2015-07-23 Ian Coolidge <icoolidge@google.com>
[external/binutils.git] / gold / arm.cc
1 // arm.cc -- arm target support for gold.
2
3 // Copyright (C) 2009-2015 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_standard;
66
67 template<bool big_endian>
68 class Stub_table;
69
70 template<bool big_endian>
71 class Arm_input_section;
72
73 class Arm_exidx_cantunwind;
74
75 class Arm_exidx_merged_section;
76
77 class Arm_exidx_fixup;
78
79 template<bool big_endian>
80 class Arm_output_section;
81
82 class Arm_exidx_input_section;
83
84 template<bool big_endian>
85 class Arm_relobj;
86
87 template<bool big_endian>
88 class Arm_relocate_functions;
89
90 template<bool big_endian>
91 class Arm_output_data_got;
92
93 template<bool big_endian>
94 class Target_arm;
95
96 // For convenience.
97 typedef elfcpp::Elf_types<32>::Elf_Addr Arm_address;
98
99 // Maximum branch offsets for ARM, THUMB and THUMB2.
100 const int32_t ARM_MAX_FWD_BRANCH_OFFSET = ((((1 << 23) - 1) << 2) + 8);
101 const int32_t ARM_MAX_BWD_BRANCH_OFFSET = ((-((1 << 23) << 2)) + 8);
102 const int32_t THM_MAX_FWD_BRANCH_OFFSET = ((1 << 22) -2 + 4);
103 const int32_t THM_MAX_BWD_BRANCH_OFFSET = (-(1 << 22) + 4);
104 const int32_t THM2_MAX_FWD_BRANCH_OFFSET = (((1 << 24) - 2) + 4);
105 const int32_t THM2_MAX_BWD_BRANCH_OFFSET = (-(1 << 24) + 4);
106
107 // Thread Control Block size.
108 const size_t ARM_TCB_SIZE = 8;
109
110 // The arm target class.
111 //
112 // This is a very simple port of gold for ARM-EABI.  It is intended for
113 // supporting Android only for the time being.
114 //
115 // TODOs:
116 // - Implement all static relocation types documented in arm-reloc.def.
117 // - Make PLTs more flexible for different architecture features like
118 //   Thumb-2 and BE8.
119 // There are probably a lot more.
120
121 // Ideally we would like to avoid using global variables but this is used
122 // very in many places and sometimes in loops.  If we use a function
123 // returning a static instance of Arm_reloc_property_table, it will be very
124 // slow in an threaded environment since the static instance needs to be
125 // locked.  The pointer is below initialized in the
126 // Target::do_select_as_default_target() hook so that we do not spend time
127 // building the table if we are not linking ARM objects.
128 //
129 // An alternative is to to process the information in arm-reloc.def in
130 // compilation time and generate a representation of it in PODs only.  That
131 // way we can avoid initialization when the linker starts.
132
133 Arm_reloc_property_table* arm_reloc_property_table = NULL;
134
135 // Instruction template class.  This class is similar to the insn_sequence
136 // struct in bfd/elf32-arm.c.
137
138 class Insn_template
139 {
140  public:
141   // Types of instruction templates.
142   enum Type
143     {
144       THUMB16_TYPE = 1,
145       // THUMB16_SPECIAL_TYPE is used by sub-classes of Stub for instruction
146       // templates with class-specific semantics.  Currently this is used
147       // only by the Cortex_a8_stub class for handling condition codes in
148       // conditional branches.
149       THUMB16_SPECIAL_TYPE,
150       THUMB32_TYPE,
151       ARM_TYPE,
152       DATA_TYPE
153     };
154
155   // Factory methods to create instruction templates in different formats.
156
157   static const Insn_template
158   thumb16_insn(uint32_t data)
159   { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 0); }
160
161   // A Thumb conditional branch, in which the proper condition is inserted
162   // when we build the stub.
163   static const Insn_template
164   thumb16_bcond_insn(uint32_t data)
165   { return Insn_template(data, THUMB16_SPECIAL_TYPE, elfcpp::R_ARM_NONE, 1); }
166
167   static const Insn_template
168   thumb32_insn(uint32_t data)
169   { return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_NONE, 0); }
170
171   static const Insn_template
172   thumb32_b_insn(uint32_t data, int reloc_addend)
173   {
174     return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_THM_JUMP24,
175                          reloc_addend);
176   }
177
178   static const Insn_template
179   arm_insn(uint32_t data)
180   { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_NONE, 0); }
181
182   static const Insn_template
183   arm_rel_insn(unsigned data, int reloc_addend)
184   { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_JUMP24, reloc_addend); }
185
186   static const Insn_template
187   data_word(unsigned data, unsigned int r_type, int reloc_addend)
188   { return Insn_template(data, DATA_TYPE, r_type, reloc_addend); }
189
190   // Accessors.  This class is used for read-only objects so no modifiers
191   // are provided.
192
193   uint32_t
194   data() const
195   { return this->data_; }
196
197   // Return the instruction sequence type of this.
198   Type
199   type() const
200   { return this->type_; }
201
202   // Return the ARM relocation type of this.
203   unsigned int
204   r_type() const
205   { return this->r_type_; }
206
207   int32_t
208   reloc_addend() const
209   { return this->reloc_addend_; }
210
211   // Return size of instruction template in bytes.
212   size_t
213   size() const;
214
215   // Return byte-alignment of instruction template.
216   unsigned
217   alignment() const;
218
219  private:
220   // We make the constructor private to ensure that only the factory
221   // methods are used.
222   inline
223   Insn_template(unsigned data, Type type, unsigned int r_type, int reloc_addend)
224     : data_(data), type_(type), r_type_(r_type), reloc_addend_(reloc_addend)
225   { }
226
227   // Instruction specific data.  This is used to store information like
228   // some of the instruction bits.
229   uint32_t data_;
230   // Instruction template type.
231   Type type_;
232   // Relocation type if there is a relocation or R_ARM_NONE otherwise.
233   unsigned int r_type_;
234   // Relocation addend.
235   int32_t reloc_addend_;
236 };
237
238 // Macro for generating code to stub types. One entry per long/short
239 // branch stub
240
241 #define DEF_STUBS \
242   DEF_STUB(long_branch_any_any) \
243   DEF_STUB(long_branch_v4t_arm_thumb) \
244   DEF_STUB(long_branch_thumb_only) \
245   DEF_STUB(long_branch_v4t_thumb_thumb) \
246   DEF_STUB(long_branch_v4t_thumb_arm) \
247   DEF_STUB(short_branch_v4t_thumb_arm) \
248   DEF_STUB(long_branch_any_arm_pic) \
249   DEF_STUB(long_branch_any_thumb_pic) \
250   DEF_STUB(long_branch_v4t_thumb_thumb_pic) \
251   DEF_STUB(long_branch_v4t_arm_thumb_pic) \
252   DEF_STUB(long_branch_v4t_thumb_arm_pic) \
253   DEF_STUB(long_branch_thumb_only_pic) \
254   DEF_STUB(a8_veneer_b_cond) \
255   DEF_STUB(a8_veneer_b) \
256   DEF_STUB(a8_veneer_bl) \
257   DEF_STUB(a8_veneer_blx) \
258   DEF_STUB(v4_veneer_bx)
259
260 // Stub types.
261
262 #define DEF_STUB(x) arm_stub_##x,
263 typedef enum
264   {
265     arm_stub_none,
266     DEF_STUBS
267
268     // First reloc stub type.
269     arm_stub_reloc_first = arm_stub_long_branch_any_any,
270     // Last  reloc stub type.
271     arm_stub_reloc_last = arm_stub_long_branch_thumb_only_pic,
272
273     // First Cortex-A8 stub type.
274     arm_stub_cortex_a8_first = arm_stub_a8_veneer_b_cond,
275     // Last Cortex-A8 stub type.
276     arm_stub_cortex_a8_last = arm_stub_a8_veneer_blx,
277
278     // Last stub type.
279     arm_stub_type_last = arm_stub_v4_veneer_bx
280   } Stub_type;
281 #undef DEF_STUB
282
283 // Stub template class.  Templates are meant to be read-only objects.
284 // A stub template for a stub type contains all read-only attributes
285 // common to all stubs of the same type.
286
287 class Stub_template
288 {
289  public:
290   Stub_template(Stub_type, const Insn_template*, size_t);
291
292   ~Stub_template()
293   { }
294
295   // Return stub type.
296   Stub_type
297   type() const
298   { return this->type_; }
299
300   // Return an array of instruction templates.
301   const Insn_template*
302   insns() const
303   { return this->insns_; }
304
305   // Return size of template in number of instructions.
306   size_t
307   insn_count() const
308   { return this->insn_count_; }
309
310   // Return size of template in bytes.
311   size_t
312   size() const
313   { return this->size_; }
314
315   // Return alignment of the stub template.
316   unsigned
317   alignment() const
318   { return this->alignment_; }
319
320   // Return whether entry point is in thumb mode.
321   bool
322   entry_in_thumb_mode() const
323   { return this->entry_in_thumb_mode_; }
324
325   // Return number of relocations in this template.
326   size_t
327   reloc_count() const
328   { return this->relocs_.size(); }
329
330   // Return index of the I-th instruction with relocation.
331   size_t
332   reloc_insn_index(size_t i) const
333   {
334     gold_assert(i < this->relocs_.size());
335     return this->relocs_[i].first;
336   }
337
338   // Return the offset of the I-th instruction with relocation from the
339   // beginning of the stub.
340   section_size_type
341   reloc_offset(size_t i) const
342   {
343     gold_assert(i < this->relocs_.size());
344     return this->relocs_[i].second;
345   }
346
347  private:
348   // This contains information about an instruction template with a relocation
349   // and its offset from start of stub.
350   typedef std::pair<size_t, section_size_type> Reloc;
351
352   // A Stub_template may not be copied.  We want to share templates as much
353   // as possible.
354   Stub_template(const Stub_template&);
355   Stub_template& operator=(const Stub_template&);
356
357   // Stub type.
358   Stub_type type_;
359   // Points to an array of Insn_templates.
360   const Insn_template* insns_;
361   // Number of Insn_templates in insns_[].
362   size_t insn_count_;
363   // Size of templated instructions in bytes.
364   size_t size_;
365   // Alignment of templated instructions.
366   unsigned alignment_;
367   // Flag to indicate if entry is in thumb mode.
368   bool entry_in_thumb_mode_;
369   // A table of reloc instruction indices and offsets.  We can find these by
370   // looking at the instruction templates but we pre-compute and then stash
371   // them here for speed.
372   std::vector<Reloc> relocs_;
373 };
374
375 //
376 // A class for code stubs.  This is a base class for different type of
377 // stubs used in the ARM target.
378 //
379
380 class Stub
381 {
382  private:
383   static const section_offset_type invalid_offset =
384     static_cast<section_offset_type>(-1);
385
386  public:
387   Stub(const Stub_template* stub_template)
388     : stub_template_(stub_template), offset_(invalid_offset)
389   { }
390
391   virtual
392    ~Stub()
393   { }
394
395   // Return the stub template.
396   const Stub_template*
397   stub_template() const
398   { return this->stub_template_; }
399
400   // Return offset of code stub from beginning of its containing stub table.
401   section_offset_type
402   offset() const
403   {
404     gold_assert(this->offset_ != invalid_offset);
405     return this->offset_;
406   }
407
408   // Set offset of code stub from beginning of its containing stub table.
409   void
410   set_offset(section_offset_type offset)
411   { this->offset_ = offset; }
412
413   // Return the relocation target address of the i-th relocation in the
414   // stub.  This must be defined in a child class.
415   Arm_address
416   reloc_target(size_t i)
417   { return this->do_reloc_target(i); }
418
419   // Write a stub at output VIEW.  BIG_ENDIAN select how a stub is written.
420   void
421   write(unsigned char* view, section_size_type view_size, bool big_endian)
422   { this->do_write(view, view_size, big_endian); }
423
424   // Return the instruction for THUMB16_SPECIAL_TYPE instruction template
425   // for the i-th instruction.
426   uint16_t
427   thumb16_special(size_t i)
428   { return this->do_thumb16_special(i); }
429
430  protected:
431   // This must be defined in the child class.
432   virtual Arm_address
433   do_reloc_target(size_t) = 0;
434
435   // This may be overridden in the child class.
436   virtual void
437   do_write(unsigned char* view, section_size_type view_size, bool big_endian)
438   {
439     if (big_endian)
440       this->do_fixed_endian_write<true>(view, view_size);
441     else
442       this->do_fixed_endian_write<false>(view, view_size);
443   }
444
445   // This must be overridden if a child class uses the THUMB16_SPECIAL_TYPE
446   // instruction template.
447   virtual uint16_t
448   do_thumb16_special(size_t)
449   { gold_unreachable(); }
450
451  private:
452   // A template to implement do_write.
453   template<bool big_endian>
454   void inline
455   do_fixed_endian_write(unsigned char*, section_size_type);
456
457   // Its template.
458   const Stub_template* stub_template_;
459   // Offset within the section of containing this stub.
460   section_offset_type offset_;
461 };
462
463 // Reloc stub class.  These are stubs we use to fix up relocation because
464 // of limited branch ranges.
465
466 class Reloc_stub : public Stub
467 {
468  public:
469   static const unsigned int invalid_index = static_cast<unsigned int>(-1);
470   // We assume we never jump to this address.
471   static const Arm_address invalid_address = static_cast<Arm_address>(-1);
472
473   // Return destination address.
474   Arm_address
475   destination_address() const
476   {
477     gold_assert(this->destination_address_ != this->invalid_address);
478     return this->destination_address_;
479   }
480
481   // Set destination address.
482   void
483   set_destination_address(Arm_address address)
484   {
485     gold_assert(address != this->invalid_address);
486     this->destination_address_ = address;
487   }
488
489   // Reset destination address.
490   void
491   reset_destination_address()
492   { this->destination_address_ = this->invalid_address; }
493
494   // Determine stub type for a branch of a relocation of R_TYPE going
495   // from BRANCH_ADDRESS to BRANCH_TARGET.  If TARGET_IS_THUMB is set,
496   // the branch target is a thumb instruction.  TARGET is used for look
497   // up ARM-specific linker settings.
498   static Stub_type
499   stub_type_for_reloc(unsigned int r_type, Arm_address branch_address,
500                       Arm_address branch_target, bool target_is_thumb);
501
502   // Reloc_stub key.  A key is logically a triplet of a stub type, a symbol
503   // and an addend.  Since we treat global and local symbol differently, we
504   // use a Symbol object for a global symbol and a object-index pair for
505   // a local symbol.
506   class Key
507   {
508    public:
509     // If SYMBOL is not null, this is a global symbol, we ignore RELOBJ and
510     // R_SYM.  Otherwise, this is a local symbol and RELOBJ must non-NULL
511     // and R_SYM must not be invalid_index.
512     Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj,
513         unsigned int r_sym, int32_t addend)
514       : stub_type_(stub_type), addend_(addend)
515     {
516       if (symbol != NULL)
517         {
518           this->r_sym_ = Reloc_stub::invalid_index;
519           this->u_.symbol = symbol;
520         }
521       else
522         {
523           gold_assert(relobj != NULL && r_sym != invalid_index);
524           this->r_sym_ = r_sym;
525           this->u_.relobj = relobj;
526         }
527     }
528
529     ~Key()
530     { }
531
532     // Accessors: Keys are meant to be read-only object so no modifiers are
533     // provided.
534
535     // Return stub type.
536     Stub_type
537     stub_type() const
538     { return this->stub_type_; }
539
540     // Return the local symbol index or invalid_index.
541     unsigned int
542     r_sym() const
543     { return this->r_sym_; }
544
545     // Return the symbol if there is one.
546     const Symbol*
547     symbol() const
548     { return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; }
549
550     // Return the relobj if there is one.
551     const Relobj*
552     relobj() const
553     { return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; }
554
555     // Whether this equals to another key k.
556     bool
557     eq(const Key& k) const
558     {
559       return ((this->stub_type_ == k.stub_type_)
560               && (this->r_sym_ == k.r_sym_)
561               && ((this->r_sym_ != Reloc_stub::invalid_index)
562                   ? (this->u_.relobj == k.u_.relobj)
563                   : (this->u_.symbol == k.u_.symbol))
564               && (this->addend_ == k.addend_));
565     }
566
567     // Return a hash value.
568     size_t
569     hash_value() const
570     {
571       return (this->stub_type_
572               ^ this->r_sym_
573               ^ gold::string_hash<char>(
574                     (this->r_sym_ != Reloc_stub::invalid_index)
575                     ? this->u_.relobj->name().c_str()
576                     : this->u_.symbol->name())
577               ^ this->addend_);
578     }
579
580     // Functors for STL associative containers.
581     struct hash
582     {
583       size_t
584       operator()(const Key& k) const
585       { return k.hash_value(); }
586     };
587
588     struct equal_to
589     {
590       bool
591       operator()(const Key& k1, const Key& k2) const
592       { return k1.eq(k2); }
593     };
594
595     // Name of key.  This is mainly for debugging.
596     std::string
597     name() const;
598
599    private:
600     // Stub type.
601     Stub_type stub_type_;
602     // If this is a local symbol, this is the index in the defining object.
603     // Otherwise, it is invalid_index for a global symbol.
604     unsigned int r_sym_;
605     // If r_sym_ is an invalid index, this points to a global symbol.
606     // Otherwise, it points to a relobj.  We used the unsized and target
607     // independent Symbol and Relobj classes instead of Sized_symbol<32> and
608     // Arm_relobj, in order to avoid making the stub class a template
609     // as most of the stub machinery is endianness-neutral.  However, it
610     // may require a bit of casting done by users of this class.
611     union
612     {
613       const Symbol* symbol;
614       const Relobj* relobj;
615     } u_;
616     // Addend associated with a reloc.
617     int32_t addend_;
618   };
619
620  protected:
621   // Reloc_stubs are created via a stub factory.  So these are protected.
622   Reloc_stub(const Stub_template* stub_template)
623     : Stub(stub_template), destination_address_(invalid_address)
624   { }
625
626   ~Reloc_stub()
627   { }
628
629   friend class Stub_factory;
630
631   // Return the relocation target address of the i-th relocation in the
632   // stub.
633   Arm_address
634   do_reloc_target(size_t i)
635   {
636     // All reloc stub have only one relocation.
637     gold_assert(i == 0);
638     return this->destination_address_;
639   }
640
641  private:
642   // Address of destination.
643   Arm_address destination_address_;
644 };
645
646 // Cortex-A8 stub class.  We need a Cortex-A8 stub to redirect any 32-bit
647 // THUMB branch that meets the following conditions:
648 //
649 // 1. The branch straddles across a page boundary. i.e. lower 12-bit of
650 //    branch address is 0xffe.
651 // 2. The branch target address is in the same page as the first word of the
652 //    branch.
653 // 3. The branch follows a 32-bit instruction which is not a branch.
654 //
655 // To do the fix up, we need to store the address of the branch instruction
656 // and its target at least.  We also need to store the original branch
657 // instruction bits for the condition code in a conditional branch.  The
658 // condition code is used in a special instruction template.  We also want
659 // to identify input sections needing Cortex-A8 workaround quickly.  We store
660 // extra information about object and section index of the code section
661 // containing a branch being fixed up.  The information is used to mark
662 // the code section when we finalize the Cortex-A8 stubs.
663 //
664
665 class Cortex_a8_stub : public Stub
666 {
667  public:
668   ~Cortex_a8_stub()
669   { }
670
671   // Return the object of the code section containing the branch being fixed
672   // up.
673   Relobj*
674   relobj() const
675   { return this->relobj_; }
676
677   // Return the section index of the code section containing the branch being
678   // fixed up.
679   unsigned int
680   shndx() const
681   { return this->shndx_; }
682
683   // Return the source address of stub.  This is the address of the original
684   // branch instruction.  LSB is 1 always set to indicate that it is a THUMB
685   // instruction.
686   Arm_address
687   source_address() const
688   { return this->source_address_; }
689
690   // Return the destination address of the stub.  This is the branch taken
691   // address of the original branch instruction.  LSB is 1 if it is a THUMB
692   // instruction address.
693   Arm_address
694   destination_address() const
695   { return this->destination_address_; }
696
697   // Return the instruction being fixed up.
698   uint32_t
699   original_insn() const
700   { return this->original_insn_; }
701
702  protected:
703   // Cortex_a8_stubs are created via a stub factory.  So these are protected.
704   Cortex_a8_stub(const Stub_template* stub_template, Relobj* relobj,
705                  unsigned int shndx, Arm_address source_address,
706                  Arm_address destination_address, uint32_t original_insn)
707     : Stub(stub_template), relobj_(relobj), shndx_(shndx),
708       source_address_(source_address | 1U),
709       destination_address_(destination_address),
710       original_insn_(original_insn)
711   { }
712
713   friend class Stub_factory;
714
715   // Return the relocation target address of the i-th relocation in the
716   // stub.
717   Arm_address
718   do_reloc_target(size_t i)
719   {
720     if (this->stub_template()->type() == arm_stub_a8_veneer_b_cond)
721       {
722         // The conditional branch veneer has two relocations.
723         gold_assert(i < 2);
724         return i == 0 ? this->source_address_ + 4 : this->destination_address_;
725       }
726     else
727       {
728         // All other Cortex-A8 stubs have only one relocation.
729         gold_assert(i == 0);
730         return this->destination_address_;
731       }
732   }
733
734   // Return an instruction for the THUMB16_SPECIAL_TYPE instruction template.
735   uint16_t
736   do_thumb16_special(size_t);
737
738  private:
739   // Object of the code section containing the branch being fixed up.
740   Relobj* relobj_;
741   // Section index of the code section containing the branch begin fixed up.
742   unsigned int shndx_;
743   // Source address of original branch.
744   Arm_address source_address_;
745   // Destination address of the original branch.
746   Arm_address destination_address_;
747   // Original branch instruction.  This is needed for copying the condition
748   // code from a condition branch to its stub.
749   uint32_t original_insn_;
750 };
751
752 // ARMv4 BX Rx branch relocation stub class.
753 class Arm_v4bx_stub : public Stub
754 {
755  public:
756   ~Arm_v4bx_stub()
757   { }
758
759   // Return the associated register.
760   uint32_t
761   reg() const
762   { return this->reg_; }
763
764  protected:
765   // Arm V4BX stubs are created via a stub factory.  So these are protected.
766   Arm_v4bx_stub(const Stub_template* stub_template, const uint32_t reg)
767     : Stub(stub_template), reg_(reg)
768   { }
769
770   friend class Stub_factory;
771
772   // Return the relocation target address of the i-th relocation in the
773   // stub.
774   Arm_address
775   do_reloc_target(size_t)
776   { gold_unreachable(); }
777
778   // This may be overridden in the child class.
779   virtual void
780   do_write(unsigned char* view, section_size_type view_size, bool big_endian)
781   {
782     if (big_endian)
783       this->do_fixed_endian_v4bx_write<true>(view, view_size);
784     else
785       this->do_fixed_endian_v4bx_write<false>(view, view_size);
786   }
787
788  private:
789   // A template to implement do_write.
790   template<bool big_endian>
791   void inline
792   do_fixed_endian_v4bx_write(unsigned char* view, section_size_type)
793   {
794     const Insn_template* insns = this->stub_template()->insns();
795     elfcpp::Swap<32, big_endian>::writeval(view,
796                                            (insns[0].data()
797                                            + (this->reg_ << 16)));
798     view += insns[0].size();
799     elfcpp::Swap<32, big_endian>::writeval(view,
800                                            (insns[1].data() + this->reg_));
801     view += insns[1].size();
802     elfcpp::Swap<32, big_endian>::writeval(view,
803                                            (insns[2].data() + this->reg_));
804   }
805
806   // A register index (r0-r14), which is associated with the stub.
807   uint32_t reg_;
808 };
809
810 // Stub factory class.
811
812 class Stub_factory
813 {
814  public:
815   // Return the unique instance of this class.
816   static const Stub_factory&
817   get_instance()
818   {
819     static Stub_factory singleton;
820     return singleton;
821   }
822
823   // Make a relocation stub.
824   Reloc_stub*
825   make_reloc_stub(Stub_type stub_type) const
826   {
827     gold_assert(stub_type >= arm_stub_reloc_first
828                 && stub_type <= arm_stub_reloc_last);
829     return new Reloc_stub(this->stub_templates_[stub_type]);
830   }
831
832   // Make a Cortex-A8 stub.
833   Cortex_a8_stub*
834   make_cortex_a8_stub(Stub_type stub_type, Relobj* relobj, unsigned int shndx,
835                       Arm_address source, Arm_address destination,
836                       uint32_t original_insn) const
837   {
838     gold_assert(stub_type >= arm_stub_cortex_a8_first
839                 && stub_type <= arm_stub_cortex_a8_last);
840     return new Cortex_a8_stub(this->stub_templates_[stub_type], relobj, shndx,
841                               source, destination, original_insn);
842   }
843
844   // Make an ARM V4BX relocation stub.
845   // This method creates a stub from the arm_stub_v4_veneer_bx template only.
846   Arm_v4bx_stub*
847   make_arm_v4bx_stub(uint32_t reg) const
848   {
849     gold_assert(reg < 0xf);
850     return new Arm_v4bx_stub(this->stub_templates_[arm_stub_v4_veneer_bx],
851                              reg);
852   }
853
854  private:
855   // Constructor and destructor are protected since we only return a single
856   // instance created in Stub_factory::get_instance().
857
858   Stub_factory();
859
860   // A Stub_factory may not be copied since it is a singleton.
861   Stub_factory(const Stub_factory&);
862   Stub_factory& operator=(Stub_factory&);
863
864   // Stub templates.  These are initialized in the constructor.
865   const Stub_template* stub_templates_[arm_stub_type_last+1];
866 };
867
868 // A class to hold stubs for the ARM target.
869
870 template<bool big_endian>
871 class Stub_table : public Output_data
872 {
873  public:
874   Stub_table(Arm_input_section<big_endian>* owner)
875     : Output_data(), owner_(owner), reloc_stubs_(), reloc_stubs_size_(0),
876       reloc_stubs_addralign_(1), cortex_a8_stubs_(), arm_v4bx_stubs_(0xf),
877       prev_data_size_(0), prev_addralign_(1)
878   { }
879
880   ~Stub_table()
881   { }
882
883   // Owner of this stub table.
884   Arm_input_section<big_endian>*
885   owner() const
886   { return this->owner_; }
887
888   // Whether this stub table is empty.
889   bool
890   empty() const
891   {
892     return (this->reloc_stubs_.empty()
893             && this->cortex_a8_stubs_.empty()
894             && this->arm_v4bx_stubs_.empty());
895   }
896
897   // Return the current data size.
898   off_t
899   current_data_size() const
900   { return this->current_data_size_for_child(); }
901
902   // Add a STUB using KEY.  The caller is responsible for avoiding addition
903   // if a STUB with the same key has already been added.
904   void
905   add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key)
906   {
907     const Stub_template* stub_template = stub->stub_template();
908     gold_assert(stub_template->type() == key.stub_type());
909     this->reloc_stubs_[key] = stub;
910
911     // Assign stub offset early.  We can do this because we never remove
912     // reloc stubs and they are in the beginning of the stub table.
913     uint64_t align = stub_template->alignment();
914     this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_, align);
915     stub->set_offset(this->reloc_stubs_size_);
916     this->reloc_stubs_size_ += stub_template->size();
917     this->reloc_stubs_addralign_ =
918       std::max(this->reloc_stubs_addralign_, align);
919   }
920
921   // Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS.
922   // The caller is responsible for avoiding addition if a STUB with the same
923   // address has already been added.
924   void
925   add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub)
926   {
927     std::pair<Arm_address, Cortex_a8_stub*> value(address, stub);
928     this->cortex_a8_stubs_.insert(value);
929   }
930
931   // Add an ARM V4BX relocation stub. A register index will be retrieved
932   // from the stub.
933   void
934   add_arm_v4bx_stub(Arm_v4bx_stub* stub)
935   {
936     gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL);
937     this->arm_v4bx_stubs_[stub->reg()] = stub;
938   }
939
940   // Remove all Cortex-A8 stubs.
941   void
942   remove_all_cortex_a8_stubs();
943
944   // Look up a relocation stub using KEY.  Return NULL if there is none.
945   Reloc_stub*
946   find_reloc_stub(const Reloc_stub::Key& key) const
947   {
948     typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
949     return (p != this->reloc_stubs_.end()) ? p->second : NULL;
950   }
951
952   // Look up an arm v4bx relocation stub using the register index.
953   // Return NULL if there is none.
954   Arm_v4bx_stub*
955   find_arm_v4bx_stub(const uint32_t reg) const
956   {
957     gold_assert(reg < 0xf);
958     return this->arm_v4bx_stubs_[reg];
959   }
960
961   // Relocate stubs in this stub table.
962   void
963   relocate_stubs(const Relocate_info<32, big_endian>*,
964                  Target_arm<big_endian>*, Output_section*,
965                  unsigned char*, Arm_address, section_size_type);
966
967   // Update data size and alignment at the end of a relaxation pass.  Return
968   // true if either data size or alignment is different from that of the
969   // previous relaxation pass.
970   bool
971   update_data_size_and_addralign();
972
973   // Finalize stubs.  Set the offsets of all stubs and mark input sections
974   // needing the Cortex-A8 workaround.
975   void
976   finalize_stubs();
977
978   // Apply Cortex-A8 workaround to an address range.
979   void
980   apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*,
981                                               unsigned char*, Arm_address,
982                                               section_size_type);
983
984  protected:
985   // Write out section contents.
986   void
987   do_write(Output_file*);
988
989   // Return the required alignment.
990   uint64_t
991   do_addralign() const
992   { return this->prev_addralign_; }
993
994   // Reset address and file offset.
995   void
996   do_reset_address_and_file_offset()
997   { this->set_current_data_size_for_child(this->prev_data_size_); }
998
999   // Set final data size.
1000   void
1001   set_final_data_size()
1002   { this->set_data_size(this->current_data_size()); }
1003
1004  private:
1005   // Relocate one stub.
1006   void
1007   relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
1008                 Target_arm<big_endian>*, Output_section*,
1009                 unsigned char*, Arm_address, section_size_type);
1010
1011   // Unordered map of relocation stubs.
1012   typedef
1013     Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
1014                   Reloc_stub::Key::equal_to>
1015     Reloc_stub_map;
1016
1017   // List of Cortex-A8 stubs ordered by addresses of branches being
1018   // fixed up in output.
1019   typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list;
1020   // List of Arm V4BX relocation stubs ordered by associated registers.
1021   typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list;
1022
1023   // Owner of this stub table.
1024   Arm_input_section<big_endian>* owner_;
1025   // The relocation stubs.
1026   Reloc_stub_map reloc_stubs_;
1027   // Size of reloc stubs.
1028   off_t reloc_stubs_size_;
1029   // Maximum address alignment of reloc stubs.
1030   uint64_t reloc_stubs_addralign_;
1031   // The cortex_a8_stubs.
1032   Cortex_a8_stub_list cortex_a8_stubs_;
1033   // The Arm V4BX relocation stubs.
1034   Arm_v4bx_stub_list arm_v4bx_stubs_;
1035   // data size of this in the previous pass.
1036   off_t prev_data_size_;
1037   // address alignment of this in the previous pass.
1038   uint64_t prev_addralign_;
1039 };
1040
1041 // Arm_exidx_cantunwind class.  This represents an EXIDX_CANTUNWIND entry
1042 // we add to the end of an EXIDX input section that goes into the output.
1043
1044 class Arm_exidx_cantunwind : public Output_section_data
1045 {
1046  public:
1047   Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
1048     : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
1049   { }
1050
1051   // Return the object containing the section pointed by this.
1052   Relobj*
1053   relobj() const
1054   { return this->relobj_; }
1055
1056   // Return the section index of the section pointed by this.
1057   unsigned int
1058   shndx() const
1059   { return this->shndx_; }
1060
1061  protected:
1062   void
1063   do_write(Output_file* of)
1064   {
1065     if (parameters->target().is_big_endian())
1066       this->do_fixed_endian_write<true>(of);
1067     else
1068       this->do_fixed_endian_write<false>(of);
1069   }
1070
1071   // Write to a map file.
1072   void
1073   do_print_to_mapfile(Mapfile* mapfile) const
1074   { mapfile->print_output_data(this, _("** ARM cantunwind")); }
1075
1076  private:
1077   // Implement do_write for a given endianness.
1078   template<bool big_endian>
1079   void inline
1080   do_fixed_endian_write(Output_file*);
1081
1082   // The object containing the section pointed by this.
1083   Relobj* relobj_;
1084   // The section index of the section pointed by this.
1085   unsigned int shndx_;
1086 };
1087
1088 // During EXIDX coverage fix-up, we compact an EXIDX section.  The
1089 // Offset map is used to map input section offset within the EXIDX section
1090 // to the output offset from the start of this EXIDX section.
1091
1092 typedef std::map<section_offset_type, section_offset_type>
1093         Arm_exidx_section_offset_map;
1094
1095 // Arm_exidx_merged_section class.  This represents an EXIDX input section
1096 // with some of its entries merged.
1097
1098 class Arm_exidx_merged_section : public Output_relaxed_input_section
1099 {
1100  public:
1101   // Constructor for Arm_exidx_merged_section.
1102   // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
1103   // SECTION_OFFSET_MAP points to a section offset map describing how
1104   // parts of the input section are mapped to output.  DELETED_BYTES is
1105   // the number of bytes deleted from the EXIDX input section.
1106   Arm_exidx_merged_section(
1107       const Arm_exidx_input_section& exidx_input_section,
1108       const Arm_exidx_section_offset_map& section_offset_map,
1109       uint32_t deleted_bytes);
1110
1111   // Build output contents.
1112   void
1113   build_contents(const unsigned char*, section_size_type);
1114
1115   // Return the original EXIDX input section.
1116   const Arm_exidx_input_section&
1117   exidx_input_section() const
1118   { return this->exidx_input_section_; }
1119
1120   // Return the section offset map.
1121   const Arm_exidx_section_offset_map&
1122   section_offset_map() const
1123   { return this->section_offset_map_; }
1124
1125  protected:
1126   // Write merged section into file OF.
1127   void
1128   do_write(Output_file* of);
1129
1130   bool
1131   do_output_offset(const Relobj*, unsigned int, section_offset_type,
1132                   section_offset_type*) const;
1133
1134  private:
1135   // Original EXIDX input section.
1136   const Arm_exidx_input_section& exidx_input_section_;
1137   // Section offset map.
1138   const Arm_exidx_section_offset_map& section_offset_map_;
1139   // Merged section contents.  We need to keep build the merged section
1140   // and save it here to avoid accessing the original EXIDX section when
1141   // we cannot lock the sections' object.
1142   unsigned char* section_contents_;
1143 };
1144
1145 // A class to wrap an ordinary input section containing executable code.
1146
1147 template<bool big_endian>
1148 class Arm_input_section : public Output_relaxed_input_section
1149 {
1150  public:
1151   Arm_input_section(Relobj* relobj, unsigned int shndx)
1152     : Output_relaxed_input_section(relobj, shndx, 1),
1153       original_addralign_(1), original_size_(0), stub_table_(NULL),
1154       original_contents_(NULL)
1155   { }
1156
1157   ~Arm_input_section()
1158   { delete[] this->original_contents_; }
1159
1160   // Initialize.
1161   void
1162   init();
1163
1164   // Whether this is a stub table owner.
1165   bool
1166   is_stub_table_owner() const
1167   { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
1168
1169   // Return the stub table.
1170   Stub_table<big_endian>*
1171   stub_table() const
1172   { return this->stub_table_; }
1173
1174   // Set the stub_table.
1175   void
1176   set_stub_table(Stub_table<big_endian>* stub_table)
1177   { this->stub_table_ = stub_table; }
1178
1179   // Downcast a base pointer to an Arm_input_section pointer.  This is
1180   // not type-safe but we only use Arm_input_section not the base class.
1181   static Arm_input_section<big_endian>*
1182   as_arm_input_section(Output_relaxed_input_section* poris)
1183   { return static_cast<Arm_input_section<big_endian>*>(poris); }
1184
1185   // Return the original size of the section.
1186   uint32_t
1187   original_size() const
1188   { return this->original_size_; }
1189
1190  protected:
1191   // Write data to output file.
1192   void
1193   do_write(Output_file*);
1194
1195   // Return required alignment of this.
1196   uint64_t
1197   do_addralign() const
1198   {
1199     if (this->is_stub_table_owner())
1200       return std::max(this->stub_table_->addralign(),
1201                       static_cast<uint64_t>(this->original_addralign_));
1202     else
1203       return this->original_addralign_;
1204   }
1205
1206   // Finalize data size.
1207   void
1208   set_final_data_size();
1209
1210   // Reset address and file offset.
1211   void
1212   do_reset_address_and_file_offset();
1213
1214   // Output offset.
1215   bool
1216   do_output_offset(const Relobj* object, unsigned int shndx,
1217                    section_offset_type offset,
1218                    section_offset_type* poutput) const
1219   {
1220     if ((object == this->relobj())
1221         && (shndx == this->shndx())
1222         && (offset >= 0)
1223         && (offset <=
1224             convert_types<section_offset_type, uint32_t>(this->original_size_)))
1225       {
1226         *poutput = offset;
1227         return true;
1228       }
1229     else
1230       return false;
1231   }
1232
1233  private:
1234   // Copying is not allowed.
1235   Arm_input_section(const Arm_input_section&);
1236   Arm_input_section& operator=(const Arm_input_section&);
1237
1238   // Address alignment of the original input section.
1239   uint32_t original_addralign_;
1240   // Section size of the original input section.
1241   uint32_t original_size_;
1242   // Stub table.
1243   Stub_table<big_endian>* stub_table_;
1244   // Original section contents.  We have to make a copy here since the file
1245   // containing the original section may not be locked when we need to access
1246   // the contents.
1247   unsigned char* original_contents_;
1248 };
1249
1250 // Arm_exidx_fixup class.  This is used to define a number of methods
1251 // and keep states for fixing up EXIDX coverage.
1252
1253 class Arm_exidx_fixup
1254 {
1255  public:
1256   Arm_exidx_fixup(Output_section* exidx_output_section,
1257                   bool merge_exidx_entries = true)
1258     : exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE),
1259       last_inlined_entry_(0), last_input_section_(NULL),
1260       section_offset_map_(NULL), first_output_text_section_(NULL),
1261       merge_exidx_entries_(merge_exidx_entries)
1262   { }
1263
1264   ~Arm_exidx_fixup()
1265   { delete this->section_offset_map_; }
1266
1267   // Process an EXIDX section for entry merging.  SECTION_CONTENTS points
1268   // to the EXIDX contents and SECTION_SIZE is the size of the contents. Return
1269   // number of bytes to be deleted in output.  If parts of the input EXIDX
1270   // section are merged a heap allocated Arm_exidx_section_offset_map is store
1271   // in the located PSECTION_OFFSET_MAP.   The caller owns the map and is
1272   // responsible for releasing it.
1273   template<bool big_endian>
1274   uint32_t
1275   process_exidx_section(const Arm_exidx_input_section* exidx_input_section,
1276                         const unsigned char* section_contents,
1277                         section_size_type section_size,
1278                         Arm_exidx_section_offset_map** psection_offset_map);
1279
1280   // Append an EXIDX_CANTUNWIND entry pointing at the end of the last
1281   // input section, if there is not one already.
1282   void
1283   add_exidx_cantunwind_as_needed();
1284
1285   // Return the output section for the text section which is linked to the
1286   // first exidx input in output.
1287   Output_section*
1288   first_output_text_section() const
1289   { return this->first_output_text_section_; }
1290
1291  private:
1292   // Copying is not allowed.
1293   Arm_exidx_fixup(const Arm_exidx_fixup&);
1294   Arm_exidx_fixup& operator=(const Arm_exidx_fixup&);
1295
1296   // Type of EXIDX unwind entry.
1297   enum Unwind_type
1298   {
1299     // No type.
1300     UT_NONE,
1301     // EXIDX_CANTUNWIND.
1302     UT_EXIDX_CANTUNWIND,
1303     // Inlined entry.
1304     UT_INLINED_ENTRY,
1305     // Normal entry.
1306     UT_NORMAL_ENTRY,
1307   };
1308
1309   // Process an EXIDX entry.  We only care about the second word of the
1310   // entry.  Return true if the entry can be deleted.
1311   bool
1312   process_exidx_entry(uint32_t second_word);
1313
1314   // Update the current section offset map during EXIDX section fix-up.
1315   // If there is no map, create one.  INPUT_OFFSET is the offset of a
1316   // reference point, DELETED_BYTES is the number of deleted by in the
1317   // section so far.  If DELETE_ENTRY is true, the reference point and
1318   // all offsets after the previous reference point are discarded.
1319   void
1320   update_offset_map(section_offset_type input_offset,
1321                     section_size_type deleted_bytes, bool delete_entry);
1322
1323   // EXIDX output section.
1324   Output_section* exidx_output_section_;
1325   // Unwind type of the last EXIDX entry processed.
1326   Unwind_type last_unwind_type_;
1327   // Last seen inlined EXIDX entry.
1328   uint32_t last_inlined_entry_;
1329   // Last processed EXIDX input section.
1330   const Arm_exidx_input_section* last_input_section_;
1331   // Section offset map created in process_exidx_section.
1332   Arm_exidx_section_offset_map* section_offset_map_;
1333   // Output section for the text section which is linked to the first exidx
1334   // input in output.
1335   Output_section* first_output_text_section_;
1336
1337   bool merge_exidx_entries_;
1338 };
1339
1340 // Arm output section class.  This is defined mainly to add a number of
1341 // stub generation methods.
1342
1343 template<bool big_endian>
1344 class Arm_output_section : public Output_section
1345 {
1346  public:
1347   typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list;
1348
1349   // We need to force SHF_LINK_ORDER in a SHT_ARM_EXIDX section.
1350   Arm_output_section(const char* name, elfcpp::Elf_Word type,
1351                      elfcpp::Elf_Xword flags)
1352     : Output_section(name, type,
1353                      (type == elfcpp::SHT_ARM_EXIDX
1354                       ? flags | elfcpp::SHF_LINK_ORDER
1355                       : flags))
1356   {
1357     if (type == elfcpp::SHT_ARM_EXIDX)
1358       this->set_always_keeps_input_sections();
1359   }
1360
1361   ~Arm_output_section()
1362   { }
1363
1364   // Group input sections for stub generation.
1365   void
1366   group_sections(section_size_type, bool, Target_arm<big_endian>*, const Task*);
1367
1368   // Downcast a base pointer to an Arm_output_section pointer.  This is
1369   // not type-safe but we only use Arm_output_section not the base class.
1370   static Arm_output_section<big_endian>*
1371   as_arm_output_section(Output_section* os)
1372   { return static_cast<Arm_output_section<big_endian>*>(os); }
1373
1374   // Append all input text sections in this into LIST.
1375   void
1376   append_text_sections_to_list(Text_section_list* list);
1377
1378   // Fix EXIDX coverage of this EXIDX output section.  SORTED_TEXT_SECTION
1379   // is a list of text input sections sorted in ascending order of their
1380   // output addresses.
1381   void
1382   fix_exidx_coverage(Layout* layout,
1383                      const Text_section_list& sorted_text_section,
1384                      Symbol_table* symtab,
1385                      bool merge_exidx_entries,
1386                      const Task* task);
1387
1388   // Link an EXIDX section into its corresponding text section.
1389   void
1390   set_exidx_section_link();
1391
1392  private:
1393   // For convenience.
1394   typedef Output_section::Input_section Input_section;
1395   typedef Output_section::Input_section_list Input_section_list;
1396
1397   // Create a stub group.
1398   void create_stub_group(Input_section_list::const_iterator,
1399                          Input_section_list::const_iterator,
1400                          Input_section_list::const_iterator,
1401                          Target_arm<big_endian>*,
1402                          std::vector<Output_relaxed_input_section*>*,
1403                          const Task* task);
1404 };
1405
1406 // Arm_exidx_input_section class.  This represents an EXIDX input section.
1407
1408 class Arm_exidx_input_section
1409 {
1410  public:
1411   static const section_offset_type invalid_offset =
1412     static_cast<section_offset_type>(-1);
1413
1414   Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1415                           unsigned int link, uint32_t size,
1416                           uint32_t addralign, uint32_t text_size)
1417     : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1418       addralign_(addralign), text_size_(text_size), has_errors_(false)
1419   { }
1420
1421   ~Arm_exidx_input_section()
1422   { }
1423
1424   // Accessors:  This is a read-only class.
1425
1426   // Return the object containing this EXIDX input section.
1427   Relobj*
1428   relobj() const
1429   { return this->relobj_; }
1430
1431   // Return the section index of this EXIDX input section.
1432   unsigned int
1433   shndx() const
1434   { return this->shndx_; }
1435
1436   // Return the section index of linked text section in the same object.
1437   unsigned int
1438   link() const
1439   { return this->link_; }
1440
1441   // Return size of the EXIDX input section.
1442   uint32_t
1443   size() const
1444   { return this->size_; }
1445
1446   // Return address alignment of EXIDX input section.
1447   uint32_t
1448   addralign() const
1449   { return this->addralign_; }
1450
1451   // Return size of the associated text input section.
1452   uint32_t
1453   text_size() const
1454   { return this->text_size_; }
1455
1456   // Whether there are any errors in the EXIDX input section.
1457   bool
1458   has_errors() const
1459   { return this->has_errors_; }
1460
1461   // Set has-errors flag.
1462   void
1463   set_has_errors()
1464   { this->has_errors_ = true; }
1465
1466  private:
1467   // Object containing this.
1468   Relobj* relobj_;
1469   // Section index of this.
1470   unsigned int shndx_;
1471   // text section linked to this in the same object.
1472   unsigned int link_;
1473   // Size of this.  For ARM 32-bit is sufficient.
1474   uint32_t size_;
1475   // Address alignment of this.  For ARM 32-bit is sufficient.
1476   uint32_t addralign_;
1477   // Size of associated text section.
1478   uint32_t text_size_;
1479   // Whether this has any errors.
1480   bool has_errors_;
1481 };
1482
1483 // Arm_relobj class.
1484
1485 template<bool big_endian>
1486 class Arm_relobj : public Sized_relobj_file<32, big_endian>
1487 {
1488  public:
1489   static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1490
1491   Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1492              const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1493     : Sized_relobj_file<32, big_endian>(name, input_file, offset, ehdr),
1494       stub_tables_(), local_symbol_is_thumb_function_(),
1495       attributes_section_data_(NULL), mapping_symbols_info_(),
1496       section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1497       output_local_symbol_count_needs_update_(false),
1498       merge_flags_and_attributes_(true)
1499   { }
1500
1501   ~Arm_relobj()
1502   { delete this->attributes_section_data_; }
1503
1504   // Return the stub table of the SHNDX-th section if there is one.
1505   Stub_table<big_endian>*
1506   stub_table(unsigned int shndx) const
1507   {
1508     gold_assert(shndx < this->stub_tables_.size());
1509     return this->stub_tables_[shndx];
1510   }
1511
1512   // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1513   void
1514   set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1515   {
1516     gold_assert(shndx < this->stub_tables_.size());
1517     this->stub_tables_[shndx] = stub_table;
1518   }
1519
1520   // Whether a local symbol is a THUMB function.  R_SYM is the symbol table
1521   // index.  This is only valid after do_count_local_symbol is called.
1522   bool
1523   local_symbol_is_thumb_function(unsigned int r_sym) const
1524   {
1525     gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1526     return this->local_symbol_is_thumb_function_[r_sym];
1527   }
1528
1529   // Scan all relocation sections for stub generation.
1530   void
1531   scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1532                           const Layout*);
1533
1534   // Convert regular input section with index SHNDX to a relaxed section.
1535   void
1536   convert_input_section_to_relaxed_section(unsigned shndx)
1537   {
1538     // The stubs have relocations and we need to process them after writing
1539     // out the stubs.  So relocation now must follow section write.
1540     this->set_section_offset(shndx, -1ULL);
1541     this->set_relocs_must_follow_section_writes();
1542   }
1543
1544   // Downcast a base pointer to an Arm_relobj pointer.  This is
1545   // not type-safe but we only use Arm_relobj not the base class.
1546   static Arm_relobj<big_endian>*
1547   as_arm_relobj(Relobj* relobj)
1548   { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1549
1550   // Processor-specific flags in ELF file header.  This is valid only after
1551   // reading symbols.
1552   elfcpp::Elf_Word
1553   processor_specific_flags() const
1554   { return this->processor_specific_flags_; }
1555
1556   // Attribute section data  This is the contents of the .ARM.attribute section
1557   // if there is one.
1558   const Attributes_section_data*
1559   attributes_section_data() const
1560   { return this->attributes_section_data_; }
1561
1562   // Mapping symbol location.
1563   typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1564
1565   // Functor for STL container.
1566   struct Mapping_symbol_position_less
1567   {
1568     bool
1569     operator()(const Mapping_symbol_position& p1,
1570                const Mapping_symbol_position& p2) const
1571     {
1572       return (p1.first < p2.first
1573               || (p1.first == p2.first && p1.second < p2.second));
1574     }
1575   };
1576
1577   // We only care about the first character of a mapping symbol, so
1578   // we only store that instead of the whole symbol name.
1579   typedef std::map<Mapping_symbol_position, char,
1580                    Mapping_symbol_position_less> Mapping_symbols_info;
1581
1582   // Whether a section contains any Cortex-A8 workaround.
1583   bool
1584   section_has_cortex_a8_workaround(unsigned int shndx) const
1585   {
1586     return (this->section_has_cortex_a8_workaround_ != NULL
1587             && (*this->section_has_cortex_a8_workaround_)[shndx]);
1588   }
1589
1590   // Mark a section that has Cortex-A8 workaround.
1591   void
1592   mark_section_for_cortex_a8_workaround(unsigned int shndx)
1593   {
1594     if (this->section_has_cortex_a8_workaround_ == NULL)
1595       this->section_has_cortex_a8_workaround_ =
1596         new std::vector<bool>(this->shnum(), false);
1597     (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1598   }
1599
1600   // Return the EXIDX section of an text section with index SHNDX or NULL
1601   // if the text section has no associated EXIDX section.
1602   const Arm_exidx_input_section*
1603   exidx_input_section_by_link(unsigned int shndx) const
1604   {
1605     Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1606     return ((p != this->exidx_section_map_.end()
1607              && p->second->link() == shndx)
1608             ? p->second
1609             : NULL);
1610   }
1611
1612   // Return the EXIDX section with index SHNDX or NULL if there is none.
1613   const Arm_exidx_input_section*
1614   exidx_input_section_by_shndx(unsigned shndx) const
1615   {
1616     Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1617     return ((p != this->exidx_section_map_.end()
1618              && p->second->shndx() == shndx)
1619             ? p->second
1620             : NULL);
1621   }
1622
1623   // Whether output local symbol count needs updating.
1624   bool
1625   output_local_symbol_count_needs_update() const
1626   { return this->output_local_symbol_count_needs_update_; }
1627
1628   // Set output_local_symbol_count_needs_update flag to be true.
1629   void
1630   set_output_local_symbol_count_needs_update()
1631   { this->output_local_symbol_count_needs_update_ = true; }
1632
1633   // Update output local symbol count at the end of relaxation.
1634   void
1635   update_output_local_symbol_count();
1636
1637   // Whether we want to merge processor-specific flags and attributes.
1638   bool
1639   merge_flags_and_attributes() const
1640   { return this->merge_flags_and_attributes_; }
1641
1642   // Export list of EXIDX section indices.
1643   void
1644   get_exidx_shndx_list(std::vector<unsigned int>* list) const
1645   {
1646     list->clear();
1647     for (Exidx_section_map::const_iterator p = this->exidx_section_map_.begin();
1648          p != this->exidx_section_map_.end();
1649          ++p)
1650       {
1651         if (p->second->shndx() == p->first)
1652           list->push_back(p->first);
1653       }
1654     // Sort list to make result independent of implementation of map.
1655     std::sort(list->begin(), list->end());
1656   }
1657
1658  protected:
1659   // Post constructor setup.
1660   void
1661   do_setup()
1662   {
1663     // Call parent's setup method.
1664     Sized_relobj_file<32, big_endian>::do_setup();
1665
1666     // Initialize look-up tables.
1667     Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1668     this->stub_tables_.swap(empty_stub_table_list);
1669   }
1670
1671   // Count the local symbols.
1672   void
1673   do_count_local_symbols(Stringpool_template<char>*,
1674                          Stringpool_template<char>*);
1675
1676   void
1677   do_relocate_sections(
1678       const Symbol_table* symtab, const Layout* layout,
1679       const unsigned char* pshdrs, Output_file* of,
1680       typename Sized_relobj_file<32, big_endian>::Views* pivews);
1681
1682   // Read the symbol information.
1683   void
1684   do_read_symbols(Read_symbols_data* sd);
1685
1686   // Process relocs for garbage collection.
1687   void
1688   do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1689
1690  private:
1691
1692   // Whether a section needs to be scanned for relocation stubs.
1693   bool
1694   section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1695                                     const Relobj::Output_sections&,
1696                                     const Symbol_table*, const unsigned char*);
1697
1698   // Whether a section is a scannable text section.
1699   bool
1700   section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1701                        const Output_section*, const Symbol_table*);
1702
1703   // Whether a section needs to be scanned for the Cortex-A8 erratum.
1704   bool
1705   section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1706                                         unsigned int, Output_section*,
1707                                         const Symbol_table*);
1708
1709   // Scan a section for the Cortex-A8 erratum.
1710   void
1711   scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1712                                      unsigned int, Output_section*,
1713                                      Target_arm<big_endian>*);
1714
1715   // Find the linked text section of an EXIDX section by looking at the
1716   // first relocation of the EXIDX section.  PSHDR points to the section
1717   // headers of a relocation section and PSYMS points to the local symbols.
1718   // PSHNDX points to a location storing the text section index if found.
1719   // Return whether we can find the linked section.
1720   bool
1721   find_linked_text_section(const unsigned char* pshdr,
1722                            const unsigned char* psyms, unsigned int* pshndx);
1723
1724   //
1725   // Make a new Arm_exidx_input_section object for EXIDX section with
1726   // index SHNDX and section header SHDR.  TEXT_SHNDX is the section
1727   // index of the linked text section.
1728   void
1729   make_exidx_input_section(unsigned int shndx,
1730                            const elfcpp::Shdr<32, big_endian>& shdr,
1731                            unsigned int text_shndx,
1732                            const elfcpp::Shdr<32, big_endian>& text_shdr);
1733
1734   // Return the output address of either a plain input section or a
1735   // relaxed input section.  SHNDX is the section index.
1736   Arm_address
1737   simple_input_section_output_address(unsigned int, Output_section*);
1738
1739   typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1740   typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1741     Exidx_section_map;
1742
1743   // List of stub tables.
1744   Stub_table_list stub_tables_;
1745   // Bit vector to tell if a local symbol is a thumb function or not.
1746   // This is only valid after do_count_local_symbol is called.
1747   std::vector<bool> local_symbol_is_thumb_function_;
1748   // processor-specific flags in ELF file header.
1749   elfcpp::Elf_Word processor_specific_flags_;
1750   // Object attributes if there is an .ARM.attributes section or NULL.
