_size_type(p->first.second);
6719                     if (next != this->mapping_symbols_info_.end()
6720                         && next->first.first == i)
6721                       span_end =
6722                         convert_to_section_size_type(next->first.second);
6723                     else
6724                       span_end =
6725                         convert_to_section_size_type(shdr.get_sh_size());
6726                     unsigned char* section_view =
6727                       view + (section_address - view_address);
6728                     uint64_t section_size = this->section_size(i);
6729
6730                     gold_assert(section_address >= view_address
6731                                 && ((section_address + section_size)
6732                                     <= (view_address + view_size)));
6733
6734                     // Set Output view for swapping
6735                     unsigned char *oview = section_view + span_start;
6736                     unsigned int index = 0;
6737                     if (p->second == 'a')
6738                       {
6739                         while (index + 3 < (span_end - span_start))
6740                           {
6741                             typedef typename elfcpp::Swap<32, big_endian>
6742                                                      ::Valtype Valtype;
6743                             Valtype* wv =
6744                               reinterpret_cast<Valtype*>(oview+index);
6745                             uint32_t val = elfcpp::Swap<32, false>::readval(wv);
6746                             elfcpp::Swap<32, true>::writeval(wv, val);
6747                             index += 4;
6748                           }
6749                       }
6750                     else if (p->second == 't')
6751                       {
6752                         while (index + 1 < (span_end - span_start))
6753                           {
6754                             typedef typename elfcpp::Swap<16, big_endian>
6755                                                      ::Valtype Valtype;
6756                             Valtype* wv =
6757                               reinterpret_cast<Valtype*>(oview+index);
6758                             uint16_t val = elfcpp::Swap<16, false>::readval(wv);
6759                             elfcpp::Swap<16, true>::writeval(wv, val);
6760                             index += 2;
6761                            }
6762                       }
6763                   }
6764                 p = next;
6765               }
6766           }
6767     }
6768 }
6769
6770 // Find the linked text section of an EXIDX section by looking at the first
6771 // relocation.  4.4.1 of the EHABI specifications says that an EXIDX section
6772 // must be linked to its associated code section via the sh_link field of
6773 // its section header.  However, some tools are broken and the link is not
6774 // always set.  LD just drops such an EXIDX section silently, causing the
6775 // associated code not unwindabled.   Here we try a little bit harder to
6776 // discover the linked code section.
6777 //
6778 // PSHDR points to the section header of a relocation section of an EXIDX
6779 // section.  If we can find a linked text section, return true and
6780 // store the text section index in the location PSHNDX.  Otherwise
6781 // return false.
6782
6783 template<bool big_endian>
6784 bool
6785 Arm_relobj<big_endian>::find_linked_text_section(
6786     const unsigned char* pshdr,
6787     const unsigned char* psyms,
6788     unsigned int* pshndx)
6789 {
6790   elfcpp::Shdr<32, big_endian> shdr(pshdr);
6791
6792   // If there is no relocation, we cannot find the linked text section.
6793   size_t reloc_size;
6794   if (shdr.get_sh_type() == elfcpp::SHT_REL)
6795       reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6796   else
6797       reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6798   size_t reloc_count = shdr.get_sh_size() / reloc_size;
6799
6800   // Get the relocations.
6801   const unsigned char* prelocs =
6802       this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6803
6804   // Find the REL31 relocation for the first word of the first EXIDX entry.
6805   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6806     {
6807       Arm_address r_offset;
6808       typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6809       if (shdr.get_sh_type() == elfcpp::SHT_REL)
6810         {
6811           typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6812           r_info = reloc.get_r_info();
6813           r_offset = reloc.get_r_offset();
6814         }
6815       else
6816         {
6817           typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6818           r_info = reloc.get_r_info();
6819           r_offset = reloc.get_r_offset();
6820         }
6821
6822       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6823       if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6824         continue;
6825
6826       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6827       if (r_sym == 0
6828           || r_sym >= this->local_symbol_count()
6829           || r_offset != 0)
6830         continue;
6831
6832       // This is the relocation for the first word of the first EXIDX entry.
6833       // We expect to see a local section symbol.
6834       const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6835       elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6836       if (sym.get_st_type() == elfcpp::STT_SECTION)
6837         {
6838           bool is_ordinary;
6839           *pshndx =
6840             this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6841           gold_assert(is_ordinary);
6842           return true;
6843         }
6844       else
6845         return false;
6846     }
6847
6848   return false;
6849 }
6850
6851 // Make an EXIDX input section object for an EXIDX section whose index is
6852 // SHNDX.  SHDR is the section header of the EXIDX section and TEXT_SHNDX
6853 // is the section index of the linked text section.
6854
6855 template<bool big_endian>
6856 void
6857 Arm_relobj<big_endian>::make_exidx_input_section(
6858     unsigned int shndx,
6859     const elfcpp::Shdr<32, big_endian>& shdr,
6860     unsigned int text_shndx,
6861     const elfcpp::Shdr<32, big_endian>& text_shdr)
6862 {
6863   // Create an Arm_exidx_input_section object for this EXIDX section.
6864   Arm_exidx_input_section* exidx_input_section =
6865     new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6866                                 shdr.get_sh_addralign(),
6867                                 text_shdr.get_sh_size());
6868
6869   gold_assert(this->exidx_section_map_[shndx] == NULL);
6870   this->exidx_section_map_[shndx] = exidx_input_section;
6871
6872   if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6873     {
6874       gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6875                  this->section_name(shndx).c_str(), shndx, text_shndx,
6876                  this->name().c_str());
6877       exidx_input_section->set_has_errors();
6878     }
6879   else if (this->exidx_section_map_[text_shndx] != NULL)
6880     {
6881       unsigned other_exidx_shndx =
6882         this->exidx_section_map_[text_shndx]->shndx();
6883       gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6884                    "%s(%u) in %s"),
6885                  this->section_name(shndx).c_str(), shndx,
6886                  this->section_name(other_exidx_shndx).c_str(),
6887                  other_exidx_shndx, this->section_name(text_shndx).c_str(),
6888                  text_shndx, this->name().c_str());
6889       exidx_input_section->set_has_errors();
6890     }
6891   else
6892      this->exidx_section_map_[text_shndx] = exidx_input_section;
6893
6894   // Check section flags of text section.
6895   if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6896     {
6897       gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6898                    " in %s"),
6899                  this->section_name(shndx).c_str(), shndx,
6900                  this->section_name(text_shndx).c_str(), text_shndx,
6901                  this->name().c_str());
6902       exidx_input_section->set_has_errors();
6903     }
6904   else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6905     // I would like to make this an error but currently ld just ignores
6906     // this.
6907     gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6908                    "%s(%u) in %s"),
6909                  this->section_name(shndx).c_str(), shndx,
6910                  this->section_name(text_shndx).c_str(), text_shndx,
6911                  this->name().c_str());
6912 }
6913
6914 // Read the symbol information.
6915
6916 template<bool big_endian>
6917 void
6918 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6919 {
6920   // Call parent class to read symbol information.
6921   this->base_read_symbols(sd);
6922
6923   // If this input file is a binary file, it has no processor
6924   // specific flags and attributes section.
6925   Input_file::Format format = this->input_file()->format();
6926   if (format != Input_file::FORMAT_ELF)
6927     {
6928       gold_assert(format == Input_file::FORMAT_BINARY);
6929       this->merge_flags_and_attributes_ = false;
6930       return;
6931     }
6932
6933   // Read processor-specific flags in ELF file header.
6934   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6935                                               elfcpp::Elf_sizes<32>::ehdr_size,
6936                                               true, false);
6937   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6938   this->processor_specific_flags_ = ehdr.get_e_flags();
6939
6940   // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6941   // sections.
6942   std::vector<unsigned int> deferred_exidx_sections;
6943   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6944   const unsigned char* pshdrs = sd->section_headers->data();
6945   const unsigned char* ps = pshdrs + shdr_size;
6946   bool must_merge_flags_and_attributes = false;
6947   for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6948     {
6949       elfcpp::Shdr<32, big_endian> shdr(ps);
6950
6951       // Sometimes an object has no contents except the section name string
6952       // table and an empty symbol table with the undefined symbol.  We
6953       // don't want to merge processor-specific flags from such an object.
6954       if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6955         {
6956           // Symbol table is not empty.
6957           const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6958              elfcpp::Elf_sizes<32>::sym_size;
6959           if (shdr.get_sh_size() > sym_size)
6960             must_merge_flags_and_attributes = true;
6961         }
6962       else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6963         // If this is neither an empty symbol table nor a string table,
6964         // be conservative.
6965         must_merge_flags_and_attributes = true;
6966
6967       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6968         {
6969           gold_assert(this->attributes_section_data_ == NULL);
6970           section_offset_type section_offset = shdr.get_sh_offset();
6971           section_size_type section_size =
6972             convert_to_section_size_type(shdr.get_sh_size());
6973           const unsigned char* view =
6974              this->get_view(section_offset, section_size, true, false);
6975           this->attributes_section_data_ =
6976             new Attributes_section_data(view, section_size);
6977         }
6978       else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6979         {
6980           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6981           if (text_shndx == elfcpp::SHN_UNDEF)
6982             deferred_exidx_sections.push_back(i);
6983           else
6984             {
6985               elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6986                                                      + text_shndx * shdr_size);
6987               this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6988             }
6989           // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6990           if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6991             gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6992                          this->section_name(i).c_str(), this->name().c_str());
6993         }
6994     }
6995
6996   // This is rare.
6997   if (!must_merge_flags_and_attributes)
6998     {
6999       gold_assert(deferred_exidx_sections.empty());
7000       this->merge_flags_and_attributes_ = false;
7001       return;
7002     }
7003
7004   // Some tools are broken and they do not set the link of EXIDX sections.
7005   // We look at the first relocation to figure out the linked sections.
7006   if (!deferred_exidx_sections.empty())
7007     {
7008       // We need to go over the section headers again to find the mapping
7009       // from sections being relocated to their relocation sections.  This is
7010       // a bit inefficient as we could do that in the loop above.  However,
7011       // we do not expect any deferred EXIDX sections normally.  So we do not
7012       // want to slow down the most common path.
7013       typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
7014       Reloc_map reloc_map;
7015       ps = pshdrs + shdr_size;
7016       for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
7017         {
7018           elfcpp::Shdr<32, big_endian> shdr(ps);
7019           elfcpp::Elf_Word sh_type = shdr.get_sh_type();
7020           if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
7021             {
7022               unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
7023               if (info_shndx >= this->shnum())
7024                 gold_error(_("relocation section %u has invalid info %u"),
7025                            i, info_shndx);
7026               Reloc_map::value_type value(info_shndx, i);
7027               std::pair<Reloc_map::iterator, bool> result =
7028                 reloc_map.insert(value);
7029               if (!result.second)
7030                 gold_error(_("section %u has multiple relocation sections "
7031                              "%u and %u"),
7032                            info_shndx, i, reloc_map[info_shndx]);
7033             }
7034         }
7035
7036       // Read the symbol table section header.
7037       const unsigned int symtab_shndx = this->symtab_shndx();
7038       elfcpp::Shdr<32, big_endian>
7039           symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
7040       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
7041
7042       // Read the local symbols.
7043       const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
7044       const unsigned int loccount = this->local_symbol_count();
7045       gold_assert(loccount == symtabshdr.get_sh_info());
7046       off_t locsize = loccount * sym_size;
7047       const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
7048                                                   locsize, true, true);
7049
7050       // Process the deferred EXIDX sections.
7051       for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
7052         {
7053           unsigned int shndx = deferred_exidx_sections[i];
7054           elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
7055           unsigned int text_shndx = elfcpp::SHN_UNDEF;
7056           Reloc_map::const_iterator it = reloc_map.find(shndx);
7057           if (it != reloc_map.end())
7058             find_linked_text_section(pshdrs + it->second * shdr_size,
7059                                      psyms, &text_shndx);
7060           elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
7061                                                  + text_shndx * shdr_size);
7062           this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
7063         }
7064     }
7065 }
7066
7067 // Process relocations for garbage collection.  The ARM target uses .ARM.exidx
7068 // sections for unwinding.  These sections are referenced implicitly by
7069 // text sections linked in the section headers.  If we ignore these implicit
7070 // references, the .ARM.exidx sections and any .ARM.extab sections they use
7071 // will be garbage-collected incorrectly.  Hence we override the same function
7072 // in the base class to handle these implicit references.
7073
7074 template<bool big_endian>
7075 void
7076 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
7077                                              Layout* layout,
7078                                              Read_relocs_data* rd)
7079 {
7080   // First, call base class method to process relocations in this object.
7081   Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
7082
7083   // If --gc-sections is not specified, there is nothing more to do.
7084   // This happens when --icf is used but --gc-sections is not.
7085   if (!parameters->options().gc_sections())
7086     return;
7087
7088   unsigned int shnum = this->shnum();
7089   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
7090   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
7091                                                shnum * shdr_size,
7092                                                true, true);
7093
7094   // Scan section headers for sections of type SHT_ARM_EXIDX.  Add references
7095   // to these from the linked text sections.
7096   const unsigned char* ps = pshdrs + shdr_size;
7097   for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
7098     {
7099       elfcpp::Shdr<32, big_endian> shdr(ps);
7100       if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
7101         {
7102           // Found an .ARM.exidx section, add it to the set of reachable
7103           // sections from its linked text section.
7104           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
7105           symtab->gc()->add_reference(this, text_shndx, this, i);
7106         }
7107     }
7108 }
7109
7110 // Update output local symbol count.  Owing to EXIDX entry merging, some local
7111 // symbols  will be removed in output.  Adjust output local symbol count
7112 // accordingly.  We can only changed the static output local symbol count.  It
7113 // is too late to change the dynamic symbols.
7114
7115 template<bool big_endian>
7116 void
7117 Arm_relobj<big_endian>::update_output_local_symbol_count()
7118 {
7119   // Caller should check that this needs updating.  We want caller checking
7120   // because output_local_symbol_count_needs_update() is most likely inlined.
7121   gold_assert(this->output_local_symbol_count_needs_update_);
7122
7123   gold_assert(this->symtab_shndx() != -1U);
7124   if (this->symtab_shndx() == 0)
7125     {
7126       // This object has no symbols.  Weird but legal.
7127       return;
7128     }
7129
7130   // Read the symbol table section header.
7131   const unsigned int symtab_shndx = this->symtab_shndx();
7132   elfcpp::Shdr<32, big_endian>
7133     symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
7134   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
7135
7136   // Read the local symbols.
7137   const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
7138   const unsigned int loccount = this->local_symbol_count();
7139   gold_assert(loccount == symtabshdr.get_sh_info());
7140   off_t locsize = loccount * sym_size;
7141   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
7142                                               locsize, true, true);
7143
7144   // Loop over the local symbols.
7145
7146   typedef typename Sized_relobj_file<32, big_endian>::Output_sections
7147      Output_sections;
7148   const Output_sections& out_sections(this->output_sections());
7149   unsigned int shnum = this->shnum();
7150   unsigned int count = 0;
7151   // Skip the first, dummy, symbol.
7152   psyms += sym_size;
7153   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
7154     {
7155       elfcpp::Sym<32, big_endian> sym(psyms);
7156
7157       Symbol_value<32>& lv((*this->local_values())[i]);
7158
7159       // This local symbol was already discarded by do_count_local_symbols.
7160       if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
7161         continue;
7162
7163       bool is_ordinary;
7164       unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
7165                                                   &is_ordinary);
7166
7167       if (shndx < shnum)
7168         {
7169           Output_section* os = out_sections[shndx];
7170
7171           // This local symbol no longer has an output section.  Discard it.
7172           if (os == NULL)
7173             {
7174               lv.set_no_output_symtab_entry();
7175               continue;
7176             }
7177
7178           // Currently we only discard parts of EXIDX input sections.
7179           // We explicitly check for a merged EXIDX input section to avoid
7180           // calling Output_section_data::output_offset unless necessary.
7181           if ((this->get_output_section_offset(shndx) == invalid_address)
7182               && (this->exidx_input_section_by_shndx(shndx) != NULL))
7183             {
7184               section_offset_type output_offset =
7185                 os->output_offset(this, shndx, lv.input_value());
7186               if (output_offset == -1)
7187                 {
7188                   // This symbol is defined in a part of an EXIDX input section
7189                   // that is discarded due to entry merging.
7190                   lv.set_no_output_symtab_entry();
7191                   continue;
7192                 }
7193             }
7194         }
7195
7196       ++count;
7197     }
7198
7199   this->set_output_local_symbol_count(count);
7200   this->output_local_symbol_count_needs_update_ = false;
7201 }
7202
7203 // Arm_dynobj methods.
7204
7205 // Read the symbol information.
7206
7207 template<bool big_endian>
7208 void
7209 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
7210 {
7211   // Call parent class to read symbol information.
7212   this->base_read_symbols(sd);
7213
7214   // Read processor-specific flags in ELF file header.
7215   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
7216                                               elfcpp::Elf_sizes<32>::ehdr_size,
7217                                               true, false);
7218   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
7219   this->processor_specific_flags_ = ehdr.get_e_flags();
7220
7221   // Read the attributes section if there is one.
7222   // We read from the end because gas seems to put it near the end of
7223   // the section headers.
7224   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
7225   const unsigned char* ps =
7226     sd->section_headers->data() + shdr_size * (this->shnum() - 1);
7227   for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
7228     {
7229       elfcpp::Shdr<32, big_endian> shdr(ps);
7230       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
7231         {
7232           section_offset_type section_offset = shdr.get_sh_offset();
7233           section_size_type section_size =
7234             convert_to_section_size_type(shdr.get_sh_size());
7235           const unsigned char* view =
7236             this->get_view(section_offset, section_size, true, false);
7237           this->attributes_section_data_ =
7238             new Attributes_section_data(view, section_size);
7239           break;
7240         }
7241     }
7242 }
7243
7244 // Stub_addend_reader methods.
7245
7246 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7247
7248 template<bool big_endian>
7249 elfcpp::Elf_types<32>::Elf_Swxword
7250 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7251     unsigned int r_type,
7252     const unsigned char* view,
7253     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7254 {
7255   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
7256
7257   switch (r_type)
7258     {
7259     case elfcpp::R_ARM_CALL:
7260     case elfcpp::R_ARM_JUMP24:
7261     case elfcpp::R_ARM_PLT32:
7262       {
7263         typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7264         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7265         Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7266         return Bits<26>::sign_extend32(val << 2);
7267       }
7268
7269     case elfcpp::R_ARM_THM_CALL:
7270     case elfcpp::R_ARM_THM_JUMP24:
7271     case elfcpp::R_ARM_THM_XPC22:
7272       {
7273         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7274         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7275         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7276         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7277         return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7278       }
7279
7280     case elfcpp::R_ARM_THM_JUMP19:
7281       {
7282         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7283         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7284         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7285         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7286         return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7287       }
7288
7289     default:
7290       gold_unreachable();
7291     }
7292 }
7293
7294 // Arm_output_data_got methods.
7295
7296 // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
7297 // The first one is initialized to be 1, which is the module index for
7298 // the main executable and the second one 0.  A reloc of the type
7299 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7300 // be applied by gold.  GSYM is a global symbol.
7301 //
7302 template<bool big_endian>
7303 void
7304 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7305     unsigned int got_type,
7306     Symbol* gsym)
7307 {
7308   if (gsym->has_got_offset(got_type))
7309     return;
7310
7311   // We are doing a static link.  Just mark it as belong to module 1,
7312   // the executable.
7313   unsigned int got_offset = this->add_constant(1);
7314   gsym->set_got_offset(got_type, got_offset);
7315   got_offset = this->add_constant(0);
7316   this->static_relocs_.push_back(Static_reloc(got_offset,
7317                                               elfcpp::R_ARM_TLS_DTPOFF32,
7318                                               gsym));
7319 }
7320
7321 // Same as the above but for a local symbol.
7322
7323 template<bool big_endian>
7324 void
7325 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7326   unsigned int got_type,
7327   Sized_relobj_file<32, big_endian>* object,
7328   unsigned int index)
7329 {
7330   if (object->local_has_got_offset(index, got_type))
7331     return;
7332
7333   // We are doing a static link.  Just mark it as belong to module 1,
7334   // the executable.
7335   unsigned int got_offset = this->add_constant(1);
7336   object->set_local_got_offset(index, got_type, got_offset);
7337   got_offset = this->add_constant(0);
7338   this->static_relocs_.push_back(Static_reloc(got_offset,
7339                                               elfcpp::R_ARM_TLS_DTPOFF32,
7340                                               object, index));
7341 }
7342
7343 template<bool big_endian>
7344 void
7345 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7346 {
7347   // Call parent to write out GOT.
7348   Output_data_got<32, big_endian>::do_write(of);
7349
7350   // We are done if there is no fix up.
7351   if (this->static_relocs_.empty())
7352     return;
7353
7354   gold_assert(parameters->doing_static_link());
7355
7356   const off_t offset = this->offset();
7357   const section_size_type oview_size =
7358     convert_to_section_size_type(this->data_size());
7359   unsigned char* const oview = of->get_output_view(offset, oview_size);
7360
7361   Output_segment* tls_segment = this->layout_->tls_segment();
7362   gold_assert(tls_segment != NULL);
7363
7364   // The thread pointer $tp points to the TCB, which is followed by the
7365   // TLS.  So we need to adjust $tp relative addressing by this amount.
7366   Arm_address aligned_tcb_size =
7367     align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7368
7369   for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7370     {
7371       Static_reloc& reloc(this->static_relocs_[i]);
7372
7373       Arm_address value;
7374       if (!reloc.symbol_is_global())
7375         {
7376           Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7377           const Symbol_value<32>* psymval =
7378             reloc.relobj()->local_symbol(reloc.index());
7379
7380           // We are doing static linking.  Issue an error and skip this
7381           // relocation if the symbol is undefined or in a discarded_section.
7382           bool is_ordinary;
7383           unsigned int shndx = psymval->input_shndx(&is_ordinary);
7384           if ((shndx == elfcpp::SHN_UNDEF)
7385               || (is_ordinary
7386                   && shndx != elfcpp::SHN_UNDEF
7387                   && !object->is_section_included(shndx)
7388                   && !this->symbol_table_->is_section_folded(object, shndx)))
7389             {
7390               gold_error(_("undefined or discarded local symbol %u from "
7391                            " object %s in GOT"),
7392                          reloc.index(), reloc.relobj()->name().c_str());
7393               continue;
7394             }
7395
7396           value = psymval->value(object, 0);
7397         }
7398       else
7399         {
7400           const Symbol* gsym = reloc.symbol();
7401           gold_assert(gsym != NULL);
7402           if (gsym->is_forwarder())
7403             gsym = this->symbol_table_->resolve_forwards(gsym);
7404
7405           // We are doing static linking.  Issue an error and skip this
7406           // relocation if the symbol is undefined or in a discarded_section
7407           // unless it is a weakly_undefined symbol.
7408           if ((gsym->is_defined_in_discarded_section()
7409                || gsym->is_undefined())
7410               && !gsym->is_weak_undefined())
7411             {
7412               gold_error(_("undefined or discarded symbol %s in GOT"),
7413                          gsym->name());
7414               continue;
7415             }
7416
7417           if (!gsym->is_weak_undefined())
7418             {
7419               const Sized_symbol<32>* sym =
7420                 static_cast<const Sized_symbol<32>*>(gsym);
7421               value = sym->value();
7422             }
7423           else
7424               value = 0;
7425         }
7426
7427       unsigned got_offset = reloc.got_offset();
7428       gold_assert(got_offset < oview_size);
7429
7430       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7431       Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7432       Valtype x;
7433       switch (reloc.r_type())
7434         {
7435         case elfcpp::R_ARM_TLS_DTPOFF32:
7436           x = value;
7437           break;
7438         case elfcpp::R_ARM_TLS_TPOFF32:
7439           x = value + aligned_tcb_size;
7440           break;
7441         default:
7442           gold_unreachable();
7443         }
7444       elfcpp::Swap<32, big_endian>::writeval(wv, x);
7445     }
7446
7447   of->write_output_view(offset, oview_size, oview);
7448 }
7449
7450 // A class to handle the PLT data.
7451 // This is an abstract base class that handles most of the linker details
7452 // but does not know the actual contents of PLT entries.  The derived
7453 // classes below fill in those details.
7454
7455 template<bool big_endian>
7456 class Output_data_plt_arm : public Output_section_data
7457 {
7458  public:
7459   // Unlike aarch64, which records symbol value in "addend" field of relocations
7460   // and could be done at the same time an IRelative reloc is created for the
7461   // symbol, arm puts the symbol value into "GOT" table, which, however, is
7462   // issued later in Output_data_plt_arm::do_write(). So we have a struct here
7463   // to keep necessary symbol information for later use in do_write. We usually
7464   // have only a very limited number of ifuncs, so the extra data required here
7465   // is also limited.
7466
7467   struct IRelative_data
7468   {
7469     IRelative_data(Sized_symbol<32>* sized_symbol)
7470       : symbol_is_global_(true)
7471     {
7472       u_.global = sized_symbol;
7473     }
7474
7475     IRelative_data(Sized_relobj_file<32, big_endian>* relobj,
7476                    unsigned int index)
7477       : symbol_is_global_(false)
7478     {
7479       u_.local.relobj = relobj;
7480       u_.local.index = index;
7481     }
7482
7483     union
7484     {
7485       Sized_symbol<32>* global;
7486
7487       struct
7488       {
7489         Sized_relobj_file<32, big_endian>* relobj;
7490         unsigned int index;
7491       } local;
7492     } u_;
7493
7494     bool symbol_is_global_;
7495   };
7496
7497   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7498     Reloc_section;
7499
7500   Output_data_plt_arm(Layout* layout, uint64_t addralign,
7501                       Arm_output_data_got<big_endian>* got,
7502                       Output_data_space* got_plt,
7503                       Output_data_space* got_irelative);
7504
7505   // Add an entry to the PLT.
7506   void
7507   add_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym);
7508
7509   // Add the relocation for a plt entry.
7510   void
7511   add_relocation(Symbol_table* symtab, Layout* layout,
7512                  Symbol* gsym, unsigned int got_offset);
7513
7514   // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
7515   unsigned int
7516   add_local_ifunc_entry(Symbol_table* symtab, Layout*,
7517                         Sized_relobj_file<32, big_endian>* relobj,
7518                         unsigned int local_sym_index);
7519
7520   // Return the .rel.plt section data.
7521   const Reloc_section*
7522   rel_plt() const
7523   { return this->rel_; }
7524
7525   // Return the PLT relocation container for IRELATIVE.
7526   Reloc_section*
7527   rel_irelative(Symbol_table*, Layout*);
7528
7529   // Return the number of PLT entries.
7530   unsigned int
7531   entry_count() const
7532   { return this->count_ + this->irelative_count_; }
7533
7534   // Return the offset of the first non-reserved PLT entry.
7535   unsigned int
7536   first_plt_entry_offset() const
7537   { return this->do_first_plt_entry_offset(); }
7538
7539   // Return the size of a PLT entry.
7540   unsigned int
7541   get_plt_entry_size() const
7542   { return this->do_get_plt_entry_size(); }
7543
7544   // Return the PLT address for globals.
7545   uint32_t
7546   address_for_global(const Symbol*) const;
7547
7548   // Return the PLT address for locals.
7549   uint32_t
7550   address_for_local(const Relobj*, unsigned int symndx) const;
7551
7552  protected:
7553   // Fill in the first PLT entry.
7554   void
7555   fill_first_plt_entry(unsigned char* pov,
7556                        Arm_address got_address,
7557                        Arm_address plt_address)
7558   { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
7559
7560   void
7561   fill_plt_entry(unsigned char* pov,
7562                  Arm_address got_address,
7563                  Arm_address plt_address,
7564                  unsigned int got_offset,
7565                  unsigned int plt_offset)
7566   { do_fill_plt_entry(pov, got_address, plt_address, got_offset, plt_offset); }
7567
7568   virtual unsigned int
7569   do_first_plt_entry_offset() const = 0;
7570
7571   virtual unsigned int
7572   do_get_plt_entry_size() const = 0;
7573
7574   virtual void
7575   do_fill_first_plt_entry(unsigned char* pov,
7576                           Arm_address got_address,
7577                           Arm_address plt_address) = 0;
7578
7579   virtual void
7580   do_fill_plt_entry(unsigned char* pov,
7581                     Arm_address got_address,
7582                     Arm_address plt_address,
7583                     unsigned int got_offset,
7584                     unsigned int plt_offset) = 0;
7585
7586   void
7587   do_adjust_output_section(Output_section* os);
7588
7589   // Write to a map file.
7590   void
7591   do_print_to_mapfile(Mapfile* mapfile) const
7592   { mapfile->print_output_data(this, _("** PLT")); }
7593
7594  private:
7595   // Set the final size.
7596   void
7597   set_final_data_size()
7598   {
7599     this->set_data_size(this->first_plt_entry_offset()
7600                         + ((this->count_ + this->irelative_count_)
7601                            * this->get_plt_entry_size()));
7602   }
7603
7604   // Write out the PLT data.
