Remove unnecessary target dependencies on relocation format.
[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     unsigned int r_type = elfcpp::elf_r_type<32>(reloc.get_r_info());
2810     this->copy_relocs_.copy_reloc(symtab, layout,
2811                                   symtab->get_sized_symbol<32>(sym),
2812                                   object, shndx, output_section,
2813                                   r_type, reloc.get_r_offset(), 0,
2814                                   this->rel_dyn_section(layout));
2815   }
2816
2817   // Whether two EABI versions are compatible.
2818   static bool
2819   are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2820
2821   // Merge processor-specific flags from input object and those in the ELF
2822   // header of the output.
2823   void
2824   merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2825
2826   // Get the secondary compatible architecture.
2827   static int
2828   get_secondary_compatible_arch(const Attributes_section_data*);
2829
2830   // Set the secondary compatible architecture.
2831   static void
2832   set_secondary_compatible_arch(Attributes_section_data*, int);
2833
2834   static int
2835   tag_cpu_arch_combine(const char*, int, int*, int, int);
2836
2837   // Helper to print AEABI enum tag value.
2838   static std::string
2839   aeabi_enum_name(unsigned int);
2840
2841   // Return string value for TAG_CPU_name.
2842   static std::string
2843   tag_cpu_name_value(unsigned int);
2844
2845   // Query attributes object to see if integer divide instructions may be
2846   // present in an object.
2847   static bool
2848   attributes_accept_div(int arch, int profile,
2849                         const Object_attribute* div_attr);
2850
2851   // Query attributes object to see if integer divide instructions are
2852   // forbidden to be in the object.  This is not the inverse of
2853   // attributes_accept_div.
2854   static bool
2855   attributes_forbid_div(const Object_attribute* div_attr);
2856
2857   // Merge object attributes from input object and those in the output.
2858   void
2859   merge_object_attributes(const char*, const Attributes_section_data*);
2860
2861   // Helper to get an AEABI object attribute
2862   Object_attribute*
2863   get_aeabi_object_attribute(int tag) const
2864   {
2865     Attributes_section_data* pasd = this->attributes_section_data_;
2866     gold_assert(pasd != NULL);
2867     Object_attribute* attr =
2868       pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2869     gold_assert(attr != NULL);
2870     return attr;
2871   }
2872
2873   //
2874   // Methods to support stub-generations.
2875   //
2876
2877   // Group input sections for stub generation.
2878   void
2879   group_sections(Layout*, section_size_type, bool, const Task*);
2880
2881   // Scan a relocation for stub generation.
2882   void
2883   scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2884                       const Sized_symbol<32>*, unsigned int,
2885                       const Symbol_value<32>*,
2886                       elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2887
2888   // Scan a relocation section for stub.
2889   template<int sh_type>
2890   void
2891   scan_reloc_section_for_stubs(
2892       const Relocate_info<32, big_endian>* relinfo,
2893       const unsigned char* prelocs,
2894       size_t reloc_count,
2895       Output_section* output_section,
2896       bool needs_special_offset_handling,
2897       const unsigned char* view,
2898       elfcpp::Elf_types<32>::Elf_Addr view_address,
2899       section_size_type);
2900
2901   // Fix .ARM.exidx section coverage.
2902   void
2903   fix_exidx_coverage(Layout*, const Input_objects*,
2904                      Arm_output_section<big_endian>*, Symbol_table*,
2905                      const Task*);
2906
2907   // Functors for STL set.
2908   struct output_section_address_less_than
2909   {
2910     bool
2911     operator()(const Output_section* s1, const Output_section* s2) const
2912     { return s1->address() < s2->address(); }
2913   };
2914
2915   // Information about this specific target which we pass to the
2916   // general Target structure.
2917   static const Target::Target_info arm_info;
2918
2919   // The types of GOT entries needed for this platform.
2920   // These values are exposed to the ABI in an incremental link.
2921   // Do not renumber existing values without changing the version
2922   // number of the .gnu_incremental_inputs section.
2923   enum Got_type
2924   {
2925     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
2926     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
2927     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
2928     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
2929     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
2930   };
2931
2932   typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2933
2934   // Map input section to Arm_input_section.
2935   typedef Unordered_map<Section_id,
2936                         Arm_input_section<big_endian>*,
2937                         Section_id_hash>
2938           Arm_input_section_map;
2939
2940   // Map output addresses to relocs for Cortex-A8 erratum.
2941   typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2942           Cortex_a8_relocs_info;
2943
2944   // The GOT section.
2945   Arm_output_data_got<big_endian>* got_;
2946   // The PLT section.
2947   Output_data_plt_arm<big_endian>* plt_;
2948   // The GOT PLT section.
2949   Output_data_space* got_plt_;
2950   // The GOT section for IRELATIVE relocations.
2951   Output_data_space* got_irelative_;
2952   // The dynamic reloc section.
2953   Reloc_section* rel_dyn_;
2954   // The section to use for IRELATIVE relocs.
2955   Reloc_section* rel_irelative_;
2956   // Relocs saved to avoid a COPY reloc.
2957   Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2958   // Offset of the GOT entry for the TLS module index.
2959   unsigned int got_mod_index_offset_;
2960   // True if the _TLS_MODULE_BASE_ symbol has been defined.
2961   bool tls_base_symbol_defined_;
2962   // Vector of Stub_tables created.
2963   Stub_table_list stub_tables_;
2964   // Stub factory.
2965   const Stub_factory &stub_factory_;
2966   // Whether we force PIC branch veneers.
2967   bool should_force_pic_veneer_;
2968   // Map for locating Arm_input_sections.
2969   Arm_input_section_map arm_input_section_map_;
2970   // Attributes section data in output.
2971   Attributes_section_data* attributes_section_data_;
2972   // Whether we want to fix code for Cortex-A8 erratum.
2973   bool fix_cortex_a8_;
2974   // Map addresses to relocs for Cortex-A8 erratum.
2975   Cortex_a8_relocs_info cortex_a8_relocs_info_;
2976 };
2977
2978 template<bool big_endian>
2979 const Target::Target_info Target_arm<big_endian>::arm_info =
2980 {
2981   32,                   // size
2982   big_endian,           // is_big_endian
2983   elfcpp::EM_ARM,       // machine_code
2984   false,                // has_make_symbol
2985   false,                // has_resolve
2986   false,                // has_code_fill
2987   true,                 // is_default_stack_executable
2988   false,                // can_icf_inline_merge_sections
2989   '\0',                 // wrap_char
2990   "/usr/lib/libc.so.1", // dynamic_linker
2991   0x8000,               // default_text_segment_address
2992   0x1000,               // abi_pagesize (overridable by -z max-page-size)
2993   0x1000,               // common_pagesize (overridable by -z common-page-size)
2994   false,                // isolate_execinstr
2995   0,                    // rosegment_gap
2996   elfcpp::SHN_UNDEF,    // small_common_shndx
2997   elfcpp::SHN_UNDEF,    // large_common_shndx
2998   0,                    // small_common_section_flags
2999   0,                    // large_common_section_flags
3000   ".ARM.attributes",    // attributes_section
3001   "aeabi",              // attributes_vendor
3002   "_start",             // entry_symbol_name
3003   32,                   // hash_entry_size
3004 };
3005
3006 // Arm relocate functions class
3007 //
3008
3009 template<bool big_endian>
3010 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
3011 {
3012  public:
3013   typedef enum
3014   {
3015     STATUS_OKAY,        // No error during relocation.
3016     STATUS_OVERFLOW,    // Relocation overflow.
3017     STATUS_BAD_RELOC    // Relocation cannot be applied.
3018   } Status;
3019
3020  private:
3021   typedef Relocate_functions<32, big_endian> Base;
3022   typedef Arm_relocate_functions<big_endian> This;
3023
3024   // Encoding of imm16 argument for movt and movw ARM instructions
3025   // from ARM ARM:
3026   //
3027   //     imm16 := imm4 | imm12
3028   //
3029   //  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
3030   // +-------+---------------+-------+-------+-----------------------+
3031   // |       |               |imm4   |       |imm12                  |
3032   // +-------+---------------+-------+-------+-----------------------+
3033
3034   // Extract the relocation addend from VAL based on the ARM
3035   // instruction encoding described above.
3036   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3037   extract_arm_movw_movt_addend(
3038       typename elfcpp::Swap<32, big_endian>::Valtype val)
3039   {
3040     // According to the Elf ABI for ARM Architecture the immediate
3041     // field is sign-extended to form the addend.
3042     return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff));
3043   }
3044
3045   // Insert X into VAL based on the ARM instruction encoding described
3046   // above.
3047   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3048   insert_val_arm_movw_movt(
3049       typename elfcpp::Swap<32, big_endian>::Valtype val,
3050       typename elfcpp::Swap<32, big_endian>::Valtype x)
3051   {
3052     val &= 0xfff0f000;
3053     val |= x & 0x0fff;
3054     val |= (x & 0xf000) << 4;
3055     return val;
3056   }
3057
3058   // Encoding of imm16 argument for movt and movw Thumb2 instructions
3059   // from ARM ARM:
3060   //
3061   //     imm16 := imm4 | i | imm3 | imm8
3062   //
3063   //  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
3064   // +---------+-+-----------+-------++-+-----+-------+---------------+
3065   // |         |i|           |imm4   || |imm3 |       |imm8           |
3066   // +---------+-+-----------+-------++-+-----+-------+---------------+
3067
3068   // Extract the relocation addend from VAL based on the Thumb2
3069   // instruction encoding described above.
3070   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3071   extract_thumb_movw_movt_addend(
3072       typename elfcpp::Swap<32, big_endian>::Valtype val)
3073   {
3074     // According to the Elf ABI for ARM Architecture the immediate
3075     // field is sign-extended to form the addend.
3076     return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
3077                                    | ((val >> 15) & 0x0800)
3078                                    | ((val >> 4) & 0x0700)
3079                                    | (val & 0x00ff));
3080   }
3081
3082   // Insert X into VAL based on the Thumb2 instruction encoding
3083   // described above.
3084   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3085   insert_val_thumb_movw_movt(
3086       typename elfcpp::Swap<32, big_endian>::Valtype val,
3087       typename elfcpp::Swap<32, big_endian>::Valtype x)
3088   {
3089     val &= 0xfbf08f00;
3090     val |= (x & 0xf000) << 4;
3091     val |= (x & 0x0800) << 15;
3092     val |= (x & 0x0700) << 4;
3093     val |= (x & 0x00ff);
3094     return val;
3095   }
3096
3097   // Calculate the smallest constant Kn for the specified residual.
3098   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3099   static uint32_t
3100   calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3101   {
3102     int32_t msb;
3103
3104     if (residual == 0)
3105       return 0;
3106     // Determine the most significant bit in the residual and
3107     // align the resulting value to a 2-bit boundary.
3108     for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3109       ;
3110     // The desired shift is now (msb - 6), or zero, whichever
3111     // is the greater.
3112     return (((msb - 6) < 0) ? 0 : (msb - 6));
3113   }
3114
3115   // Calculate the final residual for the specified group index.
3116   // If the passed group index is less than zero, the method will return
3117   // the value of the specified residual without any change.
3118   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3119   static typename elfcpp::Swap<32, big_endian>::Valtype
3120   calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3121                     const int group)
3122   {
3123     for (int n = 0; n <= group; n++)
3124       {
3125         // Calculate which part of the value to mask.
3126         uint32_t shift = calc_grp_kn(residual);
3127         // Calculate the residual for the next time around.
3128         residual &= ~(residual & (0xff << shift));
3129       }
3130
3131     return residual;
3132   }
3133
3134   // Calculate the value of Gn for the specified group index.
3135   // We return it in the form of an encoded constant-and-rotation.
3136   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3137   static typename elfcpp::Swap<32, big_endian>::Valtype
3138   calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3139               const int group)
3140   {
3141     typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3142     uint32_t shift = 0;
3143
3144     for (int n = 0; n <= group; n++)
3145       {
3146         // Calculate which part of the value to mask.
3147         shift = calc_grp_kn(residual);
3148         // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3149         gn = residual & (0xff << shift);
3150         // Calculate the residual for the next time around.
3151         residual &= ~gn;
3152       }
3153     // Return Gn in the form of an encoded constant-and-rotation.
3154     return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3155   }
3156
3157  public:
3158   // Handle ARM long branches.
3159   static typename This::Status
3160   arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3161                     unsigned char*, const Sized_symbol<32>*,
3162                     const Arm_relobj<big_endian>*, unsigned int,
3163                     const Symbol_value<32>*, Arm_address, Arm_address, bool);
3164
3165   // Handle THUMB long branches.
3166   static typename This::Status
3167   thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3168                       unsigned char*, const Sized_symbol<32>*,
3169                       const Arm_relobj<big_endian>*, unsigned int,
3170                       const Symbol_value<32>*, Arm_address, Arm_address, bool);
3171
3172
3173   // Return the branch offset of a 32-bit THUMB branch.
3174   static inline int32_t
3175   thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3176   {
3177     // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3178     // involving the J1 and J2 bits.
3179     uint32_t s = (upper_insn & (1U << 10)) >> 10;
3180     uint32_t upper = upper_insn & 0x3ffU;
3181     uint32_t lower = lower_insn & 0x7ffU;
3182     uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3183     uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3184     uint32_t i1 = j1 ^ s ? 0 : 1;
3185     uint32_t i2 = j2 ^ s ? 0 : 1;
3186
3187     return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3188                                    | (upper << 12) | (lower << 1));
3189   }
3190
3191   // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3192   // UPPER_INSN is the original upper instruction of the branch.  Caller is
3193   // responsible for overflow checking and BLX offset adjustment.
3194   static inline uint16_t
3195   thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3196   {
3197     uint32_t s = offset < 0 ? 1 : 0;
3198     uint32_t bits = static_cast<uint32_t>(offset);
3199     return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3200   }
3201
3202   // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3203   // LOWER_INSN is the original lower instruction of the branch.  Caller is
3204   // responsible for overflow checking and BLX offset adjustment.
3205   static inline uint16_t
3206   thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3207   {
3208     uint32_t s = offset < 0 ? 1 : 0;
3209     uint32_t bits = static_cast<uint32_t>(offset);
3210     return ((lower_insn & ~0x2fffU)
3211             | ((((bits >> 23) & 1) ^ !s) << 13)
3212             | ((((bits >> 22) & 1) ^ !s) << 11)
3213             | ((bits >> 1) & 0x7ffU));
3214   }
3215
3216   // Return the branch offset of a 32-bit THUMB conditional branch.
3217   static inline int32_t
3218   thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3219   {
3220     uint32_t s = (upper_insn & 0x0400U) >> 10;
3221     uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3222     uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3223     uint32_t lower = (lower_insn & 0x07ffU);
3224     uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3225
3226     return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3227   }
3228
3229   // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3230   // instruction.  UPPER_INSN is the original upper instruction of the branch.
3231   // Caller is responsible for overflow checking.
3232   static inline uint16_t
3233   thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3234   {
3235     uint32_t s = offset < 0 ? 1 : 0;
3236     uint32_t bits = static_cast<uint32_t>(offset);
3237     return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3238   }
3239
3240   // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3241   // instruction.  LOWER_INSN is the original lower instruction of the branch.
3242   // The caller is responsible for overflow checking.
3243   static inline uint16_t
3244   thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3245   {
3246     uint32_t bits = static_cast<uint32_t>(offset);
3247     uint32_t j2 = (bits & 0x00080000U) >> 19;
3248     uint32_t j1 = (bits & 0x00040000U) >> 18;
3249     uint32_t lo = (bits & 0x00000ffeU) >> 1;
3250
3251     return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3252   }
3253
3254   // R_ARM_ABS8: S + A
3255   static inline typename This::Status
3256   abs8(unsigned char* view,
3257        const Sized_relobj_file<32, big_endian>* object,
3258        const Symbol_value<32>* psymval)
3259   {
3260     typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3261     Valtype* wv = reinterpret_cast<Valtype*>(view);
3262     Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3263     int32_t addend = Bits<8>::sign_extend32(val);
3264     Arm_address x = psymval->value(object, addend);
3265     val = Bits<32>::bit_select32(val, x, 0xffU);
3266     elfcpp::Swap<8, big_endian>::writeval(wv, val);
3267
3268     // R_ARM_ABS8 permits signed or unsigned results.
3269     return (Bits<8>::has_signed_unsigned_overflow32(x)
3270             ? This::STATUS_OVERFLOW
3271             : This::STATUS_OKAY);
3272   }
3273
3274   // R_ARM_THM_ABS5: S + A
3275   static inline typename This::Status
3276   thm_abs5(unsigned char* view,
3277        const Sized_relobj_file<32, big_endian>* object,
3278        const Symbol_value<32>* psymval)
3279   {
3280     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3281     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3282     Valtype* wv = reinterpret_cast<Valtype*>(view);
3283     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3284     Reltype addend = (val & 0x7e0U) >> 6;
3285     Reltype x = psymval->value(object, addend);
3286     val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3287     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3288     return (Bits<5>::has_overflow32(x)
3289             ? This::STATUS_OVERFLOW
3290             : This::STATUS_OKAY);
3291   }
3292
3293   // R_ARM_ABS12: S + A
3294   static inline typename This::Status
3295   abs12(unsigned char* view,
3296         const Sized_relobj_file<32, big_endian>* object,
3297         const Symbol_value<32>* psymval)
3298   {
3299     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3300     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3301     Valtype* wv = reinterpret_cast<Valtype*>(view);
3302     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3303     Reltype addend = val & 0x0fffU;
3304     Reltype x = psymval->value(object, addend);
3305     val = Bits<32>::bit_select32(val, x, 0x0fffU);
3306     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3307     return (Bits<12>::has_overflow32(x)
3308             ? This::STATUS_OVERFLOW
3309             : This::STATUS_OKAY);
3310   }
3311
3312   // R_ARM_ABS16: S + A
3313   static inline typename This::Status
3314   abs16(unsigned char* view,
3315         const Sized_relobj_file<32, big_endian>* object,
3316         const Symbol_value<32>* psymval)
3317   {
3318     typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
3319     Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view);
3320     int32_t addend = Bits<16>::sign_extend32(val);
3321     Arm_address x = psymval->value(object, addend);
3322     val = Bits<32>::bit_select32(val, x, 0xffffU);
3323     elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val);
3324
3325     // R_ARM_ABS16 permits signed or unsigned results.
3326     return (Bits<16>::has_signed_unsigned_overflow32(x)
3327             ? This::STATUS_OVERFLOW
3328             : This::STATUS_OKAY);
3329   }
3330
3331   // R_ARM_ABS32: (S + A) | T
3332   static inline typename This::Status
3333   abs32(unsigned char* view,
3334         const Sized_relobj_file<32, big_endian>* object,
3335         const Symbol_value<32>* psymval,
3336         Arm_address thumb_bit)
3337   {
3338     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3339     Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3340     Valtype x = psymval->value(object, addend) | thumb_bit;
3341     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3342     return This::STATUS_OKAY;
3343   }
3344
3345   // R_ARM_REL32: (S + A) | T - P
3346   static inline typename This::Status
3347   rel32(unsigned char* view,
3348         const Sized_relobj_file<32, big_endian>* object,
3349         const Symbol_value<32>* psymval,
3350         Arm_address address,
3351         Arm_address thumb_bit)
3352   {
3353     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3354     Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3355     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3356     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3357     return This::STATUS_OKAY;
3358   }
3359
3360   // R_ARM_THM_JUMP24: (S + A) | T - P
3361   static typename This::Status
3362   thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3363              const Symbol_value<32>* psymval, Arm_address address,
3364              Arm_address thumb_bit);
3365
3366   // R_ARM_THM_JUMP6: S + A â€“ P
3367   static inline typename This::Status
3368   thm_jump6(unsigned char* view,
3369             const Sized_relobj_file<32, big_endian>* object,
3370             const Symbol_value<32>* psymval,
3371             Arm_address address)
3372   {
3373     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3374     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3375     Valtype* wv = reinterpret_cast<Valtype*>(view);
3376     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3377     // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3378     Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3379     Reltype x = (psymval->value(object, addend) - address);
3380     val = (val & 0xfd07) | ((x  & 0x0040) << 3) | ((val & 0x003e) << 2);
3381     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3382     // CZB does only forward jumps.
3383     return ((x > 0x007e)
3384             ? This::STATUS_OVERFLOW
3385             : This::STATUS_OKAY);
3386   }
3387
3388   // R_ARM_THM_JUMP8: S + A â€“ P
3389   static inline typename This::Status
3390   thm_jump8(unsigned char* view,
3391             const Sized_relobj_file<32, big_endian>* object,
3392             const Symbol_value<32>* psymval,
3393             Arm_address address)
3394   {
3395     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3396     Valtype* wv = reinterpret_cast<Valtype*>(view);
3397     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3398     int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1);
3399     int32_t x = (psymval->value(object, addend) - address);
3400     elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00)
3401                                                 | ((x & 0x01fe) >> 1)));
3402     // We do a 9-bit overflow check because x is right-shifted by 1 bit.
3403     return (Bits<9>::has_overflow32(x)
3404             ? This::STATUS_OVERFLOW
3405             : This::STATUS_OKAY);
3406   }
3407
3408   // R_ARM_THM_JUMP11: S + A â€“ P
3409   static inline typename This::Status
3410   thm_jump11(unsigned char* view,
3411             const Sized_relobj_file<32, big_endian>* object,
3412             const Symbol_value<32>* psymval,
3413             Arm_address address)
3414   {
3415     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3416     Valtype* wv = reinterpret_cast<Valtype*>(view);
3417     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3418     int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1);
3419     int32_t x = (psymval->value(object, addend) - address);
3420     elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800)
3421                                                 | ((x & 0x0ffe) >> 1)));
3422     // We do a 12-bit overflow check because x is right-shifted by 1 bit.