1751   Attributes_section_data* attributes_section_data_;
1752   // Mapping symbols information.
1753   Mapping_symbols_info mapping_symbols_info_;
1754   // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1755   std::vector<bool>* section_has_cortex_a8_workaround_;
1756   // Map a text section to its associated .ARM.exidx section, if there is one.
1757   Exidx_section_map exidx_section_map_;
1758   // Whether output local symbol count needs updating.
1759   bool output_local_symbol_count_needs_update_;
1760   // Whether we merge processor flags and attributes of this object to
1761   // output.
1762   bool merge_flags_and_attributes_;
1763 };
1764
1765 // Arm_dynobj class.
1766
1767 template<bool big_endian>
1768 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1769 {
1770  public:
1771   Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1772              const elfcpp::Ehdr<32, big_endian>& ehdr)
1773     : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1774       processor_specific_flags_(0), attributes_section_data_(NULL)
1775   { }
1776
1777   ~Arm_dynobj()
1778   { delete this->attributes_section_data_; }
1779
1780   // Downcast a base pointer to an Arm_relobj pointer.  This is
1781   // not type-safe but we only use Arm_relobj not the base class.
1782   static Arm_dynobj<big_endian>*
1783   as_arm_dynobj(Dynobj* dynobj)
1784   { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1785
1786   // Processor-specific flags in ELF file header.  This is valid only after
1787   // reading symbols.
1788   elfcpp::Elf_Word
1789   processor_specific_flags() const
1790   { return this->processor_specific_flags_; }
1791
1792   // Attributes section data.
1793   const Attributes_section_data*
1794   attributes_section_data() const
1795   { return this->attributes_section_data_; }
1796
1797  protected:
1798   // Read the symbol information.
1799   void
1800   do_read_symbols(Read_symbols_data* sd);
1801
1802  private:
1803   // processor-specific flags in ELF file header.
1804   elfcpp::Elf_Word processor_specific_flags_;
1805   // Object attributes if there is an .ARM.attributes section or NULL.
1806   Attributes_section_data* attributes_section_data_;
1807 };
1808
1809 // Functor to read reloc addends during stub generation.
1810
1811 template<int sh_type, bool big_endian>
1812 struct Stub_addend_reader
1813 {
1814   // Return the addend for a relocation of a particular type.  Depending
1815   // on whether this is a REL or RELA relocation, read the addend from a
1816   // view or from a Reloc object.
1817   elfcpp::Elf_types<32>::Elf_Swxword
1818   operator()(
1819     unsigned int /* r_type */,
1820     const unsigned char* /* view */,
1821     const typename Reloc_types<sh_type,
1822                                32, big_endian>::Reloc& /* reloc */) const;
1823 };
1824
1825 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1826
1827 template<bool big_endian>
1828 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1829 {
1830   elfcpp::Elf_types<32>::Elf_Swxword
1831   operator()(
1832     unsigned int,
1833     const unsigned char*,
1834     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1835 };
1836
1837 // Specialized Stub_addend_reader for RELA type relocation sections.
1838 // We currently do not handle RELA type relocation sections but it is trivial
1839 // to implement the addend reader.  This is provided for completeness and to
1840 // make it easier to add support for RELA relocation sections in the future.
1841
1842 template<bool big_endian>
1843 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1844 {
1845   elfcpp::Elf_types<32>::Elf_Swxword
1846   operator()(
1847     unsigned int,
1848     const unsigned char*,
1849     const typename Reloc_types<elfcpp::SHT_RELA, 32,
1850                                big_endian>::Reloc& reloc) const
1851   { return reloc.get_r_addend(); }
1852 };
1853
1854 // Cortex_a8_reloc class.  We keep record of relocation that may need
1855 // the Cortex-A8 erratum workaround.
1856
1857 class Cortex_a8_reloc
1858 {
1859  public:
1860   Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1861                   Arm_address destination)
1862     : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1863   { }
1864
1865   ~Cortex_a8_reloc()
1866   { }
1867
1868   // Accessors:  This is a read-only class.
1869
1870   // Return the relocation stub associated with this relocation if there is
1871   // one.
1872   const Reloc_stub*
1873   reloc_stub() const
1874   { return this->reloc_stub_; }
1875
1876   // Return the relocation type.
1877   unsigned int
1878   r_type() const
1879   { return this->r_type_; }
1880
1881   // Return the destination address of the relocation.  LSB stores the THUMB
1882   // bit.
1883   Arm_address
1884   destination() const
1885   { return this->destination_; }
1886
1887  private:
1888   // Associated relocation stub if there is one, or NULL.
1889   const Reloc_stub* reloc_stub_;
1890   // Relocation type.
1891   unsigned int r_type_;
1892   // Destination address of this relocation.  LSB is used to distinguish
1893   // ARM/THUMB mode.
1894   Arm_address destination_;
1895 };
1896
1897 // Arm_output_data_got class.  We derive this from Output_data_got to add
1898 // extra methods to handle TLS relocations in a static link.
1899
1900 template<bool big_endian>
1901 class Arm_output_data_got : public Output_data_got<32, big_endian>
1902 {
1903  public:
1904   Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1905     : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1906   { }
1907
1908   // Add a static entry for the GOT entry at OFFSET.  GSYM is a global
1909   // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1910   // applied in a static link.
1911   void
1912   add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1913   { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1914
1915   // Add a static reloc for the GOT entry at OFFSET.  RELOBJ is an object
1916   // defining a local symbol with INDEX.  R_TYPE is the code of a dynamic
1917   // relocation that needs to be applied in a static link.
1918   void
1919   add_static_reloc(unsigned int got_offset, unsigned int r_type,
1920                    Sized_relobj_file<32, big_endian>* relobj,
1921                    unsigned int index)
1922   {
1923     this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1924                                                 index));
1925   }
1926
1927   // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
1928   // The first one is initialized to be 1, which is the module index for
1929   // the main executable and the second one 0.  A reloc of the type
1930   // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1931   // be applied by gold.  GSYM is a global symbol.
1932   void
1933   add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1934
1935   // Same as the above but for a local symbol in OBJECT with INDEX.
1936   void
1937   add_tls_gd32_with_static_reloc(unsigned int got_type,
1938                                  Sized_relobj_file<32, big_endian>* object,
1939                                  unsigned int index);
1940
1941  protected:
1942   // Write out the GOT table.
1943   void
1944   do_write(Output_file*);
1945
1946  private:
1947   // This class represent dynamic relocations that need to be applied by
1948   // gold because we are using TLS relocations in a static link.
1949   class Static_reloc
1950   {
1951    public:
1952     Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1953       : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1954     { this->u_.global.symbol = gsym; }
1955
1956     Static_reloc(unsigned int got_offset, unsigned int r_type,
1957           Sized_relobj_file<32, big_endian>* relobj, unsigned int index)
1958       : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1959     {
1960       this->u_.local.relobj = relobj;
1961       this->u_.local.index = index;
1962     }
1963
1964     // Return the GOT offset.
1965     unsigned int
1966     got_offset() const
1967     { return this->got_offset_; }
1968
1969     // Relocation type.
1970     unsigned int
1971     r_type() const
1972     { return this->r_type_; }
1973
1974     // Whether the symbol is global or not.
1975     bool
1976     symbol_is_global() const
1977     { return this->symbol_is_global_; }
1978
1979     // For a relocation against a global symbol, the global symbol.
1980     Symbol*
1981     symbol() const
1982     {
1983       gold_assert(this->symbol_is_global_);
1984       return this->u_.global.symbol;
1985     }
1986
1987     // For a relocation against a local symbol, the defining object.
1988     Sized_relobj_file<32, big_endian>*
1989     relobj() const
1990     {
1991       gold_assert(!this->symbol_is_global_);
1992       return this->u_.local.relobj;
1993     }
1994
1995     // For a relocation against a local symbol, the local symbol index.
1996     unsigned int
1997     index() const
1998     {
1999       gold_assert(!this->symbol_is_global_);
2000       return this->u_.local.index;
2001     }
2002
2003    private:
2004     // GOT offset of the entry to which this relocation is applied.
2005     unsigned int got_offset_;
2006     // Type of relocation.
2007     unsigned int r_type_;
2008     // Whether this relocation is against a global symbol.
2009     bool symbol_is_global_;
2010     // A global or local symbol.
2011     union
2012     {
2013       struct
2014       {
2015         // For a global symbol, the symbol itself.
2016         Symbol* symbol;
2017       } global;
2018       struct
2019       {
2020         // For a local symbol, the object defining object.
2021         Sized_relobj_file<32, big_endian>* relobj;
2022         // For a local symbol, the symbol index.
2023         unsigned int index;
2024       } local;
2025     } u_;
2026   };
2027
2028   // Symbol table of the output object.
2029   Symbol_table* symbol_table_;
2030   // Layout of the output object.
2031   Layout* layout_;
2032   // Static relocs to be applied to the GOT.
2033   std::vector<Static_reloc> static_relocs_;
2034 };
2035
2036 // The ARM target has many relocation types with odd-sizes or noncontiguous
2037 // bits.  The default handling of relocatable relocation cannot process these
2038 // relocations.  So we have to extend the default code.
2039
2040 template<bool big_endian, int sh_type, typename Classify_reloc>
2041 class Arm_scan_relocatable_relocs :
2042   public Default_scan_relocatable_relocs<sh_type, Classify_reloc>
2043 {
2044  public:
2045   // Return the strategy to use for a local symbol which is a section
2046   // symbol, given the relocation type.
2047   inline Relocatable_relocs::Reloc_strategy
2048   local_section_strategy(unsigned int r_type, Relobj*)
2049   {
2050     if (sh_type == elfcpp::SHT_RELA)
2051       return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
2052     else
2053       {
2054         if (r_type == elfcpp::R_ARM_TARGET1
2055             || r_type == elfcpp::R_ARM_TARGET2)
2056           {
2057             const Target_arm<big_endian>* arm_target =
2058               Target_arm<big_endian>::default_target();
2059             r_type = arm_target->get_real_reloc_type(r_type);
2060           }
2061
2062         switch(r_type)
2063           {
2064           // Relocations that write nothing.  These exclude R_ARM_TARGET1
2065           // and R_ARM_TARGET2.
2066           case elfcpp::R_ARM_NONE:
2067           case elfcpp::R_ARM_V4BX:
2068           case elfcpp::R_ARM_TLS_GOTDESC:
2069           case elfcpp::R_ARM_TLS_CALL:
2070           case elfcpp::R_ARM_TLS_DESCSEQ:
2071           case elfcpp::R_ARM_THM_TLS_CALL:
2072           case elfcpp::R_ARM_GOTRELAX:
2073           case elfcpp::R_ARM_GNU_VTENTRY:
2074           case elfcpp::R_ARM_GNU_VTINHERIT:
2075           case elfcpp::R_ARM_THM_TLS_DESCSEQ16:
2076           case elfcpp::R_ARM_THM_TLS_DESCSEQ32:
2077             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
2078           // These should have been converted to something else above.
2079           case elfcpp::R_ARM_TARGET1:
2080           case elfcpp::R_ARM_TARGET2:
2081             gold_unreachable();
2082           // Relocations that write full 32 bits and
2083           // have alignment of 1.
2084           case elfcpp::R_ARM_ABS32:
2085           case elfcpp::R_ARM_REL32:
2086           case elfcpp::R_ARM_SBREL32:
2087           case elfcpp::R_ARM_GOTOFF32:
2088           case elfcpp::R_ARM_BASE_PREL:
2089           case elfcpp::R_ARM_GOT_BREL:
2090           case elfcpp::R_ARM_BASE_ABS:
2091           case elfcpp::R_ARM_ABS32_NOI:
2092           case elfcpp::R_ARM_REL32_NOI:
2093           case elfcpp::R_ARM_PLT32_ABS:
2094           case elfcpp::R_ARM_GOT_ABS:
2095           case elfcpp::R_ARM_GOT_PREL:
2096           case elfcpp::R_ARM_TLS_GD32:
2097           case elfcpp::R_ARM_TLS_LDM32:
2098           case elfcpp::R_ARM_TLS_LDO32:
2099           case elfcpp::R_ARM_TLS_IE32:
2100           case elfcpp::R_ARM_TLS_LE32:
2101             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED;
2102           default:
2103             // For all other static relocations, return RELOC_SPECIAL.
2104             return Relocatable_relocs::RELOC_SPECIAL;
2105           }
2106       }
2107   }
2108 };
2109
2110 template<bool big_endian>
2111 class Target_arm : public Sized_target<32, big_endian>
2112 {
2113  public:
2114   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
2115     Reloc_section;
2116
2117   // When were are relocating a stub, we pass this as the relocation number.
2118   static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
2119
2120   Target_arm(const Target::Target_info* info = &arm_info)
2121     : Sized_target<32, big_endian>(info),
2122       got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
2123       rel_dyn_(NULL), rel_irelative_(NULL), copy_relocs_(elfcpp::R_ARM_COPY),
2124       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2125       stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2126       should_force_pic_veneer_(false),
2127       arm_input_section_map_(), attributes_section_data_(NULL),
2128       fix_cortex_a8_(false), cortex_a8_relocs_info_()
2129   { }
2130
2131   // Whether we force PCI branch veneers.
2132   bool
2133   should_force_pic_veneer() const
2134   { return this->should_force_pic_veneer_; }
2135
2136   // Set PIC veneer flag.
2137   void
2138   set_should_force_pic_veneer(bool value)
2139   { this->should_force_pic_veneer_ = value; }
2140
2141   // Whether we use THUMB-2 instructions.
2142   bool
2143   using_thumb2() const
2144   {
2145     Object_attribute* attr =
2146       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2147     int arch = attr->int_value();
2148     return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2149   }
2150
2151   // Whether we use THUMB/THUMB-2 instructions only.
2152   bool
2153   using_thumb_only() const
2154   {
2155     Object_attribute* attr =
2156       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2157
2158     if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M
2159         || attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M)
2160       return true;
2161     if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2162         && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2163       return false;
2164     attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2165     return attr->int_value() == 'M';
2166   }
2167
2168   // Whether we have an NOP instruction.  If not, use mov r0, r0 instead.
2169   bool
2170   may_use_arm_nop() const
2171   {
2172     Object_attribute* attr =
2173       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2174     int arch = attr->int_value();
2175     return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2176             || arch == elfcpp::TAG_CPU_ARCH_V6K
2177             || arch == elfcpp::TAG_CPU_ARCH_V7
2178             || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2179   }
2180
2181   // Whether we have THUMB-2 NOP.W instruction.
2182   bool
2183   may_use_thumb2_nop() const
2184   {
2185     Object_attribute* attr =
2186       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2187     int arch = attr->int_value();
2188     return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2189             || arch == elfcpp::TAG_CPU_ARCH_V7
2190             || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2191   }
2192
2193   // Whether we have v4T interworking instructions available.
2194   bool
2195   may_use_v4t_interworking() const
2196   {
2197     Object_attribute* attr =
2198       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2199     int arch = attr->int_value();
2200     return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2201             && arch != elfcpp::TAG_CPU_ARCH_V4);
2202   }
2203
2204   // Whether we have v5T interworking instructions available.
2205   bool
2206   may_use_v5t_interworking() const
2207   {
2208     Object_attribute* attr =
2209       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2210     int arch = attr->int_value();
2211     if (parameters->options().fix_arm1176())
2212       return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2213               || arch == elfcpp::TAG_CPU_ARCH_V7
2214               || arch == elfcpp::TAG_CPU_ARCH_V6_M
2215               || arch == elfcpp::TAG_CPU_ARCH_V6S_M
2216               || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2217     else
2218       return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2219               && arch != elfcpp::TAG_CPU_ARCH_V4
2220               && arch != elfcpp::TAG_CPU_ARCH_V4T);
2221   }
2222
2223   // Process the relocations to determine unreferenced sections for
2224   // garbage collection.
2225   void
2226   gc_process_relocs(Symbol_table* symtab,
2227                     Layout* layout,
2228                     Sized_relobj_file<32, big_endian>* object,
2229                     unsigned int data_shndx,
2230                     unsigned int sh_type,
2231                     const unsigned char* prelocs,
2232                     size_t reloc_count,
2233                     Output_section* output_section,
2234                     bool needs_special_offset_handling,
2235                     size_t local_symbol_count,
2236                     const unsigned char* plocal_symbols);
2237
2238   // Scan the relocations to look for symbol adjustments.
2239   void
2240   scan_relocs(Symbol_table* symtab,
2241               Layout* layout,
2242               Sized_relobj_file<32, big_endian>* object,
2243               unsigned int data_shndx,
2244               unsigned int sh_type,
2245               const unsigned char* prelocs,
2246               size_t reloc_count,
2247               Output_section* output_section,
2248               bool needs_special_offset_handling,
2249               size_t local_symbol_count,
2250               const unsigned char* plocal_symbols);
2251
2252   // Finalize the sections.
2253   void
2254   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2255
2256   // Return the value to use for a dynamic symbol which requires special
2257   // treatment.
2258   uint64_t
2259   do_dynsym_value(const Symbol*) const;
2260
2261   // Return the plt address for globals. Since we have irelative plt entries,
2262   // address calculation is not as straightforward as plt_address + plt_offset.
2263   uint64_t
2264   do_plt_address_for_global(const Symbol* gsym) const
2265   { return this->plt_section()->address_for_global(gsym); }
2266
2267   // Return the plt address for locals. 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_local(const Relobj* relobj, unsigned int symndx) const
2271   { return this->plt_section()->address_for_local(relobj, symndx); }
2272
2273   // Relocate a section.
2274   void
2275   relocate_section(const Relocate_info<32, big_endian>*,
2276                    unsigned int sh_type,
2277                    const unsigned char* prelocs,
2278                    size_t reloc_count,
2279                    Output_section* output_section,
2280                    bool needs_special_offset_handling,
2281                    unsigned char* view,
2282                    Arm_address view_address,
2283                    section_size_type view_size,
2284                    const Reloc_symbol_changes*);
2285
2286   // Scan the relocs during a relocatable link.
2287   void
2288   scan_relocatable_relocs(Symbol_table* symtab,
2289                           Layout* layout,
2290                           Sized_relobj_file<32, big_endian>* object,
2291                           unsigned int data_shndx,
2292                           unsigned int sh_type,
2293                           const unsigned char* prelocs,
2294                           size_t reloc_count,
2295                           Output_section* output_section,
2296                           bool needs_special_offset_handling,
2297                           size_t local_symbol_count,
2298                           const unsigned char* plocal_symbols,
2299                           Relocatable_relocs*);
2300
2301   // Emit relocations for a section.
2302   void
2303   relocate_relocs(const Relocate_info<32, big_endian>*,
2304                   unsigned int sh_type,
2305                   const unsigned char* prelocs,
2306                   size_t reloc_count,
2307                   Output_section* output_section,
2308                   typename elfcpp::Elf_types<32>::Elf_Off
2309                     offset_in_output_section,
2310                   const Relocatable_relocs*,
2311                   unsigned char* view,
2312                   Arm_address view_address,
2313                   section_size_type view_size,
2314                   unsigned char* reloc_view,
2315                   section_size_type reloc_view_size);
2316
2317   // Perform target-specific processing in a relocatable link.  This is
2318   // only used if we use the relocation strategy RELOC_SPECIAL.
2319   void
2320   relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2321                                unsigned int sh_type,
2322                                const unsigned char* preloc_in,
2323                                size_t relnum,
2324                                Output_section* output_section,
2325                                typename elfcpp::Elf_types<32>::Elf_Off
2326                                  offset_in_output_section,
2327                                unsigned char* view,
2328                                typename elfcpp::Elf_types<32>::Elf_Addr
2329                                  view_address,
2330                                section_size_type view_size,
2331                                unsigned char* preloc_out);
2332
2333   // Return whether SYM is defined by the ABI.
2334   bool
2335   do_is_defined_by_abi(const Symbol* sym) const
2336   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2337
2338   // Return whether there is a GOT section.
2339   bool
2340   has_got_section() const
2341   { return this->got_ != NULL; }
2342
2343   // Return the size of the GOT section.
2344   section_size_type
2345   got_size() const
2346   {
2347     gold_assert(this->got_ != NULL);
2348     return this->got_->data_size();
2349   }
2350
2351   // Return the number of entries in the GOT.
2352   unsigned int
2353   got_entry_count() const
2354   {
2355     if (!this->has_got_section())
2356       return 0;
2357     return this->got_size() / 4;
2358   }
2359
2360   // Return the number of entries in the PLT.
2361   unsigned int
2362   plt_entry_count() const;
2363
2364   // Return the offset of the first non-reserved PLT entry.
2365   unsigned int
2366   first_plt_entry_offset() const;
2367
2368   // Return the size of each PLT entry.
2369   unsigned int
2370   plt_entry_size() const;
2371
2372   // Get the section to use for IRELATIVE relocations, create it if necessary.
2373   Reloc_section*
2374   rel_irelative_section(Layout*);
2375
2376   // Map platform-specific reloc types
2377   static unsigned int
2378   get_real_reloc_type(unsigned int r_type);
2379
2380   //
2381   // Methods to support stub-generations.
2382   //
2383
2384   // Return the stub factory
2385   const Stub_factory&
2386   stub_factory() const
2387   { return this->stub_factory_; }
2388
2389   // Make a new Arm_input_section object.
2390   Arm_input_section<big_endian>*
2391   new_arm_input_section(Relobj*, unsigned int);
2392
2393   // Find the Arm_input_section object corresponding to the SHNDX-th input
2394   // section of RELOBJ.
2395   Arm_input_section<big_endian>*
2396   find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2397
2398   // Make a new Stub_table
2399   Stub_table<big_endian>*
2400   new_stub_table(Arm_input_section<big_endian>*);
2401
2402   // Scan a section for stub generation.
2403   void
2404   scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2405                          const unsigned char*, size_t, Output_section*,
2406                          bool, const unsigned char*, Arm_address,
2407                          section_size_type);
2408
2409   // Relocate a stub.
2410   void
2411   relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2412                 Output_section*, unsigned char*, Arm_address,
2413                 section_size_type);
2414
2415   // Get the default ARM target.
2416   static Target_arm<big_endian>*
2417   default_target()
2418   {
2419     gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2420                 && parameters->target().is_big_endian() == big_endian);
2421     return static_cast<Target_arm<big_endian>*>(
2422              parameters->sized_target<32, big_endian>());
2423   }
2424
2425   // Whether NAME belongs to a mapping symbol.
2426   static bool
2427   is_mapping_symbol_name(const char* name)
2428   {
2429     return (name
2430             && name[0] == '$'
2431             && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2432             && (name[2] == '\0' || name[2] == '.'));
2433   }
2434
2435   // Whether we work around the Cortex-A8 erratum.
2436   bool
2437   fix_cortex_a8() const
2438   { return this->fix_cortex_a8_; }
2439
2440   // Whether we merge exidx entries in debuginfo.
2441   bool
2442   merge_exidx_entries() const
2443   { return parameters->options().merge_exidx_entries(); }
2444
2445   // Whether we fix R_ARM_V4BX relocation.
2446   // 0 - do not fix
2447   // 1 - replace with MOV instruction (armv4 target)
2448   // 2 - make interworking veneer (>= armv4t targets only)
2449   General_options::Fix_v4bx
2450   fix_v4bx() const
2451   { return parameters->options().fix_v4bx(); }
2452
2453   // Scan a span of THUMB code section for Cortex-A8 erratum.
2454   void
2455   scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2456                                   section_size_type, section_size_type,
2457                                   const unsigned char*, Arm_address);
2458
2459   // Apply Cortex-A8 workaround to a branch.
2460   void
2461   apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2462                              unsigned char*, Arm_address);
2463
2464  protected:
2465   // Make the PLT-generator object.
2466   Output_data_plt_arm<big_endian>*
2467   make_data_plt(Layout* layout,
2468                 Arm_output_data_got<big_endian>* got,
2469                 Output_data_space* got_plt,
2470                 Output_data_space* got_irelative)
2471   { return this->do_make_data_plt(layout, got, got_plt, got_irelative); }
2472
2473   // Make an ELF object.
2474   Object*
2475   do_make_elf_object(const std::string&, Input_file*, off_t,
2476                      const elfcpp::Ehdr<32, big_endian>& ehdr);
2477
2478   Object*
2479   do_make_elf_object(const std::string&, Input_file*, off_t,
2480                      const elfcpp::Ehdr<32, !big_endian>&)
2481   { gold_unreachable(); }
2482
2483   Object*
2484   do_make_elf_object(const std::string&, Input_file*, off_t,
2485                       const elfcpp::Ehdr<64, false>&)
2486   { gold_unreachable(); }
2487
2488   Object*
2489   do_make_elf_object(const std::string&, Input_file*, off_t,
2490                      const elfcpp::Ehdr<64, true>&)
2491   { gold_unreachable(); }
2492
2493   // Make an output section.
2494   Output_section*
2495   do_make_output_section(const char* name, elfcpp::Elf_Word type,
2496                          elfcpp::Elf_Xword flags)
2497   { return new Arm_output_section<big_endian>(name, type, flags); }
2498
2499   void
2500   do_adjust_elf_header(unsigned char* view, int len);
2501
2502   // We only need to generate stubs, and hence perform relaxation if we are
2503   // not doing relocatable linking.
2504   bool
2505   do_may_relax() const
2506   { return !parameters->options().relocatable(); }
2507
2508   bool
2509   do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
2510
2511   // Determine whether an object attribute tag takes an integer, a
2512   // string or both.
2513   int
2514   do_attribute_arg_type(int tag) const;
2515
2516   // Reorder tags during output.
2517   int
2518   do_attributes_order(int num) const;
2519
2520   // This is called when the target is selected as the default.
2521   void
2522   do_select_as_default_target()
2523   {
2524     // No locking is required since there should only be one default target.
2525     // We cannot have both the big-endian and little-endian ARM targets
2526     // as the default.
2527     gold_assert(arm_reloc_property_table == NULL);
2528     arm_reloc_property_table = new Arm_reloc_property_table();
2529   }
2530
2531   // Virtual function which is set to return true by a target if
2532   // it can use relocation types to determine if a function's
2533   // pointer is taken.
2534   virtual bool
2535   do_can_check_for_function_pointers() const
2536   { return true; }
2537
2538   // Whether a section called SECTION_NAME may have function pointers to
2539   // sections not eligible for safe ICF folding.
2540   virtual bool
2541   do_section_may_have_icf_unsafe_pointers(const char* section_name) const
2542   {
2543     return (!is_prefix_of(".ARM.exidx", section_name)
2544             && !is_prefix_of(".ARM.extab", section_name)
2545             && Target::do_section_may_have_icf_unsafe_pointers(section_name));
2546   }
2547
2548   virtual void
2549   do_define_standard_symbols(Symbol_table*, Layout*);
2550
2551   virtual Output_data_plt_arm<big_endian>*
2552   do_make_data_plt(Layout* layout,
2553                    Arm_output_data_got<big_endian>* got,
2554                    Output_data_space* got_plt,
2555                    Output_data_space* got_irelative)
2556   {
2557     gold_assert(got_plt != NULL && got_irelative != NULL);
2558     return new Output_data_plt_arm_standard<big_endian>(
2559         layout, got, got_plt, got_irelative);
2560   }
2561
2562  private:
2563   // The class which scans relocations.
2564   class Scan
2565   {
2566    public:
2567     Scan()
2568       : issued_non_pic_error_(false)
2569     { }
2570
2571     static inline int
2572     get_reference_flags(unsigned int r_type);
2573
2574     inline void
2575     local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2576           Sized_relobj_file<32, big_endian>* object,
2577           unsigned int data_shndx,
2578           Output_section* output_section,
2579           const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2580           const elfcpp::Sym<32, big_endian>& lsym,
2581           bool is_discarded);
2582
2583     inline void
2584     global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2585            Sized_relobj_file<32, big_endian>* object,
2586            unsigned int data_shndx,
2587            Output_section* output_section,
2588            const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2589            Symbol* gsym);
2590
2591     inline bool
2592     local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2593                                         Sized_relobj_file<32, big_endian>* ,
2594                                         unsigned int ,
2595                                         Output_section* ,
2596                                         const elfcpp::Rel<32, big_endian>& ,
2597                                         unsigned int ,
2598                                         const elfcpp::Sym<32, big_endian>&);
2599
2600     inline bool
2601     global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2602                                          Sized_relobj_file<32, big_endian>* ,
2603                                          unsigned int ,
2604                                          Output_section* ,
2605                                          const elfcpp::Rel<32, big_endian>& ,
2606                                          unsigned int , Symbol*);
2607
2608    private:
2609     static void
2610     unsupported_reloc_local(Sized_relobj_file<32, big_endian>*,
2611                             unsigned int r_type);
2612
2613     static void
2614     unsupported_reloc_global(Sized_relobj_file<32, big_endian>*,
2615                              unsigned int r_type, Symbol*);
2616
2617     void
2618     check_non_pic(Relobj*, unsigned int r_type);
2619
2620     // Almost identical to Symbol::needs_plt_entry except that it also
2621     // handles STT_ARM_TFUNC.
2622     static bool
2623     symbol_needs_plt_entry(const Symbol* sym)
2624     {
2625       // An undefined symbol from an executable does not need a PLT entry.
2626       if (sym->is_undefined() && !parameters->options().shared())
2627         return false;
2628
2629       if (sym->type() == elfcpp::STT_GNU_IFUNC)
2630         return true;
2631
2632       return (!parameters->doing_static_link()
2633               && (sym->type() == elfcpp::STT_FUNC
2634                   || sym->type() == elfcpp::STT_ARM_TFUNC)
2635               && (sym->is_from_dynobj()
2636                   || sym->is_undefined()
2637                   || sym->is_preemptible()));
2638     }
2639
2640     inline bool
2641     possible_function_pointer_reloc(unsigned int r_type);
2642
2643     // Whether a plt entry is needed for ifunc.
2644     bool
2645     reloc_needs_plt_for_ifunc(Sized_relobj_file<32, big_endian>*,
2646                               unsigned int r_type);
2647
2648     // Whether we have issued an error about a non-PIC compilation.
2649     bool issued_non_pic_error_;
2650   };
2651
2652   // The class which implements relocation.
2653   class Relocate
2654   {
2655    public:
2656     Relocate()
2657     { }
2658
2659     ~Relocate()
2660     { }
2661
2662     // Return whether the static relocation needs to be applied.
2663     inline bool
2664     should_apply_static_reloc(const Sized_symbol<32>* gsym,
2665                               unsigned int r_type,
2666                               bool is_32bit,
2667                               Output_section* output_section);
2668
2669     // Do a relocation.  Return false if the caller should not issue
2670     // any warnings about this relocation.
2671     inline bool
2672     relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2673              Output_section*,  size_t relnum,
2674              const elfcpp::Rel<32, big_endian>&,
2675              unsigned int r_type, const Sized_symbol<32>*,
2676              const Symbol_value<32>*,
2677              unsigned char*, Arm_address,
2678              section_size_type);
2679
2680     // Return whether we want to pass flag NON_PIC_REF for this
2681     // reloc.  This means the relocation type accesses a symbol not via
2682     // GOT or PLT.
2683     static inline bool
2684     reloc_is_non_pic(unsigned int r_type)
2685     {
2686       switch (r_type)
2687         {
2688         // These relocation types reference GOT or PLT entries explicitly.
2689         case elfcpp::R_ARM_GOT_BREL:
2690         case elfcpp::R_ARM_GOT_ABS:
2691         case elfcpp::R_ARM_GOT_PREL:
2692         case elfcpp::R_ARM_GOT_BREL12:
2693         case elfcpp::R_ARM_PLT32_ABS:
2694         case elfcpp::R_ARM_TLS_GD32:
2695         case elfcpp::R_ARM_TLS_LDM32:
2696         case elfcpp::R_ARM_TLS_IE32:
2697         case elfcpp::R_ARM_TLS_IE12GP:
2698
2699         // These relocate types may use PLT entries.
2700         case elfcpp::R_ARM_CALL:
2701         case elfcpp::R_ARM_THM_CALL:
2702         case elfcpp::R_ARM_JUMP24:
2703         case elfcpp::R_ARM_THM_JUMP24:
2704         case elfcpp::R_ARM_THM_JUMP19:
2705         case elfcpp::R_ARM_PLT32:
2706         case elfcpp::R_ARM_THM_XPC22:
2707         case elfcpp::R_ARM_PREL31:
2708         case elfcpp::R_ARM_SBREL31:
2709           return false;
2710
2711         default:
2712           return true;
2713         }
2714     }
2715
2716    private:
2717     // Do a TLS relocation.
2718     inline typename Arm_relocate_functions<big_endian>::Status
2719     relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2720                  size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2721                  const Sized_symbol<32>*, const Symbol_value<32>*,
2722                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2723                  section_size_type);
2724
2725   };
2726
2727   // A class which returns the size required for a relocation type,
2728   // used while scanning relocs during a relocatable link.
2729   class Relocatable_size_for_reloc
2730   {
2731    public:
2732     unsigned int
2733     get_size_for_reloc(unsigned int, Relobj*);
2734   };
2735
2736   // Adjust TLS relocation type based on the options and whether this
2737   // is a local symbol.
2738   static tls::Tls_optimization
2739   optimize_tls_reloc(bool is_final, int r_type);
2740
2741   // Get the GOT section, creating it if necessary.
2742   Arm_output_data_got<big_endian>*
2743   got_section(Symbol_table*, Layout*);
2744
2745   // Get the GOT PLT section.
2746   Output_data_space*
2747   got_plt_section() const
2748   {
2749     gold_assert(this->got_plt_ != NULL);
2750     return this->got_plt_;
2751   }
2752
2753   // Create the PLT section.
2754   void
2755   make_plt_section(Symbol_table* symtab, Layout* layout);
2756
2757   // Create a PLT entry for a global symbol.
2758   void
2759   make_plt_entry(Symbol_table*, Layout*, Symbol*);
2760
2761   // Create a PLT entry for a local STT_GNU_IFUNC symbol.
2762   void
2763   make_local_ifunc_plt_entry(Symbol_table*, Layout*,
2764                              Sized_relobj_file<32, big_endian>* relobj,
2765                              unsigned int local_sym_index);
2766
2767   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2768   void
2769   define_tls_base_symbol(Symbol_table*, Layout*);
2770
2771   // Create a GOT entry for the TLS module index.
2772   unsigned int
2773   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2774                       Sized_relobj_file<32, big_endian>* object);
2775
2776   // Get the PLT section.
2777   const Output_data_plt_arm<big_endian>*
2778   plt_section() const
2779   {
2780     gold_assert(this->plt_ != NULL);
2781     return this->plt_;
2782   }
2783
2784   // Get the dynamic reloc section, creating it if necessary.
2785   Reloc_section*
2786   rel_dyn_section(Layout*);
2787
2788   // Get the section to use for TLS_DESC relocations.
2789   Reloc_section*
2790   rel_tls_desc_section(Layout*) const;
2791
2792   // Return true if the symbol may need a COPY relocation.
2793   // References from an executable object to non-function symbols
2794   // defined in a dynamic object may need a COPY relocation.
2795   bool
2796   may_need_copy_reloc(Symbol* gsym)
2797   {
2798     return (gsym->type() != elfcpp::STT_ARM_TFUNC
2799             && gsym->may_need_copy_reloc());
2800   }
2801
2802   // Add a potential copy relocation.
2803   void
2804   copy_reloc(Symbol_table* symtab, Layout* layout,
2805              Sized_relobj_file<32, big_endian>* object,
2806              unsigned int shndx, Output_section* output_section,
2807              Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2808   {
2809     this->copy_relocs_.copy_reloc(symtab, layout,
2810                                   symtab->get_sized_symbol<32>(sym),
2811                                   object, shndx, output_section, reloc,
2812                                   this->rel_dyn_section(layout));
2813   }
2814
2815   // Whether two EABI versions are compatible.
2816   static bool
2817   are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2818
2819   // Merge processor-specific flags from input object and those in the ELF
2820   // header of the output.
2821   void
2822   merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2823
2824   // Get the secondary compatible architecture.
2825   static int
2826   get_secondary_compatible_arch(const Attributes_section_data*);
2827
2828   // Set the secondary compatible architecture.
2829   static void
2830   set_secondary_compatible_arch(Attributes_section_data*, int);
2831
2832   static int
2833   tag_cpu_arch_combine(const char*, int, int*, int, int);
2834
2835   // Helper to print AEABI enum tag value.
2836   static std::string
2837   aeabi_enum_name(unsigned int);
2838
2839   // Return string value for TAG_CPU_name.
2840   static std::string
2841   tag_cpu_name_value(unsigned int);
2842
2843   // Query attributes object to see if integer divide instructions may be
2844   // present in an object.
2845   static bool
2846   attributes_accept_div(int arch, int profile,
2847                         const Object_attribute* div_attr);
2848
2849   // Query attributes object to see if integer divide instructions are
2850   // forbidden to be in the object.  This is not the inverse of
2851   // attributes_accept_div.
2852   static bool
2853   attributes_forbid_div(const Object_attribute* div_attr);
2854
2855   // Merge object attributes from input object and those in the output.
2856   void
2857   merge_object_attributes(const char*, const Attributes_section_data*);
2858
2859   // Helper to get an AEABI object attribute
2860   Object_attribute*
2861   get_aeabi_object_attribute(int tag) const
2862   {
2863     Attributes_section_data* pasd = this->attributes_section_data_;
2864     gold_assert(pasd != NULL);
2865     Object_attribute* attr =
2866       pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2867     gold_assert(attr != NULL);
2868     return attr;
2869   }
2870
2871   //
2872   // Methods to support stub-generations.
2873   //
2874
2875   // Group input sections for stub generation.
2876   void
2877   group_sections(Layout*, section_size_type, bool, const Task*);
2878
2879   // Scan a relocation for stub generation.
2880   void
2881   scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2882                       const Sized_symbol<32>*, unsigned int,
2883                       const Symbol_value<32>*,
2884                       elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2885
2886   // Scan a relocation section for stub.
2887   template<int sh_type>
2888   void
2889   scan_reloc_section_for_stubs(
2890       const Relocate_info<32, big_endian>* relinfo,
2891       const unsigned char* prelocs,
2892       size_t reloc_count,
2893       Output_section* output_section,
2894       bool needs_special_offset_handling,
2895       const unsigned char* view,
2896       elfcpp::Elf_types<32>::Elf_Addr view_address,
2897       section_size_type);
2898
2899   // Fix .ARM.exidx section coverage.
2900   void
2901   fix_exidx_coverage(Layout*, const Input_objects*,
2902                      Arm_output_section<big_endian>*, Symbol_table*,
2903                      const Task*);
2904
2905   // Functors for STL set.
2906   struct output_section_address_less_than
2907   {
2908     bool
2909     operator()(const Output_section* s1, const Output_section* s2) const
2910     { return s1->address() < s2->address(); }
2911   };
2912
2913   // Information about this specific target which we pass to the
2914   // general Target structure.
2915   static const Target::Target_info arm_info;
2916
2917   // The types of GOT entries needed for this platform.
2918   // These values are exposed to the ABI in an incremental link.
2919   // Do not renumber existing values without changing the version
2920   // number of the .gnu_incremental_inputs section.
2921   enum Got_type
2922   {
2923     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
2924     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
2925     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
2926     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
2927     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
2928   };
2929
2930   typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2931
2932   // Map input section to Arm_input_section.
2933   typedef Unordered_map<Section_id,
2934                         Arm_input_section<big_endian>*,
2935                         Section_id_hash>
2936           Arm_input_section_map;
2937
2938   // Map output addresses to relocs for Cortex-A8 erratum.
2939   typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2940           Cortex_a8_relocs_info;
2941
2942   // The GOT section.
2943   Arm_output_data_got<big_endian>* got_;
2944   // The PLT section.
2945   Output_data_plt_arm<big_endian>* plt_;
2946   // The GOT PLT section.
2947   Output_data_space* got_plt_;
2948   // The GOT section for IRELATIVE relocations.
2949   Output_data_space* got_irelative_;
2950   // The dynamic reloc section.
2951   Reloc_section* rel_dyn_;
2952   // The section to use for IRELATIVE relocs.
2953   Reloc_section* rel_irelative_;
2954   // Relocs saved to avoid a COPY reloc.
2955   Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2956   // Offset of the GOT entry for the TLS module index.
2957   unsigned int got_mod_index_offset_;
2958   // True if the _TLS_MODULE_BASE_ symbol has been defined.
2959   bool tls_base_symbol_defined_;
2960   // Vector of Stub_tables created.
2961   Stub_table_list stub_tables_;
2962   // Stub factory.
2963   const Stub_factory &stub_factory_;
2964   // Whether we force PIC branch veneers.
2965   bool should_force_pic_veneer_;
2966   // Map for locating Arm_input_sections.
2967   Arm_input_section_map arm_input_section_map_;
2968   // Attributes section data in output.
2969   Attributes_section_data* attributes_section_data_;
2970   // Whether we want to fix code for Cortex-A8 erratum.
2971   bool fix_cortex_a8_;
2972   // Map addresses to relocs for Cortex-A8 erratum.
2973   Cortex_a8_relocs_info cortex_a8_relocs_info_;
2974 };
2975
2976 template<bool big_endian>
2977 const Target::Target_info Target_arm<big_endian>::arm_info =
2978 {
2979   32,                   // size
2980   big_endian,           // is_big_endian
2981   elfcpp::EM_ARM,       // machine_code
2982   false,                // has_make_symbol
2983   false,                // has_resolve
2984   false,                // has_code_fill
2985   true,                 // is_default_stack_executable
2986   false,                // can_icf_inline_merge_sections
2987   '\0',                 // wrap_char
2988   "/usr/lib/libc.so.1", // dynamic_linker
2989   0x8000,               // default_text_segment_address
2990   0x1000,               // abi_pagesize (overridable by -z max-page-size)
2991   0x1000,               // common_pagesize (overridable by -z common-page-size)
2992   false,                // isolate_execinstr
2993   0,                    // rosegment_gap
2994   elfcpp::SHN_UNDEF,    // small_common_shndx
2995   elfcpp::SHN_UNDEF,    // large_common_shndx
2996   0,                    // small_common_section_flags
2997   0,                    // large_common_section_flags
2998   ".ARM.attributes",    // attributes_section
2999   "aeabi",              // attributes_vendor
3000   "_start"              // entry_symbol_name
3001 };
3002
3003 // Arm relocate functions class
3004 //
3005
3006 template<bool big_endian>
3007 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
3008 {
3009  public:
3010   typedef enum
3011   {
3012     STATUS_OKAY,        // No error during relocation.
3013     STATUS_OVERFLOW,    // Relocation overflow.
3014     STATUS_BAD_RELOC    // Relocation cannot be applied.
3015   } Status;
3016
3017  private:
3018   typedef Relocate_functions<32, big_endian> Base;
3019   typedef Arm_relocate_functions<big_endian> This;
3020
3021   // Encoding of imm16 argument for movt and movw ARM instructions
3022   // from ARM ARM:
3023   //
3024   //     imm16 := imm4 | imm12
3025   //
3026   //  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
3027   // +-------+---------------+-------+-------+-----------------------+
3028   // |       |               |imm4   |       |imm12                  |
3029   // +-------+---------------+-------+-------+-----------------------+
3030
3031   // Extract the relocation addend from VAL based on the ARM
3032   // instruction encoding described above.
3033   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3034   extract_arm_movw_movt_addend(
3035       typename elfcpp::Swap<32, big_endian>::Valtype val)
3036   {
3037     // According to the Elf ABI for ARM Architecture the immediate
3038     // field is sign-extended to form the addend.
3039     return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff));
3040   }
3041
3042   // Insert X into VAL based on the ARM instruction encoding described
3043   // above.
3044   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3045   insert_val_arm_movw_movt(
3046       typename elfcpp::Swap<32, big_endian>::Valtype val,
3047       typename elfcpp::Swap<32, big_endian>::Valtype x)
3048   {
3049     val &= 0xfff0f000;
3050     val |= x & 0x0fff;
3051     val |= (x & 0xf000) << 4;
3052     return val;
3053   }
3054
3055   // Encoding of imm16 argument for movt and movw Thumb2 instructions
3056   // from ARM ARM:
3057   //
3058   //     imm16 := imm4 | i | imm3 | imm8
3059   //
3060   //  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
3061   // +---------+-+-----------+-------++-+-----+-------+---------------+
3062   // |         |i|           |imm4   || |imm3 |       |imm8           |
3063   // +---------+-+-----------+-------++-+-----+-------+---------------+
3064
3065   // Extract the relocation addend from VAL based on the Thumb2
3066   // instruction encoding described above.
3067   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3068   extract_thumb_movw_movt_addend(
3069       typename elfcpp::Swap<32, big_endian>::Valtype val)
3070   {
3071     // According to the Elf ABI for ARM Architecture the immediate
3072     // field is sign-extended to form the addend.
3073     return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
3074                                    | ((val >> 15) & 0x0800)
3075                                    | ((val >> 4) & 0x0700)
3076                                    | (val & 0x00ff));
3077   }
3078
3079   // Insert X into VAL based on the Thumb2 instruction encoding
3080   // described above.
3081   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3082   insert_val_thumb_movw_movt(
3083       typename elfcpp::Swap<32, big_endian>::Valtype val,
3084       typename elfcpp::Swap<32, big_endian>::Valtype x)
3085   {
3086     val &= 0xfbf08f00;
3087     val |= (x & 0xf000) << 4;
3088     val |= (x & 0x0800) << 15;
3089     val |= (x & 0x0700) << 4;
3090     val |= (x & 0x00ff);
3091     return val;
3092   }
3093
3094   // Calculate the smallest constant Kn for the specified residual.
3095   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3096   static uint32_t
3097   calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3098   {
3099     int32_t msb;
3100
3101     if (residual == 0)
3102       return 0;
3103     // Determine the most significant bit in the residual and
3104     // align the resulting value to a 2-bit boundary.
3105     for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3106       ;
3107     // The desired shift is now (msb - 6), or zero, whichever
3108     // is the greater.
3109     return (((msb - 6) < 0) ? 0 : (msb - 6));
3110   }
3111
3112   // Calculate the final residual for the specified group index.
3113   // If the passed group index is less than zero, the method will return
3114   // the value of the specified residual without any change.
3115   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3116   static typename elfcpp::Swap<32, big_endian>::Valtype
3117   calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3118                     const int group)
3119   {
3120     for (int n = 0; n <= group; n++)
3121       {
3122         // Calculate which part of the value to mask.
3123         uint32_t shift = calc_grp_kn(residual);
3124         // Calculate the residual for the next time around.
3125         residual &= ~(residual & (0xff << shift));
3126       }
3127
3128     return residual;
3129   }
3130
3131   // Calculate the value of Gn for the specified group index.
3132   // We return it in the form of an encoded constant-and-rotation.
3133   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3134   static typename elfcpp::Swap<32, big_endian>::Valtype
3135   calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3136               const int group)
3137   {
3138     typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3139     uint32_t shift = 0;
3140
3141     for (int n = 0; n <= group; n++)
3142       {
3143         // Calculate which part of the value to mask.
3144         shift = calc_grp_kn(residual);
3145         // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3146         gn = residual & (0xff << shift);
3147         // Calculate the residual for the next time around.
3148         residual &= ~gn;
3149       }
3150     // Return Gn in the form of an encoded constant-and-rotation.
3151     return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3152   }
3153
3154  public:
3155   // Handle ARM long branches.
3156   static typename This::Status
3157   arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3158                     unsigned char*, const Sized_symbol<32>*,
3159                     const Arm_relobj<big_endian>*, unsigned int,
3160                     const Symbol_value<32>*, Arm_address, Arm_address, bool);
3161
3162   // Handle THUMB long branches.
3163   static typename This::Status
3164   thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3165                       unsigned char*, const Sized_symbol<32>*,
3166                       const Arm_relobj<big_endian>*, unsigned int,
3167                       const Symbol_value<32>*, Arm_address, Arm_address, bool);
3168
3169
3170   // Return the branch offset of a 32-bit THUMB branch.
3171   static inline int32_t
3172   thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3173   {
3174     // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3175     // involving the J1 and J2 bits.
3176     uint32_t s = (upper_insn & (1U << 10)) >> 10;
3177     uint32_t upper = upper_insn & 0x3ffU;
3178     uint32_t lower = lower_insn & 0x7ffU;
3179     uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3180     uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3181     uint32_t i1 = j1 ^ s ? 0 : 1;
3182     uint32_t i2 = j2 ^ s ? 0 : 1;
3183
3184     return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3185                                    | (upper << 12) | (lower << 1));
3186   }
3187
3188   // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3189   // UPPER_INSN is the original upper instruction of the branch.  Caller is
3190   // responsible for overflow checking and BLX offset adjustment.
3191   static inline uint16_t
3192   thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3193   {
3194     uint32_t s = offset < 0 ? 1 : 0;
3195     uint32_t bits = static_cast<uint32_t>(offset);
3196     return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3197   }
3198
3199   // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3200   // LOWER_INSN is the original lower instruction of the branch.  Caller is
3201   // responsible for overflow checking and BLX offset adjustment.
3202   static inline uint16_t
3203   thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3204   {
3205     uint32_t s = offset < 0 ? 1 : 0;
3206     uint32_t bits = static_cast<uint32_t>(offset);
3207     return ((lower_insn & ~0x2fffU)
3208             | ((((bits >> 23) & 1) ^ !s) << 13)
3209             | ((((bits >> 22) & 1) ^ !s) << 11)
3210             | ((bits >> 1) & 0x7ffU));
3211   }
3212
3213   // Return the branch offset of a 32-bit THUMB conditional branch.
3214   static inline int32_t
3215   thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3216   {
3217     uint32_t s = (upper_insn & 0x0400U) >> 10;
3218     uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3219     uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3220     uint32_t lower = (lower_insn & 0x07ffU);
3221     uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3222
3223     return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3224   }
3225
3226   // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3227   // instruction.  UPPER_INSN is the original upper instruction of the branch.
3228   // Caller is responsible for overflow checking.
3229   static inline uint16_t
3230   thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3231   {
3232     uint32_t s = offset < 0 ? 1 : 0;
3233     uint32_t bits = static_cast<uint32_t>(offset);
3234     return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3235   }
3236
3237   // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3238   // instruction.  LOWER_INSN is the original lower instruction of the branch.
3239   // The caller is responsible for overflow checking.
3240   static inline uint16_t
3241   thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3242   {
3243     uint32_t bits = static_cast<uint32_t>(offset);
3244     uint32_t j2 = (bits & 0x00080000U) >> 19;
3245     uint32_t j1 = (bits & 0x00040000U) >> 18;
3246     uint32_t lo = (bits & 0x00000ffeU) >> 1;
3247
3248     return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3249   }
3250
3251   // R_ARM_ABS8: S + A
3252   static inline typename This::Status
3253   abs8(unsigned char* view,
3254        const Sized_relobj_file<32, big_endian>* object,
3255        const Symbol_value<32>* psymval)
3256   {
3257     typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3258     Valtype* wv = reinterpret_cast<Valtype*>(view);
3259     Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3260     int32_t addend = Bits<8>::sign_extend32(val);
3261     Arm_address x = psymval->value(object, addend);
3262     val = Bits<32>::bit_select32(val, x, 0xffU);
3263     elfcpp::Swap<8, big_endian>::writeval(wv, val);
3264
3265     // R_ARM_ABS8 permits signed or unsigned results.
3266     return (Bits<8>::has_signed_unsigned_overflow32(x)
3267             ? This::STATUS_OVERFLOW
3268             : This::STATUS_OKAY);
3269   }
3270
3271   // R_ARM_THM_ABS5: S + A
3272   static inline typename This::Status
3273   thm_abs5(unsigned char* view,
3274        const Sized_relobj_file<32, big_endian>* object,
3275        const Symbol_value<32>* psymval)
3276   {
3277     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3278     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3279     Valtype* wv = reinterpret_cast<Valtype*>(view);
3280     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3281     Reltype addend = (val & 0x7e0U) >> 6;
3282     Reltype x = psymval->value(object, addend);
3283     val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3284     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3285     return (Bits<5>::has_overflow32(x)
3286             ? This::STATUS_OVERFLOW
3287             : This::STATUS_OKAY);
3288   }
3289
3290   // R_ARM_ABS12: S + A
3291   static inline typename This::Status
3292   abs12(unsigned char* view,
3293         const Sized_relobj_file<32, big_endian>* object,
3294         const Symbol_value<32>* psymval)
3295   {
3296     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3297     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3298     Valtype* wv = reinterpret_cast<Valtype*>(view);
3299     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3300     Reltype addend = val & 0x0fffU;
3301     Reltype x = psymval->value(object, addend);
3302     val = Bits<32>::bit_select32(val, x, 0x0fffU);
3303     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3304     return (Bits<12>::has_overflow32(x)
3305             ? This::STATUS_OVERFLOW
3306             : This::STATUS_OKAY);
3307   }
3308
3309   // R_ARM_ABS16: S + A
3310   static inline typename This::Status
3311   abs16(unsigned char* view,
3312         const Sized_relobj_file<32, big_endian>* object,
3313         const Symbol_value<32>* psymval)
3314   {
3315     typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
3316     Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view);
3317     int32_t addend = Bits<16>::sign_extend32(val);
3318     Arm_address x = psymval->value(object, addend);
3319     val = Bits<32>::bit_select32(val, x, 0xffffU);
3320     elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val);
3321
3322     // R_ARM_ABS16 permits signed or unsigned results.
3323     return (Bits<16>::has_signed_unsigned_overflow32(x)
3324             ? This::STATUS_OVERFLOW
3325             : This::STATUS_OKAY);
3326   }
3327
3328   // R_ARM_ABS32: (S + A) | T
3329   static inline typename This::Status
3330   abs32(unsigned char* view,
3331         const Sized_relobj_file<32, big_endian>* object,
3332         const Symbol_value<32>* psymval,
3333         Arm_address thumb_bit)
3334   {
3335     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3336     Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3337     Valtype x = psymval->value(object, addend) | thumb_bit;
3338     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3339     return This::STATUS_OKAY;
3340   }
3341
3342   // R_ARM_REL32: (S + A) | T - P
3343   static inline typename This::Status
3344   rel32(unsigned char* view,
3345         const Sized_relobj_file<32, big_endian>* object,
3346         const Symbol_value<32>* psymval,
3347         Arm_address address,
3348         Arm_address thumb_bit)
3349   {
3350     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3351     Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3352     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3353     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3354     return This::STATUS_OKAY;
3355   }
3356
3357   // R_ARM_THM_JUMP24: (S + A) | T - P
3358   static typename This::Status
3359   thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3360              const Symbol_value<32>* psymval, Arm_address address,
3361              Arm_address thumb_bit);
3362
3363   // R_ARM_THM_JUMP6: S + A â€“ P
3364   static inline typename This::Status
3365   thm_jump6(unsigned char* view,
3366             const Sized_relobj_file<32, big_endian>* object,
3367             const Symbol_value<32>* psymval,
3368             Arm_address address)
3369   {
3370     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3371     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3372     Valtype* wv = reinterpret_cast<Valtype*>(view);
3373     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3374     // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3375     Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3376     Reltype x = (psymval->value(object, addend) - address);
3377     val = (val & 0xfd07) | ((x  & 0x0040) << 3) | ((val & 0x003e) << 2);
3378     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3379     // CZB does only forward jumps.