7605   void
7606   do_write(Output_file*);
7607
7608   // Record irelative symbol data.
7609   void insert_irelative_data(const IRelative_data& idata)
7610   { irelative_data_vec_.push_back(idata); }
7611
7612   // The reloc section.
7613   Reloc_section* rel_;
7614   // The IRELATIVE relocs, if necessary.  These must follow the
7615   // regular PLT relocations.
7616   Reloc_section* irelative_rel_;
7617   // The .got section.
7618   Arm_output_data_got<big_endian>* got_;
7619   // The .got.plt section.
7620   Output_data_space* got_plt_;
7621   // The part of the .got.plt section used for IRELATIVE relocs.
7622   Output_data_space* got_irelative_;
7623   // The number of PLT entries.
7624   unsigned int count_;
7625   // Number of PLT entries with R_ARM_IRELATIVE relocs.  These
7626   // follow the regular PLT entries.
7627   unsigned int irelative_count_;
7628   // Vector for irelative data.
7629   typedef std::vector<IRelative_data> IRelative_data_vec;
7630   IRelative_data_vec irelative_data_vec_;
7631 };
7632
7633 // Create the PLT section.  The ordinary .got section is an argument,
7634 // since we need to refer to the start.  We also create our own .got
7635 // section just for PLT entries.
7636
7637 template<bool big_endian>
7638 Output_data_plt_arm<big_endian>::Output_data_plt_arm(
7639     Layout* layout, uint64_t addralign,
7640     Arm_output_data_got<big_endian>* got,
7641     Output_data_space* got_plt,
7642     Output_data_space* got_irelative)
7643   : Output_section_data(addralign), irelative_rel_(NULL),
7644     got_(got), got_plt_(got_plt), got_irelative_(got_irelative),
7645     count_(0), irelative_count_(0)
7646 {
7647   this->rel_ = new Reloc_section(false);
7648   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7649                                   elfcpp::SHF_ALLOC, this->rel_,
7650                                   ORDER_DYNAMIC_PLT_RELOCS, false);
7651 }
7652
7653 template<bool big_endian>
7654 void
7655 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7656 {
7657   os->set_entsize(0);
7658 }
7659
7660 // Add an entry to the PLT.
7661
7662 template<bool big_endian>
7663 void
7664 Output_data_plt_arm<big_endian>::add_entry(Symbol_table* symtab,
7665                                            Layout* layout,
7666                                            Symbol* gsym)
7667 {
7668   gold_assert(!gsym->has_plt_offset());
7669
7670   unsigned int* entry_count;
7671   Output_section_data_build* got;
7672
7673   // We have 2 different types of plt entry here, normal and ifunc.
7674
7675   // For normal plt, the offset begins with first_plt_entry_offset(20), and the
7676   // 1st entry offset would be 20, the second 32, third 44 ... etc.
7677
7678   // For ifunc plt, the offset begins with 0. So the first offset would 0,
7679   // second 12, third 24 ... etc.
7680
7681   // IFunc plt entries *always* come after *normal* plt entries.
7682
7683   // Notice, when computing the plt address of a certain symbol, "plt_address +
7684   // plt_offset" is no longer correct. Use target->plt_address_for_global() or
7685   // target->plt_address_for_local() instead.
7686
7687   int begin_offset = 0;
7688   if (gsym->type() == elfcpp::STT_GNU_IFUNC
7689       && gsym->can_use_relative_reloc(false))
7690     {
7691       entry_count = &this->irelative_count_;
7692       got = this->got_irelative_;
7693       // For irelative plt entries, offset is relative to the end of normal plt
7694       // entries, so it starts from 0.
7695       begin_offset = 0;
7696       // Record symbol information.
7697       this->insert_irelative_data(
7698           IRelative_data(symtab->get_sized_symbol<32>(gsym)));
7699     }
7700   else
7701     {
7702       entry_count = &this->count_;
7703       got = this->got_plt_;
7704       // Note that for normal plt entries, when setting the PLT offset we skip
7705       // the initial reserved PLT entry.
7706       begin_offset = this->first_plt_entry_offset();
7707     }
7708
7709   gsym->set_plt_offset(begin_offset
7710                        + (*entry_count) * this->get_plt_entry_size());
7711
7712   ++(*entry_count);
7713
7714   section_offset_type got_offset = got->current_data_size();
7715
7716   // Every PLT entry needs a GOT entry which points back to the PLT
7717   // entry (this will be changed by the dynamic linker, normally
7718   // lazily when the function is called).
7719   got->set_current_data_size(got_offset + 4);
7720
7721   // Every PLT entry needs a reloc.
7722   this->add_relocation(symtab, layout, gsym, got_offset);
7723
7724   // Note that we don't need to save the symbol.  The contents of the
7725   // PLT are independent of which symbols are used.  The symbols only
7726   // appear in the relocations.
7727 }
7728
7729 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.  Return
7730 // the PLT offset.
7731
7732 template<bool big_endian>
7733 unsigned int
7734 Output_data_plt_arm<big_endian>::add_local_ifunc_entry(
7735     Symbol_table* symtab,
7736     Layout* layout,
7737     Sized_relobj_file<32, big_endian>* relobj,
7738     unsigned int local_sym_index)
7739 {
7740   this->insert_irelative_data(IRelative_data(relobj, local_sym_index));
7741
7742   // Notice, when computingthe plt entry address, "plt_address + plt_offset" is
7743   // no longer correct. Use target->plt_address_for_local() instead.
7744   unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
7745   ++this->irelative_count_;
7746
7747   section_offset_type got_offset = this->got_irelative_->current_data_size();
7748
7749   // Every PLT entry needs a GOT entry which points back to the PLT
7750   // entry.
7751   this->got_irelative_->set_current_data_size(got_offset + 4);
7752
7753
7754   // Every PLT entry needs a reloc.
7755   Reloc_section* rel = this->rel_irelative(symtab, layout);
7756   rel->add_symbolless_local_addend(relobj, local_sym_index,
7757                                    elfcpp::R_ARM_IRELATIVE,
7758                                    this->got_irelative_, got_offset);
7759   return plt_offset;
7760 }
7761
7762
7763 // Add the relocation for a PLT entry.
7764
7765 template<bool big_endian>
7766 void
7767 Output_data_plt_arm<big_endian>::add_relocation(
7768     Symbol_table* symtab, Layout* layout, Symbol* gsym, unsigned int got_offset)
7769 {
7770   if (gsym->type() == elfcpp::STT_GNU_IFUNC
7771       && gsym->can_use_relative_reloc(false))
7772     {
7773       Reloc_section* rel = this->rel_irelative(symtab, layout);
7774       rel->add_symbolless_global_addend(gsym, elfcpp::R_ARM_IRELATIVE,
7775                                         this->got_irelative_, got_offset);
7776     }
7777   else
7778     {
7779       gsym->set_needs_dynsym_entry();
7780       this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7781                              got_offset);
7782     }
7783 }
7784
7785
7786 // Create the irelative relocation data.
7787
7788 template<bool big_endian>
7789 typename Output_data_plt_arm<big_endian>::Reloc_section*
7790 Output_data_plt_arm<big_endian>::rel_irelative(Symbol_table* symtab,
7791                                                 Layout* layout)
7792 {
7793   if (this->irelative_rel_ == NULL)
7794     {
7795       // Since irelative relocations goes into 'rel.dyn', we delegate the
7796       // creation of irelative_rel_ to where rel_dyn section gets created.
7797       Target_arm<big_endian>* arm_target =
7798           Target_arm<big_endian>::default_target();
7799       this->irelative_rel_ = arm_target->rel_irelative_section(layout);
7800
7801       // Make sure we have a place for the TLSDESC relocations, in
7802       // case we see any later on.
7803       // this->rel_tlsdesc(layout);
7804       if (parameters->doing_static_link())
7805         {
7806           // A statically linked executable will only have a .rel.plt section to
7807           // hold R_ARM_IRELATIVE relocs for STT_GNU_IFUNC symbols.  The library
7808           // will use these symbols to locate the IRELATIVE relocs at program
7809           // startup time.
7810           symtab->define_in_output_data("__rel_iplt_start", NULL,
7811                                         Symbol_table::PREDEFINED,
7812                                         this->irelative_rel_, 0, 0,
7813                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
7814                                         elfcpp::STV_HIDDEN, 0, false, true);
7815           symtab->define_in_output_data("__rel_iplt_end", NULL,
7816                                         Symbol_table::PREDEFINED,
7817                                         this->irelative_rel_, 0, 0,
7818                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
7819                                         elfcpp::STV_HIDDEN, 0, true, true);
7820         }
7821     }
7822   return this->irelative_rel_;
7823 }
7824
7825
7826 // Return the PLT address for a global symbol.
7827
7828 template<bool big_endian>
7829 uint32_t
7830 Output_data_plt_arm<big_endian>::address_for_global(const Symbol* gsym) const
7831 {
7832   uint64_t begin_offset = 0;
7833   if (gsym->type() == elfcpp::STT_GNU_IFUNC
7834       && gsym->can_use_relative_reloc(false))
7835     {
7836       begin_offset = (this->first_plt_entry_offset() +
7837                       this->count_ * this->get_plt_entry_size());
7838     }
7839   return this->address() + begin_offset + gsym->plt_offset();
7840 }
7841
7842
7843 // Return the PLT address for a local symbol.  These are always
7844 // IRELATIVE relocs.
7845
7846 template<bool big_endian>
7847 uint32_t
7848 Output_data_plt_arm<big_endian>::address_for_local(
7849     const Relobj* object,
7850     unsigned int r_sym) const
7851 {
7852   return (this->address()
7853           + this->first_plt_entry_offset()
7854           + this->count_ * this->get_plt_entry_size()
7855           + object->local_plt_offset(r_sym));
7856 }
7857
7858
7859 template<bool big_endian>
7860 class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
7861 {
7862  public:
7863   Output_data_plt_arm_standard(Layout* layout,
7864                                Arm_output_data_got<big_endian>* got,
7865                                Output_data_space* got_plt,
7866                                Output_data_space* got_irelative)
7867     : Output_data_plt_arm<big_endian>(layout, 4, got, got_plt, got_irelative)
7868   { }
7869
7870  protected:
7871   // Return the offset of the first non-reserved PLT entry.
7872   virtual unsigned int
7873   do_first_plt_entry_offset() const
7874   { return sizeof(first_plt_entry); }
7875
7876   virtual void
7877   do_fill_first_plt_entry(unsigned char* pov,
7878                           Arm_address got_address,
7879                           Arm_address plt_address);
7880
7881  private:
7882   // Template for the first PLT entry.
7883   static const uint32_t first_plt_entry[5];
7884 };
7885
7886 // ARM PLTs.
7887 // FIXME:  This is not very flexible.  Right now this has only been tested
7888 // on armv5te.  If we are to support additional architecture features like
7889 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7890
7891 // The first entry in the PLT.
7892 template<bool big_endian>
7893 const uint32_t Output_data_plt_arm_standard<big_endian>::first_plt_entry[5] =
7894 {
7895   0xe52de004,   // str   lr, [sp, #-4]!
7896   0xe59fe004,   // ldr   lr, [pc, #4]
7897   0xe08fe00e,   // add   lr, pc, lr
7898   0xe5bef008,   // ldr   pc, [lr, #8]!
7899   0x00000000,   // &GOT[0] - .
7900 };
7901
7902 template<bool big_endian>
7903 void
7904 Output_data_plt_arm_standard<big_endian>::do_fill_first_plt_entry(
7905     unsigned char* pov,
7906     Arm_address got_address,
7907     Arm_address plt_address)
7908 {
7909   // Write first PLT entry.  All but the last word are constants.
7910   const size_t num_first_plt_words = (sizeof(first_plt_entry)
7911                                       / sizeof(first_plt_entry[0]));
7912   for (size_t i = 0; i < num_first_plt_words - 1; i++)
7913     {
7914       if (parameters->options().be8())
7915         {
7916           elfcpp::Swap<32, false>::writeval(pov + i * 4,
7917                                             first_plt_entry[i]);
7918         }
7919       else
7920         {
7921           elfcpp::Swap<32, big_endian>::writeval(pov + i * 4,
7922                                                  first_plt_entry[i]);
7923         }
7924     }
7925   // Last word in first PLT entry is &GOT[0] - .
7926   elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7927                                          got_address - (plt_address + 16));
7928 }
7929
7930 // Subsequent entries in the PLT.
7931 // This class generates short (12-byte) entries, for displacements up to 2^28.
7932
7933 template<bool big_endian>
7934 class Output_data_plt_arm_short : public Output_data_plt_arm_standard<big_endian>
7935 {
7936  public:
7937   Output_data_plt_arm_short(Layout* layout,
7938                             Arm_output_data_got<big_endian>* got,
7939                             Output_data_space* got_plt,
7940                             Output_data_space* got_irelative)
7941     : Output_data_plt_arm_standard<big_endian>(layout, got, got_plt, got_irelative)
7942   { }
7943
7944  protected:
7945   // Return the size of a PLT entry.
7946   virtual unsigned int
7947   do_get_plt_entry_size() const
7948   { return sizeof(plt_entry); }
7949
7950   virtual void
7951   do_fill_plt_entry(unsigned char* pov,
7952                     Arm_address got_address,
7953                     Arm_address plt_address,
7954                     unsigned int got_offset,
7955                     unsigned int plt_offset);
7956
7957  private:
7958   // Template for subsequent PLT entries.
7959   static const uint32_t plt_entry[3];
7960 };
7961
7962 template<bool big_endian>
7963 const uint32_t Output_data_plt_arm_short<big_endian>::plt_entry[3] =
7964 {
7965   0xe28fc600,   // add   ip, pc, #0xNN00000
7966   0xe28cca00,   // add   ip, ip, #0xNN000
7967   0xe5bcf000,   // ldr   pc, [ip, #0xNNN]!
7968 };
7969
7970 template<bool big_endian>
7971 void
7972 Output_data_plt_arm_short<big_endian>::do_fill_plt_entry(
7973     unsigned char* pov,
7974     Arm_address got_address,
7975     Arm_address plt_address,
7976     unsigned int got_offset,
7977     unsigned int plt_offset)
7978 {
7979   int32_t offset = ((got_address + got_offset)
7980                     - (plt_address + plt_offset + 8));
7981   if (offset < 0 || offset > 0x0fffffff)
7982     gold_error(_("PLT offset too large, try linking with --long-plt"));
7983
7984   uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7985   uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7986   uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7987
7988   if (parameters->options().be8())
7989     {
7990       elfcpp::Swap<32, false>::writeval(pov, plt_insn0);
7991       elfcpp::Swap<32, false>::writeval(pov + 4, plt_insn1);
7992       elfcpp::Swap<32, false>::writeval(pov + 8, plt_insn2);
7993     }
7994   else
7995     {
7996       elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7997       elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7998       elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7999     }
8000 }
8001
8002 // This class generates long (16-byte) entries, for arbitrary displacements.
8003
8004 template<bool big_endian>
8005 class Output_data_plt_arm_long : public Output_data_plt_arm_standard<big_endian>
8006 {
8007  public:
8008   Output_data_plt_arm_long(Layout* layout,
8009                            Arm_output_data_got<big_endian>* got,
8010                            Output_data_space* got_plt,
8011                            Output_data_space* got_irelative)
8012     : Output_data_plt_arm_standard<big_endian>(layout, got, got_plt, got_irelative)
8013   { }
8014
8015  protected:
8016   // Return the size of a PLT entry.
8017   virtual unsigned int
8018   do_get_plt_entry_size() const
8019   { return sizeof(plt_entry); }
8020
8021   virtual void
8022   do_fill_plt_entry(unsigned char* pov,
8023                     Arm_address got_address,
8024                     Arm_address plt_address,
8025                     unsigned int got_offset,
8026                     unsigned int plt_offset);
8027
8028  private:
8029   // Template for subsequent PLT entries.
8030   static const uint32_t plt_entry[4];
8031 };
8032
8033 template<bool big_endian>
8034 const uint32_t Output_data_plt_arm_long<big_endian>::plt_entry[4] =
8035 {
8036   0xe28fc200,   // add   ip, pc, #0xN0000000
8037   0xe28cc600,   // add   ip, ip, #0xNN00000
8038   0xe28cca00,   // add   ip, ip, #0xNN000
8039   0xe5bcf000,   // ldr   pc, [ip, #0xNNN]!
8040 };
8041
8042 template<bool big_endian>
8043 void
8044 Output_data_plt_arm_long<big_endian>::do_fill_plt_entry(
8045     unsigned char* pov,
8046     Arm_address got_address,
8047     Arm_address plt_address,
8048     unsigned int got_offset,
8049     unsigned int plt_offset)
8050 {
8051   int32_t offset = ((got_address + got_offset)
8052                     - (plt_address + plt_offset + 8));
8053
8054   uint32_t plt_insn0 = plt_entry[0] | (offset >> 28);
8055   uint32_t plt_insn1 = plt_entry[1] | ((offset >> 20) & 0xff);
8056   uint32_t plt_insn2 = plt_entry[2] | ((offset >> 12) & 0xff);
8057   uint32_t plt_insn3 = plt_entry[3] | (offset & 0xfff);
8058
8059   if (parameters->options().be8())
8060     {
8061       elfcpp::Swap<32, false>::writeval(pov, plt_insn0);
8062       elfcpp::Swap<32, false>::writeval(pov + 4, plt_insn1);
8063       elfcpp::Swap<32, false>::writeval(pov + 8, plt_insn2);
8064       elfcpp::Swap<32, false>::writeval(pov + 12, plt_insn3);
8065     }
8066   else
8067     {
8068       elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
8069       elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
8070       elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
8071       elfcpp::Swap<32, big_endian>::writeval(pov + 12, plt_insn3);
8072     }
8073 }
8074
8075 // Write out the PLT.  This uses the hand-coded instructions above,
8076 // and adjusts them as needed.  This is all specified by the arm ELF
8077 // Processor Supplement.
8078
8079 template<bool big_endian>
8080 void
8081 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
8082 {
8083   const off_t offset = this->offset();
8084   const section_size_type oview_size =
8085     convert_to_section_size_type(this->data_size());
8086   unsigned char* const oview = of->get_output_view(offset, oview_size);
8087
8088   const off_t got_file_offset = this->got_plt_->offset();
8089   gold_assert(got_file_offset + this->got_plt_->data_size()
8090               == this->got_irelative_->offset());
8091   const section_size_type got_size =
8092     convert_to_section_size_type(this->got_plt_->data_size()
8093                                  + this->got_irelative_->data_size());
8094   unsigned char* const got_view = of->get_output_view(got_file_offset,
8095                                                       got_size);
8096   unsigned char* pov = oview;
8097
8098   Arm_address plt_address = this->address();
8099   Arm_address got_address = this->got_plt_->address();
8100
8101   // Write first PLT entry.
8102   this->fill_first_plt_entry(pov, got_address, plt_address);
8103   pov += this->first_plt_entry_offset();
8104
8105   unsigned char* got_pov = got_view;
8106
8107   memset(got_pov, 0, 12);
8108   got_pov += 12;
8109
8110   unsigned int plt_offset = this->first_plt_entry_offset();
8111   unsigned int got_offset = 12;
8112   const unsigned int count = this->count_ + this->irelative_count_;
8113   gold_assert(this->irelative_count_ == this->irelative_data_vec_.size());
8114   for (unsigned int i = 0;
8115        i < count;
8116        ++i,
8117          pov += this->get_plt_entry_size(),
8118          got_pov += 4,
8119          plt_offset += this->get_plt_entry_size(),
8120          got_offset += 4)
8121     {
8122       // Set and adjust the PLT entry itself.
8123       this->fill_plt_entry(pov, got_address, plt_address,
8124                            got_offset, plt_offset);
8125
8126       Arm_address value;
8127       if (i < this->count_)
8128         {
8129           // For non-irelative got entries, the value is the beginning of plt.
8130           value = plt_address;
8131         }
8132       else
8133         {
8134           // For irelative got entries, the value is the (global/local) symbol
8135           // address.
8136           const IRelative_data& idata =
8137               this->irelative_data_vec_[i - this->count_];
8138           if (idata.symbol_is_global_)
8139             {
8140               // Set the entry in the GOT for irelative symbols.  The content is
8141               // the address of the ifunc, not the address of plt start.
8142               const Sized_symbol<32>* sized_symbol = idata.u_.global;
8143               gold_assert(sized_symbol->type() == elfcpp::STT_GNU_IFUNC);
8144               value = sized_symbol->value();
8145             }
8146           else
8147             {
8148               value = idata.u_.local.relobj->local_symbol_value(
8149                   idata.u_.local.index, 0);
8150             }
8151         }
8152       elfcpp::Swap<32, big_endian>::writeval(got_pov, value);
8153     }
8154
8155   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
8156   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
8157
8158   of->write_output_view(offset, oview_size, oview);
8159   of->write_output_view(got_file_offset, got_size, got_view);
8160 }
8161
8162
8163 // Create a PLT entry for a global symbol.
8164
8165 template<bool big_endian>
8166 void
8167 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
8168                                        Symbol* gsym)
8169 {
8170   if (gsym->has_plt_offset())
8171     return;
8172
8173   if (this->plt_ == NULL)
8174     this->make_plt_section(symtab, layout);
8175
8176   this->plt_->add_entry(symtab, layout, gsym);
8177 }
8178
8179
8180 // Create the PLT section.
8181 template<bool big_endian>
8182 void
8183 Target_arm<big_endian>::make_plt_section(
8184   Symbol_table* symtab, Layout* layout)
8185 {
8186   if (this->plt_ == NULL)
8187     {
8188       // Create the GOT section first.
8189       this->got_section(symtab, layout);
8190
8191       // GOT for irelatives is create along with got.plt.
8192       gold_assert(this->got_ != NULL
8193                   && this->got_plt_ != NULL
8194                   && this->got_irelative_ != NULL);
8195       this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_,
8196                                        this->got_irelative_);
8197
8198       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
8199                                       (elfcpp::SHF_ALLOC
8200                                        | elfcpp::SHF_EXECINSTR),
8201                                       this->plt_, ORDER_PLT, false);
8202       symtab->define_in_output_data("$a", NULL,
8203                                     Symbol_table::PREDEFINED,
8204                                     this->plt_,
8205                                     0, 0, elfcpp::STT_NOTYPE,
8206                                     elfcpp::STB_LOCAL,
8207                                     elfcpp::STV_DEFAULT, 0,
8208                                     false, false);
8209     }
8210 }
8211
8212
8213 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
8214
8215 template<bool big_endian>
8216 void
8217 Target_arm<big_endian>::make_local_ifunc_plt_entry(
8218     Symbol_table* symtab, Layout* layout,
8219     Sized_relobj_file<32, big_endian>* relobj,
8220     unsigned int local_sym_index)
8221 {
8222   if (relobj->local_has_plt_offset(local_sym_index))
8223     return;
8224   if (this->plt_ == NULL)
8225     this->make_plt_section(symtab, layout);
8226   unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
8227                                                               relobj,
8228                                                               local_sym_index);
8229   relobj->set_local_plt_offset(local_sym_index, plt_offset);
8230 }
8231
8232
8233 // Return the number of entries in the PLT.
8234
8235 template<bool big_endian>
8236 unsigned int
8237 Target_arm<big_endian>::plt_entry_count() const
8238 {
8239   if (this->plt_ == NULL)
8240     return 0;
8241   return this->plt_->entry_count();
8242 }
8243
8244 // Return the offset of the first non-reserved PLT entry.
8245
8246 template<bool big_endian>
8247 unsigned int
8248 Target_arm<big_endian>::first_plt_entry_offset() const
8249 {
8250   return this->plt_->first_plt_entry_offset();
8251 }
8252
8253 // Return the size of each PLT entry.
8254
8255 template<bool big_endian>
8256 unsigned int
8257 Target_arm<big_endian>::plt_entry_size() const
8258 {
8259   return this->plt_->get_plt_entry_size();
8260 }
8261
8262 // Get the section to use for TLS_DESC relocations.
8263
8264 template<bool big_endian>
8265 typename Target_arm<big_endian>::Reloc_section*
8266 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
8267 {
8268   return this->plt_section()->rel_tls_desc(layout);
8269 }
8270
8271 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
8272
8273 template<bool big_endian>
8274 void
8275 Target_arm<big_endian>::define_tls_base_symbol(
8276     Symbol_table* symtab,
8277     Layout* layout)
8278 {
8279   if (this->tls_base_symbol_defined_)
8280     return;
8281
8282   Output_segment* tls_segment = layout->tls_segment();
8283   if (tls_segment != NULL)
8284     {
8285       bool is_exec = parameters->options().output_is_executable();
8286       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
8287                                        Symbol_table::PREDEFINED,
8288                                        tls_segment, 0, 0,
8289                                        elfcpp::STT_TLS,
8290                                        elfcpp::STB_LOCAL,
8291                                        elfcpp::STV_HIDDEN, 0,
8292                                        (is_exec
8293                                         ? Symbol::SEGMENT_END
8294                                         : Symbol::SEGMENT_START),
8295                                        true);
8296     }
8297   this->tls_base_symbol_defined_ = true;
8298 }
8299
8300 // Create a GOT entry for the TLS module index.
8301
8302 template<bool big_endian>
8303 unsigned int
8304 Target_arm<big_endian>::got_mod_index_entry(
8305     Symbol_table* symtab,
8306     Layout* layout,
8307     Sized_relobj_file<32, big_endian>* object)
8308 {
8309   if (this->got_mod_index_offset_ == -1U)
8310     {
8311       gold_assert(symtab != NULL && layout != NULL && object != NULL);
8312       Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
8313       unsigned int got_offset;
8314       if (!parameters->doing_static_link())
8315         {
8316           got_offset = got->add_constant(0);
8317           Reloc_section* rel_dyn = this->rel_dyn_section(layout);
8318           rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
8319                              got_offset);
8320         }
8321       else
8322         {
8323           // We are doing a static link.  Just mark it as belong to module 1,
8324           // the executable.
8325           got_offset = got->add_constant(1);
8326         }
8327
8328       got->add_constant(0);
8329       this->got_mod_index_offset_ = got_offset;
8330     }
8331   return this->got_mod_index_offset_;
8332 }
8333
8334 // Optimize the TLS relocation type based on what we know about the
8335 // symbol.  IS_FINAL is true if the final address of this symbol is
8336 // known at link time.
8337
8338 template<bool big_endian>
8339 tls::Tls_optimization
8340 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
8341 {
8342   // FIXME: Currently we do not do any TLS optimization.
8343   return tls::TLSOPT_NONE;
8344 }
8345
8346 // Get the Reference_flags for a particular relocation.
8347
8348 template<bool big_endian>
8349 int
8350 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
8351 {
8352   switch (r_type)
8353     {
8354     case elfcpp::R_ARM_NONE:
8355     case elfcpp::R_ARM_V4BX:
8356     case elfcpp::R_ARM_GNU_VTENTRY:
8357     case elfcpp::R_ARM_GNU_VTINHERIT:
8358       // No symbol reference.