3423     return (Bits<12>::has_overflow32(x)
3424             ? This::STATUS_OVERFLOW
3425             : This::STATUS_OKAY);
3426   }
3427
3428   // R_ARM_BASE_PREL: B(S) + A - P
3429   static inline typename This::Status
3430   base_prel(unsigned char* view,
3431             Arm_address origin,
3432             Arm_address address)
3433   {
3434     Base::rel32(view, origin - address);
3435     return STATUS_OKAY;
3436   }
3437
3438   // R_ARM_BASE_ABS: B(S) + A
3439   static inline typename This::Status
3440   base_abs(unsigned char* view,
3441            Arm_address origin)
3442   {
3443     Base::rel32(view, origin);
3444     return STATUS_OKAY;
3445   }
3446
3447   // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3448   static inline typename This::Status
3449   got_brel(unsigned char* view,
3450            typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3451   {
3452     Base::rel32(view, got_offset);
3453     return This::STATUS_OKAY;
3454   }
3455
3456   // R_ARM_GOT_PREL: GOT(S) + A - P
3457   static inline typename This::Status
3458   got_prel(unsigned char* view,
3459            Arm_address got_entry,
3460            Arm_address address)
3461   {
3462     Base::rel32(view, got_entry - address);
3463     return This::STATUS_OKAY;
3464   }
3465
3466   // R_ARM_PREL: (S + A) | T - P
3467   static inline typename This::Status
3468   prel31(unsigned char* view,
3469          const Sized_relobj_file<32, big_endian>* object,
3470          const Symbol_value<32>* psymval,
3471          Arm_address address,
3472          Arm_address thumb_bit)
3473   {
3474     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3475     Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3476     Valtype addend = Bits<31>::sign_extend32(val);
3477     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3478     val = Bits<32>::bit_select32(val, x, 0x7fffffffU);
3479     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val);
3480     return (Bits<31>::has_overflow32(x)
3481             ? This::STATUS_OVERFLOW
3482             : This::STATUS_OKAY);
3483   }
3484
3485   // R_ARM_MOVW_ABS_NC: (S + A) | T     (relative address base is )
3486   // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3487   // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3488   // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3489   static inline typename This::Status
3490   movw(unsigned char* view,
3491        const Sized_relobj_file<32, big_endian>* object,
3492        const Symbol_value<32>* psymval,
3493        Arm_address relative_address_base,
3494        Arm_address thumb_bit,
3495        bool check_overflow)
3496   {
3497     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3498     Valtype* wv = reinterpret_cast<Valtype*>(view);
3499     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3500     Valtype addend = This::extract_arm_movw_movt_addend(val);
3501     Valtype x = ((psymval->value(object, addend) | thumb_bit)
3502                  - relative_address_base);
3503     val = This::insert_val_arm_movw_movt(val, x);
3504     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3505     return ((check_overflow && Bits<16>::has_overflow32(x))
3506             ? This::STATUS_OVERFLOW
3507             : This::STATUS_OKAY);
3508   }
3509
3510   // R_ARM_MOVT_ABS: S + A      (relative address base is 0)
3511   // R_ARM_MOVT_PREL: S + A - P
3512   // R_ARM_MOVT_BREL: S + A - B(S)
3513   static inline typename This::Status
3514   movt(unsigned char* view,
3515        const Sized_relobj_file<32, big_endian>* object,
3516        const Symbol_value<32>* psymval,
3517        Arm_address relative_address_base)
3518   {
3519     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3520     Valtype* wv = reinterpret_cast<Valtype*>(view);
3521     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3522     Valtype addend = This::extract_arm_movw_movt_addend(val);
3523     Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3524     val = This::insert_val_arm_movw_movt(val, x);
3525     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3526     // FIXME: IHI0044D says that we should check for overflow.
3527     return This::STATUS_OKAY;
3528   }
3529
3530   // R_ARM_THM_MOVW_ABS_NC: S + A | T           (relative_address_base is 0)
3531   // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3532   // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3533   // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3534   static inline typename This::Status
3535   thm_movw(unsigned char* view,
3536            const Sized_relobj_file<32, big_endian>* object,
3537            const Symbol_value<32>* psymval,
3538            Arm_address relative_address_base,
3539            Arm_address thumb_bit,
3540            bool check_overflow)
3541   {
3542     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3543     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3544     Valtype* wv = reinterpret_cast<Valtype*>(view);
3545     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3546                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3547     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3548     Reltype x =
3549       (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3550     val = This::insert_val_thumb_movw_movt(val, x);
3551     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3552     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3553     return ((check_overflow && Bits<16>::has_overflow32(x))
3554             ? This::STATUS_OVERFLOW
3555             : This::STATUS_OKAY);
3556   }
3557
3558   // R_ARM_THM_MOVT_ABS: S + A          (relative address base is 0)
3559   // R_ARM_THM_MOVT_PREL: S + A - P
3560   // R_ARM_THM_MOVT_BREL: S + A - B(S)
3561   static inline typename This::Status
3562   thm_movt(unsigned char* view,
3563            const Sized_relobj_file<32, big_endian>* object,
3564            const Symbol_value<32>* psymval,
3565            Arm_address relative_address_base)
3566   {
3567     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3568     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3569     Valtype* wv = reinterpret_cast<Valtype*>(view);
3570     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3571                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3572     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3573     Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3574     val = This::insert_val_thumb_movw_movt(val, x);
3575     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3576     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3577     return This::STATUS_OKAY;
3578   }
3579
3580   // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3581   static inline typename This::Status
3582   thm_alu11(unsigned char* view,
3583             const Sized_relobj_file<32, big_endian>* object,
3584             const Symbol_value<32>* psymval,
3585             Arm_address address,
3586             Arm_address thumb_bit)
3587   {
3588     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3589     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3590     Valtype* wv = reinterpret_cast<Valtype*>(view);
3591     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3592                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3593
3594     //        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
3595     // -----------------------------------------------------------------------
3596     // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd     |imm8
3597     // ADDW   1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd     |imm8
3598     // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd     |imm8
3599     // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd     |imm8
3600     // SUBW   1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd     |imm8
3601     // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd     |imm8
3602
3603     // Determine a sign for the addend.
3604     const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3605                       || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3606     // Thumb2 addend encoding:
3607     // imm12 := i | imm3 | imm8
3608     int32_t addend = (insn & 0xff)
3609                      | ((insn & 0x00007000) >> 4)
3610                      | ((insn & 0x04000000) >> 15);
3611     // Apply a sign to the added.
3612     addend *= sign;
3613
3614     int32_t x = (psymval->value(object, addend) | thumb_bit)
3615                 - (address & 0xfffffffc);
3616     Reltype val = abs(x);
3617     // Mask out the value and a distinct part of the ADD/SUB opcode
3618     // (bits 7:5 of opword).
3619     insn = (insn & 0xfb0f8f00)
3620            | (val & 0xff)
3621            | ((val & 0x700) << 4)
3622            | ((val & 0x800) << 15);
3623     // Set the opcode according to whether the value to go in the
3624     // place is negative.
3625     if (x < 0)
3626       insn |= 0x00a00000;
3627
3628     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3629     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3630     return ((val > 0xfff) ?
3631             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3632   }
3633
3634   // R_ARM_THM_PC8: S + A - Pa (Thumb)
3635   static inline typename This::Status
3636   thm_pc8(unsigned char* view,
3637           const Sized_relobj_file<32, big_endian>* object,
3638           const Symbol_value<32>* psymval,
3639           Arm_address address)
3640   {
3641     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3642     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3643     Valtype* wv = reinterpret_cast<Valtype*>(view);
3644     Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3645     Reltype addend = ((insn & 0x00ff) << 2);
3646     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3647     Reltype val = abs(x);
3648     insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3649
3650     elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3651     return ((val > 0x03fc)
3652             ? This::STATUS_OVERFLOW
3653             : This::STATUS_OKAY);
3654   }
3655
3656   // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3657   static inline typename This::Status
3658   thm_pc12(unsigned char* view,
3659            const Sized_relobj_file<32, big_endian>* object,
3660            const Symbol_value<32>* psymval,
3661            Arm_address address)
3662   {
3663     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3664     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3665     Valtype* wv = reinterpret_cast<Valtype*>(view);
3666     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3667                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3668     // Determine a sign for the addend (positive if the U bit is 1).
3669     const int sign = (insn & 0x00800000) ? 1 : -1;
3670     int32_t addend = (insn & 0xfff);
3671     // Apply a sign to the added.
3672     addend *= sign;
3673
3674     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3675     Reltype val = abs(x);
3676     // Mask out and apply the value and the U bit.
3677     insn = (insn & 0xff7ff000) | (val & 0xfff);
3678     // Set the U bit according to whether the value to go in the
3679     // place is positive.
3680     if (x >= 0)
3681       insn |= 0x00800000;
3682
3683     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3684     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3685     return ((val > 0xfff) ?
3686             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3687   }
3688
3689   // R_ARM_V4BX
3690   static inline typename This::Status
3691   v4bx(const Relocate_info<32, big_endian>* relinfo,
3692        unsigned char* view,
3693        const Arm_relobj<big_endian>* object,
3694        const Arm_address address,
3695        const bool is_interworking)
3696   {
3697
3698     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3699     Valtype* wv = reinterpret_cast<Valtype*>(view);
3700     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3701
3702     // Ensure that we have a BX instruction.
3703     gold_assert((val & 0x0ffffff0) == 0x012fff10);
3704     const uint32_t reg = (val & 0xf);
3705     if (is_interworking && reg != 0xf)
3706       {
3707         Stub_table<big_endian>* stub_table =
3708             object->stub_table(relinfo->data_shndx);
3709         gold_assert(stub_table != NULL);
3710
3711         Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3712         gold_assert(stub != NULL);
3713
3714         int32_t veneer_address =
3715             stub_table->address() + stub->offset() - 8 - address;
3716         gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3717                     && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3718         // Replace with a branch to veneer (B <addr>)
3719         val = (val & 0xf0000000) | 0x0a000000
3720               | ((veneer_address >> 2) & 0x00ffffff);
3721       }
3722     else
3723       {
3724         // Preserve Rm (lowest four bits) and the condition code
3725         // (highest four bits). Other bits encode MOV PC,Rm.
3726         val = (val & 0xf000000f) | 0x01a0f000;
3727       }
3728     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3729     return This::STATUS_OKAY;
3730   }
3731
3732   // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3733   // R_ARM_ALU_PC_G0:    ((S + A) | T) - P
3734   // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3735   // R_ARM_ALU_PC_G1:    ((S + A) | T) - P
3736   // R_ARM_ALU_PC_G2:    ((S + A) | T) - P
3737   // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3738   // R_ARM_ALU_SB_G0:    ((S + A) | T) - B(S)
3739   // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3740   // R_ARM_ALU_SB_G1:    ((S + A) | T) - B(S)
3741   // R_ARM_ALU_SB_G2:    ((S + A) | T) - B(S)
3742   static inline typename This::Status
3743   arm_grp_alu(unsigned char* view,
3744         const Sized_relobj_file<32, big_endian>* object,
3745         const Symbol_value<32>* psymval,
3746         const int group,
3747         Arm_address address,
3748         Arm_address thumb_bit,
3749         bool check_overflow)
3750   {
3751     gold_assert(group >= 0 && group < 3);
3752     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3753     Valtype* wv = reinterpret_cast<Valtype*>(view);
3754     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3755
3756     // ALU group relocations are allowed only for the ADD/SUB instructions.
3757     // (0x00800000 - ADD, 0x00400000 - SUB)
3758     const Valtype opcode = insn & 0x01e00000;
3759     if (opcode != 0x00800000 && opcode != 0x00400000)
3760       return This::STATUS_BAD_RELOC;
3761
3762     // Determine a sign for the addend.
3763     const int sign = (opcode == 0x00800000) ? 1 : -1;
3764     // shifter = rotate_imm * 2
3765     const uint32_t shifter = (insn & 0xf00) >> 7;
3766     // Initial addend value.
3767     int32_t addend = insn & 0xff;
3768     // Rotate addend right by shifter.
3769     addend = (addend >> shifter) | (addend << (32 - shifter));
3770     // Apply a sign to the added.
3771     addend *= sign;
3772
3773     int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3774     Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3775     // Check for overflow if required
3776     if (check_overflow
3777         && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3778       return This::STATUS_OVERFLOW;
3779
3780     // Mask out the value and the ADD/SUB part of the opcode; take care
3781     // not to destroy the S bit.
3782     insn &= 0xff1ff000;
3783     // Set the opcode according to whether the value to go in the
3784     // place is negative.
3785     insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3786     // Encode the offset (encoded Gn).
3787     insn |= gn;
3788
3789     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3790     return This::STATUS_OKAY;
3791   }
3792
3793   // R_ARM_LDR_PC_G0: S + A - P
3794   // R_ARM_LDR_PC_G1: S + A - P
3795   // R_ARM_LDR_PC_G2: S + A - P
3796   // R_ARM_LDR_SB_G0: S + A - B(S)
3797   // R_ARM_LDR_SB_G1: S + A - B(S)
3798   // R_ARM_LDR_SB_G2: S + A - B(S)
3799   static inline typename This::Status
3800   arm_grp_ldr(unsigned char* view,
3801         const Sized_relobj_file<32, big_endian>* object,
3802         const Symbol_value<32>* psymval,
3803         const int group,
3804         Arm_address address)
3805   {
3806     gold_assert(group >= 0 && group < 3);
3807     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3808     Valtype* wv = reinterpret_cast<Valtype*>(view);
3809     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3810
3811     const int sign = (insn & 0x00800000) ? 1 : -1;
3812     int32_t addend = (insn & 0xfff) * sign;
3813     int32_t x = (psymval->value(object, addend) - address);
3814     // Calculate the relevant G(n-1) value to obtain this stage residual.
3815     Valtype residual =
3816         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3817     if (residual >= 0x1000)
3818       return This::STATUS_OVERFLOW;
3819
3820     // Mask out the value and U bit.
3821     insn &= 0xff7ff000;
3822     // Set the U bit for non-negative values.
3823     if (x >= 0)
3824       insn |= 0x00800000;
3825     insn |= residual;
3826
3827     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3828     return This::STATUS_OKAY;
3829   }
3830
3831   // R_ARM_LDRS_PC_G0: S + A - P
3832   // R_ARM_LDRS_PC_G1: S + A - P
3833   // R_ARM_LDRS_PC_G2: S + A - P
3834   // R_ARM_LDRS_SB_G0: S + A - B(S)
3835   // R_ARM_LDRS_SB_G1: S + A - B(S)
3836   // R_ARM_LDRS_SB_G2: S + A - B(S)
3837   static inline typename This::Status
3838   arm_grp_ldrs(unsigned char* view,
3839         const Sized_relobj_file<32, big_endian>* object,
3840         const Symbol_value<32>* psymval,
3841         const int group,
3842         Arm_address address)
3843   {
3844     gold_assert(group >= 0 && group < 3);
3845     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3846     Valtype* wv = reinterpret_cast<Valtype*>(view);
3847     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3848
3849     const int sign = (insn & 0x00800000) ? 1 : -1;
3850     int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3851     int32_t x = (psymval->value(object, addend) - address);
3852     // Calculate the relevant G(n-1) value to obtain this stage residual.
3853     Valtype residual =
3854         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3855    if (residual >= 0x100)
3856       return This::STATUS_OVERFLOW;
3857
3858     // Mask out the value and U bit.
3859     insn &= 0xff7ff0f0;
3860     // Set the U bit for non-negative values.
3861     if (x >= 0)
3862       insn |= 0x00800000;
3863     insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3864
3865     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3866     return This::STATUS_OKAY;
3867   }
3868
3869   // R_ARM_LDC_PC_G0: S + A - P
3870   // R_ARM_LDC_PC_G1: S + A - P
3871   // R_ARM_LDC_PC_G2: S + A - P
3872   // R_ARM_LDC_SB_G0: S + A - B(S)
3873   // R_ARM_LDC_SB_G1: S + A - B(S)
3874   // R_ARM_LDC_SB_G2: S + A - B(S)
3875   static inline typename This::Status
3876   arm_grp_ldc(unsigned char* view,
3877       const Sized_relobj_file<32, big_endian>* object,
3878       const Symbol_value<32>* psymval,
3879       const int group,
3880       Arm_address address)
3881   {
3882     gold_assert(group >= 0 && group < 3);
3883     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3884     Valtype* wv = reinterpret_cast<Valtype*>(view);
3885     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3886
3887     const int sign = (insn & 0x00800000) ? 1 : -1;
3888     int32_t addend = ((insn & 0xff) << 2) * sign;
3889     int32_t x = (psymval->value(object, addend) - address);
3890     // Calculate the relevant G(n-1) value to obtain this stage residual.
3891     Valtype residual =
3892       Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3893     if ((residual & 0x3) != 0 || residual >= 0x400)
3894       return This::STATUS_OVERFLOW;
3895
3896     // Mask out the value and U bit.
3897     insn &= 0xff7fff00;
3898     // Set the U bit for non-negative values.
3899     if (x >= 0)
3900       insn |= 0x00800000;
3901     insn |= (residual >> 2);
3902
3903     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3904     return This::STATUS_OKAY;
3905   }
3906 };
3907
3908 // Relocate ARM long branches.  This handles relocation types
3909 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3910 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3911 // undefined and we do not use PLT in this relocation.  In such a case,
3912 // the branch is converted into an NOP.
3913
3914 template<bool big_endian>
3915 typename Arm_relocate_functions<big_endian>::Status
3916 Arm_relocate_functions<big_endian>::arm_branch_common(
3917     unsigned int r_type,
3918     const Relocate_info<32, big_endian>* relinfo,
3919     unsigned char* view,
3920     const Sized_symbol<32>* gsym,
3921     const Arm_relobj<big_endian>* object,
3922     unsigned int r_sym,
3923     const Symbol_value<32>* psymval,
3924     Arm_address address,
3925     Arm_address thumb_bit,
3926     bool is_weakly_undefined_without_plt)
3927 {
3928   typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3929   Valtype* wv = reinterpret_cast<Valtype*>(view);
3930   Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3931
3932   bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3933                     && ((val & 0x0f000000UL) == 0x0a000000UL);
3934   bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3935   bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3936                           && ((val & 0x0f000000UL) == 0x0b000000UL);
3937   bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3938   bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3939
3940   // Check that the instruction is valid.
3941   if (r_type == elfcpp::R_ARM_CALL)
3942     {
3943       if (!insn_is_uncond_bl && !insn_is_blx)
3944         return This::STATUS_BAD_RELOC;
3945     }
3946   else if (r_type == elfcpp::R_ARM_JUMP24)
3947     {
3948       if (!insn_is_b && !insn_is_cond_bl)
3949         return This::STATUS_BAD_RELOC;
3950     }
3951   else if (r_type == elfcpp::R_ARM_PLT32)
3952     {
3953       if (!insn_is_any_branch)
3954         return This::STATUS_BAD_RELOC;
3955     }
3956   else if (r_type == elfcpp::R_ARM_XPC25)
3957     {
3958       // FIXME: AAELF document IH0044C does not say much about it other
3959       // than it being obsolete.
3960       if (!insn_is_any_branch)
3961         return This::STATUS_BAD_RELOC;
3962     }
3963   else
3964     gold_unreachable();
3965
3966   // A branch to an undefined weak symbol is turned into a jump to
3967   // the next instruction unless a PLT entry will be created.
3968   // Do the same for local undefined symbols.
3969   // The jump to the next instruction is optimized as a NOP depending
3970   // on the architecture.
3971   const Target_arm<big_endian>* arm_target =
3972     Target_arm<big_endian>::default_target();
3973   if (is_weakly_undefined_without_plt)
3974     {
3975       gold_assert(!parameters->options().relocatable());
3976       Valtype cond = val & 0xf0000000U;
3977       if (arm_target->may_use_arm_nop())
3978         val = cond | 0x0320f000;
3979       else
3980         val = cond | 0x01a00000;        // Using pre-UAL nop: mov r0, r0.
3981       elfcpp::Swap<32, big_endian>::writeval(wv, val);
3982       return This::STATUS_OKAY;
3983     }
3984
3985   Valtype addend = Bits<26>::sign_extend32(val << 2);
3986   Valtype branch_target = psymval->value(object, addend);
3987   int32_t branch_offset = branch_target - address;
3988
3989   // We need a stub if the branch offset is too large or if we need
3990   // to switch mode.
3991   bool may_use_blx = arm_target->may_use_v5t_interworking();
3992   Reloc_stub* stub = NULL;
3993
3994   if (!parameters->options().relocatable()
3995       && (Bits<26>::has_overflow32(branch_offset)
3996           || ((thumb_bit != 0)
3997               && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3998     {
3999       Valtype unadjusted_branch_target = psymval->value(object, 0);
4000
4001       Stub_type stub_type =
4002         Reloc_stub::stub_type_for_reloc(r_type, address,
4003                                         unadjusted_branch_target,
4004                                         (thumb_bit != 0));
4005       if (stub_type != arm_stub_none)
4006         {
4007           Stub_table<big_endian>* stub_table =
4008             object->stub_table(relinfo->data_shndx);
4009           gold_assert(stub_table != NULL);
4010
4011           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4012           stub = stub_table->find_reloc_stub(stub_key);
4013           gold_assert(stub != NULL);
4014           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4015           branch_target = stub_table->address() + stub->offset() + addend;
4016           branch_offset = branch_target - address;
4017           gold_assert(!Bits<26>::has_overflow32(branch_offset));
4018         }
4019     }
4020
4021   // At this point, if we still need to switch mode, the instruction
4022   // must either be a BLX or a BL that can be converted to a BLX.
4023   if (thumb_bit != 0)
4024     {
4025       // Turn BL to BLX.