3380     return ((x > 0x007e)
3381             ? This::STATUS_OVERFLOW
3382             : This::STATUS_OKAY);
3383   }
3384
3385   // R_ARM_THM_JUMP8: S + A â€“ P
3386   static inline typename This::Status
3387   thm_jump8(unsigned char* view,
3388             const Sized_relobj_file<32, big_endian>* object,
3389             const Symbol_value<32>* psymval,
3390             Arm_address address)
3391   {
3392     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3393     Valtype* wv = reinterpret_cast<Valtype*>(view);
3394     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3395     int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1);
3396     int32_t x = (psymval->value(object, addend) - address);
3397     elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00)
3398                                                 | ((x & 0x01fe) >> 1)));
3399     // We do a 9-bit overflow check because x is right-shifted by 1 bit.
3400     return (Bits<9>::has_overflow32(x)
3401             ? This::STATUS_OVERFLOW
3402             : This::STATUS_OKAY);
3403   }
3404
3405   // R_ARM_THM_JUMP11: S + A â€“ P
3406   static inline typename This::Status
3407   thm_jump11(unsigned char* view,
3408             const Sized_relobj_file<32, big_endian>* object,
3409             const Symbol_value<32>* psymval,
3410             Arm_address address)
3411   {
3412     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3413     Valtype* wv = reinterpret_cast<Valtype*>(view);
3414     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3415     int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1);
3416     int32_t x = (psymval->value(object, addend) - address);
3417     elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800)
3418                                                 | ((x & 0x0ffe) >> 1)));
3419     // We do a 12-bit overflow check because x is right-shifted by 1 bit.
3420     return (Bits<12>::has_overflow32(x)
3421             ? This::STATUS_OVERFLOW
3422             : This::STATUS_OKAY);
3423   }
3424
3425   // R_ARM_BASE_PREL: B(S) + A - P
3426   static inline typename This::Status
3427   base_prel(unsigned char* view,
3428             Arm_address origin,
3429             Arm_address address)
3430   {
3431     Base::rel32(view, origin - address);
3432     return STATUS_OKAY;
3433   }
3434
3435   // R_ARM_BASE_ABS: B(S) + A
3436   static inline typename This::Status
3437   base_abs(unsigned char* view,
3438            Arm_address origin)
3439   {
3440     Base::rel32(view, origin);
3441     return STATUS_OKAY;
3442   }
3443
3444   // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3445   static inline typename This::Status
3446   got_brel(unsigned char* view,
3447            typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3448   {
3449     Base::rel32(view, got_offset);
3450     return This::STATUS_OKAY;
3451   }
3452
3453   // R_ARM_GOT_PREL: GOT(S) + A - P
3454   static inline typename This::Status
3455   got_prel(unsigned char* view,
3456            Arm_address got_entry,
3457            Arm_address address)
3458   {
3459     Base::rel32(view, got_entry - address);
3460     return This::STATUS_OKAY;
3461   }
3462
3463   // R_ARM_PREL: (S + A) | T - P
3464   static inline typename This::Status
3465   prel31(unsigned char* view,
3466          const Sized_relobj_file<32, big_endian>* object,
3467          const Symbol_value<32>* psymval,
3468          Arm_address address,
3469          Arm_address thumb_bit)
3470   {
3471     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3472     Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3473     Valtype addend = Bits<31>::sign_extend32(val);
3474     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3475     val = Bits<32>::bit_select32(val, x, 0x7fffffffU);
3476     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val);
3477     return (Bits<31>::has_overflow32(x)
3478             ? This::STATUS_OVERFLOW
3479             : This::STATUS_OKAY);
3480   }
3481
3482   // R_ARM_MOVW_ABS_NC: (S + A) | T     (relative address base is )
3483   // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3484   // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3485   // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3486   static inline typename This::Status
3487   movw(unsigned char* view,
3488        const Sized_relobj_file<32, big_endian>* object,
3489        const Symbol_value<32>* psymval,
3490        Arm_address relative_address_base,
3491        Arm_address thumb_bit,
3492        bool check_overflow)
3493   {
3494     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3495     Valtype* wv = reinterpret_cast<Valtype*>(view);
3496     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3497     Valtype addend = This::extract_arm_movw_movt_addend(val);
3498     Valtype x = ((psymval->value(object, addend) | thumb_bit)
3499                  - relative_address_base);
3500     val = This::insert_val_arm_movw_movt(val, x);
3501     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3502     return ((check_overflow && Bits<16>::has_overflow32(x))
3503             ? This::STATUS_OVERFLOW
3504             : This::STATUS_OKAY);
3505   }
3506
3507   // R_ARM_MOVT_ABS: S + A      (relative address base is 0)
3508   // R_ARM_MOVT_PREL: S + A - P
3509   // R_ARM_MOVT_BREL: S + A - B(S)
3510   static inline typename This::Status
3511   movt(unsigned char* view,
3512        const Sized_relobj_file<32, big_endian>* object,
3513        const Symbol_value<32>* psymval,
3514        Arm_address relative_address_base)
3515   {
3516     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3517     Valtype* wv = reinterpret_cast<Valtype*>(view);
3518     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3519     Valtype addend = This::extract_arm_movw_movt_addend(val);
3520     Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3521     val = This::insert_val_arm_movw_movt(val, x);
3522     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3523     // FIXME: IHI0044D says that we should check for overflow.
3524     return This::STATUS_OKAY;
3525   }
3526
3527   // R_ARM_THM_MOVW_ABS_NC: S + A | T           (relative_address_base is 0)
3528   // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3529   // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3530   // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3531   static inline typename This::Status
3532   thm_movw(unsigned char* view,
3533            const Sized_relobj_file<32, big_endian>* object,
3534            const Symbol_value<32>* psymval,
3535            Arm_address relative_address_base,
3536            Arm_address thumb_bit,
3537            bool check_overflow)
3538   {
3539     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3540     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3541     Valtype* wv = reinterpret_cast<Valtype*>(view);
3542     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3543                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3544     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3545     Reltype x =
3546       (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3547     val = This::insert_val_thumb_movw_movt(val, x);
3548     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3549     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3550     return ((check_overflow && Bits<16>::has_overflow32(x))
3551             ? This::STATUS_OVERFLOW
3552             : This::STATUS_OKAY);
3553   }
3554
3555   // R_ARM_THM_MOVT_ABS: S + A          (relative address base is 0)
3556   // R_ARM_THM_MOVT_PREL: S + A - P
3557   // R_ARM_THM_MOVT_BREL: S + A - B(S)
3558   static inline typename This::Status
3559   thm_movt(unsigned char* view,
3560            const Sized_relobj_file<32, big_endian>* object,
3561            const Symbol_value<32>* psymval,
3562            Arm_address relative_address_base)
3563   {
3564     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3565     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3566     Valtype* wv = reinterpret_cast<Valtype*>(view);
3567     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3568                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3569     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3570     Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3571     val = This::insert_val_thumb_movw_movt(val, x);
3572     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3573     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3574     return This::STATUS_OKAY;
3575   }
3576
3577   // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3578   static inline typename This::Status
3579   thm_alu11(unsigned char* view,
3580             const Sized_relobj_file<32, big_endian>* object,
3581             const Symbol_value<32>* psymval,
3582             Arm_address address,
3583             Arm_address thumb_bit)
3584   {
3585     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3586     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3587     Valtype* wv = reinterpret_cast<Valtype*>(view);
3588     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3589                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3590
3591     //        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
3592     // -----------------------------------------------------------------------
3593     // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd     |imm8
3594     // ADDW   1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd     |imm8
3595     // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd     |imm8
3596     // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd     |imm8
3597     // SUBW   1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd     |imm8
3598     // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd     |imm8
3599
3600     // Determine a sign for the addend.
3601     const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3602                       || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3603     // Thumb2 addend encoding:
3604     // imm12 := i | imm3 | imm8
3605     int32_t addend = (insn & 0xff)
3606                      | ((insn & 0x00007000) >> 4)
3607                      | ((insn & 0x04000000) >> 15);
3608     // Apply a sign to the added.
3609     addend *= sign;
3610
3611     int32_t x = (psymval->value(object, addend) | thumb_bit)
3612                 - (address & 0xfffffffc);
3613     Reltype val = abs(x);
3614     // Mask out the value and a distinct part of the ADD/SUB opcode
3615     // (bits 7:5 of opword).
3616     insn = (insn & 0xfb0f8f00)
3617            | (val & 0xff)
3618            | ((val & 0x700) << 4)
3619            | ((val & 0x800) << 15);
3620     // Set the opcode according to whether the value to go in the
3621     // place is negative.
3622     if (x < 0)
3623       insn |= 0x00a00000;
3624
3625     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3626     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3627     return ((val > 0xfff) ?
3628             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3629   }
3630
3631   // R_ARM_THM_PC8: S + A - Pa (Thumb)
3632   static inline typename This::Status
3633   thm_pc8(unsigned char* view,
3634           const Sized_relobj_file<32, big_endian>* object,
3635           const Symbol_value<32>* psymval,
3636           Arm_address address)
3637   {
3638     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3639     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3640     Valtype* wv = reinterpret_cast<Valtype*>(view);
3641     Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3642     Reltype addend = ((insn & 0x00ff) << 2);
3643     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3644     Reltype val = abs(x);
3645     insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3646
3647     elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3648     return ((val > 0x03fc)
3649             ? This::STATUS_OVERFLOW
3650             : This::STATUS_OKAY);
3651   }
3652
3653   // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3654   static inline typename This::Status
3655   thm_pc12(unsigned char* view,
3656            const Sized_relobj_file<32, big_endian>* object,
3657            const Symbol_value<32>* psymval,
3658            Arm_address address)
3659   {
3660     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3661     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3662     Valtype* wv = reinterpret_cast<Valtype*>(view);
3663     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3664                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3665     // Determine a sign for the addend (positive if the U bit is 1).
3666     const int sign = (insn & 0x00800000) ? 1 : -1;
3667     int32_t addend = (insn & 0xfff);
3668     // Apply a sign to the added.
3669     addend *= sign;
3670
3671     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3672     Reltype val = abs(x);
3673     // Mask out and apply the value and the U bit.
3674     insn = (insn & 0xff7ff000) | (val & 0xfff);
3675     // Set the U bit according to whether the value to go in the
3676     // place is positive.
3677     if (x >= 0)
3678       insn |= 0x00800000;
3679
3680     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3681     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3682     return ((val > 0xfff) ?
3683             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3684   }
3685
3686   // R_ARM_V4BX
3687   static inline typename This::Status
3688   v4bx(const Relocate_info<32, big_endian>* relinfo,
3689        unsigned char* view,
3690        const Arm_relobj<big_endian>* object,
3691        const Arm_address address,
3692        const bool is_interworking)
3693   {
3694
3695     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3696     Valtype* wv = reinterpret_cast<Valtype*>(view);
3697     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3698
3699     // Ensure that we have a BX instruction.
3700     gold_assert((val & 0x0ffffff0) == 0x012fff10);
3701     const uint32_t reg = (val & 0xf);
3702     if (is_interworking && reg != 0xf)
3703       {
3704         Stub_table<big_endian>* stub_table =
3705             object->stub_table(relinfo->data_shndx);
3706         gold_assert(stub_table != NULL);
3707
3708         Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3709         gold_assert(stub != NULL);
3710
3711         int32_t veneer_address =
3712             stub_table->address() + stub->offset() - 8 - address;
3713         gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3714                     && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3715         // Replace with a branch to veneer (B <addr>)
3716         val = (val & 0xf0000000) | 0x0a000000
3717               | ((veneer_address >> 2) & 0x00ffffff);
3718       }
3719     else
3720       {
3721         // Preserve Rm (lowest four bits) and the condition code
3722         // (highest four bits). Other bits encode MOV PC,Rm.
3723         val = (val & 0xf000000f) | 0x01a0f000;
3724       }
3725     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3726     return This::STATUS_OKAY;
3727   }
3728
3729   // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3730   // R_ARM_ALU_PC_G0:    ((S + A) | T) - P
3731   // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3732   // R_ARM_ALU_PC_G1:    ((S + A) | T) - P
3733   // R_ARM_ALU_PC_G2:    ((S + A) | T) - P
3734   // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3735   // R_ARM_ALU_SB_G0:    ((S + A) | T) - B(S)
3736   // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3737   // R_ARM_ALU_SB_G1:    ((S + A) | T) - B(S)
3738   // R_ARM_ALU_SB_G2:    ((S + A) | T) - B(S)
3739   static inline typename This::Status
3740   arm_grp_alu(unsigned char* view,
3741         const Sized_relobj_file<32, big_endian>* object,
3742         const Symbol_value<32>* psymval,
3743         const int group,
3744         Arm_address address,
3745         Arm_address thumb_bit,
3746         bool check_overflow)
3747   {
3748     gold_assert(group >= 0 && group < 3);
3749     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3750     Valtype* wv = reinterpret_cast<Valtype*>(view);
3751     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3752
3753     // ALU group relocations are allowed only for the ADD/SUB instructions.
3754     // (0x00800000 - ADD, 0x00400000 - SUB)
3755     const Valtype opcode = insn & 0x01e00000;
3756     if (opcode != 0x00800000 && opcode != 0x00400000)
3757       return This::STATUS_BAD_RELOC;
3758
3759     // Determine a sign for the addend.
3760     const int sign = (opcode == 0x00800000) ? 1 : -1;
3761     // shifter = rotate_imm * 2
3762     const uint32_t shifter = (insn & 0xf00) >> 7;
3763     // Initial addend value.
3764     int32_t addend = insn & 0xff;
3765     // Rotate addend right by shifter.
3766     addend = (addend >> shifter) | (addend << (32 - shifter));
3767     // Apply a sign to the added.
3768     addend *= sign;
3769
3770     int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3771     Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3772     // Check for overflow if required
3773     if (check_overflow
3774         && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3775       return This::STATUS_OVERFLOW;
3776
3777     // Mask out the value and the ADD/SUB part of the opcode; take care
3778     // not to destroy the S bit.
3779     insn &= 0xff1ff000;
3780     // Set the opcode according to whether the value to go in the
3781     // place is negative.
3782     insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3783     // Encode the offset (encoded Gn).
3784     insn |= gn;
3785
3786     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3787     return This::STATUS_OKAY;
3788   }
3789
3790   // R_ARM_LDR_PC_G0: S + A - P
3791   // R_ARM_LDR_PC_G1: S + A - P
3792   // R_ARM_LDR_PC_G2: S + A - P
3793   // R_ARM_LDR_SB_G0: S + A - B(S)
3794   // R_ARM_LDR_SB_G1: S + A - B(S)
3795   // R_ARM_LDR_SB_G2: S + A - B(S)
3796   static inline typename This::Status
3797   arm_grp_ldr(unsigned char* view,
3798         const Sized_relobj_file<32, big_endian>* object,
3799         const Symbol_value<32>* psymval,
3800         const int group,
3801         Arm_address address)
3802   {
3803     gold_assert(group >= 0 && group < 3);
3804     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3805     Valtype* wv = reinterpret_cast<Valtype*>(view);
3806     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3807
3808     const int sign = (insn & 0x00800000) ? 1 : -1;
3809     int32_t addend = (insn & 0xfff) * sign;
3810     int32_t x = (psymval->value(object, addend) - address);
3811     // Calculate the relevant G(n-1) value to obtain this stage residual.
3812     Valtype residual =
3813         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3814     if (residual >= 0x1000)
3815       return This::STATUS_OVERFLOW;
3816
3817     // Mask out the value and U bit.
3818     insn &= 0xff7ff000;
3819     // Set the U bit for non-negative values.
3820     if (x >= 0)
3821       insn |= 0x00800000;
3822     insn |= residual;
3823
3824     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3825     return This::STATUS_OKAY;
3826   }
3827
3828   // R_ARM_LDRS_PC_G0: S + A - P
3829   // R_ARM_LDRS_PC_G1: S + A - P
3830   // R_ARM_LDRS_PC_G2: S + A - P
3831   // R_ARM_LDRS_SB_G0: S + A - B(S)
3832   // R_ARM_LDRS_SB_G1: S + A - B(S)
3833   // R_ARM_LDRS_SB_G2: S + A - B(S)
3834   static inline typename This::Status
3835   arm_grp_ldrs(unsigned char* view,
3836         const Sized_relobj_file<32, big_endian>* object,
3837         const Symbol_value<32>* psymval,
3838         const int group,
3839         Arm_address address)
3840   {
3841     gold_assert(group >= 0 && group < 3);
3842     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3843     Valtype* wv = reinterpret_cast<Valtype*>(view);
3844     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3845
3846     const int sign = (insn & 0x00800000) ? 1 : -1;
3847     int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3848     int32_t x = (psymval->value(object, addend) - address);
3849     // Calculate the relevant G(n-1) value to obtain this stage residual.
3850     Valtype residual =
3851         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3852    if (residual >= 0x100)
3853       return This::STATUS_OVERFLOW;
3854
3855     // Mask out the value and U bit.
3856     insn &= 0xff7ff0f0;
3857     // Set the U bit for non-negative values.
3858     if (x >= 0)
3859       insn |= 0x00800000;
3860     insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3861
3862     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3863     return This::STATUS_OKAY;
3864   }
3865
3866   // R_ARM_LDC_PC_G0: S + A - P
3867   // R_ARM_LDC_PC_G1: S + A - P
3868   // R_ARM_LDC_PC_G2: S + A - P
3869   // R_ARM_LDC_SB_G0: S + A - B(S)
3870   // R_ARM_LDC_SB_G1: S + A - B(S)
3871   // R_ARM_LDC_SB_G2: S + A - B(S)
3872   static inline typename This::Status
3873   arm_grp_ldc(unsigned char* view,
3874       const Sized_relobj_file<32, big_endian>* object,
3875       const Symbol_value<32>* psymval,
3876       const int group,
3877       Arm_address address)
3878   {
3879     gold_assert(group >= 0 && group < 3);
3880     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3881     Valtype* wv = reinterpret_cast<Valtype*>(view);
3882     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3883
3884     const int sign = (insn & 0x00800000) ? 1 : -1;
3885     int32_t addend = ((insn & 0xff) << 2) * sign;
3886     int32_t x = (psymval->value(object, addend) - address);
3887     // Calculate the relevant G(n-1) value to obtain this stage residual.
3888     Valtype residual =
3889       Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3890     if ((residual & 0x3) != 0 || residual >= 0x400)
3891       return This::STATUS_OVERFLOW;
3892
3893     // Mask out the value and U bit.
3894     insn &= 0xff7fff00;
3895     // Set the U bit for non-negative values.
3896     if (x >= 0)
3897       insn |= 0x00800000;
3898     insn |= (residual >> 2);
3899
3900     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3901     return This::STATUS_OKAY;
3902   }
3903 };
3904
3905 // Relocate ARM long branches.  This handles relocation types
3906 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3907 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3908 // undefined and we do not use PLT in this relocation.  In such a case,
3909 // the branch is converted into an NOP.
3910
3911 template<bool big_endian>
3912 typename Arm_relocate_functions<big_endian>::Status
3913 Arm_relocate_functions<big_endian>::arm_branch_common(
3914     unsigned int r_type,
3915     const Relocate_info<32, big_endian>* relinfo,
3916     unsigned char* view,
3917     const Sized_symbol<32>* gsym,
3918     const Arm_relobj<big_endian>* object,
3919     unsigned int r_sym,
3920     const Symbol_value<32>* psymval,
3921     Arm_address address,
3922     Arm_address thumb_bit,
3923     bool is_weakly_undefined_without_plt)
3924 {
3925   typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3926   Valtype* wv = reinterpret_cast<Valtype*>(view);
3927   Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3928
3929   bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3930                     && ((val & 0x0f000000UL) == 0x0a000000UL);
3931   bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3932   bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3933                           && ((val & 0x0f000000UL) == 0x0b000000UL);
3934   bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3935   bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3936
3937   // Check that the instruction is valid.
3938   if (r_type == elfcpp::R_ARM_CALL)
3939     {
3940       if (!insn_is_uncond_bl && !insn_is_blx)
3941         return This::STATUS_BAD_RELOC;
3942     }
3943   else if (r_type == elfcpp::R_ARM_JUMP24)
3944     {
3945       if (!insn_is_b && !insn_is_cond_bl)
3946         return This::STATUS_BAD_RELOC;
3947     }
3948   else if (r_type == elfcpp::R_ARM_PLT32)
3949     {
3950       if (!insn_is_any_branch)
3951         return This::STATUS_BAD_RELOC;
3952     }
3953   else if (r_type == elfcpp::R_ARM_XPC25)
3954     {
3955       // FIXME: AAELF document IH0044C does not say much about it other
3956       // than it being obsolete.
3957       if (!insn_is_any_branch)
3958         return This::STATUS_BAD_RELOC;
3959     }
3960   else
3961     gold_unreachable();
3962
3963   // A branch to an undefined weak symbol is turned into a jump to
3964   // the next instruction unless a PLT entry will be created.
3965   // Do the same for local undefined symbols.
3966   // The jump to the next instruction is optimized as a NOP depending
3967   // on the architecture.
3968   const Target_arm<big_endian>* arm_target =
3969     Target_arm<big_endian>::default_target();
3970   if (is_weakly_undefined_without_plt)
3971     {
3972       gold_assert(!parameters->options().relocatable());
3973       Valtype cond = val & 0xf0000000U;
3974       if (arm_target->may_use_arm_nop())
3975         val = cond | 0x0320f000;
3976       else
3977         val = cond | 0x01a00000;        // Using pre-UAL nop: mov r0, r0.
3978       elfcpp::Swap<32, big_endian>::writeval(wv, val);
3979       return This::STATUS_OKAY;
3980     }
3981
3982   Valtype addend = Bits<26>::sign_extend32(val << 2);
3983   Valtype branch_target = psymval->value(object, addend);
3984   int32_t branch_offset = branch_target - address;
3985
3986   // We need a stub if the branch offset is too large or if we need
3987   // to switch mode.
3988   bool may_use_blx = arm_target->may_use_v5t_interworking();
3989   Reloc_stub* stub = NULL;
3990
3991   if (!parameters->options().relocatable()
3992       && (Bits<26>::has_overflow32(branch_offset)
3993           || ((thumb_bit != 0)
3994               && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3995     {
3996       Valtype unadjusted_branch_target = psymval->value(object, 0);
3997
3998       Stub_type stub_type =
3999         Reloc_stub::stub_type_for_reloc(r_type, address,
4000                                         unadjusted_branch_target,
4001                                         (thumb_bit != 0));
4002       if (stub_type != arm_stub_none)
4003         {
4004           Stub_table<big_endian>* stub_table =
4005             object->stub_table(relinfo->data_shndx);
4006           gold_assert(stub_table != NULL);
4007
4008           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4009           stub = stub_table->find_reloc_stub(stub_key);
4010           gold_assert(stub != NULL);
4011           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4012           branch_target = stub_table->address() + stub->offset() + addend;
4013           branch_offset = branch_target - address;
4014           gold_assert(!Bits<26>::has_overflow32(branch_offset));
4015         }
4016     }
4017
4018   // At this point, if we still need to switch mode, the instruction
4019   // must either be a BLX or a BL that can be converted to a BLX.
4020   if (thumb_bit != 0)
4021     {
4022       // Turn BL to BLX.
4023       gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
4024       val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
4025     }
4026
4027   val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL);
4028   elfcpp::Swap<32, big_endian>::writeval(wv, val);
4029   return (Bits<26>::has_overflow32(branch_offset)
4030           ? This::STATUS_OVERFLOW
4031           : This::STATUS_OKAY);
4032 }
4033
4034 // Relocate THUMB long branches.  This handles relocation types
4035 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
4036 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
4037 // undefined and we do not use PLT in this relocation.  In such a case,
4038 // the branch is converted into an NOP.
4039
4040 template<bool big_endian>
4041 typename Arm_relocate_functions<big_endian>::Status
4042 Arm_relocate_functions<big_endian>::thumb_branch_common(
4043     unsigned int r_type,
4044     const Relocate_info<32, big_endian>* relinfo,
4045     unsigned char* view,
4046     const Sized_symbol<32>* gsym,
4047     const Arm_relobj<big_endian>* object,
4048     unsigned int r_sym,
4049     const Symbol_value<32>* psymval,
4050     Arm_address address,
4051     Arm_address thumb_bit,
4052     bool is_weakly_undefined_without_plt)
4053 {
4054   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4055   Valtype* wv = reinterpret_cast<Valtype*>(view);
4056   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4057   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4058
4059   // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
4060   // into account.
4061   bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
4062   bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
4063
4064   // Check that the instruction is valid.
4065   if (r_type == elfcpp::R_ARM_THM_CALL)
4066     {
4067       if (!is_bl_insn && !is_blx_insn)
4068         return This::STATUS_BAD_RELOC;
4069     }
4070   else if (r_type == elfcpp::R_ARM_THM_JUMP24)
4071     {
4072       // This cannot be a BLX.
4073       if (!is_bl_insn)
4074         return This::STATUS_BAD_RELOC;
4075     }
4076   else if (r_type == elfcpp::R_ARM_THM_XPC22)
4077     {
4078       // Check for Thumb to Thumb call.
4079       if (!is_blx_insn)
4080         return This::STATUS_BAD_RELOC;
4081       if (thumb_bit != 0)
4082         {
4083           gold_warning(_("%s: Thumb BLX instruction targets "
4084                          "thumb function '%s'."),
4085                          object->name().c_str(),
4086                          (gsym ? gsym->name() : "(local)"));
4087           // Convert BLX to BL.
4088           lower_insn |= 0x1000U;
4089         }
4090     }
4091   else
4092     gold_unreachable();
4093
4094   // A branch to an undefined weak symbol is turned into a jump to
4095   // the next instruction unless a PLT entry will be created.
4096   // The jump to the next instruction is optimized as a NOP.W for
4097   // Thumb-2 enabled architectures.
4098   const Target_arm<big_endian>* arm_target =
4099     Target_arm<big_endian>::default_target();
4100   if (is_weakly_undefined_without_plt)
4101     {
4102       gold_assert(!parameters->options().relocatable());
4103       if (arm_target->may_use_thumb2_nop())
4104         {
4105           elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4106           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4107         }
4108       else
4109         {
4110           elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4111           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4112         }
4113       return This::STATUS_OKAY;
4114     }
4115
4116   int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4117   Arm_address branch_target = psymval->value(object, addend);
4118
4119   // For BLX, bit 1 of target address comes from bit 1 of base address.
4120   bool may_use_blx = arm_target->may_use_v5t_interworking();
4121   if (thumb_bit == 0 && may_use_blx)
4122     branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4123
4124   int32_t branch_offset = branch_target - address;
4125
4126   // We need a stub if the branch offset is too large or if we need
4127   // to switch mode.
4128   bool thumb2 = arm_target->using_thumb2();
4129   if (!parameters->options().relocatable()
4130       && ((!thumb2 && Bits<23>::has_overflow32(branch_offset))
4131           || (thumb2 && Bits<25>::has_overflow32(branch_offset))
4132           || ((thumb_bit == 0)
4133               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4134                   || r_type == elfcpp::R_ARM_THM_JUMP24))))
4135     {
4136       Arm_address unadjusted_branch_target = psymval->value(object, 0);
4137
4138       Stub_type stub_type =
4139         Reloc_stub::stub_type_for_reloc(r_type, address,
4140                                         unadjusted_branch_target,
4141                                         (thumb_bit != 0));
4142
4143       if (stub_type != arm_stub_none)
4144         {
4145           Stub_table<big_endian>* stub_table =
4146             object->stub_table(relinfo->data_shndx);
4147           gold_assert(stub_table != NULL);
4148
4149           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4150           Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4151           gold_assert(stub != NULL);
4152           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4153           branch_target = stub_table->address() + stub->offset() + addend;
4154           if (thumb_bit == 0 && may_use_blx)
4155             branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4156           branch_offset = branch_target - address;
4157         }
4158     }
4159
4160   // At this point, if we still need to switch mode, the instruction
4161   // must either be a BLX or a BL that can be converted to a BLX.
4162   if (thumb_bit == 0)
4163     {
4164       gold_assert(may_use_blx
4165                   && (r_type == elfcpp::R_ARM_THM_CALL
4166                       || r_type == elfcpp::R_ARM_THM_XPC22));
4167       // Make sure this is a BLX.
4168       lower_insn &= ~0x1000U;
4169     }
4170   else
4171     {
4172       // Make sure this is a BL.
4173       lower_insn |= 0x1000U;
4174     }
4175
4176   // For a BLX instruction, make sure that the relocation is rounded up
4177   // to a word boundary.  This follows the semantics of the instruction
4178   // which specifies that bit 1 of the target address will come from bit
4179   // 1 of the base address.
4180   if ((lower_insn & 0x5000U) == 0x4000U)
4181     gold_assert((branch_offset & 3) == 0);
4182
4183   // Put BRANCH_OFFSET back into the insn.  Assumes two's complement.
4184   // We use the Thumb-2 encoding, which is safe even if dealing with
4185   // a Thumb-1 instruction by virtue of our overflow check above.  */
4186   upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4187   lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4188
4189   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4190   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4191
4192   gold_assert(!Bits<25>::has_overflow32(branch_offset));
4193
4194   return ((thumb2
4195            ? Bits<25>::has_overflow32(branch_offset)
4196            : Bits<23>::has_overflow32(branch_offset))
4197           ? This::STATUS_OVERFLOW
4198           : This::STATUS_OKAY);
4199 }
4200
4201 // Relocate THUMB-2 long conditional branches.
4202 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
4203 // undefined and we do not use PLT in this relocation.  In such a case,
4204 // the branch is converted into an NOP.
4205
4206 template<bool big_endian>
4207 typename Arm_relocate_functions<big_endian>::Status
4208 Arm_relocate_functions<big_endian>::thm_jump19(
4209     unsigned char* view,
4210     const Arm_relobj<big_endian>* object,
4211     const Symbol_value<32>* psymval,
4212     Arm_address address,
4213     Arm_address thumb_bit)
4214 {
4215   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4216   Valtype* wv = reinterpret_cast<Valtype*>(view);
4217   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4218   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4219   int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4220
4221   Arm_address branch_target = psymval->value(object, addend);
4222   int32_t branch_offset = branch_target - address;
4223
4224   // ??? Should handle interworking?  GCC might someday try to
4225   // use this for tail calls.
4226   // FIXME: We do support thumb entry to PLT yet.
4227   if (thumb_bit == 0)
4228     {
4229       gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4230       return This::STATUS_BAD_RELOC;
4231     }
4232
4233   // Put RELOCATION back into the insn.
4234   upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4235   lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4236
4237   // Put the relocated value back in the object file:
4238   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4239   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4240
4241   return (Bits<21>::has_overflow32(branch_offset)
4242           ? This::STATUS_OVERFLOW
4243           : This::STATUS_OKAY);
4244 }
4245
4246 // Get the GOT section, creating it if necessary.
4247
4248 template<bool big_endian>
4249 Arm_output_data_got<big_endian>*
4250 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4251 {
4252   if (this->got_ == NULL)
4253     {
4254       gold_assert(symtab != NULL && layout != NULL);
4255
4256       // When using -z now, we can treat .got as a relro section.
4257       // Without -z now, it is modified after program startup by lazy
4258       // PLT relocations.
4259       bool is_got_relro = parameters->options().now();
4260       Output_section_order got_order = (is_got_relro
4261                                         ? ORDER_RELRO_LAST
4262                                         : ORDER_DATA);
4263
4264       // Unlike some targets (.e.g x86), ARM does not use separate .got and
4265       // .got.plt sections in output.  The output .got section contains both
4266       // PLT and non-PLT GOT entries.
4267       this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4268
4269       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4270                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4271                                       this->got_, got_order, is_got_relro);
4272
4273       // The old GNU linker creates a .got.plt section.  We just
4274       // create another set of data in the .got section.  Note that we
4275       // always create a PLT if we create a GOT, although the PLT
4276       // might be empty.
4277       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4278       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4279                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4280                                       this->got_plt_, got_order, is_got_relro);
4281
4282       // The first three entries are reserved.
4283       this->got_plt_->set_current_data_size(3 * 4);
4284
4285       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4286       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4287                                     Symbol_table::PREDEFINED,
4288                                     this->got_plt_,
4289                                     0, 0, elfcpp::STT_OBJECT,
4290                                     elfcpp::STB_LOCAL,
4291                                     elfcpp::STV_HIDDEN, 0,
4292                                     false, false);
4293
4294       // If there are any IRELATIVE relocations, they get GOT entries
4295       // in .got.plt after the jump slot entries.
4296       this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT");
4297       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4298                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4299                                       this->got_irelative_,
4300                                       got_order, is_got_relro);
4301
4302     }
4303   return this->got_;
4304 }
4305
4306 // Get the dynamic reloc section, creating it if necessary.
4307
4308 template<bool big_endian>
4309 typename Target_arm<big_endian>::Reloc_section*
4310 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4311 {
4312   if (this->rel_dyn_ == NULL)
4313     {
4314       gold_assert(layout != NULL);
4315       // Create both relocation sections in the same place, so as to ensure
4316       // their relative order in the output section.
4317       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4318       this->rel_irelative_ = new Reloc_section(false);
4319       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4320                                       elfcpp::SHF_ALLOC, this->rel_dyn_,
4321                                       ORDER_DYNAMIC_RELOCS, false);
4322       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4323                                       elfcpp::SHF_ALLOC, this->rel_irelative_,
4324                                       ORDER_DYNAMIC_RELOCS, false);
4325     }
4326   return this->rel_dyn_;
4327 }
4328
4329
4330 // Get the section to use for IRELATIVE relocs, creating it if necessary.  These
4331 // go in .rela.dyn, but only after all other dynamic relocations.  They need to
4332 // follow the other dynamic relocations so that they can refer to global
4333 // variables initialized by those relocs.
4334
4335 template<bool big_endian>
4336 typename Target_arm<big_endian>::Reloc_section*
4337 Target_arm<big_endian>::rel_irelative_section(Layout* layout)
4338 {
4339   if (this->rel_irelative_ == NULL)
4340     {
4341       // Delegate the creation to rel_dyn_section so as to ensure their order in
4342       // the output section.
4343       this->rel_dyn_section(layout);
4344       gold_assert(this->rel_irelative_ != NULL
4345                   && (this->rel_dyn_->output_section()
4346                       == this->rel_irelative_->output_section()));
4347     }
4348   return this->rel_irelative_;
4349 }
4350
4351
4352 // Insn_template methods.
4353
4354 // Return byte size of an instruction template.
4355
4356 size_t
4357 Insn_template::size() const
4358 {
4359   switch (this->type())
4360     {
4361     case THUMB16_TYPE:
4362     case THUMB16_SPECIAL_TYPE:
4363       return 2;
4364     case ARM_TYPE:
4365     case THUMB32_TYPE:
4366     case DATA_TYPE:
4367       return 4;
4368     default:
4369       gold_unreachable();
4370     }
4371 }
4372
4373 // Return alignment of an instruction template.
4374
4375 unsigned
4376 Insn_template::alignment() const
4377 {
4378   switch (this->type())
4379     {
4380     case THUMB16_TYPE:
4381     case THUMB16_SPECIAL_TYPE:
4382     case THUMB32_TYPE:
4383       return 2;
4384     case ARM_TYPE:
4385     case DATA_TYPE:
4386       return 4;
4387     default:
4388       gold_unreachable();
4389     }
4390 }
4391
4392 // Stub_template methods.
4393
4394 Stub_template::Stub_template(
4395     Stub_type type, const Insn_template* insns,
4396      size_t insn_count)
4397   : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4398     entry_in_thumb_mode_(false), relocs_()
4399 {
4400   off_t offset = 0;
4401
4402   // Compute byte size and alignment of stub template.
4403   for (size_t i = 0; i < insn_count; i++)
4404     {
4405       unsigned insn_alignment = insns[i].alignment();
4406       size_t insn_size = insns[i].size();
4407       gold_assert((offset & (insn_alignment - 1)) == 0);
4408       this->alignment_ = std::max(this->alignment_, insn_alignment);
4409       switch (insns[i].type())
4410         {
4411         case Insn_template::THUMB16_TYPE:
4412         case Insn_template::THUMB16_SPECIAL_TYPE:
4413           if (i == 0)
4414             this->entry_in_thumb_mode_ = true;
4415           break;
4416
4417         case Insn_template::THUMB32_TYPE:
4418           if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4419             this->relocs_.push_back(Reloc(i, offset));
4420           if (i == 0)
4421             this->entry_in_thumb_mode_ = true;
4422           break;
4423
4424         case Insn_template::ARM_TYPE:
4425           // Handle cases where the target is encoded within the
4426           // instruction.
4427           if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4428             this->relocs_.push_back(Reloc(i, offset));
4429           break;
4430
4431         case Insn_template::DATA_TYPE:
4432           // Entry point cannot be data.
4433           gold_assert(i != 0);
4434           this->relocs_.push_back(Reloc(i, offset));
4435           break;
4436
4437         default:
4438           gold_unreachable();
4439         }
4440       offset += insn_size;
4441     }
4442   this->size_ = offset;
4443 }
4444
4445 // Stub methods.
4446
4447 // Template to implement do_write for a specific target endianness.
4448
4449 template<bool big_endian>
4450 void inline
4451 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4452 {
4453   const Stub_template* stub_template = this->stub_template();
4454   const Insn_template* insns = stub_template->insns();
4455
4456   // FIXME:  We do not handle BE8 encoding yet.
4457   unsigned char* pov = view;
4458   for (size_t i = 0; i < stub_template->insn_count(); i++)
4459     {
4460       switch (insns[i].type())
4461         {
4462         case Insn_template::THUMB16_TYPE:
4463           elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4464           break;
4465         case Insn_template::THUMB16_SPECIAL_TYPE:
4466           elfcpp::Swap<16, big_endian>::writeval(
4467               pov,
4468               this->thumb16_special(i));
4469           break;
4470         case Insn_template::THUMB32_TYPE:
4471           {
4472             uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4473             uint32_t lo = insns[i].data() & 0xffff;
4474             elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4475             elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4476           }
4477           break;
4478         case Insn_template::ARM_TYPE:
4479         case Insn_template::DATA_TYPE:
4480           elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4481           break;
4482         default:
4483           gold_unreachable();
4484         }
4485       pov += insns[i].size();
4486     }
4487   gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4488 }
4489
4490 // Reloc_stub::Key methods.
4491
4492 // Dump a Key as a string for debugging.
4493
4494 std::string
4495 Reloc_stub::Key::name() const
4496 {
4497   if (this->r_sym_ == invalid_index)
4498     {
4499       // Global symbol key name
4500       // <stub-type>:<symbol name>:<addend>.
4501       const std::string sym_name = this->u_.symbol->name();
4502       // We need to print two hex number and two colons.  So just add 100 bytes
4503       // to the symbol name size.
4504       size_t len = sym_name.size() + 100;
4505       char* buffer = new char[len];
4506       int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4507                        sym_name.c_str(), this->addend_);
4508       gold_assert(c > 0 && c < static_cast<int>(len));
4509       delete[] buffer;
4510       return std::string(buffer);
4511     }
4512   else
4513     {
4514       // local symbol key name
4515       // <stub-type>:<object>:<r_sym>:<addend>.
4516       const size_t len = 200;
4517       char buffer[len];
4518       int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4519                        this->u_.relobj, this->r_sym_, this->addend_);
4520       gold_assert(c > 0 && c < static_cast<int>(len));
4521       return std::string(buffer);
4522     }
4523 }
4524
4525 // Reloc_stub methods.
4526
4527 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4528 // LOCATION to DESTINATION.
4529 // This code is based on the arm_type_of_stub function in
4530 // bfd/elf32-arm.c.  We have changed the interface a little to keep the Stub
4531 // class simple.
4532
4533 Stub_type
4534 Reloc_stub::stub_type_for_reloc(
4535    unsigned int r_type,
4536    Arm_address location,
4537    Arm_address destination,
4538    bool target_is_thumb)
4539 {
4540   Stub_type stub_type = arm_stub_none;
4541
4542   // This is a bit ugly but we want to avoid using a templated class for
4543   // big and little endianities.
4544   bool may_use_blx;
4545   bool should_force_pic_veneer = parameters->options().pic_veneer();
4546   bool thumb2;
4547   bool thumb_only;
4548   if (parameters->target().is_big_endian())
4549     {
4550       const Target_arm<true>* big_endian_target =
4551         Target_arm<true>::default_target();
4552       may_use_blx = big_endian_target->may_use_v5t_interworking();
4553       should_force_pic_veneer |= big_endian_target->should_force_pic_veneer();
4554       thumb2 = big_endian_target->using_thumb2();
4555       thumb_only = big_endian_target->using_thumb_only();
4556     }
4557   else
4558     {
4559       const Target_arm<false>* little_endian_target =
4560         Target_arm<false>::default_target();
4561       may_use_blx = little_endian_target->may_use_v5t_interworking();
4562       should_force_pic_veneer |=
4563         little_endian_target->should_force_pic_veneer();
4564       thumb2 = little_endian_target->using_thumb2();
4565       thumb_only = little_endian_target->using_thumb_only();
4566     }
4567
4568   int64_t branch_offset;
4569   bool output_is_position_independent =
4570       parameters->options().output_is_position_independent();
4571   if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4572     {
4573       // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4574       // base address (instruction address + 4).
4575       if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4576         destination = Bits<32>::bit_select32(destination, location, 0x2);
4577       branch_offset = static_cast<int64_t>(destination) - location;
4578
4579       // Handle cases where:
4580       // - this call goes too far (different Thumb/Thumb2 max
4581       //   distance)
4582       // - it's a Thumb->Arm call and blx is not available, or it's a
4583       //   Thumb->Arm branch (not bl). A stub is needed in this case.
4584       if ((!thumb2
4585             && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4586                 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4587           || (thumb2
4588               && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4589                   || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4590           || ((!target_is_thumb)
4591               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4592                   || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4593         {
4594           if (target_is_thumb)
4595             {
4596               // Thumb to thumb.
4597               if (!thumb_only)
4598                 {
4599                   stub_type = (output_is_position_independent
4600                                || should_force_pic_veneer)
4601                     // PIC stubs.
4602                     ? ((may_use_blx
4603                         && (r_type == elfcpp::R_ARM_THM_CALL))
4604                        // V5T and above. Stub starts with ARM code, so
4605                        // we must be able to switch mode before
4606                        // reaching it, which is only possible for 'bl'
4607                        // (ie R_ARM_THM_CALL relocation).
4608                        ? arm_stub_long_branch_any_thumb_pic
4609                        // On V4T, use Thumb code only.
4610                        : arm_stub_long_branch_v4t_thumb_thumb_pic)
4611
4612                     // non-PIC stubs.
4613                     : ((may_use_blx
4614                         && (r_type == elfcpp::R_ARM_THM_CALL))
4615                        ? arm_stub_long_branch_any_any // V5T and above.
4616                        : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4617                 }
4618               else
4619                 {
4620                   stub_type = (output_is_position_independent
4621                                || should_force_pic_veneer)
4622                     ? arm_stub_long_branch_thumb_only_pic       // PIC stub.
4623                     : arm_stub_long_branch_thumb_only;  // non-PIC stub.
4624                 }
4625             }
4626           else
4627             {
4628               // Thumb to arm.
4629
4630               // FIXME: We should check that the input section is from an
4631               // object that has interwork enabled.
4632
4633               stub_type = (output_is_position_independent
4634                            || should_force_pic_veneer)
4635                 // PIC stubs.
4636                 ? ((may_use_blx
4637                     && (r_type == elfcpp::R_ARM_THM_CALL))
4638                    ? arm_stub_long_branch_any_arm_pic   // V5T and above.
4639                    : arm_stub_long_branch_v4t_thumb_arm_pic)    // V4T.
4640
4641                 // non-PIC stubs.
4642                 : ((may_use_blx
4643                     && (r_type == elfcpp::R_ARM_THM_CALL))
4644                    ? arm_stub_long_branch_any_any       // V5T and above.
4645                    : arm_stub_long_branch_v4t_thumb_arm);       // V4T.
4646
4647               // Handle v4t short branches.
4648               if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4649                   && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4650                   && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4651                 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4652             }
4653         }
4654     }
4655   else if (r_type == elfcpp::R_ARM_CALL
4656            || r_type == elfcpp::R_ARM_JUMP24
4657            || r_type == elfcpp::R_ARM_PLT32)
4658     {
4659       branch_offset = static_cast<int64_t>(destination) - location;
4660       if (target_is_thumb)
4661         {
4662           // Arm to thumb.
4663
4664           // FIXME: We should check that the input section is from an
4665           // object that has interwork enabled.
4666
4667           // We have an extra 2-bytes reach because of
4668           // the mode change (bit 24 (H) of BLX encoding).
4669           if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4670               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4671               || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4672               || (r_type == elfcpp::R_ARM_JUMP24)
4673               || (r_type == elfcpp::R_ARM_PLT32))
4674             {
4675               stub_type = (output_is_position_independent
4676                            || should_force_pic_veneer)
4677                 // PIC stubs.
4678                 ? (may_use_blx
4679                    ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4680                    : arm_stub_long_branch_v4t_arm_thumb_pic)    // V4T stub.
4681
4682                 // non-PIC stubs.
4683                 : (may_use_blx
4684                    ? arm_stub_long_branch_any_any       // V5T and above.
4685                    : arm_stub_long_branch_v4t_arm_thumb);       // V4T.
4686             }
4687         }
4688       else
4689         {
4690           // Arm to arm.
4691           if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4692               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4693             {
4694               stub_type = (output_is_position_independent
4695                            || should_force_pic_veneer)
4696                 ? arm_stub_long_branch_any_arm_pic      // PIC stubs.
4697                 : arm_stub_long_branch_any_any;         /// non-PIC.
4698             }
4699         }
4700     }
4701
4702   return stub_type;
4703 }
4704
4705 // Cortex_a8_stub methods.
4706
4707 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4708 // I is the position of the instruction template in the stub template.
4709
4710 uint16_t
4711 Cortex_a8_stub::do_thumb16_special(size_t i)
4712 {
4713   // The only use of this is to copy condition code from a conditional
4714   // branch being worked around to the corresponding conditional branch in
4715   // to the stub.
4716   gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4717               && i == 0);
4718   uint16_t data = this->stub_template()->insns()[i].data();
4719   gold_assert((data & 0xff00U) == 0xd000U);
4720   data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4721   return data;
4722 }
4723
4724 // Stub_factory methods.
4725
4726 Stub_factory::Stub_factory()
4727 {
4728   // The instruction template sequences are declared as static
4729   // objects and initialized first time the constructor runs.
4730
4731   // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4732   // to reach the stub if necessary.
4733   static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4734     {
4735       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4736       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4737                                                 // dcd   R_ARM_ABS32(X)
4738     };
4739
4740   // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4741   // available.
4742   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4743     {
4744       Insn_template::arm_insn(0xe59fc000),      // ldr   ip, [pc, #0]
4745       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4746       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4747                                                 // dcd   R_ARM_ABS32(X)
4748     };
4749
4750   // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4751   static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4752     {
4753       Insn_template::thumb16_insn(0xb401),      // push {r0}
4754       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4755       Insn_template::thumb16_insn(0x4684),      // mov  ip, r0
4756       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4757       Insn_template::thumb16_insn(0x4760),      // bx   ip
4758       Insn_template::thumb16_insn(0xbf00),      // nop
4759       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4760                                                 // dcd  R_ARM_ABS32(X)
4761     };
4762
4763   // V4T Thumb -> Thumb long branch stub. Using the stack is not
4764   // allowed.
4765   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4766     {
4767       Insn_template::thumb16_insn(0x4778),      // bx   pc
4768       Insn_template::thumb16_insn(0x46c0),      // nop
4769       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4770       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4771       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4772                                                 // dcd  R_ARM_ABS32(X)
4773     };
4774
4775   // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4776   // available.
4777   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4778     {
4779       Insn_template::thumb16_insn(0x4778),      // bx   pc
4780       Insn_template::thumb16_insn(0x46c0),      // nop
4781       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4782       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4783                                                 // dcd   R_ARM_ABS32(X)
4784     };
4785
4786   // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4787   // one, when the destination is close enough.
4788   static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4789     {
4790       Insn_template::thumb16_insn(0x4778),              // bx   pc
4791       Insn_template::thumb16_insn(0x46c0),              // nop
4792       Insn_template::arm_rel_insn(0xea000000, -8),      // b    (X-8)
4793     };
4794
4795   // ARM/Thumb -> ARM long branch stub, PIC.  On V5T and above, use
4796   // blx to reach the stub if necessary.
4797   static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4798     {
4799       Insn_template::arm_insn(0xe59fc000),      // ldr   r12, [pc]
4800       Insn_template::arm_insn(0xe08ff00c),      // add   pc, pc, ip
4801       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4802                                                 // dcd   R_ARM_REL32(X-4)
4803     };
4804
4805   // ARM/Thumb -> Thumb long branch stub, PIC.  On V5T and above, use
4806   // blx to reach the stub if necessary.  We can not add into pc;
4807   // it is not guaranteed to mode switch (different in ARMv6 and
4808   // ARMv7).
4809   static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4810     {
4811       Insn_template::arm_insn(0xe59fc004),      // ldr   r12, [pc, #4]
4812       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4813       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4814       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4815                                                 // dcd   R_ARM_REL32(X)
4816     };
4817
4818   // V4T ARM -> ARM long branch stub, PIC.
4819   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4820     {
4821       Insn_template::arm_insn(0xe59fc004),      // ldr   ip, [pc, #4]
4822       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4823       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4824       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4825                                                 // dcd   R_ARM_REL32(X)
4826     };
4827
4828   // V4T Thumb -> ARM long branch stub, PIC.
4829   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4830     {
4831       Insn_template::thumb16_insn(0x4778),      // bx   pc
4832       Insn_template::thumb16_insn(0x46c0),      // nop
4833       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4834       Insn_template::arm_insn(0xe08cf00f),      // add  pc, ip, pc
4835       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4836                                                 // dcd  R_ARM_REL32(X)
4837     };
4838
4839   // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4840   // architectures.
4841   static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4842     {
4843       Insn_template::thumb16_insn(0xb401),      // push {r0}
4844       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4845       Insn_template::thumb16_insn(0x46fc),      // mov  ip, pc
4846       Insn_template::thumb16_insn(0x4484),      // add  ip, r0
4847       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4848       Insn_template::thumb16_insn(0x4760),      // bx   ip
4849       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4850                                                 // dcd  R_ARM_REL32(X)
4851     };
4852
4853   // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4854   // allowed.
4855   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4856     {
4857       Insn_template::thumb16_insn(0x4778),      // bx   pc
4858       Insn_template::thumb16_insn(0x46c0),      // nop
4859       Insn_template::arm_insn(0xe59fc004),      // ldr  ip, [pc, #4]
4860       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4861       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4862       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4863                                                 // dcd  R_ARM_REL32(X)
4864     };
4865
4866   // Cortex-A8 erratum-workaround stubs.
4867
4868   // Stub used for conditional branches (which may be beyond +/-1MB away,
4869   // so we can't use a conditional branch to reach this stub).
4870
4871   // original code:
4872   //
4873   //    b<cond> X
4874   // after:
4875   //
4876   static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4877     {
4878       Insn_template::thumb16_bcond_insn(0xd001),        //      b<cond>.n true
4879       Insn_template::thumb32_b_insn(0xf000b800, -4),    //      b.w after
4880       Insn_template::thumb32_b_insn(0xf000b800, -4)     // true:
4881                                                         //      b.w X
4882     };
4883
4884   // Stub used for b.w and bl.w instructions.
4885
4886   static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4887     {
4888       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4889     };
4890
4891   static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4892     {
4893       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4894     };
4895
4896   // Stub used for Thumb-2 blx.w instructions.  We modified the original blx.w
4897   // instruction (which switches to ARM mode) to point to this stub.  Jump to
4898   // the real destination using an ARM-mode branch.
4899   static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4900     {
4901       Insn_template::arm_rel_insn(0xea000000, -8)       // b dest
4902     };
4903
4904   // Stub used to provide an interworking for R_ARM_V4BX relocation
4905   // (bx r[n] instruction).
4906   static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4907     {
4908       Insn_template::arm_insn(0xe3100001),              // tst   r<n>, #1
4909       Insn_template::arm_insn(0x01a0f000),              // moveq pc, r<n>
4910       Insn_template::arm_insn(0xe12fff10)               // bx    r<n>
4911     };
4912
4913   // Fill in the stub template look-up table.  Stub templates are constructed
4914   // per instance of Stub_factory for fast look-up without locking
4915   // in a thread-enabled environment.
4916
4917   this->stub_templates_[arm_stub_none] =
4918     new Stub_template(arm_stub_none, NULL, 0);
4919
4920 #define DEF_STUB(x)     \
4921   do \
4922     { \
4923       size_t array_size \
4924         = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4925       Stub_type type = arm_stub_##x; \
4926       this->stub_templates_[type] = \
4927         new Stub_template(type, elf32_arm_stub_##x, array_size); \
4928     } \
4929   while (0);
4930
4931   DEF_STUBS
4932 #undef DEF_STUB
4933 }
4934
4935 // Stub_table methods.
4936
4937 // Remove all Cortex-A8 stub.
4938
4939 template<bool big_endian>
4940 void
4941 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4942 {
4943   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4944        p != this->cortex_a8_stubs_.end();
4945        ++p)
4946     delete p->second;
4947   this->cortex_a8_stubs_.clear();
4948 }
4949
4950 // Relocate one stub.  This is a helper for Stub_table::relocate_stubs().
4951
4952 template<bool big_endian>
4953 void
4954 Stub_table<big_endian>::relocate_stub(
4955     Stub* stub,
4956     const Relocate_info<32, big_endian>* relinfo,
4957     Target_arm<big_endian>* arm_target,
4958     Output_section* output_section,
4959     unsigned char* view,
4960     Arm_address address,
4961     section_size_type view_size)
4962 {
4963   const Stub_template* stub_template = stub->stub_template();
4964   if (stub_template->reloc_count() != 0)
4965     {
4966       // Adjust view to cover the stub only.
4967       section_size_type offset = stub->offset();
4968       section_size_type stub_size = stub_template->size();
4969       gold_assert(offset + stub_size <= view_size);
4970
4971       arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4972                                 address + offset, stub_size);
4973     }
4974 }
4975
4976 // Relocate all stubs in this stub table.
4977
4978 template<bool big_endian>
4979 void
4980 Stub_table<big_endian>::relocate_stubs(
4981     const Relocate_info<32, big_endian>* relinfo,
4982     Target_arm<big_endian>* arm_target,
4983     Output_section* output_section,
4984     unsigned char* view,
4985     Arm_address address,
4986     section_size_type view_size)
4987 {
4988   // If we are passed a view bigger than the stub table's.  we need to
4989   // adjust the view.
4990   gold_assert(address == this->address()
4991               && (view_size
4992                   == static_cast<section_size_type>(this->data_size())));
4993
4994   // Relocate all relocation stubs.
4995   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4996       p != this->reloc_stubs_.end();
4997       ++p)
4998     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4999                         address, view_size);
5000
5001   // Relocate all Cortex-A8 stubs.
5002   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
5003        p != this->cortex_a8_stubs_.end();
5004        ++p)
5005     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
5006                         address, view_size);
5007
5008   // Relocate all ARM V4BX stubs.