8359       return 0;
8360
8361     case elfcpp::R_ARM_ABS32:
8362     case elfcpp::R_ARM_ABS16:
8363     case elfcpp::R_ARM_ABS12:
8364     case elfcpp::R_ARM_THM_ABS5:
8365     case elfcpp::R_ARM_ABS8:
8366     case elfcpp::R_ARM_BASE_ABS:
8367     case elfcpp::R_ARM_MOVW_ABS_NC:
8368     case elfcpp::R_ARM_MOVT_ABS:
8369     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8370     case elfcpp::R_ARM_THM_MOVT_ABS:
8371     case elfcpp::R_ARM_ABS32_NOI:
8372       return Symbol::ABSOLUTE_REF;
8373
8374     case elfcpp::R_ARM_REL32:
8375     case elfcpp::R_ARM_LDR_PC_G0:
8376     case elfcpp::R_ARM_SBREL32:
8377     case elfcpp::R_ARM_THM_PC8:
8378     case elfcpp::R_ARM_BASE_PREL:
8379     case elfcpp::R_ARM_MOVW_PREL_NC:
8380     case elfcpp::R_ARM_MOVT_PREL:
8381     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8382     case elfcpp::R_ARM_THM_MOVT_PREL:
8383     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8384     case elfcpp::R_ARM_THM_PC12:
8385     case elfcpp::R_ARM_REL32_NOI:
8386     case elfcpp::R_ARM_ALU_PC_G0_NC:
8387     case elfcpp::R_ARM_ALU_PC_G0:
8388     case elfcpp::R_ARM_ALU_PC_G1_NC:
8389     case elfcpp::R_ARM_ALU_PC_G1:
8390     case elfcpp::R_ARM_ALU_PC_G2:
8391     case elfcpp::R_ARM_LDR_PC_G1:
8392     case elfcpp::R_ARM_LDR_PC_G2:
8393     case elfcpp::R_ARM_LDRS_PC_G0:
8394     case elfcpp::R_ARM_LDRS_PC_G1:
8395     case elfcpp::R_ARM_LDRS_PC_G2:
8396     case elfcpp::R_ARM_LDC_PC_G0:
8397     case elfcpp::R_ARM_LDC_PC_G1:
8398     case elfcpp::R_ARM_LDC_PC_G2:
8399     case elfcpp::R_ARM_ALU_SB_G0_NC:
8400     case elfcpp::R_ARM_ALU_SB_G0:
8401     case elfcpp::R_ARM_ALU_SB_G1_NC:
8402     case elfcpp::R_ARM_ALU_SB_G1:
8403     case elfcpp::R_ARM_ALU_SB_G2:
8404     case elfcpp::R_ARM_LDR_SB_G0:
8405     case elfcpp::R_ARM_LDR_SB_G1:
8406     case elfcpp::R_ARM_LDR_SB_G2:
8407     case elfcpp::R_ARM_LDRS_SB_G0:
8408     case elfcpp::R_ARM_LDRS_SB_G1:
8409     case elfcpp::R_ARM_LDRS_SB_G2:
8410     case elfcpp::R_ARM_LDC_SB_G0:
8411     case elfcpp::R_ARM_LDC_SB_G1:
8412     case elfcpp::R_ARM_LDC_SB_G2:
8413     case elfcpp::R_ARM_MOVW_BREL_NC:
8414     case elfcpp::R_ARM_MOVT_BREL:
8415     case elfcpp::R_ARM_MOVW_BREL:
8416     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8417     case elfcpp::R_ARM_THM_MOVT_BREL:
8418     case elfcpp::R_ARM_THM_MOVW_BREL:
8419     case elfcpp::R_ARM_GOTOFF32:
8420     case elfcpp::R_ARM_GOTOFF12:
8421     case elfcpp::R_ARM_SBREL31:
8422       return Symbol::RELATIVE_REF;
8423
8424     case elfcpp::R_ARM_PLT32:
8425     case elfcpp::R_ARM_CALL:
8426     case elfcpp::R_ARM_JUMP24:
8427     case elfcpp::R_ARM_THM_CALL:
8428     case elfcpp::R_ARM_THM_JUMP24:
8429     case elfcpp::R_ARM_THM_JUMP19:
8430     case elfcpp::R_ARM_THM_JUMP6:
8431     case elfcpp::R_ARM_THM_JUMP11:
8432     case elfcpp::R_ARM_THM_JUMP8:
8433     // R_ARM_PREL31 is not used to relocate call/jump instructions but
8434     // in unwind tables. It may point to functions via PLTs.
8435     // So we treat it like call/jump relocations above.
8436     case elfcpp::R_ARM_PREL31:
8437       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
8438
8439     case elfcpp::R_ARM_GOT_BREL:
8440     case elfcpp::R_ARM_GOT_ABS:
8441     case elfcpp::R_ARM_GOT_PREL:
8442       // Absolute in GOT.
8443       return Symbol::ABSOLUTE_REF;
8444
8445     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8446     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8447     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8448     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8449     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8450       return Symbol::TLS_REF;
8451
8452     case elfcpp::R_ARM_TARGET1:
8453     case elfcpp::R_ARM_TARGET2:
8454     case elfcpp::R_ARM_COPY:
8455     case elfcpp::R_ARM_GLOB_DAT:
8456     case elfcpp::R_ARM_JUMP_SLOT:
8457     case elfcpp::R_ARM_RELATIVE:
8458     case elfcpp::R_ARM_PC24:
8459     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8460     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8461     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8462     default:
8463       // Not expected.  We will give an error later.
8464       return 0;
8465     }
8466 }
8467
8468 // Report an unsupported relocation against a local symbol.
8469
8470 template<bool big_endian>
8471 void
8472 Target_arm<big_endian>::Scan::unsupported_reloc_local(
8473     Sized_relobj_file<32, big_endian>* object,
8474     unsigned int r_type)
8475 {
8476   gold_error(_("%s: unsupported reloc %u against local symbol"),
8477              object->name().c_str(), r_type);
8478 }
8479
8480 // We are about to emit a dynamic relocation of type R_TYPE.  If the
8481 // dynamic linker does not support it, issue an error.  The GNU linker
8482 // only issues a non-PIC error for an allocated read-only section.
8483 // Here we know the section is allocated, but we don't know that it is
8484 // read-only.  But we check for all the relocation types which the
8485 // glibc dynamic linker supports, so it seems appropriate to issue an
8486 // error even if the section is not read-only.
8487
8488 template<bool big_endian>
8489 void
8490 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
8491                                             unsigned int r_type)
8492 {
8493   switch (r_type)
8494     {
8495     // These are the relocation types supported by glibc for ARM.
8496     case elfcpp::R_ARM_RELATIVE:
8497     case elfcpp::R_ARM_COPY:
8498     case elfcpp::R_ARM_GLOB_DAT:
8499     case elfcpp::R_ARM_JUMP_SLOT:
8500     case elfcpp::R_ARM_ABS32:
8501     case elfcpp::R_ARM_ABS32_NOI:
8502     case elfcpp::R_ARM_IRELATIVE:
8503     case elfcpp::R_ARM_PC24:
8504     // FIXME: The following 3 types are not supported by Android's dynamic
8505     // linker.
8506     case elfcpp::R_ARM_TLS_DTPMOD32:
8507     case elfcpp::R_ARM_TLS_DTPOFF32:
8508     case elfcpp::R_ARM_TLS_TPOFF32:
8509       return;
8510
8511     default:
8512       {
8513         // This prevents us from issuing more than one error per reloc
8514         // section.  But we can still wind up issuing more than one
8515         // error per object file.
8516         if (this->issued_non_pic_error_)
8517           return;
8518         const Arm_reloc_property* reloc_property =
8519           arm_reloc_property_table->get_reloc_property(r_type);
8520         gold_assert(reloc_property != NULL);
8521         object->error(_("requires unsupported dynamic reloc %s; "
8522                       "recompile with -fPIC"),
8523                       reloc_property->name().c_str());
8524         this->issued_non_pic_error_ = true;
8525         return;
8526       }
8527
8528     case elfcpp::R_ARM_NONE:
8529       gold_unreachable();
8530     }
8531 }
8532
8533
8534 // Return whether we need to make a PLT entry for a relocation of the
8535 // given type against a STT_GNU_IFUNC symbol.
8536
8537 template<bool big_endian>
8538 bool
8539 Target_arm<big_endian>::Scan::reloc_needs_plt_for_ifunc(
8540     Sized_relobj_file<32, big_endian>* object,
8541     unsigned int r_type)
8542 {
8543   int flags = Scan::get_reference_flags(r_type);
8544   if (flags & Symbol::TLS_REF)
8545     {
8546       gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
8547                  object->name().c_str(), r_type);
8548       return false;
8549     }
8550   return flags != 0;
8551 }
8552
8553
8554 // Scan a relocation for a local symbol.
8555 // FIXME: This only handles a subset of relocation types used by Android
8556 // on ARM v5te devices.
8557
8558 template<bool big_endian>
8559 inline void
8560 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
8561                                     Layout* layout,
8562                                     Target_arm* target,
8563                                     Sized_relobj_file<32, big_endian>* object,
8564                                     unsigned int data_shndx,
8565                                     Output_section* output_section,
8566                                     const elfcpp::Rel<32, big_endian>& reloc,
8567                                     unsigned int r_type,
8568                                     const elfcpp::Sym<32, big_endian>& lsym,
8569                                     bool is_discarded)
8570 {
8571   if (is_discarded)
8572     return;
8573
8574   r_type = target->get_real_reloc_type(r_type);
8575
8576   // A local STT_GNU_IFUNC symbol may require a PLT entry.
8577   bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
8578   if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
8579     {
8580       unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8581       target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
8582     }
8583
8584   switch (r_type)
8585     {
8586     case elfcpp::R_ARM_NONE:
8587     case elfcpp::R_ARM_V4BX:
8588     case elfcpp::R_ARM_GNU_VTENTRY:
8589     case elfcpp::R_ARM_GNU_VTINHERIT:
8590       break;
8591
8592     case elfcpp::R_ARM_ABS32:
8593     case elfcpp::R_ARM_ABS32_NOI:
8594       // If building a shared library (or a position-independent
8595       // executable), we need to create a dynamic relocation for
8596       // this location. The relocation applied at link time will
8597       // apply the link-time value, so we flag the location with
8598       // an R_ARM_RELATIVE relocation so the dynamic loader can
8599       // relocate it easily.
8600       if (parameters->options().output_is_position_independent())
8601         {
8602           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8603           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8604           // If we are to add more other reloc types than R_ARM_ABS32,
8605           // we need to add check_non_pic(object, r_type) here.
8606           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
8607                                       output_section, data_shndx,
8608                                       reloc.get_r_offset(), is_ifunc);
8609         }
8610       break;
8611
8612     case elfcpp::R_ARM_ABS16:
8613     case elfcpp::R_ARM_ABS12:
8614     case elfcpp::R_ARM_THM_ABS5:
8615     case elfcpp::R_ARM_ABS8:
8616     case elfcpp::R_ARM_BASE_ABS:
8617     case elfcpp::R_ARM_MOVW_ABS_NC:
8618     case elfcpp::R_ARM_MOVT_ABS:
8619     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8620     case elfcpp::R_ARM_THM_MOVT_ABS:
8621       // If building a shared library (or a position-independent
8622       // executable), we need to create a dynamic relocation for
8623       // this location. Because the addend needs to remain in the
8624       // data section, we need to be careful not to apply this
8625       // relocation statically.
8626       if (parameters->options().output_is_position_independent())
8627         {
8628           check_non_pic(object, r_type);
8629           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8630           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8631           if (lsym.get_st_type() != elfcpp::STT_SECTION)
8632             rel_dyn->add_local(object, r_sym, r_type, output_section,
8633                                data_shndx, reloc.get_r_offset());
8634           else
8635             {
8636               gold_assert(lsym.get_st_value() == 0);
8637               unsigned int shndx = lsym.get_st_shndx();
8638               bool is_ordinary;
8639               shndx = object->adjust_sym_shndx(r_sym, shndx,
8640                                                &is_ordinary);
8641               if (!is_ordinary)
8642                 object->error(_("section symbol %u has bad shndx %u"),
8643                               r_sym, shndx);
8644               else
8645                 rel_dyn->add_local_section(object, shndx,
8646                                            r_type, output_section,
8647                                            data_shndx, reloc.get_r_offset());
8648             }
8649         }
8650       break;
8651
8652     case elfcpp::R_ARM_REL32:
8653     case elfcpp::R_ARM_LDR_PC_G0:
8654     case elfcpp::R_ARM_SBREL32:
8655     case elfcpp::R_ARM_THM_CALL:
8656     case elfcpp::R_ARM_THM_PC8:
8657     case elfcpp::R_ARM_BASE_PREL:
8658     case elfcpp::R_ARM_PLT32:
8659     case elfcpp::R_ARM_CALL:
8660     case elfcpp::R_ARM_JUMP24:
8661     case elfcpp::R_ARM_THM_JUMP24:
8662     case elfcpp::R_ARM_SBREL31:
8663     case elfcpp::R_ARM_PREL31:
8664     case elfcpp::R_ARM_MOVW_PREL_NC:
8665     case elfcpp::R_ARM_MOVT_PREL:
8666     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8667     case elfcpp::R_ARM_THM_MOVT_PREL:
8668     case elfcpp::R_ARM_THM_JUMP19:
8669     case elfcpp::R_ARM_THM_JUMP6:
8670     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8671     case elfcpp::R_ARM_THM_PC12:
8672     case elfcpp::R_ARM_REL32_NOI:
8673     case elfcpp::R_ARM_ALU_PC_G0_NC:
8674     case elfcpp::R_ARM_ALU_PC_G0:
8675     case elfcpp::R_ARM_ALU_PC_G1_NC:
8676     case elfcpp::R_ARM_ALU_PC_G1:
8677     case elfcpp::R_ARM_ALU_PC_G2:
8678     case elfcpp::R_ARM_LDR_PC_G1:
8679     case elfcpp::R_ARM_LDR_PC_G2:
8680     case elfcpp::R_ARM_LDRS_PC_G0:
8681     case elfcpp::R_ARM_LDRS_PC_G1:
8682     case elfcpp::R_ARM_LDRS_PC_G2:
8683     case elfcpp::R_ARM_LDC_PC_G0:
8684     case elfcpp::R_ARM_LDC_PC_G1:
8685     case elfcpp::R_ARM_LDC_PC_G2:
8686     case elfcpp::R_ARM_ALU_SB_G0_NC:
8687     case elfcpp::R_ARM_ALU_SB_G0:
8688     case elfcpp::R_ARM_ALU_SB_G1_NC:
8689     case elfcpp::R_ARM_ALU_SB_G1:
8690     case elfcpp::R_ARM_ALU_SB_G2:
8691     case elfcpp::R_ARM_LDR_SB_G0:
8692     case elfcpp::R_ARM_LDR_SB_G1:
8693     case elfcpp::R_ARM_LDR_SB_G2:
8694     case elfcpp::R_ARM_LDRS_SB_G0:
8695     case elfcpp::R_ARM_LDRS_SB_G1:
8696     case elfcpp::R_ARM_LDRS_SB_G2:
8697     case elfcpp::R_ARM_LDC_SB_G0:
8698     case elfcpp::R_ARM_LDC_SB_G1:
8699     case elfcpp::R_ARM_LDC_SB_G2:
8700     case elfcpp::R_ARM_MOVW_BREL_NC:
8701     case elfcpp::R_ARM_MOVT_BREL:
8702     case elfcpp::R_ARM_MOVW_BREL:
8703     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8704     case elfcpp::R_ARM_THM_MOVT_BREL:
8705     case elfcpp::R_ARM_THM_MOVW_BREL:
8706     case elfcpp::R_ARM_THM_JUMP11:
8707     case elfcpp::R_ARM_THM_JUMP8:
8708       // We don't need to do anything for a relative addressing relocation
8709       // against a local symbol if it does not reference the GOT.
8710       break;
8711
8712     case elfcpp::R_ARM_GOTOFF32:
8713     case elfcpp::R_ARM_GOTOFF12:
8714       // We need a GOT section:
8715       target->got_section(symtab, layout);
8716       break;
8717
8718     case elfcpp::R_ARM_GOT_BREL:
8719     case elfcpp::R_ARM_GOT_PREL:
8720       {
8721         // The symbol requires a GOT entry.
8722         Arm_output_data_got<big_endian>* got =
8723           target->got_section(symtab, layout);
8724         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8725         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
8726           {
8727             // If we are generating a shared object, we need to add a
8728             // dynamic RELATIVE relocation for this symbol's GOT entry.
8729             if (parameters->options().output_is_position_independent())
8730               {
8731                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8732                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8733                 rel_dyn->add_local_relative(
8734                     object, r_sym, elfcpp::R_ARM_RELATIVE, got,
8735                     object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
8736               }
8737           }
8738       }
8739       break;
8740
8741     case elfcpp::R_ARM_TARGET1:
8742     case elfcpp::R_ARM_TARGET2:
8743       // This should have been mapped to another type already.
8744       // Fall through.
8745     case elfcpp::R_ARM_COPY:
8746     case elfcpp::R_ARM_GLOB_DAT:
8747     case elfcpp::R_ARM_JUMP_SLOT:
8748     case elfcpp::R_ARM_RELATIVE:
8749       // These are relocations which should only be seen by the
8750       // dynamic linker, and should never be seen here.
8751       gold_error(_("%s: unexpected reloc %u in object file"),
8752                  object->name().c_str(), r_type);
8753       break;
8754
8755
8756       // These are initial TLS relocs, which are expected when
8757       // linking.
8758     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8759     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8760     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8761     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8762     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8763       {
8764         bool output_is_shared = parameters->options().shared();
8765         const tls::Tls_optimization optimized_type
8766             = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
8767                                                          r_type);
8768         switch (r_type)
8769           {
8770           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8771             if (optimized_type == tls::TLSOPT_NONE)
8772               {
8773                 // Create a pair of GOT entries for the module index and
8774                 // dtv-relative offset.
8775                 Arm_output_data_got<big_endian>* got
8776                     = target->got_section(symtab, layout);
8777                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8778                 unsigned int shndx = lsym.get_st_shndx();
8779                 bool is_ordinary;
8780                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
8781                 if (!is_ordinary)
8782                   {
8783                     object->error(_("local symbol %u has bad shndx %u"),
8784                                   r_sym, shndx);
8785                     break;
8786                   }
8787
8788                 if (!parameters->doing_static_link())
8789                   got->add_local_pair_with_rel(object, r_sym, shndx,
8790                                                GOT_TYPE_TLS_PAIR,
8791                                                target->rel_dyn_section(layout),
8792                                                elfcpp::R_ARM_TLS_DTPMOD32);
8793                 else
8794                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
8795                                                       object, r_sym);
8796               }
8797             else
8798               // FIXME: TLS optimization not supported yet.
8799               gold_unreachable();
8800             break;
8801
8802           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
8803             if (optimized_type == tls::TLSOPT_NONE)
8804               {
8805                 // Create a GOT entry for the module index.
8806                 target->got_mod_index_entry(symtab, layout, object);
8807               }
8808             else
8809               // FIXME: TLS optimization not supported yet.
8810               gold_unreachable();
8811             break;
8812
8813           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
8814             break;
8815
8816           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
8817             layout->set_has_static_tls();
8818             if (optimized_type == tls::TLSOPT_NONE)
8819               {
8820                 // Create a GOT entry for the tp-relative offset.
8821                 Arm_output_data_got<big_endian>* got
8822                   = target->got_section(symtab, layout);
8823                 unsigned int r_sym =
8824                    elfcpp::elf_r_sym<32>(reloc.get_r_info());
8825                 if (!parameters->doing_static_link())
8826                     got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
8827                                             target->rel_dyn_section(layout),
8828                                             elfcpp::R_ARM_TLS_TPOFF32);
8829                 else if (!object->local_has_got_offset(r_sym,
8830                                                        GOT_TYPE_TLS_OFFSET))
8831                   {
8832                     got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
8833                     unsigned int got_offset =
8834                       object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
8835                     got->add_static_reloc(got_offset,
8836                                           elfcpp::R_ARM_TLS_TPOFF32, object,
8837                                           r_sym);
8838                   }
8839               }
8840             else
8841               // FIXME: TLS optimization not supported yet.
8842               gold_unreachable();
8843             break;
8844
8845           case elfcpp::R_ARM_TLS_LE32:          // Local-exec
8846             layout->set_has_static_tls();
8847             if (output_is_shared)
8848               {
8849                 // We need to create a dynamic relocation.
8850                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8851                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8852                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8853                 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8854                                    output_section, data_shndx,
8855                                    reloc.get_r_offset());
8856               }
8857             break;
8858
8859           default:
8860             gold_unreachable();
8861           }
8862       }
8863       break;
8864
8865     case elfcpp::R_ARM_PC24:
8866     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8867     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8868     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8869     default:
8870       unsupported_reloc_local(object, r_type);
8871       break;
8872     }
8873 }
8874
8875 // Report an unsupported relocation against a global symbol.
8876
8877 template<bool big_endian>
8878 void
8879 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8880     Sized_relobj_file<32, big_endian>* object,
8881     unsigned int r_type,
8882     Symbol* gsym)
8883 {
8884   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8885              object->name().c_str(), r_type, gsym->demangled_name().c_str());
8886 }
8887
8888 template<bool big_endian>
8889 inline bool
8890 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8891     unsigned int r_type)
8892 {
8893   switch (r_type)
8894     {
8895     case elfcpp::R_ARM_PC24:
8896     case elfcpp::R_ARM_THM_CALL:
8897     case elfcpp::R_ARM_PLT32:
8898     case elfcpp::R_ARM_CALL:
8899     case elfcpp::R_ARM_JUMP24:
8900     case elfcpp::R_ARM_THM_JUMP24:
8901     case elfcpp::R_ARM_SBREL31:
8902     case elfcpp::R_ARM_PREL31:
8903     case elfcpp::R_ARM_THM_JUMP19:
8904     case elfcpp::R_ARM_THM_JUMP6:
8905     case elfcpp::R_ARM_THM_JUMP11:
8906     case elfcpp::R_ARM_THM_JUMP8:
8907       // All the relocations above are branches except SBREL31 and PREL31.
8908       return false;
8909
8910     default:
8911       // Be conservative and assume this is a function pointer.
8912       return true;
8913     }
8914 }
8915
8916 template<bool big_endian>
8917 inline bool
8918 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8919   Symbol_table*,
8920   Layout*,
8921   Target_arm<big_endian>* target,
8922   Sized_relobj_file<32, big_endian>*,
8923   unsigned int,
8924   Output_section*,
8925   const elfcpp::Rel<32, big_endian>&,
8926   unsigned int r_type,
8927   const elfcpp::Sym<32, big_endian>&)
8928 {
8929   r_type = target->get_real_reloc_type(r_type);
8930   return possible_function_pointer_reloc(r_type);
8931 }
8932
8933 template<bool big_endian>
8934 inline bool
8935 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8936   Symbol_table*,
8937   Layout*,
8938   Target_arm<big_endian>* target,
8939   Sized_relobj_file<32, big_endian>*,
8940   unsigned int,
8941   Output_section*,
8942   const elfcpp::Rel<32, big_endian>&,
8943   unsigned int r_type,
8944   Symbol* gsym)
8945 {
8946   // GOT is not a function.
8947   if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8948     return false;
8949
8950   r_type = target->get_real_reloc_type(r_type);
8951   return possible_function_pointer_reloc(r_type);
8952 }
8953
8954 // Scan a relocation for a global symbol.
8955
8956 template<bool big_endian>
8957 inline void
8958 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8959                                      Layout* layout,
8960                                      Target_arm* target,
8961                                      Sized_relobj_file<32, big_endian>* object,
8962                                      unsigned int data_shndx,
8963                                      Output_section* output_section,
8964                                      const elfcpp::Rel<32, big_endian>& reloc,
8965                                      unsigned int r_type,
8966                                      Symbol* gsym)
8967 {
8968   // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8969   // section.  We check here to avoid creating a dynamic reloc against
8970   // _GLOBAL_OFFSET_TABLE_.
8971   if (!target->has_got_section()
8972       && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8973     target->got_section(symtab, layout);
8974
8975   // A STT_GNU_IFUNC symbol may require a PLT entry.
8976   if (gsym->type() == elfcpp::STT_GNU_IFUNC
8977       && this->reloc_needs_plt_for_ifunc(object, r_type))
8978     target->make_plt_entry(symtab, layout, gsym);
8979
8980   r_type = target->get_real_reloc_type(r_type);
8981   switch (r_type)
8982     {
8983     case elfcpp::R_ARM_NONE:
8984     case elfcpp::R_ARM_V4BX:
8985     case elfcpp::R_ARM_GNU_VTENTRY:
8986     case elfcpp::R_ARM_GNU_VTINHERIT:
8987       break;
8988
8989     case elfcpp::R_ARM_ABS32:
8990     case elfcpp::R_ARM_ABS16:
8991     case elfcpp::R_ARM_ABS12:
8992     case elfcpp::R_ARM_THM_ABS5:
8993     case elfcpp::R_ARM_ABS8:
8994     case elfcpp::R_ARM_BASE_ABS:
8995     case elfcpp::R_ARM_MOVW_ABS_NC:
8996     case elfcpp::R_ARM_MOVT_ABS:
8997     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8998     case elfcpp::R_ARM_THM_MOVT_ABS:
8999     case elfcpp::R_ARM_ABS32_NOI:
9000       // Absolute addressing relocations.
9001       {
9002         // Make a PLT entry if necessary.
9003         if (this->symbol_needs_plt_entry(gsym))
9004           {
9005             target->make_plt_entry(symtab, layout, gsym);
9006             // Since this is not a PC-relative relocation, we may be
9007             // taking the address of a function. In that case we need to
9008             // set the entry in the dynamic symbol table to the address of
9009             // the PLT entry.
9010             if (gsym->is_from_dynobj() && !parameters->options().shared())
9011               gsym->set_needs_dynsym_value();
9012           }
9013         // Make a dynamic relocation if necessary.
9014         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
9015           {
9016             if (!parameters->options().output_is_position_independent()
9017                 && gsym->may_need_copy_reloc())
9018               {
9019                 target->copy_reloc(symtab, layout, object,
9020                                    data_shndx, output_section, gsym, reloc);
9021               }
9022             else if ((r_type == elfcpp::R_ARM_ABS32
9023                       || r_type == elfcpp::R_ARM_ABS32_NOI)
9024                      && gsym->type() == elfcpp::STT_GNU_IFUNC
9025                      && gsym->can_use_relative_reloc(false)
9026                      && !gsym->is_from_dynobj()
9027                      && !gsym->is_undefined()
9028                      && !gsym->is_preemptible())
9029               {
9030                 // Use an IRELATIVE reloc for a locally defined STT_GNU_IFUNC
9031                 // symbol. This makes a function address in a PIE executable
9032                 // match the address in a shared library that it links against.
9033                 Reloc_section* rel_irelative =
9034                     target->rel_irelative_section(layout);
9035                 unsigned int r_type = elfcpp::R_ARM_IRELATIVE;
9036                 rel_irelative->add_symbolless_global_addend(
9037                     gsym, r_type, output_section, object,
9038                     data_shndx, reloc.get_r_offset());
9039               }
9040             else if ((r_type == elfcpp::R_ARM_ABS32
9041                       || r_type == elfcpp::R_ARM_ABS32_NOI)
9042                      && gsym->can_use_relative_reloc(false))
9043               {
9044                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
9045                 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
9046                                              output_section, object,
9047                                              data_shndx, reloc.get_r_offset());
9048               }
9049             else
9050               {
9051                 check_non_pic(object, r_type);
9052                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
9053                 rel_dyn->add_global(gsym, r_type, output_section, object,
9054                                     data_shndx, reloc.get_r_offset());
9055               }
9056           }
9057       }
9058       break;
9059
9060     case elfcpp::R_ARM_GOTOFF32:
9061     case elfcpp::R_ARM_GOTOFF12:
9062       // We need a GOT section.
9063       target->got_section(symtab, layout);
9064       break;
9065
9066     case elfcpp::R_ARM_REL32:
9067     case elfcpp::R_ARM_LDR_PC_G0:
9068     case elfcpp::R_ARM_SBREL32:
9069     case elfcpp::R_ARM_THM_PC8:
9070     case elfcpp::R_ARM_BASE_PREL:
9071     case elfcpp::R_ARM_MOVW_PREL_NC:
9072     case elfcpp::R_ARM_MOVT_PREL:
9073     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9074     case elfcpp::R_ARM_THM_MOVT_PREL:
9075     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9076     case elfcpp::R_ARM_THM_PC12:
9077     case elfcpp::R_ARM_REL32_NOI:
9078     case elfcpp::R_ARM_ALU_PC_G0_NC:
9079     case elfcpp::R_ARM_ALU_PC_G0:
9080     case elfcpp::R_ARM_ALU_PC_G1_NC:
9081     case elfcpp::R_ARM_ALU_PC_G1:
9082     case elfcpp::R_ARM_ALU_PC_G2:
9083     case elfcpp::R_ARM_LDR_PC_G1:
9084     case elfcpp::R_ARM_LDR_PC_G2:
9085     case elfcpp::R_ARM_LDRS_PC_G0:
9086     case elfcpp::R_ARM_LDRS_PC_G1:
9087     case elfcpp::R_ARM_LDRS_PC_G2:
9088     case elfcpp::R_ARM_LDC_PC_G0:
9089     case elfcpp::R_ARM_LDC_PC_G1:
9090     case elfcpp::R_ARM_LDC_PC_G2:
9091     case elfcpp::R_ARM_ALU_SB_G0_NC:
9092     case elfcpp::R_ARM_ALU_SB_G0:
9093     case elfcpp::R_ARM_ALU_SB_G1_NC:
9094     case elfcpp::R_ARM_ALU_SB_G1:
9095     case elfcpp::R_ARM_ALU_SB_G2:
9096     case elfcpp::R_ARM_LDR_SB_G0:
9097     case elfcpp::R_ARM_LDR_SB_G1:
9098     case elfcpp::R_ARM_LDR_SB_G2:
9099     case elfcpp::R_ARM_LDRS_SB_G0:
9100     case elfcpp::R_ARM_LDRS_SB_G1:
9101     case elfcpp::R_ARM_LDRS_SB_G2:
9102     case elfcpp::R_ARM_LDC_SB_G0:
9103     case elfcpp::R_ARM_LDC_SB_G1:
9104     case elfcpp::R_ARM_LDC_SB_G2:
9105     case elfcpp::R_ARM_MOVW_BREL_NC:
9106     case elfcpp::R_ARM_MOVT_BREL:
9107     case elfcpp::R_ARM_MOVW_BREL:
9108     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9109     case elfcpp::R_ARM_THM_MOVT_BREL:
9110     case elfcpp::R_ARM_THM_MOVW_BREL:
9111       // Relative addressing relocations.