4026       gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
4027       val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
4028     }
4029
4030   val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL);
4031   elfcpp::Swap<32, big_endian>::writeval(wv, val);
4032   return (Bits<26>::has_overflow32(branch_offset)
4033           ? This::STATUS_OVERFLOW
4034           : This::STATUS_OKAY);
4035 }
4036
4037 // Relocate THUMB long branches.  This handles relocation types
4038 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
4039 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
4040 // undefined and we do not use PLT in this relocation.  In such a case,
4041 // the branch is converted into an NOP.
4042
4043 template<bool big_endian>
4044 typename Arm_relocate_functions<big_endian>::Status
4045 Arm_relocate_functions<big_endian>::thumb_branch_common(
4046     unsigned int r_type,
4047     const Relocate_info<32, big_endian>* relinfo,
4048     unsigned char* view,
4049     const Sized_symbol<32>* gsym,
4050     const Arm_relobj<big_endian>* object,
4051     unsigned int r_sym,
4052     const Symbol_value<32>* psymval,
4053     Arm_address address,
4054     Arm_address thumb_bit,
4055     bool is_weakly_undefined_without_plt)
4056 {
4057   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4058   Valtype* wv = reinterpret_cast<Valtype*>(view);
4059   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4060   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4061
4062   // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
4063   // into account.
4064   bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
4065   bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
4066
4067   // Check that the instruction is valid.
4068   if (r_type == elfcpp::R_ARM_THM_CALL)
4069     {
4070       if (!is_bl_insn && !is_blx_insn)
4071         return This::STATUS_BAD_RELOC;
4072     }
4073   else if (r_type == elfcpp::R_ARM_THM_JUMP24)
4074     {
4075       // This cannot be a BLX.
4076       if (!is_bl_insn)
4077         return This::STATUS_BAD_RELOC;
4078     }
4079   else if (r_type == elfcpp::R_ARM_THM_XPC22)
4080     {
4081       // Check for Thumb to Thumb call.
4082       if (!is_blx_insn)
4083         return This::STATUS_BAD_RELOC;
4084       if (thumb_bit != 0)
4085         {
4086           gold_warning(_("%s: Thumb BLX instruction targets "
4087                          "thumb function '%s'."),
4088                          object->name().c_str(),
4089                          (gsym ? gsym->name() : "(local)"));
4090           // Convert BLX to BL.
4091           lower_insn |= 0x1000U;
4092         }
4093     }
4094   else
4095     gold_unreachable();
4096
4097   // A branch to an undefined weak symbol is turned into a jump to
4098   // the next instruction unless a PLT entry will be created.
4099   // The jump to the next instruction is optimized as a NOP.W for
4100   // Thumb-2 enabled architectures.
4101   const Target_arm<big_endian>* arm_target =
4102     Target_arm<big_endian>::default_target();
4103   if (is_weakly_undefined_without_plt)
4104     {
4105       gold_assert(!parameters->options().relocatable());
4106       if (arm_target->may_use_thumb2_nop())
4107         {
4108           elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4109           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4110         }
4111       else
4112         {
4113           elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4114           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4115         }
4116       return This::STATUS_OKAY;
4117     }
4118
4119   int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4120   Arm_address branch_target = psymval->value(object, addend);
4121
4122   // For BLX, bit 1 of target address comes from bit 1 of base address.
4123   bool may_use_blx = arm_target->may_use_v5t_interworking();
4124   if (thumb_bit == 0 && may_use_blx)
4125     branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4126
4127   int32_t branch_offset = branch_target - address;
4128
4129   // We need a stub if the branch offset is too large or if we need
4130   // to switch mode.
4131   bool thumb2 = arm_target->using_thumb2();
4132   if (!parameters->options().relocatable()
4133       && ((!thumb2 && Bits<23>::has_overflow32(branch_offset))
4134           || (thumb2 && Bits<25>::has_overflow32(branch_offset))
4135           || ((thumb_bit == 0)
4136               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4137                   || r_type == elfcpp::R_ARM_THM_JUMP24))))
4138     {
4139       Arm_address unadjusted_branch_target = psymval->value(object, 0);
4140
4141       Stub_type stub_type =
4142         Reloc_stub::stub_type_for_reloc(r_type, address,
4143                                         unadjusted_branch_target,
4144                                         (thumb_bit != 0));
4145
4146       if (stub_type != arm_stub_none)
4147         {
4148           Stub_table<big_endian>* stub_table =
4149             object->stub_table(relinfo->data_shndx);
4150           gold_assert(stub_table != NULL);
4151
4152           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4153           Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4154           gold_assert(stub != NULL);
4155           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4156           branch_target = stub_table->address() + stub->offset() + addend;
4157           if (thumb_bit == 0 && may_use_blx)
4158             branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4159           branch_offset = branch_target - address;
4160         }
4161     }
4162
4163   // At this point, if we still need to switch mode, the instruction
4164   // must either be a BLX or a BL that can be converted to a BLX.
4165   if (thumb_bit == 0)
4166     {
4167       gold_assert(may_use_blx
4168                   && (r_type == elfcpp::R_ARM_THM_CALL
4169                       || r_type == elfcpp::R_ARM_THM_XPC22));
4170       // Make sure this is a BLX.
4171       lower_insn &= ~0x1000U;
4172     }
4173   else
4174     {
4175       // Make sure this is a BL.
4176       lower_insn |= 0x1000U;
4177     }
4178
4179   // For a BLX instruction, make sure that the relocation is rounded up
4180   // to a word boundary.  This follows the semantics of the instruction
4181   // which specifies that bit 1 of the target address will come from bit
4182   // 1 of the base address.
4183   if ((lower_insn & 0x5000U) == 0x4000U)
4184     gold_assert((branch_offset & 3) == 0);
4185
4186   // Put BRANCH_OFFSET back into the insn.  Assumes two's complement.
4187   // We use the Thumb-2 encoding, which is safe even if dealing with
4188   // a Thumb-1 instruction by virtue of our overflow check above.  */
4189   upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4190   lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4191
4192   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4193   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4194
4195   gold_assert(!Bits<25>::has_overflow32(branch_offset));
4196
4197   return ((thumb2
4198            ? Bits<25>::has_overflow32(branch_offset)
4199            : Bits<23>::has_overflow32(branch_offset))
4200           ? This::STATUS_OVERFLOW
4201           : This::STATUS_OKAY);
4202 }
4203
4204 // Relocate THUMB-2 long conditional branches.
4205 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
4206 // undefined and we do not use PLT in this relocation.  In such a case,
4207 // the branch is converted into an NOP.
4208
4209 template<bool big_endian>
4210 typename Arm_relocate_functions<big_endian>::Status
4211 Arm_relocate_functions<big_endian>::thm_jump19(
4212     unsigned char* view,
4213     const Arm_relobj<big_endian>* object,
4214     const Symbol_value<32>* psymval,
4215     Arm_address address,
4216     Arm_address thumb_bit)
4217 {
4218   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4219   Valtype* wv = reinterpret_cast<Valtype*>(view);
4220   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4221   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4222   int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4223
4224   Arm_address branch_target = psymval->value(object, addend);
4225   int32_t branch_offset = branch_target - address;
4226
4227   // ??? Should handle interworking?  GCC might someday try to
4228   // use this for tail calls.
4229   // FIXME: We do support thumb entry to PLT yet.
4230   if (thumb_bit == 0)
4231     {
4232       gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4233       return This::STATUS_BAD_RELOC;
4234     }
4235
4236   // Put RELOCATION back into the insn.
4237   upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4238   lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4239
4240   // Put the relocated value back in the object file:
4241   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4242   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4243
4244   return (Bits<21>::has_overflow32(branch_offset)
4245           ? This::STATUS_OVERFLOW
4246           : This::STATUS_OKAY);
4247 }
4248
4249 // Get the GOT section, creating it if necessary.
4250
4251 template<bool big_endian>
4252 Arm_output_data_got<big_endian>*
4253 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4254 {
4255   if (this->got_ == NULL)
4256     {
4257       gold_assert(symtab != NULL && layout != NULL);
4258
4259       // When using -z now, we can treat .got as a relro section.
4260       // Without -z now, it is modified after program startup by lazy
4261       // PLT relocations.
4262       bool is_got_relro = parameters->options().now();
4263       Output_section_order got_order = (is_got_relro
4264                                         ? ORDER_RELRO_LAST
4265                                         : ORDER_DATA);
4266
4267       // Unlike some targets (.e.g x86), ARM does not use separate .got and
4268       // .got.plt sections in output.  The output .got section contains both
4269       // PLT and non-PLT GOT entries.
4270       this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4271
4272       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4273                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4274                                       this->got_, got_order, is_got_relro);
4275
4276       // The old GNU linker creates a .got.plt section.  We just
4277       // create another set of data in the .got section.  Note that we
4278       // always create a PLT if we create a GOT, although the PLT
4279       // might be empty.
4280       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4281       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4282                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4283                                       this->got_plt_, got_order, is_got_relro);
4284
4285       // The first three entries are reserved.
4286       this->got_plt_->set_current_data_size(3 * 4);
4287
4288       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4289       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4290                                     Symbol_table::PREDEFINED,
4291                                     this->got_plt_,
4292                                     0, 0, elfcpp::STT_OBJECT,
4293                                     elfcpp::STB_LOCAL,
4294                                     elfcpp::STV_HIDDEN, 0,
4295                                     false, false);
4296
4297       // If there are any IRELATIVE relocations, they get GOT entries
4298       // in .got.plt after the jump slot entries.
4299       this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT");
4300       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4301                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4302                                       this->got_irelative_,
4303                                       got_order, is_got_relro);
4304
4305     }
4306   return this->got_;
4307 }
4308
4309 // Get the dynamic reloc section, creating it if necessary.
4310
4311 template<bool big_endian>
4312 typename Target_arm<big_endian>::Reloc_section*
4313 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4314 {
4315   if (this->rel_dyn_ == NULL)
4316     {
4317       gold_assert(layout != NULL);
4318       // Create both relocation sections in the same place, so as to ensure
4319       // their relative order in the output section.
4320       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4321       this->rel_irelative_ = new Reloc_section(false);
4322       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4323                                       elfcpp::SHF_ALLOC, this->rel_dyn_,
4324                                       ORDER_DYNAMIC_RELOCS, false);
4325       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4326                                       elfcpp::SHF_ALLOC, this->rel_irelative_,
4327                                       ORDER_DYNAMIC_RELOCS, false);
4328     }
4329   return this->rel_dyn_;
4330 }
4331
4332
4333 // Get the section to use for IRELATIVE relocs, creating it if necessary.  These
4334 // go in .rela.dyn, but only after all other dynamic relocations.  They need to
4335 // follow the other dynamic relocations so that they can refer to global
4336 // variables initialized by those relocs.
4337
4338 template<bool big_endian>
4339 typename Target_arm<big_endian>::Reloc_section*
4340 Target_arm<big_endian>::rel_irelative_section(Layout* layout)
4341 {
4342   if (this->rel_irelative_ == NULL)
4343     {
4344       // Delegate the creation to rel_dyn_section so as to ensure their order in
4345       // the output section.
4346       this->rel_dyn_section(layout);
4347       gold_assert(this->rel_irelative_ != NULL
4348                   && (this->rel_dyn_->output_section()
4349                       == this->rel_irelative_->output_section()));
4350     }
4351   return this->rel_irelative_;
4352 }
4353
4354
4355 // Insn_template methods.
4356
4357 // Return byte size of an instruction template.
4358
4359 size_t
4360 Insn_template::size() const
4361 {
4362   switch (this->type())
4363     {
4364     case THUMB16_TYPE:
4365     case THUMB16_SPECIAL_TYPE:
4366       return 2;
4367     case ARM_TYPE:
4368     case THUMB32_TYPE:
4369     case DATA_TYPE:
4370       return 4;
4371     default:
4372       gold_unreachable();
4373     }
4374 }
4375
4376 // Return alignment of an instruction template.
4377
4378 unsigned
4379 Insn_template::alignment() const
4380 {
4381   switch (this->type())
4382     {
4383     case THUMB16_TYPE:
4384     case THUMB16_SPECIAL_TYPE:
4385     case THUMB32_TYPE:
4386       return 2;
4387     case ARM_TYPE:
4388     case DATA_TYPE:
4389       return 4;
4390     default:
4391       gold_unreachable();
4392     }
4393 }
4394
4395 // Stub_template methods.
4396
4397 Stub_template::Stub_template(
4398     Stub_type type, const Insn_template* insns,
4399      size_t insn_count)
4400   : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4401     entry_in_thumb_mode_(false), relocs_()
4402 {
4403   off_t offset = 0;
4404
4405   // Compute byte size and alignment of stub template.
4406   for (size_t i = 0; i < insn_count; i++)
4407     {
4408       unsigned insn_alignment = insns[i].alignment();
4409       size_t insn_size = insns[i].size();
4410       gold_assert((offset & (insn_alignment - 1)) == 0);
4411       this->alignment_ = std::max(this->alignment_, insn_alignment);
4412       switch (insns[i].type())
4413         {
4414         case Insn_template::THUMB16_TYPE:
4415         case Insn_template::THUMB16_SPECIAL_TYPE:
4416           if (i == 0)
4417             this->entry_in_thumb_mode_ = true;
4418           break;
4419
4420         case Insn_template::THUMB32_TYPE:
4421           if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4422             this->relocs_.push_back(Reloc(i, offset));
4423           if (i == 0)
4424             this->entry_in_thumb_mode_ = true;
4425           break;
4426
4427         case Insn_template::ARM_TYPE:
4428           // Handle cases where the target is encoded within the
4429           // instruction.
4430           if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4431             this->relocs_.push_back(Reloc(i, offset));
4432           break;
4433
4434         case Insn_template::DATA_TYPE:
4435           // Entry point cannot be data.
4436           gold_assert(i != 0);
4437           this->relocs_.push_back(Reloc(i, offset));
4438           break;
4439
4440         default:
4441           gold_unreachable();
4442         }
4443       offset += insn_size;
4444     }
4445   this->size_ = offset;
4446 }
4447
4448 // Stub methods.
4449
4450 // Template to implement do_write for a specific target endianness.
4451
4452 template<bool big_endian>
4453 void inline
4454 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4455 {
4456   const Stub_template* stub_template = this->stub_template();
4457   const Insn_template* insns = stub_template->insns();
4458
4459   // FIXME:  We do not handle BE8 encoding yet.
4460   unsigned char* pov = view;
4461   for (size_t i = 0; i < stub_template->insn_count(); i++)
4462     {
4463       switch (insns[i].type())
4464         {
4465         case Insn_template::THUMB16_TYPE:
4466           elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4467           break;
4468         case Insn_template::THUMB16_SPECIAL_TYPE:
4469           elfcpp::Swap<16, big_endian>::writeval(
4470               pov,
4471               this->thumb16_special(i));
4472           break;
4473         case Insn_template::THUMB32_TYPE:
4474           {
4475             uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4476             uint32_t lo = insns[i].data() & 0xffff;
4477             elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4478             elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4479           }
4480           break;
4481         case Insn_template::ARM_TYPE:
4482         case Insn_template::DATA_TYPE:
4483           elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4484           break;
4485         default:
4486           gold_unreachable();
4487         }
4488       pov += insns[i].size();
4489     }
4490   gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4491 }
4492
4493 // Reloc_stub::Key methods.
4494
4495 // Dump a Key as a string for debugging.
4496
4497 std::string
4498 Reloc_stub::Key::name() const
4499 {
4500   if (this->r_sym_ == invalid_index)
4501     {
4502       // Global symbol key name
4503       // <stub-type>:<symbol name>:<addend>.
4504       const std::string sym_name = this->u_.symbol->name();
4505       // We need to print two hex number and two colons.  So just add 100 bytes
4506       // to the symbol name size.
4507       size_t len = sym_name.size() + 100;
4508       char* buffer = new char[len];
4509       int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4510                        sym_name.c_str(), this->addend_);
4511       gold_assert(c > 0 && c < static_cast<int>(len));
4512       delete[] buffer;
4513       return std::string(buffer);
4514     }
4515   else
4516     {
4517       // local symbol key name
4518       // <stub-type>:<object>:<r_sym>:<addend>.
4519       const size_t len = 200;
4520       char buffer[len];
4521       int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4522                        this->u_.relobj, this->r_sym_, this->addend_);
4523       gold_assert(c > 0 && c < static_cast<int>(len));
4524       return std::string(buffer);
4525     }
4526 }
4527
4528 // Reloc_stub methods.
4529
4530 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4531 // LOCATION to DESTINATION.
4532 // This code is based on the arm_type_of_stub function in
4533 // bfd/elf32-arm.c.  We have changed the interface a little to keep the Stub
4534 // class simple.
4535
4536 Stub_type
4537 Reloc_stub::stub_type_for_reloc(
4538    unsigned int r_type,
4539    Arm_address location,
4540    Arm_address destination,
4541    bool target_is_thumb)
4542 {
4543   Stub_type stub_type = arm_stub_none;
4544
4545   // This is a bit ugly but we want to avoid using a templated class for
4546   // big and little endianities.
4547   bool may_use_blx;
4548   bool should_force_pic_veneer = parameters->options().pic_veneer();
4549   bool thumb2;
4550   bool thumb_only;
4551   if (parameters->target().is_big_endian())
4552     {
4553       const Target_arm<true>* big_endian_target =
4554         Target_arm<true>::default_target();
4555       may_use_blx = big_endian_target->may_use_v5t_interworking();
4556       should_force_pic_veneer |= big_endian_target->should_force_pic_veneer();
4557       thumb2 = big_endian_target->using_thumb2();
4558       thumb_only = big_endian_target->using_thumb_only();
4559     }
4560   else
4561     {
4562       const Target_arm<false>* little_endian_target =
4563         Target_arm<false>::default_target();
4564       may_use_blx = little_endian_target->may_use_v5t_interworking();
4565       should_force_pic_veneer |=
4566         little_endian_target->should_force_pic_veneer();
4567       thumb2 = little_endian_target->using_thumb2();
4568       thumb_only = little_endian_target->using_thumb_only();
4569     }
4570
4571   int64_t branch_offset;
4572   bool output_is_position_independent =
4573       parameters->options().output_is_position_independent();
4574   if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4575     {
4576       // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4577       // base address (instruction address + 4).
4578       if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4579         destination = Bits<32>::bit_select32(destination, location, 0x2);
4580       branch_offset = static_cast<int64_t>(destination) - location;
4581
4582       // Handle cases where:
4583       // - this call goes too far (different Thumb/Thumb2 max
4584       //   distance)
4585       // - it's a Thumb->Arm call and blx is not available, or it's a
4586       //   Thumb->Arm branch (not bl). A stub is needed in this case.
4587       if ((!thumb2
4588             && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4589                 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4590           || (thumb2
4591               && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4592                   || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4593           || ((!target_is_thumb)
4594               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4595                   || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4596         {
4597           if (target_is_thumb)
4598             {
4599               // Thumb to thumb.
4600               if (!thumb_only)
4601                 {
4602                   stub_type = (output_is_position_independent
4603                                || should_force_pic_veneer)
4604                     // PIC stubs.
4605                     ? ((may_use_blx
4606                         && (r_type == elfcpp::R_ARM_THM_CALL))
4607                        // V5T and above. Stub starts with ARM code, so
4608                        // we must be able to switch mode before
4609                        // reaching it, which is only possible for 'bl'
4610                        // (ie R_ARM_THM_CALL relocation).
4611                        ? arm_stub_long_branch_any_thumb_pic
4612                        // On V4T, use Thumb code only.
4613                        : arm_stub_long_branch_v4t_thumb_thumb_pic)
4614
4615                     // non-PIC stubs.
4616                     : ((may_use_blx
4617                         && (r_type == elfcpp::R_ARM_THM_CALL))
4618                        ? arm_stub_long_branch_any_any // V5T and above.
4619                        : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4620                 }
4621               else
4622                 {
4623                   stub_type = (output_is_position_independent
4624                                || should_force_pic_veneer)
4625                     ? arm_stub_long_branch_thumb_only_pic       // PIC stub.
4626                     : arm_stub_long_branch_thumb_only;  // non-PIC stub.
4627                 }
4628             }
4629           else
4630             {
4631               // Thumb to arm.
4632
4633               // FIXME: We should check that the input section is from an
4634               // object that has interwork enabled.
4635
4636               stub_type = (output_is_position_independent
4637                            || should_force_pic_veneer)
4638                 // PIC stubs.
4639                 ? ((may_use_blx
4640                     && (r_type == elfcpp::R_ARM_THM_CALL))
4641                    ? arm_stub_long_branch_any_arm_pic   // V5T and above.
4642                    : arm_stub_long_branch_v4t_thumb_arm_pic)    // V4T.
4643
4644                 // non-PIC stubs.
4645                 : ((may_use_blx
4646                     && (r_type == elfcpp::R_ARM_THM_CALL))
4647                    ? arm_stub_long_branch_any_any       // V5T and above.
4648                    : arm_stub_long_branch_v4t_thumb_arm);       // V4T.
4649
4650               // Handle v4t short branches.
4651               if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4652                   && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4653                   && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4654                 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4655             }
4656         }
4657     }
4658   else if (r_type == elfcpp::R_ARM_CALL
4659            || r_type == elfcpp::R_ARM_JUMP24
4660            || r_type == elfcpp::R_ARM_PLT32)
4661     {
4662       branch_offset = static_cast<int64_t>(destination) - location;
4663       if (target_is_thumb)
4664         {
4665           // Arm to thumb.
4666
4667           // FIXME: We should check that the input section is from an
4668           // object that has interwork enabled.
4669
4670           // We have an extra 2-bytes reach because of
4671           // the mode change (bit 24 (H) of BLX encoding).