5009   for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
5010        p != this->arm_v4bx_stubs_.end();
5011        ++p)
5012     {
5013       if (*p != NULL)
5014         this->relocate_stub(*p, relinfo, arm_target, output_section, view,
5015                             address, view_size);
5016     }
5017 }
5018
5019 // Write out the stubs to file.
5020
5021 template<bool big_endian>
5022 void
5023 Stub_table<big_endian>::do_write(Output_file* of)
5024 {
5025   off_t offset = this->offset();
5026   const section_size_type oview_size =
5027     convert_to_section_size_type(this->data_size());
5028   unsigned char* const oview = of->get_output_view(offset, oview_size);
5029
5030   // Write relocation stubs.
5031   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
5032       p != this->reloc_stubs_.end();
5033       ++p)
5034     {
5035       Reloc_stub* stub = p->second;
5036       Arm_address address = this->address() + stub->offset();
5037       gold_assert(address
5038                   == align_address(address,
5039                                    stub->stub_template()->alignment()));
5040       stub->write(oview + stub->offset(), stub->stub_template()->size(),
5041                   big_endian);
5042     }
5043
5044   // Write Cortex-A8 stubs.
5045   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5046        p != this->cortex_a8_stubs_.end();
5047        ++p)
5048     {
5049       Cortex_a8_stub* stub = p->second;
5050       Arm_address address = this->address() + stub->offset();
5051       gold_assert(address
5052                   == align_address(address,
5053                                    stub->stub_template()->alignment()));
5054       stub->write(oview + stub->offset(), stub->stub_template()->size(),
5055                   big_endian);
5056     }
5057
5058   // Write ARM V4BX relocation stubs.
5059   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5060        p != this->arm_v4bx_stubs_.end();
5061        ++p)
5062     {
5063       if (*p == NULL)
5064         continue;
5065
5066       Arm_address address = this->address() + (*p)->offset();
5067       gold_assert(address
5068                   == align_address(address,
5069                                    (*p)->stub_template()->alignment()));
5070       (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
5071                   big_endian);
5072     }
5073
5074   of->write_output_view(this->offset(), oview_size, oview);
5075 }
5076
5077 // Update the data size and address alignment of the stub table at the end
5078 // of a relaxation pass.   Return true if either the data size or the
5079 // alignment changed in this relaxation pass.
5080
5081 template<bool big_endian>
5082 bool
5083 Stub_table<big_endian>::update_data_size_and_addralign()
5084 {
5085   // Go over all stubs in table to compute data size and address alignment.
5086   off_t size = this->reloc_stubs_size_;
5087   unsigned addralign = this->reloc_stubs_addralign_;
5088
5089   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5090        p != this->cortex_a8_stubs_.end();
5091        ++p)
5092     {
5093       const Stub_template* stub_template = p->second->stub_template();
5094       addralign = std::max(addralign, stub_template->alignment());
5095       size = (align_address(size, stub_template->alignment())
5096               + stub_template->size());
5097     }
5098
5099   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5100        p != this->arm_v4bx_stubs_.end();
5101        ++p)
5102     {
5103       if (*p == NULL)
5104         continue;
5105
5106       const Stub_template* stub_template = (*p)->stub_template();
5107       addralign = std::max(addralign, stub_template->alignment());
5108       size = (align_address(size, stub_template->alignment())
5109               + stub_template->size());
5110     }
5111
5112   // Check if either data size or alignment changed in this pass.
5113   // Update prev_data_size_ and prev_addralign_.  These will be used
5114   // as the current data size and address alignment for the next pass.
5115   bool changed = size != this->prev_data_size_;
5116   this->prev_data_size_ = size;
5117
5118   if (addralign != this->prev_addralign_)
5119     changed = true;
5120   this->prev_addralign_ = addralign;
5121
5122   return changed;
5123 }
5124
5125 // Finalize the stubs.  This sets the offsets of the stubs within the stub
5126 // table.  It also marks all input sections needing Cortex-A8 workaround.
5127
5128 template<bool big_endian>
5129 void
5130 Stub_table<big_endian>::finalize_stubs()
5131 {
5132   off_t off = this->reloc_stubs_size_;
5133   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5134        p != this->cortex_a8_stubs_.end();
5135        ++p)
5136     {
5137       Cortex_a8_stub* stub = p->second;
5138       const Stub_template* stub_template = stub->stub_template();
5139       uint64_t stub_addralign = stub_template->alignment();
5140       off = align_address(off, stub_addralign);
5141       stub->set_offset(off);
5142       off += stub_template->size();
5143
5144       // Mark input section so that we can determine later if a code section
5145       // needs the Cortex-A8 workaround quickly.
5146       Arm_relobj<big_endian>* arm_relobj =
5147         Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5148       arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5149     }
5150
5151   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5152       p != this->arm_v4bx_stubs_.end();
5153       ++p)
5154     {
5155       if (*p == NULL)
5156         continue;
5157
5158       const Stub_template* stub_template = (*p)->stub_template();
5159       uint64_t stub_addralign = stub_template->alignment();
5160       off = align_address(off, stub_addralign);
5161       (*p)->set_offset(off);
5162       off += stub_template->size();
5163     }
5164
5165   gold_assert(off <= this->prev_data_size_);
5166 }
5167
5168 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5169 // and VIEW_ADDRESS + VIEW_SIZE - 1.  VIEW points to the mapped address
5170 // of the address range seen by the linker.
5171
5172 template<bool big_endian>
5173 void
5174 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5175     Target_arm<big_endian>* arm_target,
5176     unsigned char* view,
5177     Arm_address view_address,
5178     section_size_type view_size)
5179 {
5180   // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5181   for (Cortex_a8_stub_list::const_iterator p =
5182          this->cortex_a8_stubs_.lower_bound(view_address);
5183        ((p != this->cortex_a8_stubs_.end())
5184         && (p->first < (view_address + view_size)));
5185        ++p)
5186     {
5187       // We do not store the THUMB bit in the LSB of either the branch address
5188       // or the stub offset.  There is no need to strip the LSB.
5189       Arm_address branch_address = p->first;
5190       const Cortex_a8_stub* stub = p->second;
5191       Arm_address stub_address = this->address() + stub->offset();
5192
5193       // Offset of the branch instruction relative to this view.
5194       section_size_type offset =
5195         convert_to_section_size_type(branch_address - view_address);
5196       gold_assert((offset + 4) <= view_size);
5197
5198       arm_target->apply_cortex_a8_workaround(stub, stub_address,
5199                                              view + offset, branch_address);
5200     }
5201 }
5202
5203 // Arm_input_section methods.
5204
5205 // Initialize an Arm_input_section.
5206
5207 template<bool big_endian>
5208 void
5209 Arm_input_section<big_endian>::init()
5210 {
5211   Relobj* relobj = this->relobj();
5212   unsigned int shndx = this->shndx();
5213
5214   // We have to cache original size, alignment and contents to avoid locking
5215   // the original file.
5216   this->original_addralign_ =
5217     convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5218
5219   // This is not efficient but we expect only a small number of relaxed
5220   // input sections for stubs.
5221   section_size_type section_size;
5222   const unsigned char* section_contents =
5223     relobj->section_contents(shndx, &section_size, false);
5224   this->original_size_ =
5225     convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5226
5227   gold_assert(this->original_contents_ == NULL);
5228   this->original_contents_ = new unsigned char[section_size];
5229   memcpy(this->original_contents_, section_contents, section_size);
5230
5231   // We want to make this look like the original input section after
5232   // output sections are finalized.
5233   Output_section* os = relobj->output_section(shndx);
5234   off_t offset = relobj->output_section_offset(shndx);
5235   gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5236   this->set_address(os->address() + offset);
5237   this->set_file_offset(os->offset() + offset);
5238
5239   this->set_current_data_size(this->original_size_);
5240   this->finalize_data_size();
5241 }
5242
5243 template<bool big_endian>
5244 void
5245 Arm_input_section<big_endian>::do_write(Output_file* of)
5246 {
5247   // We have to write out the original section content.
5248   gold_assert(this->original_contents_ != NULL);
5249   of->write(this->offset(), this->original_contents_,
5250             this->original_size_);
5251
5252   // If this owns a stub table and it is not empty, write it.
5253   if (this->is_stub_table_owner() && !this->stub_table_->empty())
5254     this->stub_table_->write(of);
5255 }
5256
5257 // Finalize data size.
5258
5259 template<bool big_endian>
5260 void
5261 Arm_input_section<big_endian>::set_final_data_size()
5262 {
5263   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5264
5265   if (this->is_stub_table_owner())
5266     {
5267       this->stub_table_->finalize_data_size();
5268       off = align_address(off, this->stub_table_->addralign());
5269       off += this->stub_table_->data_size();
5270     }
5271   this->set_data_size(off);
5272 }
5273
5274 // Reset address and file offset.
5275
5276 template<bool big_endian>
5277 void
5278 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5279 {
5280   // Size of the original input section contents.
5281   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5282
5283   // If this is a stub table owner, account for the stub table size.
5284   if (this->is_stub_table_owner())
5285     {
5286       Stub_table<big_endian>* stub_table = this->stub_table_;
5287
5288       // Reset the stub table's address and file offset.  The
5289       // current data size for child will be updated after that.
5290       stub_table_->reset_address_and_file_offset();
5291       off = align_address(off, stub_table_->addralign());
5292       off += stub_table->current_data_size();
5293     }
5294
5295   this->set_current_data_size(off);
5296 }
5297
5298 // Arm_exidx_cantunwind methods.
5299
5300 // Write this to Output file OF for a fixed endianness.
5301
5302 template<bool big_endian>
5303 void
5304 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5305 {
5306   off_t offset = this->offset();
5307   const section_size_type oview_size = 8;
5308   unsigned char* const oview = of->get_output_view(offset, oview_size);
5309
5310   Output_section* os = this->relobj_->output_section(this->shndx_);
5311   gold_assert(os != NULL);
5312
5313   Arm_relobj<big_endian>* arm_relobj =
5314     Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5315   Arm_address output_offset =
5316     arm_relobj->get_output_section_offset(this->shndx_);
5317   Arm_address section_start;
5318   section_size_type section_size;
5319
5320   // Find out the end of the text section referred by this.
5321   if (output_offset != Arm_relobj<big_endian>::invalid_address)
5322     {
5323       section_start = os->address() + output_offset;
5324       const Arm_exidx_input_section* exidx_input_section =
5325         arm_relobj->exidx_input_section_by_link(this->shndx_);
5326       gold_assert(exidx_input_section != NULL);
5327       section_size =
5328         convert_to_section_size_type(exidx_input_section->text_size());
5329     }
5330   else
5331     {
5332       // Currently this only happens for a relaxed section.
5333       const Output_relaxed_input_section* poris =
5334         os->find_relaxed_input_section(this->relobj_, this->shndx_);
5335       gold_assert(poris != NULL);
5336       section_start = poris->address();
5337       section_size = convert_to_section_size_type(poris->data_size());
5338     }
5339
5340   // We always append this to the end of an EXIDX section.
5341   Arm_address output_address = section_start + section_size;
5342
5343   // Write out the entry.  The first word either points to the beginning
5344   // or after the end of a text section.  The second word is the special
5345   // EXIDX_CANTUNWIND value.
5346   uint32_t prel31_offset = output_address - this->address();
5347   if (Bits<31>::has_overflow32(offset))
5348     gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5349   elfcpp::Swap_unaligned<32, big_endian>::writeval(oview,
5350                                                    prel31_offset & 0x7fffffffU);
5351   elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4,
5352                                                    elfcpp::EXIDX_CANTUNWIND);
5353
5354   of->write_output_view(this->offset(), oview_size, oview);
5355 }
5356
5357 // Arm_exidx_merged_section methods.
5358
5359 // Constructor for Arm_exidx_merged_section.
5360 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5361 // SECTION_OFFSET_MAP points to a section offset map describing how
5362 // parts of the input section are mapped to output.  DELETED_BYTES is
5363 // the number of bytes deleted from the EXIDX input section.
5364
5365 Arm_exidx_merged_section::Arm_exidx_merged_section(
5366     const Arm_exidx_input_section& exidx_input_section,
5367     const Arm_exidx_section_offset_map& section_offset_map,
5368     uint32_t deleted_bytes)
5369   : Output_relaxed_input_section(exidx_input_section.relobj(),
5370                                  exidx_input_section.shndx(),
5371                                  exidx_input_section.addralign()),
5372     exidx_input_section_(exidx_input_section),
5373     section_offset_map_(section_offset_map)
5374 {
5375   // If we retain or discard the whole EXIDX input section,  we would
5376   // not be here.
5377   gold_assert(deleted_bytes != 0
5378               && deleted_bytes != this->exidx_input_section_.size());
5379
5380   // Fix size here so that we do not need to implement set_final_data_size.
5381   uint32_t size = exidx_input_section.size() - deleted_bytes;
5382   this->set_data_size(size);
5383   this->fix_data_size();
5384
5385   // Allocate buffer for section contents and build contents.
5386   this->section_contents_ = new unsigned char[size];
5387 }
5388
5389 // Build the contents of a merged EXIDX output section.
5390
5391 void
5392 Arm_exidx_merged_section::build_contents(
5393     const unsigned char* original_contents,
5394     section_size_type original_size)
5395 {
5396   // Go over spans of input offsets and write only those that are not
5397   // discarded.
5398   section_offset_type in_start = 0;
5399   section_offset_type out_start = 0;
5400   section_offset_type in_max =
5401     convert_types<section_offset_type>(original_size);
5402   section_offset_type out_max =
5403     convert_types<section_offset_type>(this->data_size());
5404   for (Arm_exidx_section_offset_map::const_iterator p =
5405         this->section_offset_map_.begin();
5406       p != this->section_offset_map_.end();
5407       ++p)
5408     {
5409       section_offset_type in_end = p->first;
5410       gold_assert(in_end >= in_start);
5411       section_offset_type out_end = p->second;
5412       size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5413       if (out_end != -1)
5414         {
5415           size_t out_chunk_size =
5416             convert_types<size_t>(out_end - out_start + 1);
5417
5418           gold_assert(out_chunk_size == in_chunk_size
5419                       && in_end < in_max && out_end < out_max);
5420
5421           memcpy(this->section_contents_ + out_start,
5422                  original_contents + in_start,
5423                  out_chunk_size);
5424           out_start += out_chunk_size;
5425         }
5426       in_start += in_chunk_size;
5427     }
5428 }
5429
5430 // Given an input OBJECT, an input section index SHNDX within that
5431 // object, and an OFFSET relative to the start of that input
5432 // section, return whether or not the corresponding offset within
5433 // the output section is known.  If this function returns true, it
5434 // sets *POUTPUT to the output offset.  The value -1 indicates that
5435 // this input offset is being discarded.
5436
5437 bool
5438 Arm_exidx_merged_section::do_output_offset(
5439     const Relobj* relobj,
5440     unsigned int shndx,
5441     section_offset_type offset,
5442     section_offset_type* poutput) const
5443 {
5444   // We only handle offsets for the original EXIDX input section.
5445   if (relobj != this->exidx_input_section_.relobj()
5446       || shndx != this->exidx_input_section_.shndx())
5447     return false;
5448
5449   section_offset_type section_size =
5450     convert_types<section_offset_type>(this->exidx_input_section_.size());
5451   if (offset < 0 || offset >= section_size)
5452     // Input offset is out of valid range.
5453     *poutput = -1;
5454   else
5455     {
5456       // We need to look up the section offset map to determine the output
5457       // offset.  Find the reference point in map that is first offset
5458       // bigger than or equal to this offset.
5459       Arm_exidx_section_offset_map::const_iterator p =
5460         this->section_offset_map_.lower_bound(offset);
5461
5462       // The section offset maps are build such that this should not happen if
5463       // input offset is in the valid range.
5464       gold_assert(p != this->section_offset_map_.end());
5465
5466       // We need to check if this is dropped.
5467      section_offset_type ref = p->first;
5468      section_offset_type mapped_ref = p->second;
5469
5470       if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5471         // Offset is present in output.
5472         *poutput = mapped_ref + (offset - ref);
5473       else
5474         // Offset is discarded owing to EXIDX entry merging.
5475         *poutput = -1;
5476     }
5477
5478   return true;
5479 }
5480
5481 // Write this to output file OF.
5482
5483 void
5484 Arm_exidx_merged_section::do_write(Output_file* of)
5485 {
5486   off_t offset = this->offset();
5487   const section_size_type oview_size = this->data_size();
5488   unsigned char* const oview = of->get_output_view(offset, oview_size);
5489
5490   Output_section* os = this->relobj()->output_section(this->shndx());
5491   gold_assert(os != NULL);
5492
5493   memcpy(oview, this->section_contents_, oview_size);
5494   of->write_output_view(this->offset(), oview_size, oview);
5495 }
5496
5497 // Arm_exidx_fixup methods.
5498
5499 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5500 // is not an EXIDX_CANTUNWIND entry already.  The new EXIDX_CANTUNWIND entry
5501 // points to the end of the last seen EXIDX section.
5502
5503 void
5504 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5505 {
5506   if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5507       && this->last_input_section_ != NULL)
5508     {
5509       Relobj* relobj = this->last_input_section_->relobj();
5510       unsigned int text_shndx = this->last_input_section_->link();
5511       Arm_exidx_cantunwind* cantunwind =
5512         new Arm_exidx_cantunwind(relobj, text_shndx);
5513       this->exidx_output_section_->add_output_section_data(cantunwind);
5514       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5515     }
5516 }
5517
5518 // Process an EXIDX section entry in input.  Return whether this entry
5519 // can be deleted in the output.  SECOND_WORD in the second word of the
5520 // EXIDX entry.
5521
5522 bool
5523 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5524 {
5525   bool delete_entry;
5526   if (second_word == elfcpp::EXIDX_CANTUNWIND)
5527     {
5528       // Merge if previous entry is also an EXIDX_CANTUNWIND.
5529       delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5530       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5531     }
5532   else if ((second_word & 0x80000000) != 0)
5533     {
5534       // Inlined unwinding data.  Merge if equal to previous.
5535       delete_entry = (merge_exidx_entries_
5536                       && this->last_unwind_type_ == UT_INLINED_ENTRY
5537                       && this->last_inlined_entry_ == second_word);
5538       this->last_unwind_type_ = UT_INLINED_ENTRY;
5539       this->last_inlined_entry_ = second_word;
5540     }
5541   else
5542     {
5543       // Normal table entry.  In theory we could merge these too,
5544       // but duplicate entries are likely to be much less common.
5545       delete_entry = false;
5546       this->last_unwind_type_ = UT_NORMAL_ENTRY;
5547     }
5548   return delete_entry;
5549 }
5550
5551 // Update the current section offset map during EXIDX section fix-up.
5552 // If there is no map, create one.  INPUT_OFFSET is the offset of a
5553 // reference point, DELETED_BYTES is the number of deleted by in the
5554 // section so far.  If DELETE_ENTRY is true, the reference point and
5555 // all offsets after the previous reference point are discarded.
5556
5557 void
5558 Arm_exidx_fixup::update_offset_map(
5559     section_offset_type input_offset,
5560     section_size_type deleted_bytes,
5561     bool delete_entry)
5562 {
5563   if (this->section_offset_map_ == NULL)
5564     this->section_offset_map_ = new Arm_exidx_section_offset_map();
5565   section_offset_type output_offset;
5566   if (delete_entry)
5567     output_offset = Arm_exidx_input_section::invalid_offset;
5568   else
5569     output_offset = input_offset - deleted_bytes;
5570   (*this->section_offset_map_)[input_offset] = output_offset;
5571 }
5572
5573 // Process EXIDX_INPUT_SECTION for EXIDX entry merging.  Return the number of
5574 // bytes deleted.  SECTION_CONTENTS points to the contents of the EXIDX
5575 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5576 // If some entries are merged, also store a pointer to a newly created
5577 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP.  The caller
5578 // owns the map and is responsible for releasing it after use.
5579
5580 template<bool big_endian>
5581 uint32_t
5582 Arm_exidx_fixup::process_exidx_section(
5583     const Arm_exidx_input_section* exidx_input_section,
5584     const unsigned char* section_contents,
5585     section_size_type section_size,
5586     Arm_exidx_section_offset_map** psection_offset_map)
5587 {
5588   Relobj* relobj = exidx_input_section->relobj();
5589   unsigned shndx = exidx_input_section->shndx();
5590
5591   if ((section_size % 8) != 0)
5592     {
5593       // Something is wrong with this section.  Better not touch it.
5594       gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5595                  relobj->name().c_str(), shndx);
5596       this->last_input_section_ = exidx_input_section;
5597       this->last_unwind_type_ = UT_NONE;
5598       return 0;
5599     }
5600
5601   uint32_t deleted_bytes = 0;
5602   bool prev_delete_entry = false;
5603   gold_assert(this->section_offset_map_ == NULL);
5604
5605   for (section_size_type i = 0; i < section_size; i += 8)
5606     {
5607       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5608       const Valtype* wv =
5609           reinterpret_cast<const Valtype*>(section_contents + i + 4);
5610       uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5611
5612       bool delete_entry = this->process_exidx_entry(second_word);
5613
5614       // Entry deletion causes changes in output offsets.  We use a std::map
5615       // to record these.  And entry (x, y) means input offset x
5616       // is mapped to output offset y.  If y is invalid_offset, then x is
5617       // dropped in the output.  Because of the way std::map::lower_bound
5618       // works, we record the last offset in a region w.r.t to keeping or
5619       // dropping.  If there is no entry (x0, y0) for an input offset x0,
5620       // the output offset y0 of it is determined by the output offset y1 of
5621       // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5622       // in the map.  If y1 is not -1, then y0 = y1 + x0 - x1.  Otherwise, y1
5623       // y0 is also -1.
5624       if (delete_entry != prev_delete_entry && i != 0)
5625         this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5626
5627       // Update total deleted bytes for this entry.
5628       if (delete_entry)
5629         deleted_bytes += 8;
5630
5631       prev_delete_entry = delete_entry;
5632     }
5633
5634   // If section offset map is not NULL, make an entry for the end of
5635   // section.
5636   if (this->section_offset_map_ != NULL)
5637     update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5638
5639   *psection_offset_map = this->section_offset_map_;
5640   this->section_offset_map_ = NULL;
5641   this->last_input_section_ = exidx_input_section;
5642
5643   // Set the first output text section so that we can link the EXIDX output
5644   // section to it.  Ignore any EXIDX input section that is completely merged.
5645   if (this->first_output_text_section_ == NULL
5646       && deleted_bytes != section_size)
5647     {
5648       unsigned int link = exidx_input_section->link();
5649       Output_section* os = relobj->output_section(link);
5650       gold_assert(os != NULL);
5651       this->first_output_text_section_ = os;
5652     }
5653
5654   return deleted_bytes;
5655 }
5656
5657 // Arm_output_section methods.
5658
5659 // Create a stub group for input sections from BEGIN to END.  OWNER
5660 // points to the input section to be the owner a new stub table.
5661
5662 template<bool big_endian>
5663 void
5664 Arm_output_section<big_endian>::create_stub_group(
5665   Input_section_list::const_iterator begin,
5666   Input_section_list::const_iterator end,
5667   Input_section_list::const_iterator owner,
5668   Target_arm<big_endian>* target,
5669   std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5670   const Task* task)
5671 {
5672   // We use a different kind of relaxed section in an EXIDX section.
5673   // The static casting from Output_relaxed_input_section to
5674   // Arm_input_section is invalid in an EXIDX section.  We are okay
5675   // because we should not be calling this for an EXIDX section.
5676   gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5677
5678   // Currently we convert ordinary input sections into relaxed sections only
5679   // at this point but we may want to support creating relaxed input section
5680   // very early.  So we check here to see if owner is already a relaxed
5681   // section.
5682
5683   Arm_input_section<big_endian>* arm_input_section;
5684   if (owner->is_relaxed_input_section())
5685     {
5686       arm_input_section =
5687         Arm_input_section<big_endian>::as_arm_input_section(
5688           owner->relaxed_input_section());
5689     }
5690   else
5691     {
5692       gold_assert(owner->is_input_section());
5693       // Create a new relaxed input section.  We need to lock the original
5694       // file.
5695       Task_lock_obj<Object> tl(task, owner->relobj());
5696       arm_input_section =
5697         target->new_arm_input_section(owner->relobj(), owner->shndx());
5698       new_relaxed_sections->push_back(arm_input_section);
5699     }
5700
5701   // Create a stub table.
5702   Stub_table<big_endian>* stub_table =
5703     target->new_stub_table(arm_input_section);
5704
5705   arm_input_section->set_stub_table(stub_table);
5706
5707   Input_section_list::const_iterator p = begin;
5708   Input_section_list::const_iterator prev_p;
5709
5710   // Look for input sections or relaxed input sections in [begin ... end].
5711   do
5712     {
5713       if (p->is_input_section() || p->is_relaxed_input_section())
5714         {
5715           // The stub table information for input sections live
5716           // in their objects.
5717           Arm_relobj<big_endian>* arm_relobj =
5718             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5719           arm_relobj->set_stub_table(p->shndx(), stub_table);
5720         }
5721       prev_p = p++;
5722     }
5723   while (prev_p != end);
5724 }
5725
5726 // Group input sections for stub generation.  GROUP_SIZE is roughly the limit
5727 // of stub groups.  We grow a stub group by adding input section until the
5728 // size is just below GROUP_SIZE.  The last input section will be converted
5729 // into a stub table.  If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5730 // input section after the stub table, effectively double the group size.
5731 //
5732 // This is similar to the group_sections() function in elf32-arm.c but is
5733 // implemented differently.
5734
5735 template<bool big_endian>
5736 void
5737 Arm_output_section<big_endian>::group_sections(
5738     section_size_type group_size,
5739     bool stubs_always_after_branch,
5740     Target_arm<big_endian>* target,
5741     const Task* task)
5742 {
5743   // States for grouping.
5744   typedef enum
5745   {
5746     // No group is being built.
5747     NO_GROUP,
5748     // A group is being built but the stub table is not found yet.
5749     // We keep group a stub group until the size is just under GROUP_SIZE.
5750     // The last input section in the group will be used as the stub table.
5751     FINDING_STUB_SECTION,
5752     // A group is being built and we have already found a stub table.
5753     // We enter this state to grow a stub group by adding input section
5754     // after the stub table.  This effectively doubles the group size.
5755     HAS_STUB_SECTION
5756   } State;
5757
5758   // Any newly created relaxed sections are stored here.
5759   std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5760
5761   State state = NO_GROUP;
5762   section_size_type off = 0;
5763   section_size_type group_begin_offset = 0;
5764   section_size_type group_end_offset = 0;
5765   section_size_type stub_table_end_offset = 0;
5766   Input_section_list::const_iterator group_begin =
5767     this->input_sections().end();
5768   Input_section_list::const_iterator stub_table =
5769     this->input_sections().end();
5770   Input_section_list::const_iterator group_end = this->input_sections().end();
5771   for (Input_section_list::const_iterator p = this->input_sections().begin();
5772        p != this->input_sections().end();
5773        ++p)
5774     {
5775       section_size_type section_begin_offset =
5776         align_address(off, p->addralign());
5777       section_size_type section_end_offset =
5778         section_begin_offset + p->data_size();
5779
5780       // Check to see if we should group the previously seen sections.
5781       switch (state)
5782         {
5783         case NO_GROUP:
5784           break;
5785
5786         case FINDING_STUB_SECTION:
5787           // Adding this section makes the group larger than GROUP_SIZE.
5788           if (section_end_offset - group_begin_offset >= group_size)
5789             {
5790               if (stubs_always_after_branch)
5791                 {
5792                   gold_assert(group_end != this->input_sections().end());
5793                   this->create_stub_group(group_begin, group_end, group_end,
5794                                           target, &new_relaxed_sections,
5795                                           task);
5796                   state = NO_GROUP;
5797                 }
5798               else
5799                 {
5800                   // But wait, there's more!  Input sections up to
5801                   // stub_group_size bytes after the stub table can be
5802                   // handled by it too.
5803                   state = HAS_STUB_SECTION;
5804                   stub_table = group_end;
5805                   stub_table_end_offset = group_end_offset;
5806                 }
5807             }
5808             break;
5809
5810         case HAS_STUB_SECTION:
5811           // Adding this section makes the post stub-section group larger
5812           // than GROUP_SIZE.
5813           if (section_end_offset - stub_table_end_offset >= group_size)
5814            {
5815              gold_assert(group_end != this->input_sections().end());
5816              this->create_stub_group(group_begin, group_end, stub_table,
5817                                      target, &new_relaxed_sections, task);
5818              state = NO_GROUP;
5819            }
5820            break;
5821
5822           default:
5823             gold_unreachable();
5824         }
5825
5826       // If we see an input section and currently there is no group, start
5827       // a new one.  Skip any empty sections.  We look at the data size
5828       // instead of calling p->relobj()->section_size() to avoid locking.
5829       if ((p->is_input_section() || p->is_relaxed_input_section())
5830           && (p->data_size() != 0))
5831         {
5832           if (state == NO_GROUP)
5833             {
5834               state = FINDING_STUB_SECTION;
5835               group_begin = p;
5836               group_begin_offset = section_begin_offset;
5837             }
5838
5839           // Keep track of the last input section seen.
5840           group_end = p;
5841           group_end_offset = section_end_offset;
5842         }
5843
5844       off = section_end_offset;
5845     }
5846
5847   // Create a stub group for any ungrouped sections.
5848   if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5849     {
5850       gold_assert(group_end != this->input_sections().end());
5851       this->create_stub_group(group_begin, group_end,
5852                               (state == FINDING_STUB_SECTION
5853                                ? group_end
5854                                : stub_table),
5855                                target, &new_relaxed_sections, task);
5856     }
5857
5858   // Convert input section into relaxed input section in a batch.
5859   if (!new_relaxed_sections.empty())
5860     this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5861
5862   // Update the section offsets
5863   for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5864     {
5865       Arm_relobj<big_endian>* arm_relobj =
5866         Arm_relobj<big_endian>::as_arm_relobj(
5867           new_relaxed_sections[i]->relobj());
5868       unsigned int shndx = new_relaxed_sections[i]->shndx();
5869       // Tell Arm_relobj that this input section is converted.
5870       arm_relobj->convert_input_section_to_relaxed_section(shndx);
5871     }
5872 }
5873
5874 // Append non empty text sections in this to LIST in ascending
5875 // order of their position in this.
5876
5877 template<bool big_endian>
5878 void
5879 Arm_output_section<big_endian>::append_text_sections_to_list(
5880     Text_section_list* list)
5881 {
5882   gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5883
5884   for (Input_section_list::const_iterator p = this->input_sections().begin();
5885        p != this->input_sections().end();
5886        ++p)
5887     {
5888       // We only care about plain or relaxed input sections.  We also
5889       // ignore any merged sections.
5890       if (p->is_input_section() || p->is_relaxed_input_section())
5891         list->push_back(Text_section_list::value_type(p->relobj(),
5892                                                       p->shndx()));
5893     }
5894 }
5895
5896 template<bool big_endian>
5897 void
5898 Arm_output_section<big_endian>::fix_exidx_coverage(
5899     Layout* layout,
5900     const Text_section_list& sorted_text_sections,
5901     Symbol_table* symtab,
5902     bool merge_exidx_entries,
5903     const Task* task)
5904 {
5905   // We should only do this for the EXIDX output section.
5906   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5907
5908   // We don't want the relaxation loop to undo these changes, so we discard
5909   // the current saved states and take another one after the fix-up.
5910   this->discard_states();
5911
5912   // Remove all input sections.
5913   uint64_t address = this->address();
5914   typedef std::list<Output_section::Input_section> Input_section_list;
5915   Input_section_list input_sections;
5916   this->reset_address_and_file_offset();
5917   this->get_input_sections(address, std::string(""), &input_sections);
5918
5919   if (!this->input_sections().empty())
5920     gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5921
5922   // Go through all the known input sections and record them.
5923   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5924   typedef Unordered_map<Section_id, const Output_section::Input_section*,
5925                         Section_id_hash> Text_to_exidx_map;
5926   Text_to_exidx_map text_to_exidx_map;
5927   for (Input_section_list::const_iterator p = input_sections.begin();
5928        p != input_sections.end();
5929        ++p)
5930     {
5931       // This should never happen.  At this point, we should only see
5932       // plain EXIDX input sections.
5933       gold_assert(!p->is_relaxed_input_section());
5934       text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5935     }
5936
5937   Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5938
5939   // Go over the sorted text sections.
5940   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5941   Section_id_set processed_input_sections;
5942   for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5943        p != sorted_text_sections.end();
5944        ++p)
5945     {
5946       Relobj* relobj = p->first;
5947       unsigned int shndx = p->second;
5948
5949       Arm_relobj<big_endian>* arm_relobj =
5950          Arm_relobj<big_endian>::as_arm_relobj(relobj);
5951       const Arm_exidx_input_section* exidx_input_section =
5952          arm_relobj->exidx_input_section_by_link(shndx);
5953
5954       // If this text section has no EXIDX section or if the EXIDX section
5955       // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5956       // of the last seen EXIDX section.
5957       if (exidx_input_section == NULL || exidx_input_section->has_errors())
5958         {
5959           exidx_fixup.add_exidx_cantunwind_as_needed();
5960           continue;
5961         }
5962
5963       Relobj* exidx_relobj = exidx_input_section->relobj();
5964       unsigned int exidx_shndx = exidx_input_section->shndx();
5965       Section_id sid(exidx_relobj, exidx_shndx);
5966       Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5967       if (iter == text_to_exidx_map.end())
5968         {
5969           // This is odd.  We have not seen this EXIDX input section before.
5970           // We cannot do fix-up.  If we saw a SECTIONS clause in a script,
5971           // issue a warning instead.  We assume the user knows what he
5972           // or she is doing.  Otherwise, this is an error.
5973           if (layout->script_options()->saw_sections_clause())
5974             gold_warning(_("unwinding may not work because EXIDX input section"
5975                            " %u of %s is not in EXIDX output section"),
5976                          exidx_shndx, exidx_relobj->name().c_str());
5977           else
5978             gold_error(_("unwinding may not work because EXIDX input section"
5979                          " %u of %s is not in EXIDX output section"),
5980                        exidx_shndx, exidx_relobj->name().c_str());
5981
5982           exidx_fixup.add_exidx_cantunwind_as_needed();
5983           continue;
5984         }
5985
5986       // We need to access the contents of the EXIDX section, lock the
5987       // object here.
5988       Task_lock_obj<Object> tl(task, exidx_relobj);
5989       section_size_type exidx_size;
5990       const unsigned char* exidx_contents =
5991         exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5992
5993       // Fix up coverage and append input section to output data list.
5994       Arm_exidx_section_offset_map* section_offset_map = NULL;
5995       uint32_t deleted_bytes =
5996         exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5997                                                       exidx_contents,
5998                                                       exidx_size,
5999                                                       &section_offset_map);
6000
6001       if (deleted_bytes == exidx_input_section->size())
6002         {
6003           // The whole EXIDX section got merged.  Remove it from output.
6004           gold_assert(section_offset_map == NULL);
6005           exidx_relobj->set_output_section(exidx_shndx, NULL);
6006
6007           // All local symbols defined in this input section will be dropped.
6008           // We need to adjust output local symbol count.
6009           arm_relobj->set_output_local_symbol_count_needs_update();
6010         }
6011       else if (deleted_bytes > 0)
6012         {
6013           // Some entries are merged.  We need to convert this EXIDX input
6014           // section into a relaxed section.
6015           gold_assert(section_offset_map != NULL);
6016
6017           Arm_exidx_merged_section* merged_section =
6018             new Arm_exidx_merged_section(*exidx_input_section,
6019                                          *section_offset_map, deleted_bytes);
6020           merged_section->build_contents(exidx_contents, exidx_size);
6021
6022           const std::string secname = exidx_relobj->section_name(exidx_shndx);
6023           this->add_relaxed_input_section(layout, merged_section, secname);
6024           arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
6025
6026           // All local symbols defined in discarded portions of this input
6027           // section will be dropped.  We need to adjust output local symbol
6028           // count.
6029           arm_relobj->set_output_local_symbol_count_needs_update();
6030         }
6031       else
6032         {
6033           // Just add back the EXIDX input section.
6034           gold_assert(section_offset_map == NULL);
6035           const Output_section::Input_section* pis = iter->second;
6036           gold_assert(pis->is_input_section());
6037           this->add_script_input_section(*pis);
6038         }
6039
6040       processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
6041     }
6042
6043   // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
6044   exidx_fixup.add_exidx_cantunwind_as_needed();
6045
6046   // Remove any known EXIDX input sections that are not processed.
6047   for (Input_section_list::const_iterator p = input_sections.begin();
6048        p != input_sections.end();
6049        ++p)
6050     {
6051       if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
6052           == processed_input_sections.end())
6053         {
6054           // We discard a known EXIDX section because its linked
6055           // text section has been folded by ICF.  We also discard an
6056           // EXIDX section with error, the output does not matter in this
6057           // case.  We do this to avoid triggering asserts.
6058           Arm_relobj<big_endian>* arm_relobj =
6059             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6060           const Arm_exidx_input_section* exidx_input_section =
6061             arm_relobj->exidx_input_section_by_shndx(p->shndx());
6062           gold_assert(exidx_input_section != NULL);
6063           if (!exidx_input_section->has_errors())
6064             {
6065               unsigned int text_shndx = exidx_input_section->link();
6066               gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
6067             }
6068
6069           // Remove this from link.  We also need to recount the
6070           // local symbols.
6071           p->relobj()->set_output_section(p->shndx(), NULL);
6072           arm_relobj->set_output_local_symbol_count_needs_update();
6073         }
6074     }
6075
6076   // Link exidx output section to the first seen output section and
6077   // set correct entry size.
6078   this->set_link_section(exidx_fixup.first_output_text_section());
6079   this->set_entsize(8);
6080
6081   // Make changes permanent.
6082   this->save_states();
6083   this->set_section_offsets_need_adjustment();
6084 }
6085
6086 // Link EXIDX output sections to text output sections.
6087
6088 template<bool big_endian>
6089 void
6090 Arm_output_section<big_endian>::set_exidx_section_link()
6091 {
6092   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
6093   if (!this->input_sections().empty())
6094     {
6095       Input_section_list::const_iterator p = this->input_sections().begin();
6096       Arm_relobj<big_endian>* arm_relobj =
6097         Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6098       unsigned exidx_shndx = p->shndx();
6099       const Arm_exidx_input_section* exidx_input_section =
6100         arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6101       gold_assert(exidx_input_section != NULL);
6102       unsigned int text_shndx = exidx_input_section->link();
6103       Output_section* os = arm_relobj->output_section(text_shndx);
6104       this->set_link_section(os);
6105     }
6106 }
6107
6108 // Arm_relobj methods.
6109
6110 // Determine if an input section is scannable for stub processing.  SHDR is
6111 // the header of the section and SHNDX is the section index.  OS is the output
6112 // section for the input section and SYMTAB is the global symbol table used to
6113 // look up ICF information.
6114
6115 template<bool big_endian>
6116 bool
6117 Arm_relobj<big_endian>::section_is_scannable(
6118     const elfcpp::Shdr<32, big_endian>& shdr,
6119     unsigned int shndx,
6120     const Output_section* os,
6121     const Symbol_table* symtab)
6122 {
6123   // Skip any empty sections, unallocated sections or sections whose
6124   // type are not SHT_PROGBITS.
6125   if (shdr.get_sh_size() == 0
6126       || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6127       || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6128     return false;
6129
6130   // Skip any discarded or ICF'ed sections.
6131   if (os == NULL || symtab->is_section_folded(this, shndx))
6132     return false;
6133
6134   // If this requires special offset handling, check to see if it is
6135   // a relaxed section.  If this is not, then it is a merged section that
6136   // we cannot handle.
6137   if (this->is_output_section_offset_invalid(shndx))
6138     {
6139       const Output_relaxed_input_section* poris =
6140         os->find_relaxed_input_section(this, shndx);
6141       if (poris == NULL)
6142         return false;
6143     }
6144
6145   return true;
6146 }
6147
6148 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6149 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6150
6151 template<bool big_endian>
6152 bool
6153 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6154     const elfcpp::Shdr<32, big_endian>& shdr,
6155     const Relobj::Output_sections& out_sections,
6156     const Symbol_table* symtab,
6157     const unsigned char* pshdrs)
6158 {
6159   unsigned int sh_type = shdr.get_sh_type();
6160   if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6161     return false;
6162
6163   // Ignore empty section.
6164   off_t sh_size = shdr.get_sh_size();
6165   if (sh_size == 0)
6166     return false;
6167
6168   // Ignore reloc section with unexpected symbol table.  The
6169   // error will be reported in the final link.
6170   if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6171     return false;
6172
6173   unsigned int reloc_size;
6174   if (sh_type == elfcpp::SHT_REL)
6175     reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6176   else
6177     reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6178
6179   // Ignore reloc section with unexpected entsize or uneven size.
6180   // The error will be reported in the final link.
6181   if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6182     return false;
6183
6184   // Ignore reloc section with bad info.  This error will be
6185   // reported in the final link.
6186   unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6187   if (index >= this->shnum())
6188     return false;
6189
6190   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6191   const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6192   return this->section_is_scannable(text_shdr, index,
6193                                    out_sections[index], symtab);
6194 }
6195
6196 // Return the output address of either a plain input section or a relaxed
6197 // input section.  SHNDX is the section index.  We define and use this
6198 // instead of calling Output_section::output_address because that is slow
6199 // for large output.
6200
6201 template<bool big_endian>
6202 Arm_address
6203 Arm_relobj<big_endian>::simple_input_section_output_address(
6204     unsigned int shndx,
6205     Output_section* os)
6206 {
6207   if (this->is_output_section_offset_invalid(shndx))
6208     {
6209       const Output_relaxed_input_section* poris =
6210         os->find_relaxed_input_section(this, shndx);
6211       // We do not handle merged sections here.
6212       gold_assert(poris != NULL);
6213       return poris->address();
6214     }
6215   else
6216     return os->address() + this->get_output_section_offset(shndx);
6217 }
6218
6219 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6220 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6221
6222 template<bool big_endian>
6223 bool
6224 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6225     const elfcpp::Shdr<32, big_endian>& shdr,
6226     unsigned int shndx,
6227     Output_section* os,
6228     const Symbol_table* symtab)
6229 {
6230   if (!this->section_is_scannable(shdr, shndx, os, symtab))
6231     return false;
6232
6233   // If the section does not cross any 4K-boundaries, it does not need to
6234   // be scanned.
6235   Arm_address address = this->simple_input_section_output_address(shndx, os);
6236   if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6237     return false;
6238
6239   return true;
6240 }
6241
6242 // Scan a section for Cortex-A8 workaround.
6243
6244 template<bool big_endian>
6245 void
6246 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6247     const elfcpp::Shdr<32, big_endian>& shdr,
6248     unsigned int shndx,
6249     Output_section* os,
6250     Target_arm<big_endian>* arm_target)
6251 {
6252   // Look for the first mapping symbol in this section.  It should be
6253   // at (shndx, 0).
6254   Mapping_symbol_position section_start(shndx, 0);
6255   typename Mapping_symbols_info::const_iterator p =
6256     this->mapping_symbols_info_.lower_bound(section_start);
6257
6258   // There are no mapping symbols for this section.  Treat it as a data-only
6259   // section.
6260   if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6261     return;
6262
6263   Arm_address output_address =
6264     this->simple_input_section_output_address(shndx, os);
6265
6266   // Get the section contents.
6267   section_size_type input_view_size = 0;
6268   const unsigned char* input_view =
6269     this->section_contents(shndx, &input_view_size, false);
6270
6271   // We need to go through the mapping symbols to determine what to
6272   // scan.  There are two reasons.  First, we should look at THUMB code and
6273   // THUMB code only.  Second, we only want to look at the 4K-page boundary
6274   // to speed up the scanning.
6275
6276   while (p != this->mapping_symbols_info_.end()
6277         && p->first.first == shndx)
6278     {
6279       typename Mapping_symbols_info::const_iterator next =
6280         this->mapping_symbols_info_.upper_bound(p->first);
6281
6282       // Only scan part of a section with THUMB code.
6283       if (p->second == 't')
6284         {
6285           // Determine the end of this range.
6286           section_size_type span_start =
6287             convert_to_section_size_type(p->first.second);
6288           section_size_type span_end;
6289           if (next != this->mapping_symbols_info_.end()
6290               && next->first.first == shndx)
6291             span_end = convert_to_section_size_type(next->first.second);
6292           else
6293             span_end = convert_to_section_size_type(shdr.get_sh_size());
6294
6295           if (((span_start + output_address) & ~0xfffUL)
6296               != ((span_end + output_address - 1) & ~0xfffUL))
6297             {
6298               arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6299                                                           span_start, span_end,
6300                                                           input_view,
6301                                                           output_address);
6302             }
6303         }
6304
6305       p = next;
6306     }
6307 }
6308
6309 // Scan relocations for stub generation.
6310
6311 template<bool big_endian>
6312 void
6313 Arm_relobj<big_endian>::scan_sections_for_stubs(
6314     Target_arm<big_endian>* arm_target,
6315     const Symbol_table* symtab,
6316     const Layout* layout)
6317 {
6318   unsigned int shnum = this->shnum();
6319   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6320
6321   // Read the section headers.
6322   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6323                                                shnum * shdr_size,
6324                                                true, true);
6325
6326   // To speed up processing, we set up hash tables for fast lookup of
6327   // input offsets to output addresses.
6328   this->initialize_input_to_output_maps();
6329
6330   const Relobj::Output_sections& out_sections(this->output_sections());
6331
6332   Relocate_info<32, big_endian> relinfo;
6333   relinfo.symtab = symtab;
6334   relinfo.layout = layout;
6335   relinfo.object = this;
6336
6337   // Do relocation stubs scanning.
6338   const unsigned char* p = pshdrs + shdr_size;
6339   for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6340     {
6341       const elfcpp::Shdr<32, big_endian> shdr(p);
6342       if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6343                                                   pshdrs))
6344         {
6345           unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6346           Arm_address output_offset = this->get_output_section_offset(index);
6347           Arm_address output_address;
6348           if (output_offset != invalid_address)
6349             output_address = out_sections[index]->address() + output_offset;
6350           else
6351             {
6352               // Currently this only happens for a relaxed section.
6353               const Output_relaxed_input_section* poris =
6354               out_sections[index]->find_relaxed_input_section(this, index);
6355               gold_assert(poris != NULL);
6356               output_address = poris->address();
6357             }
6358
6359           // Get the relocations.
6360           const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6361                                                         shdr.get_sh_size(),
6362                                                         true, false);
6363
6364           // Get the section contents.  This does work for the case in which
6365           // we modify the contents of an input section.  We need to pass the
6366           // output view under such circumstances.
6367           section_size_type input_view_size = 0;
6368           const unsigned char* input_view =
6369             this->section_contents(index, &input_view_size, false);
6370
6371           relinfo.reloc_shndx = i;
6372           relinfo.data_shndx = index;
6373           unsigned int sh_type = shdr.get_sh_type();
6374           unsigned int reloc_size;
6375           if (sh_type == elfcpp::SHT_REL)
6376             reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6377           else
6378             reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6379
6380           Output_section* os = out_sections[index];
6381           arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6382                                              shdr.get_sh_size() / reloc_size,
6383                                              os,
6384                                              output_offset == invalid_address,
6385                                              input_view, output_address,
6386                                              input_view_size);
6387         }
6388     }
6389
6390   // Do Cortex-A8 erratum stubs scanning.  This has to be done for a section
6391   // after its relocation section, if there is one, is processed for
6392   // relocation stubs.  Merging this loop with the one above would have been
6393   // complicated since we would have had to make sure that relocation stub
6394   // scanning is done first.
6395   if (arm_target->fix_cortex_a8())
6396     {
6397       const unsigned char* p = pshdrs + shdr_size;
6398       for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6399         {
6400           const elfcpp::Shdr<32, big_endian> shdr(p);
6401           if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6402                                                           out_sections[i],
6403                                                           symtab))
6404             this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6405                                                      arm_target);
6406         }
6407     }
6408
6409   // After we've done the relocations, we release the hash tables,
6410   // since we no longer need them.
6411   this->free_input_to_output_maps();
6412 }
6413
6414 // Count the local symbols.  The ARM backend needs to know if a symbol
6415 // is a THUMB function or not.  For global symbols, it is easy because
6416 // the Symbol object keeps the ELF symbol type.  For local symbol it is
6417 // harder because we cannot access this information.   So we override the
6418 // do_count_local_symbol in parent and scan local symbols to mark
6419 // THUMB functions.  This is not the most efficient way but I do not want to
6420 // slow down other ports by calling a per symbol target hook inside
6421 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6422
6423 template<bool big_endian>
6424 void
6425 Arm_relobj<big_endian>::do_count_local_symbols(
6426     Stringpool_template<char>* pool,
6427     Stringpool_template<char>* dynpool)
6428 {
6429   // We need to fix-up the values of any local symbols whose type are
6430   // STT_ARM_TFUNC.
6431
6432   // Ask parent to count the local symbols.
6433   Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6434   const unsigned int loccount = this->local_symbol_count();
6435   if (loccount == 0)
6436     return;
6437
6438   // Initialize the thumb function bit-vector.
6439   std::vector<bool> empty_vector(loccount, false);
6440   this->local_symbol_is_thumb_function_.swap(empty_vector);
6441
6442   // Read the symbol table section header.
6443   const unsigned int symtab_shndx = this->symtab_shndx();
6444   elfcpp::Shdr<32, big_endian>
6445       symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6446   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6447
6448   // Read the local symbols.
6449   const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6450   gold_assert(loccount == symtabshdr.get_sh_info());
6451   off_t locsize = loccount * sym_size;
6452   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6453                                               locsize, true, true);
6454
6455   // For mapping symbol processing, we need to read the symbol names.
6456   unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6457   if (strtab_shndx >= this->shnum())
6458     {
6459       this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6460       return;
6461     }
6462
6463   elfcpp::Shdr<32, big_endian>
6464     strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6465   if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6466     {
6467       this->error(_("symbol table name section has wrong type: %u"),
6468                   static_cast<unsigned int>(strtabshdr.get_sh_type()));
6469       return;
6470     }
6471   const char* pnames =
6472     reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6473                                                  strtabshdr.get_sh_size(),
6474                                                  false, false));
6475
6476   // Loop over the local symbols and mark any local symbols pointing
6477   // to THUMB functions.
6478
6479   // Skip the first dummy symbol.
6480   psyms += sym_size;
6481   typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6482     this->local_values();
6483   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6484     {
6485       elfcpp::Sym<32, big_endian> sym(psyms);
6486       elfcpp::STT st_type = sym.get_st_type();
6487       Symbol_value<32>& lv((*plocal_values)[i]);
6488       Arm_address input_value = lv.input_value();
6489
6490       // Check to see if this is a mapping symbol.
6491       const char* sym_name = pnames + sym.get_st_name();
6492       if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6493         {
6494           bool is_ordinary;
6495           unsigned int input_shndx =
6496             this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6497           gold_assert(is_ordinary);
6498
6499           // Strip of LSB in case this is a THUMB symbol.
6500           Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6501           this->mapping_symbols_info_[msp] = sym_name[1];
6502         }
6503
6504       if (st_type == elfcpp::STT_ARM_TFUNC
6505           || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6506         {
6507           // This is a THUMB function.  Mark this and canonicalize the
6508           // symbol value by setting LSB.
6509           this->local_symbol_is_thumb_function_[i] = true;
6510           if ((input_value & 1) == 0)
6511             lv.set_input_value(input_value | 1);
6512         }
6513     }
6514 }
6515
6516 // Relocate sections.
6517 template<bool big_endian>
6518 void
6519 Arm_relobj<big_endian>::do_relocate_sections(
6520     const Symbol_table* symtab,
6521     const Layout* layout,
6522     const unsigned char* pshdrs,
6523     Output_file* of,
6524     typename Sized_relobj_file<32, big_endian>::Views* pviews)
6525 {
6526   // Call parent to relocate sections.
6527   Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6528                                                           pshdrs, of, pviews);
6529
6530   // We do not generate stubs if doing a relocatable link.
6531   if (parameters->options().relocatable())
6532     return;
6533
6534   // Relocate stub tables.
6535   unsigned int shnum = this->shnum();
6536
6537   Target_arm<big_endian>* arm_target =
6538     Target_arm<big_endian>::default_target();
6539
6540   Relocate_info<32, big_endian> relinfo;
6541   relinfo.symtab = symtab;
6542   relinfo.layout = layout;
6543   relinfo.object = this;
6544
6545   for (unsigned int i = 1; i < shnum; ++i)
6546     {
6547       Arm_input_section<big_endian>* arm_input_section =
6548         arm_target->find_arm_input_section(this, i);
6549
6550       if (arm_input_section != NULL
6551           && arm_input_section->is_stub_table_owner()
6552           && !arm_input_section->stub_table()->empty())
6553         {
6554           // We cannot discard a section if it owns a stub table.
6555           Output_section* os = this->output_section(i);
6556           gold_assert(os != NULL);
6557
6558           relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6559           relinfo.reloc_shdr = NULL;
6560           relinfo.data_shndx = i;
6561           relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6562
6563           gold_assert((*pviews)[i].view != NULL);
6564
6565           // We are passed the output section view.  Adjust it to cover the
6566           // stub table only.
6567           Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6568           gold_assert((stub_table->address() >= (*pviews)[i].address)
6569                       && ((stub_table->address() + stub_table->data_size())
6570                           <= (*pviews)[i].address + (*pviews)[i].view_size));
6571
6572           off_t offset = stub_table->address() - (*pviews)[i].address;
6573           unsigned char* view = (*pviews)[i].view + offset;
6574           Arm_address address = stub_table->address();
6575           section_size_type view_size = stub_table->data_size();
6576
6577           stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6578                                      view_size);
6579         }
6580
6581       // Apply Cortex A8 workaround if applicable.
6582       if (this->section_has_cortex_a8_workaround(i))
6583         {
6584           unsigned char* view = (*pviews)[i].view;
6585           Arm_address view_address = (*pviews)[i].address;
6586           section_size_type view_size = (*pviews)[i].view_size;
6587           Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6588
6589           // Adjust view to cover section.
6590           Output_section* os = this->output_section(i);
6591           gold_assert(os != NULL);
6592           Arm_address section_address =
6593             this->simple_input_section_output_address(i, os);
6594           uint64_t section_size = this->section_size(i);
6595
6596           gold_assert(section_address >= view_address
6597                       && ((section_address + section_size)
6598                           <= (view_address + view_size)));
6599
6600           unsigned char* section_view = view + (section_address - view_address);
6601
6602           // Apply the Cortex-A8 workaround to the output address range
6603           // corresponding to this input section.
6604           stub_table->apply_cortex_a8_workaround_to_address_range(
6605               arm_target,
6606               section_view,
6607               section_address,
6608               section_size);
6609         }
6610     }
6611 }
6612
6613 // Find the linked text section of an EXIDX section by looking at the first
6614 // relocation.  4.4.1 of the EHABI specifications says that an EXIDX section
6615 // must be linked to its associated code section via the sh_link field of
6616 // its section header.  However, some tools are broken and the link is not
6617 // always set.  LD just drops such an EXIDX section silently, causing the
6618 // associated code not unwindabled.   Here we try a little bit harder to
6619 // discover the linked code section.