9112       {
9113         // Make a dynamic relocation if necessary.
9114         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
9115           {
9116             if (parameters->options().output_is_executable()
9117                 && target->may_need_copy_reloc(gsym))
9118               {
9119                 target->copy_reloc(symtab, layout, object,
9120                                    data_shndx, output_section, gsym, reloc);
9121               }
9122             else
9123               {
9124                 check_non_pic(object, r_type);
9125                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
9126                 rel_dyn->add_global(gsym, r_type, output_section, object,
9127                                     data_shndx, reloc.get_r_offset());
9128               }
9129           }
9130       }
9131       break;
9132
9133     case elfcpp::R_ARM_THM_CALL:
9134     case elfcpp::R_ARM_PLT32:
9135     case elfcpp::R_ARM_CALL:
9136     case elfcpp::R_ARM_JUMP24:
9137     case elfcpp::R_ARM_THM_JUMP24:
9138     case elfcpp::R_ARM_SBREL31:
9139     case elfcpp::R_ARM_PREL31:
9140     case elfcpp::R_ARM_THM_JUMP19:
9141     case elfcpp::R_ARM_THM_JUMP6:
9142     case elfcpp::R_ARM_THM_JUMP11:
9143     case elfcpp::R_ARM_THM_JUMP8:
9144       // All the relocation above are branches except for the PREL31 ones.
9145       // A PREL31 relocation can point to a personality function in a shared
9146       // library.  In that case we want to use a PLT because we want to
9147       // call the personality routine and the dynamic linkers we care about
9148       // do not support dynamic PREL31 relocations. An REL31 relocation may
9149       // point to a function whose unwinding behaviour is being described but
9150       // we will not mistakenly generate a PLT for that because we should use
9151       // a local section symbol.
9152
9153       // If the symbol is fully resolved, this is just a relative
9154       // local reloc.  Otherwise we need a PLT entry.
9155       if (gsym->final_value_is_known())
9156         break;
9157       // If building a shared library, we can also skip the PLT entry
9158       // if the symbol is defined in the output file and is protected
9159       // or hidden.
9160       if (gsym->is_defined()
9161           && !gsym->is_from_dynobj()
9162           && !gsym->is_preemptible())
9163         break;
9164       target->make_plt_entry(symtab, layout, gsym);
9165       break;
9166
9167     case elfcpp::R_ARM_GOT_BREL:
9168     case elfcpp::R_ARM_GOT_ABS:
9169     case elfcpp::R_ARM_GOT_PREL:
9170       {
9171         // The symbol requires a GOT entry.
9172         Arm_output_data_got<big_endian>* got =
9173           target->got_section(symtab, layout);
9174         if (gsym->final_value_is_known())
9175           {
9176             // For a STT_GNU_IFUNC symbol we want the PLT address.
9177             if (gsym->type() == elfcpp::STT_GNU_IFUNC)
9178               got->add_global_plt(gsym, GOT_TYPE_STANDARD);
9179             else
9180               got->add_global(gsym, GOT_TYPE_STANDARD);
9181           }
9182         else
9183           {
9184             // If this symbol is not fully resolved, we need to add a
9185             // GOT entry with a dynamic relocation.
9186             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
9187             if (gsym->is_from_dynobj()
9188                 || gsym->is_undefined()
9189                 || gsym->is_preemptible()
9190                 || (gsym->visibility() == elfcpp::STV_PROTECTED
9191                     && parameters->options().shared())
9192                 || (gsym->type() == elfcpp::STT_GNU_IFUNC
9193                     && parameters->options().output_is_position_independent()))
9194               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
9195                                        rel_dyn, elfcpp::R_ARM_GLOB_DAT);
9196             else
9197               {
9198                 // For a STT_GNU_IFUNC symbol we want to write the PLT
9199                 // offset into the GOT, so that function pointer
9200                 // comparisons work correctly.
9201                 bool is_new;
9202                 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
9203                   is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
9204                 else
9205                   {
9206                     is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
9207                     // Tell the dynamic linker to use the PLT address
9208                     // when resolving relocations.
9209                     if (gsym->is_from_dynobj()
9210                         && !parameters->options().shared())
9211                       gsym->set_needs_dynsym_value();
9212                   }
9213                 if (is_new)
9214                   rel_dyn->add_global_relative(
9215                       gsym, elfcpp::R_ARM_RELATIVE, got,
9216                       gsym->got_offset(GOT_TYPE_STANDARD));
9217               }
9218           }
9219       }
9220       break;
9221
9222     case elfcpp::R_ARM_TARGET1:
9223     case elfcpp::R_ARM_TARGET2:
9224       // These should have been mapped to other types already.
9225       // Fall through.
9226     case elfcpp::R_ARM_COPY:
9227     case elfcpp::R_ARM_GLOB_DAT:
9228     case elfcpp::R_ARM_JUMP_SLOT:
9229     case elfcpp::R_ARM_RELATIVE:
9230       // These are relocations which should only be seen by the
9231       // dynamic linker, and should never be seen here.
9232       gold_error(_("%s: unexpected reloc %u in object file"),
9233                  object->name().c_str(), r_type);
9234       break;
9235
9236       // These are initial tls relocs, which are expected when
9237       // linking.
9238     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9239     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9240     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9241     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9242     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9243       {
9244         const bool is_final = gsym->final_value_is_known();
9245         const tls::Tls_optimization optimized_type
9246             = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9247         switch (r_type)
9248           {
9249           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
9250             if (optimized_type == tls::TLSOPT_NONE)
9251               {
9252                 // Create a pair of GOT entries for the module index and
9253                 // dtv-relative offset.
9254                 Arm_output_data_got<big_endian>* got
9255                     = target->got_section(symtab, layout);
9256                 if (!parameters->doing_static_link())
9257                   got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
9258                                                 target->rel_dyn_section(layout),
9259                                                 elfcpp::R_ARM_TLS_DTPMOD32,
9260                                                 elfcpp::R_ARM_TLS_DTPOFF32);
9261                 else
9262                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
9263               }
9264             else
9265               // FIXME: TLS optimization not supported yet.
9266               gold_unreachable();
9267             break;
9268
9269           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
9270             if (optimized_type == tls::TLSOPT_NONE)
9271               {
9272                 // Create a GOT entry for the module index.
9273                 target->got_mod_index_entry(symtab, layout, object);
9274               }
9275             else
9276               // FIXME: TLS optimization not supported yet.
9277               gold_unreachable();
9278             break;
9279
9280           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
9281             break;
9282
9283           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
9284             layout->set_has_static_tls();
9285             if (optimized_type == tls::TLSOPT_NONE)
9286               {
9287                 // Create a GOT entry for the tp-relative offset.
9288                 Arm_output_data_got<big_endian>* got
9289                   = target->got_section(symtab, layout);
9290                 if (!parameters->doing_static_link())
9291                   got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
9292                                            target->rel_dyn_section(layout),
9293                                            elfcpp::R_ARM_TLS_TPOFF32);
9294                 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
9295                   {
9296                     got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
9297                     unsigned int got_offset =
9298                        gsym->got_offset(GOT_TYPE_TLS_OFFSET);
9299                     got->add_static_reloc(got_offset,
9300                                           elfcpp::R_ARM_TLS_TPOFF32, gsym);
9301                   }
9302               }
9303             else
9304               // FIXME: TLS optimization not supported yet.
9305               gold_unreachable();
9306             break;
9307
9308           case elfcpp::R_ARM_TLS_LE32:  // Local-exec
9309             layout->set_has_static_tls();
9310             if (parameters->options().shared())
9311               {
9312                 // We need to create a dynamic relocation.
9313                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
9314                 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
9315                                     output_section, object,
9316                                     data_shndx, reloc.get_r_offset());
9317               }
9318             break;
9319
9320           default:
9321             gold_unreachable();
9322           }
9323       }
9324       break;
9325
9326     case elfcpp::R_ARM_PC24:
9327     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9328     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9329     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9330     default:
9331       unsupported_reloc_global(object, r_type, gsym);
9332       break;
9333     }
9334 }
9335
9336 // Process relocations for gc.
9337
9338 template<bool big_endian>
9339 void
9340 Target_arm<big_endian>::gc_process_relocs(
9341     Symbol_table* symtab,
9342     Layout* layout,
9343     Sized_relobj_file<32, big_endian>* object,
9344     unsigned int data_shndx,
9345     unsigned int,
9346     const unsigned char* prelocs,
9347     size_t reloc_count,
9348     Output_section* output_section,
9349     bool needs_special_offset_handling,
9350     size_t local_symbol_count,
9351     const unsigned char* plocal_symbols)
9352 {
9353   typedef Target_arm<big_endian> Arm;
9354   typedef typename Target_arm<big_endian>::Scan Scan;
9355
9356   gold::gc_process_relocs<32, big_endian, Arm, Scan, Classify_reloc>(
9357     symtab,
9358     layout,
9359     this,
9360     object,
9361     data_shndx,
9362     prelocs,
9363     reloc_count,
9364     output_section,
9365     needs_special_offset_handling,
9366     local_symbol_count,
9367     plocal_symbols);
9368 }
9369
9370 // Scan relocations for a section.
9371
9372 template<bool big_endian>
9373 void
9374 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
9375                                     Layout* layout,
9376                                     Sized_relobj_file<32, big_endian>* object,
9377                                     unsigned int data_shndx,
9378                                     unsigned int sh_type,
9379                                     const unsigned char* prelocs,
9380                                     size_t reloc_count,
9381                                     Output_section* output_section,
9382                                     bool needs_special_offset_handling,
9383                                     size_t local_symbol_count,
9384                                     const unsigned char* plocal_symbols)
9385 {
9386   if (sh_type == elfcpp::SHT_RELA)
9387     {
9388       gold_error(_("%s: unsupported RELA reloc section"),
9389                  object->name().c_str());
9390       return;
9391     }
9392
9393   gold::scan_relocs<32, big_endian, Target_arm, Scan, Classify_reloc>(
9394     symtab,
9395     layout,
9396     this,
9397     object,
9398     data_shndx,
9399     prelocs,
9400     reloc_count,
9401     output_section,
9402     needs_special_offset_handling,
9403     local_symbol_count,
9404     plocal_symbols);
9405 }
9406
9407 // Finalize the sections.
9408
9409 template<bool big_endian>
9410 void
9411 Target_arm<big_endian>::do_finalize_sections(
9412     Layout* layout,
9413     const Input_objects* input_objects,
9414     Symbol_table*)
9415 {
9416   bool merged_any_attributes = false;
9417   // Merge processor-specific flags.
9418   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
9419        p != input_objects->relobj_end();
9420        ++p)
9421     {
9422       Arm_relobj<big_endian>* arm_relobj =
9423         Arm_relobj<big_endian>::as_arm_relobj(*p);
9424       if (arm_relobj->merge_flags_and_attributes())
9425         {
9426           this->merge_processor_specific_flags(
9427               arm_relobj->name(),
9428               arm_relobj->processor_specific_flags());
9429           this->merge_object_attributes(arm_relobj->name().c_str(),
9430                                         arm_relobj->attributes_section_data());
9431           merged_any_attributes = true;
9432         }
9433     }
9434
9435   for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
9436        p != input_objects->dynobj_end();
9437        ++p)
9438     {
9439       Arm_dynobj<big_endian>* arm_dynobj =
9440         Arm_dynobj<big_endian>::as_arm_dynobj(*p);
9441       this->merge_processor_specific_flags(
9442           arm_dynobj->name(),
9443           arm_dynobj->processor_specific_flags());
9444       this->merge_object_attributes(arm_dynobj->name().c_str(),
9445                                     arm_dynobj->attributes_section_data());
9446       merged_any_attributes = true;
9447     }
9448
9449   // Create an empty uninitialized attribute section if we still don't have it
9450   // at this moment.  This happens if there is no attributes sections in all
9451   // inputs.
9452   if (this->attributes_section_data_ == NULL)
9453     this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
9454
9455   const Object_attribute* cpu_arch_attr =
9456     this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
9457   // Check if we need to use Cortex-A8 workaround.
9458   if (parameters->options().user_set_fix_cortex_a8())
9459     this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
9460   else
9461     {
9462       // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
9463       // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
9464       // profile.
9465       const Object_attribute* cpu_arch_profile_attr =
9466         this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
9467       this->fix_cortex_a8_ =
9468         (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
9469          && (cpu_arch_profile_attr->int_value() == 'A'
9470              || cpu_arch_profile_attr->int_value() == 0));
9471     }
9472
9473   // Check if we can use V4BX interworking.
9474   // The V4BX interworking stub contains BX instruction,
9475   // which is not specified for some profiles.
9476   if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
9477       && !this->may_use_v4t_interworking())
9478     gold_error(_("unable to provide V4BX reloc interworking fix up; "
9479                  "the target profile does not support BX instruction"));
9480
9481   // Fill in some more dynamic tags.
9482   const Reloc_section* rel_plt = (this->plt_ == NULL
9483                                   ? NULL
9484                                   : this->plt_->rel_plt());
9485   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
9486                                   this->rel_dyn_, true, false);
9487
9488   // Emit any relocs we saved in an attempt to avoid generating COPY
9489   // relocs.
9490   if (this->copy_relocs_.any_saved_relocs())
9491     this->copy_relocs_.emit(this->rel_dyn_section(layout));
9492
9493   // Handle the .ARM.exidx section.
9494   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
9495
9496   if (!parameters->options().relocatable())
9497     {
9498       if (exidx_section != NULL
9499           && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
9500         {
9501           // For the ARM target, we need to add a PT_ARM_EXIDX segment for
9502           // the .ARM.exidx section.
9503           if (!layout->script_options()->saw_phdrs_clause())
9504             {
9505               gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
9506                                                       0)
9507                           == NULL);
9508               Output_segment*  exidx_segment =
9509                 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
9510               exidx_segment->add_output_section_to_nonload(exidx_section,
9511                                                            elfcpp::PF_R);
9512             }
9513         }
9514     }
9515
9516   // Create an .ARM.attributes section if we have merged any attributes
9517   // from inputs.
9518   if (merged_any_attributes)
9519     {
9520       Output_attributes_section_data* attributes_section =
9521       new Output_attributes_section_data(*this->attributes_section_data_);
9522       layout->add_output_section_data(".ARM.attributes",
9523                                       elfcpp::SHT_ARM_ATTRIBUTES, 0,
9524                                       attributes_section, ORDER_INVALID,
9525                                       false);
9526     }
9527
9528   // Fix up links in section EXIDX headers.
9529   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
9530        p != layout->section_list().end();
9531        ++p)
9532     if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
9533       {
9534         Arm_output_section<big_endian>* os =
9535           Arm_output_section<big_endian>::as_arm_output_section(*p);
9536         os->set_exidx_section_link();
9537       }
9538 }
9539
9540 // Return whether a direct absolute static relocation needs to be applied.
9541 // In cases where Scan::local() or Scan::global() has created
9542 // a dynamic relocation other than R_ARM_RELATIVE, the addend
9543 // of the relocation is carried in the data, and we must not
9544 // apply the static relocation.
9545
9546 template<bool big_endian>
9547 inline bool
9548 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
9549     const Sized_symbol<32>* gsym,
9550     unsigned int r_type,
9551     bool is_32bit,
9552     Output_section* output_section)
9553 {
9554   // If the output section is not allocated, then we didn't call
9555   // scan_relocs, we didn't create a dynamic reloc, and we must apply
9556   // the reloc here.
9557   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
9558       return true;
9559
9560   int ref_flags = Scan::get_reference_flags(r_type);
9561
9562   // For local symbols, we will have created a non-RELATIVE dynamic
9563   // relocation only if (a) the output is position independent,
9564   // (b) the relocation is absolute (not pc- or segment-relative), and
9565   // (c) the relocation is not 32 bits wide.
9566   if (gsym == NULL)
9567     return !(parameters->options().output_is_position_independent()
9568              && (ref_flags & Symbol::ABSOLUTE_REF)
9569              && !is_32bit);
9570
9571   // For global symbols, we use the same helper routines used in the
9572   // scan pass.  If we did not create a dynamic relocation, or if we
9573   // created a RELATIVE dynamic relocation, we should apply the static
9574   // relocation.
9575   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
9576   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
9577                  && gsym->can_use_relative_reloc(ref_flags
9578                                                  & Symbol::FUNCTION_CALL);
9579   return !has_dyn || is_rel;
9580 }
9581
9582 // Perform a relocation.
9583
9584 template<bool big_endian>
9585 inline bool
9586 Target_arm<big_endian>::Relocate::relocate(
9587     const Relocate_info<32, big_endian>* relinfo,
9588     unsigned int,
9589     Target_arm* target,
9590     Output_section* output_section,
9591     size_t relnum,
9592     const unsigned char* preloc,
9593     const Sized_symbol<32>* gsym,
9594     const Symbol_value<32>* psymval,
9595     unsigned char* view,
9596     Arm_address address,
9597     section_size_type view_size)
9598 {
9599   if (view == NULL)
9600     return true;
9601
9602   typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
9603
9604   const elfcpp::Rel<32, big_endian> rel(preloc);
9605   unsigned int r_type = elfcpp::elf_r_type<32>(rel.get_r_info());
9606   r_type = target->get_real_reloc_type(r_type);
9607   const Arm_reloc_property* reloc_property =
9608     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9609   if (reloc_property == NULL)
9610     {
9611       std::string reloc_name =
9612         arm_reloc_property_table->reloc_name_in_error_message(r_type);
9613       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9614                              _("cannot relocate %s in object file"),
9615                              reloc_name.c_str());
9616       return true;
9617     }
9618
9619   const Arm_relobj<big_endian>* object =
9620     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9621
9622   // If the final branch target of a relocation is THUMB instruction, this
9623   // is 1.  Otherwise it is 0.
9624   Arm_address thumb_bit = 0;
9625   Symbol_value<32> symval;
9626   bool is_weakly_undefined_without_plt = false;
9627   bool have_got_offset = false;
9628   unsigned int got_offset = 0;
9629
9630   // If the relocation uses the GOT entry of a symbol instead of the symbol
9631   // itself, we don't care about whether the symbol is defined or what kind
9632   // of symbol it is.
9633   if (reloc_property->uses_got_entry())
9634     {
9635       // Get the GOT offset.
9636       // The GOT pointer points to the end of the GOT section.
9637       // We need to subtract the size of the GOT section to get
9638       // the actual offset to use in the relocation.
9639       // TODO: We should move GOT offset computing code in TLS relocations
9640       // to here.
9641       switch (r_type)
9642         {
9643         case elfcpp::R_ARM_GOT_BREL:
9644         case elfcpp::R_ARM_GOT_PREL:
9645           if (gsym != NULL)
9646             {
9647               gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
9648               got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
9649                             - target->got_size());
9650             }
9651           else
9652             {
9653               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9654               gold_assert(object->local_has_got_offset(r_sym,
9655                                                        GOT_TYPE_STANDARD));
9656               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
9657                             - target->got_size());
9658             }
9659           have_got_offset = true;
9660           break;
9661
9662         default:
9663           break;
9664         }
9665     }
9666   else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
9667     {
9668       if (gsym != NULL)
9669         {
9670           // This is a global symbol.  Determine if we use PLT and if the
9671           // final target is THUMB.
9672           if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
9673             {
9674               // This uses a PLT, change the symbol value.
9675               symval.set_output_value(target->plt_address_for_global(gsym));
9676               psymval = &symval;
9677             }
9678           else if (gsym->is_weak_undefined())
9679             {
9680               // This is a weakly undefined symbol and we do not use PLT
9681               // for this relocation.  A branch targeting this symbol will
9682               // be converted into an NOP.
9683               is_weakly_undefined_without_plt = true;
9684             }
9685           else if (gsym->is_undefined() && reloc_property->uses_symbol())
9686             {
9687               // This relocation uses the symbol value but the symbol is
9688               // undefined.  Exit early and have the caller reporting an
9689               // error.
9690               return true;
9691             }
9692           else
9693             {
9694               // Set thumb bit if symbol:
9695               // -Has type STT_ARM_TFUNC or
9696               // -Has type STT_FUNC, is defined and with LSB in value set.
9697               thumb_bit =
9698                 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
9699                  || (gsym->type() == elfcpp::STT_FUNC
9700                      && !gsym->is_undefined()
9701                      && ((psymval->value(object, 0) & 1) != 0)))
9702                 ? 1
9703                 : 0);
9704             }
9705         }
9706       else
9707         {
9708           // This is a local symbol.  Determine if the final target is THUMB.
9709           // We saved this information when all the local symbols were read.
9710           elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
9711           unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9712           thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9713
9714           if (psymval->is_ifunc_symbol() && object->local_has_plt_offset(r_sym))
9715             {
9716               symval.set_output_value(
9717                   target->plt_address_for_local(object, r_sym));
9718               psymval = &symval;
9719             }
9720         }
9721     }
9722   else
9723     {
9724       // This is a fake relocation synthesized for a stub.  It does not have
9725       // a real symbol.  We just look at the LSB of the symbol value to
9726       // determine if the target is THUMB or not.
9727       thumb_bit = ((psymval->value(object, 0) & 1) != 0);
9728     }
9729
9730   // Strip LSB if this points to a THUMB target.
9731   if (thumb_bit != 0
9732       && reloc_property->uses_thumb_bit()
9733       && ((psymval->value(object, 0) & 1) != 0))
9734     {
9735       Arm_address stripped_value =
9736         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9737       symval.set_output_value(stripped_value);
9738       psymval = &symval;
9739     }
9740
9741   // To look up relocation stubs, we need to pass the symbol table index of
9742   // a local symbol.
9743   unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9744
9745   // Get the addressing origin of the output segment defining the
9746   // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
9747   Arm_address sym_origin = 0;
9748   if (reloc_property->uses_symbol_base())
9749     {
9750       if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
9751         // R_ARM_BASE_ABS with the NULL symbol will give the
9752         // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
9753         // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
9754         sym_origin = target->got_plt_section()->address();
9755       else if (gsym == NULL)
9756         sym_origin = 0;
9757       else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
9758         sym_origin = gsym->output_segment()->vaddr();
9759       else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
9760         sym_origin = gsym->output_data()->address();
9761
9762       // TODO: Assumes the segment base to be zero for the global symbols
9763       // till the proper support for the segment-base-relative addressing
9764       // will be implemented.  This is consistent with GNU ld.
9765     }
9766
9767   // For relative addressing relocation, find out the relative address base.
9768   Arm_address relative_address_base = 0;
9769   switch(reloc_property->relative_address_base())
9770     {
9771     case Arm_reloc_property::RAB_NONE:
9772     // Relocations with relative address bases RAB_TLS and RAB_tp are
9773     // handled by relocate_tls.  So we do not need to do anything here.
9774     case Arm_reloc_property::RAB_TLS:
9775     case Arm_reloc_property::RAB_tp:
9776       break;
9777     case Arm_reloc_property::RAB_B_S:
9778       relative_address_base = sym_origin;
9779       break;
9780     case Arm_reloc_property::RAB_GOT_ORG:
9781       relative_address_base = target->got_plt_section()->address();
9782       break;
9783     case Arm_reloc_property::RAB_P:
9784       relative_address_base = address;
9785       break;
9786     case Arm_reloc_property::RAB_Pa:
9787       relative_address_base = address & 0xfffffffcU;
9788       break;
9789     default:
9790       gold_unreachable();
9791     }
9792
9793   typename Arm_relocate_functions::Status reloc_status =
9794         Arm_relocate_functions::STATUS_OKAY;
9795   bool check_overflow = reloc_property->checks_overflow();
9796   switch (r_type)
9797     {
9798     case elfcpp::R_ARM_NONE:
9799       break;
9800
9801     case elfcpp::R_ARM_ABS8:
9802       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9803         reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
9804       break;
9805
9806     case elfcpp::R_ARM_ABS12:
9807       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9808         reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
9809       break;
9810
9811     case elfcpp::R_ARM_ABS16:
9812       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9813         reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
9814       break;
9815
9816     case elfcpp::R_ARM_ABS32:
9817       if (should_apply_static_reloc(gsym, r_type, true, output_section))
9818         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9819                                                      thumb_bit);
9820       break;
9821
9822     case elfcpp::R_ARM_ABS32_NOI:
9823       if (should_apply_static_reloc(gsym, r_type, true, output_section))
9824         // No thumb bit for this relocation: (S + A)
9825         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9826                                                      0);
9827       break;
9828
9829     case elfcpp::R_ARM_MOVW_ABS_NC:
9830       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9831         reloc_status = Arm_relocate_functions::movw(view, object, psymval,
9832                                                     0, thumb_bit,
9833                                                     check_overflow);
9834       break;
9835
9836     case elfcpp::R_ARM_MOVT_ABS:
9837       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9838         reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
9839       break;
9840
9841     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9842       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9843         reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
9844                                                         0, thumb_bit, false);
9845       break;
9846
9847     case elfcpp::R_ARM_THM_MOVT_ABS:
9848       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9849         reloc_status = Arm_relocate_functions::thm_movt(view, object,
9850                                                         psymval, 0);
9851       break;
9852
9853     case elfcpp::R_ARM_MOVW_PREL_NC:
9854     case elfcpp::R_ARM_MOVW_BREL_NC:
9855     case elfcpp::R_ARM_MOVW_BREL:
9856       reloc_status =
9857         Arm_relocate_functions::movw(view, object, psymval,
9858                                      relative_address_base, thumb_bit,
9859                                      check_overflow);
9860       break;
9861
9862     case elfcpp::R_ARM_MOVT_PREL:
9863     case elfcpp::R_ARM_MOVT_BREL:
9864       reloc_status =
9865         Arm_relocate_functions::movt(view, object, psymval,
9866                                      relative_address_base);
9867       break;
9868
9869     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9870     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9871     case elfcpp::R_ARM_THM_MOVW_BREL:
9872       reloc_status =
9873         Arm_relocate_functions::thm_movw(view, object, psymval,
9874                                          relative_address_base,
9875                                          thumb_bit, check_overflow);
9876       break;
9877
9878     case elfcpp::R_ARM_THM_MOVT_PREL:
9879     case elfcpp::R_ARM_THM_MOVT_BREL:
9880       reloc_status =
9881         Arm_relocate_functions::thm_movt(view, object, psymval,
9882                                          relative_address_base);
9883       break;
9884
9885     case elfcpp::R_ARM_REL32:
9886       reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9887                                                    address, thumb_bit);
9888       break;
9889
9890     case elfcpp::R_ARM_THM_ABS5:
9891       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9892         reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
9893       break;
9894
9895     // Thumb long branches.
9896     case elfcpp::R_ARM_THM_CALL:
9897     case elfcpp::R_ARM_THM_XPC22:
9898     case elfcpp::R_ARM_THM_JUMP24:
9899       reloc_status =
9900         Arm_relocate_functions::thumb_branch_common(
9901             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9902             thumb_bit, is_weakly_undefined_without_plt);
9903       break;
9904
9905     case elfcpp::R_ARM_GOTOFF32:
9906       {
9907         Arm_address got_origin;
9908         got_origin = target->got_plt_section()->address();
9909         reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9910                                                      got_origin, thumb_bit);
9911       }
9912       break;
9913
9914     case elfcpp::R_ARM_BASE_PREL:
9915       gold_assert(gsym != NULL);
9916       reloc_status =
9917           Arm_relocate_functions::base_prel(view, sym_origin, address);
9918       break;
9919
9920     case elfcpp::R_ARM_BASE_ABS:
9921       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9922         reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
9923       break;
9924
9925     case elfcpp::R_ARM_GOT_BREL:
9926       gold_assert(have_got_offset);
9927       reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
9928       break;
9929
9930     case elfcpp::R_ARM_GOT_PREL:
9931       gold_assert(have_got_offset);
9932       // Get the address origin for GOT PLT, which is allocated right
9933       // after the GOT section, to calculate an absolute address of
9934       // the symbol GOT entry (got_origin + got_offset).