4672           if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4673               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4674               || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4675               || (r_type == elfcpp::R_ARM_JUMP24)
4676               || (r_type == elfcpp::R_ARM_PLT32))
4677             {
4678               stub_type = (output_is_position_independent
4679                            || should_force_pic_veneer)
4680                 // PIC stubs.
4681                 ? (may_use_blx
4682                    ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4683                    : arm_stub_long_branch_v4t_arm_thumb_pic)    // V4T stub.
4684
4685                 // non-PIC stubs.
4686                 : (may_use_blx
4687                    ? arm_stub_long_branch_any_any       // V5T and above.
4688                    : arm_stub_long_branch_v4t_arm_thumb);       // V4T.
4689             }
4690         }
4691       else
4692         {
4693           // Arm to arm.
4694           if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4695               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4696             {
4697               stub_type = (output_is_position_independent
4698                            || should_force_pic_veneer)
4699                 ? arm_stub_long_branch_any_arm_pic      // PIC stubs.
4700                 : arm_stub_long_branch_any_any;         /// non-PIC.
4701             }
4702         }
4703     }
4704
4705   return stub_type;
4706 }
4707
4708 // Cortex_a8_stub methods.
4709
4710 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4711 // I is the position of the instruction template in the stub template.
4712
4713 uint16_t
4714 Cortex_a8_stub::do_thumb16_special(size_t i)
4715 {
4716   // The only use of this is to copy condition code from a conditional
4717   // branch being worked around to the corresponding conditional branch in
4718   // to the stub.
4719   gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4720               && i == 0);
4721   uint16_t data = this->stub_template()->insns()[i].data();
4722   gold_assert((data & 0xff00U) == 0xd000U);
4723   data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4724   return data;
4725 }
4726
4727 // Stub_factory methods.
4728
4729 Stub_factory::Stub_factory()
4730 {
4731   // The instruction template sequences are declared as static
4732   // objects and initialized first time the constructor runs.
4733
4734   // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4735   // to reach the stub if necessary.
4736   static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4737     {
4738       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4739       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4740                                                 // dcd   R_ARM_ABS32(X)
4741     };
4742
4743   // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4744   // available.
4745   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4746     {
4747       Insn_template::arm_insn(0xe59fc000),      // ldr   ip, [pc, #0]
4748       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4749       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4750                                                 // dcd   R_ARM_ABS32(X)
4751     };
4752
4753   // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4754   static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4755     {
4756       Insn_template::thumb16_insn(0xb401),      // push {r0}
4757       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4758       Insn_template::thumb16_insn(0x4684),      // mov  ip, r0
4759       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4760       Insn_template::thumb16_insn(0x4760),      // bx   ip
4761       Insn_template::thumb16_insn(0xbf00),      // nop
4762       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4763                                                 // dcd  R_ARM_ABS32(X)
4764     };
4765
4766   // V4T Thumb -> Thumb long branch stub. Using the stack is not
4767   // allowed.
4768   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4769     {
4770       Insn_template::thumb16_insn(0x4778),      // bx   pc
4771       Insn_template::thumb16_insn(0x46c0),      // nop
4772       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4773       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4774       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4775                                                 // dcd  R_ARM_ABS32(X)
4776     };
4777
4778   // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4779   // available.
4780   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4781     {
4782       Insn_template::thumb16_insn(0x4778),      // bx   pc
4783       Insn_template::thumb16_insn(0x46c0),      // nop
4784       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4785       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4786                                                 // dcd   R_ARM_ABS32(X)
4787     };
4788
4789   // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4790   // one, when the destination is close enough.
4791   static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4792     {
4793       Insn_template::thumb16_insn(0x4778),              // bx   pc
4794       Insn_template::thumb16_insn(0x46c0),              // nop
4795       Insn_template::arm_rel_insn(0xea000000, -8),      // b    (X-8)
4796     };
4797
4798   // ARM/Thumb -> ARM long branch stub, PIC.  On V5T and above, use
4799   // blx to reach the stub if necessary.
4800   static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4801     {
4802       Insn_template::arm_insn(0xe59fc000),      // ldr   r12, [pc]
4803       Insn_template::arm_insn(0xe08ff00c),      // add   pc, pc, ip
4804       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4805                                                 // dcd   R_ARM_REL32(X-4)
4806     };
4807
4808   // ARM/Thumb -> Thumb long branch stub, PIC.  On V5T and above, use
4809   // blx to reach the stub if necessary.  We can not add into pc;
4810   // it is not guaranteed to mode switch (different in ARMv6 and
4811   // ARMv7).
4812   static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4813     {
4814       Insn_template::arm_insn(0xe59fc004),      // ldr   r12, [pc, #4]
4815       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4816       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4817       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4818                                                 // dcd   R_ARM_REL32(X)
4819     };
4820
4821   // V4T ARM -> ARM long branch stub, PIC.
4822   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4823     {
4824       Insn_template::arm_insn(0xe59fc004),      // ldr   ip, [pc, #4]
4825       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4826       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4827       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4828                                                 // dcd   R_ARM_REL32(X)
4829     };
4830
4831   // V4T Thumb -> ARM long branch stub, PIC.
4832   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4833     {
4834       Insn_template::thumb16_insn(0x4778),      // bx   pc
4835       Insn_template::thumb16_insn(0x46c0),      // nop
4836       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4837       Insn_template::arm_insn(0xe08cf00f),      // add  pc, ip, pc
4838       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4839                                                 // dcd  R_ARM_REL32(X)
4840     };
4841
4842   // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4843   // architectures.
4844   static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4845     {
4846       Insn_template::thumb16_insn(0xb401),      // push {r0}
4847       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4848       Insn_template::thumb16_insn(0x46fc),      // mov  ip, pc
4849       Insn_template::thumb16_insn(0x4484),      // add  ip, r0
4850       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4851       Insn_template::thumb16_insn(0x4760),      // bx   ip
4852       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4853                                                 // dcd  R_ARM_REL32(X)
4854     };
4855
4856   // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4857   // allowed.
4858   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4859     {
4860       Insn_template::thumb16_insn(0x4778),      // bx   pc
4861       Insn_template::thumb16_insn(0x46c0),      // nop
4862       Insn_template::arm_insn(0xe59fc004),      // ldr  ip, [pc, #4]
4863       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4864       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4865       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4866                                                 // dcd  R_ARM_REL32(X)
4867     };
4868
4869   // Cortex-A8 erratum-workaround stubs.
4870
4871   // Stub used for conditional branches (which may be beyond +/-1MB away,
4872   // so we can't use a conditional branch to reach this stub).
4873
4874   // original code:
4875   //
4876   //    b<cond> X
4877   // after:
4878   //
4879   static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4880     {
4881       Insn_template::thumb16_bcond_insn(0xd001),        //      b<cond>.n true
4882       Insn_template::thumb32_b_insn(0xf000b800, -4),    //      b.w after
4883       Insn_template::thumb32_b_insn(0xf000b800, -4)     // true:
4884                                                         //      b.w X
4885     };
4886
4887   // Stub used for b.w and bl.w instructions.
4888
4889   static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4890     {
4891       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4892     };
4893
4894   static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4895     {
4896       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4897     };
4898
4899   // Stub used for Thumb-2 blx.w instructions.  We modified the original blx.w
4900   // instruction (which switches to ARM mode) to point to this stub.  Jump to
4901   // the real destination using an ARM-mode branch.
4902   static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4903     {
4904       Insn_template::arm_rel_insn(0xea000000, -8)       // b dest
4905     };
4906
4907   // Stub used to provide an interworking for R_ARM_V4BX relocation
4908   // (bx r[n] instruction).
4909   static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4910     {
4911       Insn_template::arm_insn(0xe3100001),              // tst   r<n>, #1
4912       Insn_template::arm_insn(0x01a0f000),              // moveq pc, r<n>
4913       Insn_template::arm_insn(0xe12fff10)               // bx    r<n>
4914     };
4915
4916   // Fill in the stub template look-up table.  Stub templates are constructed
4917   // per instance of Stub_factory for fast look-up without locking
4918   // in a thread-enabled environment.
4919
4920   this->stub_templates_[arm_stub_none] =
4921     new Stub_template(arm_stub_none, NULL, 0);
4922
4923 #define DEF_STUB(x)     \
4924   do \
4925     { \
4926       size_t array_size \
4927         = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4928       Stub_type type = arm_stub_##x; \
4929       this->stub_templates_[type] = \
4930         new Stub_template(type, elf32_arm_stub_##x, array_size); \
4931     } \
4932   while (0);
4933
4934   DEF_STUBS
4935 #undef DEF_STUB
4936 }
4937
4938 // Stub_table methods.
4939
4940 // Remove all Cortex-A8 stub.
4941
4942 template<bool big_endian>
4943 void
4944 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4945 {
4946   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4947        p != this->cortex_a8_stubs_.end();
4948        ++p)
4949     delete p->second;
4950   this->cortex_a8_stubs_.clear();
4951 }
4952
4953 // Relocate one stub.  This is a helper for Stub_table::relocate_stubs().
4954
4955 template<bool big_endian>
4956 void
4957 Stub_table<big_endian>::relocate_stub(
4958     Stub* stub,
4959     const Relocate_info<32, big_endian>* relinfo,
4960     Target_arm<big_endian>* arm_target,
4961     Output_section* output_section,
4962     unsigned char* view,
4963     Arm_address address,
4964     section_size_type view_size)
4965 {
4966   const Stub_template* stub_template = stub->stub_template();
4967   if (stub_template->reloc_count() != 0)
4968     {
4969       // Adjust view to cover the stub only.
4970       section_size_type offset = stub->offset();
4971       section_size_type stub_size = stub_template->size();
4972       gold_assert(offset + stub_size <= view_size);
4973
4974       arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4975                                 address + offset, stub_size);
4976     }
4977 }
4978
4979 // Relocate all stubs in this stub table.
4980
4981 template<bool big_endian>
4982 void
4983 Stub_table<big_endian>::relocate_stubs(
4984     const Relocate_info<32, big_endian>* relinfo,
4985     Target_arm<big_endian>* arm_target,
4986     Output_section* output_section,
4987     unsigned char* view,
4988     Arm_address address,
4989     section_size_type view_size)
4990 {
4991   // If we are passed a view bigger than the stub table's.  we need to
4992   // adjust the view.
4993   gold_assert(address == this->address()
4994               && (view_size
4995                   == static_cast<section_size_type>(this->data_size())));
4996
4997   // Relocate all relocation stubs.
4998   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4999       p != this->reloc_stubs_.end();
5000       ++p)
5001     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
5002                         address, view_size);
5003
5004   // Relocate all Cortex-A8 stubs.
5005   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
5006        p != this->cortex_a8_stubs_.end();
5007        ++p)
5008     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
5009                         address, view_size);
5010
5011   // Relocate all ARM V4BX stubs.
5012   for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
5013        p != this->arm_v4bx_stubs_.end();
5014        ++p)
5015     {
5016       if (*p != NULL)
5017         this->relocate_stub(*p, relinfo, arm_target, output_section, view,
5018                             address, view_size);
5019     }
5020 }
5021
5022 // Write out the stubs to file.
5023
5024 template<bool big_endian>
5025 void
5026 Stub_table<big_endian>::do_write(Output_file* of)
5027 {
5028   off_t offset = this->offset();
5029   const section_size_type oview_size =
5030     convert_to_section_size_type(this->data_size());
5031   unsigned char* const oview = of->get_output_view(offset, oview_size);
5032
5033   // Write relocation stubs.
5034   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
5035       p != this->reloc_stubs_.end();
5036       ++p)
5037     {
5038       Reloc_stub* stub = p->second;
5039       Arm_address address = this->address() + stub->offset();
5040       gold_assert(address
5041                   == align_address(address,
5042                                    stub->stub_template()->alignment()));
5043       stub->write(oview + stub->offset(), stub->stub_template()->size(),
5044                   big_endian);
5045     }
5046
5047   // Write Cortex-A8 stubs.
5048   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5049        p != this->cortex_a8_stubs_.end();
5050        ++p)
5051     {
5052       Cortex_a8_stub* stub = p->second;
5053       Arm_address address = this->address() + stub->offset();
5054       gold_assert(address
5055                   == align_address(address,
5056                                    stub->stub_template()->alignment()));
5057       stub->write(oview + stub->offset(), stub->stub_template()->size(),
5058                   big_endian);
5059     }
5060
5061   // Write ARM V4BX relocation stubs.
5062   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5063        p != this->arm_v4bx_stubs_.end();
5064        ++p)
5065     {
5066       if (*p == NULL)
5067         continue;
5068
5069       Arm_address address = this->address() + (*p)->offset();
5070       gold_assert(address
5071                   == align_address(address,
5072                                    (*p)->stub_template()->alignment()));
5073       (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
5074                   big_endian);
5075     }
5076
5077   of->write_output_view(this->offset(), oview_size, oview);
5078 }
5079
5080 // Update the data size and address alignment of the stub table at the end
5081 // of a relaxation pass.   Return true if either the data size or the
5082 // alignment changed in this relaxation pass.
5083
5084 template<bool big_endian>
5085 bool
5086 Stub_table<big_endian>::update_data_size_and_addralign()
5087 {
5088   // Go over all stubs in table to compute data size and address alignment.
5089   off_t size = this->reloc_stubs_size_;
5090   unsigned addralign = this->reloc_stubs_addralign_;
5091
5092   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5093        p != this->cortex_a8_stubs_.end();
5094        ++p)
5095     {
5096       const Stub_template* stub_template = p->second->stub_template();
5097       addralign = std::max(addralign, stub_template->alignment());
5098       size = (align_address(size, stub_template->alignment())
5099               + stub_template->size());
5100     }
5101
5102   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5103        p != this->arm_v4bx_stubs_.end();
5104        ++p)
5105     {
5106       if (*p == NULL)
5107         continue;
5108
5109       const Stub_template* stub_template = (*p)->stub_template();
5110       addralign = std::max(addralign, stub_template->alignment());
5111       size = (align_address(size, stub_template->alignment())
5112               + stub_template->size());
5113     }
5114
5115   // Check if either data size or alignment changed in this pass.
5116   // Update prev_data_size_ and prev_addralign_.  These will be used
5117   // as the current data size and address alignment for the next pass.
5118   bool changed = size != this->prev_data_size_;
5119   this->prev_data_size_ = size;
5120
5121   if (addralign != this->prev_addralign_)
5122     changed = true;
5123   this->prev_addralign_ = addralign;
5124
5125   return changed;
5126 }
5127
5128 // Finalize the stubs.  This sets the offsets of the stubs within the stub
5129 // table.  It also marks all input sections needing Cortex-A8 workaround.
5130
5131 template<bool big_endian>
5132 void
5133 Stub_table<big_endian>::finalize_stubs()
5134 {
5135   off_t off = this->reloc_stubs_size_;
5136   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5137        p != this->cortex_a8_stubs_.end();
5138        ++p)
5139     {
5140       Cortex_a8_stub* stub = p->second;
5141       const Stub_template* stub_template = stub->stub_template();
5142       uint64_t stub_addralign = stub_template->alignment();
5143       off = align_address(off, stub_addralign);
5144       stub->set_offset(off);
5145       off += stub_template->size();
5146
5147       // Mark input section so that we can determine later if a code section
5148       // needs the Cortex-A8 workaround quickly.
5149       Arm_relobj<big_endian>* arm_relobj =
5150         Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5151       arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5152     }
5153
5154   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5155       p != this->arm_v4bx_stubs_.end();
5156       ++p)
5157     {
5158       if (*p == NULL)
5159         continue;
5160
5161       const Stub_template* stub_template = (*p)->stub_template();
5162       uint64_t stub_addralign = stub_template->alignment();
5163       off = align_address(off, stub_addralign);
5164       (*p)->set_offset(off);
5165       off += stub_template->size();
5166     }
5167
5168   gold_assert(off <= this->prev_data_size_);
5169 }
5170
5171 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5172 // and VIEW_ADDRESS + VIEW_SIZE - 1.  VIEW points to the mapped address
5173 // of the address range seen by the linker.
5174
5175 template<bool big_endian>
5176 void
5177 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5178     Target_arm<big_endian>* arm_target,
5179     unsigned char* view,
5180     Arm_address view_address,
5181     section_size_type view_size)
5182 {
5183   // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5184   for (Cortex_a8_stub_list::const_iterator p =
5185          this->cortex_a8_stubs_.lower_bound(view_address);
5186        ((p != this->cortex_a8_stubs_.end())
5187         && (p->first < (view_address + view_size)));
5188        ++p)
5189     {
5190       // We do not store the THUMB bit in the LSB of either the branch address
5191       // or the stub offset.  There is no need to strip the LSB.
5192       Arm_address branch_address = p->first;
5193       const Cortex_a8_stub* stub = p->second;
5194       Arm_address stub_address = this->address() + stub->offset();
5195
5196       // Offset of the branch instruction relative to this view.
5197       section_size_type offset =
5198         convert_to_section_size_type(branch_address - view_address);
5199       gold_assert((offset + 4) <= view_size);
5200
5201       arm_target->apply_cortex_a8_workaround(stub, stub_address,
5202                                              view + offset, branch_address);
5203     }
5204 }
5205
5206 // Arm_input_section methods.
5207
5208 // Initialize an Arm_input_section.
5209
5210 template<bool big_endian>
5211 void
5212 Arm_input_section<big_endian>::init()
5213 {
5214   Relobj* relobj = this->relobj();
5215   unsigned int shndx = this->shndx();
5216
5217   // We have to cache original size, alignment and contents to avoid locking
5218   // the original file.
5219   this->original_addralign_ =
5220     convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5221
5222   // This is not efficient but we expect only a small number of relaxed
5223   // input sections for stubs.
5224   section_size_type section_size;
5225   const unsigned char* section_contents =
5226     relobj->section_contents(shndx, &section_size, false);
5227   this->original_size_ =
5228     convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5229
5230   gold_assert(this->original_contents_ == NULL);
5231   this->original_contents_ = new unsigned char[section_size];
5232   memcpy(this->original_contents_, section_contents, section_size);
5233
5234   // We want to make this look like the original input section after
5235   // output sections are finalized.
5236   Output_section* os = relobj->output_section(shndx);
5237   off_t offset = relobj->output_section_offset(shndx);
5238   gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5239   this->set_address(os->address() + offset);
5240   this->set_file_offset(os->offset() + offset);
5241
5242   this->set_current_data_size(this->original_size_);
5243   this->finalize_data_size();
5244 }
5245
5246 template<bool big_endian>
5247 void
5248 Arm_input_section<big_endian>::do_write(Output_file* of)
5249 {
5250   // We have to write out the original section content.
5251   gold_assert(this->original_contents_ != NULL);
5252   of->write(this->offset(), this->original_contents_,
5253             this->original_size_);
5254
5255   // If this owns a stub table and it is not empty, write it.
5256   if (this->is_stub_table_owner() && !this->stub_table_->empty())
5257     this->stub_table_->write(of);
5258 }
5259
5260 // Finalize data size.
5261
5262 template<bool big_endian>
5263 void
5264 Arm_input_section<big_endian>::set_final_data_size()
5265 {
5266   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5267
5268   if (this->is_stub_table_owner())
5269     {
5270       this->stub_table_->finalize_data_size();
5271       off = align_address(off, this->stub_table_->addralign());
5272       off += this->stub_table_->data_size();
5273     }
5274   this->set_data_size(off);
5275 }
5276
5277 // Reset address and file offset.
5278
5279 template<bool big_endian>
5280 void
5281 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5282 {
5283   // Size of the original input section contents.
5284   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5285
5286   // If this is a stub table owner, account for the stub table size.
5287   if (this->is_stub_table_owner())
5288     {
5289       Stub_table<big_endian>* stub_table = this->stub_table_;
5290
5291       // Reset the stub table's address and file offset.  The
5292       // current data size for child will be updated after that.
5293       stub_table_->reset_address_and_file_offset();
5294       off = align_address(off, stub_table_->addralign());
5295       off += stub_table->current_data_size();
5296     }
5297
5298   this->set_current_data_size(off);
5299 }
5300
5301 // Arm_exidx_cantunwind methods.
5302
5303 // Write this to Output file OF for a fixed endianness.
5304
5305 template<bool big_endian>
5306 void
5307 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5308 {
5309   off_t offset = this->offset();
5310   const section_size_type oview_size = 8;
5311   unsigned char* const oview = of->get_output_view(offset, oview_size);
5312
5313   Output_section* os = this->relobj_->output_section(this->shndx_);
5314   gold_assert(os != NULL);
5315
5316   Arm_relobj<big_endian>* arm_relobj =
5317     Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5318   Arm_address output_offset =
5319     arm_relobj->get_output_section_offset(this->shndx_);
5320   Arm_address section_start;
5321   section_size_type section_size;
5322
5323   // Find out the end of the text section referred by this.
5324   if (output_offset != Arm_relobj<big_endian>::invalid_address)
5325     {
5326       section_start = os->address() + output_offset;
5327       const Arm_exidx_input_section* exidx_input_section =
5328         arm_relobj->exidx_input_section_by_link(this->shndx_);
5329       gold_assert(exidx_input_section != NULL);
5330       section_size =
5331         convert_to_section_size_type(exidx_input_section->text_size());
5332     }
5333   else
5334     {
5335       // Currently this only happens for a relaxed section.
5336       const Output_relaxed_input_section* poris =
5337         os->find_relaxed_input_section(this->relobj_, this->shndx_);
5338       gold_assert(poris != NULL);
5339       section_start = poris->address();
5340       section_size = convert_to_section_size_type(poris->data_size());
5341     }
5342
5343   // We always append this to the end of an EXIDX section.
5344   Arm_address output_address = section_start + section_size;
5345
5346   // Write out the entry.  The first word either points to the beginning
5347   // or after the end of a text section.  The second word is the special
5348   // EXIDX_CANTUNWIND value.