6620 //
6621 // PSHDR points to the section header of a relocation section of an EXIDX
6622 // section.  If we can find a linked text section, return true and
6623 // store the text section index in the location PSHNDX.  Otherwise
6624 // return false.
6625
6626 template<bool big_endian>
6627 bool
6628 Arm_relobj<big_endian>::find_linked_text_section(
6629     const unsigned char* pshdr,
6630     const unsigned char* psyms,
6631     unsigned int* pshndx)
6632 {
6633   elfcpp::Shdr<32, big_endian> shdr(pshdr);
6634
6635   // If there is no relocation, we cannot find the linked text section.
6636   size_t reloc_size;
6637   if (shdr.get_sh_type() == elfcpp::SHT_REL)
6638       reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6639   else
6640       reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6641   size_t reloc_count = shdr.get_sh_size() / reloc_size;
6642
6643   // Get the relocations.
6644   const unsigned char* prelocs =
6645       this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6646
6647   // Find the REL31 relocation for the first word of the first EXIDX entry.
6648   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6649     {
6650       Arm_address r_offset;
6651       typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6652       if (shdr.get_sh_type() == elfcpp::SHT_REL)
6653         {
6654           typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6655           r_info = reloc.get_r_info();
6656           r_offset = reloc.get_r_offset();
6657         }
6658       else
6659         {
6660           typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6661           r_info = reloc.get_r_info();
6662           r_offset = reloc.get_r_offset();
6663         }
6664
6665       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6666       if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6667         continue;
6668
6669       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6670       if (r_sym == 0
6671           || r_sym >= this->local_symbol_count()
6672           || r_offset != 0)
6673         continue;
6674
6675       // This is the relocation for the first word of the first EXIDX entry.
6676       // We expect to see a local section symbol.
6677       const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6678       elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6679       if (sym.get_st_type() == elfcpp::STT_SECTION)
6680         {
6681           bool is_ordinary;
6682           *pshndx =
6683             this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6684           gold_assert(is_ordinary);
6685           return true;
6686         }
6687       else
6688         return false;
6689     }
6690
6691   return false;
6692 }
6693
6694 // Make an EXIDX input section object for an EXIDX section whose index is
6695 // SHNDX.  SHDR is the section header of the EXIDX section and TEXT_SHNDX
6696 // is the section index of the linked text section.
6697
6698 template<bool big_endian>
6699 void
6700 Arm_relobj<big_endian>::make_exidx_input_section(
6701     unsigned int shndx,
6702     const elfcpp::Shdr<32, big_endian>& shdr,
6703     unsigned int text_shndx,
6704     const elfcpp::Shdr<32, big_endian>& text_shdr)
6705 {
6706   // Create an Arm_exidx_input_section object for this EXIDX section.
6707   Arm_exidx_input_section* exidx_input_section =
6708     new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6709                                 shdr.get_sh_addralign(),
6710                                 text_shdr.get_sh_size());
6711
6712   gold_assert(this->exidx_section_map_[shndx] == NULL);
6713   this->exidx_section_map_[shndx] = exidx_input_section;
6714
6715   if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6716     {
6717       gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6718                  this->section_name(shndx).c_str(), shndx, text_shndx,
6719                  this->name().c_str());
6720       exidx_input_section->set_has_errors();
6721     }
6722   else if (this->exidx_section_map_[text_shndx] != NULL)
6723     {
6724       unsigned other_exidx_shndx =
6725         this->exidx_section_map_[text_shndx]->shndx();
6726       gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6727                    "%s(%u) in %s"),
6728                  this->section_name(shndx).c_str(), shndx,
6729                  this->section_name(other_exidx_shndx).c_str(),
6730                  other_exidx_shndx, this->section_name(text_shndx).c_str(),
6731                  text_shndx, this->name().c_str());
6732       exidx_input_section->set_has_errors();
6733     }
6734   else
6735      this->exidx_section_map_[text_shndx] = exidx_input_section;
6736
6737   // Check section flags of text section.
6738   if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6739     {
6740       gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6741                    " in %s"),
6742                  this->section_name(shndx).c_str(), shndx,
6743                  this->section_name(text_shndx).c_str(), text_shndx,
6744                  this->name().c_str());
6745       exidx_input_section->set_has_errors();
6746     }
6747   else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6748     // I would like to make this an error but currently ld just ignores
6749     // this.
6750     gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6751                    "%s(%u) in %s"),
6752                  this->section_name(shndx).c_str(), shndx,
6753                  this->section_name(text_shndx).c_str(), text_shndx,
6754                  this->name().c_str());
6755 }
6756
6757 // Read the symbol information.
6758
6759 template<bool big_endian>
6760 void
6761 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6762 {
6763   // Call parent class to read symbol information.
6764   this->base_read_symbols(sd);
6765
6766   // If this input file is a binary file, it has no processor
6767   // specific flags and attributes section.
6768   Input_file::Format format = this->input_file()->format();
6769   if (format != Input_file::FORMAT_ELF)
6770     {
6771       gold_assert(format == Input_file::FORMAT_BINARY);
6772       this->merge_flags_and_attributes_ = false;
6773       return;
6774     }
6775
6776   // Read processor-specific flags in ELF file header.
6777   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6778                                               elfcpp::Elf_sizes<32>::ehdr_size,
6779                                               true, false);
6780   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6781   this->processor_specific_flags_ = ehdr.get_e_flags();
6782
6783   // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6784   // sections.
6785   std::vector<unsigned int> deferred_exidx_sections;
6786   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6787   const unsigned char* pshdrs = sd->section_headers->data();
6788   const unsigned char* ps = pshdrs + shdr_size;
6789   bool must_merge_flags_and_attributes = false;
6790   for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6791     {
6792       elfcpp::Shdr<32, big_endian> shdr(ps);
6793
6794       // Sometimes an object has no contents except the section name string
6795       // table and an empty symbol table with the undefined symbol.  We
6796       // don't want to merge processor-specific flags from such an object.
6797       if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6798         {
6799           // Symbol table is not empty.
6800           const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6801              elfcpp::Elf_sizes<32>::sym_size;
6802           if (shdr.get_sh_size() > sym_size)
6803             must_merge_flags_and_attributes = true;
6804         }
6805       else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6806         // If this is neither an empty symbol table nor a string table,
6807         // be conservative.
6808         must_merge_flags_and_attributes = true;
6809
6810       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6811         {
6812           gold_assert(this->attributes_section_data_ == NULL);
6813           section_offset_type section_offset = shdr.get_sh_offset();
6814           section_size_type section_size =
6815             convert_to_section_size_type(shdr.get_sh_size());
6816           const unsigned char* view =
6817              this->get_view(section_offset, section_size, true, false);
6818           this->attributes_section_data_ =
6819             new Attributes_section_data(view, section_size);
6820         }
6821       else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6822         {
6823           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6824           if (text_shndx == elfcpp::SHN_UNDEF)
6825             deferred_exidx_sections.push_back(i);
6826           else
6827             {
6828               elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6829                                                      + text_shndx * shdr_size);
6830               this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6831             }
6832           // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6833           if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6834             gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6835                          this->section_name(i).c_str(), this->name().c_str());
6836         }
6837     }
6838
6839   // This is rare.
6840   if (!must_merge_flags_and_attributes)
6841     {
6842       gold_assert(deferred_exidx_sections.empty());
6843       this->merge_flags_and_attributes_ = false;
6844       return;
6845     }
6846
6847   // Some tools are broken and they do not set the link of EXIDX sections.
6848   // We look at the first relocation to figure out the linked sections.
6849   if (!deferred_exidx_sections.empty())
6850     {
6851       // We need to go over the section headers again to find the mapping
6852       // from sections being relocated to their relocation sections.  This is
6853       // a bit inefficient as we could do that in the loop above.  However,
6854       // we do not expect any deferred EXIDX sections normally.  So we do not
6855       // want to slow down the most common path.
6856       typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6857       Reloc_map reloc_map;
6858       ps = pshdrs + shdr_size;
6859       for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6860         {
6861           elfcpp::Shdr<32, big_endian> shdr(ps);
6862           elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6863           if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6864             {
6865               unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6866               if (info_shndx >= this->shnum())
6867                 gold_error(_("relocation section %u has invalid info %u"),
6868                            i, info_shndx);
6869               Reloc_map::value_type value(info_shndx, i);
6870               std::pair<Reloc_map::iterator, bool> result =
6871                 reloc_map.insert(value);
6872               if (!result.second)
6873                 gold_error(_("section %u has multiple relocation sections "
6874                              "%u and %u"),
6875                            info_shndx, i, reloc_map[info_shndx]);
6876             }
6877         }
6878
6879       // Read the symbol table section header.
6880       const unsigned int symtab_shndx = this->symtab_shndx();
6881       elfcpp::Shdr<32, big_endian>
6882           symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6883       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6884
6885       // Read the local symbols.
6886       const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6887       const unsigned int loccount = this->local_symbol_count();
6888       gold_assert(loccount == symtabshdr.get_sh_info());
6889       off_t locsize = loccount * sym_size;
6890       const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6891                                                   locsize, true, true);
6892
6893       // Process the deferred EXIDX sections.
6894       for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6895         {
6896           unsigned int shndx = deferred_exidx_sections[i];
6897           elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6898           unsigned int text_shndx = elfcpp::SHN_UNDEF;
6899           Reloc_map::const_iterator it = reloc_map.find(shndx);
6900           if (it != reloc_map.end())
6901             find_linked_text_section(pshdrs + it->second * shdr_size,
6902                                      psyms, &text_shndx);
6903           elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6904                                                  + text_shndx * shdr_size);
6905           this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6906         }
6907     }
6908 }
6909
6910 // Process relocations for garbage collection.  The ARM target uses .ARM.exidx
6911 // sections for unwinding.  These sections are referenced implicitly by
6912 // text sections linked in the section headers.  If we ignore these implicit
6913 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6914 // will be garbage-collected incorrectly.  Hence we override the same function
6915 // in the base class to handle these implicit references.
6916
6917 template<bool big_endian>
6918 void
6919 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6920                                              Layout* layout,
6921                                              Read_relocs_data* rd)
6922 {
6923   // First, call base class method to process relocations in this object.
6924   Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6925
6926   // If --gc-sections is not specified, there is nothing more to do.
6927   // This happens when --icf is used but --gc-sections is not.
6928   if (!parameters->options().gc_sections())
6929     return;
6930
6931   unsigned int shnum = this->shnum();
6932   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6933   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6934                                                shnum * shdr_size,
6935                                                true, true);
6936
6937   // Scan section headers for sections of type SHT_ARM_EXIDX.  Add references
6938   // to these from the linked text sections.
6939   const unsigned char* ps = pshdrs + shdr_size;
6940   for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6941     {
6942       elfcpp::Shdr<32, big_endian> shdr(ps);
6943       if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6944         {
6945           // Found an .ARM.exidx section, add it to the set of reachable
6946           // sections from its linked text section.
6947           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6948           symtab->gc()->add_reference(this, text_shndx, this, i);
6949         }
6950     }
6951 }
6952
6953 // Update output local symbol count.  Owing to EXIDX entry merging, some local
6954 // symbols  will be removed in output.  Adjust output local symbol count
6955 // accordingly.  We can only changed the static output local symbol count.  It
6956 // is too late to change the dynamic symbols.
6957
6958 template<bool big_endian>
6959 void
6960 Arm_relobj<big_endian>::update_output_local_symbol_count()
6961 {
6962   // Caller should check that this needs updating.  We want caller checking
6963   // because output_local_symbol_count_needs_update() is most likely inlined.
6964   gold_assert(this->output_local_symbol_count_needs_update_);
6965
6966   gold_assert(this->symtab_shndx() != -1U);
6967   if (this->symtab_shndx() == 0)
6968     {
6969       // This object has no symbols.  Weird but legal.
6970       return;
6971     }
6972
6973   // Read the symbol table section header.
6974   const unsigned int symtab_shndx = this->symtab_shndx();
6975   elfcpp::Shdr<32, big_endian>
6976     symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6977   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6978
6979   // Read the local symbols.
6980   const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6981   const unsigned int loccount = this->local_symbol_count();
6982   gold_assert(loccount == symtabshdr.get_sh_info());
6983   off_t locsize = loccount * sym_size;
6984   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6985                                               locsize, true, true);
6986
6987   // Loop over the local symbols.
6988
6989   typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6990      Output_sections;
6991   const Output_sections& out_sections(this->output_sections());
6992   unsigned int shnum = this->shnum();
6993   unsigned int count = 0;
6994   // Skip the first, dummy, symbol.
6995   psyms += sym_size;
6996   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6997     {
6998       elfcpp::Sym<32, big_endian> sym(psyms);
6999
7000       Symbol_value<32>& lv((*this->local_values())[i]);
7001
7002       // This local symbol was already discarded by do_count_local_symbols.
7003       if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
7004         continue;
7005
7006       bool is_ordinary;
7007       unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
7008                                                   &is_ordinary);
7009
7010       if (shndx < shnum)
7011         {
7012           Output_section* os = out_sections[shndx];
7013
7014           // This local symbol no longer has an output section.  Discard it.
7015           if (os == NULL)
7016             {
7017               lv.set_no_output_symtab_entry();
7018               continue;
7019             }
7020
7021           // Currently we only discard parts of EXIDX input sections.
7022           // We explicitly check for a merged EXIDX input section to avoid
7023           // calling Output_section_data::output_offset unless necessary.
7024           if ((this->get_output_section_offset(shndx) == invalid_address)
7025               && (this->exidx_input_section_by_shndx(shndx) != NULL))
7026             {
7027               section_offset_type output_offset =
7028                 os->output_offset(this, shndx, lv.input_value());
7029               if (output_offset == -1)
7030                 {
7031                   // This symbol is defined in a part of an EXIDX input section
7032                   // that is discarded due to entry merging.
7033                   lv.set_no_output_symtab_entry();
7034                   continue;
7035                 }
7036             }
7037         }
7038
7039       ++count;
7040     }
7041
7042   this->set_output_local_symbol_count(count);
7043   this->output_local_symbol_count_needs_update_ = false;
7044 }
7045
7046 // Arm_dynobj methods.
7047
7048 // Read the symbol information.
7049
7050 template<bool big_endian>
7051 void
7052 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
7053 {
7054   // Call parent class to read symbol information.
7055   this->base_read_symbols(sd);
7056
7057   // Read processor-specific flags in ELF file header.
7058   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
7059                                               elfcpp::Elf_sizes<32>::ehdr_size,
7060                                               true, false);
7061   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
7062   this->processor_specific_flags_ = ehdr.get_e_flags();
7063
7064   // Read the attributes section if there is one.
7065   // We read from the end because gas seems to put it near the end of
7066   // the section headers.
7067   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
7068   const unsigned char* ps =
7069     sd->section_headers->data() + shdr_size * (this->shnum() - 1);
7070   for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
7071     {
7072       elfcpp::Shdr<32, big_endian> shdr(ps);
7073       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
7074         {
7075           section_offset_type section_offset = shdr.get_sh_offset();
7076           section_size_type section_size =
7077             convert_to_section_size_type(shdr.get_sh_size());
7078           const unsigned char* view =
7079             this->get_view(section_offset, section_size, true, false);
7080           this->attributes_section_data_ =
7081             new Attributes_section_data(view, section_size);
7082           break;
7083         }
7084     }
7085 }
7086
7087 // Stub_addend_reader methods.
7088
7089 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7090
7091 template<bool big_endian>
7092 elfcpp::Elf_types<32>::Elf_Swxword
7093 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7094     unsigned int r_type,
7095     const unsigned char* view,
7096     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7097 {
7098   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
7099
7100   switch (r_type)
7101     {
7102     case elfcpp::R_ARM_CALL:
7103     case elfcpp::R_ARM_JUMP24:
7104     case elfcpp::R_ARM_PLT32:
7105       {
7106         typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7107         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7108         Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7109         return Bits<26>::sign_extend32(val << 2);
7110       }
7111
7112     case elfcpp::R_ARM_THM_CALL:
7113     case elfcpp::R_ARM_THM_JUMP24:
7114     case elfcpp::R_ARM_THM_XPC22:
7115       {
7116         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7117         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7118         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7119         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7120         return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7121       }
7122
7123     case elfcpp::R_ARM_THM_JUMP19:
7124       {
7125         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7126         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7127         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7128         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7129         return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7130       }
7131
7132     default:
7133       gold_unreachable();
7134     }
7135 }
7136
7137 // Arm_output_data_got methods.
7138
7139 // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
7140 // The first one is initialized to be 1, which is the module index for
7141 // the main executable and the second one 0.  A reloc of the type
7142 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7143 // be applied by gold.  GSYM is a global symbol.
7144 //
7145 template<bool big_endian>
7146 void
7147 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7148     unsigned int got_type,
7149     Symbol* gsym)
7150 {
7151   if (gsym->has_got_offset(got_type))
7152     return;
7153
7154   // We are doing a static link.  Just mark it as belong to module 1,
7155   // the executable.
7156   unsigned int got_offset = this->add_constant(1);
7157   gsym->set_got_offset(got_type, got_offset);
7158   got_offset = this->add_constant(0);
7159   this->static_relocs_.push_back(Static_reloc(got_offset,
7160                                               elfcpp::R_ARM_TLS_DTPOFF32,
7161                                               gsym));
7162 }
7163
7164 // Same as the above but for a local symbol.
7165
7166 template<bool big_endian>
7167 void
7168 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7169   unsigned int got_type,
7170   Sized_relobj_file<32, big_endian>* object,
7171   unsigned int index)
7172 {
7173   if (object->local_has_got_offset(index, got_type))
7174     return;
7175
7176   // We are doing a static link.  Just mark it as belong to module 1,
7177   // the executable.
7178   unsigned int got_offset = this->add_constant(1);
7179   object->set_local_got_offset(index, got_type, got_offset);
7180   got_offset = this->add_constant(0);
7181   this->static_relocs_.push_back(Static_reloc(got_offset,
7182                                               elfcpp::R_ARM_TLS_DTPOFF32,
7183                                               object, index));
7184 }
7185
7186 template<bool big_endian>
7187 void
7188 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7189 {
7190   // Call parent to write out GOT.
7191   Output_data_got<32, big_endian>::do_write(of);
7192
7193   // We are done if there is no fix up.
7194   if (this->static_relocs_.empty())
7195     return;
7196
7197   gold_assert(parameters->doing_static_link());
7198
7199   const off_t offset = this->offset();
7200   const section_size_type oview_size =
7201     convert_to_section_size_type(this->data_size());
7202   unsigned char* const oview = of->get_output_view(offset, oview_size);
7203
7204   Output_segment* tls_segment = this->layout_->tls_segment();
7205   gold_assert(tls_segment != NULL);
7206
7207   // The thread pointer $tp points to the TCB, which is followed by the
7208   // TLS.  So we need to adjust $tp relative addressing by this amount.
7209   Arm_address aligned_tcb_size =
7210     align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7211
7212   for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7213     {
7214       Static_reloc& reloc(this->static_relocs_[i]);
7215
7216       Arm_address value;
7217       if (!reloc.symbol_is_global())
7218         {
7219           Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7220           const Symbol_value<32>* psymval =
7221             reloc.relobj()->local_symbol(reloc.index());
7222
7223           // We are doing static linking.  Issue an error and skip this
7224           // relocation if the symbol is undefined or in a discarded_section.
7225           bool is_ordinary;
7226           unsigned int shndx = psymval->input_shndx(&is_ordinary);
7227           if ((shndx == elfcpp::SHN_UNDEF)
7228               || (is_ordinary
7229                   && shndx != elfcpp::SHN_UNDEF
7230                   && !object->is_section_included(shndx)
7231                   && !this->symbol_table_->is_section_folded(object, shndx)))
7232             {
7233               gold_error(_("undefined or discarded local symbol %u from "
7234                            " object %s in GOT"),
7235                          reloc.index(), reloc.relobj()->name().c_str());
7236               continue;
7237             }
7238
7239           value = psymval->value(object, 0);
7240         }
7241       else
7242         {
7243           const Symbol* gsym = reloc.symbol();
7244           gold_assert(gsym != NULL);
7245           if (gsym->is_forwarder())
7246             gsym = this->symbol_table_->resolve_forwards(gsym);
7247
7248           // We are doing static linking.  Issue an error and skip this
7249           // relocation if the symbol is undefined or in a discarded_section
7250           // unless it is a weakly_undefined symbol.
7251           if ((gsym->is_defined_in_discarded_section()
7252                || gsym->is_undefined())
7253               && !gsym->is_weak_undefined())
7254             {
7255               gold_error(_("undefined or discarded symbol %s in GOT"),
7256                          gsym->name());
7257               continue;
7258             }
7259
7260           if (!gsym->is_weak_undefined())
7261             {
7262               const Sized_symbol<32>* sym =
7263                 static_cast<const Sized_symbol<32>*>(gsym);
7264               value = sym->value();
7265             }
7266           else
7267               value = 0;
7268         }
7269
7270       unsigned got_offset = reloc.got_offset();
7271       gold_assert(got_offset < oview_size);
7272
7273       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7274       Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7275       Valtype x;
7276       switch (reloc.r_type())
7277         {
7278         case elfcpp::R_ARM_TLS_DTPOFF32:
7279           x = value;
7280           break;
7281         case elfcpp::R_ARM_TLS_TPOFF32:
7282           x = value + aligned_tcb_size;
7283           break;
7284         default:
7285           gold_unreachable();
7286         }
7287       elfcpp::Swap<32, big_endian>::writeval(wv, x);
7288     }
7289
7290   of->write_output_view(offset, oview_size, oview);
7291 }
7292
7293 // A class to handle the PLT data.
7294 // This is an abstract base class that handles most of the linker details
7295 // but does not know the actual contents of PLT entries.  The derived
7296 // classes below fill in those details.
7297
7298 template<bool big_endian>
7299 class Output_data_plt_arm : public Output_section_data
7300 {
7301  public:
7302   // Unlike aarch64, which records symbol value in "addend" field of relocations
7303   // and could be done at the same time an IRelative reloc is created for the
7304   // symbol, arm puts the symbol value into "GOT" table, which, however, is
7305   // issued later in Output_data_plt_arm::do_write(). So we have a struct here
7306   // to keep necessary symbol information for later use in do_write. We usually
7307   // have only a very limited number of ifuncs, so the extra data required here
7308   // is also limited.
7309
7310   struct IRelative_data
7311   {
7312     IRelative_data(Sized_symbol<32>* sized_symbol)
7313       : symbol_is_global_(true)
7314     {
7315       u_.global = sized_symbol;
7316     }
7317
7318     IRelative_data(Sized_relobj_file<32, big_endian>* relobj,
7319                    unsigned int index)
7320       : symbol_is_global_(false)
7321     {
7322       u_.local.relobj = relobj;
7323       u_.local.index = index;
7324     }
7325
7326     union
7327     {
7328       Sized_symbol<32>* global;
7329
7330       struct
7331       {
7332         Sized_relobj_file<32, big_endian>* relobj;
7333         unsigned int index;
7334       } local;
7335     } u_;
7336
7337     bool symbol_is_global_;
7338   };
7339
7340   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7341     Reloc_section;
7342
7343   Output_data_plt_arm(Layout* layout, uint64_t addralign,
7344                       Arm_output_data_got<big_endian>* got,
7345                       Output_data_space* got_plt,
7346                       Output_data_space* got_irelative);
7347
7348   // Add an entry to the PLT.
7349   void
7350   add_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym);
7351
7352   // Add the relocation for a plt entry.
7353   void
7354   add_relocation(Symbol_table* symtab, Layout* layout,
7355                  Symbol* gsym, unsigned int got_offset);
7356
7357   // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
7358   unsigned int
7359   add_local_ifunc_entry(Symbol_table* symtab, Layout*,
7360                         Sized_relobj_file<32, big_endian>* relobj,
7361                         unsigned int local_sym_index);
7362
7363   // Return the .rel.plt section data.
7364   const Reloc_section*
7365   rel_plt() const
7366   { return this->rel_; }
7367
7368   // Return the PLT relocation container for IRELATIVE.
7369   Reloc_section*
7370   rel_irelative(Symbol_table*, Layout*);
7371
7372   // Return the number of PLT entries.
7373   unsigned int
7374   entry_count() const
7375   { return this->count_ + this->irelative_count_; }
7376
7377   // Return the offset of the first non-reserved PLT entry.
7378   unsigned int
7379   first_plt_entry_offset() const
7380   { return this->do_first_plt_entry_offset(); }
7381
7382   // Return the size of a PLT entry.
7383   unsigned int
7384   get_plt_entry_size() const
7385   { return this->do_get_plt_entry_size(); }
7386
7387   // Return the PLT address for globals.
7388   uint32_t
7389   address_for_global(const Symbol*) const;
7390
7391   // Return the PLT address for locals.
7392   uint32_t
7393   address_for_local(const Relobj*, unsigned int symndx) const;
7394
7395  protected:
7396   // Fill in the first PLT entry.
7397   void
7398   fill_first_plt_entry(unsigned char* pov,
7399                        Arm_address got_address,
7400                        Arm_address plt_address)
7401   { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
7402
7403   void
7404   fill_plt_entry(unsigned char* pov,
7405                  Arm_address got_address,
7406                  Arm_address plt_address,
7407                  unsigned int got_offset,
7408                  unsigned int plt_offset)
7409   { do_fill_plt_entry(pov, got_address, plt_address, got_offset, plt_offset); }
7410
7411   virtual unsigned int
7412   do_first_plt_entry_offset() const = 0;
7413
7414   virtual unsigned int
7415   do_get_plt_entry_size() const = 0;
7416
7417   virtual void
7418   do_fill_first_plt_entry(unsigned char* pov,
7419                           Arm_address got_address,
7420                           Arm_address plt_address) = 0;
7421
7422   virtual void
7423   do_fill_plt_entry(unsigned char* pov,
7424                     Arm_address got_address,
7425                     Arm_address plt_address,
7426                     unsigned int got_offset,
7427                     unsigned int plt_offset) = 0;
7428
7429   void
7430   do_adjust_output_section(Output_section* os);
7431
7432   // Write to a map file.
7433   void
7434   do_print_to_mapfile(Mapfile* mapfile) const
7435   { mapfile->print_output_data(this, _("** PLT")); }
7436
7437  private:
7438   // Set the final size.
7439   void
7440   set_final_data_size()
7441   {
7442     this->set_data_size(this->first_plt_entry_offset()
7443                         + ((this->count_ + this->irelative_count_)
7444                            * this->get_plt_entry_size()));
7445   }
7446
7447   // Write out the PLT data.
7448   void
7449   do_write(Output_file*);
7450
7451   // Record irelative symbol data.
7452   void insert_irelative_data(const IRelative_data& idata)
7453   { irelative_data_vec_.push_back(idata); }
7454
7455   // The reloc section.
7456   Reloc_section* rel_;
7457   // The IRELATIVE relocs, if necessary.  These must follow the
7458   // regular PLT relocations.
7459   Reloc_section* irelative_rel_;
7460   // The .got section.
7461   Arm_output_data_got<big_endian>* got_;
7462   // The .got.plt section.
7463   Output_data_space* got_plt_;
7464   // The part of the .got.plt section used for IRELATIVE relocs.
7465   Output_data_space* got_irelative_;
7466   // The number of PLT entries.
7467   unsigned int count_;
7468   // Number of PLT entries with R_ARM_IRELATIVE relocs.  These
7469   // follow the regular PLT entries.
7470   unsigned int irelative_count_;
7471   // Vector for irelative data.
7472   typedef std::vector<IRelative_data> IRelative_data_vec;
7473   IRelative_data_vec irelative_data_vec_;
7474 };
7475
7476 // Create the PLT section.  The ordinary .got section is an argument,
7477 // since we need to refer to the start.  We also create our own .got
7478 // section just for PLT entries.
7479
7480 template<bool big_endian>
7481 Output_data_plt_arm<big_endian>::Output_data_plt_arm(
7482     Layout* layout, uint64_t addralign,
7483     Arm_output_data_got<big_endian>* got,
7484     Output_data_space* got_plt,
7485     Output_data_space* got_irelative)
7486   : Output_section_data(addralign), irelative_rel_(NULL),
7487     got_(got), got_plt_(got_plt), got_irelative_(got_irelative),
7488     count_(0), irelative_count_(0)
7489 {
7490   this->rel_ = new Reloc_section(false);
7491   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7492                                   elfcpp::SHF_ALLOC, this->rel_,
7493                                   ORDER_DYNAMIC_PLT_RELOCS, false);
7494 }
7495
7496 template<bool big_endian>
7497 void
7498 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7499 {
7500   os->set_entsize(0);
7501 }
7502
7503 // Add an entry to the PLT.
7504
7505 template<bool big_endian>
7506 void
7507 Output_data_plt_arm<big_endian>::add_entry(Symbol_table* symtab,
7508                                            Layout* layout,
7509                                            Symbol* gsym)
7510 {
7511   gold_assert(!gsym->has_plt_offset());
7512
7513   unsigned int* entry_count;
7514   Output_section_data_build* got;
7515
7516   // We have 2 different types of plt entry here, normal and ifunc.
7517
7518   // For normal plt, the offset begins with first_plt_entry_offset(20), and the
7519   // 1st entry offset would be 20, the second 32, third 44 ... etc.
7520
7521   // For ifunc plt, the offset begins with 0. So the first offset would 0,
7522   // second 12, third 24 ... etc.
7523
7524   // IFunc plt entries *always* come after *normal* plt entries.
7525
7526   // Notice, when computing the plt address of a certain symbol, "plt_address +
7527   // plt_offset" is no longer correct. Use target->plt_address_for_global() or
7528   // target->plt_address_for_local() instead.
7529
7530   int begin_offset = 0;
7531   if (gsym->type() == elfcpp::STT_GNU_IFUNC
7532       && gsym->can_use_relative_reloc(false))
7533     {
7534       entry_count = &this->irelative_count_;
7535       got = this->got_irelative_;
7536       // For irelative plt entries, offset is relative to the end of normal plt
7537       // entries, so it starts from 0.
7538       begin_offset = 0;
7539       // Record symbol information.
7540       this->insert_irelative_data(
7541           IRelative_data(symtab->get_sized_symbol<32>(gsym)));
7542     }
7543   else
7544     {
7545       entry_count = &this->count_;
7546       got = this->got_plt_;
7547       // Note that for normal plt entries, when setting the PLT offset we skip
7548       // the initial reserved PLT entry.
7549       begin_offset = this->first_plt_entry_offset();
7550     }
7551
7552   gsym->set_plt_offset(begin_offset
7553                        + (*entry_count) * this->get_plt_entry_size());
7554
7555   ++(*entry_count);
7556
7557   section_offset_type got_offset = got->current_data_size();
7558
7559   // Every PLT entry needs a GOT entry which points back to the PLT
7560   // entry (this will be changed by the dynamic linker, normally
7561   // lazily when the function is called).
7562   got->set_current_data_size(got_offset + 4);
7563
7564   // Every PLT entry needs a reloc.
7565   this->add_relocation(symtab, layout, gsym, got_offset);
7566
7567   // Note that we don't need to save the symbol.  The contents of the
7568   // PLT are independent of which symbols are used.  The symbols only
7569   // appear in the relocations.
7570 }
7571
7572 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.  Return
7573 // the PLT offset.
7574
7575 template<bool big_endian>
7576 unsigned int
7577 Output_data_plt_arm<big_endian>::add_local_ifunc_entry(
7578     Symbol_table* symtab,
7579     Layout* layout,
7580     Sized_relobj_file<32, big_endian>* relobj,
7581     unsigned int local_sym_index)
7582 {
7583   this->insert_irelative_data(IRelative_data(relobj, local_sym_index));
7584
7585   // Notice, when computingthe plt entry address, "plt_address + plt_offset" is
7586   // no longer correct. Use target->plt_address_for_local() instead.
7587   unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
7588   ++this->irelative_count_;
7589
7590   section_offset_type got_offset = this->got_irelative_->current_data_size();
7591
7592   // Every PLT entry needs a GOT entry which points back to the PLT
7593   // entry.
7594   this->got_irelative_->set_current_data_size(got_offset + 4);
7595
7596
7597   // Every PLT entry needs a reloc.
7598   Reloc_section* rel = this->rel_irelative(symtab, layout);
7599   rel->add_symbolless_local_addend(relobj, local_sym_index,
7600                                    elfcpp::R_ARM_IRELATIVE,
7601                                    this->got_irelative_, got_offset);
7602   return plt_offset;
7603 }
7604
7605
7606 // Add the relocation for a PLT entry.
7607
7608 template<bool big_endian>
7609 void
7610 Output_data_plt_arm<big_endian>::add_relocation(
7611     Symbol_table* symtab, Layout* layout, Symbol* gsym, unsigned int got_offset)
7612 {
7613   if (gsym->type() == elfcpp::STT_GNU_IFUNC
7614       && gsym->can_use_relative_reloc(false))
7615     {
7616       Reloc_section* rel = this->rel_irelative(symtab, layout);
7617       rel->add_symbolless_global_addend(gsym, elfcpp::R_ARM_IRELATIVE,
7618                                         this->got_irelative_, got_offset);
7619     }
7620   else
7621     {
7622       gsym->set_needs_dynsym_entry();
7623       this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7624                              got_offset);
7625     }
7626 }
7627
7628
7629 // Create the irelative relocation data.
7630
7631 template<bool big_endian>
7632 typename Output_data_plt_arm<big_endian>::Reloc_section*
7633 Output_data_plt_arm<big_endian>::rel_irelative(Symbol_table* symtab,
7634                                                 Layout* layout)
7635 {
7636   if (this->irelative_rel_ == NULL)
7637     {
7638       // Since irelative relocations goes into 'rel.dyn', we delegate the
7639       // creation of irelative_rel_ to where rel_dyn section gets created.
7640       Target_arm<big_endian>* arm_target =
7641           Target_arm<big_endian>::default_target();
7642       this->irelative_rel_ = arm_target->rel_irelative_section(layout);
7643
7644       // Make sure we have a place for the TLSDESC relocations, in
7645       // case we see any later on.
7646       // this->rel_tlsdesc(layout);
7647       if (parameters->doing_static_link())
7648         {
7649           // A statically linked executable will only have a .rel.plt section to
7650           // hold R_ARM_IRELATIVE relocs for STT_GNU_IFUNC symbols.  The library
7651           // will use these symbols to locate the IRELATIVE relocs at program
7652           // startup time.
7653           symtab->define_in_output_data("__rel_iplt_start", NULL,
7654                                         Symbol_table::PREDEFINED,
7655                                         this->irelative_rel_, 0, 0,
7656                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
7657                                         elfcpp::STV_HIDDEN, 0, false, true);
7658           symtab->define_in_output_data("__rel_iplt_end", NULL,
7659                                         Symbol_table::PREDEFINED,
7660                                         this->irelative_rel_, 0, 0,
7661                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
7662                                         elfcpp::STV_HIDDEN, 0, true, true);
7663         }
7664     }
7665   return this->irelative_rel_;
7666 }
7667
7668
7669 // Return the PLT address for a global symbol.
7670
7671 template<bool big_endian>
7672 uint32_t
7673 Output_data_plt_arm<big_endian>::address_for_global(const Symbol* gsym) const
7674 {
7675   uint64_t begin_offset = 0;
7676   if (gsym->type() == elfcpp::STT_GNU_IFUNC
7677       && gsym->can_use_relative_reloc(false))
7678     {
7679       begin_offset = (this->first_plt_entry_offset() +
7680                       this->count_ * this->get_plt_entry_size());
7681     }
7682   return this->address() + begin_offset + gsym->plt_offset();
7683 }
7684
7685
7686 // Return the PLT address for a local symbol.  These are always
7687 // IRELATIVE relocs.
7688
7689 template<bool big_endian>
7690 uint32_t
7691 Output_data_plt_arm<big_endian>::address_for_local(
7692     const Relobj* object,
7693     unsigned int r_sym) const
7694 {
7695   return (this->address()
7696           + this->first_plt_entry_offset()
7697           + this->count_ * this->get_plt_entry_size()
7698           + object->local_plt_offset(r_sym));
7699 }
7700
7701
7702 template<bool big_endian>
7703 class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
7704 {
7705  public:
7706   Output_data_plt_arm_standard(Layout* layout,
7707                                Arm_output_data_got<big_endian>* got,
7708                                Output_data_space* got_plt,
7709                                Output_data_space* got_irelative)
7710     : Output_data_plt_arm<big_endian>(layout, 4, got, got_plt, got_irelative)
7711   { }
7712
7713  protected:
7714   // Return the offset of the first non-reserved PLT entry.
7715   virtual unsigned int
7716   do_first_plt_entry_offset() const
7717   { return sizeof(first_plt_entry); }
7718
7719   // Return the size of a PLT entry.
7720   virtual unsigned int
7721   do_get_plt_entry_size() const
7722   { return sizeof(plt_entry); }
7723
7724   virtual void
7725   do_fill_first_plt_entry(unsigned char* pov,
7726                           Arm_address got_address,
7727                           Arm_address plt_address);
7728
7729   virtual void
7730   do_fill_plt_entry(unsigned char* pov,
7731                     Arm_address got_address,
7732                     Arm_address plt_address,
7733                     unsigned int got_offset,
7734                     unsigned int plt_offset);
7735
7736  private:
7737   // Template for the first PLT entry.
7738   static const uint32_t first_plt_entry[5];
7739
7740   // Template for subsequent PLT entries.
7741   static const uint32_t plt_entry[3];
7742 };
7743
7744 // ARM PLTs.
7745 // FIXME:  This is not very flexible.  Right now this has only been tested
7746 // on armv5te.  If we are to support additional architecture features like
7747 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7748
7749 // The first entry in the PLT.
7750 template<bool big_endian>
7751 const uint32_t Output_data_plt_arm_standard<big_endian>::first_plt_entry[5] =
7752 {
7753   0xe52de004,   // str   lr, [sp, #-4]!
7754   0xe59fe004,   // ldr   lr, [pc, #4]
7755   0xe08fe00e,   // add   lr, pc, lr
7756   0xe5bef008,   // ldr   pc, [lr, #8]!
7757   0x00000000,   // &GOT[0] - .
7758 };
7759
7760 template<bool big_endian>
7761 void
7762 Output_data_plt_arm_standard<big_endian>::do_fill_first_plt_entry(
7763     unsigned char* pov,
7764     Arm_address got_address,
7765     Arm_address plt_address)
7766 {
7767   // Write first PLT entry.  All but the last word are constants.
7768   const size_t num_first_plt_words = (sizeof(first_plt_entry)
7769                                       / sizeof(plt_entry[0]));
7770   for (size_t i = 0; i < num_first_plt_words - 1; i++)
7771     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7772   // Last word in first PLT entry is &GOT[0] - .
7773   elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7774                                          got_address - (plt_address + 16));
7775 }
7776
7777 // Subsequent entries in the PLT.
7778
7779 template<bool big_endian>
7780 const uint32_t Output_data_plt_arm_standard<big_endian>::plt_entry[3] =
7781 {
7782   0xe28fc600,   // add   ip, pc, #0xNN00000
7783   0xe28cca00,   // add   ip, ip, #0xNN000
7784   0xe5bcf000,   // ldr   pc, [ip, #0xNNN]!
7785 };
7786
7787 template<bool big_endian>
7788 void
7789 Output_data_plt_arm_standard<big_endian>::do_fill_plt_entry(
7790     unsigned char* pov,
7791     Arm_address got_address,
7792     Arm_address plt_address,
7793     unsigned int got_offset,
7794     unsigned int plt_offset)
7795 {
7796   int32_t offset = ((got_address + got_offset)
7797                     - (plt_address + plt_offset + 8));
7798
7799   gold_assert(offset >= 0 && offset < 0x0fffffff);
7800   uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7801   elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7802   uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7803   elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7804   uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7805   elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7806 }
7807
7808 // Write out the PLT.  This uses the hand-coded instructions above,
7809 // and adjusts them as needed.  This is all specified by the arm ELF
7810 // Processor Supplement.
7811
7812 template<bool big_endian>
7813 void
7814 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7815 {
7816   const off_t offset = this->offset();
7817   const section_size_type oview_size =
7818     convert_to_section_size_type(this->data_size());
7819   unsigned char* const oview = of->get_output_view(offset, oview_size);
7820
7821   const off_t got_file_offset = this->got_plt_->offset();
7822   gold_assert(got_file_offset + this->got_plt_->data_size()
7823               == this->got_irelative_->offset());
7824   const section_size_type got_size =
7825     convert_to_section_size_type(this->got_plt_->data_size()
7826                                  + this->got_irelative_->data_size());
7827   unsigned char* const got_view = of->get_output_view(got_file_offset,
7828                                                       got_size);
7829   unsigned char* pov = oview;
7830
7831   Arm_address plt_address = this->address();
7832   Arm_address got_address = this->got_plt_->address();
7833
7834   // Write first PLT entry.
7835   this->fill_first_plt_entry(pov, got_address, plt_address);
7836   pov += this->first_plt_entry_offset();
7837
7838   unsigned char* got_pov = got_view;
7839
7840   memset(got_pov, 0, 12);
7841   got_pov += 12;
7842
7843   unsigned int plt_offset = this->first_plt_entry_offset();
7844   unsigned int got_offset = 12;
7845   const unsigned int count = this->count_ + this->irelative_count_;
7846   gold_assert(this->irelative_count_ == this->irelative_data_vec_.size());
7847   for (unsigned int i = 0;
7848        i < count;
7849        ++i,
7850          pov += this->get_plt_entry_size(),
7851          got_pov += 4,
7852          plt_offset += this->get_plt_entry_size(),
7853          got_offset += 4)
7854     {
7855       // Set and adjust the PLT entry itself.
7856       this->fill_plt_entry(pov, got_address, plt_address,
7857                            got_offset, plt_offset);
7858
7859       Arm_address value;
7860       if (i < this->count_)
7861         {
7862           // For non-irelative got entries, the value is the beginning of plt.
7863           value = plt_address;
7864         }
7865       else
7866         {
7867           // For irelative got entries, the value is the (global/local) symbol
7868           // address.
7869           const IRelative_data& idata =
7870               this->irelative_data_vec_[i - this->count_];
7871           if (idata.symbol_is_global_)
7872             {
7873               // Set the entry in the GOT for irelative symbols.  The content is
7874               // the address of the ifunc, not the address of plt start.
7875               const Sized_symbol<32>* sized_symbol = idata.u_.global;
7876               gold_assert(sized_symbol->type() == elfcpp::STT_GNU_IFUNC);
7877               value = sized_symbol->value();
7878             }
7879           else
7880             {
7881               value = idata.u_.local.relobj->local_symbol_value(
7882                   idata.u_.local.index, 0);
7883             }
7884         }
7885       elfcpp::Swap<32, big_endian>::writeval(got_pov, value);
7886     }
7887
7888   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7889   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7890
7891   of->write_output_view(offset, oview_size, oview);
7892   of->write_output_view(got_file_offset, got_size, got_view);
7893 }
7894
7895
7896 // Create a PLT entry for a global symbol.
7897
7898 template<bool big_endian>
7899 void
7900 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7901                                        Symbol* gsym)
7902 {
7903   if (gsym->has_plt_offset())
7904     return;
7905
7906   if (this->plt_ == NULL)
7907     this->make_plt_section(symtab, layout);
7908
7909   this->plt_->add_entry(symtab, layout, gsym);
7910 }
7911
7912
7913 // Create the PLT section.
7914 template<bool big_endian>
7915 void
7916 Target_arm<big_endian>::make_plt_section(
7917   Symbol_table* symtab, Layout* layout)
7918 {
7919   if (this->plt_ == NULL)
7920     {
7921       // Create the GOT section first.
7922       this->got_section(symtab, layout);
7923
7924       // GOT for irelatives is create along with got.plt.
7925       gold_assert(this->got_ != NULL
7926                   && this->got_plt_ != NULL
7927                   && this->got_irelative_ != NULL);
7928       this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_,
7929                                        this->got_irelative_);
7930
7931       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7932                                       (elfcpp::SHF_ALLOC
7933                                        | elfcpp::SHF_EXECINSTR),
7934                                       this->plt_, ORDER_PLT, false);
7935       symtab->define_in_output_data("$a", NULL,
7936                                     Symbol_table::PREDEFINED,
7937                                     this->plt_,
7938                                     0, 0, elfcpp::STT_NOTYPE,
7939                                     elfcpp::STB_LOCAL,
7940                                     elfcpp::STV_DEFAULT, 0,
7941                                     false, false);
7942     }
7943 }
7944
7945
7946 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
7947
7948 template<bool big_endian>
7949 void
7950 Target_arm<big_endian>::make_local_ifunc_plt_entry(
7951     Symbol_table* symtab, Layout* layout,
7952     Sized_relobj_file<32, big_endian>* relobj,
7953     unsigned int local_sym_index)
7954 {
7955   if (relobj->local_has_plt_offset(local_sym_index))
7956     return;
7957   if (this->plt_ == NULL)
7958     this->make_plt_section(symtab, layout);
7959   unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
7960                                                               relobj,
7961                                                               local_sym_index);
7962   relobj->set_local_plt_offset(local_sym_index, plt_offset);
7963 }
7964
7965
7966 // Return the number of entries in the PLT.
7967
7968 template<bool big_endian>
7969 unsigned int
7970 Target_arm<big_endian>::plt_entry_count() const
7971 {
7972   if (this->plt_ == NULL)
7973     return 0;
7974   return this->plt_->entry_count();
7975 }
7976
7977 // Return the offset of the first non-reserved PLT entry.
7978
7979 template<bool big_endian>
7980 unsigned int
7981 Target_arm<big_endian>::first_plt_entry_offset() const
7982 {
7983   return this->plt_->first_plt_entry_offset();
7984 }
7985
7986 // Return the size of each PLT entry.
7987
7988 template<bool big_endian>
7989 unsigned int
7990 Target_arm<big_endian>::plt_entry_size() const
7991 {
7992   return this->plt_->get_plt_entry_size();
7993 }
7994
7995 // Get the section to use for TLS_DESC relocations.
7996
7997 template<bool big_endian>
7998 typename Target_arm<big_endian>::Reloc_section*
7999 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
8000 {
8001   return this->plt_section()->rel_tls_desc(layout);
8002 }
8003
8004 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
8005
8006 template<bool big_endian>
8007 void
8008 Target_arm<big_endian>::define_tls_base_symbol(
8009     Symbol_table* symtab,
8010     Layout* layout)
8011 {
8012   if (this->tls_base_symbol_defined_)
8013     return;
8014
8015   Output_segment* tls_segment = layout->tls_segment();
8016   if (tls_segment != NULL)
8017     {
8018       bool is_exec = parameters->options().output_is_executable();
8019       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
8020                                        Symbol_table::PREDEFINED,
8021                                        tls_segment, 0, 0,
8022                                        elfcpp::STT_TLS,
8023                                        elfcpp::STB_LOCAL,
8024                                        elfcpp::STV_HIDDEN, 0,
8025                                        (is_exec
8026                                         ? Symbol::SEGMENT_END
8027                                         : Symbol::SEGMENT_START),
8028                                        true);
8029     }
8030   this->tls_base_symbol_defined_ = true;
8031 }
8032
8033 // Create a GOT entry for the TLS module index.
8034
8035 template<bool big_endian>
8036 unsigned int
8037 Target_arm<big_endian>::got_mod_index_entry(
8038     Symbol_table* symtab,
8039     Layout* layout,
8040     Sized_relobj_file<32, big_endian>* object)
8041 {
8042   if (this->got_mod_index_offset_ == -1U)
8043     {
8044       gold_assert(symtab != NULL && layout != NULL && object != NULL);
8045       Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
8046       unsigned int got_offset;
8047       if (!parameters->doing_static_link())
8048         {
8049           got_offset = got->add_constant(0);
8050           Reloc_section* rel_dyn = this->rel_dyn_section(layout);
8051           rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
8052                              got_offset);
8053         }
8054       else
8055         {
8056           // We are doing a static link.  Just mark it as belong to module 1,
8057           // the executable.
8058           got_offset = got->add_constant(1);
8059         }
8060
8061       got->add_constant(0);
8062       this->got_mod_index_offset_ = got_offset;
8063     }
8064   return this->got_mod_index_offset_;
8065 }
8066
8067 // Optimize the TLS relocation type based on what we know about the
8068 // symbol.  IS_FINAL is true if the final address of this symbol is
8069 // known at link time.
8070
8071 template<bool big_endian>
8072 tls::Tls_optimization
8073 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
8074 {
8075   // FIXME: Currently we do not do any TLS optimization.
8076   return tls::TLSOPT_NONE;
8077 }
8078
8079 // Get the Reference_flags for a particular relocation.
8080
8081 template<bool big_endian>
8082 int
8083 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
8084 {
8085   switch (r_type)
8086     {
8087     case elfcpp::R_ARM_NONE:
8088     case elfcpp::R_ARM_V4BX:
8089     case elfcpp::R_ARM_GNU_VTENTRY:
8090     case elfcpp::R_ARM_GNU_VTINHERIT:
8091       // No symbol reference.
8092       return 0;
8093
8094     case elfcpp::R_ARM_ABS32:
8095     case elfcpp::R_ARM_ABS16:
8096     case elfcpp::R_ARM_ABS12:
8097     case elfcpp::R_ARM_THM_ABS5:
8098     case elfcpp::R_ARM_ABS8:
8099     case elfcpp::R_ARM_BASE_ABS:
8100     case elfcpp::R_ARM_MOVW_ABS_NC:
8101     case elfcpp::R_ARM_MOVT_ABS:
8102     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8103     case elfcpp::R_ARM_THM_MOVT_ABS:
8104     case elfcpp::R_ARM_ABS32_NOI:
8105       return Symbol::ABSOLUTE_REF;
8106
8107     case elfcpp::R_ARM_REL32:
8108     case elfcpp::R_ARM_LDR_PC_G0:
8109     case elfcpp::R_ARM_SBREL32:
8110     case elfcpp::R_ARM_THM_PC8:
8111     case elfcpp::R_ARM_BASE_PREL:
8112     case elfcpp::R_ARM_MOVW_PREL_NC:
8113     case elfcpp::R_ARM_MOVT_PREL:
8114     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8115     case elfcpp::R_ARM_THM_MOVT_PREL:
8116     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8117     case elfcpp::R_ARM_THM_PC12:
8118     case elfcpp::R_ARM_REL32_NOI:
8119     case elfcpp::R_ARM_ALU_PC_G0_NC:
8120     case elfcpp::R_ARM_ALU_PC_G0:
8121     case elfcpp::R_ARM_ALU_PC_G1_NC:
8122     case elfcpp::R_ARM_ALU_PC_G1:
8123     case elfcpp::R_ARM_ALU_PC_G2:
8124     case elfcpp::R_ARM_LDR_PC_G1:
8125     case elfcpp::R_ARM_LDR_PC_G2:
8126     case elfcpp::R_ARM_LDRS_PC_G0:
8127     case elfcpp::R_ARM_LDRS_PC_G1:
8128     case elfcpp::R_ARM_LDRS_PC_G2:
8129     case elfcpp::R_ARM_LDC_PC_G0:
8130     case elfcpp::R_ARM_LDC_PC_G1:
8131     case elfcpp::R_ARM_LDC_PC_G2:
8132     case elfcpp::R_ARM_ALU_SB_G0_NC:
8133     case elfcpp::R_ARM_ALU_SB_G0:
8134     case elfcpp::R_ARM_ALU_SB_G1_NC:
8135     case elfcpp::R_ARM_ALU_SB_G1:
8136     case elfcpp::R_ARM_ALU_SB_G2:
8137     case elfcpp::R_ARM_LDR_SB_G0:
8138     case elfcpp::R_ARM_LDR_SB_G1:
8139     case elfcpp::R_ARM_LDR_SB_G2:
8140     case elfcpp::R_ARM_LDRS_SB_G0:
8141     case elfcpp::R_ARM_LDRS_SB_G1:
8142     case elfcpp::R_ARM_LDRS_SB_G2:
8143     case elfcpp::R_ARM_LDC_SB_G0:
8144     case elfcpp::R_ARM_LDC_SB_G1:
8145     case elfcpp::R_ARM_LDC_SB_G2:
8146     case elfcpp::R_ARM_MOVW_BREL_NC:
8147     case elfcpp::R_ARM_MOVT_BREL:
8148     case elfcpp::R_ARM_MOVW_BREL:
8149     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8150     case elfcpp::R_ARM_THM_MOVT_BREL:
8151     case elfcpp::R_ARM_THM_MOVW_BREL:
8152     case elfcpp::R_ARM_GOTOFF32:
8153     case elfcpp::R_ARM_GOTOFF12:
8154     case elfcpp::R_ARM_SBREL31:
8155       return Symbol::RELATIVE_REF;
8156
8157     case elfcpp::R_ARM_PLT32:
8158     case elfcpp::R_ARM_CALL:
8159     case elfcpp::R_ARM_JUMP24:
8160     case elfcpp::R_ARM_THM_CALL:
8161     case elfcpp::R_ARM_THM_JUMP24:
8162     case elfcpp::R_ARM_THM_JUMP19:
8163     case elfcpp::R_ARM_THM_JUMP6:
8164     case elfcpp::R_ARM_THM_JUMP11:
8165     case elfcpp::R_ARM_THM_JUMP8:
8166     // R_ARM_PREL31 is not used to relocate call/jump instructions but
8167     // in unwind tables. It may point to functions via PLTs.
8168     // So we treat it like call/jump relocations above.
8169     case elfcpp::R_ARM_PREL31:
8170       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
8171
8172     case elfcpp::R_ARM_GOT_BREL:
8173     case elfcpp::R_ARM_GOT_ABS:
8174     case elfcpp::R_ARM_GOT_PREL:
8175       // Absolute in GOT.
8176       return Symbol::ABSOLUTE_REF;
8177
8178     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8179     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8180     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8181     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8182     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8183       return Symbol::TLS_REF;
8184
8185     case elfcpp::R_ARM_TARGET1:
8186     case elfcpp::R_ARM_TARGET2:
8187     case elfcpp::R_ARM_COPY:
8188     case elfcpp::R_ARM_GLOB_DAT:
8189     case elfcpp::R_ARM_JUMP_SLOT:
8190     case elfcpp::R_ARM_RELATIVE:
8191     case elfcpp::R_ARM_PC24:
8192     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8193     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8194     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8195     default:
8196       // Not expected.  We will give an error later.
8197       return 0;
8198     }
8199 }
8200
8201 // Report an unsupported relocation against a local symbol.
8202
8203 template<bool big_endian>
8204 void
8205 Target_arm<big_endian>::Scan::unsupported_reloc_local(
8206     Sized_relobj_file<32, big_endian>* object,
8207     unsigned int r_type)
8208 {
8209   gold_error(_("%s: unsupported reloc %u against local symbol"),
8210              object->name().c_str(), r_type);
8211 }
8212
8213 // We are about to emit a dynamic relocation of type R_TYPE.  If the
8214 // dynamic linker does not support it, issue an error.  The GNU linker
8215 // only issues a non-PIC error for an allocated read-only section.
8216 // Here we know the section is allocated, but we don't know that it is
8217 // read-only.  But we check for all the relocation types which the
8218 // glibc dynamic linker supports, so it seems appropriate to issue an
8219 // error even if the section is not read-only.