9935       Arm_address got_origin;
9936       got_origin = target->got_plt_section()->address();
9937       reloc_status = Arm_relocate_functions::got_prel(view,
9938                                                       got_origin + got_offset,
9939                                                       address);
9940       break;
9941
9942     case elfcpp::R_ARM_PLT32:
9943     case elfcpp::R_ARM_CALL:
9944     case elfcpp::R_ARM_JUMP24:
9945     case elfcpp::R_ARM_XPC25:
9946       gold_assert(gsym == NULL
9947                   || gsym->has_plt_offset()
9948                   || gsym->final_value_is_known()
9949                   || (gsym->is_defined()
9950                       && !gsym->is_from_dynobj()
9951                       && !gsym->is_preemptible()));
9952       reloc_status =
9953         Arm_relocate_functions::arm_branch_common(
9954             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9955             thumb_bit, is_weakly_undefined_without_plt);
9956       break;
9957
9958     case elfcpp::R_ARM_THM_JUMP19:
9959       reloc_status =
9960         Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9961                                            thumb_bit);
9962       break;
9963
9964     case elfcpp::R_ARM_THM_JUMP6:
9965       reloc_status =
9966         Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9967       break;
9968
9969     case elfcpp::R_ARM_THM_JUMP8:
9970       reloc_status =
9971         Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9972       break;
9973
9974     case elfcpp::R_ARM_THM_JUMP11:
9975       reloc_status =
9976         Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9977       break;
9978
9979     case elfcpp::R_ARM_PREL31:
9980       reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9981                                                     address, thumb_bit);
9982       break;
9983
9984     case elfcpp::R_ARM_V4BX:
9985       if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9986         {
9987           const bool is_v4bx_interworking =
9988               (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9989           reloc_status =
9990             Arm_relocate_functions::v4bx(relinfo, view, object, address,
9991                                          is_v4bx_interworking);
9992         }
9993       break;
9994
9995     case elfcpp::R_ARM_THM_PC8:
9996       reloc_status =
9997         Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9998       break;
9999
10000     case elfcpp::R_ARM_THM_PC12:
10001       reloc_status =
10002         Arm_relocate_functions::thm_pc12(view, object, psymval, address);
10003       break;
10004
10005     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
10006       reloc_status =
10007         Arm_relocate_functions::thm_alu11(view, object, psymval, address,
10008                                           thumb_bit);
10009       break;
10010
10011     case elfcpp::R_ARM_ALU_PC_G0_NC:
10012     case elfcpp::R_ARM_ALU_PC_G0:
10013     case elfcpp::R_ARM_ALU_PC_G1_NC:
10014     case elfcpp::R_ARM_ALU_PC_G1:
10015     case elfcpp::R_ARM_ALU_PC_G2:
10016     case elfcpp::R_ARM_ALU_SB_G0_NC:
10017     case elfcpp::R_ARM_ALU_SB_G0:
10018     case elfcpp::R_ARM_ALU_SB_G1_NC:
10019     case elfcpp::R_ARM_ALU_SB_G1:
10020     case elfcpp::R_ARM_ALU_SB_G2:
10021       reloc_status =
10022         Arm_relocate_functions::arm_grp_alu(view, object, psymval,
10023                                             reloc_property->group_index(),
10024                                             relative_address_base,
10025                                             thumb_bit, check_overflow);
10026       break;
10027
10028     case elfcpp::R_ARM_LDR_PC_G0:
10029     case elfcpp::R_ARM_LDR_PC_G1:
10030     case elfcpp::R_ARM_LDR_PC_G2:
10031     case elfcpp::R_ARM_LDR_SB_G0:
10032     case elfcpp::R_ARM_LDR_SB_G1:
10033     case elfcpp::R_ARM_LDR_SB_G2:
10034       reloc_status =
10035           Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
10036                                               reloc_property->group_index(),
10037                                               relative_address_base);
10038       break;
10039
10040     case elfcpp::R_ARM_LDRS_PC_G0:
10041     case elfcpp::R_ARM_LDRS_PC_G1:
10042     case elfcpp::R_ARM_LDRS_PC_G2:
10043     case elfcpp::R_ARM_LDRS_SB_G0:
10044     case elfcpp::R_ARM_LDRS_SB_G1:
10045     case elfcpp::R_ARM_LDRS_SB_G2:
10046       reloc_status =
10047           Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
10048                                                reloc_property->group_index(),
10049                                                relative_address_base);
10050       break;
10051
10052     case elfcpp::R_ARM_LDC_PC_G0:
10053     case elfcpp::R_ARM_LDC_PC_G1:
10054     case elfcpp::R_ARM_LDC_PC_G2:
10055     case elfcpp::R_ARM_LDC_SB_G0:
10056     case elfcpp::R_ARM_LDC_SB_G1:
10057     case elfcpp::R_ARM_LDC_SB_G2:
10058       reloc_status =
10059           Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
10060                                               reloc_property->group_index(),
10061                                               relative_address_base);
10062       break;
10063
10064       // These are initial tls relocs, which are expected when
10065       // linking.
10066     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
10067     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
10068     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
10069     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
10070     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
10071       reloc_status =
10072         this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
10073                            view, address, view_size);
10074       break;
10075
10076     // The known and unknown unsupported and/or deprecated relocations.
10077     case elfcpp::R_ARM_PC24:
10078     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
10079     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
10080     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
10081     default:
10082       // Just silently leave the method. We should get an appropriate error
10083       // message in the scan methods.
10084       break;
10085     }
10086
10087   // Report any errors.
10088   switch (reloc_status)
10089     {
10090     case Arm_relocate_functions::STATUS_OKAY:
10091       break;
10092     case Arm_relocate_functions::STATUS_OVERFLOW:
10093       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
10094                              _("relocation overflow in %s"),
10095                              reloc_property->name().c_str());
10096       break;
10097     case Arm_relocate_functions::STATUS_BAD_RELOC:
10098       gold_error_at_location(
10099         relinfo,
10100         relnum,
10101         rel.get_r_offset(),
10102         _("unexpected opcode while processing relocation %s"),
10103         reloc_property->name().c_str());
10104       break;
10105     default:
10106       gold_unreachable();
10107     }
10108
10109   return true;
10110 }
10111
10112 // Perform a TLS relocation.
10113
10114 template<bool big_endian>
10115 inline typename Arm_relocate_functions<big_endian>::Status
10116 Target_arm<big_endian>::Relocate::relocate_tls(
10117     const Relocate_info<32, big_endian>* relinfo,
10118     Target_arm<big_endian>* target,
10119     size_t relnum,
10120     const elfcpp::Rel<32, big_endian>& rel,
10121     unsigned int r_type,
10122     const Sized_symbol<32>* gsym,
10123     const Symbol_value<32>* psymval,
10124     unsigned char* view,
10125     elfcpp::Elf_types<32>::Elf_Addr address,
10126     section_size_type /*view_size*/ )
10127 {
10128   typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
10129   typedef Relocate_functions<32, big_endian> RelocFuncs;
10130   Output_segment* tls_segment = relinfo->layout->tls_segment();
10131
10132   const Sized_relobj_file<32, big_endian>* object = relinfo->object;
10133
10134   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
10135
10136   const bool is_final = (gsym == NULL
10137                          ? !parameters->options().shared()
10138                          : gsym->final_value_is_known());
10139   const tls::Tls_optimization optimized_type
10140       = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
10141   switch (r_type)
10142     {
10143     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
10144         {
10145           unsigned int got_type = GOT_TYPE_TLS_PAIR;
10146           unsigned int got_offset;
10147           if (gsym != NULL)
10148             {
10149               gold_assert(gsym->has_got_offset(got_type));
10150               got_offset = gsym->got_offset(got_type) - target->got_size();
10151             }
10152           else
10153             {
10154               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
10155               gold_assert(object->local_has_got_offset(r_sym, got_type));
10156               got_offset = (object->local_got_offset(r_sym, got_type)
10157                             - target->got_size());
10158             }
10159           if (optimized_type == tls::TLSOPT_NONE)
10160             {
10161               Arm_address got_entry =
10162                 target->got_plt_section()->address() + got_offset;
10163
10164               // Relocate the field with the PC relative offset of the pair of
10165               // GOT entries.
10166               RelocFuncs::pcrel32_unaligned(view, got_entry, address);
10167               return ArmRelocFuncs::STATUS_OKAY;
10168             }
10169         }
10170       break;
10171
10172     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
10173       if (optimized_type == tls::TLSOPT_NONE)
10174         {
10175           // Relocate the field with the offset of the GOT entry for
10176           // the module index.
10177           unsigned int got_offset;
10178           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
10179                         - target->got_size());
10180           Arm_address got_entry =
10181             target->got_plt_section()->address() + got_offset;
10182
10183           // Relocate the field with the PC relative offset of the pair of
10184           // GOT entries.
10185           RelocFuncs::pcrel32_unaligned(view, got_entry, address);
10186           return ArmRelocFuncs::STATUS_OKAY;
10187         }
10188       break;
10189
10190     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
10191       RelocFuncs::rel32_unaligned(view, value);
10192       return ArmRelocFuncs::STATUS_OKAY;
10193
10194     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
10195       if (optimized_type == tls::TLSOPT_NONE)
10196         {
10197           // Relocate the field with the offset of the GOT entry for
10198           // the tp-relative offset of the symbol.
10199           unsigned int got_type = GOT_TYPE_TLS_OFFSET;
10200           unsigned int got_offset;
10201           if (gsym != NULL)
10202             {
10203               gold_assert(gsym->has_got_offset(got_type));
10204               got_offset = gsym->got_offset(got_type);
10205             }
10206           else
10207             {
10208               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
10209               gold_assert(object->local_has_got_offset(r_sym, got_type));
10210               got_offset = object->local_got_offset(r_sym, got_type);
10211             }
10212
10213           // All GOT offsets are relative to the end of the GOT.
10214           got_offset -= target->got_size();
10215
10216           Arm_address got_entry =
10217             target->got_plt_section()->address() + got_offset;
10218
10219           // Relocate the field with the PC relative offset of the GOT entry.
10220           RelocFuncs::pcrel32_unaligned(view, got_entry, address);
10221           return ArmRelocFuncs::STATUS_OKAY;
10222         }
10223       break;
10224
10225     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
10226       // If we're creating a shared library, a dynamic relocation will
10227       // have been created for this location, so do not apply it now.
10228       if (!parameters->options().shared())
10229         {
10230           gold_assert(tls_segment != NULL);
10231
10232           // $tp points to the TCB, which is followed by the TLS, so we
10233           // need to add TCB size to the offset.
10234           Arm_address aligned_tcb_size =
10235             align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
10236           RelocFuncs::rel32_unaligned(view, value + aligned_tcb_size);
10237
10238         }
10239       return ArmRelocFuncs::STATUS_OKAY;
10240
10241     default:
10242       gold_unreachable();
10243     }
10244
10245   gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
10246                          _("unsupported reloc %u"),
10247                          r_type);
10248   return ArmRelocFuncs::STATUS_BAD_RELOC;
10249 }
10250
10251 // Relocate section data.
10252
10253 template<bool big_endian>
10254 void
10255 Target_arm<big_endian>::relocate_section(
10256     const Relocate_info<32, big_endian>* relinfo,
10257     unsigned int sh_type,
10258     const unsigned char* prelocs,
10259     size_t reloc_count,
10260     Output_section* output_section,
10261     bool needs_special_offset_handling,
10262     unsigned char* view,
10263     Arm_address address,
10264     section_size_type view_size,
10265     const Reloc_symbol_changes* reloc_symbol_changes)
10266 {
10267   typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
10268   gold_assert(sh_type == elfcpp::SHT_REL);
10269
10270   // See if we are relocating a relaxed input section.  If so, the view
10271   // covers the whole output section and we need to adjust accordingly.
10272   if (needs_special_offset_handling)
10273     {
10274       const Output_relaxed_input_section* poris =
10275         output_section->find_relaxed_input_section(relinfo->object,
10276                                                    relinfo->data_shndx);
10277       if (poris != NULL)
10278         {
10279           Arm_address section_address = poris->address();
10280           section_size_type section_size = poris->data_size();
10281
10282           gold_assert((section_address >= address)
10283                       && ((section_address + section_size)
10284                           <= (address + view_size)));
10285
10286           off_t offset = section_address - address;
10287           view += offset;
10288           address += offset;
10289           view_size = section_size;
10290         }
10291     }
10292
10293   gold::relocate_section<32, big_endian, Target_arm, Arm_relocate,
10294                          gold::Default_comdat_behavior, Classify_reloc>(
10295     relinfo,
10296     this,
10297     prelocs,
10298     reloc_count,
10299     output_section,
10300     needs_special_offset_handling,
10301     view,
10302     address,
10303     view_size,
10304     reloc_symbol_changes);
10305 }
10306
10307 // Return the size of a relocation while scanning during a relocatable
10308 // link.
10309
10310 template<bool big_endian>
10311 unsigned int
10312 Target_arm<big_endian>::Classify_reloc::get_size_for_reloc(
10313     unsigned int r_type,
10314     Relobj* object)
10315 {
10316   Target_arm<big_endian>* arm_target =
10317       Target_arm<big_endian>::default_target();
10318   r_type = arm_target->get_real_reloc_type(r_type);
10319   const Arm_reloc_property* arp =
10320       arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10321   if (arp != NULL)
10322     return arp->size();
10323   else
10324     {
10325       std::string reloc_name =
10326         arm_reloc_property_table->reloc_name_in_error_message(r_type);
10327       gold_error(_("%s: unexpected %s in object file"),
10328                  object->name().c_str(), reloc_name.c_str());
10329       return 0;
10330     }
10331 }
10332
10333 // Scan the relocs during a relocatable link.
10334
10335 template<bool big_endian>
10336 void
10337 Target_arm<big_endian>::scan_relocatable_relocs(
10338     Symbol_table* symtab,
10339     Layout* layout,
10340     Sized_relobj_file<32, big_endian>* object,
10341     unsigned int data_shndx,
10342     unsigned int sh_type,
10343     const unsigned char* prelocs,
10344     size_t reloc_count,
10345     Output_section* output_section,
10346     bool needs_special_offset_handling,
10347     size_t local_symbol_count,
10348     const unsigned char* plocal_symbols,
10349     Relocatable_relocs* rr)
10350 {
10351   typedef Arm_scan_relocatable_relocs<big_endian, Classify_reloc>
10352       Scan_relocatable_relocs;
10353
10354   gold_assert(sh_type == elfcpp::SHT_REL);
10355
10356   gold::scan_relocatable_relocs<32, big_endian, Scan_relocatable_relocs>(
10357     symtab,
10358     layout,
10359     object,
10360     data_shndx,
10361     prelocs,
10362     reloc_count,
10363     output_section,
10364     needs_special_offset_handling,
10365     local_symbol_count,
10366     plocal_symbols,
10367     rr);
10368 }
10369
10370 // Scan the relocs for --emit-relocs.
10371
10372 template<bool big_endian>
10373 void
10374 Target_arm<big_endian>::emit_relocs_scan(Symbol_table* symtab,
10375     Layout* layout,
10376     Sized_relobj_file<32, big_endian>* object,
10377     unsigned int data_shndx,
10378     unsigned int sh_type,
10379     const unsigned char* prelocs,
10380     size_t reloc_count,
10381     Output_section* output_section,
10382     bool needs_special_offset_handling,
10383     size_t local_symbol_count,
10384     const unsigned char* plocal_syms,
10385     Relocatable_relocs* rr)
10386 {
10387   typedef gold::Default_classify_reloc<elfcpp::SHT_REL, 32, big_endian>
10388       Classify_reloc;
10389   typedef gold::Default_emit_relocs_strategy<Classify_reloc>
10390       Emit_relocs_strategy;
10391
10392   gold_assert(sh_type == elfcpp::SHT_REL);
10393
10394   gold::scan_relocatable_relocs<32, big_endian, Emit_relocs_strategy>(
10395     symtab,
10396     layout,
10397     object,
10398     data_shndx,
10399     prelocs,
10400     reloc_count,
10401     output_section,
10402     needs_special_offset_handling,
10403     local_symbol_count,
10404     plocal_syms,
10405     rr);
10406 }
10407
10408 // Emit relocations for a section.
10409
10410 template<bool big_endian>
10411 void
10412 Target_arm<big_endian>::relocate_relocs(
10413     const Relocate_info<32, big_endian>* relinfo,
10414     unsigned int sh_type,
10415     const unsigned char* prelocs,
10416     size_t reloc_count,
10417     Output_section* output_section,
10418     typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
10419     unsigned char* view,
10420     Arm_address view_address,
10421     section_size_type view_size,
10422     unsigned char* reloc_view,
10423     section_size_type reloc_view_size)
10424 {
10425   gold_assert(sh_type == elfcpp::SHT_REL);
10426
10427   gold::relocate_relocs<32, big_endian, Classify_reloc>(
10428     relinfo,
10429     prelocs,
10430     reloc_count,
10431     output_section,
10432     offset_in_output_section,
10433     view,
10434     view_address,
10435     view_size,
10436     reloc_view,
10437     reloc_view_size);
10438 }
10439
10440 // Perform target-specific processing in a relocatable link.  This is
10441 // only used if we use the relocation strategy RELOC_SPECIAL.
10442
10443 template<bool big_endian>
10444 void
10445 Target_arm<big_endian>::relocate_special_relocatable(
10446     const Relocate_info<32, big_endian>* relinfo,
10447     unsigned int sh_type,
10448     const unsigned char* preloc_in,
10449     size_t relnum,
10450     Output_section* output_section,
10451     typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
10452     unsigned char* view,
10453     elfcpp::Elf_types<32>::Elf_Addr view_address,
10454     section_size_type,
10455     unsigned char* preloc_out)
10456 {
10457   // We can only handle REL type relocation sections.
10458   gold_assert(sh_type == elfcpp::SHT_REL);
10459
10460   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
10461   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
10462     Reltype_write;
10463   const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
10464
10465   const Arm_relobj<big_endian>* object =
10466     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10467   const unsigned int local_count = object->local_symbol_count();
10468
10469   Reltype reloc(preloc_in);
10470   Reltype_write reloc_write(preloc_out);
10471
10472   elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
10473   const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
10474   const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
10475
10476   const Arm_reloc_property* arp =
10477     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10478   gold_assert(arp != NULL);
10479
10480   // Get the new symbol index.
10481   // We only use RELOC_SPECIAL strategy in local relocations.
10482   gold_assert(r_sym < local_count);
10483
10484   // We are adjusting a section symbol.  We need to find
10485   // the symbol table index of the section symbol for
10486   // the output section corresponding to input section
10487   // in which this symbol is defined.
10488   bool is_ordinary;
10489   unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
10490   gold_assert(is_ordinary);
10491   Output_section* os = object->output_section(shndx);
10492   gold_assert(os != NULL);
10493   gold_assert(os->needs_symtab_index());
10494   unsigned int new_symndx = os->symtab_index();
10495
10496   // Get the new offset--the location in the output section where
10497   // this relocation should be applied.
10498
10499   Arm_address offset = reloc.get_r_offset();
10500   Arm_address new_offset;
10501   if (offset_in_output_section != invalid_address)
10502     new_offset = offset + offset_in_output_section;
10503   else
10504     {
10505       section_offset_type sot_offset =
10506           convert_types<section_offset_type, Arm_address>(offset);
10507       section_offset_type new_sot_offset =
10508           output_section->output_offset(object, relinfo->data_shndx,
10509                                         sot_offset);
10510       gold_assert(new_sot_offset != -1);
10511       new_offset = new_sot_offset;
10512     }
10513
10514   // In an object file, r_offset is an offset within the section.
10515   // In an executable or dynamic object, generated by
10516   // --emit-relocs, r_offset is an absolute address.
10517   if (!parameters->options().relocatable())
10518     {
10519       new_offset += view_address;
10520       if (offset_in_output_section != invalid_address)
10521         new_offset -= offset_in_output_section;
10522     }
10523
10524   reloc_write.put_r_offset(new_offset);
10525   reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
10526
10527   // Handle the reloc addend.
10528   // The relocation uses a section symbol in the input file.
10529   // We are adjusting it to use a section symbol in the output
10530   // file.  The input section symbol refers to some address in
10531   // the input section.  We need the relocation in the output
10532   // file to refer to that same address.  This adjustment to
10533   // the addend is the same calculation we use for a simple
10534   // absolute relocation for the input section symbol.
10535
10536   const Symbol_value<32>* psymval = object->local_symbol(r_sym);
10537
10538   // Handle THUMB bit.
10539   Symbol_value<32> symval;
10540   Arm_address thumb_bit =
10541      object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
10542   if (thumb_bit != 0
10543       && arp->uses_thumb_bit()
10544       && ((psymval->value(object, 0) & 1) != 0))
10545     {
10546       Arm_address stripped_value =
10547         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
10548       symval.set_output_value(stripped_value);
10549       psymval = &symval;
10550     }
10551
10552   unsigned char* paddend = view + offset;
10553   typename Arm_relocate_functions<big_endian>::Status reloc_status =
10554         Arm_relocate_functions<big_endian>::STATUS_OKAY;
10555   switch (r_type)
10556     {
10557     case elfcpp::R_ARM_ABS8:
10558       reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
10559                                                               psymval);
10560       break;
10561
10562     case elfcpp::R_ARM_ABS12:
10563       reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
10564                                                                psymval);
10565       break;
10566
10567     case elfcpp::R_ARM_ABS16:
10568       reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
10569                                                                psymval);
10570       break;
10571
10572     case elfcpp::R_ARM_THM_ABS5:
10573       reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
10574                                                                   object,
10575                                                                   psymval);
10576       break;
10577
10578     case elfcpp::R_ARM_MOVW_ABS_NC:
10579     case elfcpp::R_ARM_MOVW_PREL_NC:
10580     case elfcpp::R_ARM_MOVW_BREL_NC:
10581     case elfcpp::R_ARM_MOVW_BREL:
10582       reloc_status = Arm_relocate_functions<big_endian>::movw(
10583           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
10584       break;
10585
10586     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
10587     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
10588     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
10589     case elfcpp::R_ARM_THM_MOVW_BREL:
10590       reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
10591           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
10592       break;
10593
10594     case elfcpp::R_ARM_THM_CALL:
10595     case elfcpp::R_ARM_THM_XPC22:
10596     case elfcpp::R_ARM_THM_JUMP24:
10597       reloc_status =
10598         Arm_relocate_functions<big_endian>::thumb_branch_common(
10599             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
10600             false);
10601       break;
10602
10603     case elfcpp::R_ARM_PLT32:
10604     case elfcpp::R_ARM_CALL:
10605     case elfcpp::R_ARM_JUMP24:
10606     case elfcpp::R_ARM_XPC25:
10607       reloc_status =
10608         Arm_relocate_functions<big_endian>::arm_branch_common(
10609             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
10610             false);
10611       break;
10612
10613     case elfcpp::R_ARM_THM_JUMP19:
10614       reloc_status =
10615         Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
10616                                                        psymval, 0, thumb_bit);
10617       break;
10618
10619     case elfcpp::R_ARM_THM_JUMP6:
10620       reloc_status =
10621         Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
10622                                                       0);
10623       break;
10624
10625     case elfcpp::R_ARM_THM_JUMP8:
10626       reloc_status =
10627         Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
10628                                                       0);
10629       break;
10630
10631     case elfcpp::R_ARM_THM_JUMP11:
10632       reloc_status =
10633         Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
10634                                                        0);
10635       break;
10636
10637     case elfcpp::R_ARM_PREL31:
10638       reloc_status =
10639         Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
10640                                                    thumb_bit);
10641       break;
10642
10643     case elfcpp::R_ARM_THM_PC8:
10644       reloc_status =
10645         Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
10646                                                     0);
10647       break;
10648
10649     case elfcpp::R_ARM_THM_PC12:
10650       reloc_status =
10651         Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
10652                                                      0);
10653       break;
10654
10655     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
10656       reloc_status =
10657         Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
10658                                                       0, thumb_bit);
10659       break;
10660
10661     // These relocation truncate relocation results so we cannot handle them
10662     // in a relocatable link.
10663     case elfcpp::R_ARM_MOVT_ABS:
10664     case elfcpp::R_ARM_THM_MOVT_ABS:
10665     case elfcpp::R_ARM_MOVT_PREL:
10666     case elfcpp::R_ARM_MOVT_BREL:
10667     case elfcpp::R_ARM_THM_MOVT_PREL:
10668     case elfcpp::R_ARM_THM_MOVT_BREL:
10669     case elfcpp::R_ARM_ALU_PC_G0_NC:
10670     case elfcpp::R_ARM_ALU_PC_G0:
10671     case elfcpp::R_ARM_ALU_PC_G1_NC:
10672     case elfcpp::R_ARM_ALU_PC_G1:
10673     case elfcpp::R_ARM_ALU_PC_G2:
10674     case elfcpp::R_ARM_ALU_SB_G0_NC:
10675     case elfcpp::R_ARM_ALU_SB_G0:
10676     case elfcpp::R_ARM_ALU_SB_G1_NC:
10677     case elfcpp::R_ARM_ALU_SB_G1:
10678     case elfcpp::R_ARM_ALU_SB_G2:
10679     case elfcpp::R_ARM_LDR_PC_G0:
10680     case elfcpp::R_ARM_LDR_PC_G1:
10681     case elfcpp::R_ARM_LDR_PC_G2:
10682     case elfcpp::R_ARM_LDR_SB_G0:
10683     case elfcpp::R_ARM_LDR_SB_G1:
10684     case elfcpp::R_ARM_LDR_SB_G2:
10685     case elfcpp::R_ARM_LDRS_PC_G0:
10686     case elfcpp::R_ARM_LDRS_PC_G1:
10687     case elfcpp::R_ARM_LDRS_PC_G2:
10688     case elfcpp::R_ARM_LDRS_SB_G0:
10689     case elfcpp::R_ARM_LDRS_SB_G1:
10690     case elfcpp::R_ARM_LDRS_SB_G2:
10691     case elfcpp::R_ARM_LDC_PC_G0:
10692     case elfcpp::R_ARM_LDC_PC_G1:
10693     case elfcpp::R_ARM_LDC_PC_G2:
10694     case elfcpp::R_ARM_LDC_SB_G0:
10695     case elfcpp::R_ARM_LDC_SB_G1:
10696     case elfcpp::R_ARM_LDC_SB_G2:
10697       gold_error(_("cannot handle %s in a relocatable link"),
10698                  arp->name().c_str());
10699       break;
10700
10701     default:
10702       gold_unreachable();
10703     }
10704
10705   // Report any errors.
10706   switch (reloc_status)
10707     {
10708     case Arm_relocate_functions<big_endian>::STATUS_OKAY:
10709       break;
10710     case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
10711       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
10712                              _("relocation overflow in %s"),
10713                              arp->name().c_str());
10714       break;
10715     case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
10716       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
10717         _("unexpected opcode while processing relocation %s"),
10718         arp->name().c_str());
10719       break;
10720     default:
10721       gold_unreachable();
10722     }
10723 }
10724
10725 // Return the value to use for a dynamic symbol which requires special
10726 // treatment.  This is how we support equality comparisons of function
10727 // pointers across shared library boundaries, as described in the
10728 // processor specific ABI supplement.
10729
10730 template<bool big_endian>
10731 uint64_t
10732 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
10733 {
10734   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
10735   return this->plt_address_for_global(gsym);
10736 }
10737
10738 // Map platform-specific relocs to real relocs
10739 //
10740 template<bool big_endian>
10741 unsigned int
10742 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type) const
10743 {
10744   switch (r_type)
10745     {
10746     case elfcpp::R_ARM_TARGET1:
10747       return this->target1_reloc_;
10748
10749     case elfcpp::R_ARM_TARGET2:
10750       return this->target2_reloc_;
10751
10752     default:
10753       return r_type;
10754     }
10755 }
10756
10757 // Whether if two EABI versions V1 and V2 are compatible.
10758
10759 template<bool big_endian>
10760 bool
10761 Target_arm<big_endian>::are_eabi_versions_compatible(
10762     elfcpp::Elf_Word v1,
10763     elfcpp::Elf_Word v2)
10764 {
10765   // v4 and v5 are the same spec before and after it was released,
10766   // so allow mixing them.
10767   if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
10768       || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
10769       || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
10770     return true;
10771
10772   return v1 == v2;
10773 }
10774
10775 // Combine FLAGS from an input object called NAME and the processor-specific
10776 // flags in the ELF header of the output.  Much of this is adapted from the
10777 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
10778 // in bfd/elf32-arm.c.
10779
10780 template<bool big_endian>
10781 void
10782 Target_arm<big_endian>::merge_processor_specific_flags(
10783     const std::string& name,
10784     elfcpp::Elf_Word flags)
10785 {
10786   if (this->are_processor_specific_flags_set())
10787     {
10788       elfcpp::Elf_Word out_flags = this->processor_specific_flags();
10789
10790       // Nothing to merge if flags equal to those in output.
10791       if (flags == out_flags)
10792         return;
10793
10794       // Complain about various flag mismatches.
10795       elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
10796       elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
10797       if (!this->are_eabi_versions_compatible(version1, version2)
10798           && parameters->options().warn_mismatch())
10799         gold_error(_("Source object %s has EABI version %d but output has "
10800                      "EABI version %d."),
10801                    name.c_str(),
10802                    (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
10803                    (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
10804     }
10805   else
10806     {
10807       // If the input is the default architecture and had the default
10808       // flags then do not bother setting the flags for the output
10809       // architecture, instead allow future merges to do this.  If no
10810       // future merges ever set these flags then they will retain their
10811       // uninitialised values, which surprise surprise, correspond
10812       // to the default values.
10813       if (flags == 0)
10814         return;
10815
10816       // This is the first time, just copy the flags.
10817       // We only copy the EABI version for now.
10818       this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
10819     }
10820 }
10821
10822 // Adjust ELF file header.