5349   uint32_t prel31_offset = output_address - this->address();
5350   if (Bits<31>::has_overflow32(offset))
5351     gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5352   elfcpp::Swap_unaligned<32, big_endian>::writeval(oview,
5353                                                    prel31_offset & 0x7fffffffU);
5354   elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4,
5355                                                    elfcpp::EXIDX_CANTUNWIND);
5356
5357   of->write_output_view(this->offset(), oview_size, oview);
5358 }
5359
5360 // Arm_exidx_merged_section methods.
5361
5362 // Constructor for Arm_exidx_merged_section.
5363 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5364 // SECTION_OFFSET_MAP points to a section offset map describing how
5365 // parts of the input section are mapped to output.  DELETED_BYTES is
5366 // the number of bytes deleted from the EXIDX input section.
5367
5368 Arm_exidx_merged_section::Arm_exidx_merged_section(
5369     const Arm_exidx_input_section& exidx_input_section,
5370     const Arm_exidx_section_offset_map& section_offset_map,
5371     uint32_t deleted_bytes)
5372   : Output_relaxed_input_section(exidx_input_section.relobj(),
5373                                  exidx_input_section.shndx(),
5374                                  exidx_input_section.addralign()),
5375     exidx_input_section_(exidx_input_section),
5376     section_offset_map_(section_offset_map)
5377 {
5378   // If we retain or discard the whole EXIDX input section,  we would
5379   // not be here.
5380   gold_assert(deleted_bytes != 0
5381               && deleted_bytes != this->exidx_input_section_.size());
5382
5383   // Fix size here so that we do not need to implement set_final_data_size.
5384   uint32_t size = exidx_input_section.size() - deleted_bytes;
5385   this->set_data_size(size);
5386   this->fix_data_size();
5387
5388   // Allocate buffer for section contents and build contents.
5389   this->section_contents_ = new unsigned char[size];
5390 }
5391
5392 // Build the contents of a merged EXIDX output section.
5393
5394 void
5395 Arm_exidx_merged_section::build_contents(
5396     const unsigned char* original_contents,
5397     section_size_type original_size)
5398 {
5399   // Go over spans of input offsets and write only those that are not
5400   // discarded.
5401   section_offset_type in_start = 0;
5402   section_offset_type out_start = 0;
5403   section_offset_type in_max =
5404     convert_types<section_offset_type>(original_size);
5405   section_offset_type out_max =
5406     convert_types<section_offset_type>(this->data_size());
5407   for (Arm_exidx_section_offset_map::const_iterator p =
5408         this->section_offset_map_.begin();
5409       p != this->section_offset_map_.end();
5410       ++p)
5411     {
5412       section_offset_type in_end = p->first;
5413       gold_assert(in_end >= in_start);
5414       section_offset_type out_end = p->second;
5415       size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5416       if (out_end != -1)
5417         {
5418           size_t out_chunk_size =
5419             convert_types<size_t>(out_end - out_start + 1);
5420
5421           gold_assert(out_chunk_size == in_chunk_size
5422                       && in_end < in_max && out_end < out_max);
5423
5424           memcpy(this->section_contents_ + out_start,
5425                  original_contents + in_start,
5426                  out_chunk_size);
5427           out_start += out_chunk_size;
5428         }
5429       in_start += in_chunk_size;
5430     }
5431 }
5432
5433 // Given an input OBJECT, an input section index SHNDX within that
5434 // object, and an OFFSET relative to the start of that input
5435 // section, return whether or not the corresponding offset within
5436 // the output section is known.  If this function returns true, it
5437 // sets *POUTPUT to the output offset.  The value -1 indicates that
5438 // this input offset is being discarded.
5439
5440 bool
5441 Arm_exidx_merged_section::do_output_offset(
5442     const Relobj* relobj,
5443     unsigned int shndx,
5444     section_offset_type offset,
5445     section_offset_type* poutput) const
5446 {
5447   // We only handle offsets for the original EXIDX input section.
5448   if (relobj != this->exidx_input_section_.relobj()
5449       || shndx != this->exidx_input_section_.shndx())
5450     return false;
5451
5452   section_offset_type section_size =
5453     convert_types<section_offset_type>(this->exidx_input_section_.size());
5454   if (offset < 0 || offset >= section_size)
5455     // Input offset is out of valid range.
5456     *poutput = -1;
5457   else
5458     {
5459       // We need to look up the section offset map to determine the output
5460       // offset.  Find the reference point in map that is first offset
5461       // bigger than or equal to this offset.
5462       Arm_exidx_section_offset_map::const_iterator p =
5463         this->section_offset_map_.lower_bound(offset);
5464
5465       // The section offset maps are build such that this should not happen if
5466       // input offset is in the valid range.
5467       gold_assert(p != this->section_offset_map_.end());
5468
5469       // We need to check if this is dropped.
5470      section_offset_type ref = p->first;
5471      section_offset_type mapped_ref = p->second;
5472
5473       if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5474         // Offset is present in output.
5475         *poutput = mapped_ref + (offset - ref);
5476       else
5477         // Offset is discarded owing to EXIDX entry merging.
5478         *poutput = -1;
5479     }
5480
5481   return true;
5482 }
5483
5484 // Write this to output file OF.
5485
5486 void
5487 Arm_exidx_merged_section::do_write(Output_file* of)
5488 {
5489   off_t offset = this->offset();
5490   const section_size_type oview_size = this->data_size();
5491   unsigned char* const oview = of->get_output_view(offset, oview_size);
5492
5493   Output_section* os = this->relobj()->output_section(this->shndx());
5494   gold_assert(os != NULL);
5495
5496   memcpy(oview, this->section_contents_, oview_size);
5497   of->write_output_view(this->offset(), oview_size, oview);
5498 }
5499
5500 // Arm_exidx_fixup methods.
5501
5502 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5503 // is not an EXIDX_CANTUNWIND entry already.  The new EXIDX_CANTUNWIND entry
5504 // points to the end of the last seen EXIDX section.
5505
5506 void
5507 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5508 {
5509   if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5510       && this->last_input_section_ != NULL)
5511     {
5512       Relobj* relobj = this->last_input_section_->relobj();
5513       unsigned int text_shndx = this->last_input_section_->link();
5514       Arm_exidx_cantunwind* cantunwind =
5515         new Arm_exidx_cantunwind(relobj, text_shndx);
5516       this->exidx_output_section_->add_output_section_data(cantunwind);
5517       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5518     }
5519 }
5520
5521 // Process an EXIDX section entry in input.  Return whether this entry
5522 // can be deleted in the output.  SECOND_WORD in the second word of the
5523 // EXIDX entry.
5524
5525 bool
5526 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5527 {
5528   bool delete_entry;
5529   if (second_word == elfcpp::EXIDX_CANTUNWIND)
5530     {
5531       // Merge if previous entry is also an EXIDX_CANTUNWIND.
5532       delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5533       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5534     }
5535   else if ((second_word & 0x80000000) != 0)
5536     {
5537       // Inlined unwinding data.  Merge if equal to previous.
5538       delete_entry = (merge_exidx_entries_
5539                       && this->last_unwind_type_ == UT_INLINED_ENTRY
5540                       && this->last_inlined_entry_ == second_word);
5541       this->last_unwind_type_ = UT_INLINED_ENTRY;
5542       this->last_inlined_entry_ = second_word;
5543     }
5544   else
5545     {
5546       // Normal table entry.  In theory we could merge these too,
5547       // but duplicate entries are likely to be much less common.
5548       delete_entry = false;
5549       this->last_unwind_type_ = UT_NORMAL_ENTRY;
5550     }
5551   return delete_entry;
5552 }
5553
5554 // Update the current section offset map during EXIDX section fix-up.
5555 // If there is no map, create one.  INPUT_OFFSET is the offset of a
5556 // reference point, DELETED_BYTES is the number of deleted by in the
5557 // section so far.  If DELETE_ENTRY is true, the reference point and
5558 // all offsets after the previous reference point are discarded.
5559
5560 void
5561 Arm_exidx_fixup::update_offset_map(
5562     section_offset_type input_offset,
5563     section_size_type deleted_bytes,
5564     bool delete_entry)
5565 {
5566   if (this->section_offset_map_ == NULL)
5567     this->section_offset_map_ = new Arm_exidx_section_offset_map();
5568   section_offset_type output_offset;
5569   if (delete_entry)
5570     output_offset = Arm_exidx_input_section::invalid_offset;
5571   else
5572     output_offset = input_offset - deleted_bytes;
5573   (*this->section_offset_map_)[input_offset] = output_offset;
5574 }
5575
5576 // Process EXIDX_INPUT_SECTION for EXIDX entry merging.  Return the number of
5577 // bytes deleted.  SECTION_CONTENTS points to the contents of the EXIDX
5578 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5579 // If some entries are merged, also store a pointer to a newly created
5580 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP.  The caller
5581 // owns the map and is responsible for releasing it after use.
5582
5583 template<bool big_endian>
5584 uint32_t
5585 Arm_exidx_fixup::process_exidx_section(
5586     const Arm_exidx_input_section* exidx_input_section,
5587     const unsigned char* section_contents,
5588     section_size_type section_size,
5589     Arm_exidx_section_offset_map** psection_offset_map)
5590 {
5591   Relobj* relobj = exidx_input_section->relobj();
5592   unsigned shndx = exidx_input_section->shndx();
5593
5594   if ((section_size % 8) != 0)
5595     {
5596       // Something is wrong with this section.  Better not touch it.
5597       gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5598                  relobj->name().c_str(), shndx);
5599       this->last_input_section_ = exidx_input_section;
5600       this->last_unwind_type_ = UT_NONE;
5601       return 0;
5602     }
5603
5604   uint32_t deleted_bytes = 0;
5605   bool prev_delete_entry = false;
5606   gold_assert(this->section_offset_map_ == NULL);
5607
5608   for (section_size_type i = 0; i < section_size; i += 8)
5609     {
5610       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5611       const Valtype* wv =
5612           reinterpret_cast<const Valtype*>(section_contents + i + 4);
5613       uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5614
5615       bool delete_entry = this->process_exidx_entry(second_word);
5616
5617       // Entry deletion causes changes in output offsets.  We use a std::map
5618       // to record these.  And entry (x, y) means input offset x
5619       // is mapped to output offset y.  If y is invalid_offset, then x is
5620       // dropped in the output.  Because of the way std::map::lower_bound
5621       // works, we record the last offset in a region w.r.t to keeping or
5622       // dropping.  If there is no entry (x0, y0) for an input offset x0,
5623       // the output offset y0 of it is determined by the output offset y1 of
5624       // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5625       // in the map.  If y1 is not -1, then y0 = y1 + x0 - x1.  Otherwise, y1
5626       // y0 is also -1.
5627       if (delete_entry != prev_delete_entry && i != 0)
5628         this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5629
5630       // Update total deleted bytes for this entry.
5631       if (delete_entry)
5632         deleted_bytes += 8;
5633
5634       prev_delete_entry = delete_entry;
5635     }
5636
5637   // If section offset map is not NULL, make an entry for the end of
5638   // section.
5639   if (this->section_offset_map_ != NULL)
5640     update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5641
5642   *psection_offset_map = this->section_offset_map_;
5643   this->section_offset_map_ = NULL;
5644   this->last_input_section_ = exidx_input_section;
5645
5646   // Set the first output text section so that we can link the EXIDX output
5647   // section to it.  Ignore any EXIDX input section that is completely merged.
5648   if (this->first_output_text_section_ == NULL
5649       && deleted_bytes != section_size)
5650     {
5651       unsigned int link = exidx_input_section->link();
5652       Output_section* os = relobj->output_section(link);
5653       gold_assert(os != NULL);
5654       this->first_output_text_section_ = os;
5655     }
5656
5657   return deleted_bytes;
5658 }
5659
5660 // Arm_output_section methods.
5661
5662 // Create a stub group for input sections from BEGIN to END.  OWNER
5663 // points to the input section to be the owner a new stub table.
5664
5665 template<bool big_endian>
5666 void
5667 Arm_output_section<big_endian>::create_stub_group(
5668   Input_section_list::const_iterator begin,
5669   Input_section_list::const_iterator end,
5670   Input_section_list::const_iterator owner,
5671   Target_arm<big_endian>* target,
5672   std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5673   const Task* task)
5674 {
5675   // We use a different kind of relaxed section in an EXIDX section.
5676   // The static casting from Output_relaxed_input_section to
5677   // Arm_input_section is invalid in an EXIDX section.  We are okay
5678   // because we should not be calling this for an EXIDX section.
5679   gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5680
5681   // Currently we convert ordinary input sections into relaxed sections only
5682   // at this point but we may want to support creating relaxed input section
5683   // very early.  So we check here to see if owner is already a relaxed
5684   // section.
5685
5686   Arm_input_section<big_endian>* arm_input_section;
5687   if (owner->is_relaxed_input_section())
5688     {
5689       arm_input_section =
5690         Arm_input_section<big_endian>::as_arm_input_section(
5691           owner->relaxed_input_section());
5692     }
5693   else
5694     {
5695       gold_assert(owner->is_input_section());
5696       // Create a new relaxed input section.  We need to lock the original
5697       // file.
5698       Task_lock_obj<Object> tl(task, owner->relobj());
5699       arm_input_section =
5700         target->new_arm_input_section(owner->relobj(), owner->shndx());
5701       new_relaxed_sections->push_back(arm_input_section);
5702     }
5703
5704   // Create a stub table.
5705   Stub_table<big_endian>* stub_table =
5706     target->new_stub_table(arm_input_section);
5707
5708   arm_input_section->set_stub_table(stub_table);
5709
5710   Input_section_list::const_iterator p = begin;
5711   Input_section_list::const_iterator prev_p;
5712
5713   // Look for input sections or relaxed input sections in [begin ... end].
5714   do
5715     {
5716       if (p->is_input_section() || p->is_relaxed_input_section())
5717         {
5718           // The stub table information for input sections live
5719           // in their objects.
5720           Arm_relobj<big_endian>* arm_relobj =
5721             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5722           arm_relobj->set_stub_table(p->shndx(), stub_table);
5723         }
5724       prev_p = p++;
5725     }
5726   while (prev_p != end);
5727 }
5728
5729 // Group input sections for stub generation.  GROUP_SIZE is roughly the limit
5730 // of stub groups.  We grow a stub group by adding input section until the
5731 // size is just below GROUP_SIZE.  The last input section will be converted
5732 // into a stub table.  If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5733 // input section after the stub table, effectively double the group size.
5734 //
5735 // This is similar to the group_sections() function in elf32-arm.c but is
5736 // implemented differently.
5737
5738 template<bool big_endian>
5739 void
5740 Arm_output_section<big_endian>::group_sections(
5741     section_size_type group_size,
5742     bool stubs_always_after_branch,
5743     Target_arm<big_endian>* target,
5744     const Task* task)
5745 {
5746   // States for grouping.
5747   typedef enum
5748   {
5749     // No group is being built.
5750     NO_GROUP,
5751     // A group is being built but the stub table is not found yet.
5752     // We keep group a stub group until the size is just under GROUP_SIZE.
5753     // The last input section in the group will be used as the stub table.
5754     FINDING_STUB_SECTION,
5755     // A group is being built and we have already found a stub table.
5756     // We enter this state to grow a stub group by adding input section
5757     // after the stub table.  This effectively doubles the group size.
5758     HAS_STUB_SECTION
5759   } State;
5760
5761   // Any newly created relaxed sections are stored here.
5762   std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5763
5764   State state = NO_GROUP;
5765   section_size_type off = 0;
5766   section_size_type group_begin_offset = 0;
5767   section_size_type group_end_offset = 0;
5768   section_size_type stub_table_end_offset = 0;
5769   Input_section_list::const_iterator group_begin =
5770     this->input_sections().end();
5771   Input_section_list::const_iterator stub_table =
5772     this->input_sections().end();
5773   Input_section_list::const_iterator group_end = this->input_sections().end();
5774   for (Input_section_list::const_iterator p = this->input_sections().begin();
5775        p != this->input_sections().end();
5776        ++p)
5777     {
5778       section_size_type section_begin_offset =
5779         align_address(off, p->addralign());
5780       section_size_type section_end_offset =
5781         section_begin_offset + p->data_size();
5782
5783       // Check to see if we should group the previously seen sections.
5784       switch (state)
5785         {
5786         case NO_GROUP:
5787           break;
5788
5789         case FINDING_STUB_SECTION:
5790           // Adding this section makes the group larger than GROUP_SIZE.
5791           if (section_end_offset - group_begin_offset >= group_size)
5792             {
5793               if (stubs_always_after_branch)
5794                 {
5795                   gold_assert(group_end != this->input_sections().end());
5796                   this->create_stub_group(group_begin, group_end, group_end,
5797                                           target, &new_relaxed_sections,
5798                                           task);
5799                   state = NO_GROUP;
5800                 }
5801               else
5802                 {
5803                   // But wait, there's more!  Input sections up to
5804                   // stub_group_size bytes after the stub table can be
5805                   // handled by it too.
5806                   state = HAS_STUB_SECTION;
5807                   stub_table = group_end;
5808                   stub_table_end_offset = group_end_offset;
5809                 }
5810             }
5811             break;
5812
5813         case HAS_STUB_SECTION:
5814           // Adding this section makes the post stub-section group larger
5815           // than GROUP_SIZE.
5816           if (section_end_offset - stub_table_end_offset >= group_size)
5817            {
5818              gold_assert(group_end != this->input_sections().end());
5819              this->create_stub_group(group_begin, group_end, stub_table,
5820                                      target, &new_relaxed_sections, task);
5821              state = NO_GROUP;
5822            }
5823            break;
5824
5825           default:
5826             gold_unreachable();
5827         }
5828
5829       // If we see an input section and currently there is no group, start
5830       // a new one.  Skip any empty sections.  We look at the data size
5831       // instead of calling p->relobj()->section_size() to avoid locking.
5832       if ((p->is_input_section() || p->is_relaxed_input_section())
5833           && (p->data_size() != 0))
5834         {
5835           if (state == NO_GROUP)
5836             {
5837               state = FINDING_STUB_SECTION;
5838               group_begin = p;
5839               group_begin_offset = section_begin_offset;
5840             }
5841
5842           // Keep track of the last input section seen.
5843           group_end = p;
5844           group_end_offset = section_end_offset;
5845         }
5846
5847       off = section_end_offset;
5848     }
5849
5850   // Create a stub group for any ungrouped sections.
5851   if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5852     {
5853       gold_assert(group_end != this->input_sections().end());
5854       this->create_stub_group(group_begin, group_end,
5855                               (state == FINDING_STUB_SECTION
5856                                ? group_end
5857                                : stub_table),
5858                                target, &new_relaxed_sections, task);
5859     }
5860
5861   // Convert input section into relaxed input section in a batch.
5862   if (!new_relaxed_sections.empty())
5863     this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5864
5865   // Update the section offsets
5866   for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5867     {
5868       Arm_relobj<big_endian>* arm_relobj =
5869         Arm_relobj<big_endian>::as_arm_relobj(
5870           new_relaxed_sections[i]->relobj());
5871       unsigned int shndx = new_relaxed_sections[i]->shndx();
5872       // Tell Arm_relobj that this input section is converted.
5873       arm_relobj->convert_input_section_to_relaxed_section(shndx);
5874     }
5875 }
5876
5877 // Append non empty text sections in this to LIST in ascending
5878 // order of their position in this.
5879
5880 template<bool big_endian>
5881 void
5882 Arm_output_section<big_endian>::append_text_sections_to_list(
5883     Text_section_list* list)
5884 {
5885   gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5886
5887   for (Input_section_list::const_iterator p = this->input_sections().begin();
5888        p != this->input_sections().end();
5889        ++p)
5890     {
5891       // We only care about plain or relaxed input sections.  We also
5892       // ignore any merged sections.
5893       if (p->is_input_section() || p->is_relaxed_input_section())
5894         list->push_back(Text_section_list::value_type(p->relobj(),
5895                                                       p->shndx()));
5896     }
5897 }
5898
5899 template<bool big_endian>
5900 void
5901 Arm_output_section<big_endian>::fix_exidx_coverage(
5902     Layout* layout,
5903     const Text_section_list& sorted_text_sections,
5904     Symbol_table* symtab,
5905     bool merge_exidx_entries,
5906     const Task* task)
5907 {
5908   // We should only do this for the EXIDX output section.
5909   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5910
5911   // We don't want the relaxation loop to undo these changes, so we discard
5912   // the current saved states and take another one after the fix-up.
5913   this->discard_states();
5914
5915   // Remove all input sections.
5916   uint64_t address = this->address();
5917   typedef std::list<Output_section::Input_section> Input_section_list;
5918   Input_section_list input_sections;
5919   this->reset_address_and_file_offset();
5920   this->get_input_sections(address, std::string(""), &input_sections);
5921
5922   if (!this->input_sections().empty())
5923     gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5924
5925   // Go through all the known input sections and record them.
5926   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5927   typedef Unordered_map<Section_id, const Output_section::Input_section*,
5928                         Section_id_hash> Text_to_exidx_map;
5929   Text_to_exidx_map text_to_exidx_map;
5930   for (Input_section_list::const_iterator p = input_sections.begin();
5931        p != input_sections.end();
5932        ++p)
5933     {
5934       // This should never happen.  At this point, we should only see
5935       // plain EXIDX input sections.
5936       gold_assert(!p->is_relaxed_input_section());
5937       text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5938     }
5939
5940   Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5941
5942   // Go over the sorted text sections.
5943   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5944   Section_id_set processed_input_sections;
5945   for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5946        p != sorted_text_sections.end();
5947        ++p)
5948     {
5949       Relobj* relobj = p->first;
5950       unsigned int shndx = p->second;
5951
5952       Arm_relobj<big_endian>* arm_relobj =
5953          Arm_relobj<big_endian>::as_arm_relobj(relobj);
5954       const Arm_exidx_input_section* exidx_input_section =
5955          arm_relobj->exidx_input_section_by_link(shndx);
5956
5957       // If this text section has no EXIDX section or if the EXIDX section
5958       // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5959       // of the last seen EXIDX section.