8220
8221 template<bool big_endian>
8222 void
8223 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
8224                                             unsigned int r_type)
8225 {
8226   switch (r_type)
8227     {
8228     // These are the relocation types supported by glibc for ARM.
8229     case elfcpp::R_ARM_RELATIVE:
8230     case elfcpp::R_ARM_COPY:
8231     case elfcpp::R_ARM_GLOB_DAT:
8232     case elfcpp::R_ARM_JUMP_SLOT:
8233     case elfcpp::R_ARM_ABS32:
8234     case elfcpp::R_ARM_ABS32_NOI:
8235     case elfcpp::R_ARM_IRELATIVE:
8236     case elfcpp::R_ARM_PC24:
8237     // FIXME: The following 3 types are not supported by Android's dynamic
8238     // linker.
8239     case elfcpp::R_ARM_TLS_DTPMOD32:
8240     case elfcpp::R_ARM_TLS_DTPOFF32:
8241     case elfcpp::R_ARM_TLS_TPOFF32:
8242       return;
8243
8244     default:
8245       {
8246         // This prevents us from issuing more than one error per reloc
8247         // section.  But we can still wind up issuing more than one
8248         // error per object file.
8249         if (this->issued_non_pic_error_)
8250           return;
8251         const Arm_reloc_property* reloc_property =
8252           arm_reloc_property_table->get_reloc_property(r_type);
8253         gold_assert(reloc_property != NULL);
8254         object->error(_("requires unsupported dynamic reloc %s; "
8255                       "recompile with -fPIC"),
8256                       reloc_property->name().c_str());
8257         this->issued_non_pic_error_ = true;
8258         return;
8259       }
8260
8261     case elfcpp::R_ARM_NONE:
8262       gold_unreachable();
8263     }
8264 }
8265
8266
8267 // Return whether we need to make a PLT entry for a relocation of the
8268 // given type against a STT_GNU_IFUNC symbol.
8269
8270 template<bool big_endian>
8271 bool
8272 Target_arm<big_endian>::Scan::reloc_needs_plt_for_ifunc(
8273     Sized_relobj_file<32, big_endian>* object,
8274     unsigned int r_type)
8275 {
8276   int flags = Scan::get_reference_flags(r_type);
8277   if (flags & Symbol::TLS_REF)
8278     {
8279       gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
8280                  object->name().c_str(), r_type);
8281       return false;
8282     }
8283   return flags != 0;
8284 }
8285
8286
8287 // Scan a relocation for a local symbol.
8288 // FIXME: This only handles a subset of relocation types used by Android
8289 // on ARM v5te devices.
8290
8291 template<bool big_endian>
8292 inline void
8293 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
8294                                     Layout* layout,
8295                                     Target_arm* target,
8296                                     Sized_relobj_file<32, big_endian>* object,
8297                                     unsigned int data_shndx,
8298                                     Output_section* output_section,
8299                                     const elfcpp::Rel<32, big_endian>& reloc,
8300                                     unsigned int r_type,
8301                                     const elfcpp::Sym<32, big_endian>& lsym,
8302                                     bool is_discarded)
8303 {
8304   if (is_discarded)
8305     return;
8306
8307   r_type = get_real_reloc_type(r_type);
8308
8309   // A local STT_GNU_IFUNC symbol may require a PLT entry.
8310   bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
8311   if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
8312     {
8313       unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8314       target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
8315     }
8316
8317   switch (r_type)
8318     {
8319     case elfcpp::R_ARM_NONE:
8320     case elfcpp::R_ARM_V4BX:
8321     case elfcpp::R_ARM_GNU_VTENTRY:
8322     case elfcpp::R_ARM_GNU_VTINHERIT:
8323       break;
8324
8325     case elfcpp::R_ARM_ABS32:
8326     case elfcpp::R_ARM_ABS32_NOI:
8327       // If building a shared library (or a position-independent
8328       // executable), we need to create a dynamic relocation for
8329       // this location. The relocation applied at link time will
8330       // apply the link-time value, so we flag the location with
8331       // an R_ARM_RELATIVE relocation so the dynamic loader can
8332       // relocate it easily.
8333       if (parameters->options().output_is_position_independent())
8334         {
8335           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8336           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8337           // If we are to add more other reloc types than R_ARM_ABS32,
8338           // we need to add check_non_pic(object, r_type) here.
8339           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
8340                                       output_section, data_shndx,
8341                                       reloc.get_r_offset(), is_ifunc);
8342         }
8343       break;
8344
8345     case elfcpp::R_ARM_ABS16:
8346     case elfcpp::R_ARM_ABS12:
8347     case elfcpp::R_ARM_THM_ABS5:
8348     case elfcpp::R_ARM_ABS8:
8349     case elfcpp::R_ARM_BASE_ABS:
8350     case elfcpp::R_ARM_MOVW_ABS_NC:
8351     case elfcpp::R_ARM_MOVT_ABS:
8352     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8353     case elfcpp::R_ARM_THM_MOVT_ABS:
8354       // If building a shared library (or a position-independent
8355       // executable), we need to create a dynamic relocation for
8356       // this location. Because the addend needs to remain in the
8357       // data section, we need to be careful not to apply this
8358       // relocation statically.
8359       if (parameters->options().output_is_position_independent())
8360         {
8361           check_non_pic(object, r_type);
8362           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8363           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8364           if (lsym.get_st_type() != elfcpp::STT_SECTION)
8365             rel_dyn->add_local(object, r_sym, r_type, output_section,
8366                                data_shndx, reloc.get_r_offset());
8367           else
8368             {
8369               gold_assert(lsym.get_st_value() == 0);
8370               unsigned int shndx = lsym.get_st_shndx();
8371               bool is_ordinary;
8372               shndx = object->adjust_sym_shndx(r_sym, shndx,
8373                                                &is_ordinary);
8374               if (!is_ordinary)
8375                 object->error(_("section symbol %u has bad shndx %u"),
8376                               r_sym, shndx);
8377               else
8378                 rel_dyn->add_local_section(object, shndx,
8379                                            r_type, output_section,
8380                                            data_shndx, reloc.get_r_offset());
8381             }
8382         }
8383       break;
8384
8385     case elfcpp::R_ARM_REL32:
8386     case elfcpp::R_ARM_LDR_PC_G0:
8387     case elfcpp::R_ARM_SBREL32:
8388     case elfcpp::R_ARM_THM_CALL:
8389     case elfcpp::R_ARM_THM_PC8:
8390     case elfcpp::R_ARM_BASE_PREL:
8391     case elfcpp::R_ARM_PLT32:
8392     case elfcpp::R_ARM_CALL:
8393     case elfcpp::R_ARM_JUMP24:
8394     case elfcpp::R_ARM_THM_JUMP24:
8395     case elfcpp::R_ARM_SBREL31:
8396     case elfcpp::R_ARM_PREL31:
8397     case elfcpp::R_ARM_MOVW_PREL_NC:
8398     case elfcpp::R_ARM_MOVT_PREL:
8399     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8400     case elfcpp::R_ARM_THM_MOVT_PREL:
8401     case elfcpp::R_ARM_THM_JUMP19:
8402     case elfcpp::R_ARM_THM_JUMP6:
8403     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8404     case elfcpp::R_ARM_THM_PC12:
8405     case elfcpp::R_ARM_REL32_NOI:
8406     case elfcpp::R_ARM_ALU_PC_G0_NC:
8407     case elfcpp::R_ARM_ALU_PC_G0:
8408     case elfcpp::R_ARM_ALU_PC_G1_NC:
8409     case elfcpp::R_ARM_ALU_PC_G1:
8410     case elfcpp::R_ARM_ALU_PC_G2:
8411     case elfcpp::R_ARM_LDR_PC_G1:
8412     case elfcpp::R_ARM_LDR_PC_G2:
8413     case elfcpp::R_ARM_LDRS_PC_G0:
8414     case elfcpp::R_ARM_LDRS_PC_G1:
8415     case elfcpp::R_ARM_LDRS_PC_G2:
8416     case elfcpp::R_ARM_LDC_PC_G0:
8417     case elfcpp::R_ARM_LDC_PC_G1:
8418     case elfcpp::R_ARM_LDC_PC_G2:
8419     case elfcpp::R_ARM_ALU_SB_G0_NC:
8420     case elfcpp::R_ARM_ALU_SB_G0:
8421     case elfcpp::R_ARM_ALU_SB_G1_NC:
8422     case elfcpp::R_ARM_ALU_SB_G1:
8423     case elfcpp::R_ARM_ALU_SB_G2:
8424     case elfcpp::R_ARM_LDR_SB_G0:
8425     case elfcpp::R_ARM_LDR_SB_G1:
8426     case elfcpp::R_ARM_LDR_SB_G2:
8427     case elfcpp::R_ARM_LDRS_SB_G0:
8428     case elfcpp::R_ARM_LDRS_SB_G1:
8429     case elfcpp::R_ARM_LDRS_SB_G2:
8430     case elfcpp::R_ARM_LDC_SB_G0:
8431     case elfcpp::R_ARM_LDC_SB_G1:
8432     case elfcpp::R_ARM_LDC_SB_G2:
8433     case elfcpp::R_ARM_MOVW_BREL_NC:
8434     case elfcpp::R_ARM_MOVT_BREL:
8435     case elfcpp::R_ARM_MOVW_BREL:
8436     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8437     case elfcpp::R_ARM_THM_MOVT_BREL:
8438     case elfcpp::R_ARM_THM_MOVW_BREL:
8439     case elfcpp::R_ARM_THM_JUMP11:
8440     case elfcpp::R_ARM_THM_JUMP8:
8441       // We don't need to do anything for a relative addressing relocation
8442       // against a local symbol if it does not reference the GOT.
8443       break;
8444
8445     case elfcpp::R_ARM_GOTOFF32:
8446     case elfcpp::R_ARM_GOTOFF12:
8447       // We need a GOT section:
8448       target->got_section(symtab, layout);
8449       break;
8450
8451     case elfcpp::R_ARM_GOT_BREL:
8452     case elfcpp::R_ARM_GOT_PREL:
8453       {
8454         // The symbol requires a GOT entry.
8455         Arm_output_data_got<big_endian>* got =
8456           target->got_section(symtab, layout);
8457         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8458         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
8459           {
8460             // If we are generating a shared object, we need to add a
8461             // dynamic RELATIVE relocation for this symbol's GOT entry.
8462             if (parameters->options().output_is_position_independent())
8463               {
8464                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8465                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8466                 rel_dyn->add_local_relative(
8467                     object, r_sym, elfcpp::R_ARM_RELATIVE, got,
8468                     object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
8469               }
8470           }
8471       }
8472       break;
8473
8474     case elfcpp::R_ARM_TARGET1:
8475     case elfcpp::R_ARM_TARGET2:
8476       // This should have been mapped to another type already.
8477       // Fall through.
8478     case elfcpp::R_ARM_COPY:
8479     case elfcpp::R_ARM_GLOB_DAT:
8480     case elfcpp::R_ARM_JUMP_SLOT:
8481     case elfcpp::R_ARM_RELATIVE:
8482       // These are relocations which should only be seen by the
8483       // dynamic linker, and should never be seen here.
8484       gold_error(_("%s: unexpected reloc %u in object file"),
8485                  object->name().c_str(), r_type);
8486       break;
8487
8488
8489       // These are initial TLS relocs, which are expected when
8490       // linking.
8491     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8492     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8493     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8494     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8495     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8496       {
8497         bool output_is_shared = parameters->options().shared();
8498         const tls::Tls_optimization optimized_type
8499             = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
8500                                                          r_type);
8501         switch (r_type)
8502           {
8503           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8504             if (optimized_type == tls::TLSOPT_NONE)
8505               {
8506                 // Create a pair of GOT entries for the module index and
8507                 // dtv-relative offset.
8508                 Arm_output_data_got<big_endian>* got
8509                     = target->got_section(symtab, layout);
8510                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8511                 unsigned int shndx = lsym.get_st_shndx();
8512                 bool is_ordinary;
8513                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
8514                 if (!is_ordinary)
8515                   {
8516                     object->error(_("local symbol %u has bad shndx %u"),
8517                                   r_sym, shndx);
8518                     break;
8519                   }
8520
8521                 if (!parameters->doing_static_link())
8522                   got->add_local_pair_with_rel(object, r_sym, shndx,
8523                                                GOT_TYPE_TLS_PAIR,
8524                                                target->rel_dyn_section(layout),
8525                                                elfcpp::R_ARM_TLS_DTPMOD32);
8526                 else
8527                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
8528                                                       object, r_sym);
8529               }
8530             else
8531               // FIXME: TLS optimization not supported yet.
8532               gold_unreachable();
8533             break;
8534
8535           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
8536             if (optimized_type == tls::TLSOPT_NONE)
8537               {
8538                 // Create a GOT entry for the module index.
8539                 target->got_mod_index_entry(symtab, layout, object);
8540               }
8541             else
8542               // FIXME: TLS optimization not supported yet.
8543               gold_unreachable();
8544             break;
8545
8546           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
8547             break;
8548
8549           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
8550             layout->set_has_static_tls();
8551             if (optimized_type == tls::TLSOPT_NONE)
8552               {
8553                 // Create a GOT entry for the tp-relative offset.
8554                 Arm_output_data_got<big_endian>* got
8555                   = target->got_section(symtab, layout);
8556                 unsigned int r_sym =
8557                    elfcpp::elf_r_sym<32>(reloc.get_r_info());
8558                 if (!parameters->doing_static_link())
8559                     got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
8560                                             target->rel_dyn_section(layout),
8561                                             elfcpp::R_ARM_TLS_TPOFF32);
8562                 else if (!object->local_has_got_offset(r_sym,
8563                                                        GOT_TYPE_TLS_OFFSET))
8564                   {
8565                     got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
8566                     unsigned int got_offset =
8567                       object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
8568                     got->add_static_reloc(got_offset,
8569                                           elfcpp::R_ARM_TLS_TPOFF32, object,
8570                                           r_sym);
8571                   }
8572               }
8573             else
8574               // FIXME: TLS optimization not supported yet.
8575               gold_unreachable();
8576             break;
8577
8578           case elfcpp::R_ARM_TLS_LE32:          // Local-exec
8579             layout->set_has_static_tls();
8580             if (output_is_shared)
8581               {
8582                 // We need to create a dynamic relocation.
8583                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8584                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8585                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8586                 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8587                                    output_section, data_shndx,
8588                                    reloc.get_r_offset());
8589               }
8590             break;
8591
8592           default:
8593             gold_unreachable();
8594           }
8595       }
8596       break;
8597
8598     case elfcpp::R_ARM_PC24:
8599     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8600     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8601     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8602     default:
8603       unsupported_reloc_local(object, r_type);
8604       break;
8605     }
8606 }
8607
8608 // Report an unsupported relocation against a global symbol.
8609
8610 template<bool big_endian>
8611 void
8612 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8613     Sized_relobj_file<32, big_endian>* object,
8614     unsigned int r_type,
8615     Symbol* gsym)
8616 {
8617   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8618              object->name().c_str(), r_type, gsym->demangled_name().c_str());
8619 }
8620
8621 template<bool big_endian>
8622 inline bool
8623 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8624     unsigned int r_type)
8625 {
8626   switch (r_type)
8627     {
8628     case elfcpp::R_ARM_PC24:
8629     case elfcpp::R_ARM_THM_CALL:
8630     case elfcpp::R_ARM_PLT32:
8631     case elfcpp::R_ARM_CALL:
8632     case elfcpp::R_ARM_JUMP24:
8633     case elfcpp::R_ARM_THM_JUMP24:
8634     case elfcpp::R_ARM_SBREL31:
8635     case elfcpp::R_ARM_PREL31:
8636     case elfcpp::R_ARM_THM_JUMP19:
8637     case elfcpp::R_ARM_THM_JUMP6:
8638     case elfcpp::R_ARM_THM_JUMP11:
8639     case elfcpp::R_ARM_THM_JUMP8:
8640       // All the relocations above are branches except SBREL31 and PREL31.
8641       return false;
8642
8643     default:
8644       // Be conservative and assume this is a function pointer.
8645       return true;
8646     }
8647 }
8648
8649 template<bool big_endian>
8650 inline bool
8651 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8652   Symbol_table*,
8653   Layout*,
8654   Target_arm<big_endian>* target,
8655   Sized_relobj_file<32, big_endian>*,
8656   unsigned int,
8657   Output_section*,
8658   const elfcpp::Rel<32, big_endian>&,
8659   unsigned int r_type,
8660   const elfcpp::Sym<32, big_endian>&)
8661 {
8662   r_type = target->get_real_reloc_type(r_type);
8663   return possible_function_pointer_reloc(r_type);
8664 }
8665
8666 template<bool big_endian>
8667 inline bool
8668 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8669   Symbol_table*,
8670   Layout*,
8671   Target_arm<big_endian>* target,
8672   Sized_relobj_file<32, big_endian>*,
8673   unsigned int,
8674   Output_section*,
8675   const elfcpp::Rel<32, big_endian>&,
8676   unsigned int r_type,
8677   Symbol* gsym)
8678 {
8679   // GOT is not a function.
8680   if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8681     return false;
8682
8683   r_type = target->get_real_reloc_type(r_type);
8684   return possible_function_pointer_reloc(r_type);
8685 }
8686
8687 // Scan a relocation for a global symbol.
8688
8689 template<bool big_endian>
8690 inline void
8691 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8692                                      Layout* layout,
8693                                      Target_arm* target,
8694                                      Sized_relobj_file<32, big_endian>* object,
8695                                      unsigned int data_shndx,
8696                                      Output_section* output_section,
8697                                      const elfcpp::Rel<32, big_endian>& reloc,
8698                                      unsigned int r_type,
8699                                      Symbol* gsym)
8700 {
8701   // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8702   // section.  We check here to avoid creating a dynamic reloc against
8703   // _GLOBAL_OFFSET_TABLE_.
8704   if (!target->has_got_section()
8705       && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8706     target->got_section(symtab, layout);
8707
8708   // A STT_GNU_IFUNC symbol may require a PLT entry.
8709   if (gsym->type() == elfcpp::STT_GNU_IFUNC
8710       && this->reloc_needs_plt_for_ifunc(object, r_type))
8711     target->make_plt_entry(symtab, layout, gsym);
8712
8713   r_type = get_real_reloc_type(r_type);
8714   switch (r_type)
8715     {
8716     case elfcpp::R_ARM_NONE:
8717     case elfcpp::R_ARM_V4BX:
8718     case elfcpp::R_ARM_GNU_VTENTRY:
8719     case elfcpp::R_ARM_GNU_VTINHERIT:
8720       break;
8721
8722     case elfcpp::R_ARM_ABS32:
8723     case elfcpp::R_ARM_ABS16:
8724     case elfcpp::R_ARM_ABS12:
8725     case elfcpp::R_ARM_THM_ABS5:
8726     case elfcpp::R_ARM_ABS8:
8727     case elfcpp::R_ARM_BASE_ABS:
8728     case elfcpp::R_ARM_MOVW_ABS_NC:
8729     case elfcpp::R_ARM_MOVT_ABS:
8730     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8731     case elfcpp::R_ARM_THM_MOVT_ABS:
8732     case elfcpp::R_ARM_ABS32_NOI:
8733       // Absolute addressing relocations.
8734       {
8735         // Make a PLT entry if necessary.
8736         if (this->symbol_needs_plt_entry(gsym))
8737           {
8738             target->make_plt_entry(symtab, layout, gsym);
8739             // Since this is not a PC-relative relocation, we may be
8740             // taking the address of a function. In that case we need to
8741             // set the entry in the dynamic symbol table to the address of
8742             // the PLT entry.
8743             if (gsym->is_from_dynobj() && !parameters->options().shared())
8744               gsym->set_needs_dynsym_value();
8745           }
8746         // Make a dynamic relocation if necessary.
8747         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8748           {
8749             if (!parameters->options().output_is_position_independent()
8750                 && gsym->may_need_copy_reloc())
8751               {
8752                 target->copy_reloc(symtab, layout, object,
8753                                    data_shndx, output_section, gsym, reloc);
8754               }
8755             else if ((r_type == elfcpp::R_ARM_ABS32
8756                       || r_type == elfcpp::R_ARM_ABS32_NOI)
8757                      && gsym->type() == elfcpp::STT_GNU_IFUNC
8758                      && gsym->can_use_relative_reloc(false)
8759                      && !gsym->is_from_dynobj()
8760                      && !gsym->is_undefined()
8761                      && !gsym->is_preemptible())
8762               {
8763                 // Use an IRELATIVE reloc for a locally defined STT_GNU_IFUNC
8764                 // symbol. This makes a function address in a PIE executable
8765                 // match the address in a shared library that it links against.
8766                 Reloc_section* rel_irelative =
8767                     target->rel_irelative_section(layout);
8768                 unsigned int r_type = elfcpp::R_ARM_IRELATIVE;
8769                 rel_irelative->add_symbolless_global_addend(
8770                     gsym, r_type, output_section, object,
8771                     data_shndx, reloc.get_r_offset());
8772               }
8773             else if ((r_type == elfcpp::R_ARM_ABS32
8774                       || r_type == elfcpp::R_ARM_ABS32_NOI)
8775                      && gsym->can_use_relative_reloc(false))
8776               {
8777                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8778                 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8779                                              output_section, object,
8780                                              data_shndx, reloc.get_r_offset());
8781               }
8782             else
8783               {
8784                 check_non_pic(object, r_type);
8785                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8786                 rel_dyn->add_global(gsym, r_type, output_section, object,
8787                                     data_shndx, reloc.get_r_offset());
8788               }
8789           }
8790       }
8791       break;
8792
8793     case elfcpp::R_ARM_GOTOFF32:
8794     case elfcpp::R_ARM_GOTOFF12:
8795       // We need a GOT section.
8796       target->got_section(symtab, layout);
8797       break;
8798
8799     case elfcpp::R_ARM_REL32:
8800     case elfcpp::R_ARM_LDR_PC_G0:
8801     case elfcpp::R_ARM_SBREL32:
8802     case elfcpp::R_ARM_THM_PC8:
8803     case elfcpp::R_ARM_BASE_PREL:
8804     case elfcpp::R_ARM_MOVW_PREL_NC:
8805     case elfcpp::R_ARM_MOVT_PREL:
8806     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8807     case elfcpp::R_ARM_THM_MOVT_PREL:
8808     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8809     case elfcpp::R_ARM_THM_PC12:
8810     case elfcpp::R_ARM_REL32_NOI:
8811     case elfcpp::R_ARM_ALU_PC_G0_NC:
8812     case elfcpp::R_ARM_ALU_PC_G0:
8813     case elfcpp::R_ARM_ALU_PC_G1_NC:
8814     case elfcpp::R_ARM_ALU_PC_G1:
8815     case elfcpp::R_ARM_ALU_PC_G2:
8816     case elfcpp::R_ARM_LDR_PC_G1:
8817     case elfcpp::R_ARM_LDR_PC_G2:
8818     case elfcpp::R_ARM_LDRS_PC_G0:
8819     case elfcpp::R_ARM_LDRS_PC_G1:
8820     case elfcpp::R_ARM_LDRS_PC_G2:
8821     case elfcpp::R_ARM_LDC_PC_G0:
8822     case elfcpp::R_ARM_LDC_PC_G1:
8823     case elfcpp::R_ARM_LDC_PC_G2:
8824     case elfcpp::R_ARM_ALU_SB_G0_NC:
8825     case elfcpp::R_ARM_ALU_SB_G0:
8826     case elfcpp::R_ARM_ALU_SB_G1_NC:
8827     case elfcpp::R_ARM_ALU_SB_G1:
8828     case elfcpp::R_ARM_ALU_SB_G2:
8829     case elfcpp::R_ARM_LDR_SB_G0:
8830     case elfcpp::R_ARM_LDR_SB_G1:
8831     case elfcpp::R_ARM_LDR_SB_G2:
8832     case elfcpp::R_ARM_LDRS_SB_G0:
8833     case elfcpp::R_ARM_LDRS_SB_G1:
8834     case elfcpp::R_ARM_LDRS_SB_G2:
8835     case elfcpp::R_ARM_LDC_SB_G0:
8836     case elfcpp::R_ARM_LDC_SB_G1:
8837     case elfcpp::R_ARM_LDC_SB_G2:
8838     case elfcpp::R_ARM_MOVW_BREL_NC:
8839     case elfcpp::R_ARM_MOVT_BREL:
8840     case elfcpp::R_ARM_MOVW_BREL:
8841     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8842     case elfcpp::R_ARM_THM_MOVT_BREL:
8843     case elfcpp::R_ARM_THM_MOVW_BREL:
8844       // Relative addressing relocations.
8845       {
8846         // Make a dynamic relocation if necessary.
8847         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8848           {
8849             if (parameters->options().output_is_executable()
8850                 && target->may_need_copy_reloc(gsym))
8851               {
8852                 target->copy_reloc(symtab, layout, object,
8853                                    data_shndx, output_section, gsym, reloc);
8854               }
8855             else
8856               {
8857                 check_non_pic(object, r_type);
8858                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8859                 rel_dyn->add_global(gsym, r_type, output_section, object,
8860                                     data_shndx, reloc.get_r_offset());
8861               }
8862           }
8863       }
8864       break;
8865
8866     case elfcpp::R_ARM_THM_CALL:
8867     case elfcpp::R_ARM_PLT32:
8868     case elfcpp::R_ARM_CALL:
8869     case elfcpp::R_ARM_JUMP24:
8870     case elfcpp::R_ARM_THM_JUMP24:
8871     case elfcpp::R_ARM_SBREL31:
8872     case elfcpp::R_ARM_PREL31:
8873     case elfcpp::R_ARM_THM_JUMP19:
8874     case elfcpp::R_ARM_THM_JUMP6:
8875     case elfcpp::R_ARM_THM_JUMP11:
8876     case elfcpp::R_ARM_THM_JUMP8:
8877       // All the relocation above are branches except for the PREL31 ones.
8878       // A PREL31 relocation can point to a personality function in a shared
8879       // library.  In that case we want to use a PLT because we want to
8880       // call the personality routine and the dynamic linkers we care about
8881       // do not support dynamic PREL31 relocations. An REL31 relocation may
8882       // point to a function whose unwinding behaviour is being described but
8883       // we will not mistakenly generate a PLT for that because we should use
8884       // a local section symbol.
8885
8886       // If the symbol is fully resolved, this is just a relative
8887       // local reloc.  Otherwise we need a PLT entry.
8888       if (gsym->final_value_is_known())
8889         break;
8890       // If building a shared library, we can also skip the PLT entry
8891       // if the symbol is defined in the output file and is protected
8892       // or hidden.
8893       if (gsym->is_defined()
8894           && !gsym->is_from_dynobj()
8895           && !gsym->is_preemptible())
8896         break;
8897       target->make_plt_entry(symtab, layout, gsym);
8898       break;
8899
8900     case elfcpp::R_ARM_GOT_BREL:
8901     case elfcpp::R_ARM_GOT_ABS:
8902     case elfcpp::R_ARM_GOT_PREL:
8903       {
8904         // The symbol requires a GOT entry.
8905         Arm_output_data_got<big_endian>* got =
8906           target->got_section(symtab, layout);
8907         if (gsym->final_value_is_known())
8908           {
8909             // For a STT_GNU_IFUNC symbol we want the PLT address.
8910             if (gsym->type() == elfcpp::STT_GNU_IFUNC)
8911               got->add_global_plt(gsym, GOT_TYPE_STANDARD);
8912             else
8913               got->add_global(gsym, GOT_TYPE_STANDARD);
8914           }
8915         else
8916           {
8917             // If this symbol is not fully resolved, we need to add a
8918             // GOT entry with a dynamic relocation.
8919             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8920             if (gsym->is_from_dynobj()
8921                 || gsym->is_undefined()
8922                 || gsym->is_preemptible()
8923                 || (gsym->visibility() == elfcpp::STV_PROTECTED
8924                     && parameters->options().shared())
8925                 || (gsym->type() == elfcpp::STT_GNU_IFUNC
8926                     && parameters->options().output_is_position_independent()))
8927               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8928                                        rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8929             else
8930               {
8931                 // For a STT_GNU_IFUNC symbol we want to write the PLT
8932                 // offset into the GOT, so that function pointer
8933                 // comparisons work correctly.
8934                 bool is_new;
8935                 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
8936                   is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
8937                 else
8938                   {
8939                     is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
8940                     // Tell the dynamic linker to use the PLT address
8941                     // when resolving relocations.
8942                     if (gsym->is_from_dynobj()
8943                         && !parameters->options().shared())
8944                       gsym->set_needs_dynsym_value();
8945                   }
8946                 if (is_new)
8947                   rel_dyn->add_global_relative(
8948                       gsym, elfcpp::R_ARM_RELATIVE, got,
8949                       gsym->got_offset(GOT_TYPE_STANDARD));
8950               }
8951           }
8952       }
8953       break;
8954
8955     case elfcpp::R_ARM_TARGET1:
8956     case elfcpp::R_ARM_TARGET2:
8957       // These should have been mapped to other types already.
8958       // Fall through.
8959     case elfcpp::R_ARM_COPY:
8960     case elfcpp::R_ARM_GLOB_DAT:
8961     case elfcpp::R_ARM_JUMP_SLOT:
8962     case elfcpp::R_ARM_RELATIVE:
8963       // These are relocations which should only be seen by the
8964       // dynamic linker, and should never be seen here.
8965       gold_error(_("%s: unexpected reloc %u in object file"),
8966                  object->name().c_str(), r_type);
8967       break;
8968
8969       // These are initial tls relocs, which are expected when
8970       // linking.
8971     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8972     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8973     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8974     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8975     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8976       {
8977         const bool is_final = gsym->final_value_is_known();
8978         const tls::Tls_optimization optimized_type
8979             = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8980         switch (r_type)
8981           {
8982           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8983             if (optimized_type == tls::TLSOPT_NONE)
8984               {
8985                 // Create a pair of GOT entries for the module index and
8986                 // dtv-relative offset.
8987                 Arm_output_data_got<big_endian>* got
8988                     = target->got_section(symtab, layout);
8989                 if (!parameters->doing_static_link())
8990                   got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8991                                                 target->rel_dyn_section(layout),
8992                                                 elfcpp::R_ARM_TLS_DTPMOD32,
8993                                                 elfcpp::R_ARM_TLS_DTPOFF32);
8994                 else
8995                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8996               }
8997             else
8998               // FIXME: TLS optimization not supported yet.
8999               gold_unreachable();
9000             break;
9001
9002           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
9003             if (optimized_type == tls::TLSOPT_NONE)
9004               {
9005                 // Create a GOT entry for the module index.
9006                 target->got_mod_index_entry(symtab, layout, object);
9007               }
9008             else
9009               // FIXME: TLS optimization not supported yet.
9010               gold_unreachable();
9011             break;
9012
9013           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
9014             break;
9015
9016           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
9017             layout->set_has_static_tls();
9018             if (optimized_type == tls::TLSOPT_NONE)
9019               {
9020                 // Create a GOT entry for the tp-relative offset.
9021                 Arm_output_data_got<big_endian>* got
9022                   = target->got_section(symtab, layout);
9023                 if (!parameters->doing_static_link())
9024                   got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
9025                                            target->rel_dyn_section(layout),
9026                                            elfcpp::R_ARM_TLS_TPOFF32);
9027                 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
9028                   {
9029                     got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
9030                     unsigned int got_offset =
9031                        gsym->got_offset(GOT_TYPE_TLS_OFFSET);
9032                     got->add_static_reloc(got_offset,
9033                                           elfcpp::R_ARM_TLS_TPOFF32, gsym);
9034                   }
9035               }
9036             else
9037               // FIXME: TLS optimization not supported yet.
9038               gold_unreachable();
9039             break;
9040
9041           case elfcpp::R_ARM_TLS_LE32:  // Local-exec
9042             layout->set_has_static_tls();
9043             if (parameters->options().shared())
9044               {
9045                 // We need to create a dynamic relocation.
9046                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
9047                 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
9048                                     output_section, object,
9049                                     data_shndx, reloc.get_r_offset());
9050               }
9051             break;
9052
9053           default:
9054             gold_unreachable();
9055           }
9056       }
9057       break;
9058
9059     case elfcpp::R_ARM_PC24:
9060     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9061     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9062     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9063     default:
9064       unsupported_reloc_global(object, r_type, gsym);
9065       break;
9066     }
9067 }
9068
9069 // Process relocations for gc.
9070
9071 template<bool big_endian>
9072 void
9073 Target_arm<big_endian>::gc_process_relocs(
9074     Symbol_table* symtab,
9075     Layout* layout,
9076     Sized_relobj_file<32, big_endian>* object,
9077     unsigned int data_shndx,
9078     unsigned int,
9079     const unsigned char* prelocs,
9080     size_t reloc_count,
9081     Output_section* output_section,
9082     bool needs_special_offset_handling,
9083     size_t local_symbol_count,
9084     const unsigned char* plocal_symbols)
9085 {
9086   typedef Target_arm<big_endian> Arm;
9087   typedef typename Target_arm<big_endian>::Scan Scan;
9088
9089   gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
9090                           typename Target_arm::Relocatable_size_for_reloc>(
9091     symtab,
9092     layout,
9093     this,
9094     object,
9095     data_shndx,
9096     prelocs,
9097     reloc_count,
9098     output_section,
9099     needs_special_offset_handling,
9100     local_symbol_count,
9101     plocal_symbols);
9102 }
9103
9104 // Scan relocations for a section.
9105
9106 template<bool big_endian>
9107 void
9108 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
9109                                     Layout* layout,
9110                                     Sized_relobj_file<32, big_endian>* object,
9111                                     unsigned int data_shndx,
9112                                     unsigned int sh_type,
9113                                     const unsigned char* prelocs,
9114                                     size_t reloc_count,
9115                                     Output_section* output_section,
9116                                     bool needs_special_offset_handling,
9117                                     size_t local_symbol_count,
9118                                     const unsigned char* plocal_symbols)
9119 {
9120   typedef typename Target_arm<big_endian>::Scan Scan;
9121   if (sh_type == elfcpp::SHT_RELA)
9122     {
9123       gold_error(_("%s: unsupported RELA reloc section"),
9124                  object->name().c_str());
9125       return;
9126     }
9127
9128   gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
9129     symtab,
9130     layout,
9131     this,
9132     object,
9133     data_shndx,
9134     prelocs,
9135     reloc_count,
9136     output_section,
9137     needs_special_offset_handling,
9138     local_symbol_count,
9139     plocal_symbols);
9140 }
9141
9142 // Finalize the sections.
9143
9144 template<bool big_endian>
9145 void
9146 Target_arm<big_endian>::do_finalize_sections(
9147     Layout* layout,
9148     const Input_objects* input_objects,
9149     Symbol_table*)
9150 {
9151   bool merged_any_attributes = false;
9152   // Merge processor-specific flags.
9153   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
9154        p != input_objects->relobj_end();
9155        ++p)
9156     {
9157       Arm_relobj<big_endian>* arm_relobj =
9158         Arm_relobj<big_endian>::as_arm_relobj(*p);
9159       if (arm_relobj->merge_flags_and_attributes())
9160         {
9161           this->merge_processor_specific_flags(
9162               arm_relobj->name(),
9163               arm_relobj->processor_specific_flags());
9164           this->merge_object_attributes(arm_relobj->name().c_str(),
9165                                         arm_relobj->attributes_section_data());
9166           merged_any_attributes = true;
9167         }
9168     }
9169
9170   for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
9171        p != input_objects->dynobj_end();
9172        ++p)
9173     {
9174       Arm_dynobj<big_endian>* arm_dynobj =
9175         Arm_dynobj<big_endian>::as_arm_dynobj(*p);
9176       this->merge_processor_specific_flags(
9177           arm_dynobj->name(),
9178           arm_dynobj->processor_specific_flags());
9179       this->merge_object_attributes(arm_dynobj->name().c_str(),
9180                                     arm_dynobj->attributes_section_data());
9181       merged_any_attributes = true;
9182     }
9183
9184   // Create an empty uninitialized attribute section if we still don't have it
9185   // at this moment.  This happens if there is no attributes sections in all
9186   // inputs.
9187   if (this->attributes_section_data_ == NULL)
9188     this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
9189
9190   const Object_attribute* cpu_arch_attr =
9191     this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
9192   // Check if we need to use Cortex-A8 workaround.
9193   if (parameters->options().user_set_fix_cortex_a8())
9194     this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
9195   else
9196     {
9197       // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
9198       // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
9199       // profile.
9200       const Object_attribute* cpu_arch_profile_attr =
9201         this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
9202       this->fix_cortex_a8_ =
9203         (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
9204          && (cpu_arch_profile_attr->int_value() == 'A'
9205              || cpu_arch_profile_attr->int_value() == 0));
9206     }
9207
9208   // Check if we can use V4BX interworking.
9209   // The V4BX interworking stub contains BX instruction,
9210   // which is not specified for some profiles.
9211   if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
9212       && !this->may_use_v4t_interworking())
9213     gold_error(_("unable to provide V4BX reloc interworking fix up; "
9214                  "the target profile does not support BX instruction"));
9215
9216   // Fill in some more dynamic tags.
9217   const Reloc_section* rel_plt = (this->plt_ == NULL
9218                                   ? NULL
9219                                   : this->plt_->rel_plt());
9220   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
9221                                   this->rel_dyn_, true, false);
9222
9223   // Emit any relocs we saved in an attempt to avoid generating COPY
9224   // relocs.
9225   if (this->copy_relocs_.any_saved_relocs())
9226     this->copy_relocs_.emit(this->rel_dyn_section(layout));
9227
9228   // Handle the .ARM.exidx section.
9229   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
9230
9231   if (!parameters->options().relocatable())
9232     {
9233       if (exidx_section != NULL
9234           && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
9235         {
9236           // For the ARM target, we need to add a PT_ARM_EXIDX segment for
9237           // the .ARM.exidx section.
9238           if (!layout->script_options()->saw_phdrs_clause())
9239             {
9240               gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
9241                                                       0)
9242                           == NULL);
9243               Output_segment*  exidx_segment =
9244                 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
9245               exidx_segment->add_output_section_to_nonload(exidx_section,
9246                                                            elfcpp::PF_R);
9247             }
9248         }
9249     }
9250
9251   // Create an .ARM.attributes section if we have merged any attributes
9252   // from inputs.
9253   if (merged_any_attributes)
9254     {
9255       Output_attributes_section_data* attributes_section =
9256       new Output_attributes_section_data(*this->attributes_section_data_);
9257       layout->add_output_section_data(".ARM.attributes",
9258                                       elfcpp::SHT_ARM_ATTRIBUTES, 0,
9259                                       attributes_section, ORDER_INVALID,
9260                                       false);
9261     }
9262
9263   // Fix up links in section EXIDX headers.
9264   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
9265        p != layout->section_list().end();
9266        ++p)
9267     if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
9268       {
9269         Arm_output_section<big_endian>* os =
9270           Arm_output_section<big_endian>::as_arm_output_section(*p);
9271         os->set_exidx_section_link();
9272       }
9273 }
9274
9275 // Return whether a direct absolute static relocation needs to be applied.
9276 // In cases where Scan::local() or Scan::global() has created
9277 // a dynamic relocation other than R_ARM_RELATIVE, the addend
9278 // of the relocation is carried in the data, and we must not
9279 // apply the static relocation.
9280
9281 template<bool big_endian>
9282 inline bool
9283 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
9284     const Sized_symbol<32>* gsym,
9285     unsigned int r_type,
9286     bool is_32bit,
9287     Output_section* output_section)
9288 {
9289   // If the output section is not allocated, then we didn't call
9290   // scan_relocs, we didn't create a dynamic reloc, and we must apply
9291   // the reloc here.
9292   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
9293       return true;
9294
9295   int ref_flags = Scan::get_reference_flags(r_type);
9296
9297   // For local symbols, we will have created a non-RELATIVE dynamic
9298   // relocation only if (a) the output is position independent,
9299   // (b) the relocation is absolute (not pc- or segment-relative), and
9300   // (c) the relocation is not 32 bits wide.
9301   if (gsym == NULL)
9302     return !(parameters->options().output_is_position_independent()
9303              && (ref_flags & Symbol::ABSOLUTE_REF)
9304              && !is_32bit);
9305
9306   // For global symbols, we use the same helper routines used in the
9307   // scan pass.  If we did not create a dynamic relocation, or if we
9308   // created a RELATIVE dynamic relocation, we should apply the static
9309   // relocation.
9310   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
9311   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
9312                  && gsym->can_use_relative_reloc(ref_flags
9313                                                  & Symbol::FUNCTION_CALL);
9314   return !has_dyn || is_rel;
9315 }
9316
9317 // Perform a relocation.
9318
9319 template<bool big_endian>
9320 inline bool
9321 Target_arm<big_endian>::Relocate::relocate(
9322     const Relocate_info<32, big_endian>* relinfo,
9323     Target_arm* target,
9324     Output_section* output_section,
9325     size_t relnum,
9326     const elfcpp::Rel<32, big_endian>& rel,
9327     unsigned int r_type,
9328     const Sized_symbol<32>* gsym,
9329     const Symbol_value<32>* psymval,
9330     unsigned char* view,
9331     Arm_address address,
9332     section_size_type view_size)
9333 {
9334   if (view == NULL)
9335     return true;
9336
9337   typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
9338
9339   r_type = get_real_reloc_type(r_type);
9340   const Arm_reloc_property* reloc_property =
9341     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9342   if (reloc_property == NULL)
9343     {
9344       std::string reloc_name =
9345         arm_reloc_property_table->reloc_name_in_error_message(r_type);
9346       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9347                              _("cannot relocate %s in object file"),
9348                              reloc_name.c_str());
9349       return true;
9350     }
9351
9352   const Arm_relobj<big_endian>* object =
9353     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9354
9355   // If the final branch target of a relocation is THUMB instruction, this
9356   // is 1.  Otherwise it is 0.
9357   Arm_address thumb_bit = 0;
9358   Symbol_value<32> symval;
9359   bool is_weakly_undefined_without_plt = false;
9360   bool have_got_offset = false;
9361   unsigned int got_offset = 0;
9362
9363   // If the relocation uses the GOT entry of a symbol instead of the symbol
9364   // itself, we don't care about whether the symbol is defined or what kind
9365   // of symbol it is.
9366   if (reloc_property->uses_got_entry())
9367     {
9368       // Get the GOT offset.
9369       // The GOT pointer points to the end of the GOT section.
9370       // We need to subtract the size of the GOT section to get
9371       // the actual offset to use in the relocation.
9372       // TODO: We should move GOT offset computing code in TLS relocations
9373       // to here.
9374       switch (r_type)
9375         {
9376         case elfcpp::R_ARM_GOT_BREL:
9377         case elfcpp::R_ARM_GOT_PREL:
9378           if (gsym != NULL)
9379             {
9380               gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
9381               got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
9382                             - target->got_size());
9383             }
9384           else
9385             {
9386               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9387               gold_assert(object->local_has_got_offset(r_sym,
9388                                                        GOT_TYPE_STANDARD));
9389               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
9390                             - target->got_size());
9391             }
9392           have_got_offset = true;
9393           break;
9394
9395         default:
9396           break;
9397         }
9398     }
9399   else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
9400     {
9401       if (gsym != NULL)
9402         {
9403           // This is a global symbol.  Determine if we use PLT and if the
9404           // final target is THUMB.
9405           if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
9406             {
9407               // This uses a PLT, change the symbol value.
9408               symval.set_output_value(target->plt_address_for_global(gsym));
9409               psymval = &symval;
9410             }
9411           else if (gsym->is_weak_undefined())
9412             {
9413               // This is a weakly undefined symbol and we do not use PLT
9414               // for this relocation.  A branch targeting this symbol will
9415               // be converted into an NOP.
9416               is_weakly_undefined_without_plt = true;
9417             }
9418           else if (gsym->is_undefined() && reloc_property->uses_symbol())
9419             {
9420               // This relocation uses the symbol value but the symbol is
9421               // undefined.  Exit early and have the caller reporting an
9422               // error.
9423               return true;
9424             }
9425           else
9426             {
9427               // Set thumb bit if symbol:
9428               // -Has type STT_ARM_TFUNC or
9429               // -Has type STT_FUNC, is defined and with LSB in value set.
9430               thumb_bit =
9431                 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
9432                  || (gsym->type() == elfcpp::STT_FUNC
9433                      && !gsym->is_undefined()
9434                      && ((psymval->value(object, 0) & 1) != 0)))
9435                 ? 1
9436                 : 0);
9437             }
9438         }
9439       else
9440         {
9441           // This is a local symbol.  Determine if the final target is THUMB.
9442           // We saved this information when all the local symbols were read.
9443           elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
9444           unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9445           thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9446
9447           if (psymval->is_ifunc_symbol() && object->local_has_plt_offset(r_sym))
9448             {
9449               symval.set_output_value(
9450                   target->plt_address_for_local(object, r_sym));
9451               psymval = &symval;
9452             }
9453         }
9454     }
9455   else
9456     {
9457       // This is a fake relocation synthesized for a stub.  It does not have
9458       // a real symbol.  We just look at the LSB of the symbol value to
9459       // determine if the target is THUMB or not.
9460       thumb_bit = ((psymval->value(object, 0) & 1) != 0);
9461     }
9462
9463   // Strip LSB if this points to a THUMB target.
9464   if (thumb_bit != 0
9465       && reloc_property->uses_thumb_bit()
9466       && ((psymval->value(object, 0) & 1) != 0))
9467     {
9468       Arm_address stripped_value =
9469         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9470       symval.set_output_value(stripped_value);
9471       psymval = &symval;
9472     }
9473
9474   // To look up relocation stubs, we need to pass the symbol table index of
9475   // a local symbol.
9476   unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9477
9478   // Get the addressing origin of the output segment defining the
9479   // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
9480   Arm_address sym_origin = 0;
9481   if (reloc_property->uses_symbol_base())
9482     {
9483       if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
9484         // R_ARM_BASE_ABS with the NULL symbol will give the
9485         // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
9486         // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
9487         sym_origin = target->got_plt_section()->address();
9488       else if (gsym == NULL)
9489         sym_origin = 0;
9490       else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
9491         sym_origin = gsym->output_segment()->vaddr();
9492       else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
9493         sym_origin = gsym->output_data()->address();
9494
9495       // TODO: Assumes the segment base to be zero for the global symbols
9496       // till the proper support for the segment-base-relative addressing
9497       // will be implemented.  This is consistent with GNU ld.
9498     }
9499
9500   // For relative addressing relocation, find out the relative address base.
9501   Arm_address relative_address_base = 0;
9502   switch(reloc_property->relative_address_base())
9503     {
9504     case Arm_reloc_property::RAB_NONE:
9505     // Relocations with relative address bases RAB_TLS and RAB_tp are
9506     // handled by relocate_tls.  So we do not need to do anything here.
9507     case Arm_reloc_property::RAB_TLS:
9508     case Arm_reloc_property::RAB_tp:
9509       break;
9510     case Arm_reloc_property::RAB_B_S:
9511       relative_address_base = sym_origin;
9512       break;
9513     case Arm_reloc_property::RAB_GOT_ORG:
9514       relative_address_base = target->got_plt_section()->address();
9515       break;
9516     case Arm_reloc_property::RAB_P:
9517       relative_address_base = address;
9518       break;
9519     case Arm_reloc_property::RAB_Pa:
9520       relative_address_base = address & 0xfffffffcU;
9521       break;
9522     default:
9523       gold_unreachable();
9524     }
9525
9526   typename Arm_relocate_functions::Status reloc_status =
9527         Arm_relocate_functions::STATUS_OKAY;
9528   bool check_overflow = reloc_property->checks_overflow();
9529   switch (r_type)
9530     {
9531     case elfcpp::R_ARM_NONE:
9532       break;
9533
9534     case elfcpp::R_ARM_ABS8:
9535       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9536         reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
9537       break;
9538
9539     case elfcpp::R_ARM_ABS12:
9540       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9541         reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
9542       break;
9543
9544     case elfcpp::R_ARM_ABS16:
9545       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9546         reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
9547       break;
9548
9549     case elfcpp::R_ARM_ABS32:
9550       if (should_apply_static_reloc(gsym, r_type, true, output_section))
9551         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9552                                                      thumb_bit);
9553       break;
9554
9555     case elfcpp::R_ARM_ABS32_NOI:
9556       if (should_apply_static_reloc(gsym, r_type, true, output_section))
9557         // No thumb bit for this relocation: (S + A)
9558         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9559                                                      0);
9560       break;
9561
9562     case elfcpp::R_ARM_MOVW_ABS_NC:
9563       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9564         reloc_status = Arm_relocate_functions::movw(view, object, psymval,
9565                                                     0, thumb_bit,
9566                                                     check_overflow);
9567       break;
9568
9569     case elfcpp::R_ARM_MOVT_ABS:
9570       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9571         reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
9572       break;
9573
9574     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9575       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9576         reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
9577                                                         0, thumb_bit, false);
9578       break;
9579
9580     case elfcpp::R_ARM_THM_MOVT_ABS:
9581       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9582         reloc_status = Arm_relocate_functions::thm_movt(view, object,
9583                                                         psymval, 0);
9584       break;
9585
9586     case elfcpp::R_ARM_MOVW_PREL_NC:
9587     case elfcpp::R_ARM_MOVW_BREL_NC:
9588     case elfcpp::R_ARM_MOVW_BREL:
9589       reloc_status =
9590         Arm_relocate_functions::movw(view, object, psymval,
9591                                      relative_address_base, thumb_bit,
9592                                      check_overflow);
9593       break;
9594
9595     case elfcpp::R_ARM_MOVT_PREL:
9596     case elfcpp::R_ARM_MOVT_BREL:
9597       reloc_status =
9598         Arm_relocate_functions::movt(view, object, psymval,
9599                                      relative_address_base);
9600       break;
9601
9602     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9603     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9604     case elfcpp::R_ARM_THM_MOVW_BREL:
9605       reloc_status =
9606         Arm_relocate_functions::thm_movw(view, object, psymval,
9607                                          relative_address_base,
9608                                          thumb_bit, check_overflow);
9609       break;
9610
9611     case elfcpp::R_ARM_THM_MOVT_PREL:
9612     case elfcpp::R_ARM_THM_MOVT_BREL:
9613       reloc_status =
9614         Arm_relocate_functions::thm_movt(view, object, psymval,
9615                                          relative_address_base);
9616       break;
9617
9618     case elfcpp::R_ARM_REL32:
9619       reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9620                                                    address, thumb_bit);
9621       break;
9622
9623     case elfcpp::R_ARM_THM_ABS5:
9624       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9625         reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
9626       break;
9627
9628     // Thumb long branches.
9629     case elfcpp::R_ARM_THM_CALL:
9630     case elfcpp::R_ARM_THM_XPC22:
9631     case elfcpp::R_ARM_THM_JUMP24:
9632       reloc_status =
9633         Arm_relocate_functions::thumb_branch_common(
9634             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9635             thumb_bit, is_weakly_undefined_without_plt);
9636       break;
9637
9638     case elfcpp::R_ARM_GOTOFF32:
9639       {
9640         Arm_address got_origin;
9641         got_origin = target->got_plt_section()->address();
9642         reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9643                                                      got_origin, thumb_bit);
9644       }
9645       break;
9646
9647     case elfcpp::R_ARM_BASE_PREL:
9648       gold_assert(gsym != NULL);
9649       reloc_status =
9650           Arm_relocate_functions::base_prel(view, sym_origin, address);
9651       break;
9652
9653     case elfcpp::R_ARM_BASE_ABS:
9654       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9655         reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
9656       break;
9657
9658     case elfcpp::R_ARM_GOT_BREL:
9659       gold_assert(have_got_offset);
9660       reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
9661       break;
9662
9663     case elfcpp::R_ARM_GOT_PREL:
9664       gold_assert(have_got_offset);
9665       // Get the address origin for GOT PLT, which is allocated right
9666       // after the GOT section, to calculate an absolute address of
9667       // the symbol GOT entry (got_origin + got_offset).
9668       Arm_address got_origin;
9669       got_origin = target->got_plt_section()->address();
9670       reloc_status = Arm_relocate_functions::got_prel(view,
9671                                                       got_origin + got_offset,
9672                                                       address);
9673       break;
9674
9675     case elfcpp::R_ARM_PLT32:
9676     case elfcpp::R_ARM_CALL:
9677     case elfcpp::R_ARM_JUMP24:
9678     case elfcpp::R_ARM_XPC25:
9679       gold_assert(gsym == NULL
9680                   || gsym->has_plt_offset()
9681                   || gsym->final_value_is_known()
9682                   || (gsym->is_defined()
9683                       && !gsym->is_from_dynobj()
9684                       && !gsym->is_preemptible()));
9685       reloc_status =
9686         Arm_relocate_functions::arm_branch_common(
9687             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9688             thumb_bit, is_weakly_undefined_without_plt);
9689       break;
9690
9691     case elfcpp::R_ARM_THM_JUMP19:
9692       reloc_status =
9693         Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9694                                            thumb_bit);
9695       break;
9696
9697     case elfcpp::R_ARM_THM_JUMP6:
9698       reloc_status =
9699         Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9700       break;
9701
9702     case elfcpp::R_ARM_THM_JUMP8:
9703       reloc_status =
9704         Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9705       break;
9706
9707     case elfcpp::R_ARM_THM_JUMP11:
9708       reloc_status =
9709         Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9710       break;
9711
9712     case elfcpp::R_ARM_PREL31:
9713       reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9714                                                     address, thumb_bit);
9715       break;
9716
9717     case elfcpp::R_ARM_V4BX:
9718       if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9719         {
9720           const bool is_v4bx_interworking =
9721               (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9722           reloc_status =
9723             Arm_relocate_functions::v4bx(relinfo, view, object, address,
9724                                          is_v4bx_interworking);
9725         }
9726       break;
9727
9728     case elfcpp::R_ARM_THM_PC8:
9729       reloc_status =
9730         Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9731       break;
9732
9733     case elfcpp::R_ARM_THM_PC12:
9734       reloc_status =
9735         Arm_relocate_functions::thm_pc12(view, object, psymval, address);
9736       break;
9737
9738     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9739       reloc_status =
9740         Arm_relocate_functions::thm_alu11(view, object, psymval, address,
9741                                           thumb_bit);
9742       break;
9743
9744     case elfcpp::R_ARM_ALU_PC_G0_NC:
9745     case elfcpp::R_ARM_ALU_PC_G0:
9746     case elfcpp::R_ARM_ALU_PC_G1_NC:
9747     case elfcpp::R_ARM_ALU_PC_G1:
9748     case elfcpp::R_ARM_ALU_PC_G2:
9749     case elfcpp::R_ARM_ALU_SB_G0_NC:
9750     case elfcpp::R_ARM_ALU_SB_G0:
9751     case elfcpp::R_ARM_ALU_SB_G1_NC:
9752     case elfcpp::R_ARM_ALU_SB_G1:
9753     case elfcpp::R_ARM_ALU_SB_G2:
9754       reloc_status =
9755         Arm_relocate_functions::arm_grp_alu(view, object, psymval,
9756                                             reloc_property->group_index(),
9757                                             relative_address_base,
9758                                             thumb_bit, check_overflow);
9759       break;
9760
9761     case elfcpp::R_ARM_LDR_PC_G0:
9762     case elfcpp::R_ARM_LDR_PC_G1:
9763     case elfcpp::R_ARM_LDR_PC_G2:
9764     case elfcpp::R_ARM_LDR_SB_G0:
9765     case elfcpp::R_ARM_LDR_SB_G1:
9766     case elfcpp::R_ARM_LDR_SB_G2:
9767       reloc_status =
9768           Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9769                                               reloc_property->group_index(),
9770                                               relative_address_base);
9771       break;
9772
9773     case elfcpp::R_ARM_LDRS_PC_G0:
9774     case elfcpp::R_ARM_LDRS_PC_G1:
9775     case elfcpp::R_ARM_LDRS_PC_G2:
9776     case elfcpp::R_ARM_LDRS_SB_G0:
9777     case elfcpp::R_ARM_LDRS_SB_G1:
9778     case elfcpp::R_ARM_LDRS_SB_G2:
9779       reloc_status =
9780           Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9781                                                reloc_property->group_index(),
9782                                                relative_address_base);
9783       break;
9784
9785     case elfcpp::R_ARM_LDC_PC_G0:
9786     case elfcpp::R_ARM_LDC_PC_G1:
9787     case elfcpp::R_ARM_LDC_PC_G2:
9788     case elfcpp::R_ARM_LDC_SB_G0:
9789     case elfcpp::R_ARM_LDC_SB_G1:
9790     case elfcpp::R_ARM_LDC_SB_G2:
9791       reloc_status =
9792           Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9793                                               reloc_property->group_index(),
9794                                               relative_address_base);
9795       break;
9796
9797       // These are initial tls relocs, which are expected when
9798       // linking.