10823 template<bool big_endian>
10824 void
10825 Target_arm<big_endian>::do_adjust_elf_header(
10826     unsigned char* view,
10827     int len)
10828 {
10829   gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
10830
10831   elfcpp::Ehdr<32, big_endian> ehdr(view);
10832   elfcpp::Elf_Word flags = this->processor_specific_flags();
10833   unsigned char e_ident[elfcpp::EI_NIDENT];
10834   memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
10835
10836   if (elfcpp::arm_eabi_version(flags)
10837       == elfcpp::EF_ARM_EABI_UNKNOWN)
10838     e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
10839   else
10840     e_ident[elfcpp::EI_OSABI] = 0;
10841   e_ident[elfcpp::EI_ABIVERSION] = 0;
10842
10843   // Do EF_ARM_BE8 adjustment.
10844   if (parameters->options().be8() && !big_endian)
10845     gold_error("BE8 images only valid in big-endian mode.");
10846   if (parameters->options().be8())
10847     {
10848       flags |= elfcpp::EF_ARM_BE8;
10849       this->set_processor_specific_flags(flags);
10850     }
10851
10852   // If we're working in EABI_VER5, set the hard/soft float ABI flags
10853   // as appropriate.
10854   if (elfcpp::arm_eabi_version(flags) == elfcpp::EF_ARM_EABI_VER5)
10855   {
10856     elfcpp::Elf_Half type = ehdr.get_e_type();
10857     if (type == elfcpp::ET_EXEC || type == elfcpp::ET_DYN)
10858       {
10859         Object_attribute* attr = this->get_aeabi_object_attribute(elfcpp::Tag_ABI_VFP_args);
10860         if (attr->int_value() == elfcpp::AEABI_VFP_args_vfp)
10861           flags |= elfcpp::EF_ARM_ABI_FLOAT_HARD;
10862         else
10863           flags |= elfcpp::EF_ARM_ABI_FLOAT_SOFT;
10864         this->set_processor_specific_flags(flags);
10865       }
10866   }
10867   elfcpp::Ehdr_write<32, big_endian> oehdr(view);
10868   oehdr.put_e_ident(e_ident);
10869   oehdr.put_e_flags(this->processor_specific_flags());
10870 }
10871
10872 // do_make_elf_object to override the same function in the base class.
10873 // We need to use a target-specific sub-class of
10874 // Sized_relobj_file<32, big_endian> to store ARM specific information.
10875 // Hence we need to have our own ELF object creation.
10876
10877 template<bool big_endian>
10878 Object*
10879 Target_arm<big_endian>::do_make_elf_object(
10880     const std::string& name,
10881     Input_file* input_file,
10882     off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
10883 {
10884   int et = ehdr.get_e_type();
10885   // ET_EXEC files are valid input for --just-symbols/-R,
10886   // and we treat them as relocatable objects.
10887   if (et == elfcpp::ET_REL
10888       || (et == elfcpp::ET_EXEC && input_file->just_symbols()))
10889     {
10890       Arm_relobj<big_endian>* obj =
10891         new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
10892       obj->setup();
10893       return obj;
10894     }
10895   else if (et == elfcpp::ET_DYN)
10896     {
10897       Sized_dynobj<32, big_endian>* obj =
10898         new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
10899       obj->setup();
10900       return obj;
10901     }
10902   else
10903     {
10904       gold_error(_("%s: unsupported ELF file type %d"),
10905                  name.c_str(), et);
10906       return NULL;
10907     }
10908 }
10909
10910 // Read the architecture from the Tag_also_compatible_with attribute, if any.
10911 // Returns -1 if no architecture could be read.
10912 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
10913
10914 template<bool big_endian>
10915 int
10916 Target_arm<big_endian>::get_secondary_compatible_arch(
10917     const Attributes_section_data* pasd)
10918 {
10919   const Object_attribute* known_attributes =
10920     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10921
10922   // Note: the tag and its argument below are uleb128 values, though
10923   // currently-defined values fit in one byte for each.
10924   const std::string& sv =
10925     known_attributes[elfcpp::Tag_also_compatible_with].string_value();
10926   if (sv.size() == 2
10927       && sv.data()[0] == elfcpp::Tag_CPU_arch
10928       && (sv.data()[1] & 128) != 128)
10929    return sv.data()[1];
10930
10931   // This tag is "safely ignorable", so don't complain if it looks funny.
10932   return -1;
10933 }
10934
10935 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10936 // The tag is removed if ARCH is -1.
10937 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10938
10939 template<bool big_endian>
10940 void
10941 Target_arm<big_endian>::set_secondary_compatible_arch(
10942     Attributes_section_data* pasd,
10943     int arch)
10944 {
10945   Object_attribute* known_attributes =
10946     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10947
10948   if (arch == -1)
10949     {
10950       known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10951       return;
10952     }
10953
10954   // Note: the tag and its argument below are uleb128 values, though
10955   // currently-defined values fit in one byte for each.
10956   char sv[3];
10957   sv[0] = elfcpp::Tag_CPU_arch;
10958   gold_assert(arch != 0);
10959   sv[1] = arch;
10960   sv[2] = '\0';
10961
10962   known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10963 }
10964
10965 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10966 // into account.
10967 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10968
10969 template<bool big_endian>
10970 int
10971 Target_arm<big_endian>::tag_cpu_arch_combine(
10972     const char* name,
10973     int oldtag,
10974     int* secondary_compat_out,
10975     int newtag,
10976     int secondary_compat)
10977 {
10978 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10979   static const int v6t2[] =
10980     {
10981       T(V6T2),   // PRE_V4.
10982       T(V6T2),   // V4.
10983       T(V6T2),   // V4T.
10984       T(V6T2),   // V5T.
10985       T(V6T2),   // V5TE.
10986       T(V6T2),   // V5TEJ.
10987       T(V6T2),   // V6.
10988       T(V7),     // V6KZ.
10989       T(V6T2)    // V6T2.
10990     };
10991   static const int v6k[] =
10992     {
10993       T(V6K),    // PRE_V4.
10994       T(V6K),    // V4.
10995       T(V6K),    // V4T.
10996       T(V6K),    // V5T.
10997       T(V6K),    // V5TE.
10998       T(V6K),    // V5TEJ.
10999       T(V6K),    // V6.
11000       T(V6KZ),   // V6KZ.
11001       T(V7),     // V6T2.
11002       T(V6K)     // V6K.
11003     };
11004   static const int v7[] =
11005     {
11006       T(V7),     // PRE_V4.
11007       T(V7),     // V4.
11008       T(V7),     // V4T.
11009       T(V7),     // V5T.
11010       T(V7),     // V5TE.
11011       T(V7),     // V5TEJ.
11012       T(V7),     // V6.
11013       T(V7),     // V6KZ.
11014       T(V7),     // V6T2.
11015       T(V7),     // V6K.
11016       T(V7)      // V7.
11017     };
11018   static const int v6_m[] =
11019     {
11020       -1,        // PRE_V4.
11021       -1,        // V4.
11022       T(V6K),    // V4T.
11023       T(V6K),    // V5T.
11024       T(V6K),    // V5TE.
11025       T(V6K),    // V5TEJ.
11026       T(V6K),    // V6.
11027       T(V6KZ),   // V6KZ.
11028       T(V7),     // V6T2.
11029       T(V6K),    // V6K.
11030       T(V7),     // V7.
11031       T(V6_M)    // V6_M.
11032     };
11033   static const int v6s_m[] =
11034     {
11035       -1,        // PRE_V4.
11036       -1,        // V4.
11037       T(V6K),    // V4T.
11038       T(V6K),    // V5T.
11039       T(V6K),    // V5TE.
11040       T(V6K),    // V5TEJ.
11041       T(V6K),    // V6.
11042       T(V6KZ),   // V6KZ.
11043       T(V7),     // V6T2.
11044       T(V6K),    // V6K.
11045       T(V7),     // V7.
11046       T(V6S_M),  // V6_M.
11047       T(V6S_M)   // V6S_M.
11048     };
11049   static const int v7e_m[] =
11050     {
11051       -1,       // PRE_V4.
11052       -1,       // V4.
11053       T(V7E_M), // V4T.
11054       T(V7E_M), // V5T.
11055       T(V7E_M), // V5TE.
11056       T(V7E_M), // V5TEJ.
11057       T(V7E_M), // V6.
11058       T(V7E_M), // V6KZ.
11059       T(V7E_M), // V6T2.
11060       T(V7E_M), // V6K.
11061       T(V7E_M), // V7.
11062       T(V7E_M), // V6_M.
11063       T(V7E_M), // V6S_M.
11064       T(V7E_M)  // V7E_M.
11065     };
11066   static const int v8[] =
11067     {
11068       T(V8),   // PRE_V4.
11069       T(V8),   // V4.
11070       T(V8),   // V4T.
11071       T(V8),   // V5T.
11072       T(V8),   // V5TE.
11073       T(V8),   // V5TEJ.
11074       T(V8),   // V6.
11075       T(V8),   // V6KZ.
11076       T(V8),   // V6T2.
11077       T(V8),   // V6K.
11078       T(V8),   // V7.
11079       T(V8),   // V6_M.
11080       T(V8),   // V6S_M.
11081       T(V8),   // V7E_M.
11082       T(V8)    // V8.
11083     };
11084   static const int v4t_plus_v6_m[] =
11085     {
11086       -1,               // PRE_V4.
11087       -1,               // V4.
11088       T(V4T),           // V4T.
11089       T(V5T),           // V5T.
11090       T(V5TE),          // V5TE.
11091       T(V5TEJ),         // V5TEJ.
11092       T(V6),            // V6.
11093       T(V6KZ),          // V6KZ.
11094       T(V6T2),          // V6T2.
11095       T(V6K),           // V6K.
11096       T(V7),            // V7.
11097       T(V6_M),          // V6_M.
11098       T(V6S_M),         // V6S_M.
11099       T(V7E_M),         // V7E_M.
11100       T(V8),            // V8.
11101       T(V4T_PLUS_V6_M)  // V4T plus V6_M.
11102     };
11103   static const int* comb[] =
11104     {
11105       v6t2,
11106       v6k,
11107       v7,
11108       v6_m,
11109       v6s_m,
11110       v7e_m,
11111       v8,
11112       // Pseudo-architecture.
11113       v4t_plus_v6_m
11114     };
11115
11116   // Check we've not got a higher architecture than we know about.
11117
11118   if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
11119     {
11120       gold_error(_("%s: unknown CPU architecture"), name);
11121       return -1;
11122     }
11123
11124   // Override old tag if we have a Tag_also_compatible_with on the output.
11125
11126   if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
11127       || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
11128     oldtag = T(V4T_PLUS_V6_M);
11129
11130   // And override the new tag if we have a Tag_also_compatible_with on the
11131   // input.
11132
11133   if ((newtag == T(V6_M) && secondary_compat == T(V4T))
11134       || (newtag == T(V4T) && secondary_compat == T(V6_M)))
11135     newtag = T(V4T_PLUS_V6_M);
11136
11137   // Architectures before V6KZ add features monotonically.
11138   int tagh = std::max(oldtag, newtag);
11139   if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
11140     return tagh;
11141
11142   int tagl = std::min(oldtag, newtag);
11143   int result = comb[tagh - T(V6T2)][tagl];
11144
11145   // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
11146   // as the canonical version.
11147   if (result == T(V4T_PLUS_V6_M))
11148     {
11149       result = T(V4T);
11150       *secondary_compat_out = T(V6_M);
11151     }
11152   else
11153     *secondary_compat_out = -1;
11154
11155   if (result == -1)
11156     {
11157       gold_error(_("%s: conflicting CPU architectures %d/%d"),
11158                  name, oldtag, newtag);
11159       return -1;
11160     }
11161
11162   return result;
11163 #undef T
11164 }
11165
11166 // Helper to print AEABI enum tag value.
11167
11168 template<bool big_endian>
11169 std::string
11170 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
11171 {
11172   static const char* aeabi_enum_names[] =
11173     { "", "variable-size", "32-bit", "" };
11174   const size_t aeabi_enum_names_size =
11175     sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
11176
11177   if (value < aeabi_enum_names_size)
11178     return std::string(aeabi_enum_names[value]);
11179   else
11180     {
11181       char buffer[100];
11182       sprintf(buffer, "<unknown value %u>", value);
11183       return std::string(buffer);
11184     }
11185 }
11186
11187 // Return the string value to store in TAG_CPU_name.
11188
11189 template<bool big_endian>
11190 std::string
11191 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
11192 {
11193   static const char* name_table[] = {
11194     // These aren't real CPU names, but we can't guess
11195     // that from the architecture version alone.
11196    "Pre v4",
11197    "ARM v4",
11198    "ARM v4T",
11199    "ARM v5T",
11200    "ARM v5TE",
11201    "ARM v5TEJ",
11202    "ARM v6",
11203    "ARM v6KZ",
11204    "ARM v6T2",
11205    "ARM v6K",
11206    "ARM v7",
11207    "ARM v6-M",
11208    "ARM v6S-M",
11209    "ARM v7E-M",
11210    "ARM v8"
11211  };
11212  const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
11213
11214   if (value < name_table_size)
11215     return std::string(name_table[value]);
11216   else
11217     {
11218       char buffer[100];
11219       sprintf(buffer, "<unknown CPU value %u>", value);
11220       return std::string(buffer);
11221     }
11222 }
11223
11224 // Query attributes object to see if integer divide instructions may be
11225 // present in an object.
11226
11227 template<bool big_endian>
11228 bool
11229 Target_arm<big_endian>::attributes_accept_div(int arch, int profile,
11230     const Object_attribute* div_attr)
11231 {
11232   switch (div_attr->int_value())
11233     {
11234     case 0:
11235       // Integer divide allowed if instruction contained in
11236       // architecture.
11237       if (arch == elfcpp::TAG_CPU_ARCH_V7 && (profile == 'R' || profile == 'M'))
11238         return true;
11239       else if (arch >= elfcpp::TAG_CPU_ARCH_V7E_M)
11240         return true;
11241       else
11242         return false;
11243
11244     case 1:
11245       // Integer divide explicitly prohibited.
11246       return false;
11247
11248     default:
11249       // Unrecognised case - treat as allowing divide everywhere.
11250     case 2:
11251       // Integer divide allowed in ARM state.
11252       return true;
11253     }
11254 }
11255
11256 // Query attributes object to see if integer divide instructions are
11257 // forbidden to be in the object.  This is not the inverse of
11258 // attributes_accept_div.
11259
11260 template<bool big_endian>
11261 bool
11262 Target_arm<big_endian>::attributes_forbid_div(const Object_attribute* div_attr)
11263 {
11264   return div_attr->int_value() == 1;
11265 }
11266
11267 // Merge object attributes from input file called NAME with those of the
11268 // output.  The input object attributes are in the object pointed by PASD.
11269
11270 template<bool big_endian>
11271 void
11272 Target_arm<big_endian>::merge_object_attributes(
11273     const char* name,
11274     const Attributes_section_data* pasd)
11275 {
11276   // Return if there is no attributes section data.
11277   if (pasd == NULL)
11278     return;
11279
11280   // If output has no object attributes, just copy.
11281   const int vendor = Object_attribute::OBJ_ATTR_PROC;
11282   if (this->attributes_section_data_ == NULL)
11283     {
11284       this->attributes_section_data_ = new Attributes_section_data(*pasd);
11285       Object_attribute* out_attr =
11286         this->attributes_section_data_->known_attributes(vendor);
11287
11288       // We do not output objects with Tag_MPextension_use_legacy - we move
11289       //  the attribute's value to Tag_MPextension_use.  */
11290       if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
11291         {
11292           if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
11293               && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
11294                 != out_attr[elfcpp::Tag_MPextension_use].int_value())
11295             {
11296               gold_error(_("%s has both the current and legacy "
11297                            "Tag_MPextension_use attributes"),
11298                          name);
11299             }
11300
11301           out_attr[elfcpp::Tag_MPextension_use] =
11302             out_attr[elfcpp::Tag_MPextension_use_legacy];
11303           out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
11304           out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
11305         }
11306
11307       return;
11308     }
11309
11310   const Object_attribute* in_attr = pasd->known_attributes(vendor);
11311   Object_attribute* out_attr =
11312     this->attributes_section_data_->known_attributes(vendor);
11313
11314   // This needs to happen before Tag_ABI_FP_number_model is merged.  */
11315   if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
11316       != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
11317     {
11318       // Ignore mismatches if the object doesn't use floating point.  */
11319       if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
11320           == elfcpp::AEABI_FP_number_model_none
11321           || (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
11322               != elfcpp::AEABI_FP_number_model_none
11323               && out_attr[elfcpp::Tag_ABI_VFP_args].int_value()
11324                  == elfcpp::AEABI_VFP_args_compatible))
11325         out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
11326             in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
11327       else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
11328                != elfcpp::AEABI_FP_number_model_none
11329                && in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
11330                   != elfcpp::AEABI_VFP_args_compatible
11331                && parameters->options().warn_mismatch())
11332         gold_error(_("%s uses VFP register arguments, output does not"),
11333                    name);
11334     }
11335
11336   for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
11337     {
11338       // Merge this attribute with existing attributes.
11339       switch (i)
11340         {
11341         case elfcpp::Tag_CPU_raw_name:
11342         case elfcpp::Tag_CPU_name:
11343           // These are merged after Tag_CPU_arch.
11344           break;
11345
11346         case elfcpp::Tag_ABI_optimization_goals:
11347         case elfcpp::Tag_ABI_FP_optimization_goals:
11348           // Use the first value seen.
11349           break;
11350
11351         case elfcpp::Tag_CPU_arch:
11352           {
11353             unsigned int saved_out_attr = out_attr->int_value();
11354             // Merge Tag_CPU_arch and Tag_also_compatible_with.
11355             int secondary_compat =
11356               this->get_secondary_compatible_arch(pasd);
11357             int secondary_compat_out =
11358               this->get_secondary_compatible_arch(
11359                   this->attributes_section_data_);
11360             out_attr[i].set_int_value(
11361                 tag_cpu_arch_combine(name, out_attr[i].int_value(),
11362                                      &secondary_compat_out,
11363                                      in_attr[i].int_value(),
11364                                      secondary_compat));
11365             this->set_secondary_compatible_arch(this->attributes_section_data_,
11366                                                 secondary_compat_out);
11367
11368             // Merge Tag_CPU_name and Tag_CPU_raw_name.
11369             if (out_attr[i].int_value() == saved_out_attr)
11370               ; // Leave the names alone.
11371             else if (out_attr[i].int_value() == in_attr[i].int_value())
11372               {
11373                 // The output architecture has been changed to match the
11374                 // input architecture.  Use the input names.
11375                 out_attr[elfcpp::Tag_CPU_name].set_string_value(
11376                     in_attr[elfcpp::Tag_CPU_name].string_value());
11377                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
11378                     in_attr[elfcpp::Tag_CPU_raw_name].string_value());
11379               }
11380             else
11381               {
11382                 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
11383                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
11384               }
11385
11386             // If we still don't have a value for Tag_CPU_name,
11387             // make one up now.  Tag_CPU_raw_name remains blank.
11388             if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
11389               {
11390                 const std::string cpu_name =
11391                   this->tag_cpu_name_value(out_attr[i].int_value());
11392                 // FIXME:  If we see an unknown CPU, this will be set
11393                 // to "<unknown CPU n>", where n is the attribute value.
11394                 // This is different from BFD, which leaves the name alone.
11395                 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
11396               }
11397           }
11398           break;
11399
11400         case elfcpp::Tag_ARM_ISA_use:
11401         case elfcpp::Tag_THUMB_ISA_use:
11402         case elfcpp::Tag_WMMX_arch:
11403         case elfcpp::Tag_Advanced_SIMD_arch:
11404           // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
11405         case elfcpp::Tag_ABI_FP_rounding:
11406         case elfcpp::Tag_ABI_FP_exceptions:
11407         case elfcpp::Tag_ABI_FP_user_exceptions:
11408         case elfcpp::Tag_ABI_FP_number_model:
11409         case elfcpp::Tag_VFP_HP_extension:
11410         case elfcpp::Tag_CPU_unaligned_access:
11411         case elfcpp::Tag_T2EE_use:
11412         case elfcpp::Tag_Virtualization_use:
11413         case elfcpp::Tag_MPextension_use:
11414           // Use the largest value specified.
11415           if (in_attr[i].int_value() > out_attr[i].int_value())
11416             out_attr[i].set_int_value(in_attr[i].int_value());
11417           break;
11418
11419         case elfcpp::Tag_ABI_align8_preserved:
11420         case elfcpp::Tag_ABI_PCS_RO_data:
11421           // Use the smallest value specified.
11422           if (in_attr[i].int_value() < out_attr[i].int_value())
11423             out_attr[i].set_int_value(in_attr[i].int_value());
11424           break;
11425
11426         case elfcpp::Tag_ABI_align8_needed:
11427           if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
11428               && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
11429                   || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
11430                       == 0)))
11431             {
11432               // This error message should be enabled once all non-conforming
11433               // binaries in the toolchain have had the attributes set
11434               // properly.
11435               // gold_error(_("output 8-byte data alignment conflicts with %s"),
11436               //            name);
11437             }
11438           // Fall through.
11439         case elfcpp::Tag_ABI_FP_denormal:
11440         case elfcpp::Tag_ABI_PCS_GOT_use:
11441           {
11442             // These tags have 0 = don't care, 1 = strong requirement,
11443             // 2 = weak requirement.
11444             static const int order_021[3] = {0, 2, 1};
11445
11446             // Use the "greatest" from the sequence 0, 2, 1, or the largest
11447             // value if greater than 2 (for future-proofing).
11448             if ((in_attr[i].int_value() > 2
11449                  && in_attr[i].int_value() > out_attr[i].int_value())
11450                 || (in_attr[i].int_value() <= 2
11451                     && out_attr[i].int_value() <= 2
11452                     && (order_021[in_attr[i].int_value()]
11453                         > order_021[out_attr[i].int_value()])))
11454               out_attr[i].set_int_value(in_attr[i].int_value());
11455           }
11456           break;
11457
11458         case elfcpp::Tag_CPU_arch_profile:
11459           if (out_attr[i].int_value() != in_attr[i].int_value())
11460             {
11461               // 0 will merge with anything.
11462               // 'A' and 'S' merge to 'A'.
11463               // 'R' and 'S' merge to 'R'.
11464               // 'M' and 'A|R|S' is an error.
11465               if (out_attr[i].int_value() == 0
11466                   || (out_attr[i].int_value() == 'S'
11467                       && (in_attr[i].int_value() == 'A'
11468                           || in_attr[i].int_value() == 'R')))
11469                 out_attr[i].set_int_value(in_attr[i].int_value());
11470               else if (in_attr[i].int_value() == 0
11471                        || (in_attr[i].int_value() == 'S'
11472                            && (out_attr[i].int_value() == 'A'
11473                                || out_attr[i].int_value() == 'R')))
11474                 ; // Do nothing.
11475               else if (parameters->options().warn_mismatch())
11476                 {
11477                   gold_error
11478                     (_("conflicting architecture profiles %c/%c"),
11479                      in_attr[i].int_value() ? in_attr[i].int_value() : '0',
11480                      out_attr[i].int_value() ? out_attr[i].int_value() : '0');
11481                 }
11482             }
11483           break;
11484         case elfcpp::Tag_VFP_arch:
11485             {
11486               static const struct
11487               {
11488                   int ver;
11489                   int regs;
11490               } vfp_versions[7] =
11491                 {
11492                   {0, 0},
11493                   {1, 16},
11494                   {2, 16},
11495                   {3, 32},
11496                   {3, 16},
11497                   {4, 32},
11498                   {4, 16}
11499                 };
11500
11501               // Values greater than 6 aren't defined, so just pick the
11502               // biggest.
11503               if (in_attr[i].int_value() > 6
11504                   && in_attr[i].int_value() > out_attr[i].int_value())
11505                 {
11506                   *out_attr = *in_attr;
11507                   break;
11508                 }
11509               // The output uses the superset of input features
11510               // (ISA version) and registers.
11511               int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
11512                                  vfp_versions[out_attr[i].int_value()].ver);
11513               int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
11514                                   vfp_versions[out_attr[i].int_value()].regs);
11515               // This assumes all possible supersets are also a valid
11516               // options.
11517               int newval;
11518               for (newval = 6; newval > 0; newval--)
11519                 {
11520                   if (regs == vfp_versions[newval].regs
11521                       && ver == vfp_versions[newval].ver)
11522                     break;
11523                 }
11524               out_attr[i].set_int_value(newval);
11525             }
11526           break;
11527         case elfcpp::Tag_PCS_config:
11528           if (out_attr[i].int_value() == 0)
11529             out_attr[i].set_int_value(in_attr[i].int_value());
11530           else if (in_attr[i].int_value() != 0
11531                    && out_attr[i].int_value() != 0
11532                    && parameters->options().warn_mismatch())
11533             {
11534               // It's sometimes ok to mix different configs, so this is only
11535               // a warning.
11536               gold_warning(_("%s: conflicting platform configuration"), name);
11537             }
11538           break;
11539         case elfcpp::Tag_ABI_PCS_R9_use:
11540           if (in_attr[i].int_value() != out_attr[i].int_value()
11541               && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
11542               && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
11543               && parameters->options().warn_mismatch())
11544             {
11545               gold_error(_("%s: conflicting use of R9"), name);
11546             }
11547           if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
11548             out_attr[i].set_int_value(in_attr[i].int_value());
11549           break;
11550         case elfcpp::Tag_ABI_PCS_RW_data:
11551           if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
11552               && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
11553                   != elfcpp::AEABI_R9_SB)
11554               && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
11555                   != elfcpp::AEABI_R9_unused)
11556               && parameters->options().warn_mismatch())
11557             {
11558               gold_error(_("%s: SB relative addressing conflicts with use "
11559                            "of R9"),
11560                            name);
11561             }
11562           // Use the smallest value specified.
11563           if (in_attr[i].int_value() < out_attr[i].int_value())
11564             out_attr[i].set_int_value(in_attr[i].int_value());
11565           break;
11566         case elfcpp::Tag_ABI_PCS_wchar_t:
11567           if (out_attr[i].int_value()
11568               && in_attr[i].int_value()
11569               && out_attr[i].int_value() != in_attr[i].int_value()
11570               && parameters->options().warn_mismatch()
11571               && parameters->options().wchar_size_warning())
11572             {
11573               gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
11574                              "use %u-byte wchar_t; use of wchar_t values "
11575                              "across objects may fail"),
11576                            name, in_attr[i].int_value(),
11577                            out_attr[i].int_value());
11578             }
11579           else if (in_attr[i].int_value() && !out_attr[i].int_value())
11580             out_attr[i].set_int_value(in_attr[i].int_value());
11581           break;
11582         case elfcpp::Tag_ABI_enum_size:
11583           if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
11584             {
11585               if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
11586                   || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
11587                 {
11588                   // The existing object is compatible with anything.
11589                   // Use whatever requirements the new object has.
11590                   out_attr[i].set_int_value(in_attr[i].int_value());
11591                 }
11592               else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
11593                        && out_attr[i].int_value() != in_attr[i].int_value()
11594                        && parameters->options().warn_mismatch()
11595                        && parameters->options().enum_size_warning())
11596                 {
11597                   unsigned int in_value = in_attr[i].int_value();
11598                   unsigned int out_value = out_attr[i].int_value();
11599                   gold_warning(_("%s uses %s enums yet the output is to use "
11600                                  "%s enums; use of enum values across objects "
11601                                  "may fail"),
11602                                name,
11603                                this->aeabi_enum_name(in_value).c_str(),
11604                                this->aeabi_enum_name(out_value).c_str());
11605                 }
11606             }
11607           break;
11608         case elfcpp::Tag_ABI_VFP_args:
11609           // Already done.
11610           break;
11611         case elfcpp::Tag_ABI_WMMX_args:
11612           if (in_attr[i].int_value() != out_attr[i].int_value()
11613               && parameters->options().warn_mismatch())
11614             {
11615               gold_error(_("%s uses iWMMXt register arguments, output does "
11616                            "not"),
11617                          name);
11618             }
11619           break;
11620         case Object_attribute::Tag_compatibility:
11621           // Merged in target-independent code.
11622           break;
11623         case elfcpp::Tag_ABI_HardFP_use:
11624           // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
11625           if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
11626               || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
11627             out_attr[i].set_int_value(3);
11628           else if (in_attr[i].int_value() > out_attr[i].int_value())
11629             out_attr[i].set_int_value(in_attr[i].int_value());
11630           break;
11631         case elfcpp::Tag_ABI_FP_16bit_format:
11632           if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
11633             {
11634               if (in_attr[i].int_value() != out_attr[i].int_value()
11635                   && parameters->options().warn_mismatch())
11636                 gold_error(_("fp16 format mismatch between %s and output"),
11637                            name);
11638             }
11639           if (in_attr[i].int_value() != 0)
11640             out_attr[i].set_int_value(in_attr[i].int_value());
11641           break;
11642
11643         case elfcpp::Tag_DIV_use:
11644           {
11645             // A value of zero on input means that the divide
11646             // instruction may be used if available in the base
11647             // architecture as specified via Tag_CPU_arch and
11648             // Tag_CPU_arch_profile.  A value of 1 means that the user
11649             // did not want divide instructions.  A value of 2
11650             // explicitly means that divide instructions were allowed
11651             // in ARM and Thumb state.