5960       if (exidx_input_section == NULL || exidx_input_section->has_errors())
5961         {
5962           exidx_fixup.add_exidx_cantunwind_as_needed();
5963           continue;
5964         }
5965
5966       Relobj* exidx_relobj = exidx_input_section->relobj();
5967       unsigned int exidx_shndx = exidx_input_section->shndx();
5968       Section_id sid(exidx_relobj, exidx_shndx);
5969       Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5970       if (iter == text_to_exidx_map.end())
5971         {
5972           // This is odd.  We have not seen this EXIDX input section before.
5973           // We cannot do fix-up.  If we saw a SECTIONS clause in a script,
5974           // issue a warning instead.  We assume the user knows what he
5975           // or she is doing.  Otherwise, this is an error.
5976           if (layout->script_options()->saw_sections_clause())
5977             gold_warning(_("unwinding may not work because EXIDX input section"
5978                            " %u of %s is not in EXIDX output section"),
5979                          exidx_shndx, exidx_relobj->name().c_str());
5980           else
5981             gold_error(_("unwinding may not work because EXIDX input section"
5982                          " %u of %s is not in EXIDX output section"),
5983                        exidx_shndx, exidx_relobj->name().c_str());
5984
5985           exidx_fixup.add_exidx_cantunwind_as_needed();
5986           continue;
5987         }
5988
5989       // We need to access the contents of the EXIDX section, lock the
5990       // object here.
5991       Task_lock_obj<Object> tl(task, exidx_relobj);
5992       section_size_type exidx_size;
5993       const unsigned char* exidx_contents =
5994         exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5995
5996       // Fix up coverage and append input section to output data list.
5997       Arm_exidx_section_offset_map* section_offset_map = NULL;
5998       uint32_t deleted_bytes =
5999         exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
6000                                                       exidx_contents,
6001                                                       exidx_size,
6002                                                       &section_offset_map);
6003
6004       if (deleted_bytes == exidx_input_section->size())
6005         {
6006           // The whole EXIDX section got merged.  Remove it from output.
6007           gold_assert(section_offset_map == NULL);
6008           exidx_relobj->set_output_section(exidx_shndx, NULL);
6009
6010           // All local symbols defined in this input section will be dropped.
6011           // We need to adjust output local symbol count.
6012           arm_relobj->set_output_local_symbol_count_needs_update();
6013         }
6014       else if (deleted_bytes > 0)
6015         {
6016           // Some entries are merged.  We need to convert this EXIDX input
6017           // section into a relaxed section.
6018           gold_assert(section_offset_map != NULL);
6019
6020           Arm_exidx_merged_section* merged_section =
6021             new Arm_exidx_merged_section(*exidx_input_section,
6022                                          *section_offset_map, deleted_bytes);
6023           merged_section->build_contents(exidx_contents, exidx_size);
6024
6025           const std::string secname = exidx_relobj->section_name(exidx_shndx);
6026           this->add_relaxed_input_section(layout, merged_section, secname);
6027           arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
6028
6029           // All local symbols defined in discarded portions of this input
6030           // section will be dropped.  We need to adjust output local symbol
6031           // count.
6032           arm_relobj->set_output_local_symbol_count_needs_update();
6033         }
6034       else
6035         {
6036           // Just add back the EXIDX input section.
6037           gold_assert(section_offset_map == NULL);
6038           const Output_section::Input_section* pis = iter->second;
6039           gold_assert(pis->is_input_section());
6040           this->add_script_input_section(*pis);
6041         }
6042
6043       processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
6044     }
6045
6046   // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
6047   exidx_fixup.add_exidx_cantunwind_as_needed();
6048
6049   // Remove any known EXIDX input sections that are not processed.
6050   for (Input_section_list::const_iterator p = input_sections.begin();
6051        p != input_sections.end();
6052        ++p)
6053     {
6054       if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
6055           == processed_input_sections.end())
6056         {
6057           // We discard a known EXIDX section because its linked
6058           // text section has been folded by ICF.  We also discard an
6059           // EXIDX section with error, the output does not matter in this
6060           // case.  We do this to avoid triggering asserts.
6061           Arm_relobj<big_endian>* arm_relobj =
6062             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6063           const Arm_exidx_input_section* exidx_input_section =
6064             arm_relobj->exidx_input_section_by_shndx(p->shndx());
6065           gold_assert(exidx_input_section != NULL);
6066           if (!exidx_input_section->has_errors())
6067             {
6068               unsigned int text_shndx = exidx_input_section->link();
6069               gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
6070             }
6071
6072           // Remove this from link.  We also need to recount the
6073           // local symbols.
6074           p->relobj()->set_output_section(p->shndx(), NULL);
6075           arm_relobj->set_output_local_symbol_count_needs_update();
6076         }
6077     }
6078
6079   // Link exidx output section to the first seen output section and
6080   // set correct entry size.
6081   this->set_link_section(exidx_fixup.first_output_text_section());
6082   this->set_entsize(8);
6083
6084   // Make changes permanent.
6085   this->save_states();
6086   this->set_section_offsets_need_adjustment();
6087 }
6088
6089 // Link EXIDX output sections to text output sections.
6090
6091 template<bool big_endian>
6092 void
6093 Arm_output_section<big_endian>::set_exidx_section_link()
6094 {
6095   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
6096   if (!this->input_sections().empty())
6097     {
6098       Input_section_list::const_iterator p = this->input_sections().begin();
6099       Arm_relobj<big_endian>* arm_relobj =
6100         Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6101       unsigned exidx_shndx = p->shndx();
6102       const Arm_exidx_input_section* exidx_input_section =
6103         arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6104       gold_assert(exidx_input_section != NULL);
6105       unsigned int text_shndx = exidx_input_section->link();
6106       Output_section* os = arm_relobj->output_section(text_shndx);
6107       this->set_link_section(os);
6108     }
6109 }
6110
6111 // Arm_relobj methods.
6112
6113 // Determine if an input section is scannable for stub processing.  SHDR is
6114 // the header of the section and SHNDX is the section index.  OS is the output
6115 // section for the input section and SYMTAB is the global symbol table used to
6116 // look up ICF information.
6117
6118 template<bool big_endian>
6119 bool
6120 Arm_relobj<big_endian>::section_is_scannable(
6121     const elfcpp::Shdr<32, big_endian>& shdr,
6122     unsigned int shndx,
6123     const Output_section* os,
6124     const Symbol_table* symtab)
6125 {
6126   // Skip any empty sections, unallocated sections or sections whose
6127   // type are not SHT_PROGBITS.
6128   if (shdr.get_sh_size() == 0
6129       || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6130       || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6131     return false;
6132
6133   // Skip any discarded or ICF'ed sections.
6134   if (os == NULL || symtab->is_section_folded(this, shndx))
6135     return false;
6136
6137   // If this requires special offset handling, check to see if it is
6138   // a relaxed section.  If this is not, then it is a merged section that
6139   // we cannot handle.
6140   if (this->is_output_section_offset_invalid(shndx))
6141     {
6142       const Output_relaxed_input_section* poris =
6143         os->find_relaxed_input_section(this, shndx);
6144       if (poris == NULL)
6145         return false;
6146     }
6147
6148   return true;
6149 }
6150
6151 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6152 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6153
6154 template<bool big_endian>
6155 bool
6156 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6157     const elfcpp::Shdr<32, big_endian>& shdr,
6158     const Relobj::Output_sections& out_sections,
6159     const Symbol_table* symtab,
6160     const unsigned char* pshdrs)
6161 {
6162   unsigned int sh_type = shdr.get_sh_type();
6163   if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6164     return false;
6165
6166   // Ignore empty section.
6167   off_t sh_size = shdr.get_sh_size();
6168   if (sh_size == 0)
6169     return false;
6170
6171   // Ignore reloc section with unexpected symbol table.  The
6172   // error will be reported in the final link.
6173   if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6174     return false;
6175
6176   unsigned int reloc_size;
6177   if (sh_type == elfcpp::SHT_REL)
6178     reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6179   else
6180     reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6181
6182   // Ignore reloc section with unexpected entsize or uneven size.
6183   // The error will be reported in the final link.
6184   if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6185     return false;
6186
6187   // Ignore reloc section with bad info.  This error will be
6188   // reported in the final link.
6189   unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6190   if (index >= this->shnum())
6191     return false;
6192
6193   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6194   const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6195   return this->section_is_scannable(text_shdr, index,
6196                                    out_sections[index], symtab);
6197 }
6198
6199 // Return the output address of either a plain input section or a relaxed
6200 // input section.  SHNDX is the section index.  We define and use this
6201 // instead of calling Output_section::output_address because that is slow
6202 // for large output.
6203
6204 template<bool big_endian>
6205 Arm_address
6206 Arm_relobj<big_endian>::simple_input_section_output_address(
6207     unsigned int shndx,
6208     Output_section* os)
6209 {
6210   if (this->is_output_section_offset_invalid(shndx))
6211     {
6212       const Output_relaxed_input_section* poris =
6213         os->find_relaxed_input_section(this, shndx);
6214       // We do not handle merged sections here.
6215       gold_assert(poris != NULL);
6216       return poris->address();
6217     }
6218   else
6219     return os->address() + this->get_output_section_offset(shndx);
6220 }
6221
6222 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6223 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6224
6225 template<bool big_endian>
6226 bool
6227 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6228     const elfcpp::Shdr<32, big_endian>& shdr,
6229     unsigned int shndx,
6230     Output_section* os,
6231     const Symbol_table* symtab)
6232 {
6233   if (!this->section_is_scannable(shdr, shndx, os, symtab))
6234     return false;
6235
6236   // If the section does not cross any 4K-boundaries, it does not need to
6237   // be scanned.
6238   Arm_address address = this->simple_input_section_output_address(shndx, os);
6239   if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6240     return false;
6241
6242   return true;
6243 }
6244
6245 // Scan a section for Cortex-A8 workaround.
6246
6247 template<bool big_endian>
6248 void
6249 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6250     const elfcpp::Shdr<32, big_endian>& shdr,
6251     unsigned int shndx,
6252     Output_section* os,
6253     Target_arm<big_endian>* arm_target)
6254 {
6255   // Look for the first mapping symbol in this section.  It should be
6256   // at (shndx, 0).
6257   Mapping_symbol_position section_start(shndx, 0);
6258   typename Mapping_symbols_info::const_iterator p =
6259     this->mapping_symbols_info_.lower_bound(section_start);
6260
6261   // There are no mapping symbols for this section.  Treat it as a data-only
6262   // section.
6263   if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6264     return;
6265
6266   Arm_address output_address =
6267     this->simple_input_section_output_address(shndx, os);
6268
6269   // Get the section contents.
6270   section_size_type input_view_size = 0;
6271   const unsigned char* input_view =
6272     this->section_contents(shndx, &input_view_size, false);
6273
6274   // We need to go through the mapping symbols to determine what to
6275   // scan.  There are two reasons.  First, we should look at THUMB code and
6276   // THUMB code only.  Second, we only want to look at the 4K-page boundary
6277   // to speed up the scanning.
6278
6279   while (p != this->mapping_symbols_info_.end()
6280         && p->first.first == shndx)
6281     {
6282       typename Mapping_symbols_info::const_iterator next =
6283         this->mapping_symbols_info_.upper_bound(p->first);
6284
6285       // Only scan part of a section with THUMB code.
6286       if (p->second == 't')
6287         {
6288           // Determine the end of this range.
6289           section_size_type span_start =
6290             convert_to_section_size_type(p->first.second);
6291           section_size_type span_end;
6292           if (next != this->mapping_symbols_info_.end()
6293               && next->first.first == shndx)
6294             span_end = convert_to_section_size_type(next->first.second);
6295           else
6296             span_end = convert_to_section_size_type(shdr.get_sh_size());
6297
6298           if (((span_start + output_address) & ~0xfffUL)
6299               != ((span_end + output_address - 1) & ~0xfffUL))
6300             {
6301               arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6302                                                           span_start, span_end,
6303                                                           input_view,
6304                                                           output_address);
6305             }
6306         }
6307
6308       p = next;
6309     }
6310 }
6311
6312 // Scan relocations for stub generation.
6313
6314 template<bool big_endian>
6315 void
6316 Arm_relobj<big_endian>::scan_sections_for_stubs(
6317     Target_arm<big_endian>* arm_target,
6318     const Symbol_table* symtab,
6319     const Layout* layout)
6320 {
6321   unsigned int shnum = this->shnum();
6322   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6323
6324   // Read the section headers.
6325   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6326                                                shnum * shdr_size,
6327                                                true, true);
6328
6329   // To speed up processing, we set up hash tables for fast lookup of
6330   // input offsets to output addresses.
6331   this->initialize_input_to_output_maps();
6332
6333   const Relobj::Output_sections& out_sections(this->output_sections());
6334
6335   Relocate_info<32, big_endian> relinfo;
6336   relinfo.symtab = symtab;
6337   relinfo.layout = layout;
6338   relinfo.object = this;
6339
6340   // Do relocation stubs scanning.
6341   const unsigned char* p = pshdrs + shdr_size;
6342   for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6343     {
6344       const elfcpp::Shdr<32, big_endian> shdr(p);
6345       if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6346                                                   pshdrs))
6347         {
6348           unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6349           Arm_address output_offset = this->get_output_section_offset(index);
6350           Arm_address output_address;
6351           if (output_offset != invalid_address)
6352             output_address = out_sections[index]->address() + output_offset;
6353           else
6354             {
6355               // Currently this only happens for a relaxed section.
6356               const Output_relaxed_input_section* poris =
6357               out_sections[index]->find_relaxed_input_section(this, index);
6358               gold_assert(poris != NULL);
6359               output_address = poris->address();
6360             }
6361
6362           // Get the relocations.
6363           const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6364                                                         shdr.get_sh_size(),
6365                                                         true, false);
6366
6367           // Get the section contents.  This does work for the case in which
6368           // we modify the contents of an input section.  We need to pass the
6369           // output view under such circumstances.
6370           section_size_type input_view_size = 0;
6371           const unsigned char* input_view =
6372             this->section_contents(index, &input_view_size, false);
6373
6374           relinfo.reloc_shndx = i;
6375           relinfo.data_shndx = index;
6376           unsigned int sh_type = shdr.get_sh_type();
6377           unsigned int reloc_size;
6378           if (sh_type == elfcpp::SHT_REL)
6379             reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6380           else
6381             reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6382
6383           Output_section* os = out_sections[index];
6384           arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6385                                              shdr.get_sh_size() / reloc_size,
6386                                              os,
6387                                              output_offset == invalid_address,
6388                                              input_view, output_address,
6389                                              input_view_size);
6390         }
6391     }
6392
6393   // Do Cortex-A8 erratum stubs scanning.  This has to be done for a section
6394   // after its relocation section, if there is one, is processed for
6395   // relocation stubs.  Merging this loop with the one above would have been
6396   // complicated since we would have had to make sure that relocation stub
6397   // scanning is done first.
6398   if (arm_target->fix_cortex_a8())
6399     {
6400       const unsigned char* p = pshdrs + shdr_size;
6401       for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6402         {
6403           const elfcpp::Shdr<32, big_endian> shdr(p);
6404           if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6405                                                           out_sections[i],
6406                                                           symtab))
6407             this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6408                                                      arm_target);
6409         }
6410     }
6411
6412   // After we've done the relocations, we release the hash tables,
6413   // since we no longer need them.
6414   this->free_input_to_output_maps();
6415 }
6416
6417 // Count the local symbols.  The ARM backend needs to know if a symbol
6418 // is a THUMB function or not.  For global symbols, it is easy because
6419 // the Symbol object keeps the ELF symbol type.  For local symbol it is
6420 // harder because we cannot access this information.   So we override the
6421 // do_count_local_symbol in parent and scan local symbols to mark
6422 // THUMB functions.  This is not the most efficient way but I do not want to
6423 // slow down other ports by calling a per symbol target hook inside
6424 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6425
6426 template<bool big_endian>
6427 void
6428 Arm_relobj<big_endian>::do_count_local_symbols(
6429     Stringpool_template<char>* pool,
6430     Stringpool_template<char>* dynpool)
6431 {
6432   // We need to fix-up the values of any local symbols whose type are
6433   // STT_ARM_TFUNC.
6434
6435   // Ask parent to count the local symbols.
6436   Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6437   const unsigned int loccount = this->local_symbol_count();
6438   if (loccount == 0)
6439     return;
6440
6441   // Initialize the thumb function bit-vector.
6442   std::vector<bool> empty_vector(loccount, false);
6443   this->local_symbol_is_thumb_function_.swap(empty_vector);
6444
6445   // Read the symbol table section header.
6446   const unsigned int symtab_shndx = this->symtab_shndx();
6447   elfcpp::Shdr<32, big_endian>
6448       symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6449   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6450
6451   // Read the local symbols.
6452   const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6453   gold_assert(loccount == symtabshdr.get_sh_info());
6454   off_t locsize = loccount * sym_size;
6455   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6456                                               locsize, true, true);
6457
6458   // For mapping symbol processing, we need to read the symbol names.
6459   unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6460   if (strtab_shndx >= this->shnum())
6461     {
6462       this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6463       return;
6464     }
6465
6466   elfcpp::Shdr<32, big_endian>
6467     strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6468   if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6469     {
6470       this->error(_("symbol table name section has wrong type: %u"),
6471                   static_cast<unsigned int>(strtabshdr.get_sh_type()));
6472       return;
6473     }
6474   const char* pnames =
6475     reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6476                                                  strtabshdr.get_sh_size(),
6477                                                  false, false));
6478
6479   // Loop over the local symbols and mark any local symbols pointing
6480   // to THUMB functions.
6481
6482   // Skip the first dummy symbol.
6483   psyms += sym_size;
6484   typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6485     this->local_values();
6486   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6487     {
6488       elfcpp::Sym<32, big_endian> sym(psyms);
6489       elfcpp::STT st_type = sym.get_st_type();
6490       Symbol_value<32>& lv((*plocal_values)[i]);
6491       Arm_address input_value = lv.input_value();
6492
6493       // Check to see if this is a mapping symbol.
6494       const char* sym_name = pnames + sym.get_st_name();
6495       if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6496         {
6497           bool is_ordinary;
6498           unsigned int input_shndx =
6499             this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6500           gold_assert(is_ordinary);
6501
6502           // Strip of LSB in case this is a THUMB symbol.
6503           Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6504           this->mapping_symbols_info_[msp] = sym_name[1];
6505         }
6506
6507       if (st_type == elfcpp::STT_ARM_TFUNC
6508           || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6509         {
6510           // This is a THUMB function.  Mark this and canonicalize the
6511           // symbol value by setting LSB.
6512           this->local_symbol_is_thumb_function_[i] = true;
6513           if ((input_value & 1) == 0)
6514             lv.set_input_value(input_value | 1);
6515         }
6516     }
6517 }
6518
6519 // Relocate sections.
6520 template<bool big_endian>
6521 void
6522 Arm_relobj<big_endian>::do_relocate_sections(
6523     const Symbol_table* symtab,
6524     const Layout* layout,
6525     const unsigned char* pshdrs,
6526     Output_file* of,
6527     typename Sized_relobj_file<32, big_endian>::Views* pviews)
6528 {
6529   // Call parent to relocate sections.
6530   Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6531                                                           pshdrs, of, pviews);
6532
6533   // We do not generate stubs if doing a relocatable link.
6534   if (parameters->options().relocatable())
6535     return;
6536
6537   // Relocate stub tables.
6538   unsigned int shnum = this->shnum();
6539
6540   Target_arm<big_endian>* arm_target =
6541     Target_arm<big_endian>::default_target();
6542
6543   Relocate_info<32, big_endian> relinfo;
6544   relinfo.symtab = symtab;
6545   relinfo.layout = layout;
6546   relinfo.object = this;
6547
6548   for (unsigned int i = 1; i < shnum; ++i)
6549     {
6550       Arm_input_section<big_endian>* arm_input_section =
6551         arm_target->find_arm_input_section(this, i);
6552
6553       if (arm_input_section != NULL
6554           && arm_input_section->is_stub_table_owner()
6555           && !arm_input_section->stub_table()->empty())
6556         {
6557           // We cannot discard a section if it owns a stub table.
6558           Output_section* os = this->output_section(i);
6559           gold_assert(os != NULL);
6560
6561           relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6562           relinfo.reloc_shdr = NULL;
6563           relinfo.data_shndx = i;
6564           relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6565
6566           gold_assert((*pviews)[i].view != NULL);
6567
6568           // We are passed the output section view.  Adjust it to cover the
6569           // stub table only.
6570           Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6571           gold_assert((stub_table->address() >= (*pviews)[i].address)
6572                       && ((stub_table->address() + stub_table->data_size())
6573                           <= (*pviews)[i].address + (*pviews)[i].view_size));
6574
6575           off_t offset = stub_table->address() - (*pviews)[i].address;
6576           unsigned char* view = (*pviews)[i].view + offset;
6577           Arm_address address = stub_table->address();
6578           section_size_type view_size = stub_table->data_size();
6579
6580           stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6581                                      view_size);
6582         }
6583
6584       // Apply Cortex A8 workaround if applicable.
6585       if (this->section_has_cortex_a8_workaround(i))
6586         {
6587           unsigned char* view = (*pviews)[i].view;
6588           Arm_address view_address = (*pviews)[i].address;
6589           section_size_type view_size = (*pviews)[i].view_size;
6590           Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6591
6592           // Adjust view to cover section.