9799     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9800     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9801     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9802     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9803     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9804       reloc_status =
9805         this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9806                            view, address, view_size);
9807       break;
9808
9809     // The known and unknown unsupported and/or deprecated relocations.
9810     case elfcpp::R_ARM_PC24:
9811     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9812     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9813     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9814     default:
9815       // Just silently leave the method. We should get an appropriate error
9816       // message in the scan methods.
9817       break;
9818     }
9819
9820   // Report any errors.
9821   switch (reloc_status)
9822     {
9823     case Arm_relocate_functions::STATUS_OKAY:
9824       break;
9825     case Arm_relocate_functions::STATUS_OVERFLOW:
9826       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9827                              _("relocation overflow in %s"),
9828                              reloc_property->name().c_str());
9829       break;
9830     case Arm_relocate_functions::STATUS_BAD_RELOC:
9831       gold_error_at_location(
9832         relinfo,
9833         relnum,
9834         rel.get_r_offset(),
9835         _("unexpected opcode while processing relocation %s"),
9836         reloc_property->name().c_str());
9837       break;
9838     default:
9839       gold_unreachable();
9840     }
9841
9842   return true;
9843 }
9844
9845 // Perform a TLS relocation.
9846
9847 template<bool big_endian>
9848 inline typename Arm_relocate_functions<big_endian>::Status
9849 Target_arm<big_endian>::Relocate::relocate_tls(
9850     const Relocate_info<32, big_endian>* relinfo,
9851     Target_arm<big_endian>* target,
9852     size_t relnum,
9853     const elfcpp::Rel<32, big_endian>& rel,
9854     unsigned int r_type,
9855     const Sized_symbol<32>* gsym,
9856     const Symbol_value<32>* psymval,
9857     unsigned char* view,
9858     elfcpp::Elf_types<32>::Elf_Addr address,
9859     section_size_type /*view_size*/ )
9860 {
9861   typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9862   typedef Relocate_functions<32, big_endian> RelocFuncs;
9863   Output_segment* tls_segment = relinfo->layout->tls_segment();
9864
9865   const Sized_relobj_file<32, big_endian>* object = relinfo->object;
9866
9867   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9868
9869   const bool is_final = (gsym == NULL
9870                          ? !parameters->options().shared()
9871                          : gsym->final_value_is_known());
9872   const tls::Tls_optimization optimized_type
9873       = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9874   switch (r_type)
9875     {
9876     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9877         {
9878           unsigned int got_type = GOT_TYPE_TLS_PAIR;
9879           unsigned int got_offset;
9880           if (gsym != NULL)
9881             {
9882               gold_assert(gsym->has_got_offset(got_type));
9883               got_offset = gsym->got_offset(got_type) - target->got_size();
9884             }
9885           else
9886             {
9887               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9888               gold_assert(object->local_has_got_offset(r_sym, got_type));
9889               got_offset = (object->local_got_offset(r_sym, got_type)
9890                             - target->got_size());
9891             }
9892           if (optimized_type == tls::TLSOPT_NONE)
9893             {
9894               Arm_address got_entry =
9895                 target->got_plt_section()->address() + got_offset;
9896
9897               // Relocate the field with the PC relative offset of the pair of
9898               // GOT entries.
9899               RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9900               return ArmRelocFuncs::STATUS_OKAY;
9901             }
9902         }
9903       break;
9904
9905     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9906       if (optimized_type == tls::TLSOPT_NONE)
9907         {
9908           // Relocate the field with the offset of the GOT entry for
9909           // the module index.
9910           unsigned int got_offset;
9911           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9912                         - target->got_size());
9913           Arm_address got_entry =
9914             target->got_plt_section()->address() + got_offset;
9915
9916           // Relocate the field with the PC relative offset of the pair of
9917           // GOT entries.
9918           RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9919           return ArmRelocFuncs::STATUS_OKAY;
9920         }
9921       break;
9922
9923     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9924       RelocFuncs::rel32_unaligned(view, value);
9925       return ArmRelocFuncs::STATUS_OKAY;
9926
9927     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9928       if (optimized_type == tls::TLSOPT_NONE)
9929         {
9930           // Relocate the field with the offset of the GOT entry for
9931           // the tp-relative offset of the symbol.
9932           unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9933           unsigned int got_offset;
9934           if (gsym != NULL)
9935             {
9936               gold_assert(gsym->has_got_offset(got_type));
9937               got_offset = gsym->got_offset(got_type);
9938             }
9939           else
9940             {
9941               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9942               gold_assert(object->local_has_got_offset(r_sym, got_type));
9943               got_offset = object->local_got_offset(r_sym, got_type);
9944             }
9945
9946           // All GOT offsets are relative to the end of the GOT.
9947           got_offset -= target->got_size();
9948
9949           Arm_address got_entry =
9950             target->got_plt_section()->address() + got_offset;
9951
9952           // Relocate the field with the PC relative offset of the GOT entry.
9953           RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9954           return ArmRelocFuncs::STATUS_OKAY;
9955         }
9956       break;
9957
9958     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9959       // If we're creating a shared library, a dynamic relocation will
9960       // have been created for this location, so do not apply it now.
9961       if (!parameters->options().shared())
9962         {
9963           gold_assert(tls_segment != NULL);
9964
9965           // $tp points to the TCB, which is followed by the TLS, so we
9966           // need to add TCB size to the offset.
9967           Arm_address aligned_tcb_size =
9968             align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9969           RelocFuncs::rel32_unaligned(view, value + aligned_tcb_size);
9970
9971         }
9972       return ArmRelocFuncs::STATUS_OKAY;
9973
9974     default:
9975       gold_unreachable();
9976     }
9977
9978   gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9979                          _("unsupported reloc %u"),
9980                          r_type);
9981   return ArmRelocFuncs::STATUS_BAD_RELOC;
9982 }
9983
9984 // Relocate section data.
9985
9986 template<bool big_endian>
9987 void
9988 Target_arm<big_endian>::relocate_section(
9989     const Relocate_info<32, big_endian>* relinfo,
9990     unsigned int sh_type,
9991     const unsigned char* prelocs,
9992     size_t reloc_count,
9993     Output_section* output_section,
9994     bool needs_special_offset_handling,
9995     unsigned char* view,
9996     Arm_address address,
9997     section_size_type view_size,
9998     const Reloc_symbol_changes* reloc_symbol_changes)
9999 {
10000   typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
10001   gold_assert(sh_type == elfcpp::SHT_REL);
10002
10003   // See if we are relocating a relaxed input section.  If so, the view
10004   // covers the whole output section and we need to adjust accordingly.
10005   if (needs_special_offset_handling)
10006     {
10007       const Output_relaxed_input_section* poris =
10008         output_section->find_relaxed_input_section(relinfo->object,
10009                                                    relinfo->data_shndx);
10010       if (poris != NULL)
10011         {
10012           Arm_address section_address = poris->address();
10013           section_size_type section_size = poris->data_size();
10014
10015           gold_assert((section_address >= address)
10016                       && ((section_address + section_size)
10017                           <= (address + view_size)));
10018
10019           off_t offset = section_address - address;
10020           view += offset;
10021           address += offset;
10022           view_size = section_size;
10023         }
10024     }
10025
10026   gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
10027                          Arm_relocate, gold::Default_comdat_behavior>(
10028     relinfo,
10029     this,
10030     prelocs,
10031     reloc_count,
10032     output_section,
10033     needs_special_offset_handling,
10034     view,
10035     address,
10036     view_size,
10037     reloc_symbol_changes);
10038 }
10039
10040 // Return the size of a relocation while scanning during a relocatable
10041 // link.
10042
10043 template<bool big_endian>
10044 unsigned int
10045 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
10046     unsigned int r_type,
10047     Relobj* object)
10048 {
10049   r_type = get_real_reloc_type(r_type);
10050   const Arm_reloc_property* arp =
10051       arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10052   if (arp != NULL)
10053     return arp->size();
10054   else
10055     {
10056       std::string reloc_name =
10057         arm_reloc_property_table->reloc_name_in_error_message(r_type);
10058       gold_error(_("%s: unexpected %s in object file"),
10059                  object->name().c_str(), reloc_name.c_str());
10060       return 0;
10061     }
10062 }
10063
10064 // Scan the relocs during a relocatable link.
10065
10066 template<bool big_endian>
10067 void
10068 Target_arm<big_endian>::scan_relocatable_relocs(
10069     Symbol_table* symtab,
10070     Layout* layout,
10071     Sized_relobj_file<32, big_endian>* object,
10072     unsigned int data_shndx,
10073     unsigned int sh_type,
10074     const unsigned char* prelocs,
10075     size_t reloc_count,
10076     Output_section* output_section,
10077     bool needs_special_offset_handling,
10078     size_t local_symbol_count,
10079     const unsigned char* plocal_symbols,
10080     Relocatable_relocs* rr)
10081 {
10082   gold_assert(sh_type == elfcpp::SHT_REL);
10083
10084   typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
10085     Relocatable_size_for_reloc> Scan_relocatable_relocs;
10086
10087   gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
10088       Scan_relocatable_relocs>(
10089     symtab,
10090     layout,
10091     object,
10092     data_shndx,
10093     prelocs,
10094     reloc_count,
10095     output_section,
10096     needs_special_offset_handling,
10097     local_symbol_count,
10098     plocal_symbols,
10099     rr);
10100 }
10101
10102 // Emit relocations for a section.
10103
10104 template<bool big_endian>
10105 void
10106 Target_arm<big_endian>::relocate_relocs(
10107     const Relocate_info<32, big_endian>* relinfo,
10108     unsigned int sh_type,
10109     const unsigned char* prelocs,
10110     size_t reloc_count,
10111     Output_section* output_section,
10112     typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
10113     const Relocatable_relocs* rr,
10114     unsigned char* view,
10115     Arm_address view_address,
10116     section_size_type view_size,
10117     unsigned char* reloc_view,
10118     section_size_type reloc_view_size)
10119 {
10120   gold_assert(sh_type == elfcpp::SHT_REL);
10121
10122   gold::relocate_relocs<32, big_endian, elfcpp::SHT_REL>(
10123     relinfo,
10124     prelocs,
10125     reloc_count,
10126     output_section,
10127     offset_in_output_section,
10128     rr,
10129     view,
10130     view_address,
10131     view_size,
10132     reloc_view,
10133     reloc_view_size);
10134 }
10135
10136 // Perform target-specific processing in a relocatable link.  This is
10137 // only used if we use the relocation strategy RELOC_SPECIAL.
10138
10139 template<bool big_endian>
10140 void
10141 Target_arm<big_endian>::relocate_special_relocatable(
10142     const Relocate_info<32, big_endian>* relinfo,
10143     unsigned int sh_type,
10144     const unsigned char* preloc_in,
10145     size_t relnum,
10146     Output_section* output_section,
10147     typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
10148     unsigned char* view,
10149     elfcpp::Elf_types<32>::Elf_Addr view_address,
10150     section_size_type,
10151     unsigned char* preloc_out)
10152 {
10153   // We can only handle REL type relocation sections.
10154   gold_assert(sh_type == elfcpp::SHT_REL);
10155
10156   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
10157   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
10158     Reltype_write;
10159   const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
10160
10161   const Arm_relobj<big_endian>* object =
10162     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10163   const unsigned int local_count = object->local_symbol_count();
10164
10165   Reltype reloc(preloc_in);
10166   Reltype_write reloc_write(preloc_out);
10167
10168   elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
10169   const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
10170   const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
10171
10172   const Arm_reloc_property* arp =
10173     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10174   gold_assert(arp != NULL);
10175
10176   // Get the new symbol index.
10177   // We only use RELOC_SPECIAL strategy in local relocations.
10178   gold_assert(r_sym < local_count);
10179
10180   // We are adjusting a section symbol.  We need to find
10181   // the symbol table index of the section symbol for
10182   // the output section corresponding to input section
10183   // in which this symbol is defined.
10184   bool is_ordinary;
10185   unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
10186   gold_assert(is_ordinary);
10187   Output_section* os = object->output_section(shndx);
10188   gold_assert(os != NULL);
10189   gold_assert(os->needs_symtab_index());
10190   unsigned int new_symndx = os->symtab_index();
10191
10192   // Get the new offset--the location in the output section where
10193   // this relocation should be applied.
10194
10195   Arm_address offset = reloc.get_r_offset();
10196   Arm_address new_offset;
10197   if (offset_in_output_section != invalid_address)
10198     new_offset = offset + offset_in_output_section;
10199   else
10200     {
10201       section_offset_type sot_offset =
10202           convert_types<section_offset_type, Arm_address>(offset);
10203       section_offset_type new_sot_offset =
10204           output_section->output_offset(object, relinfo->data_shndx,
10205                                         sot_offset);
10206       gold_assert(new_sot_offset != -1);
10207       new_offset = new_sot_offset;
10208     }
10209
10210   // In an object file, r_offset is an offset within the section.
10211   // In an executable or dynamic object, generated by
10212   // --emit-relocs, r_offset is an absolute address.
10213   if (!parameters->options().relocatable())
10214     {
10215       new_offset += view_address;
10216       if (offset_in_output_section != invalid_address)
10217         new_offset -= offset_in_output_section;
10218     }
10219
10220   reloc_write.put_r_offset(new_offset);
10221   reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
10222
10223   // Handle the reloc addend.
10224   // The relocation uses a section symbol in the input file.
10225   // We are adjusting it to use a section symbol in the output
10226   // file.  The input section symbol refers to some address in
10227   // the input section.  We need the relocation in the output
10228   // file to refer to that same address.  This adjustment to
10229   // the addend is the same calculation we use for a simple
10230   // absolute relocation for the input section symbol.
10231
10232   const Symbol_value<32>* psymval = object->local_symbol(r_sym);
10233
10234   // Handle THUMB bit.
10235   Symbol_value<32> symval;
10236   Arm_address thumb_bit =
10237      object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
10238   if (thumb_bit != 0
10239       && arp->uses_thumb_bit()
10240       && ((psymval->value(object, 0) & 1) != 0))
10241     {
10242       Arm_address stripped_value =
10243         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
10244       symval.set_output_value(stripped_value);
10245       psymval = &symval;
10246     }
10247
10248   unsigned char* paddend = view + offset;
10249   typename Arm_relocate_functions<big_endian>::Status reloc_status =
10250         Arm_relocate_functions<big_endian>::STATUS_OKAY;
10251   switch (r_type)
10252     {
10253     case elfcpp::R_ARM_ABS8:
10254       reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
10255                                                               psymval);
10256       break;
10257
10258     case elfcpp::R_ARM_ABS12:
10259       reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
10260                                                                psymval);
10261       break;
10262
10263     case elfcpp::R_ARM_ABS16:
10264       reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
10265                                                                psymval);
10266       break;
10267
10268     case elfcpp::R_ARM_THM_ABS5:
10269       reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
10270                                                                   object,
10271                                                                   psymval);
10272       break;
10273
10274     case elfcpp::R_ARM_MOVW_ABS_NC:
10275     case elfcpp::R_ARM_MOVW_PREL_NC:
10276     case elfcpp::R_ARM_MOVW_BREL_NC:
10277     case elfcpp::R_ARM_MOVW_BREL:
10278       reloc_status = Arm_relocate_functions<big_endian>::movw(
10279           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
10280       break;
10281
10282     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
10283     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
10284     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
10285     case elfcpp::R_ARM_THM_MOVW_BREL:
10286       reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
10287           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
10288       break;
10289
10290     case elfcpp::R_ARM_THM_CALL:
10291     case elfcpp::R_ARM_THM_XPC22:
10292     case elfcpp::R_ARM_THM_JUMP24:
10293       reloc_status =
10294         Arm_relocate_functions<big_endian>::thumb_branch_common(
10295             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
10296             false);
10297       break;
10298
10299     case elfcpp::R_ARM_PLT32:
10300     case elfcpp::R_ARM_CALL:
10301     case elfcpp::R_ARM_JUMP24:
10302     case elfcpp::R_ARM_XPC25:
10303       reloc_status =
10304         Arm_relocate_functions<big_endian>::arm_branch_common(
10305             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
10306             false);
10307       break;
10308
10309     case elfcpp::R_ARM_THM_JUMP19:
10310       reloc_status =
10311         Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
10312                                                        psymval, 0, thumb_bit);
10313       break;
10314
10315     case elfcpp::R_ARM_THM_JUMP6:
10316       reloc_status =
10317         Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
10318                                                       0);
10319       break;
10320
10321     case elfcpp::R_ARM_THM_JUMP8:
10322       reloc_status =
10323         Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
10324                                                       0);
10325       break;
10326
10327     case elfcpp::R_ARM_THM_JUMP11:
10328       reloc_status =
10329         Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
10330                                                        0);
10331       break;
10332
10333     case elfcpp::R_ARM_PREL31:
10334       reloc_status =
10335         Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
10336                                                    thumb_bit);
10337       break;
10338
10339     case elfcpp::R_ARM_THM_PC8:
10340       reloc_status =
10341         Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
10342                                                     0);
10343       break;
10344
10345     case elfcpp::R_ARM_THM_PC12:
10346       reloc_status =
10347         Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
10348                                                      0);
10349       break;
10350
10351     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
10352       reloc_status =
10353         Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
10354                                                       0, thumb_bit);
10355       break;
10356
10357     // These relocation truncate relocation results so we cannot handle them
10358     // in a relocatable link.
10359     case elfcpp::R_ARM_MOVT_ABS:
10360     case elfcpp::R_ARM_THM_MOVT_ABS:
10361     case elfcpp::R_ARM_MOVT_PREL:
10362     case elfcpp::R_ARM_MOVT_BREL:
10363     case elfcpp::R_ARM_THM_MOVT_PREL:
10364     case elfcpp::R_ARM_THM_MOVT_BREL:
10365     case elfcpp::R_ARM_ALU_PC_G0_NC:
10366     case elfcpp::R_ARM_ALU_PC_G0:
10367     case elfcpp::R_ARM_ALU_PC_G1_NC:
10368     case elfcpp::R_ARM_ALU_PC_G1:
10369     case elfcpp::R_ARM_ALU_PC_G2:
10370     case elfcpp::R_ARM_ALU_SB_G0_NC:
10371     case elfcpp::R_ARM_ALU_SB_G0:
10372     case elfcpp::R_ARM_ALU_SB_G1_NC:
10373     case elfcpp::R_ARM_ALU_SB_G1:
10374     case elfcpp::R_ARM_ALU_SB_G2:
10375     case elfcpp::R_ARM_LDR_PC_G0:
10376     case elfcpp::R_ARM_LDR_PC_G1:
10377     case elfcpp::R_ARM_LDR_PC_G2:
10378     case elfcpp::R_ARM_LDR_SB_G0:
10379     case elfcpp::R_ARM_LDR_SB_G1:
10380     case elfcpp::R_ARM_LDR_SB_G2:
10381     case elfcpp::R_ARM_LDRS_PC_G0:
10382     case elfcpp::R_ARM_LDRS_PC_G1:
10383     case elfcpp::R_ARM_LDRS_PC_G2:
10384     case elfcpp::R_ARM_LDRS_SB_G0:
10385     case elfcpp::R_ARM_LDRS_SB_G1:
10386     case elfcpp::R_ARM_LDRS_SB_G2:
10387     case elfcpp::R_ARM_LDC_PC_G0:
10388     case elfcpp::R_ARM_LDC_PC_G1:
10389     case elfcpp::R_ARM_LDC_PC_G2:
10390     case elfcpp::R_ARM_LDC_SB_G0:
10391     case elfcpp::R_ARM_LDC_SB_G1:
10392     case elfcpp::R_ARM_LDC_SB_G2:
10393       gold_error(_("cannot handle %s in a relocatable link"),
10394                  arp->name().c_str());
10395       break;
10396
10397     default:
10398       gold_unreachable();
10399     }
10400
10401   // Report any errors.
10402   switch (reloc_status)
10403     {
10404     case Arm_relocate_functions<big_endian>::STATUS_OKAY:
10405       break;
10406     case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
10407       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
10408                              _("relocation overflow in %s"),
10409                              arp->name().c_str());
10410       break;
10411     case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
10412       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
10413         _("unexpected opcode while processing relocation %s"),
10414         arp->name().c_str());
10415       break;
10416     default:
10417       gold_unreachable();
10418     }
10419 }
10420
10421 // Return the value to use for a dynamic symbol which requires special
10422 // treatment.  This is how we support equality comparisons of function
10423 // pointers across shared library boundaries, as described in the
10424 // processor specific ABI supplement.
10425
10426 template<bool big_endian>
10427 uint64_t
10428 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
10429 {
10430   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
10431   return this->plt_address_for_global(gsym);
10432 }
10433
10434 // Map platform-specific relocs to real relocs
10435 //
10436 template<bool big_endian>
10437 unsigned int
10438 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
10439 {
10440   switch (r_type)
10441     {
10442     case elfcpp::R_ARM_TARGET1:
10443       // This is either R_ARM_ABS32 or R_ARM_REL32;
10444       return elfcpp::R_ARM_ABS32;
10445
10446     case elfcpp::R_ARM_TARGET2:
10447       // This can be any reloc type but usually is R_ARM_GOT_PREL
10448       return elfcpp::R_ARM_GOT_PREL;
10449
10450     default:
10451       return r_type;
10452     }
10453 }
10454
10455 // Whether if two EABI versions V1 and V2 are compatible.
10456
10457 template<bool big_endian>
10458 bool
10459 Target_arm<big_endian>::are_eabi_versions_compatible(
10460     elfcpp::Elf_Word v1,
10461     elfcpp::Elf_Word v2)
10462 {
10463   // v4 and v5 are the same spec before and after it was released,
10464   // so allow mixing them.
10465   if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
10466       || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
10467       || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
10468     return true;
10469
10470   return v1 == v2;
10471 }
10472
10473 // Combine FLAGS from an input object called NAME and the processor-specific
10474 // flags in the ELF header of the output.  Much of this is adapted from the
10475 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
10476 // in bfd/elf32-arm.c.
10477
10478 template<bool big_endian>
10479 void
10480 Target_arm<big_endian>::merge_processor_specific_flags(
10481     const std::string& name,
10482     elfcpp::Elf_Word flags)
10483 {
10484   if (this->are_processor_specific_flags_set())
10485     {
10486       elfcpp::Elf_Word out_flags = this->processor_specific_flags();
10487
10488       // Nothing to merge if flags equal to those in output.
10489       if (flags == out_flags)
10490         return;
10491
10492       // Complain about various flag mismatches.
10493       elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
10494       elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
10495       if (!this->are_eabi_versions_compatible(version1, version2)
10496           && parameters->options().warn_mismatch())
10497         gold_error(_("Source object %s has EABI version %d but output has "
10498                      "EABI version %d."),
10499                    name.c_str(),
10500                    (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
10501                    (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
10502     }
10503   else
10504     {
10505       // If the input is the default architecture and had the default
10506       // flags then do not bother setting the flags for the output
10507       // architecture, instead allow future merges to do this.  If no
10508       // future merges ever set these flags then they will retain their
10509       // uninitialised values, which surprise surprise, correspond
10510       // to the default values.
10511       if (flags == 0)
10512         return;
10513
10514       // This is the first time, just copy the flags.
10515       // We only copy the EABI version for now.
10516       this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
10517     }
10518 }
10519
10520 // Adjust ELF file header.
10521 template<bool big_endian>
10522 void
10523 Target_arm<big_endian>::do_adjust_elf_header(
10524     unsigned char* view,
10525     int len)
10526 {
10527   gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
10528
10529   elfcpp::Ehdr<32, big_endian> ehdr(view);
10530   elfcpp::Elf_Word flags = this->processor_specific_flags();
10531   unsigned char e_ident[elfcpp::EI_NIDENT];
10532   memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
10533
10534   if (elfcpp::arm_eabi_version(flags)
10535       == elfcpp::EF_ARM_EABI_UNKNOWN)
10536     e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
10537   else
10538     e_ident[elfcpp::EI_OSABI] = 0;
10539   e_ident[elfcpp::EI_ABIVERSION] = 0;
10540
10541   // FIXME: Do EF_ARM_BE8 adjustment.
10542
10543   // If we're working in EABI_VER5, set the hard/soft float ABI flags
10544   // as appropriate.
10545   if (elfcpp::arm_eabi_version(flags) == elfcpp::EF_ARM_EABI_VER5)
10546   {
10547     elfcpp::Elf_Half type = ehdr.get_e_type();
10548     if (type == elfcpp::ET_EXEC || type == elfcpp::ET_DYN)
10549       {
10550         Object_attribute* attr = this->get_aeabi_object_attribute(elfcpp::Tag_ABI_VFP_args);
10551         if (attr->int_value() == elfcpp::AEABI_VFP_args_vfp)
10552           flags |= elfcpp::EF_ARM_ABI_FLOAT_HARD;
10553         else
10554           flags |= elfcpp::EF_ARM_ABI_FLOAT_SOFT;
10555         this->set_processor_specific_flags(flags);
10556       }
10557   }
10558   elfcpp::Ehdr_write<32, big_endian> oehdr(view);
10559   oehdr.put_e_ident(e_ident);
10560   oehdr.put_e_flags(this->processor_specific_flags());
10561 }
10562
10563 // do_make_elf_object to override the same function in the base class.
10564 // We need to use a target-specific sub-class of
10565 // Sized_relobj_file<32, big_endian> to store ARM specific information.
10566 // Hence we need to have our own ELF object creation.
10567
10568 template<bool big_endian>
10569 Object*
10570 Target_arm<big_endian>::do_make_elf_object(
10571     const std::string& name,
10572     Input_file* input_file,
10573     off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
10574 {
10575   int et = ehdr.get_e_type();
10576   // ET_EXEC files are valid input for --just-symbols/-R,
10577   // and we treat them as relocatable objects.
10578   if (et == elfcpp::ET_REL
10579       || (et == elfcpp::ET_EXEC && input_file->just_symbols()))
10580     {
10581       Arm_relobj<big_endian>* obj =
10582         new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
10583       obj->setup();
10584       return obj;
10585     }
10586   else if (et == elfcpp::ET_DYN)
10587     {
10588       Sized_dynobj<32, big_endian>* obj =
10589         new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
10590       obj->setup();
10591       return obj;
10592     }
10593   else
10594     {
10595       gold_error(_("%s: unsupported ELF file type %d"),
10596                  name.c_str(), et);
10597       return NULL;
10598     }
10599 }
10600
10601 // Read the architecture from the Tag_also_compatible_with attribute, if any.
10602 // Returns -1 if no architecture could be read.
10603 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
10604
10605 template<bool big_endian>
10606 int
10607 Target_arm<big_endian>::get_secondary_compatible_arch(
10608     const Attributes_section_data* pasd)
10609 {
10610   const Object_attribute* known_attributes =
10611     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10612
10613   // Note: the tag and its argument below are uleb128 values, though
10614   // currently-defined values fit in one byte for each.
10615   const std::string& sv =
10616     known_attributes[elfcpp::Tag_also_compatible_with].string_value();
10617   if (sv.size() == 2
10618       && sv.data()[0] == elfcpp::Tag_CPU_arch
10619       && (sv.data()[1] & 128) != 128)
10620    return sv.data()[1];
10621
10622   // This tag is "safely ignorable", so don't complain if it looks funny.
10623   return -1;
10624 }
10625
10626 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10627 // The tag is removed if ARCH is -1.
10628 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10629
10630 template<bool big_endian>
10631 void
10632 Target_arm<big_endian>::set_secondary_compatible_arch(
10633     Attributes_section_data* pasd,
10634     int arch)
10635 {
10636   Object_attribute* known_attributes =
10637     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10638
10639   if (arch == -1)
10640     {
10641       known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10642       return;
10643     }
10644
10645   // Note: the tag and its argument below are uleb128 values, though
10646   // currently-defined values fit in one byte for each.
10647   char sv[3];
10648   sv[0] = elfcpp::Tag_CPU_arch;
10649   gold_assert(arch != 0);
10650   sv[1] = arch;
10651   sv[2] = '\0';
10652
10653   known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10654 }
10655
10656 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10657 // into account.
10658 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10659
10660 template<bool big_endian>
10661 int
10662 Target_arm<big_endian>::tag_cpu_arch_combine(
10663     const char* name,
10664     int oldtag,
10665     int* secondary_compat_out,
10666     int newtag,
10667     int secondary_compat)
10668 {
10669 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10670   static const int v6t2[] =
10671     {
10672       T(V6T2),   // PRE_V4.
10673       T(V6T2),   // V4.
10674       T(V6T2),   // V4T.
10675       T(V6T2),   // V5T.
10676       T(V6T2),   // V5TE.
10677       T(V6T2),   // V5TEJ.
10678       T(V6T2),   // V6.
10679       T(V7),     // V6KZ.
10680       T(V6T2)    // V6T2.
10681     };
10682   static const int v6k[] =
10683     {
10684       T(V6K),    // PRE_V4.
10685       T(V6K),    // V4.
10686       T(V6K),    // V4T.
10687       T(V6K),    // V5T.
10688       T(V6K),    // V5TE.
10689       T(V6K),    // V5TEJ.
10690       T(V6K),    // V6.
10691       T(V6KZ),   // V6KZ.
10692       T(V7),     // V6T2.
10693       T(V6K)     // V6K.
10694     };
10695   static const int v7[] =
10696     {
10697       T(V7),     // PRE_V4.
10698       T(V7),     // V4.
10699       T(V7),     // V4T.
10700       T(V7),     // V5T.
10701       T(V7),     // V5TE.
10702       T(V7),     // V5TEJ.
10703       T(V7),     // V6.
10704       T(V7),     // V6KZ.
10705       T(V7),     // V6T2.
10706       T(V7),     // V6K.
10707       T(V7)      // V7.
10708     };
10709   static const int v6_m[] =
10710     {
10711       -1,        // PRE_V4.
10712       -1,        // V4.
10713       T(V6K),    // V4T.
10714       T(V6K),    // V5T.
10715       T(V6K),    // V5TE.
10716       T(V6K),    // V5TEJ.
10717       T(V6K),    // V6.
10718       T(V6KZ),   // V6KZ.
10719       T(V7),     // V6T2.
10720       T(V6K),    // V6K.
10721       T(V7),     // V7.
10722       T(V6_M)    // V6_M.
10723     };
10724   static const int v6s_m[] =
10725     {
10726       -1,        // PRE_V4.
10727       -1,        // V4.
10728       T(V6K),    // V4T.
10729       T(V6K),    // V5T.
10730       T(V6K),    // V5TE.
10731       T(V6K),    // V5TEJ.
10732       T(V6K),    // V6.
10733       T(V6KZ),   // V6KZ.
10734       T(V7),     // V6T2.
10735       T(V6K),    // V6K.
10736       T(V7),     // V7.
10737       T(V6S_M),  // V6_M.
10738       T(V6S_M)   // V6S_M.
10739     };
10740   static const int v7e_m[] =
10741     {
10742       -1,       // PRE_V4.
10743       -1,       // V4.
10744       T(V7E_M), // V4T.
10745       T(V7E_M), // V5T.
10746       T(V7E_M), // V5TE.
10747       T(V7E_M), // V5TEJ.
10748       T(V7E_M), // V6.
10749       T(V7E_M), // V6KZ.
10750       T(V7E_M), // V6T2.
10751       T(V7E_M), // V6K.
10752       T(V7E_M), // V7.
10753       T(V7E_M), // V6_M.
10754       T(V7E_M), // V6S_M.
10755       T(V7E_M)  // V7E_M.
10756     };
10757   static const int v8[] =
10758     {
10759       T(V8),   // PRE_V4.
10760       T(V8),   // V4.
10761       T(V8),   // V4T.
10762       T(V8),   // V5T.
10763       T(V8),   // V5TE.
10764       T(V8),   // V5TEJ.
10765       T(V8),   // V6.
10766       T(V8),   // V6KZ.
10767       T(V8),   // V6T2.
10768       T(V8),   // V6K.
10769       T(V8),   // V7.
10770       T(V8),   // V6_M.
10771       T(V8),   // V6S_M.
10772       T(V8),   // V7E_M.
10773       T(V8)    // V8.
10774     };
10775   static const int v4t_plus_v6_m[] =
10776     {
10777       -1,               // PRE_V4.
10778       -1,               // V4.
10779       T(V4T),           // V4T.
10780       T(V5T),           // V5T.
10781       T(V5TE),          // V5TE.
10782       T(V5TEJ),         // V5TEJ.
10783       T(V6),            // V6.
10784       T(V6KZ),          // V6KZ.
10785       T(V6T2),          // V6T2.
10786       T(V6K),           // V6K.
10787       T(V7),            // V7.
10788       T(V6_M),          // V6_M.
10789       T(V6S_M),         // V6S_M.
10790       T(V7E_M),         // V7E_M.
10791       T(V8),            // V8.
10792       T(V4T_PLUS_V6_M)  // V4T plus V6_M.
10793     };
10794   static const int* comb[] =
10795     {
10796       v6t2,
10797       v6k,
10798       v7,
10799       v6_m,
10800       v6s_m,
10801       v7e_m,
10802       v8,
10803       // Pseudo-architecture.
10804       v4t_plus_v6_m
10805     };
10806
10807   // Check we've not got a higher architecture than we know about.
10808
10809   if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
10810     {
10811       gold_error(_("%s: unknown CPU architecture"), name);
10812       return -1;
10813     }
10814
10815   // Override old tag if we have a Tag_also_compatible_with on the output.
10816
10817   if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10818       || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10819     oldtag = T(V4T_PLUS_V6_M);
10820
10821   // And override the new tag if we have a Tag_also_compatible_with on the
10822   // input.
10823
10824   if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10825       || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10826     newtag = T(V4T_PLUS_V6_M);
10827
10828   // Architectures before V6KZ add features monotonically.
10829   int tagh = std::max(oldtag, newtag);
10830   if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10831     return tagh;
10832
10833   int tagl = std::min(oldtag, newtag);
10834   int result = comb[tagh - T(V6T2)][tagl];
10835
10836   // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10837   // as the canonical version.
10838   if (result == T(V4T_PLUS_V6_M))
10839     {
10840       result = T(V4T);
10841       *secondary_compat_out = T(V6_M);
10842     }
10843   else
10844     *secondary_compat_out = -1;
10845
10846   if (result == -1)
10847     {
10848       gold_error(_("%s: conflicting CPU architectures %d/%d"),
10849                  name, oldtag, newtag);
10850       return -1;
10851     }
10852
10853   return result;
10854 #undef T
10855 }
10856
10857 // Helper to print AEABI enum tag value.
10858
10859 template<bool big_endian>
10860 std::string
10861 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10862 {
10863   static const char* aeabi_enum_names[] =
10864     { "", "variable-size", "32-bit", "" };
10865   const size_t aeabi_enum_names_size =
10866     sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10867
10868   if (value < aeabi_enum_names_size)
10869     return std::string(aeabi_enum_names[value]);
10870   else
10871     {
10872       char buffer[100];
10873       sprintf(buffer, "<unknown value %u>", value);
10874       return std::string(buffer);
10875     }
10876 }
10877
10878 // Return the string value to store in TAG_CPU_name.
10879
10880 template<bool big_endian>
10881 std::string
10882 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10883 {
10884   static const char* name_table[] = {
10885     // These aren't real CPU names, but we can't guess
10886     // that from the architecture version alone.
10887    "Pre v4",
10888    "ARM v4",
10889    "ARM v4T",
10890    "ARM v5T",
10891    "ARM v5TE",
10892    "ARM v5TEJ",
10893    "ARM v6",
10894    "ARM v6KZ",
10895    "ARM v6T2",
10896    "ARM v6K",
10897    "ARM v7",
10898    "ARM v6-M",
10899    "ARM v6S-M",
10900    "ARM v7E-M",
10901    "ARM v8"
10902  };
10903  const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10904
10905   if (value < name_table_size)
10906     return std::string(name_table[value]);
10907   else
10908     {
10909       char buffer[100];
10910       sprintf(buffer, "<unknown CPU value %u>", value);
10911       return std::string(buffer);
10912     }
10913 }
10914
10915 // Query attributes object to see if integer divide instructions may be
10916 // present in an object.
10917
10918 template<bool big_endian>
10919 bool
10920 Target_arm<big_endian>::attributes_accept_div(int arch, int profile,
10921     const Object_attribute* div_attr)
10922 {
10923   switch (div_attr->int_value())
10924     {
10925     case 0:
10926       // Integer divide allowed if instruction contained in
10927       // archetecture.
10928       if (arch == elfcpp::TAG_CPU_ARCH_V7 && (profile == 'R' || profile == 'M'))
10929         return true;
10930       else if (arch >= elfcpp::TAG_CPU_ARCH_V7E_M)
10931         return true;
10932       else
10933         return false;
10934
10935     case 1:
10936       // Integer divide explicitly prohibited.
10937       return false;
10938
10939     default:
10940       // Unrecognised case - treat as allowing divide everywhere.
10941     case 2:
10942       // Integer divide allowed in ARM state.
10943       return true;
10944     }
10945 }
10946
10947 // Query attributes object to see if integer divide instructions are
10948 // forbidden to be in the object.  This is not the inverse of
10949 // attributes_accept_div.
10950
10951 template<bool big_endian>
10952 bool
10953 Target_arm<big_endian>::attributes_forbid_div(const Object_attribute* div_attr)
10954 {
10955   return div_attr->int_value() == 1;
10956 }
10957
10958 // Merge object attributes from input file called NAME with those of the
10959 // output.  The input object attributes are in the object pointed by PASD.
10960
10961 template<bool big_endian>
10962 void
10963 Target_arm<big_endian>::merge_object_attributes(
10964     const char* name,
10965     const Attributes_section_data* pasd)
10966 {
10967   // Return if there is no attributes section data.
10968   if (pasd == NULL)
10969     return;
10970
10971   // If output has no object attributes, just copy.
10972   const int vendor = Object_attribute::OBJ_ATTR_PROC;
10973   if (this->attributes_section_data_ == NULL)
10974     {
10975       this->attributes_section_data_ = new Attributes_section_data(*pasd);
10976       Object_attribute* out_attr =
10977         this->attributes_section_data_->known_attributes(vendor);
10978
10979       // We do not output objects with Tag_MPextension_use_legacy - we move
10980       //  the attribute's value to Tag_MPextension_use.  */
10981       if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10982         {
10983           if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10984               && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10985                 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10986             {
10987               gold_error(_("%s has both the current and legacy "
10988                            "Tag_MPextension_use attributes"),
10989                          name);
10990             }
10991
10992           out_attr[elfcpp::Tag_MPextension_use] =
10993             out_attr[elfcpp::Tag_MPextension_use_legacy];
10994           out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10995           out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10996         }
10997
10998       return;
10999     }
11000
11001   const Object_attribute* in_attr = pasd->known_attributes(vendor);
11002   Object_attribute* out_attr =
11003     this->attributes_section_data_->known_attributes(vendor);
11004
11005   // This needs to happen before Tag_ABI_FP_number_model is merged.  */
11006   if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
11007       != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
11008     {
11009       // Ignore mismatches if the object doesn't use floating point.  */
11010       if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
11011           == elfcpp::AEABI_FP_number_model_none
11012           || (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
11013               != elfcpp::AEABI_FP_number_model_none
11014               && out_attr[elfcpp::Tag_ABI_VFP_args].int_value()
11015                  == elfcpp::AEABI_VFP_args_compatible))
11016         out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
11017             in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
11018       else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
11019                != elfcpp::AEABI_FP_number_model_none
11020                && in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
11021                   != elfcpp::AEABI_VFP_args_compatible
11022                && parameters->options().warn_mismatch())
11023         gold_error(_("%s uses VFP register arguments, output does not"),
11024                    name);
11025     }
11026
11027   for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
11028     {
11029       // Merge this attribute with existing attributes.
11030       switch (i)
11031         {
11032         case elfcpp::Tag_CPU_raw_name:
11033         case elfcpp::Tag_CPU_name:
11034           // These are merged after Tag_CPU_arch.
11035           break;
11036
11037         case elfcpp::Tag_ABI_optimization_goals:
11038         case elfcpp::Tag_ABI_FP_optimization_goals:
11039           // Use the first value seen.
11040           break;
11041
11042         case elfcpp::Tag_CPU_arch:
11043           {
11044             unsigned int saved_out_attr = out_attr->int_value();
11045             // Merge Tag_CPU_arch and Tag_also_compatible_with.
11046             int secondary_compat =
11047               this->get_secondary_compatible_arch(pasd);
11048             int secondary_compat_out =
11049               this->get_secondary_compatible_arch(
11050                   this->attributes_section_data_);
11051             out_attr[i].set_int_value(
11052                 tag_cpu_arch_combine(name, out_attr[i].int_value(),
11053                                      &secondary_compat_out,
11054                                      in_attr[i].int_value(),
11055                                      secondary_compat));
11056             this->set_secondary_compatible_arch(this->attributes_section_data_,
11057                                                 secondary_compat_out);
11058
11059             // Merge Tag_CPU_name and Tag_CPU_raw_name.
11060             if (out_attr[i].int_value() == saved_out_attr)
11061               ; // Leave the names alone.
11062             else if (out_attr[i].int_value() == in_attr[i].int_value())
11063               {
11064                 // The output architecture has been changed to match the
11065                 // input architecture.  Use the input names.
11066                 out_attr[elfcpp::Tag_CPU_name].set_string_value(
11067                     in_attr[elfcpp::Tag_CPU_name].string_value());
11068                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
11069                     in_attr[elfcpp::Tag_CPU_raw_name].string_value());
11070               }
11071             else
11072               {
11073                 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
11074                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
11075               }
11076
11077             // If we still don't have a value for Tag_CPU_name,
11078             // make one up now.  Tag_CPU_raw_name remains blank.
11079             if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
11080               {
11081                 const std::string cpu_name =
11082                   this->tag_cpu_name_value(out_attr[i].int_value());
11083                 // FIXME:  If we see an unknown CPU, this will be set
11084                 // to "<unknown CPU n>", where n is the attribute value.
11085                 // This is different from BFD, which leaves the name alone.
11086                 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
11087               }
11088           }
11089           break;
11090
11091         case elfcpp::Tag_ARM_ISA_use:
11092         case elfcpp::Tag_THUMB_ISA_use:
11093         case elfcpp::Tag_WMMX_arch:
11094         case elfcpp::Tag_Advanced_SIMD_arch:
11095           // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
11096         case elfcpp::Tag_ABI_FP_rounding:
11097         case elfcpp::Tag_ABI_FP_exceptions:
11098         case elfcpp::Tag_ABI_FP_user_exceptions:
11099         case elfcpp::Tag_ABI_FP_number_model:
11100         case elfcpp::Tag_VFP_HP_extension:
11101         case elfcpp::Tag_CPU_unaligned_access:
11102         case elfcpp::Tag_T2EE_use:
11103         case elfcpp::Tag_Virtualization_use:
11104         case elfcpp::Tag_MPextension_use:
11105           // Use the largest value specified.
11106           if (in_attr[i].int_value() > out_attr[i].int_value())
11107             out_attr[i].set_int_value(in_attr[i].int_value());
11108           break;
11109
11110         case elfcpp::Tag_ABI_align8_preserved:
11111         case elfcpp::Tag_ABI_PCS_RO_data:
11112           // Use the smallest value specified.
11113           if (in_attr[i].int_value() < out_attr[i].int_value())
11114             out_attr[i].set_int_value(in_attr[i].int_value());
11115           break;
11116
11117         case elfcpp::Tag_ABI_align8_needed:
11118           if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
11119               && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
11120                   || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
11121                       == 0)))
11122             {
11123               // This error message should be enabled once all non-conforming
11124               // binaries in the toolchain have had the attributes set
11125               // properly.
11126               // gold_error(_("output 8-byte data alignment conflicts with %s"),
11127               //            name);
11128             }
11129           // Fall through.
11130         case elfcpp::Tag_ABI_FP_denormal:
11131         case elfcpp::Tag_ABI_PCS_GOT_use:
11132           {
11133             // These tags have 0 = don't care, 1 = strong requirement,
11134             // 2 = weak requirement.
11135             static const int order_021[3] = {0, 2, 1};
11136
11137             // Use the "greatest" from the sequence 0, 2, 1, or the largest
11138             // value if greater than 2 (for future-proofing).
11139             if ((in_attr[i].int_value() > 2
11140                  && in_attr[i].int_value() > out_attr[i].int_value())
11141                 || (in_attr[i].int_value() <= 2
11142                     && out_attr[i].int_value() <= 2
11143                     && (order_021[in_attr[i].int_value()]
11144                         > order_021[out_attr[i].int_value()])))
11145               out_attr[i].set_int_value(in_attr[i].int_value());
11146           }
11147           break;
11148
11149         case elfcpp::Tag_CPU_arch_profile:
11150           if (out_attr[i].int_value() != in_attr[i].int_value())
11151             {
11152               // 0 will merge with anything.
11153               // 'A' and 'S' merge to 'A'.
11154               // 'R' and 'S' merge to 'R'.
11155               // 'M' and 'A|R|S' is an error.
11156               if (out_attr[i].int_value() == 0
11157                   || (out_attr[i].int_value() == 'S'
11158                       && (in_attr[i].int_value() == 'A'
11159                           || in_attr[i].int_value() == 'R')))
11160                 out_attr[i].set_int_value(in_attr[i].int_value());
11161               else if (in_attr[i].int_value() == 0
11162                        || (in_attr[i].int_value() == 'S'
11163                            && (out_attr[i].int_value() == 'A'
11164                                || out_attr[i].int_value() == 'R')))
11165                 ; // Do nothing.
11166               else if (parameters->options().warn_mismatch())
11167                 {
11168                   gold_error
11169                     (_("conflicting architecture profiles %c/%c"),
11170                      in_attr[i].int_value() ? in_attr[i].int_value() : '0',
11171                      out_attr[i].int_value() ? out_attr[i].int_value() : '0');
11172                 }
11173             }
11174           break;
11175         case elfcpp::Tag_VFP_arch:
11176             {
11177               static const struct
11178               {
11179                   int ver;
11180                   int regs;
11181               } vfp_versions[7] =
11182                 {
11183                   {0, 0},
11184                   {1, 16},
11185                   {2, 16},
11186                   {3, 32},
11187                   {3, 16},
11188                   {4, 32},
11189                   {4, 16}
11190                 };
11191
11192               // Values greater than 6 aren't defined, so just pick the
11193               // biggest.
11194               if (in_attr[i].int_value() > 6
11195                   && in_attr[i].int_value() > out_attr[i].int_value())
11196                 {
11197                   *out_attr = *in_attr;
11198                   break;
11199                 }
11200               // The output uses the superset of input features
11201               // (ISA version) and registers.
11202               int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
11203                                  vfp_versions[out_attr[i].int_value()].ver);
11204               int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
11205                                   vfp_versions[out_attr[i].int_value()].regs);
11206               // This assumes all possible supersets are also a valid
11207               // options.
11208               int newval;
11209               for (newval = 6; newval > 0; newval--)
11210                 {
11211                   if (regs == vfp_versions[newval].regs
11212                       && ver == vfp_versions[newval].ver)
11213                     break;
11214                 }
11215               out_attr[i].set_int_value(newval);
11216             }
11217           break;
11218         case elfcpp::Tag_PCS_config:
11219           if (out_attr[i].int_value() == 0)
11220             out_attr[i].set_int_value(in_attr[i].int_value());
11221           else if (in_attr[i].int_value() != 0
11222                    && out_attr[i].int_value() != 0
11223                    && parameters->options().warn_mismatch())
11224             {
11225               // It's sometimes ok to mix different configs, so this is only
11226               // a warning.
11227               gold_warning(_("%s: conflicting platform configuration"), name);
11228             }
11229           break;
11230         case elfcpp::Tag_ABI_PCS_R9_use:
11231           if (in_attr[i].int_value() != out_attr[i].int_value()
11232               && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
11233               && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
11234               && parameters->options().warn_mismatch())
11235             {
11236               gold_error(_("%s: conflicting use of R9"), name);
11237             }
11238           if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
11239             out_attr[i].set_int_value(in_attr[i].int_value());
11240           break;
11241         case elfcpp::Tag_ABI_PCS_RW_data:
11242           if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
11243               && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
11244                   != elfcpp::AEABI_R9_SB)
11245               && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
11246                   != elfcpp::AEABI_R9_unused)
11247               && parameters->options().warn_mismatch())
11248             {
11249               gold_error(_("%s: SB relative addressing conflicts with use "
11250                            "of R9"),
11251                            name);
11252             }
11253           // Use the smallest value specified.
11254           if (in_attr[i].int_value() < out_attr[i].int_value())
11255             out_attr[i].set_int_value(in_attr[i].int_value());
11256           break;
11257         case elfcpp::Tag_ABI_PCS_wchar_t:
11258           if (out_attr[i].int_value()
11259               && in_attr[i].int_value()
11260               && out_attr[i].int_value() != in_attr[i].int_value()
11261               && parameters->options().warn_mismatch()
11262               && parameters->options().wchar_size_warning())
11263             {
11264               gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
11265                              "use %u-byte wchar_t; use of wchar_t values "
11266                              "across objects may fail"),
11267                            name, in_attr[i].int_value(),
11268                            out_attr[i].int_value());
11269             }
11270           else if (in_attr[i].int_value() && !out_attr[i].int_value())
11271             out_attr[i].set_int_value(in_attr[i].int_value());
11272           break;
11273         case elfcpp::Tag_ABI_enum_size:
11274           if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
11275             {
11276               if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
11277                   || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
11278                 {
11279                   // The existing object is compatible with anything.
11280                   // Use whatever requirements the new object has.
11281                   out_attr[i].set_int_value(in_attr[i].int_value());
11282                 }
11283               else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
11284                        && out_attr[i].int_value() != in_attr[i].int_value()
11285                        && parameters->options().warn_mismatch()
11286                        && parameters->options().enum_size_warning())
11287                 {
11288                   unsigned int in_value = in_attr[i].int_value();
11289                   unsigned int out_value = out_attr[i].int_value();
11290                   gold_warning(_("%s uses %s enums yet the output is to use "
11291                                  "%s enums; use of enum values across objects "
11292                                  "may fail"),
11293                                name,
11294                                this->aeabi_enum_name(in_value).c_str(),
11295                                this->aeabi_enum_name(out_value).c_str());
11296                 }
11297             }
11298           break;
11299         case elfcpp::Tag_ABI_VFP_args:
11300           // Already done.
11301           break;
11302         case elfcpp::Tag_ABI_WMMX_args:
11303           if (in_attr[i].int_value() != out_attr[i].int_value()
11304               && parameters->options().warn_mismatch())
11305             {
11306               gold_error(_("%s uses iWMMXt register arguments, output does "
11307                            "not"),
11308                          name);
11309             }
11310           break;
11311         case Object_attribute::Tag_compatibility:
11312           // Merged in target-independent code.
11313           break;
11314         case elfcpp::Tag_ABI_HardFP_use:
11315           // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
11316           if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
11317               || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
11318             out_attr[i].set_int_value(3);
11319           else if (in_attr[i].int_value() > out_attr[i].int_value())
11320             out_attr[i].set_int_value(in_attr[i].int_value());
11321           break;
11322         case elfcpp::Tag_ABI_FP_16bit_format:
11323           if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
11324             {
11325               if (in_attr[i].int_value() != out_attr[i].int_value()
11326                   && parameters->options().warn_mismatch())
11327                 gold_error(_("fp16 format mismatch between %s and output"),
11328                            name);
11329             }
11330           if (in_attr[i].int_value() != 0)
11331             out_attr[i].set_int_value(in_attr[i].int_value());
11332           break;
11333
11334         case elfcpp::Tag_DIV_use:
11335           {
11336             // A value of zero on input means that the divide
11337             // instruction may be used if available in the base
11338             // architecture as specified via Tag_CPU_arch and
11339             // Tag_CPU_arch_profile.  A value of 1 means that the user
11340             // did not want divide instructions.  A value of 2
11341             // explicitly means that divide instructions were allowed
11342             // in ARM and Thumb state.
11343             int arch = this->
11344               get_aeabi_object_attribute(elfcpp::Tag_CPU_arch)->
11345               int_value();
11346             int profile = this->
11347               get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile)->
11348               int_value();
11349             if (in_attr[i].int_value() == out_attr[i].int_value())
11350               {
11351                 // Do nothing.
11352               }
11353             else if (attributes_forbid_div(&in_attr[i])
11354                      && !attributes_accept_div(arch, profile, &out_attr[i]))
11355               out_attr[i].set_int_value(1);
11356             else if (attributes_forbid_div(&out_attr[i])
11357                      && attributes_accept_div(arch, profile, &in_attr[i]))
11358               out_attr[i].set_int_value(in_attr[i].int_value());
11359             else if (in_attr[i].int_value() == 2)
11360               out_attr[i].set_int_value(in_attr[i].int_value());
11361           }
11362           break;
11363
11364         case elfcpp::Tag_MPextension_use_legacy:
11365           // We don't output objects with Tag_MPextension_use_legacy - we
11366           // move the value to Tag_MPextension_use.
11367           if (in_attr[i].int_value() != 0
11368               && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
11369             {
11370               if (in_attr[elfcpp::Tag_MPextension_use].int_value()
11371                   != in_attr[i].int_value())
11372                 {
11373                   gold_error(_("%s has has both the current and legacy "
11374                                "Tag_MPextension_use attributes"),
11375                              name);
11376                 }
11377             }
11378
11379           if (in_attr[i].int_value()
11380               > out_attr[elfcpp::Tag_MPextension_use].int_value())
11381             out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
11382
11383           break;
11384
11385         case elfcpp::Tag_nodefaults:
11386           // This tag is set if it exists, but the value is unused (and is
11387           // typically zero).  We don't actually need to do anything here -
11388           // the merge happens automatically when the type flags are merged
11389           // below.