11652             int arch = this->
11653               get_aeabi_object_attribute(elfcpp::Tag_CPU_arch)->
11654               int_value();
11655             int profile = this->
11656               get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile)->
11657               int_value();
11658             if (in_attr[i].int_value() == out_attr[i].int_value())
11659               {
11660                 // Do nothing.
11661               }
11662             else if (attributes_forbid_div(&in_attr[i])
11663                      && !attributes_accept_div(arch, profile, &out_attr[i]))
11664               out_attr[i].set_int_value(1);
11665             else if (attributes_forbid_div(&out_attr[i])
11666                      && attributes_accept_div(arch, profile, &in_attr[i]))
11667               out_attr[i].set_int_value(in_attr[i].int_value());
11668             else if (in_attr[i].int_value() == 2)
11669               out_attr[i].set_int_value(in_attr[i].int_value());
11670           }
11671           break;
11672
11673         case elfcpp::Tag_MPextension_use_legacy:
11674           // We don't output objects with Tag_MPextension_use_legacy - we
11675           // move the value to Tag_MPextension_use.
11676           if (in_attr[i].int_value() != 0
11677               && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
11678             {
11679               if (in_attr[elfcpp::Tag_MPextension_use].int_value()
11680                   != in_attr[i].int_value())
11681                 {
11682                   gold_error(_("%s has both the current and legacy "
11683                                "Tag_MPextension_use attributes"),
11684                              name);
11685                 }
11686             }
11687
11688           if (in_attr[i].int_value()
11689               > out_attr[elfcpp::Tag_MPextension_use].int_value())
11690             out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
11691
11692           break;
11693
11694         case elfcpp::Tag_nodefaults:
11695           // This tag is set if it exists, but the value is unused (and is
11696           // typically zero).  We don't actually need to do anything here -
11697           // the merge happens automatically when the type flags are merged
11698           // below.
11699           break;
11700         case elfcpp::Tag_also_compatible_with:
11701           // Already done in Tag_CPU_arch.
11702           break;
11703         case elfcpp::Tag_conformance:
11704           // Keep the attribute if it matches.  Throw it away otherwise.
11705           // No attribute means no claim to conform.
11706           if (in_attr[i].string_value() != out_attr[i].string_value())
11707             out_attr[i].set_string_value("");
11708           break;
11709
11710         default:
11711           {
11712             const char* err_object = NULL;
11713
11714             // The "known_obj_attributes" table does contain some undefined
11715             // attributes.  Ensure that there are unused.
11716             if (out_attr[i].int_value() != 0
11717                 || out_attr[i].string_value() != "")
11718               err_object = "output";
11719             else if (in_attr[i].int_value() != 0
11720                      || in_attr[i].string_value() != "")
11721               err_object = name;
11722
11723             if (err_object != NULL
11724                 && parameters->options().warn_mismatch())
11725               {
11726                 // Attribute numbers >=64 (mod 128) can be safely ignored.
11727                 if ((i & 127) < 64)
11728                   gold_error(_("%s: unknown mandatory EABI object attribute "
11729                                "%d"),
11730                              err_object, i);
11731                 else
11732                   gold_warning(_("%s: unknown EABI object attribute %d"),
11733                                err_object, i);
11734               }
11735
11736             // Only pass on attributes that match in both inputs.
11737             if (!in_attr[i].matches(out_attr[i]))
11738               {
11739                 out_attr[i].set_int_value(0);
11740                 out_attr[i].set_string_value("");
11741               }
11742           }
11743         }
11744
11745       // If out_attr was copied from in_attr then it won't have a type yet.
11746       if (in_attr[i].type() && !out_attr[i].type())
11747         out_attr[i].set_type(in_attr[i].type());
11748     }
11749
11750   // Merge Tag_compatibility attributes and any common GNU ones.
11751   this->attributes_section_data_->merge(name, pasd);
11752
11753   // Check for any attributes not known on ARM.
11754   typedef Vendor_object_attributes::Other_attributes Other_attributes;
11755   const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
11756   Other_attributes::const_iterator in_iter = in_other_attributes->begin();
11757   Other_attributes* out_other_attributes =
11758     this->attributes_section_data_->other_attributes(vendor);
11759   Other_attributes::iterator out_iter = out_other_attributes->begin();
11760
11761   while (in_iter != in_other_attributes->end()
11762          || out_iter != out_other_attributes->end())
11763     {
11764       const char* err_object = NULL;
11765       int err_tag = 0;
11766
11767       // The tags for each list are in numerical order.
11768       // If the tags are equal, then merge.
11769       if (out_iter != out_other_attributes->end()
11770           && (in_iter == in_other_attributes->end()
11771               || in_iter->first > out_iter->first))
11772         {
11773           // This attribute only exists in output.  We can't merge, and we
11774           // don't know what the tag means, so delete it.
11775           err_object = "output";
11776           err_tag = out_iter->first;
11777           int saved_tag = out_iter->first;
11778           delete out_iter->second;
11779           out_other_attributes->erase(out_iter);
11780           out_iter = out_other_attributes->upper_bound(saved_tag);
11781         }
11782       else if (in_iter != in_other_attributes->end()
11783                && (out_iter != out_other_attributes->end()
11784                    || in_iter->first < out_iter->first))
11785         {
11786           // This attribute only exists in input. We can't merge, and we
11787           // don't know what the tag means, so ignore it.
11788           err_object = name;
11789           err_tag = in_iter->first;
11790           ++in_iter;
11791         }
11792       else // The tags are equal.
11793         {
11794           // As present, all attributes in the list are unknown, and
11795           // therefore can't be merged meaningfully.
11796           err_object = "output";
11797           err_tag = out_iter->first;
11798
11799           //  Only pass on attributes that match in both inputs.
11800           if (!in_iter->second->matches(*(out_iter->second)))
11801             {
11802               // No match.  Delete the attribute.
11803               int saved_tag = out_iter->first;
11804               delete out_iter->second;
11805               out_other_attributes->erase(out_iter);
11806               out_iter = out_other_attributes->upper_bound(saved_tag);
11807             }
11808           else
11809             {
11810               // Matched.  Keep the attribute and move to the next.
11811               ++out_iter;
11812               ++in_iter;
11813             }
11814         }
11815
11816       if (err_object && parameters->options().warn_mismatch())
11817         {
11818           // Attribute numbers >=64 (mod 128) can be safely ignored.  */
11819           if ((err_tag & 127) < 64)
11820             {
11821               gold_error(_("%s: unknown mandatory EABI object attribute %d"),
11822                          err_object, err_tag);
11823             }
11824           else
11825             {
11826               gold_warning(_("%s: unknown EABI object attribute %d"),
11827                            err_object, err_tag);
11828             }
11829         }
11830     }
11831 }
11832
11833 // Stub-generation methods for Target_arm.
11834
11835 // Make a new Arm_input_section object.
11836
11837 template<bool big_endian>
11838 Arm_input_section<big_endian>*
11839 Target_arm<big_endian>::new_arm_input_section(
11840     Relobj* relobj,
11841     unsigned int shndx)
11842 {
11843   Section_id sid(relobj, shndx);
11844
11845   Arm_input_section<big_endian>* arm_input_section =
11846     new Arm_input_section<big_endian>(relobj, shndx);
11847   arm_input_section->init();
11848
11849   // Register new Arm_input_section in map for look-up.
11850   std::pair<typename Arm_input_section_map::iterator, bool> ins =
11851     this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
11852
11853   // Make sure that it we have not created another Arm_input_section
11854   // for this input section already.
11855   gold_assert(ins.second);
11856
11857   return arm_input_section;
11858 }
11859
11860 // Find the Arm_input_section object corresponding to the SHNDX-th input
11861 // section of RELOBJ.
11862
11863 template<bool big_endian>
11864 Arm_input_section<big_endian>*
11865 Target_arm<big_endian>::find_arm_input_section(
11866     Relobj* relobj,
11867     unsigned int shndx) const
11868 {
11869   Section_id sid(relobj, shndx);
11870   typename Arm_input_section_map::const_iterator p =
11871     this->arm_input_section_map_.find(sid);
11872   return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
11873 }
11874
11875 // Make a new stub table.
11876
11877 template<bool big_endian>
11878 Stub_table<big_endian>*
11879 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
11880 {
11881   Stub_table<big_endian>* stub_table =
11882     new Stub_table<big_endian>(owner);
11883   this->stub_tables_.push_back(stub_table);
11884
11885   stub_table->set_address(owner->address() + owner->data_size());
11886   stub_table->set_file_offset(owner->offset() + owner->data_size());
11887   stub_table->finalize_data_size();
11888
11889   return stub_table;
11890 }
11891
11892 // Scan a relocation for stub generation.
11893
11894 template<bool big_endian>
11895 void
11896 Target_arm<big_endian>::scan_reloc_for_stub(
11897     const Relocate_info<32, big_endian>* relinfo,
11898     unsigned int r_type,
11899     const Sized_symbol<32>* gsym,
11900     unsigned int r_sym,
11901     const Symbol_value<32>* psymval,
11902     elfcpp::Elf_types<32>::Elf_Swxword addend,
11903     Arm_address address)
11904 {
11905   const Arm_relobj<big_endian>* arm_relobj =
11906     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11907
11908   bool target_is_thumb;
11909   Symbol_value<32> symval;
11910   if (gsym != NULL)
11911     {
11912       // This is a global symbol.  Determine if we use PLT and if the
11913       // final target is THUMB.
11914       if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
11915         {
11916           // This uses a PLT, change the symbol value.
11917           symval.set_output_value(this->plt_address_for_global(gsym));
11918           psymval = &symval;
11919           target_is_thumb = false;
11920         }
11921       else if (gsym->is_undefined())
11922         // There is no need to generate a stub symbol is undefined.
11923         return;
11924       else
11925         {
11926           target_is_thumb =
11927             ((gsym->type() == elfcpp::STT_ARM_TFUNC)
11928              || (gsym->type() == elfcpp::STT_FUNC
11929                  && !gsym->is_undefined()
11930                  && ((psymval->value(arm_relobj, 0) & 1) != 0)));
11931         }
11932     }
11933   else
11934     {
11935       // This is a local symbol.  Determine if the final target is THUMB.
11936       target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
11937     }
11938
11939   // Strip LSB if this points to a THUMB target.
11940   const Arm_reloc_property* reloc_property =
11941     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
11942   gold_assert(reloc_property != NULL);
11943   if (target_is_thumb
11944       && reloc_property->uses_thumb_bit()
11945       && ((psymval->value(arm_relobj, 0) & 1) != 0))
11946     {
11947       Arm_address stripped_value =
11948         psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
11949       symval.set_output_value(stripped_value);
11950       psymval = &symval;
11951     }
11952
11953   // Get the symbol value.
11954   Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
11955
11956   // Owing to pipelining, the PC relative branches below actually skip
11957   // two instructions when the branch offset is 0.
11958   Arm_address destination;
11959   switch (r_type)
11960     {
11961     case elfcpp::R_ARM_CALL:
11962     case elfcpp::R_ARM_JUMP24:
11963     case elfcpp::R_ARM_PLT32:
11964       // ARM branches.
11965       destination = value + addend + 8;
11966       break;
11967     case elfcpp::R_ARM_THM_CALL:
11968     case elfcpp::R_ARM_THM_XPC22:
11969     case elfcpp::R_ARM_THM_JUMP24:
11970     case elfcpp::R_ARM_THM_JUMP19:
11971       // THUMB branches.
11972       destination = value + addend + 4;
11973       break;
11974     default:
11975       gold_unreachable();
11976     }
11977
11978   Reloc_stub* stub = NULL;
11979   Stub_type stub_type =
11980     Reloc_stub::stub_type_for_reloc(r_type, address, destination,
11981                                     target_is_thumb);
11982   if (stub_type != arm_stub_none)
11983     {
11984       // Try looking up an existing stub from a stub table.
11985       Stub_table<big_endian>* stub_table =
11986         arm_relobj->stub_table(relinfo->data_shndx);
11987       gold_assert(stub_table != NULL);
11988
11989       // Locate stub by destination.
11990       Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
11991
11992       // Create a stub if there is not one already
11993       stub = stub_table->find_reloc_stub(stub_key);
11994       if (stub == NULL)
11995         {
11996           // create a new stub and add it to stub table.
11997           stub = this->stub_factory().make_reloc_stub(stub_type);
11998           stub_table->add_reloc_stub(stub, stub_key);
11999         }
12000
12001       // Record the destination address.
12002       stub->set_destination_address(destination
12003                                     | (target_is_thumb ? 1 : 0));
12004     }
12005
12006   // For Cortex-A8, we need to record a relocation at 4K page boundary.
12007   if (this->fix_cortex_a8_
12008       && (r_type == elfcpp::R_ARM_THM_JUMP24
12009           || r_type == elfcpp::R_ARM_THM_JUMP19
12010           || r_type == elfcpp::R_ARM_THM_CALL
12011           || r_type == elfcpp::R_ARM_THM_XPC22)
12012       && (address & 0xfffU) == 0xffeU)
12013     {
12014       // Found a candidate.  Note we haven't checked the destination is
12015       // within 4K here: if we do so (and don't create a record) we can't
12016       // tell that a branch should have been relocated when scanning later.
12017       this->cortex_a8_relocs_info_[address] =
12018         new Cortex_a8_reloc(stub, r_type,
12019                             destination | (target_is_thumb ? 1 : 0));
12020     }
12021 }
12022
12023 // This function scans a relocation sections for stub generation.
12024 // The template parameter Relocate must be a class type which provides
12025 // a single function, relocate(), which implements the machine
12026 // specific part of a relocation.
12027
12028 // BIG_ENDIAN is the endianness of the data.  SH_TYPE is the section type:
12029 // SHT_REL or SHT_RELA.
12030
12031 // PRELOCS points to the relocation data.  RELOC_COUNT is the number
12032 // of relocs.  OUTPUT_SECTION is the output section.
12033 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
12034 // mapped to output offsets.
12035
12036 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
12037 // VIEW_SIZE is the size.  These refer to the input section, unless
12038 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
12039 // the output section.
12040
12041 template<bool big_endian>
12042 template<int sh_type>
12043 void inline
12044 Target_arm<big_endian>::scan_reloc_section_for_stubs(
12045     const Relocate_info<32, big_endian>* relinfo,
12046     const unsigned char* prelocs,
12047     size_t reloc_count,
12048     Output_section* output_section,
12049     bool needs_special_offset_handling,
12050     const unsigned char* view,
12051     elfcpp::Elf_types<32>::Elf_Addr view_address,
12052     section_size_type)
12053 {
12054   typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
12055   const int reloc_size =
12056     Reloc_types<sh_type, 32, big_endian>::reloc_size;
12057
12058   Arm_relobj<big_endian>* arm_object =
12059     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
12060   unsigned int local_count = arm_object->local_symbol_count();
12061
12062   gold::Default_comdat_behavior default_comdat_behavior;
12063   Comdat_behavior comdat_behavior = CB_UNDETERMINED;
12064
12065   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
12066     {
12067       Reltype reloc(prelocs);
12068
12069       typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
12070       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
12071       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
12072
12073       r_type = this->get_real_reloc_type(r_type);
12074
12075       // Only a few relocation types need stubs.
12076       if ((r_type != elfcpp::R_ARM_CALL)
12077          && (r_type != elfcpp::R_ARM_JUMP24)
12078          && (r_type != elfcpp::R_ARM_PLT32)
12079          && (r_type != elfcpp::R_ARM_THM_CALL)
12080          && (r_type != elfcpp::R_ARM_THM_XPC22)
12081          && (r_type != elfcpp::R_ARM_THM_JUMP24)
12082          && (r_type != elfcpp::R_ARM_THM_JUMP19)
12083          && (r_type != elfcpp::R_ARM_V4BX))
12084         continue;
12085
12086       section_offset_type offset =
12087         convert_to_section_size_type(reloc.get_r_offset());
12088
12089       if (needs_special_offset_handling)
12090         {
12091           offset = output_section->output_offset(relinfo->object,
12092                                                  relinfo->data_shndx,
12093                                                  offset);
12094           if (offset == -1)
12095             continue;
12096         }
12097
12098       // Create a v4bx stub if --fix-v4bx-interworking is used.
12099       if (r_type == elfcpp::R_ARM_V4BX)
12100         {
12101           if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
12102             {
12103               // Get the BX instruction.
12104               typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
12105               const Valtype* wv =
12106                 reinterpret_cast<const Valtype*>(view + offset);
12107               elfcpp::Elf_types<32>::Elf_Swxword insn =
12108                 elfcpp::Swap<32, big_endian>::readval(wv);
12109               const uint32_t reg = (insn & 0xf);
12110
12111               if (reg < 0xf)
12112                 {
12113                   // Try looking up an existing stub from a stub table.
12114                   Stub_table<big_endian>* stub_table =
12115                     arm_object->stub_table(relinfo->data_shndx);
12116                   gold_assert(stub_table != NULL);
12117
12118                   if (stub_table->find_arm_v4bx_stub(reg) == NULL)
12119                     {
12120                       // create a new stub and add it to stub table.
12121                       Arm_v4bx_stub* stub =
12122                         this->stub_factory().make_arm_v4bx_stub(reg);
12123                       gold_assert(stub != NULL);
12124                       stub_table->add_arm_v4bx_stub(stub);
12125                     }
12126                 }
12127             }
12128           continue;
12129         }
12130
12131       // Get the addend.
12132       Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
12133       elfcpp::Elf_types<32>::Elf_Swxword addend =
12134         stub_addend_reader(r_type, view + offset, reloc);
12135
12136       const Sized_symbol<32>* sym;
12137
12138       Symbol_value<32> symval;
12139       const Symbol_value<32> *psymval;
12140       bool is_defined_in_discarded_section;
12141       unsigned int shndx;
12142       if (r_sym < local_count)
12143         {
12144           sym = NULL;
12145           psymval = arm_object->local_symbol(r_sym);
12146
12147           // If the local symbol belongs to a section we are discarding,
12148           // and that section is a debug section, try to find the
12149           // corresponding kept section and map this symbol to its
12150           // counterpart in the kept section.  The symbol must not
12151           // correspond to a section we are folding.
12152           bool is_ordinary;
12153           shndx = psymval->input_shndx(&is_ordinary);
12154           is_defined_in_discarded_section =
12155             (is_ordinary
12156              && shndx != elfcpp::SHN_UNDEF
12157              && !arm_object->is_section_included(shndx)
12158              && !relinfo->symtab->is_section_folded(arm_object, shndx));
12159
12160           // We need to compute the would-be final value of this local
12161           // symbol.
12162           if (!is_defined_in_discarded_section)
12163             {
12164               typedef Sized_relobj_file<32, big_endian> ObjType;
12165               if (psymval->is_section_symbol())
12166                 symval.set_is_section_symbol();
12167               typename ObjType::Compute_final_local_value_status status =
12168                 arm_object->compute_final_local_value(r_sym, psymval, &symval,
12169                                                       relinfo->symtab);
12170               if (status == ObjType::CFLV_OK)
12171                 {
12172                   // Currently we cannot handle a branch to a target in
12173                   // a merged section.  If this is the case, issue an error
12174                   // and also free the merge symbol value.
12175                   if (!symval.has_output_value())
12176                     {
12177                       const std::string& section_name =
12178                         arm_object->section_name(shndx);
12179                       arm_object->error(_("cannot handle branch to local %u "
12180                                           "in a merged section %s"),
12181                                         r_sym, section_name.c_str());
12182                     }
12183                   psymval = &symval;
12184                 }
12185               else
12186                 {
12187                   // We cannot determine the final value.
12188                   continue;
12189                 }
12190             }
12191         }
12192       else
12193         {
12194           const Symbol* gsym;
12195           gsym = arm_object->global_symbol(r_sym);
12196           gold_assert(gsym != NULL);
12197           if (gsym->is_forwarder())
12198             gsym = relinfo->symtab->resolve_forwards(gsym);
12199
12200           sym = static_cast<const Sized_symbol<32>*>(gsym);
12201           if (sym->has_symtab_index() && sym->symtab_index() != -1U)
12202             symval.set_output_symtab_index(sym->symtab_index());
12203           else
12204             symval.set_no_output_symtab_entry();
12205
12206           // We need to compute the would-be final value of this global
12207           // symbol.
12208           const Symbol_table* symtab = relinfo->symtab;
12209           const Sized_symbol<32>* sized_symbol =
12210             symtab->get_sized_symbol<32>(gsym);
12211           Symbol_table::Compute_final_value_status status;
12212           Arm_address value =
12213             symtab->compute_final_value<32>(sized_symbol, &status);
12214
12215           // Skip this if the symbol has not output section.
12216           if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
12217             continue;
12218           symval.set_output_value(value);
12219
12220           if (gsym->type() == elfcpp::STT_TLS)
12221             symval.set_is_tls_symbol();
12222           else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
12223             symval.set_is_ifunc_symbol();
12224           psymval = &symval;
12225
12226           is_defined_in_discarded_section =
12227             (gsym->is_defined_in_discarded_section()
12228              && gsym->is_undefined());
12229           shndx = 0;
12230         }
12231
12232       Symbol_value<32> symval2;
12233       if (is_defined_in_discarded_section)
12234         {
12235           if (comdat_behavior == CB_UNDETERMINED)
12236             {
12237               std::string name = arm_object->section_name(relinfo->data_shndx);
12238               comdat_behavior = default_comdat_behavior.get(name.c_str());
12239             }
12240           if (comdat_behavior == CB_PRETEND)
12241             {
12242               // FIXME: This case does not work for global symbols.
12243               // We have no place to store the original section index.
12244               // Fortunately this does not matter for comdat sections,
12245               // only for sections explicitly discarded by a linker
12246               // script.
12247               bool found;
12248               typename elfcpp::Elf_types<32>::Elf_Addr value =
12249                 arm_object->map_to_kept_section(shndx, &found);
12250               if (found)
12251                 symval2.set_output_value(value + psymval->input_value());
12252               else
12253                 symval2.set_output_value(0);
12254             }
12255           else
12256             {
12257               if (comdat_behavior == CB_WARNING)
12258                 gold_warning_at_location(relinfo, i, offset,
12259                                          _("relocation refers to discarded "
12260                                            "section"));
12261               symval2.set_output_value(0);
12262             }
12263           symval2.set_no_output_symtab_entry();
12264           psymval = &symval2;
12265         }
12266
12267       // If symbol is a section symbol, we don't know the actual type of
12268       // destination.  Give up.
12269       if (psymval->is_section_symbol())
12270         continue;
12271
12272       this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
12273                                 addend, view_address + offset);
12274     }
12275 }
12276
12277 // Scan an input section for stub generation.
12278
12279 template<bool big_endian>
12280 void
12281 Target_arm<big_endian>::scan_section_for_stubs(
12282     const Relocate_info<32, big_endian>* relinfo,
12283     unsigned int sh_type,
12284     const unsigned char* prelocs,
12285     size_t reloc_count,
12286     Output_section* output_section,
12287     bool needs_special_offset_handling,
12288     const unsigned char* view,
12289     Arm_address view_address,
12290     section_size_type view_size)
12291 {
12292   if (sh_type == elfcpp::SHT_REL)
12293     this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
12294         relinfo,
12295         prelocs,
12296         reloc_count,
12297         output_section,
12298         needs_special_offset_handling,
12299         view,
12300         view_address,
12301         view_size);
12302   else if (sh_type == elfcpp::SHT_RELA)
12303     // We do not support RELA type relocations yet.  This is provided for
12304     // completeness.
12305     this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
12306         relinfo,
12307         prelocs,
12308         reloc_count,
12309         output_section,
12310         needs_special_offset_handling,
12311         view,
12312         view_address,
12313         view_size);
12314   else
12315     gold_unreachable();
12316 }
12317
12318 // Group input sections for stub generation.
12319 //
12320 // We group input sections in an output section so that the total size,
12321 // including any padding space due to alignment is smaller than GROUP_SIZE
12322 // unless the only input section in group is bigger than GROUP_SIZE already.
12323 // Then an ARM stub table is created to follow the last input section
12324 // in group.  For each group an ARM stub table is created an is placed
12325 // after the last group.  If STUB_ALWAYS_AFTER_BRANCH is false, we further
12326 // extend the group after the stub table.
12327
12328 template<bool big_endian>
12329 void
12330 Target_arm<big_endian>::group_sections(
12331     Layout* layout,
12332     section_size_type group_size,
12333     bool stubs_always_after_branch,
12334     const Task* task)
12335 {
12336   // Group input sections and insert stub table
12337   Layout::Section_list section_list;
12338   layout->get_executable_sections(&section_list);
12339   for (Layout::Section_list::const_iterator p = section_list.begin();
12340        p != section_list.end();
12341        ++p)
12342     {
12343       Arm_output_section<big_endian>* output_section =
12344         Arm_output_section<big_endian>::as_arm_output_section(*p);
12345       output_section->group_sections(group_size, stubs_always_after_branch,
12346                                      this, task);
12347     }
12348 }
12349
12350 // Relaxation hook.  This is where we do stub generation.
12351
12352 template<bool big_endian>
12353 bool
12354 Target_arm<big_endian>::do_relax(
12355     int pass,
12356     const Input_objects* input_objects,
12357     Symbol_table* symtab,
12358     Layout* layout,
12359     const Task* task)
12360 {
12361   // No need to generate stubs if this is a relocatable link.
12362   gold_assert(!parameters->options().relocatable());
12363
12364   // If this is the first pass, we need to group input sections into
12365   // stub groups.
12366   bool done_exidx_fixup = false;
12367   typedef typename Stub_table_list::iterator Stub_table_iterator;
12368   if (pass == 1)
12369     {
12370       // Determine the stub group size.  The group size is the absolute
12371       // value of the parameter --stub-group-size.  If --stub-group-size
12372       // is passed a negative value, we restrict stubs to be always after
12373       // the stubbed branches.
12374       int32_t stub_group_size_param =
12375         parameters->options().stub_group_size();
12376       bool stubs_always_after_branch = stub_group_size_param < 0;
12377       section_size_type stub_group_size = abs(stub_group_size_param);
12378
12379       if (stub_group_size == 1)
12380         {
12381           // Default value.
12382           // Thumb branch range is +-4MB has to be used as the default
12383           // maximum size (a given section can contain both ARM and Thumb
12384           // code, so the worst case has to be taken into account).  If we are
12385           // fixing cortex-a8 errata, the branch range has to be even smaller,
12386           // since wide conditional branch has a range of +-1MB only.
12387           //
12388           // This value is 48K less than that, which allows for 4096
12389           // 12-byte stubs.  If we exceed that, then we will fail to link.
12390           // The user will have to relink with an explicit group size
12391           // option.
12392             stub_group_size = 4145152;
12393         }
12394
12395       // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
12396       // page as the first half of a 32-bit branch straddling two 4K pages.
12397       // This is a crude way of enforcing that.  In addition, long conditional
12398       // branches of THUMB-2 have a range of +-1M.  If we are fixing cortex-A8
12399       // erratum, limit the group size to  (1M - 12k) to avoid unreachable
12400       // cortex-A8 stubs from long conditional branches.
12401       if (this->fix_cortex_a8_)
12402         {
12403           stubs_always_after_branch = true;
12404           const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
12405           stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
12406         }
12407
12408       group_sections(layout, stub_group_size, stubs_always_after_branch, task);
12409
12410       // Also fix .ARM.exidx section coverage.
12411       Arm_output_section<big_endian>* exidx_output_section = NULL;
12412       for (Layout::Section_list::const_iterator p =
12413              layout->section_list().begin();
12414            p != layout->section_list().end();
12415            ++p)
12416         if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
12417           {
12418             if (exidx_output_section == NULL)
12419               exidx_output_section =
12420                 Arm_output_section<big_endian>::as_arm_output_section(*p);
12421             else
12422               // We cannot handle this now.
12423               gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
12424                            "non-relocatable link"),
12425                           exidx_output_section->name(),
12426                           (*p)->name());
12427           }
12428
12429       if (exidx_output_section != NULL)
12430         {
12431           this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
12432                                    symtab, task);
12433           done_exidx_fixup = true;
12434         }
12435     }
12436   else
12437     {
12438       // If this is not the first pass, addresses and file offsets have
12439       // been reset at this point, set them here.
12440       for (Stub_table_iterator sp = this->stub_tables_.begin();
12441            sp != this->stub_tables_.end();
12442            ++sp)
12443         {
12444           Arm_input_section<big_endian>* owner = (*sp)->owner();
12445           off_t off = align_address(owner->original_size(),
12446                                     (*sp)->addralign());
12447           (*sp)->set_address_and_file_offset(owner->address() + off,
12448                                              owner->offset() + off);
12449         }
12450     }
12451
12452   // The Cortex-A8 stubs are sensitive to layout of code sections.  At the
12453   // beginning of each relaxation pass, just blow away all the stubs.