6593           Output_section* os = this->output_section(i);
6594           gold_assert(os != NULL);
6595           Arm_address section_address =
6596             this->simple_input_section_output_address(i, os);
6597           uint64_t section_size = this->section_size(i);
6598
6599           gold_assert(section_address >= view_address
6600                       && ((section_address + section_size)
6601                           <= (view_address + view_size)));
6602
6603           unsigned char* section_view = view + (section_address - view_address);
6604
6605           // Apply the Cortex-A8 workaround to the output address range
6606           // corresponding to this input section.
6607           stub_table->apply_cortex_a8_workaround_to_address_range(
6608               arm_target,
6609               section_view,
6610               section_address,
6611               section_size);
6612         }
6613     }
6614 }
6615
6616 // Find the linked text section of an EXIDX section by looking at the first
6617 // relocation.  4.4.1 of the EHABI specifications says that an EXIDX section
6618 // must be linked to its associated code section via the sh_link field of
6619 // its section header.  However, some tools are broken and the link is not
6620 // always set.  LD just drops such an EXIDX section silently, causing the
6621 // associated code not unwindabled.   Here we try a little bit harder to
6622 // discover the linked code section.
6623 //
6624 // PSHDR points to the section header of a relocation section of an EXIDX
6625 // section.  If we can find a linked text section, return true and
6626 // store the text section index in the location PSHNDX.  Otherwise
6627 // return false.
6628
6629 template<bool big_endian>
6630 bool
6631 Arm_relobj<big_endian>::find_linked_text_section(
6632     const unsigned char* pshdr,
6633     const unsigned char* psyms,
6634     unsigned int* pshndx)
6635 {
6636   elfcpp::Shdr<32, big_endian> shdr(pshdr);
6637
6638   // If there is no relocation, we cannot find the linked text section.
6639   size_t reloc_size;
6640   if (shdr.get_sh_type() == elfcpp::SHT_REL)
6641       reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6642   else
6643       reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6644   size_t reloc_count = shdr.get_sh_size() / reloc_size;
6645
6646   // Get the relocations.
6647   const unsigned char* prelocs =
6648       this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6649
6650   // Find the REL31 relocation for the first word of the first EXIDX entry.
6651   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6652     {
6653       Arm_address r_offset;
6654       typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6655       if (shdr.get_sh_type() == elfcpp::SHT_REL)
6656         {
6657           typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6658           r_info = reloc.get_r_info();
6659           r_offset = reloc.get_r_offset();
6660         }
6661       else
6662         {
6663           typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6664           r_info = reloc.get_r_info();
6665           r_offset = reloc.get_r_offset();
6666         }
6667
6668       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6669       if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6670         continue;
6671
6672       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6673       if (r_sym == 0
6674           || r_sym >= this->local_symbol_count()
6675           || r_offset != 0)
6676         continue;
6677
6678       // This is the relocation for the first word of the first EXIDX entry.
6679       // We expect to see a local section symbol.
6680       const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6681       elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6682       if (sym.get_st_type() == elfcpp::STT_SECTION)
6683         {
6684           bool is_ordinary;
6685           *pshndx =
6686             this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6687           gold_assert(is_ordinary);
6688           return true;
6689         }
6690       else
6691         return false;
6692     }
6693
6694   return false;
6695 }
6696
6697 // Make an EXIDX input section object for an EXIDX section whose index is
6698 // SHNDX.  SHDR is the section header of the EXIDX section and TEXT_SHNDX
6699 // is the section index of the linked text section.
6700
6701 template<bool big_endian>
6702 void
6703 Arm_relobj<big_endian>::make_exidx_input_section(
6704     unsigned int shndx,
6705     const elfcpp::Shdr<32, big_endian>& shdr,
6706     unsigned int text_shndx,
6707     const elfcpp::Shdr<32, big_endian>& text_shdr)
6708 {
6709   // Create an Arm_exidx_input_section object for this EXIDX section.
6710   Arm_exidx_input_section* exidx_input_section =
6711     new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6712                                 shdr.get_sh_addralign(),
6713                                 text_shdr.get_sh_size());
6714
6715   gold_assert(this->exidx_section_map_[shndx] == NULL);
6716   this->exidx_section_map_[shndx] = exidx_input_section;
6717
6718   if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6719     {
6720       gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6721                  this->section_name(shndx).c_str(), shndx, text_shndx,
6722                  this->name().c_str());
6723       exidx_input_section->set_has_errors();
6724     }
6725   else if (this->exidx_section_map_[text_shndx] != NULL)
6726     {
6727       unsigned other_exidx_shndx =
6728         this->exidx_section_map_[text_shndx]->shndx();
6729       gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6730                    "%s(%u) in %s"),
6731                  this->section_name(shndx).c_str(), shndx,
6732                  this->section_name(other_exidx_shndx).c_str(),
6733                  other_exidx_shndx, this->section_name(text_shndx).c_str(),
6734                  text_shndx, this->name().c_str());
6735       exidx_input_section->set_has_errors();
6736     }
6737   else
6738      this->exidx_section_map_[text_shndx] = exidx_input_section;
6739
6740   // Check section flags of text section.
6741   if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6742     {
6743       gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6744                    " in %s"),
6745                  this->section_name(shndx).c_str(), shndx,
6746                  this->section_name(text_shndx).c_str(), text_shndx,
6747                  this->name().c_str());
6748       exidx_input_section->set_has_errors();
6749     }
6750   else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6751     // I would like to make this an error but currently ld just ignores
6752     // this.
6753     gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6754                    "%s(%u) in %s"),
6755                  this->section_name(shndx).c_str(), shndx,
6756                  this->section_name(text_shndx).c_str(), text_shndx,
6757                  this->name().c_str());
6758 }
6759
6760 // Read the symbol information.
6761
6762 template<bool big_endian>
6763 void
6764 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6765 {
6766   // Call parent class to read symbol information.
6767   this->base_read_symbols(sd);
6768
6769   // If this input file is a binary file, it has no processor
6770   // specific flags and attributes section.
6771   Input_file::Format format = this->input_file()->format();
6772   if (format != Input_file::FORMAT_ELF)
6773     {
6774       gold_assert(format == Input_file::FORMAT_BINARY);
6775       this->merge_flags_and_attributes_ = false;
6776       return;
6777     }
6778
6779   // Read processor-specific flags in ELF file header.
6780   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6781                                               elfcpp::Elf_sizes<32>::ehdr_size,
6782                                               true, false);
6783   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6784   this->processor_specific_flags_ = ehdr.get_e_flags();
6785
6786   // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6787   // sections.
6788   std::vector<unsigned int> deferred_exidx_sections;
6789   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6790   const unsigned char* pshdrs = sd->section_headers->data();
6791   const unsigned char* ps = pshdrs + shdr_size;
6792   bool must_merge_flags_and_attributes = false;
6793   for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6794     {
6795       elfcpp::Shdr<32, big_endian> shdr(ps);
6796
6797       // Sometimes an object has no contents except the section name string
6798       // table and an empty symbol table with the undefined symbol.  We
6799       // don't want to merge processor-specific flags from such an object.
6800       if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6801         {
6802           // Symbol table is not empty.
6803           const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6804              elfcpp::Elf_sizes<32>::sym_size;
6805           if (shdr.get_sh_size() > sym_size)
6806             must_merge_flags_and_attributes = true;
6807         }
6808       else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6809         // If this is neither an empty symbol table nor a string table,
6810         // be conservative.
6811         must_merge_flags_and_attributes = true;
6812
6813       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6814         {
6815           gold_assert(this->attributes_section_data_ == NULL);
6816           section_offset_type section_offset = shdr.get_sh_offset();
6817           section_size_type section_size =
6818             convert_to_section_size_type(shdr.get_sh_size());
6819           const unsigned char* view =
6820              this->get_view(section_offset, section_size, true, false);
6821           this->attributes_section_data_ =
6822             new Attributes_section_data(view, section_size);
6823         }
6824       else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6825         {
6826           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6827           if (text_shndx == elfcpp::SHN_UNDEF)
6828             deferred_exidx_sections.push_back(i);
6829           else
6830             {
6831               elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6832                                                      + text_shndx * shdr_size);
6833               this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6834             }
6835           // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6836           if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6837             gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6838                          this->section_name(i).c_str(), this->name().c_str());
6839         }
6840     }
6841
6842   // This is rare.
6843   if (!must_merge_flags_and_attributes)
6844     {
6845       gold_assert(deferred_exidx_sections.empty());
6846       this->merge_flags_and_attributes_ = false;
6847       return;
6848     }
6849
6850   // Some tools are broken and they do not set the link of EXIDX sections.
6851   // We look at the first relocation to figure out the linked sections.
6852   if (!deferred_exidx_sections.empty())
6853     {
6854       // We need to go over the section headers again to find the mapping
6855       // from sections being relocated to their relocation sections.  This is
6856       // a bit inefficient as we could do that in the loop above.  However,
6857       // we do not expect any deferred EXIDX sections normally.  So we do not
6858       // want to slow down the most common path.
6859       typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6860       Reloc_map reloc_map;
6861       ps = pshdrs + shdr_size;
6862       for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6863         {
6864           elfcpp::Shdr<32, big_endian> shdr(ps);
6865           elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6866           if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6867             {
6868               unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6869               if (info_shndx >= this->shnum())
6870                 gold_error(_("relocation section %u has invalid info %u"),
6871                            i, info_shndx);
6872               Reloc_map::value_type value(info_shndx, i);
6873               std::pair<Reloc_map::iterator, bool> result =
6874                 reloc_map.insert(value);
6875               if (!result.second)
6876                 gold_error(_("section %u has multiple relocation sections "
6877                              "%u and %u"),
6878                            info_shndx, i, reloc_map[info_shndx]);
6879             }
6880         }
6881
6882       // Read the symbol table section header.
6883       const unsigned int symtab_shndx = this->symtab_shndx();
6884       elfcpp::Shdr<32, big_endian>
6885           symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6886       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6887
6888       // Read the local symbols.
6889       const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6890       const unsigned int loccount = this->local_symbol_count();
6891       gold_assert(loccount == symtabshdr.get_sh_info());
6892       off_t locsize = loccount * sym_size;
6893       const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6894                                                   locsize, true, true);
6895
6896       // Process the deferred EXIDX sections.
6897       for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6898         {
6899           unsigned int shndx = deferred_exidx_sections[i];
6900           elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6901           unsigned int text_shndx = elfcpp::SHN_UNDEF;
6902           Reloc_map::const_iterator it = reloc_map.find(shndx);
6903           if (it != reloc_map.end())
6904             find_linked_text_section(pshdrs + it->second * shdr_size,
6905                                      psyms, &text_shndx);
6906           elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6907                                                  + text_shndx * shdr_size);
6908           this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6909         }
6910     }
6911 }
6912
6913 // Process relocations for garbage collection.  The ARM target uses .ARM.exidx
6914 // sections for unwinding.  These sections are referenced implicitly by
6915 // text sections linked in the section headers.  If we ignore these implicit
6916 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6917 // will be garbage-collected incorrectly.  Hence we override the same function
6918 // in the base class to handle these implicit references.
6919
6920 template<bool big_endian>
6921 void
6922 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6923                                              Layout* layout,
6924                                              Read_relocs_data* rd)
6925 {
6926   // First, call base class method to process relocations in this object.
6927   Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6928
6929   // If --gc-sections is not specified, there is nothing more to do.
6930   // This happens when --icf is used but --gc-sections is not.
6931   if (!parameters->options().gc_sections())
6932     return;
6933
6934   unsigned int shnum = this->shnum();
6935   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6936   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6937                                                shnum * shdr_size,
6938                                                true, true);
6939
6940   // Scan section headers for sections of type SHT_ARM_EXIDX.  Add references
6941   // to these from the linked text sections.
6942   const unsigned char* ps = pshdrs + shdr_size;
6943   for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6944     {
6945       elfcpp::Shdr<32, big_endian> shdr(ps);
6946       if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6947         {
6948           // Found an .ARM.exidx section, add it to the set of reachable
6949           // sections from its linked text section.
6950           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6951           symtab->gc()->add_reference(this, text_shndx, this, i);
6952         }
6953     }
6954 }
6955
6956 // Update output local symbol count.  Owing to EXIDX entry merging, some local
6957 // symbols  will be removed in output.  Adjust output local symbol count
6958 // accordingly.  We can only changed the static output local symbol count.  It
6959 // is too late to change the dynamic symbols.
6960
6961 template<bool big_endian>
6962 void
6963 Arm_relobj<big_endian>::update_output_local_symbol_count()
6964 {
6965   // Caller should check that this needs updating.  We want caller checking
6966   // because output_local_symbol_count_needs_update() is most likely inlined.
6967   gold_assert(this->output_local_symbol_count_needs_update_);
6968
6969   gold_assert(this->symtab_shndx() != -1U);
6970   if (this->symtab_shndx() == 0)
6971     {
6972       // This object has no symbols.  Weird but legal.
6973       return;
6974     }
6975
6976   // Read the symbol table section header.
6977   const unsigned int symtab_shndx = this->symtab_shndx();
6978   elfcpp::Shdr<32, big_endian>
6979     symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6980   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6981
6982   // Read the local symbols.
6983   const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6984   const unsigned int loccount = this->local_symbol_count();
6985   gold_assert(loccount == symtabshdr.get_sh_info());
6986   off_t locsize = loccount * sym_size;
6987   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6988                                               locsize, true, true);
6989
6990   // Loop over the local symbols.
6991
6992   typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6993      Output_sections;
6994   const Output_sections& out_sections(this->output_sections());
6995   unsigned int shnum = this->shnum();
6996   unsigned int count = 0;
6997   // Skip the first, dummy, symbol.
6998   psyms += sym_size;
6999   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
7000     {
7001       elfcpp::Sym<32, big_endian> sym(psyms);
7002
7003       Symbol_value<32>& lv((*this->local_values())[i]);
7004
7005       // This local symbol was already discarded by do_count_local_symbols.
7006       if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
7007         continue;
7008
7009       bool is_ordinary;
7010       unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
7011                                                   &is_ordinary);
7012
7013       if (shndx < shnum)
7014         {
7015           Output_section* os = out_sections[shndx];
7016
7017           // This local symbol no longer has an output section.  Discard it.
7018           if (os == NULL)
7019             {
7020               lv.set_no_output_symtab_entry();
7021               continue;
7022             }
7023
7024           // Currently we only discard parts of EXIDX input sections.
7025           // We explicitly check for a merged EXIDX input section to avoid
7026           // calling Output_section_data::output_offset unless necessary.
7027           if ((this->get_output_section_offset(shndx) == invalid_address)
7028               && (this->exidx_input_section_by_shndx(shndx) != NULL))
7029             {
7030               section_offset_type output_offset =
7031                 os->output_offset(this, shndx, lv.input_value());
7032               if (output_offset == -1)
7033                 {
7034                   // This symbol is defined in a part of an EXIDX input section
7035                   // that is discarded due to entry merging.
7036                   lv.set_no_output_symtab_entry();
7037                   continue;
7038                 }
7039             }
7040         }
7041
7042       ++count;
7043     }
7044
7045   this->set_output_local_symbol_count(count);
7046   this->output_local_symbol_count_needs_update_ = false;
7047 }
7048
7049 // Arm_dynobj methods.
7050
7051 // Read the symbol information.
7052
7053 template<bool big_endian>
7054 void
7055 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
7056 {
7057   // Call parent class to read symbol information.
7058   this->base_read_symbols(sd);
7059
7060   // Read processor-specific flags in ELF file header.
7061   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
7062                                               elfcpp::Elf_sizes<32>::ehdr_size,
7063                                               true, false);
7064   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
7065   this->processor_specific_flags_ = ehdr.get_e_flags();
7066
7067   // Read the attributes section if there is one.
7068   // We read from the end because gas seems to put it near the end of
7069   // the section headers.
7070   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
7071   const unsigned char* ps =
7072     sd->section_headers->data() + shdr_size * (this->shnum() - 1);
7073   for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
7074     {
7075       elfcpp::Shdr<32, big_endian> shdr(ps);
7076       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
7077         {
7078           section_offset_type section_offset = shdr.get_sh_offset();
7079           section_size_type section_size =
7080             convert_to_section_size_type(shdr.get_sh_size());
7081           const unsigned char* view =
7082             this->get_view(section_offset, section_size, true, false);
7083           this->attributes_section_data_ =
7084             new Attributes_section_data(view, section_size);
7085           break;
7086         }
7087     }
7088 }
7089
7090 // Stub_addend_reader methods.
7091
7092 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7093
7094 template<bool big_endian>
7095 elfcpp::Elf_types<32>::Elf_Swxword
7096 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7097     unsigned int r_type,
7098     const unsigned char* view,
7099     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7100 {
7101   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
7102
7103   switch (r_type)
7104     {
7105     case elfcpp::R_ARM_CALL:
7106     case elfcpp::R_ARM_JUMP24:
7107     case elfcpp::R_ARM_PLT32:
7108       {
7109         typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7110         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7111         Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7112         return Bits<26>::sign_extend32(val << 2);
7113       }
7114
7115     case elfcpp::R_ARM_THM_CALL:
7116     case elfcpp::R_ARM_THM_JUMP24:
7117     case elfcpp::R_ARM_THM_XPC22:
7118       {
7119         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7120         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7121         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7122         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7123         return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7124       }
7125
7126     case elfcpp::R_ARM_THM_JUMP19:
7127       {
7128         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7129         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7130         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7131         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7132         return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7133       }
7134
7135     default:
7136       gold_unreachable();
7137     }
7138 }
7139
7140 // Arm_output_data_got methods.
7141
7142 // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
7143 // The first one is initialized to be 1, which is the module index for
7144 // the main executable and the second one 0.  A reloc of the type
7145 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7146 // be applied by gold.  GSYM is a global symbol.
7147 //
7148 template<bool big_endian>
7149 void
7150 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7151     unsigned int got_type,
7152     Symbol* gsym)
7153 {
7154   if (gsym->has_got_offset(got_type))
7155     return;
7156
7157   // We are doing a static link.  Just mark it as belong to module 1,
7158   // the executable.
7159   unsigned int got_offset = this->add_constant(1);
7160   gsym->set_got_offset(got_type, got_offset);
7161   got_offset = this->add_constant(0);
7162   this->static_relocs_.push_back(Static_reloc(got_offset,
7163                                               elfcpp::R_ARM_TLS_DTPOFF32,
7164                                               gsym));
7165 }
7166
7167 // Same as the above but for a local symbol.
7168
7169 template<bool big_endian>
7170 void
7171 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7172   unsigned int got_type,
7173   Sized_relobj_file<32, big_endian>* object,
7174   unsigned int index)
7175 {
7176   if (object->local_has_got_offset(index, got_type))
7177     return;
7178
7179   // We are doing a static link.  Just mark it as belong to module 1,
7180   // the executable.
7181   unsigned int got_offset = this->add_constant(1);
7182   object->set_local_got_offset(index, got_type, got_offset);
7183   got_offset = this->add_constant(0);
7184   this->static_relocs_.push_back(Static_reloc(got_offset,
7185                                               elfcpp::R_ARM_TLS_DTPOFF32,
7186                                               object, index));
7187 }
7188
7189 template<bool big_endian>
7190 void
7191 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7192 {
7193   // Call parent to write out GOT.
7194   Output_data_got<32, big_endian>::do_write(of);
7195
7196   // We are done if there is no fix up.
7197   if (this->static_relocs_.empty())
7198     return;
7199
7200   gold_assert(parameters->doing_static_link());
7201
7202   const off_t offset = this->offset();
7203   const section_size_type oview_size =
7204     convert_to_section_size_type(this->data_size());
7205   unsigned char* const oview = of->get_output_view(offset, oview_size);
7206
7207   Output_segment* tls_segment = this->layout_->tls_segment();
7208   gold_assert(tls_segment != NULL);
7209
7210   // The thread pointer $tp points to the TCB, which is followed by the
7211   // TLS.  So we need to adjust $tp relative addressing by this amount.
7212   Arm_address aligned_tcb_size =
7213     align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7214
7215   for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7216     {
7217       Static_reloc& reloc(this->static_relocs_[i]);
7218
7219       Arm_address value;
7220       if (!reloc.symbol_is_global())
7221         {
7222           Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7223           const Symbol_value<32>* psymval =
7224             reloc.relobj()->local_symbol(reloc.index());
7225
7226           // We are doing static linking.  Issue an error and skip this
7227           // relocation if the symbol is undefined or in a discarded_section.
7228           bool is_ordinary;
7229           unsigned int shndx = psymval->input_shndx(&is_ordinary);
7230           if ((shndx == elfcpp::SHN_UNDEF)
7231               || (is_ordinary
7232                   && shndx != elfcpp::SHN_UNDEF
7233                   && !object->is_section_included(shndx)
7234                   && !this->symbol_table_->is_section_folded(object, shndx)))
7235             {
7236               gold_error(_("undefined or discarded local symbol %u from "
7237                            " object %s in GOT"),
7238                          reloc.index(), reloc.relobj()->name().c_str());
7239               continue;
7240             }
7241
7242           value = psymval->value(object, 0);
7243         }
7244       else
7245         {
7246           const Symbol* gsym = reloc.symbol();
7247           gold_assert(gsym != NULL);
7248           if (gsym->is_forwarder())
7249             gsym = this->symbol_table_->resolve_forwards(gsym);
7250
7251           // We are doing static linking.  Issue an error and skip this
7252           // relocation if the symbol is undefined or in a discarded_section
7253           // unless it is a weakly_undefined symbol.