11390           break;
11391         case elfcpp::Tag_also_compatible_with:
11392           // Already done in Tag_CPU_arch.
11393           break;
11394         case elfcpp::Tag_conformance:
11395           // Keep the attribute if it matches.  Throw it away otherwise.
11396           // No attribute means no claim to conform.
11397           if (in_attr[i].string_value() != out_attr[i].string_value())
11398             out_attr[i].set_string_value("");
11399           break;
11400
11401         default:
11402           {
11403             const char* err_object = NULL;
11404
11405             // The "known_obj_attributes" table does contain some undefined
11406             // attributes.  Ensure that there are unused.
11407             if (out_attr[i].int_value() != 0
11408                 || out_attr[i].string_value() != "")
11409               err_object = "output";
11410             else if (in_attr[i].int_value() != 0
11411                      || in_attr[i].string_value() != "")
11412               err_object = name;
11413
11414             if (err_object != NULL
11415                 && parameters->options().warn_mismatch())
11416               {
11417                 // Attribute numbers >=64 (mod 128) can be safely ignored.
11418                 if ((i & 127) < 64)
11419                   gold_error(_("%s: unknown mandatory EABI object attribute "
11420                                "%d"),
11421                              err_object, i);
11422                 else
11423                   gold_warning(_("%s: unknown EABI object attribute %d"),
11424                                err_object, i);
11425               }
11426
11427             // Only pass on attributes that match in both inputs.
11428             if (!in_attr[i].matches(out_attr[i]))
11429               {
11430                 out_attr[i].set_int_value(0);
11431                 out_attr[i].set_string_value("");
11432               }
11433           }
11434         }
11435
11436       // If out_attr was copied from in_attr then it won't have a type yet.
11437       if (in_attr[i].type() && !out_attr[i].type())
11438         out_attr[i].set_type(in_attr[i].type());
11439     }
11440
11441   // Merge Tag_compatibility attributes and any common GNU ones.
11442   this->attributes_section_data_->merge(name, pasd);
11443
11444   // Check for any attributes not known on ARM.
11445   typedef Vendor_object_attributes::Other_attributes Other_attributes;
11446   const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
11447   Other_attributes::const_iterator in_iter = in_other_attributes->begin();
11448   Other_attributes* out_other_attributes =
11449     this->attributes_section_data_->other_attributes(vendor);
11450   Other_attributes::iterator out_iter = out_other_attributes->begin();
11451
11452   while (in_iter != in_other_attributes->end()
11453          || out_iter != out_other_attributes->end())
11454     {
11455       const char* err_object = NULL;
11456       int err_tag = 0;
11457
11458       // The tags for each list are in numerical order.
11459       // If the tags are equal, then merge.
11460       if (out_iter != out_other_attributes->end()
11461           && (in_iter == in_other_attributes->end()
11462               || in_iter->first > out_iter->first))
11463         {
11464           // This attribute only exists in output.  We can't merge, and we
11465           // don't know what the tag means, so delete it.
11466           err_object = "output";
11467           err_tag = out_iter->first;
11468           int saved_tag = out_iter->first;
11469           delete out_iter->second;
11470           out_other_attributes->erase(out_iter);
11471           out_iter = out_other_attributes->upper_bound(saved_tag);
11472         }
11473       else if (in_iter != in_other_attributes->end()
11474                && (out_iter != out_other_attributes->end()
11475                    || in_iter->first < out_iter->first))
11476         {
11477           // This attribute only exists in input. We can't merge, and we
11478           // don't know what the tag means, so ignore it.
11479           err_object = name;
11480           err_tag = in_iter->first;
11481           ++in_iter;
11482         }
11483       else // The tags are equal.
11484         {
11485           // As present, all attributes in the list are unknown, and
11486           // therefore can't be merged meaningfully.
11487           err_object = "output";
11488           err_tag = out_iter->first;
11489
11490           //  Only pass on attributes that match in both inputs.
11491           if (!in_iter->second->matches(*(out_iter->second)))
11492             {
11493               // No match.  Delete the attribute.
11494               int saved_tag = out_iter->first;
11495               delete out_iter->second;
11496               out_other_attributes->erase(out_iter);
11497               out_iter = out_other_attributes->upper_bound(saved_tag);
11498             }
11499           else
11500             {
11501               // Matched.  Keep the attribute and move to the next.
11502               ++out_iter;
11503               ++in_iter;
11504             }
11505         }
11506
11507       if (err_object && parameters->options().warn_mismatch())
11508         {
11509           // Attribute numbers >=64 (mod 128) can be safely ignored.  */
11510           if ((err_tag & 127) < 64)
11511             {
11512               gold_error(_("%s: unknown mandatory EABI object attribute %d"),
11513                          err_object, err_tag);
11514             }
11515           else
11516             {
11517               gold_warning(_("%s: unknown EABI object attribute %d"),
11518                            err_object, err_tag);
11519             }
11520         }
11521     }
11522 }
11523
11524 // Stub-generation methods for Target_arm.
11525
11526 // Make a new Arm_input_section object.
11527
11528 template<bool big_endian>
11529 Arm_input_section<big_endian>*
11530 Target_arm<big_endian>::new_arm_input_section(
11531     Relobj* relobj,
11532     unsigned int shndx)
11533 {
11534   Section_id sid(relobj, shndx);
11535
11536   Arm_input_section<big_endian>* arm_input_section =
11537     new Arm_input_section<big_endian>(relobj, shndx);
11538   arm_input_section->init();
11539
11540   // Register new Arm_input_section in map for look-up.
11541   std::pair<typename Arm_input_section_map::iterator, bool> ins =
11542     this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
11543
11544   // Make sure that it we have not created another Arm_input_section
11545   // for this input section already.
11546   gold_assert(ins.second);
11547
11548   return arm_input_section;
11549 }
11550
11551 // Find the Arm_input_section object corresponding to the SHNDX-th input
11552 // section of RELOBJ.
11553
11554 template<bool big_endian>
11555 Arm_input_section<big_endian>*
11556 Target_arm<big_endian>::find_arm_input_section(
11557     Relobj* relobj,
11558     unsigned int shndx) const
11559 {
11560   Section_id sid(relobj, shndx);
11561   typename Arm_input_section_map::const_iterator p =
11562     this->arm_input_section_map_.find(sid);
11563   return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
11564 }
11565
11566 // Make a new stub table.
11567
11568 template<bool big_endian>
11569 Stub_table<big_endian>*
11570 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
11571 {
11572   Stub_table<big_endian>* stub_table =
11573     new Stub_table<big_endian>(owner);
11574   this->stub_tables_.push_back(stub_table);
11575
11576   stub_table->set_address(owner->address() + owner->data_size());
11577   stub_table->set_file_offset(owner->offset() + owner->data_size());
11578   stub_table->finalize_data_size();
11579
11580   return stub_table;
11581 }
11582
11583 // Scan a relocation for stub generation.
11584
11585 template<bool big_endian>
11586 void
11587 Target_arm<big_endian>::scan_reloc_for_stub(
11588     const Relocate_info<32, big_endian>* relinfo,
11589     unsigned int r_type,
11590     const Sized_symbol<32>* gsym,
11591     unsigned int r_sym,
11592     const Symbol_value<32>* psymval,
11593     elfcpp::Elf_types<32>::Elf_Swxword addend,
11594     Arm_address address)
11595 {
11596   const Arm_relobj<big_endian>* arm_relobj =
11597     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11598
11599   bool target_is_thumb;
11600   Symbol_value<32> symval;
11601   if (gsym != NULL)
11602     {
11603       // This is a global symbol.  Determine if we use PLT and if the
11604       // final target is THUMB.
11605       if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
11606         {
11607           // This uses a PLT, change the symbol value.
11608           symval.set_output_value(this->plt_address_for_global(gsym));
11609           psymval = &symval;
11610           target_is_thumb = false;
11611         }
11612       else if (gsym->is_undefined())
11613         // There is no need to generate a stub symbol is undefined.
11614         return;
11615       else
11616         {
11617           target_is_thumb =
11618             ((gsym->type() == elfcpp::STT_ARM_TFUNC)
11619              || (gsym->type() == elfcpp::STT_FUNC
11620                  && !gsym->is_undefined()
11621                  && ((psymval->value(arm_relobj, 0) & 1) != 0)));
11622         }
11623     }
11624   else
11625     {
11626       // This is a local symbol.  Determine if the final target is THUMB.
11627       target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
11628     }
11629
11630   // Strip LSB if this points to a THUMB target.
11631   const Arm_reloc_property* reloc_property =
11632     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
11633   gold_assert(reloc_property != NULL);
11634   if (target_is_thumb
11635       && reloc_property->uses_thumb_bit()
11636       && ((psymval->value(arm_relobj, 0) & 1) != 0))
11637     {
11638       Arm_address stripped_value =
11639         psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
11640       symval.set_output_value(stripped_value);
11641       psymval = &symval;
11642     }
11643
11644   // Get the symbol value.
11645   Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
11646
11647   // Owing to pipelining, the PC relative branches below actually skip
11648   // two instructions when the branch offset is 0.
11649   Arm_address destination;
11650   switch (r_type)
11651     {
11652     case elfcpp::R_ARM_CALL:
11653     case elfcpp::R_ARM_JUMP24:
11654     case elfcpp::R_ARM_PLT32:
11655       // ARM branches.
11656       destination = value + addend + 8;
11657       break;
11658     case elfcpp::R_ARM_THM_CALL:
11659     case elfcpp::R_ARM_THM_XPC22:
11660     case elfcpp::R_ARM_THM_JUMP24:
11661     case elfcpp::R_ARM_THM_JUMP19:
11662       // THUMB branches.
11663       destination = value + addend + 4;
11664       break;
11665     default:
11666       gold_unreachable();
11667     }
11668
11669   Reloc_stub* stub = NULL;
11670   Stub_type stub_type =
11671     Reloc_stub::stub_type_for_reloc(r_type, address, destination,
11672                                     target_is_thumb);
11673   if (stub_type != arm_stub_none)
11674     {
11675       // Try looking up an existing stub from a stub table.
11676       Stub_table<big_endian>* stub_table =
11677         arm_relobj->stub_table(relinfo->data_shndx);
11678       gold_assert(stub_table != NULL);
11679
11680       // Locate stub by destination.
11681       Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
11682
11683       // Create a stub if there is not one already
11684       stub = stub_table->find_reloc_stub(stub_key);
11685       if (stub == NULL)
11686         {
11687           // create a new stub and add it to stub table.
11688           stub = this->stub_factory().make_reloc_stub(stub_type);
11689           stub_table->add_reloc_stub(stub, stub_key);
11690         }
11691
11692       // Record the destination address.
11693       stub->set_destination_address(destination
11694                                     | (target_is_thumb ? 1 : 0));
11695     }
11696
11697   // For Cortex-A8, we need to record a relocation at 4K page boundary.
11698   if (this->fix_cortex_a8_
11699       && (r_type == elfcpp::R_ARM_THM_JUMP24
11700           || r_type == elfcpp::R_ARM_THM_JUMP19
11701           || r_type == elfcpp::R_ARM_THM_CALL
11702           || r_type == elfcpp::R_ARM_THM_XPC22)
11703       && (address & 0xfffU) == 0xffeU)
11704     {
11705       // Found a candidate.  Note we haven't checked the destination is
11706       // within 4K here: if we do so (and don't create a record) we can't
11707       // tell that a branch should have been relocated when scanning later.
11708       this->cortex_a8_relocs_info_[address] =
11709         new Cortex_a8_reloc(stub, r_type,
11710                             destination | (target_is_thumb ? 1 : 0));
11711     }
11712 }
11713
11714 // This function scans a relocation sections for stub generation.
11715 // The template parameter Relocate must be a class type which provides
11716 // a single function, relocate(), which implements the machine
11717 // specific part of a relocation.
11718
11719 // BIG_ENDIAN is the endianness of the data.  SH_TYPE is the section type:
11720 // SHT_REL or SHT_RELA.
11721
11722 // PRELOCS points to the relocation data.  RELOC_COUNT is the number
11723 // of relocs.  OUTPUT_SECTION is the output section.
11724 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
11725 // mapped to output offsets.
11726
11727 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
11728 // VIEW_SIZE is the size.  These refer to the input section, unless
11729 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
11730 // the output section.
11731
11732 template<bool big_endian>
11733 template<int sh_type>
11734 void inline
11735 Target_arm<big_endian>::scan_reloc_section_for_stubs(
11736     const Relocate_info<32, big_endian>* relinfo,
11737     const unsigned char* prelocs,
11738     size_t reloc_count,
11739     Output_section* output_section,
11740     bool needs_special_offset_handling,
11741     const unsigned char* view,
11742     elfcpp::Elf_types<32>::Elf_Addr view_address,
11743     section_size_type)
11744 {
11745   typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
11746   const int reloc_size =
11747     Reloc_types<sh_type, 32, big_endian>::reloc_size;
11748
11749   Arm_relobj<big_endian>* arm_object =
11750     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11751   unsigned int local_count = arm_object->local_symbol_count();
11752
11753   gold::Default_comdat_behavior default_comdat_behavior;
11754   Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11755
11756   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11757     {
11758       Reltype reloc(prelocs);
11759
11760       typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11761       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11762       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11763
11764       r_type = this->get_real_reloc_type(r_type);
11765
11766       // Only a few relocation types need stubs.
11767       if ((r_type != elfcpp::R_ARM_CALL)
11768          && (r_type != elfcpp::R_ARM_JUMP24)
11769          && (r_type != elfcpp::R_ARM_PLT32)
11770          && (r_type != elfcpp::R_ARM_THM_CALL)
11771          && (r_type != elfcpp::R_ARM_THM_XPC22)
11772          && (r_type != elfcpp::R_ARM_THM_JUMP24)
11773          && (r_type != elfcpp::R_ARM_THM_JUMP19)
11774          && (r_type != elfcpp::R_ARM_V4BX))
11775         continue;
11776
11777       section_offset_type offset =
11778         convert_to_section_size_type(reloc.get_r_offset());
11779
11780       if (needs_special_offset_handling)
11781         {
11782           offset = output_section->output_offset(relinfo->object,
11783                                                  relinfo->data_shndx,
11784                                                  offset);
11785           if (offset == -1)
11786             continue;
11787         }
11788
11789       // Create a v4bx stub if --fix-v4bx-interworking is used.
11790       if (r_type == elfcpp::R_ARM_V4BX)
11791         {
11792           if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11793             {
11794               // Get the BX instruction.
11795               typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11796               const Valtype* wv =
11797                 reinterpret_cast<const Valtype*>(view + offset);
11798               elfcpp::Elf_types<32>::Elf_Swxword insn =
11799                 elfcpp::Swap<32, big_endian>::readval(wv);
11800               const uint32_t reg = (insn & 0xf);
11801
11802               if (reg < 0xf)
11803                 {
11804                   // Try looking up an existing stub from a stub table.
11805                   Stub_table<big_endian>* stub_table =
11806                     arm_object->stub_table(relinfo->data_shndx);
11807                   gold_assert(stub_table != NULL);
11808
11809                   if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11810                     {
11811                       // create a new stub and add it to stub table.
11812                       Arm_v4bx_stub* stub =
11813                         this->stub_factory().make_arm_v4bx_stub(reg);
11814                       gold_assert(stub != NULL);
11815                       stub_table->add_arm_v4bx_stub(stub);
11816                     }
11817                 }
11818             }
11819           continue;
11820         }
11821
11822       // Get the addend.
11823       Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11824       elfcpp::Elf_types<32>::Elf_Swxword addend =
11825         stub_addend_reader(r_type, view + offset, reloc);
11826
11827       const Sized_symbol<32>* sym;
11828
11829       Symbol_value<32> symval;
11830       const Symbol_value<32> *psymval;
11831       bool is_defined_in_discarded_section;
11832       unsigned int shndx;
11833       if (r_sym < local_count)
11834         {
11835           sym = NULL;
11836           psymval = arm_object->local_symbol(r_sym);
11837
11838           // If the local symbol belongs to a section we are discarding,
11839           // and that section is a debug section, try to find the
11840           // corresponding kept section and map this symbol to its
11841           // counterpart in the kept section.  The symbol must not
11842           // correspond to a section we are folding.
11843           bool is_ordinary;
11844           shndx = psymval->input_shndx(&is_ordinary);
11845           is_defined_in_discarded_section =
11846             (is_ordinary
11847              && shndx != elfcpp::SHN_UNDEF
11848              && !arm_object->is_section_included(shndx)
11849              && !relinfo->symtab->is_section_folded(arm_object, shndx));
11850
11851           // We need to compute the would-be final value of this local
11852           // symbol.
11853           if (!is_defined_in_discarded_section)
11854             {
11855               typedef Sized_relobj_file<32, big_endian> ObjType;
11856               typename ObjType::Compute_final_local_value_status status =
11857                 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11858                                                       relinfo->symtab);
11859               if (status == ObjType::CFLV_OK)
11860                 {
11861                   // Currently we cannot handle a branch to a target in
11862                   // a merged section.  If this is the case, issue an error
11863                   // and also free the merge symbol value.
11864                   if (!symval.has_output_value())
11865                     {
11866                       const std::string& section_name =
11867                         arm_object->section_name(shndx);
11868                       arm_object->error(_("cannot handle branch to local %u "
11869                                           "in a merged section %s"),
11870                                         r_sym, section_name.c_str());
11871                     }
11872                   psymval = &symval;
11873                 }
11874               else
11875                 {
11876                   // We cannot determine the final value.
11877                   continue;
11878                 }
11879             }
11880         }
11881       else
11882         {
11883           const Symbol* gsym;
11884           gsym = arm_object->global_symbol(r_sym);
11885           gold_assert(gsym != NULL);
11886           if (gsym->is_forwarder())
11887             gsym = relinfo->symtab->resolve_forwards(gsym);
11888
11889           sym = static_cast<const Sized_symbol<32>*>(gsym);
11890           if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11891             symval.set_output_symtab_index(sym->symtab_index());
11892           else
11893             symval.set_no_output_symtab_entry();
11894
11895           // We need to compute the would-be final value of this global
11896           // symbol.
11897           const Symbol_table* symtab = relinfo->symtab;
11898           const Sized_symbol<32>* sized_symbol =
11899             symtab->get_sized_symbol<32>(gsym);
11900           Symbol_table::Compute_final_value_status status;
11901           Arm_address value =
11902             symtab->compute_final_value<32>(sized_symbol, &status);
11903
11904           // Skip this if the symbol has not output section.
11905           if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11906             continue;
11907           symval.set_output_value(value);
11908
11909           if (gsym->type() == elfcpp::STT_TLS)
11910             symval.set_is_tls_symbol();
11911           else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11912             symval.set_is_ifunc_symbol();
11913           psymval = &symval;
11914
11915           is_defined_in_discarded_section =
11916             (gsym->is_defined_in_discarded_section()
11917              && gsym->is_undefined());
11918           shndx = 0;
11919         }
11920
11921       Symbol_value<32> symval2;
11922       if (is_defined_in_discarded_section)
11923         {
11924           if (comdat_behavior == CB_UNDETERMINED)
11925             {
11926               std::string name = arm_object->section_name(relinfo->data_shndx);
11927               comdat_behavior = default_comdat_behavior.get(name.c_str());
11928             }
11929           if (comdat_behavior == CB_PRETEND)
11930             {
11931               // FIXME: This case does not work for global symbols.
11932               // We have no place to store the original section index.
11933               // Fortunately this does not matter for comdat sections,
11934               // only for sections explicitly discarded by a linker
11935               // script.
11936               bool found;
11937               typename elfcpp::Elf_types<32>::Elf_Addr value =
11938                 arm_object->map_to_kept_section(shndx, &found);
11939               if (found)
11940                 symval2.set_output_value(value + psymval->input_value());
11941               else
11942                 symval2.set_output_value(0);
11943             }
11944           else
11945             {
11946               if (comdat_behavior == CB_WARNING)
11947                 gold_warning_at_location(relinfo, i, offset,
11948                                          _("relocation refers to discarded "
11949                                            "section"));
11950               symval2.set_output_value(0);
11951             }
11952           symval2.set_no_output_symtab_entry();
11953           psymval = &symval2;
11954         }
11955
11956       // If symbol is a section symbol, we don't know the actual type of
11957       // destination.  Give up.
11958       if (psymval->is_section_symbol())
11959         continue;
11960
11961       this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11962                                 addend, view_address + offset);
11963     }
11964 }
11965
11966 // Scan an input section for stub generation.
11967
11968 template<bool big_endian>
11969 void
11970 Target_arm<big_endian>::scan_section_for_stubs(
11971     const Relocate_info<32, big_endian>* relinfo,
11972     unsigned int sh_type,
11973     const unsigned char* prelocs,
11974     size_t reloc_count,
11975     Output_section* output_section,
11976     bool needs_special_offset_handling,
11977     const unsigned char* view,
11978     Arm_address view_address,
11979     section_size_type view_size)
11980 {
11981   if (sh_type == elfcpp::SHT_REL)
11982     this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11983         relinfo,
11984         prelocs,
11985         reloc_count,
11986         output_section,
11987         needs_special_offset_handling,
11988         view,
11989         view_address,
11990         view_size);
11991   else if (sh_type == elfcpp::SHT_RELA)
11992     // We do not support RELA type relocations yet.  This is provided for
11993     // completeness.
11994     this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11995         relinfo,
11996         prelocs,
11997         reloc_count,
11998         output_section,
11999         needs_special_offset_handling,
12000         view,
12001         view_address,
12002         view_size);
12003   else
12004     gold_unreachable();
12005 }
12006
12007 // Group input sections for stub generation.
12008 //
12009 // We group input sections in an output section so that the total size,
12010 // including any padding space due to alignment is smaller than GROUP_SIZE
12011 // unless the only input section in group is bigger than GROUP_SIZE already.
12012 // Then an ARM stub table is created to follow the last input section
12013 // in group.  For each group an ARM stub table is created an is placed
12014 // after the last group.  If STUB_ALWAYS_AFTER_BRANCH is false, we further
12015 // extend the group after the stub table.
12016
12017 template<bool big_endian>
12018 void
12019 Target_arm<big_endian>::group_sections(
12020     Layout* layout,
12021     section_size_type group_size,
12022     bool stubs_always_after_branch,
12023     const Task* task)
12024 {
12025   // Group input sections and insert stub table
12026   Layout::Section_list section_list;
12027   layout->get_executable_sections(&section_list);
12028   for (Layout::Section_list::const_iterator p = section_list.begin();
12029        p != section_list.end();
12030        ++p)
12031     {
12032       Arm_output_section<big_endian>* output_section =
12033         Arm_output_section<big_endian>::as_arm_output_section(*p);
12034       output_section->group_sections(group_size, stubs_always_after_branch,
12035                                      this, task);
12036     }
12037 }
12038
12039 // Relaxation hook.  This is where we do stub generation.
12040
12041 template<bool big_endian>
12042 bool
12043 Target_arm<big_endian>::do_relax(
12044     int pass,
12045     const Input_objects* input_objects,
12046     Symbol_table* symtab,
12047     Layout* layout,
12048     const Task* task)
12049 {
12050   // No need to generate stubs if this is a relocatable link.
12051   gold_assert(!parameters->options().relocatable());
12052
12053   // If this is the first pass, we need to group input sections into
12054   // stub groups.
12055   bool done_exidx_fixup = false;
12056   typedef typename Stub_table_list::iterator Stub_table_iterator;
12057   if (pass == 1)
12058     {
12059       // Determine the stub group size.  The group size is the absolute
12060       // value of the parameter --stub-group-size.  If --stub-group-size
12061       // is passed a negative value, we restrict stubs to be always after
12062       // the stubbed branches.
12063       int32_t stub_group_size_param =
12064         parameters->options().stub_group_size();
12065       bool stubs_always_after_branch = stub_group_size_param < 0;
12066       section_size_type stub_group_size = abs(stub_group_size_param);
12067
12068       if (stub_group_size == 1)
12069         {
12070           // Default value.
12071           // Thumb branch range is +-4MB has to be used as the default
12072           // maximum size (a given section can contain both ARM and Thumb
12073           // code, so the worst case has to be taken into account).  If we are
12074           // fixing cortex-a8 errata, the branch range has to be even smaller,
12075           // since wide conditional branch has a range of +-1MB only.
12076           //
12077           // This value is 48K less than that, which allows for 4096
12078           // 12-byte stubs.  If we exceed that, then we will fail to link.
12079           // The user will have to relink with an explicit group size
12080           // option.
12081             stub_group_size = 4145152;
12082         }
12083
12084       // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
12085       // page as the first half of a 32-bit branch straddling two 4K pages.
12086       // This is a crude way of enforcing that.  In addition, long conditional
12087       // branches of THUMB-2 have a range of +-1M.  If we are fixing cortex-A8
12088       // erratum, limit the group size to  (1M - 12k) to avoid unreachable
12089       // cortex-A8 stubs from long conditional branches.
12090       if (this->fix_cortex_a8_)
12091         {
12092           stubs_always_after_branch = true;
12093           const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
12094           stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
12095         }
12096
12097       group_sections(layout, stub_group_size, stubs_always_after_branch, task);
12098
12099       // Also fix .ARM.exidx section coverage.
12100       Arm_output_section<big_endian>* exidx_output_section = NULL;
12101       for (Layout::Section_list::const_iterator p =
12102              layout->section_list().begin();
12103            p != layout->section_list().end();
12104            ++p)
12105         if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
12106           {
12107             if (exidx_output_section == NULL)
12108               exidx_output_section =
12109                 Arm_output_section<big_endian>::as_arm_output_section(*p);
12110             else
12111               // We cannot handle this now.
12112               gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
12113                            "non-relocatable link"),
12114                           exidx_output_section->name(),
12115                           (*p)->name());
12116           }
12117
12118       if (exidx_output_section != NULL)
12119         {
12120           this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
12121                                    symtab, task);
12122           done_exidx_fixup = true;
12123         }
12124     }
12125   else
12126     {
12127       // If this is not the first pass, addresses and file offsets have
12128       // been reset at this point, set them here.
12129       for (Stub_table_iterator sp = this->stub_tables_.begin();
12130            sp != this->stub_tables_.end();
12131            ++sp)
12132         {
12133           Arm_input_section<big_endian>* owner = (*sp)->owner();
12134           off_t off = align_address(owner->original_size(),
12135                                     (*sp)->addralign());
12136           (*sp)->set_address_and_file_offset(owner->address() + off,
12137                                              owner->offset() + off);
12138         }
12139     }
12140
12141   // The Cortex-A8 stubs are sensitive to layout of code sections.  At the
12142   // beginning of each relaxation pass, just blow away all the stubs.
12143   // Alternatively, we could selectively remove only the stubs and reloc
12144   // information for code sections that have moved since the last pass.
12145   // That would require more book-keeping.
12146   if (this->fix_cortex_a8_)
12147     {
12148       // Clear all Cortex-A8 reloc information.
12149       for (typename Cortex_a8_relocs_info::const_iterator p =
12150              this->cortex_a8_relocs_info_.begin();
12151            p != this->cortex_a8_relocs_info_.end();
12152            ++p)
12153         delete p->second;
12154       this->cortex_a8_relocs_info_.clear();
12155
12156       // Remove all Cortex-A8 stubs.
12157       for (Stub_table_iterator sp = this->stub_tables_.begin();
12158            sp != this->stub_tables_.end();
12159            ++sp)
12160         (*sp)->remove_all_cortex_a8_stubs();
12161     }
12162
12163   // Scan relocs for relocation stubs
12164   for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
12165        op != input_objects->relobj_end();
12166        ++op)
12167     {
12168       Arm_relobj<big_endian>* arm_relobj =
12169         Arm_relobj<big_endian>::as_arm_relobj(*op);
12170       // Lock the object so we can read from it.  This is only called
12171       // single-threaded from Layout::finalize, so it is OK to lock.
12172       Task_lock_obj<Object> tl(task, arm_relobj);
12173       arm_relobj->scan_sections_for_stubs(this, symtab, layout);
12174     }
12175
12176   // Check all stub tables to see if any of them have their data sizes
12177   // or addresses alignments changed.  These are the only things that
12178   // matter.
12179   bool any_stub_table_changed = false;
12180   Unordered_set<const Output_section*> sections_needing_adjustment;
12181   for (Stub_table_iterator sp = this->stub_tables_.begin();
12182        (sp != this->stub_tables_.end()) && !any_stub_table_changed;
12183        ++sp)
12184     {
12185       if ((*sp)->update_data_size_and_addralign())
12186         {
12187           // Update data size of stub table owner.
12188           Arm_input_section<big_endian>* owner = (*sp)->owner();
12189           uint64_t address = owner->address();
12190           off_t offset = owner->offset();
12191           owner->reset_address_and_file_offset();
12192           owner->set_address_and_file_offset(address, offset);
12193
12194           sections_needing_adjustment.insert(owner->output_section());
12195           any_stub_table_changed = true;
12196         }
12197     }
12198
12199   // Output_section_data::output_section() returns a const pointer but we
12200   // need to update output sections, so we record all output sections needing
12201   // update above and scan the sections here to find out what sections need
12202   // to be updated.
12203   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
12204       p != layout->section_list().end();
12205       ++p)
12206     {
12207       if (sections_needing_adjustment.find(*p)
12208           != sections_needing_adjustment.end())
12209         (*p)->set_section_offsets_need_adjustment();
12210     }
12211
12212   // Stop relaxation if no EXIDX fix-up and no stub table change.
12213   bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
12214
12215   // Finalize the stubs in the last relaxation pass.
12216   if (!continue_relaxation)
12217     {
12218       for (Stub_table_iterator sp = this->stub_tables_.begin();
12219            (sp != this->stub_tables_.end()) && !any_stub_table_changed;
12220             ++sp)
12221         (*sp)->finalize_stubs();
12222
12223       // Update output local symbol counts of objects if necessary.
12224       for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
12225            op != input_objects->relobj_end();
12226            ++op)
12227         {
12228           Arm_relobj<big_endian>* arm_relobj =
12229             Arm_relobj<big_endian>::as_arm_relobj(*op);
12230
12231           // Update output local symbol counts.  We need to discard local
12232           // symbols defined in parts of input sections that are discarded by
12233           // relaxation.
12234           if (arm_relobj->output_local_symbol_count_needs_update())
12235             {
12236               // We need to lock the object's file to update it.
12237               Task_lock_obj<Object> tl(task, arm_relobj);
12238               arm_relobj->update_output_local_symbol_count();
12239             }
12240         }
12241     }
12242
12243   return continue_relaxation;
12244 }
12245
12246 // Relocate a stub.
12247
12248 template<bool big_endian>
12249 void
12250 Target_arm<big_endian>::relocate_stub(
12251     Stub* stub,
12252     const Relocate_info<32, big_endian>* relinfo,
12253     Output_section* output_section,
12254     unsigned char* view,
12255     Arm_address address,
12256     section_size_type view_size)
12257 {
12258   Relocate relocate;
12259   const Stub_template* stub_template = stub->stub_template();
12260   for (size_t i = 0; i < stub_template->reloc_count(); i++)
12261     {
12262       size_t reloc_insn_index = stub_template->reloc_insn_index(i);
12263       const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
12264
12265       unsigned int r_type = insn->r_type();
12266       section_size_type reloc_offset = stub_template->reloc_offset(i);
12267       section_size_type reloc_size = insn->size();
12268       gold_assert(reloc_offset + reloc_size <= view_size);
12269
12270       // This is the address of the stub destination.
12271       Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
12272       Symbol_value<32> symval;
12273       symval.set_output_value(target);
12274
12275       // Synthesize a fake reloc just in case.  We don't have a symbol so
12276       // we use 0.
12277       unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
12278       memset(reloc_buffer, 0, sizeof(reloc_buffer));
12279       elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
12280       reloc_write.put_r_offset(reloc_offset);
12281       reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
12282       elfcpp::Rel<32, big_endian> rel(reloc_buffer);
12283
12284       relocate.relocate(relinfo, this, output_section,
12285                         this->fake_relnum_for_stubs, rel, r_type,
12286                         NULL, &symval, view + reloc_offset,
12287                         address + reloc_offset, reloc_size);
12288     }
12289 }
12290
12291 // Determine whether an object attribute tag takes an integer, a
12292 // string or both.
12293
12294 template<bool big_endian>
12295 int
12296 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
12297 {
12298   if (tag == Object_attribute::Tag_compatibility)
12299     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
12300             | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
12301   else if (tag == elfcpp::Tag_nodefaults)
12302     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
12303             | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
12304   else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
12305     return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
12306   else if (tag < 32)
12307     return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
12308   else
12309     return ((tag & 1) != 0
12310             ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
12311             : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
12312 }
12313
12314 // Reorder attributes.
12315 //
12316 // The ABI defines that Tag_conformance should be emitted first, and that
12317 // Tag_nodefaults should be second (if either is defined).  This sets those
12318 // two positions, and bumps up the position of all the remaining tags to
12319 // compensate.
12320
12321 template<bool big_endian>
12322 int
12323 Target_arm<big_endian>::do_attributes_order(int num) const
12324 {
12325   // Reorder the known object attributes in output.  We want to move
12326   // Tag_conformance to position 4 and Tag_conformance to position 5
12327   // and shift everything between 4 .. Tag_conformance - 1 to make room.
12328   if (num == 4)
12329     return elfcpp::Tag_conformance;
12330   if (num == 5)
12331     return elfcpp::Tag_nodefaults;
12332   if ((num - 2) < elfcpp::Tag_nodefaults)
12333     return num - 2;
12334   if ((num - 1) < elfcpp::Tag_conformance)
12335     return num - 1;
12336   return num;
12337 }
12338
12339 // Scan a span of THUMB code for Cortex-A8 erratum.
12340
12341 template<bool big_endian>
12342 void
12343 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
12344     Arm_relobj<big_endian>* arm_relobj,
12345     unsigned int shndx,
12346     section_size_type span_start,
12347     section_size_type span_end,
12348     const unsigned char* view,
12349     Arm_address address)
12350 {
12351   // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
12352   //
12353   // The opcode is BLX.W, BL.W, B.W, Bcc.W
12354   // The branch target is in the same 4KB region as the
12355   // first half of the branch.
12356   // The instruction before the branch is a 32-bit
12357   // length non-branch instruction.
12358   section_size_type i = span_start;
12359   bool last_was_32bit = false;
12360   bool last_was_branch = false;
12361   while (i < span_end)
12362     {
12363       typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
12364       const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
12365       uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
12366       bool is_blx = false, is_b = false;
12367       bool is_bl = false, is_bcc = false;
12368
12369       bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
12370       if (insn_32bit)
12371         {
12372           // Load the rest of the insn (in manual-friendly order).
12373           insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
12374
12375           // Encoding T4: B<c>.W.
12376           is_b = (insn & 0xf800d000U) == 0xf0009000U;
12377           // Encoding T1: BL<c>.W.
12378           is_bl = (insn & 0xf800d000U) == 0xf000d000U;
12379           // Encoding T2: BLX<c>.W.
12380           is_blx = (insn & 0xf800d000U) == 0xf000c000U;
12381           // Encoding T3: B<c>.W (not permitted in IT block).
12382           is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
12383                     && (insn & 0x07f00000U) != 0x03800000U);
12384         }
12385
12386       bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
12387
12388       // If this instruction is a 32-bit THUMB branch that crosses a 4K
12389       // page boundary and it follows 32-bit non-branch instruction,
12390       // we need to work around.
12391       if (is_32bit_branch
12392           && ((address + i) & 0xfffU) == 0xffeU
12393           && last_was_32bit
12394           && !last_was_branch)
12395         {
12396           // Check to see if there is a relocation stub for this branch.
12397           bool force_target_arm = false;
12398           bool force_target_thumb = false;
12399           const Cortex_a8_reloc* cortex_a8_reloc = NULL;
12400           Cortex_a8_relocs_info::const_iterator p =
12401             this->cortex_a8_relocs_info_.find(address + i);
12402
12403           if (p != this->cortex_a8_relocs_info_.end())
12404             {
12405               cortex_a8_reloc = p->second;
12406               bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
12407
12408               if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
12409                   && !target_is_thumb)
12410                 force_target_arm = true;
12411               else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
12412                        && target_is_thumb)
12413                 force_target_thumb = true;
12414             }
12415
12416           off_t offset;
12417           Stub_type stub_type = arm_stub_none;
12418
12419           // Check if we have an offending branch instruction.
12420           uint16_t upper_insn = (insn >> 16) & 0xffffU;
12421           uint16_t lower_insn = insn & 0xffffU;
12422           typedef class Arm_relocate_functions<big_endian> RelocFuncs;
12423
12424           if (cortex_a8_reloc != NULL
12425               && cortex_a8_reloc->reloc_stub() != NULL)
12426             // We've already made a stub for this instruction, e.g.
12427             // it's a long branch or a Thumb->ARM stub.  Assume that
12428             // stub will suffice to work around the A8 erratum (see
12429             // setting of always_after_branch above).
12430             ;
12431           else if (is_bcc)
12432             {
12433               offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
12434                                                               lower_insn);
12435               stub_type = arm_stub_a8_veneer_b_cond;
12436             }
12437           else if (is_b || is_bl || is_blx)
12438             {
12439               offset = RelocFuncs::thumb32_branch_offset(upper_insn,
12440                                                          lower_insn);
12441               if (is_blx)
12442                 offset &= ~3;
12443
12444               stub_type = (is_blx
12445                            ? arm_stub_a8_veneer_blx
12446                            : (is_bl
12447                               ? arm_stub_a8_veneer_bl
12448                               : arm_stub_a8_veneer_b));
12449             }
12450
12451           if (stub_type != arm_stub_none)
12452             {
12453               Arm_address pc_for_insn = address + i + 4;
12454
12455               // The original instruction is a BL, but the target is
12456               // an ARM instruction.  If we were not making a stub,
12457               // the BL would have been converted to a BLX.  Use the
12458               // BLX stub instead in that case.
12459               if (this->may_use_v5t_interworking() && force_target_arm
12460                   && stub_type == arm_stub_a8_veneer_bl)
12461                 {
12462                   stub_type = arm_stub_a8_veneer_blx;
12463                   is_blx = true;
12464                   is_bl = false;
12465                 }
12466               // Conversely, if the original instruction was
12467               // BLX but the target is Thumb mode, use the BL stub.
12468               else if (force_target_thumb
12469                        && stub_type == arm_stub_a8_veneer_blx)
12470                 {
12471                   stub_type = arm_stub_a8_veneer_bl;
12472                   is_blx = false;
12473                   is_bl = true;
12474                 }
12475
12476               if (is_blx)
12477                 pc_for_insn &= ~3;
12478
12479               // If we found a relocation, use the proper destination,
12480               // not the offset in the (unrelocated) instruction.
12481               // Note this is always done if we switched the stub type above.
12482               if (cortex_a8_reloc != NULL)
12483                 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
12484
12485               Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
12486
12487               // Add a new stub if destination address in in the same page.
12488               if (((address + i) & ~0xfffU) == (target & ~0xfffU))
12489                 {
12490                   Cortex_a8_stub* stub =
12491                     this->stub_factory_.make_cortex_a8_stub(stub_type,
12492                                                             arm_relobj, shndx,
12493                                                             address + i,
12494                                                             target, insn);
12495                   Stub_table<big_endian>* stub_table =
12496                     arm_relobj->stub_table(shndx);
12497                   gold_assert(stub_table != NULL);
12498                   stub_table->add_cortex_a8_stub(address + i, stub);
12499                 }
12500             }
12501         }
12502
12503       i += insn_32bit ? 4 : 2;
12504       last_was_32bit = insn_32bit;
12505       last_was_branch = is_32bit_branch;
12506     }
12507 }
12508
12509 // Apply the Cortex-A8 workaround.
12510
12511 template<bool big_endian>
12512 void
12513 Target_arm<big_endian>::apply_cortex_a8_workaround(
12514     const Cortex_a8_stub* stub,
12515     Arm_address stub_address,
12516     unsigned char* insn_view,
12517     Arm_address insn_address)
12518 {
12519   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
12520   Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
12521   Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
12522   Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
12523   off_t branch_offset = stub_address - (insn_address + 4);
12524
12525   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
12526   switch (stub->stub_template()->type())
12527     {
12528     case arm_stub_a8_veneer_b_cond:
12529       // For a conditional branch, we re-write it to be an unconditional
12530       // branch to the stub.  We use the THUMB-2 encoding here.
12531       upper_insn = 0xf000U;
12532       lower_insn = 0xb800U;
12533       // Fall through
12534     case arm_stub_a8_veneer_b:
12535     case arm_stub_a8_veneer_bl:
12536     case arm_stub_a8_veneer_blx:
12537       if ((lower_insn & 0x5000U) == 0x4000U)
12538         // For a BLX instruction, make sure that the relocation is
12539         // rounded up to a word boundary.  This follows the semantics of
12540         // the instruction which specifies that bit 1 of the target
12541         // address will come from bit 1 of the base address.
12542         branch_offset = (branch_offset + 2) & ~3;
12543
12544       // Put BRANCH_OFFSET back into the insn.
12545       gold_assert(!Bits<25>::has_overflow32(branch_offset));
12546       upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
12547       lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
12548       break;
12549
12550     default:
12551       gold_unreachable();
12552     }
12553
12554   // Put the relocated value back in the object file:
12555   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
12556   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
12557 }
12558
12559 // Target selector for ARM.  Note this is never instantiated directly.
12560 // It's only used in Target_selector_arm_nacl, below.
12561
12562 template<bool big_endian>
12563 class Target_selector_arm : public Target_selector
12564 {
12565  public:
12566   Target_selector_arm()
12567     : Target_selector(elfcpp::EM_ARM, 32, big_endian,
12568                       (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
12569                       (big_endian ? "armelfb" : "armelf"))
12570   { }
12571
12572   Target*
12573   do_instantiate_target()
12574   { return new Target_arm<big_endian>(); }
12575 };
12576
12577 // Fix .ARM.exidx section coverage.
12578
12579 template<bool big_endian>
12580 void
12581 Target_arm<big_endian>::fix_exidx_coverage(
12582     Layout* layout,
12583     const Input_objects* input_objects,
12584     Arm_output_section<big_endian>* exidx_section,
12585     Symbol_table* symtab,
12586     const Task* task)
12587 {
12588   // We need to look at all the input sections in output in ascending
12589   // order of of output address.  We do that by building a sorted list
12590   // of output sections by addresses.  Then we looks at the output sections
12591   // in order.  The input sections in an output section are already sorted
12592   // by addresses within the output section.
12593
12594   typedef std::set<Output_section*, output_section_address_less_than>
12595       Sorted_output_section_list;
12596   Sorted_output_section_list sorted_output_sections;
12597
12598   // Find out all the output sections of input sections pointed by
12599   // EXIDX input sections.
12600   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
12601        p != input_objects->relobj_end();
12602        ++p)
12603     {
12604       Arm_relobj<big_endian>* arm_relobj =
12605         Arm_relobj<big_endian>::as_arm_relobj(*p);
12606       std::vector<unsigned int> shndx_list;
12607       arm_relobj->get_exidx_shndx_list(&shndx_list);
12608       for (size_t i = 0; i < shndx_list.size(); ++i)
12609         {
12610           const Arm_exidx_input_section* exidx_input_section =
12611             arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
12612           gold_assert(exidx_input_section != NULL);
12613           if (!exidx_input_section->has_errors())
12614             {
12615               unsigned int text_shndx = exidx_input_section->link();
12616               Output_section* os = arm_relobj->output_section(text_shndx);
12617               if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
12618                 sorted_output_sections.insert(os);
12619             }
12620         }
12621     }
12622
12623   // Go over the output sections in ascending order of output addresses.
12624   typedef typename Arm_output_section<big_endian>::Text_section_list
12625       Text_section_list;
12626   Text_section_list sorted_text_sections;
12627   for (typename Sorted_output_section_list::iterator p =
12628         sorted_output_sections.begin();
12629       p != sorted_output_sections.end();
12630       ++p)
12631     {
12632       Arm_output_section<big_endian>* arm_output_section =
12633         Arm_output_section<big_endian>::as_arm_output_section(*p);
12634       arm_output_section->append_text_sections_to_list(&sorted_text_sections);
12635     }
12636
12637   exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
12638                                     merge_exidx_entries(), task);
12639 }
12640
12641 template<bool big_endian>
12642 void
12643 Target_arm<big_endian>::do_define_standard_symbols(
12644     Symbol_table* symtab,
12645     Layout* layout)
12646 {
12647   // Handle the .ARM.exidx section.
12648   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
12649
12650   if (exidx_section != NULL)
12651     {
12652       // Create __exidx_start and __exidx_end symbols.
12653       symtab->define_in_output_data("__exidx_start",
12654                                     NULL, // version
12655                                     Symbol_table::PREDEFINED,
12656                                     exidx_section,
12657                                     0, // value
12658                                     0, // symsize
12659                                     elfcpp::STT_NOTYPE,
12660                                     elfcpp::STB_GLOBAL,
12661                                     elfcpp::STV_HIDDEN,
12662                                     0, // nonvis
12663                                     false, // offset_is_from_end
12664                                     true); // only_if_ref
12665
12666       symtab->define_in_output_data("__exidx_end",
12667                                     NULL, // version
12668                                     Symbol_table::PREDEFINED,
12669                                     exidx_section,
12670                                     0, // value
12671                                     0, // symsize
12672                                     elfcpp::STT_NOTYPE,
12673                                     elfcpp::STB_GLOBAL,
12674                                     elfcpp::STV_HIDDEN,
12675                                     0, // nonvis
12676                                     true, // offset_is_from_end
12677                                     true); // only_if_ref
12678     }
12679   else
12680     {
12681       // Define __exidx_start and __exidx_end even when .ARM.exidx
12682       // section is missing to match ld's behaviour.
12683       symtab->define_as_constant("__exidx_start", NULL,
12684                                  Symbol_table::PREDEFINED,
12685                                  0, 0, elfcpp::STT_OBJECT,
12686                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12687                                  true, false);
12688       symtab->define_as_constant("__exidx_end", NULL,
12689                                  Symbol_table::PREDEFINED,
12690                                  0, 0, elfcpp::STT_OBJECT,
12691                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12692                                  true, false);
12693     }
12694 }
12695
12696 // NaCl variant.  It uses different PLT contents.
12697
12698 template<bool big_endian>
12699 class Output_data_plt_arm_nacl;
12700
12701 template<bool big_endian>
12702 class Target_arm_nacl : public Target_arm<big_endian>
12703 {
12704  public:
12705   Target_arm_nacl()
12706     : Target_arm<big_endian>(&arm_nacl_info)
12707   { }
12708
12709  protected:
12710   virtual Output_data_plt_arm<big_endian>*
12711   do_make_data_plt(
12712                    Layout* layout,
12713                    Arm_output_data_got<big_endian>* got,
12714                    Output_data_space* got_plt,
12715                    Output_data_space* got_irelative)
12716   { return new Output_data_plt_arm_nacl<big_endian>(
12717       layout, got, got_plt, got_irelative); }
12718
12719  private:
12720   static const Target::Target_info arm_nacl_info;
12721 };
12722
12723 template<bool big_endian>
12724 const Target::Target_info Target_arm_nacl<big_endian>::arm_nacl_info =
12725 {
12726   32,                   // size
12727   big_endian,           // is_big_endian
12728   elfcpp::EM_ARM,       // machine_code
12729   false,                // has_make_symbol
12730   false,                // has_resolve
12731   false,                // has_code_fill
12732   true,                 // is_default_stack_executable
12733   false,                // can_icf_inline_merge_sections
12734   '\0',                 // wrap_char
12735   "/lib/ld-nacl-arm.so.1", // dynamic_linker
12736   0x20000,              // default_text_segment_address
12737   0x10000,              // abi_pagesize (overridable by -z max-page-size)
12738   0x10000,              // common_pagesize (overridable by -z common-page-size)
12739   true,                 // isolate_execinstr
12740   0x10000000,           // rosegment_gap
12741   elfcpp::SHN_UNDEF,    // small_common_shndx
12742   elfcpp::SHN_UNDEF,    // large_common_shndx
12743   0,                    // small_common_section_flags
12744   0,                    // large_common_section_flags
12745   ".ARM.attributes",    // attributes_section
12746   "aeabi",              // attributes_vendor
12747   "_start"              // entry_symbol_name
12748 };
12749
12750 template<bool big_endian>
12751 class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
12752 {
12753  public:
12754   Output_data_plt_arm_nacl(
12755       Layout* layout,
12756       Arm_output_data_got<big_endian>* got,
12757       Output_data_space* got_plt,
12758       Output_data_space* got_irelative)
12759     : Output_data_plt_arm<big_endian>(layout, 16, got, got_plt, got_irelative)
12760   { }
12761
12762  protected:
12763   // Return the offset of the first non-reserved PLT entry.
12764   virtual unsigned int
12765   do_first_plt_entry_offset() const
12766   { return sizeof(first_plt_entry); }
12767
12768   // Return the size of a PLT entry.
12769   virtual unsigned int
12770   do_get_plt_entry_size() const
12771   { return sizeof(plt_entry); }
12772
12773   virtual void
12774   do_fill_first_plt_entry(unsigned char* pov,
12775                           Arm_address got_address,
12776                           Arm_address plt_address);
12777
12778   virtual void
12779   do_fill_plt_entry(unsigned char* pov,
12780                     Arm_address got_address,
12781                     Arm_address plt_address,
12782                     unsigned int got_offset,
12783                     unsigned int plt_offset);
12784
12785  private:
12786   inline uint32_t arm_movw_immediate(uint32_t value)
12787   {
12788     return (value & 0x00000fff) | ((value & 0x0000f000) << 4);
12789   }
12790
12791   inline uint32_t arm_movt_immediate(uint32_t value)
12792   {
12793     return ((value & 0x0fff0000) >> 16) | ((value & 0xf0000000) >> 12);
12794   }
12795
12796   // Template for the first PLT entry.
12797   static const uint32_t first_plt_entry[16];
12798
12799   // Template for subsequent PLT entries.
12800   static const uint32_t plt_entry[4];
12801 };
12802
12803 // The first entry in the PLT.
12804 template<bool big_endian>
12805 const uint32_t Output_data_plt_arm_nacl<big_endian>::first_plt_entry[16] =
12806 {
12807   // First bundle:
12808   0xe300c000,                           // movw ip, #:lower16:&GOT[2]-.+8
12809   0xe340c000,                           // movt ip, #:upper16:&GOT[2]-.+8
12810   0xe08cc00f,                           // add  ip, ip, pc
12811   0xe52dc008,                           // str  ip, [sp, #-8]!
12812   // Second bundle:
12813   0xe3ccc103,                           // bic  ip, ip, #0xc0000000
12814   0xe59cc000,                           // ldr  ip, [ip]
12815   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
12816   0xe12fff1c,                           // bx   ip
12817   // Third bundle:
12818   0xe320f000,                           // nop
12819   0xe320f000,                           // nop
12820   0xe320f000,                           // nop
12821   // .Lplt_tail:
12822   0xe50dc004,                           // str  ip, [sp, #-4]
12823   // Fourth bundle:
12824   0xe3ccc103,                           // bic  ip, ip, #0xc0000000
12825   0xe59cc000,                           // ldr  ip, [ip]
12826   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
12827   0xe12fff1c,                           // bx   ip
12828 };
12829
12830 template<bool big_endian>
12831 void
12832 Output_data_plt_arm_nacl<big_endian>::do_fill_first_plt_entry(
12833     unsigned char* pov,
12834     Arm_address got_address,
12835     Arm_address plt_address)
12836 {
12837   // Write first PLT entry.  All but first two words are constants.
12838   const size_t num_first_plt_words = (sizeof(first_plt_entry)
12839                                       / sizeof(first_plt_entry[0]));
12840
12841   int32_t got_displacement = got_address + 8 - (plt_address + 16);
12842
12843   elfcpp::Swap<32, big_endian>::writeval
12844     (pov + 0, first_plt_entry[0] | arm_movw_immediate (got_displacement));
12845   elfcpp::Swap<32, big_endian>::writeval
12846     (pov + 4, first_plt_entry[1] | arm_movt_immediate (got_displacement));
12847
12848   for (size_t i = 2; i < num_first_plt_words; ++i)
12849     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
12850 }
12851
12852 // Subsequent entries in the PLT.
12853
12854 template<bool big_endian>
12855 const uint32_t Output_data_plt_arm_nacl<big_endian>::plt_entry[4] =
12856 {
12857   0xe300c000,                           // movw ip, #:lower16:&GOT[n]-.+8
12858   0xe340c000,                           // movt ip, #:upper16:&GOT[n]-.+8
12859   0xe08cc00f,                           // add  ip, ip, pc
12860   0xea000000,                           // b    .Lplt_tail
12861 };
12862
12863 template<bool big_endian>
12864 void
12865 Output_data_plt_arm_nacl<big_endian>::do_fill_plt_entry(
12866     unsigned char* pov,
12867     Arm_address got_address,
12868     Arm_address plt_address,
12869     unsigned int got_offset,
12870     unsigned int plt_offset)
12871 {
12872   // Calculate the displacement between the PLT slot and the
12873   // common tail that's part of the special initial PLT slot.
12874   int32_t tail_displacement = (plt_address + (11 * sizeof(uint32_t))
12875                                - (plt_address + plt_offset
12876                                   + sizeof(plt_entry) + sizeof(uint32_t)));
12877   gold_assert((tail_displacement & 3) == 0);
12878   tail_displacement >>= 2;
12879
12880   gold_assert ((tail_displacement & 0xff000000) == 0
12881                || (-tail_displacement & 0xff000000) == 0);
12882
12883   // Calculate the displacement between the PLT slot and the entry
12884   // in the GOT.  The offset accounts for the value produced by
12885   // adding to pc in the penultimate instruction of the PLT stub.
12886   const int32_t got_displacement = (got_address + got_offset
12887                                     - (plt_address + sizeof(plt_entry)));
12888
12889   elfcpp::Swap<32, big_endian>::writeval
12890     (pov + 0, plt_entry[0] | arm_movw_immediate (got_displacement));
12891   elfcpp::Swap<32, big_endian>::writeval
12892     (pov + 4, plt_entry[1] | arm_movt_immediate (got_displacement));
12893   elfcpp::Swap<32, big_endian>::writeval
12894     (pov + 8, plt_entry[2]);
12895   elfcpp::Swap<32, big_endian>::writeval
12896     (pov + 12, plt_entry[3] | (tail_displacement & 0x00ffffff));
12897 }
12898
12899 // Target selectors.
12900
12901 template<bool big_endian>
12902 class Target_selector_arm_nacl
12903   : public Target_selector_nacl<Target_selector_arm<big_endian>,
12904                                 Target_arm_nacl<big_endian> >
12905 {
12906  public:
12907   Target_selector_arm_nacl()
12908     : Target_selector_nacl<Target_selector_arm<big_endian>,
12909                            Target_arm_nacl<big_endian> >(
12910           "arm",
12911           big_endian ? "elf32-bigarm-nacl" : "elf32-littlearm-nacl",
12912           big_endian ? "armelfb_nacl" : "armelf_nacl")
12913   { }
12914 };
12915
12916 Target_selector_arm_nacl<false> target_selector_arm;
12917 Target_selector_arm_nacl<true> target_selector_armbe;
12918
12919 } // End anonymous namespace.