12454   // Alternatively, we could selectively remove only the stubs and reloc
12455   // information for code sections that have moved since the last pass.
12456   // That would require more book-keeping.
12457   if (this->fix_cortex_a8_)
12458     {
12459       // Clear all Cortex-A8 reloc information.
12460       for (typename Cortex_a8_relocs_info::const_iterator p =
12461              this->cortex_a8_relocs_info_.begin();
12462            p != this->cortex_a8_relocs_info_.end();
12463            ++p)
12464         delete p->second;
12465       this->cortex_a8_relocs_info_.clear();
12466
12467       // Remove all Cortex-A8 stubs.
12468       for (Stub_table_iterator sp = this->stub_tables_.begin();
12469            sp != this->stub_tables_.end();
12470            ++sp)
12471         (*sp)->remove_all_cortex_a8_stubs();
12472     }
12473
12474   // Scan relocs for relocation stubs
12475   for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
12476        op != input_objects->relobj_end();
12477        ++op)
12478     {
12479       Arm_relobj<big_endian>* arm_relobj =
12480         Arm_relobj<big_endian>::as_arm_relobj(*op);
12481       // Lock the object so we can read from it.  This is only called
12482       // single-threaded from Layout::finalize, so it is OK to lock.
12483       Task_lock_obj<Object> tl(task, arm_relobj);
12484       arm_relobj->scan_sections_for_stubs(this, symtab, layout);
12485     }
12486
12487   // Check all stub tables to see if any of them have their data sizes
12488   // or addresses alignments changed.  These are the only things that
12489   // matter.
12490   bool any_stub_table_changed = false;
12491   Unordered_set<const Output_section*> sections_needing_adjustment;
12492   for (Stub_table_iterator sp = this->stub_tables_.begin();
12493        (sp != this->stub_tables_.end()) && !any_stub_table_changed;
12494        ++sp)
12495     {
12496       if ((*sp)->update_data_size_and_addralign())
12497         {
12498           // Update data size of stub table owner.
12499           Arm_input_section<big_endian>* owner = (*sp)->owner();
12500           uint64_t address = owner->address();
12501           off_t offset = owner->offset();
12502           owner->reset_address_and_file_offset();
12503           owner->set_address_and_file_offset(address, offset);
12504
12505           sections_needing_adjustment.insert(owner->output_section());
12506           any_stub_table_changed = true;
12507         }
12508     }
12509
12510   // Output_section_data::output_section() returns a const pointer but we
12511   // need to update output sections, so we record all output sections needing
12512   // update above and scan the sections here to find out what sections need
12513   // to be updated.
12514   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
12515       p != layout->section_list().end();
12516       ++p)
12517     {
12518       if (sections_needing_adjustment.find(*p)
12519           != sections_needing_adjustment.end())
12520         (*p)->set_section_offsets_need_adjustment();
12521     }
12522
12523   // Stop relaxation if no EXIDX fix-up and no stub table change.
12524   bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
12525
12526   // Finalize the stubs in the last relaxation pass.
12527   if (!continue_relaxation)
12528     {
12529       for (Stub_table_iterator sp = this->stub_tables_.begin();
12530            (sp != this->stub_tables_.end()) && !any_stub_table_changed;
12531             ++sp)
12532         (*sp)->finalize_stubs();
12533
12534       // Update output local symbol counts of objects if necessary.
12535       for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
12536            op != input_objects->relobj_end();
12537            ++op)
12538         {
12539           Arm_relobj<big_endian>* arm_relobj =
12540             Arm_relobj<big_endian>::as_arm_relobj(*op);
12541
12542           // Update output local symbol counts.  We need to discard local
12543           // symbols defined in parts of input sections that are discarded by
12544           // relaxation.
12545           if (arm_relobj->output_local_symbol_count_needs_update())
12546             {
12547               // We need to lock the object's file to update it.
12548               Task_lock_obj<Object> tl(task, arm_relobj);
12549               arm_relobj->update_output_local_symbol_count();
12550             }
12551         }
12552     }
12553
12554   return continue_relaxation;
12555 }
12556
12557 // Relocate a stub.
12558
12559 template<bool big_endian>
12560 void
12561 Target_arm<big_endian>::relocate_stub(
12562     Stub* stub,
12563     const Relocate_info<32, big_endian>* relinfo,
12564     Output_section* output_section,
12565     unsigned char* view,
12566     Arm_address address,
12567     section_size_type view_size)
12568 {
12569   Relocate relocate;
12570   const Stub_template* stub_template = stub->stub_template();
12571   for (size_t i = 0; i < stub_template->reloc_count(); i++)
12572     {
12573       size_t reloc_insn_index = stub_template->reloc_insn_index(i);
12574       const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
12575
12576       unsigned int r_type = insn->r_type();
12577       section_size_type reloc_offset = stub_template->reloc_offset(i);
12578       section_size_type reloc_size = insn->size();
12579       gold_assert(reloc_offset + reloc_size <= view_size);
12580
12581       // This is the address of the stub destination.
12582       Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
12583       Symbol_value<32> symval;
12584       symval.set_output_value(target);
12585
12586       // Synthesize a fake reloc just in case.  We don't have a symbol so
12587       // we use 0.
12588       unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
12589       memset(reloc_buffer, 0, sizeof(reloc_buffer));
12590       elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
12591       reloc_write.put_r_offset(reloc_offset);
12592       reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
12593
12594       relocate.relocate(relinfo, elfcpp::SHT_REL, this, output_section,
12595                         this->fake_relnum_for_stubs, reloc_buffer,
12596                         NULL, &symval, view + reloc_offset,
12597                         address + reloc_offset, reloc_size);
12598     }
12599 }
12600
12601 // Determine whether an object attribute tag takes an integer, a
12602 // string or both.
12603
12604 template<bool big_endian>
12605 int
12606 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
12607 {
12608   if (tag == Object_attribute::Tag_compatibility)
12609     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
12610             | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
12611   else if (tag == elfcpp::Tag_nodefaults)
12612     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
12613             | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
12614   else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
12615     return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
12616   else if (tag < 32)
12617     return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
12618   else
12619     return ((tag & 1) != 0
12620             ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
12621             : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
12622 }
12623
12624 // Reorder attributes.
12625 //
12626 // The ABI defines that Tag_conformance should be emitted first, and that
12627 // Tag_nodefaults should be second (if either is defined).  This sets those
12628 // two positions, and bumps up the position of all the remaining tags to
12629 // compensate.
12630
12631 template<bool big_endian>
12632 int
12633 Target_arm<big_endian>::do_attributes_order(int num) const
12634 {
12635   // Reorder the known object attributes in output.  We want to move
12636   // Tag_conformance to position 4 and Tag_conformance to position 5
12637   // and shift everything between 4 .. Tag_conformance - 1 to make room.
12638   if (num == 4)
12639     return elfcpp::Tag_conformance;
12640   if (num == 5)
12641     return elfcpp::Tag_nodefaults;
12642   if ((num - 2) < elfcpp::Tag_nodefaults)
12643     return num - 2;
12644   if ((num - 1) < elfcpp::Tag_conformance)
12645     return num - 1;
12646   return num;
12647 }
12648
12649 // Scan a span of THUMB code for Cortex-A8 erratum.
12650
12651 template<bool big_endian>
12652 void
12653 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
12654     Arm_relobj<big_endian>* arm_relobj,
12655     unsigned int shndx,
12656     section_size_type span_start,
12657     section_size_type span_end,
12658     const unsigned char* view,
12659     Arm_address address)
12660 {
12661   // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
12662   //
12663   // The opcode is BLX.W, BL.W, B.W, Bcc.W
12664   // The branch target is in the same 4KB region as the
12665   // first half of the branch.
12666   // The instruction before the branch is a 32-bit
12667   // length non-branch instruction.
12668   section_size_type i = span_start;
12669   bool last_was_32bit = false;
12670   bool last_was_branch = false;
12671   while (i < span_end)
12672     {
12673       typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
12674       const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
12675       uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
12676       bool is_blx = false, is_b = false;
12677       bool is_bl = false, is_bcc = false;
12678
12679       bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
12680       if (insn_32bit)
12681         {
12682           // Load the rest of the insn (in manual-friendly order).
12683           insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
12684
12685           // Encoding T4: B<c>.W.
12686           is_b = (insn & 0xf800d000U) == 0xf0009000U;
12687           // Encoding T1: BL<c>.W.
12688           is_bl = (insn & 0xf800d000U) == 0xf000d000U;
12689           // Encoding T2: BLX<c>.W.
12690           is_blx = (insn & 0xf800d000U) == 0xf000c000U;
12691           // Encoding T3: B<c>.W (not permitted in IT block).
12692           is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
12693                     && (insn & 0x07f00000U) != 0x03800000U);
12694         }
12695
12696       bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
12697
12698       // If this instruction is a 32-bit THUMB branch that crosses a 4K
12699       // page boundary and it follows 32-bit non-branch instruction,
12700       // we need to work around.
12701       if (is_32bit_branch
12702           && ((address + i) & 0xfffU) == 0xffeU
12703           && last_was_32bit
12704           && !last_was_branch)
12705         {
12706           // Check to see if there is a relocation stub for this branch.
12707           bool force_target_arm = false;
12708           bool force_target_thumb = false;
12709           const Cortex_a8_reloc* cortex_a8_reloc = NULL;
12710           Cortex_a8_relocs_info::const_iterator p =
12711             this->cortex_a8_relocs_info_.find(address + i);
12712
12713           if (p != this->cortex_a8_relocs_info_.end())
12714             {
12715               cortex_a8_reloc = p->second;
12716               bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
12717
12718               if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
12719                   && !target_is_thumb)
12720                 force_target_arm = true;
12721               else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
12722                        && target_is_thumb)
12723                 force_target_thumb = true;
12724             }
12725
12726           off_t offset;
12727           Stub_type stub_type = arm_stub_none;
12728
12729           // Check if we have an offending branch instruction.
12730           uint16_t upper_insn = (insn >> 16) & 0xffffU;
12731           uint16_t lower_insn = insn & 0xffffU;
12732           typedef class Arm_relocate_functions<big_endian> RelocFuncs;
12733
12734           if (cortex_a8_reloc != NULL
12735               && cortex_a8_reloc->reloc_stub() != NULL)
12736             // We've already made a stub for this instruction, e.g.
12737             // it's a long branch or a Thumb->ARM stub.  Assume that
12738             // stub will suffice to work around the A8 erratum (see
12739             // setting of always_after_branch above).
12740             ;
12741           else if (is_bcc)
12742             {
12743               offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
12744                                                               lower_insn);
12745               stub_type = arm_stub_a8_veneer_b_cond;
12746             }
12747           else if (is_b || is_bl || is_blx)
12748             {
12749               offset = RelocFuncs::thumb32_branch_offset(upper_insn,
12750                                                          lower_insn);
12751               if (is_blx)
12752                 offset &= ~3;
12753
12754               stub_type = (is_blx
12755                            ? arm_stub_a8_veneer_blx
12756                            : (is_bl
12757                               ? arm_stub_a8_veneer_bl
12758                               : arm_stub_a8_veneer_b));
12759             }
12760
12761           if (stub_type != arm_stub_none)
12762             {
12763               Arm_address pc_for_insn = address + i + 4;
12764
12765               // The original instruction is a BL, but the target is
12766               // an ARM instruction.  If we were not making a stub,
12767               // the BL would have been converted to a BLX.  Use the
12768               // BLX stub instead in that case.
12769               if (this->may_use_v5t_interworking() && force_target_arm
12770                   && stub_type == arm_stub_a8_veneer_bl)
12771                 {
12772                   stub_type = arm_stub_a8_veneer_blx;
12773                   is_blx = true;
12774                   is_bl = false;
12775                 }
12776               // Conversely, if the original instruction was
12777               // BLX but the target is Thumb mode, use the BL stub.
12778               else if (force_target_thumb
12779                        && stub_type == arm_stub_a8_veneer_blx)
12780                 {
12781                   stub_type = arm_stub_a8_veneer_bl;
12782                   is_blx = false;
12783                   is_bl = true;
12784                 }
12785
12786               if (is_blx)
12787                 pc_for_insn &= ~3;
12788
12789               // If we found a relocation, use the proper destination,
12790               // not the offset in the (unrelocated) instruction.
12791               // Note this is always done if we switched the stub type above.
12792               if (cortex_a8_reloc != NULL)
12793                 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
12794
12795               Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
12796
12797               // Add a new stub if destination address is in the same page.
12798               if (((address + i) & ~0xfffU) == (target & ~0xfffU))
12799                 {
12800                   Cortex_a8_stub* stub =
12801                     this->stub_factory_.make_cortex_a8_stub(stub_type,
12802                                                             arm_relobj, shndx,
12803                                                             address + i,
12804                                                             target, insn);
12805                   Stub_table<big_endian>* stub_table =
12806                     arm_relobj->stub_table(shndx);
12807                   gold_assert(stub_table != NULL);
12808                   stub_table->add_cortex_a8_stub(address + i, stub);
12809                 }
12810             }
12811         }
12812
12813       i += insn_32bit ? 4 : 2;
12814       last_was_32bit = insn_32bit;
12815       last_was_branch = is_32bit_branch;
12816     }
12817 }
12818
12819 // Apply the Cortex-A8 workaround.
12820
12821 template<bool big_endian>
12822 void
12823 Target_arm<big_endian>::apply_cortex_a8_workaround(
12824     const Cortex_a8_stub* stub,
12825     Arm_address stub_address,
12826     unsigned char* insn_view,
12827     Arm_address insn_address)
12828 {
12829   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
12830   Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
12831   Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
12832   Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
12833   off_t branch_offset = stub_address - (insn_address + 4);
12834
12835   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
12836   switch (stub->stub_template()->type())
12837     {
12838     case arm_stub_a8_veneer_b_cond:
12839       // For a conditional branch, we re-write it to be an unconditional
12840       // branch to the stub.  We use the THUMB-2 encoding here.
12841       upper_insn = 0xf000U;
12842       lower_insn = 0xb800U;
12843       // Fall through.
12844     case arm_stub_a8_veneer_b:
12845     case arm_stub_a8_veneer_bl:
12846     case arm_stub_a8_veneer_blx:
12847       if ((lower_insn & 0x5000U) == 0x4000U)
12848         // For a BLX instruction, make sure that the relocation is
12849         // rounded up to a word boundary.  This follows the semantics of
12850         // the instruction which specifies that bit 1 of the target
12851         // address will come from bit 1 of the base address.
12852         branch_offset = (branch_offset + 2) & ~3;
12853
12854       // Put BRANCH_OFFSET back into the insn.
12855       gold_assert(!Bits<25>::has_overflow32(branch_offset));
12856       upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
12857       lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
12858       break;
12859
12860     default:
12861       gold_unreachable();
12862     }
12863
12864   // Put the relocated value back in the object file:
12865   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
12866   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
12867 }
12868
12869 // Target selector for ARM.  Note this is never instantiated directly.
12870 // It's only used in Target_selector_arm_nacl, below.
12871
12872 template<bool big_endian>
12873 class Target_selector_arm : public Target_selector
12874 {
12875  public:
12876   Target_selector_arm()
12877     : Target_selector(elfcpp::EM_ARM, 32, big_endian,
12878                       (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
12879                       (big_endian ? "armelfb" : "armelf"))
12880   { }
12881
12882   Target*
12883   do_instantiate_target()
12884   { return new Target_arm<big_endian>(); }
12885 };
12886
12887 // Fix .ARM.exidx section coverage.
12888
12889 template<bool big_endian>
12890 void
12891 Target_arm<big_endian>::fix_exidx_coverage(
12892     Layout* layout,
12893     const Input_objects* input_objects,
12894     Arm_output_section<big_endian>* exidx_section,
12895     Symbol_table* symtab,
12896     const Task* task)
12897 {
12898   // We need to look at all the input sections in output in ascending
12899   // order of output address.  We do that by building a sorted list
12900   // of output sections by addresses.  Then we looks at the output sections
12901   // in order.  The input sections in an output section are already sorted
12902   // by addresses within the output section.
12903
12904   typedef std::set<Output_section*, output_section_address_less_than>
12905       Sorted_output_section_list;
12906   Sorted_output_section_list sorted_output_sections;
12907
12908   // Find out all the output sections of input sections pointed by
12909   // EXIDX input sections.
12910   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
12911        p != input_objects->relobj_end();
12912        ++p)
12913     {
12914       Arm_relobj<big_endian>* arm_relobj =
12915         Arm_relobj<big_endian>::as_arm_relobj(*p);
12916       std::vector<unsigned int> shndx_list;
12917       arm_relobj->get_exidx_shndx_list(&shndx_list);
12918       for (size_t i = 0; i < shndx_list.size(); ++i)
12919         {
12920           const Arm_exidx_input_section* exidx_input_section =
12921             arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
12922           gold_assert(exidx_input_section != NULL);
12923           if (!exidx_input_section->has_errors())
12924             {
12925               unsigned int text_shndx = exidx_input_section->link();
12926               Output_section* os = arm_relobj->output_section(text_shndx);
12927               if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
12928                 sorted_output_sections.insert(os);
12929             }
12930         }
12931     }
12932
12933   // Go over the output sections in ascending order of output addresses.
12934   typedef typename Arm_output_section<big_endian>::Text_section_list
12935       Text_section_list;
12936   Text_section_list sorted_text_sections;
12937   for (typename Sorted_output_section_list::iterator p =
12938         sorted_output_sections.begin();
12939       p != sorted_output_sections.end();
12940       ++p)
12941     {
12942       Arm_output_section<big_endian>* arm_output_section =
12943         Arm_output_section<big_endian>::as_arm_output_section(*p);
12944       arm_output_section->append_text_sections_to_list(&sorted_text_sections);
12945     }
12946
12947   exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
12948                                     merge_exidx_entries(), task);
12949 }
12950
12951 template<bool big_endian>
12952 void
12953 Target_arm<big_endian>::do_define_standard_symbols(
12954     Symbol_table* symtab,
12955     Layout* layout)
12956 {
12957   // Handle the .ARM.exidx section.
12958   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
12959
12960   if (exidx_section != NULL)
12961     {
12962       // Create __exidx_start and __exidx_end symbols.
12963       symtab->define_in_output_data("__exidx_start",
12964                                     NULL, // version
12965                                     Symbol_table::PREDEFINED,
12966                                     exidx_section,
12967                                     0, // value
12968                                     0, // symsize
12969                                     elfcpp::STT_NOTYPE,
12970                                     elfcpp::STB_GLOBAL,
12971                                     elfcpp::STV_HIDDEN,
12972                                     0, // nonvis
12973                                     false, // offset_is_from_end
12974                                     true); // only_if_ref
12975
12976       symtab->define_in_output_data("__exidx_end",
12977                                     NULL, // version
12978                                     Symbol_table::PREDEFINED,
12979                                     exidx_section,
12980                                     0, // value
12981                                     0, // symsize
12982                                     elfcpp::STT_NOTYPE,
12983                                     elfcpp::STB_GLOBAL,
12984                                     elfcpp::STV_HIDDEN,
12985                                     0, // nonvis
12986                                     true, // offset_is_from_end
12987                                     true); // only_if_ref
12988     }
12989   else
12990     {
12991       // Define __exidx_start and __exidx_end even when .ARM.exidx
12992       // section is missing to match ld's behaviour.
12993       symtab->define_as_constant("__exidx_start", NULL,
12994                                  Symbol_table::PREDEFINED,
12995                                  0, 0, elfcpp::STT_OBJECT,
12996                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12997                                  true, false);
12998       symtab->define_as_constant("__exidx_end", NULL,
12999                                  Symbol_table::PREDEFINED,
13000                                  0, 0, elfcpp::STT_OBJECT,
13001                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
13002                                  true, false);
13003     }
13004 }
13005
13006 // NaCl variant.  It uses different PLT contents.
13007
13008 template<bool big_endian>
13009 class Output_data_plt_arm_nacl;
13010
13011 template<bool big_endian>
13012 class Target_arm_nacl : public Target_arm<big_endian>
13013 {
13014  public:
13015   Target_arm_nacl()
13016     : Target_arm<big_endian>(&arm_nacl_info)
13017   { }
13018
13019  protected:
13020   virtual Output_data_plt_arm<big_endian>*
13021   do_make_data_plt(
13022                    Layout* layout,
13023                    Arm_output_data_got<big_endian>* got,
13024                    Output_data_space* got_plt,
13025                    Output_data_space* got_irelative)
13026   { return new Output_data_plt_arm_nacl<big_endian>(
13027       layout, got, got_plt, got_irelative); }
13028
13029  private:
13030   static const Target::Target_info arm_nacl_info;
13031 };
13032
13033 template<bool big_endian>
13034 const Target::Target_info Target_arm_nacl<big_endian>::arm_nacl_info =
13035 {
13036   32,                   // size
13037   big_endian,           // is_big_endian
13038   elfcpp::EM_ARM,       // machine_code
13039   false,                // has_make_symbol
13040   false,                // has_resolve
13041   false,                // has_code_fill
13042   true,                 // is_default_stack_executable
13043   false,                // can_icf_inline_merge_sections
13044   '\0',                 // wrap_char
13045   "/lib/ld-nacl-arm.so.1", // dynamic_linker
13046   0x20000,              // default_text_segment_address
13047   0x10000,              // abi_pagesize (overridable by -z max-page-size)
13048   0x10000,              // common_pagesize (overridable by -z common-page-size)
13049   true,                 // isolate_execinstr
13050   0x10000000,           // rosegment_gap
13051   elfcpp::SHN_UNDEF,    // small_common_shndx
13052   elfcpp::SHN_UNDEF,    // large_common_shndx
13053   0,                    // small_common_section_flags
13054   0,                    // large_common_section_flags
13055   ".ARM.attributes",    // attributes_section
13056   "aeabi",              // attributes_vendor
13057   "_start",             // entry_symbol_name
13058   32,                   // hash_entry_size
13059 };
13060
13061 template<bool big_endian>
13062 class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
13063 {
13064  public:
13065   Output_data_plt_arm_nacl(
13066       Layout* layout,
13067       Arm_output_data_got<big_endian>* got,
13068       Output_data_space* got_plt,
13069       Output_data_space* got_irelative)
13070     : Output_data_plt_arm<big_endian>(layout, 16, got, got_plt, got_irelative)
13071   { }
13072
13073  protected:
13074   // Return the offset of the first non-reserved PLT entry.
13075   virtual unsigned int
13076   do_first_plt_entry_offset() const
13077   { return sizeof(first_plt_entry); }
13078
13079   // Return the size of a PLT entry.
13080   virtual unsigned int
13081   do_get_plt_entry_size() const
13082   { return sizeof(plt_entry); }
13083
13084   virtual void
13085   do_fill_first_plt_entry(unsigned char* pov,
13086                           Arm_address got_address,
13087                           Arm_address plt_address);
13088
13089   virtual void
13090   do_fill_plt_entry(unsigned char* pov,
13091                     Arm_address got_address,
13092                     Arm_address plt_address,
13093                     unsigned int got_offset,
13094                     unsigned int plt_offset);
13095
13096  private:
13097   inline uint32_t arm_movw_immediate(uint32_t value)
13098   {
13099     return (value & 0x00000fff) | ((value & 0x0000f000) << 4);
13100   }
13101
13102   inline uint32_t arm_movt_immediate(uint32_t value)
13103   {
13104     return ((value & 0x0fff0000) >> 16) | ((value & 0xf0000000) >> 12);
13105   }
13106
13107   // Template for the first PLT entry.
13108   static const uint32_t first_plt_entry[16];
13109
13110   // Template for subsequent PLT entries.
13111   static const uint32_t plt_entry[4];
13112 };
13113
13114 // The first entry in the PLT.
13115 template<bool big_endian>
13116 const uint32_t Output_data_plt_arm_nacl<big_endian>::first_plt_entry[16] =
13117 {
13118   // First bundle:
13119   0xe300c000,                           // movw ip, #:lower16:&GOT[2]-.+8
13120   0xe340c000,                           // movt ip, #:upper16:&GOT[2]-.+8
13121   0xe08cc00f,                           // add  ip, ip, pc
13122   0xe52dc008,                           // str  ip, [sp, #-8]!
13123   // Second bundle:
13124   0xe3ccc103,                           // bic  ip, ip, #0xc0000000
13125   0xe59cc000,                           // ldr  ip, [ip]
13126   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
13127   0xe12fff1c,                           // bx   ip
13128   // Third bundle:
13129   0xe320f000,                           // nop
13130   0xe320f000,                           // nop
13131   0xe320f000,                           // nop
13132   // .Lplt_tail:
13133   0xe50dc004,                           // str  ip, [sp, #-4]
13134   // Fourth bundle:
13135   0xe3ccc103,                           // bic  ip, ip, #0xc0000000
13136   0xe59cc000,                           // ldr  ip, [ip]
13137   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
13138   0xe12fff1c,                           // bx   ip
13139 };
13140
13141 template<bool big_endian>
13142 void
13143 Output_data_plt_arm_nacl<big_endian>::do_fill_first_plt_entry(
13144     unsigned char* pov,
13145     Arm_address got_address,
13146     Arm_address plt_address)
13147 {
13148   // Write first PLT entry.  All but first two words are constants.
13149   const size_t num_first_plt_words = (sizeof(first_plt_entry)
13150                                       / sizeof(first_plt_entry[0]));
13151
13152   int32_t got_displacement = got_address + 8 - (plt_address + 16);
13153
13154   elfcpp::Swap<32, big_endian>::writeval
13155     (pov + 0, first_plt_entry[0] | arm_movw_immediate (got_displacement));
13156   elfcpp::Swap<32, big_endian>::writeval
13157     (pov + 4, first_plt_entry[1] | arm_movt_immediate (got_displacement));
13158
13159   for (size_t i = 2; i < num_first_plt_words; ++i)
13160     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
13161 }
13162
13163 // Subsequent entries in the PLT.
13164
13165 template<bool big_endian>
13166 const uint32_t Output_data_plt_arm_nacl<big_endian>::plt_entry[4] =
13167 {
13168   0xe300c000,                           // movw ip, #:lower16:&GOT[n]-.+8
13169   0xe340c000,                           // movt ip, #:upper16:&GOT[n]-.+8
13170   0xe08cc00f,                           // add  ip, ip, pc
13171   0xea000000,                           // b    .Lplt_tail
13172 };
13173
13174 template<bool big_endian>
13175 void
13176 Output_data_plt_arm_nacl<big_endian>::do_fill_plt_entry(
13177     unsigned char* pov,
13178     Arm_address got_address,
13179     Arm_address plt_address,
13180     unsigned int got_offset,
13181     unsigned int plt_offset)
13182 {
13183   // Calculate the displacement between the PLT slot and the
13184   // common tail that's part of the special initial PLT slot.
13185   int32_t tail_displacement = (plt_address + (11 * sizeof(uint32_t))
13186                                - (plt_address + plt_offset
13187                                   + sizeof(plt_entry) + sizeof(uint32_t)));
13188   gold_assert((tail_displacement & 3) == 0);
13189   tail_displacement >>= 2;
13190
13191   gold_assert ((tail_displacement & 0xff000000) == 0
13192                || (-tail_displacement & 0xff000000) == 0);
13193
13194   // Calculate the displacement between the PLT slot and the entry
13195   // in the GOT.  The offset accounts for the value produced by
13196   // adding to pc in the penultimate instruction of the PLT stub.
13197   const int32_t got_displacement = (got_address + got_offset
13198                                     - (plt_address + sizeof(plt_entry)));
13199
13200   elfcpp::Swap<32, big_endian>::writeval
13201     (pov + 0, plt_entry[0] | arm_movw_immediate (got_displacement));
13202   elfcpp::Swap<32, big_endian>::writeval
13203     (pov + 4, plt_entry[1] | arm_movt_immediate (got_displacement));
13204   elfcpp::Swap<32, big_endian>::writeval
13205     (pov + 8, plt_entry[2]);
13206   elfcpp::Swap<32, big_endian>::writeval
13207     (pov + 12, plt_entry[3] | (tail_displacement & 0x00ffffff));
13208 }
13209
13210 // Target selectors.
13211
13212 template<bool big_endian>
13213 class Target_selector_arm_nacl
13214   : public Target_selector_nacl<Target_selector_arm<big_endian>,
13215                                 Target_arm_nacl<big_endian> >
13216 {
13217  public:
13218   Target_selector_arm_nacl()
13219     : Target_selector_nacl<Target_selector_arm<big_endian>,
13220                            Target_arm_nacl<big_endian> >(
13221           "arm",
13222           big_endian ? "elf32-bigarm-nacl" : "elf32-littlearm-nacl",
13223           big_endian ? "armelfb_nacl" : "armelf_nacl")
13224   { }
13225 };
13226
13227 Target_selector_arm_nacl<false> target_selector_arm;
13228 Target_selector_arm_nacl<true> target_selector_armbe;
13229
13230 } // End anonymous namespace.