7254           if ((gsym->is_defined_in_discarded_section()
7255                || gsym->is_undefined())
7256               && !gsym->is_weak_undefined())
7257             {
7258               gold_error(_("undefined or discarded symbol %s in GOT"),
7259                          gsym->name());
7260               continue;
7261             }
7262
7263           if (!gsym->is_weak_undefined())
7264             {
7265               const Sized_symbol<32>* sym =
7266                 static_cast<const Sized_symbol<32>*>(gsym);
7267               value = sym->value();
7268             }
7269           else
7270               value = 0;
7271         }
7272
7273       unsigned got_offset = reloc.got_offset();
7274       gold_assert(got_offset < oview_size);
7275
7276       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7277       Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7278       Valtype x;
7279       switch (reloc.r_type())
7280         {
7281         case elfcpp::R_ARM_TLS_DTPOFF32:
7282           x = value;
7283           break;
7284         case elfcpp::R_ARM_TLS_TPOFF32:
7285           x = value + aligned_tcb_size;
7286           break;
7287         default:
7288           gold_unreachable();
7289         }
7290       elfcpp::Swap<32, big_endian>::writeval(wv, x);
7291     }
7292
7293   of->write_output_view(offset, oview_size, oview);
7294 }
7295
7296 // A class to handle the PLT data.
7297 // This is an abstract base class that handles most of the linker details
7298 // but does not know the actual contents of PLT entries.  The derived
7299 // classes below fill in those details.
7300
7301 template<bool big_endian>
7302 class Output_data_plt_arm : public Output_section_data
7303 {
7304  public:
7305   // Unlike aarch64, which records symbol value in "addend" field of relocations
7306   // and could be done at the same time an IRelative reloc is created for the
7307   // symbol, arm puts the symbol value into "GOT" table, which, however, is
7308   // issued later in Output_data_plt_arm::do_write(). So we have a struct here
7309   // to keep necessary symbol information for later use in do_write. We usually
7310   // have only a very limited number of ifuncs, so the extra data required here
7311   // is also limited.
7312
7313   struct IRelative_data
7314   {
7315     IRelative_data(Sized_symbol<32>* sized_symbol)
7316       : symbol_is_global_(true)
7317     {
7318       u_.global = sized_symbol;
7319     }
7320
7321     IRelative_data(Sized_relobj_file<32, big_endian>* relobj,
7322                    unsigned int index)
7323       : symbol_is_global_(false)
7324     {
7325       u_.local.relobj = relobj;
7326       u_.local.index = index;
7327     }
7328
7329     union
7330     {
7331       Sized_symbol<32>* global;
7332
7333       struct
7334       {
7335         Sized_relobj_file<32, big_endian>* relobj;
7336         unsigned int index;
7337       } local;
7338     } u_;
7339
7340     bool symbol_is_global_;
7341   };
7342
7343   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7344     Reloc_section;
7345
7346   Output_data_plt_arm(Layout* layout, uint64_t addralign,
7347                       Arm_output_data_got<big_endian>* got,
7348                       Output_data_space* got_plt,
7349                       Output_data_space* got_irelative);
7350
7351   // Add an entry to the PLT.
7352   void
7353   add_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym);
7354
7355   // Add the relocation for a plt entry.
7356   void
7357   add_relocation(Symbol_table* symtab, Layout* layout,
7358                  Symbol* gsym, unsigned int got_offset);
7359
7360   // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
7361   unsigned int
7362   add_local_ifunc_entry(Symbol_table* symtab, Layout*,
7363                         Sized_relobj_file<32, big_endian>* relobj,
7364                         unsigned int local_sym_index);
7365
7366   // Return the .rel.plt section data.
7367   const Reloc_section*
7368   rel_plt() const
7369   { return this->rel_; }
7370
7371   // Return the PLT relocation container for IRELATIVE.
7372   Reloc_section*
7373   rel_irelative(Symbol_table*, Layout*);
7374
7375   // Return the number of PLT entries.
7376   unsigned int
7377   entry_count() const
7378   { return this->count_ + this->irelative_count_; }
7379
7380   // Return the offset of the first non-reserved PLT entry.
7381   unsigned int
7382   first_plt_entry_offset() const
7383   { return this->do_first_plt_entry_offset(); }
7384
7385   // Return the size of a PLT entry.
7386   unsigned int
7387   get_plt_entry_size() const
7388   { return this->do_get_plt_entry_size(); }
7389
7390   // Return the PLT address for globals.
7391   uint32_t
7392   address_for_global(const Symbol*) const;
7393
7394   // Return the PLT address for locals.
7395   uint32_t
7396   address_for_local(const Relobj*, unsigned int symndx) const;
7397
7398  protected:
7399   // Fill in the first PLT entry.
7400   void
7401   fill_first_plt_entry(unsigned char* pov,
7402                        Arm_address got_address,
7403                        Arm_address plt_address)
7404   { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
7405
7406   void
7407   fill_plt_entry(unsigned char* pov,
7408                  Arm_address got_address,
7409                  Arm_address plt_address,
7410                  unsigned int got_offset,
7411                  unsigned int plt_offset)
7412   { do_fill_plt_entry(pov, got_address, plt_address, got_offset, plt_offset); }
7413
7414   virtual unsigned int
7415   do_first_plt_entry_offset() const = 0;
7416
7417   virtual unsigned int
7418   do_get_plt_entry_size() const = 0;
7419
7420   virtual void
7421   do_fill_first_plt_entry(unsigned char* pov,
7422                           Arm_address got_address,
7423                           Arm_address plt_address) = 0;
7424
7425   virtual void
7426   do_fill_plt_entry(unsigned char* pov,
7427                     Arm_address got_address,
7428                     Arm_address plt_address,
7429                     unsigned int got_offset,
7430                     unsigned int plt_offset) = 0;
7431
7432   void
7433   do_adjust_output_section(Output_section* os);
7434
7435   // Write to a map file.
7436   void
7437   do_print_to_mapfile(Mapfile* mapfile) const
7438   { mapfile->print_output_data(this, _("** PLT")); }
7439
7440  private:
7441   // Set the final size.
7442   void
7443   set_final_data_size()
7444   {
7445     this->set_data_size(this->first_plt_entry_offset()
7446                         + ((this->count_ + this->irelative_count_)
7447                            * this->get_plt_entry_size()));
7448   }
7449
7450   // Write out the PLT data.
7451   void
7452   do_write(Output_file*);
7453
7454   // Record irelative symbol data.
7455   void insert_irelative_data(const IRelative_data& idata)
7456   { irelative_data_vec_.push_back(idata); }
7457
7458   // The reloc section.
7459   Reloc_section* rel_;
7460   // The IRELATIVE relocs, if necessary.  These must follow the
7461   // regular PLT relocations.
7462   Reloc_section* irelative_rel_;
7463   // The .got section.
7464   Arm_output_data_got<big_endian>* got_;
7465   // The .got.plt section.
7466   Output_data_space* got_plt_;
7467   // The part of the .got.plt section used for IRELATIVE relocs.
7468   Output_data_space* got_irelative_;
7469   // The number of PLT entries.
7470   unsigned int count_;
7471   // Number of PLT entries with R_ARM_IRELATIVE relocs.  These
7472   // follow the regular PLT entries.
7473   unsigned int irelative_count_;
7474   // Vector for irelative data.
7475   typedef std::vector<IRelative_data> IRelative_data_vec;
7476   IRelative_data_vec irelative_data_vec_;
7477 };
7478
7479 // Create the PLT section.  The ordinary .got section is an argument,
7480 // since we need to refer to the start.  We also create our own .got
7481 // section just for PLT entries.
7482
7483 template<bool big_endian>
7484 Output_data_plt_arm<big_endian>::Output_data_plt_arm(
7485     Layout* layout, uint64_t addralign,
7486     Arm_output_data_got<big_endian>* got,
7487     Output_data_space* got_plt,
7488     Output_data_space* got_irelative)
7489   : Output_section_data(addralign), irelative_rel_(NULL),
7490     got_(got), got_plt_(got_plt), got_irelative_(got_irelative),
7491     count_(0), irelative_count_(0)
7492 {
7493   this->rel_ = new Reloc_section(false);
7494   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7495                                   elfcpp::SHF_ALLOC, this->rel_,
7496                                   ORDER_DYNAMIC_PLT_RELOCS, false);
7497 }
7498
7499 template<bool big_endian>
7500 void
7501 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7502 {
7503   os->set_entsize(0);
7504 }
7505
7506 // Add an entry to the PLT.
7507
7508 template<bool big_endian>
7509 void
7510 Output_data_plt_arm<big_endian>::add_entry(Symbol_table* symtab,
7511                                            Layout* layout,
7512                                            Symbol* gsym)
7513 {
7514   gold_assert(!gsym->has_plt_offset());
7515
7516   unsigned int* entry_count;
7517   Output_section_data_build* got;
7518
7519   // We have 2 different types of plt entry here, normal and ifunc.
7520
7521   // For normal plt, the offset begins with first_plt_entry_offset(20), and the
7522   // 1st entry offset would be 20, the second 32, third 44 ... etc.
7523
7524   // For ifunc plt, the offset begins with 0. So the first offset would 0,
7525   // second 12, third 24 ... etc.
7526
7527   // IFunc plt entries *always* come after *normal* plt entries.
7528
7529   // Notice, when computing the plt address of a certain symbol, "plt_address +
7530   // plt_offset" is no longer correct. Use target->plt_address_for_global() or
7531   // target->plt_address_for_local() instead.
7532
7533   int begin_offset = 0;
7534   if (gsym->type() == elfcpp::STT_GNU_IFUNC
7535       && gsym->can_use_relative_reloc(false))
7536     {
7537       entry_count = &this->irelative_count_;
7538       got = this->got_irelative_;
7539       // For irelative plt entries, offset is relative to the end of normal plt
7540       // entries, so it starts from 0.
7541       begin_offset = 0;
7542       // Record symbol information.
7543       this->insert_irelative_data(
7544           IRelative_data(symtab->get_sized_symbol<32>(gsym)));
7545     }
7546   else
7547     {
7548       entry_count = &this->count_;
7549       got = this->got_plt_;
7550       // Note that for normal plt entries, when setting the PLT offset we skip
7551       // the initial reserved PLT entry.
7552       begin_offset = this->first_plt_entry_offset();
7553     }
7554
7555   gsym->set_plt_offset(begin_offset
7556                        + (*entry_count) * this->get_plt_entry_size());
7557
7558   ++(*entry_count);
7559
7560   section_offset_type got_offset = got->current_data_size();
7561
7562   // Every PLT entry needs a GOT entry which points back to the PLT
7563   // entry (this will be changed by the dynamic linker, normally
7564   // lazily when the function is called).
7565   got->set_current_data_size(got_offset + 4);
7566
7567   // Every PLT entry needs a reloc.
7568   this->add_relocation(symtab, layout, gsym, got_offset);
7569
7570   // Note that we don't need to save the symbol.  The contents of the
7571   // PLT are independent of which symbols are used.  The symbols only
7572   // appear in the relocations.
7573 }
7574
7575 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.  Return
7576 // the PLT offset.
7577
7578 template<bool big_endian>
7579 unsigned int
7580 Output_data_plt_arm<big_endian>::add_local_ifunc_entry(
7581     Symbol_table* symtab,
7582     Layout* layout,
7583     Sized_relobj_file<32, big_endian>* relobj,
7584     unsigned int local_sym_index)
7585 {
7586   this->insert_irelative_data(IRelative_data(relobj, local_sym_index));
7587
7588   // Notice, when computingthe plt entry address, "plt_address + plt_offset" is
7589   // no longer correct. Use target->plt_address_for_local() instead.
7590   unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
7591   ++this->irelative_count_;
7592
7593   section_offset_type got_offset = this->got_irelative_->current_data_size();
7594
7595   // Every PLT entry needs a GOT entry which points back to the PLT
7596   // entry.
7597   this->got_irelative_->set_current_data_size(got_offset + 4);
7598
7599
7600   // Every PLT entry needs a reloc.
7601   Reloc_section* rel = this->rel_irelative(symtab, layout);
7602   rel->add_symbolless_local_addend(relobj, local_sym_index,
7603                                    elfcpp::R_ARM_IRELATIVE,
7604                                    this->got_irelative_, got_offset);
7605   return plt_offset;
7606 }
7607
7608
7609 // Add the relocation for a PLT entry.
7610
7611 template<bool big_endian>
7612 void
7613 Output_data_plt_arm<big_endian>::add_relocation(
7614     Symbol_table* symtab, Layout* layout, Symbol* gsym, unsigned int got_offset)
7615 {
7616   if (gsym->type() == elfcpp::STT_GNU_IFUNC
7617       && gsym->can_use_relative_reloc(false))
7618     {
7619       Reloc_section* rel = this->rel_irelative(symtab, layout);
7620       rel->add_symbolless_global_addend(gsym, elfcpp::R_ARM_IRELATIVE,
7621                                         this->got_irelative_, got_offset);
7622     }
7623   else
7624     {
7625       gsym->set_needs_dynsym_entry();
7626       this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7627                              got_offset);
7628     }
7629 }
7630
7631
7632 // Create the irelative relocation data.
7633
7634 template<bool big_endian>
7635 typename Output_data_plt_arm<big_endian>::Reloc_section*
7636 Output_data_plt_arm<big_endian>::rel_irelative(Symbol_table* symtab,
7637                                                 Layout* layout)
7638 {
7639   if (this->irelative_rel_ == NULL)
7640     {
7641       // Since irelative relocations goes into 'rel.dyn', we delegate the
7642       // creation of irelative_rel_ to where rel_dyn section gets created.
7643       Target_arm<big_endian>* arm_target =
7644           Target_arm<big_endian>::default_target();
7645       this->irelative_rel_ = arm_target->rel_irelative_section(layout);
7646
7647       // Make sure we have a place for the TLSDESC relocations, in
7648       // case we see any later on.
7649       // this->rel_tlsdesc(layout);
7650       if (parameters->doing_static_link())
7651         {
7652           // A statically linked executable will only have a .rel.plt section to
7653           // hold R_ARM_IRELATIVE relocs for STT_GNU_IFUNC symbols.  The library
7654           // will use these symbols to locate the IRELATIVE relocs at program
7655           // startup time.
7656           symtab->define_in_output_data("__rel_iplt_start", NULL,
7657                                         Symbol_table::PREDEFINED,
7658                                         this->irelative_rel_, 0, 0,
7659                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
7660                                         elfcpp::STV_HIDDEN, 0, false, true);
7661           symtab->define_in_output_data("__rel_iplt_end", NULL,
7662                                         Symbol_table::PREDEFINED,
7663                                         this->irelative_rel_, 0, 0,
7664                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
7665                                         elfcpp::STV_HIDDEN, 0, true, true);
7666         }
7667     }
7668   return this->irelative_rel_;
7669 }
7670
7671
7672 // Return the PLT address for a global symbol.
7673
7674 template<bool big_endian>
7675 uint32_t
7676 Output_data_plt_arm<big_endian>::address_for_global(const Symbol* gsym) const
7677 {
7678   uint64_t begin_offset = 0;
7679   if (gsym->type() == elfcpp::STT_GNU_IFUNC
7680       && gsym->can_use_relative_reloc(false))
7681     {
7682       begin_offset = (this->first_plt_entry_offset() +
7683                       this->count_ * this->get_plt_entry_size());
7684     }
7685   return this->address() + begin_offset + gsym->plt_offset();
7686 }
7687
7688
7689 // Return the PLT address for a local symbol.  These are always
7690 // IRELATIVE relocs.
7691
7692 template<bool big_endian>
7693 uint32_t
7694 Output_data_plt_arm<big_endian>::address_for_local(
7695     const Relobj* object,
7696     unsigned int r_sym) const
7697 {
7698   return (this->address()
7699           + this->first_plt_entry_offset()
7700           + this->count_ * this->get_plt_entry_size()
7701           + object->local_plt_offset(r_sym));
7702 }
7703
7704
7705 template<bool big_endian>
7706 class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
7707 {
7708  public:
7709   Output_data_plt_arm_standard(Layout* layout,
7710                                Arm_output_data_got<big_endian>* got,
7711                                Output_data_space* got_plt,
7712                                Output_data_space* got_irelative)
7713     : Output_data_plt_arm<big_endian>(layout, 4, got, got_plt, got_irelative)
7714   { }
7715
7716  protected:
7717   // Return the offset of the first non-reserved PLT entry.
7718   virtual unsigned int
7719   do_first_plt_entry_offset() const
7720   { return sizeof(first_plt_entry); }
7721
7722   // Return the size of a PLT entry.
7723   virtual unsigned int
7724   do_get_plt_entry_size() const
7725   { return sizeof(plt_entry); }
7726
7727   virtual void
7728   do_fill_first_plt_entry(unsigned char* pov,
7729                           Arm_address got_address,
7730                           Arm_address plt_address);
7731
7732   virtual void
7733   do_fill_plt_entry(unsigned char* pov,
7734                     Arm_address got_address,
7735                     Arm_address plt_address,
7736                     unsigned int got_offset,
7737                     unsigned int plt_offset);
7738
7739  private:
7740   // Template for the first PLT entry.
7741   static const uint32_t first_plt_entry[5];
7742
7743   // Template for subsequent PLT entries.
7744   static const uint32_t plt_entry[3];
7745 };
7746
7747 // ARM PLTs.
7748 // FIXME:  This is not very flexible.  Right now this has only been tested
7749 // on armv5te.  If we are to support additional architecture features like
7750 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7751
7752 // The first entry in the PLT.
7753 template<bool big_endian>
7754 const uint32_t Output_data_plt_arm_standard<big_endian>::first_plt_entry[5] =
7755 {
7756   0xe52de004,   // str   lr, [sp, #-4]!
7757   0xe59fe004,   // ldr   lr, [pc, #4]
7758   0xe08fe00e,   // add   lr, pc, lr
7759   0xe5bef008,   // ldr   pc, [lr, #8]!
7760   0x00000000,   // &GOT[0] - .
7761 };
7762
7763 template<bool big_endian>
7764 void
7765 Output_data_plt_arm_standard<big_endian>::do_fill_first_plt_entry(
7766     unsigned char* pov,
7767     Arm_address got_address,
7768     Arm_address plt_address)
7769 {
7770   // Write first PLT entry.  All but the last word are constants.
7771   const size_t num_first_plt_words = (sizeof(first_plt_entry)
7772                                       / sizeof(plt_entry[0]));
7773   for (size_t i = 0; i < num_first_plt_words - 1; i++)
7774     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7775   // Last word in first PLT entry is &GOT[0] - .
7776   elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7777                                          got_address - (plt_address + 16));
7778 }
7779
7780 // Subsequent entries in the PLT.
7781
7782 template<bool big_endian>
7783 const uint32_t Output_data_plt_arm_standard<big_endian>::plt_entry[3] =
7784 {
7785   0xe28fc600,   // add   ip, pc, #0xNN00000
7786   0xe28cca00,   // add   ip, ip, #0xNN000
7787   0xe5bcf000,   // ldr   pc, [ip, #0xNNN]!
7788 };
7789
7790 template<bool big_endian>
7791 void
7792 Output_data_plt_arm_standard<big_endian>::do_fill_plt_entry(
7793     unsigned char* pov,
7794     Arm_address got_address,
7795     Arm_address plt_address,
7796     unsigned int got_offset,
7797     unsigned int plt_offset)
7798 {
7799   int32_t offset = ((got_address + got_offset)
7800                     - (plt_address + plt_offset + 8));
7801
7802   gold_assert(offset >= 0 && offset < 0x0fffffff);
7803   uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7804   elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7805   uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7806   elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7807   uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7808   elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7809 }
7810
7811 // Write out the PLT.  This uses the hand-coded instructions above,
7812 // and adjusts them as needed.  This is all specified by the arm ELF
7813 // Processor Supplement.
7814
7815 template<bool big_endian>
7816 void
7817 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7818 {
7819   const off_t offset = this->offset();
7820   const section_size_type oview_size =
7821     convert_to_section_size_type(this->data_size());
7822   unsigned char* const oview = of->get_output_view(offset, oview_size);
7823
7824   const off_t got_file_offset = this->got_plt_->offset();
7825   gold_assert(got_file_offset + this->got_plt_->data_size()
7826               == this->got_irelative_->offset());
7827   const section_size_type got_size =
7828     convert_to_section_size_type(this->got_plt_->data_size()
7829                                  + this->got_irelative_->data_size());
7830   unsigned char* const got_view = of->get_output_view(got_file_offset,
7831                                                       got_size);
7832   unsigned char* pov = oview;
7833
7834   Arm_address plt_address = this->address();
7835   Arm_address got_address = this->got_plt_->address();
7836
7837   // Write first PLT entry.
7838   this->fill_first_plt_entry(pov, got_address, plt_address);
7839   pov += this->first_plt_entry_offset();
7840
7841   unsigned char* got_pov = got_view;
7842
7843   memset(got_pov, 0, 12);
7844   got_pov += 12;
7845
7846   unsigned int plt_offset = this->first_plt_entry_offset();
7847   unsigned int got_offset = 12;
7848   const unsigned int count = this->count_ + this->irelative_count_;
7849   gold_assert(this->irelative_count_ == this->irelative_data_vec_.size());
7850   for (unsigned int i = 0;
7851        i < count;
7852        ++i,
7853          pov += this->get_plt_entry_size(),
7854          got_pov += 4,
7855          plt_offset += this->get_plt_entry_size(),
7856          got_offset += 4)
7857     {
7858       // Set and adjust the PLT entry itself.
7859       this->fill_plt_entry(pov, got_address, plt_address,
7860                            got_offset, plt_offset);
7861
7862       Arm_address value;
7863       if (i < this->count_)
7864         {
7865           // For non-irelative got entries, the value is the beginning of plt.
7866           value = plt_address;
7867         }
7868       else
7869         {
7870           // For irelative got entries, the value is the (global/local) symbol
7871           // address.
7872           const IRelative_data& idata =
7873               this->irelative_data_vec_[i - this->count_];
7874           if (idata.symbol_is_global_)
7875             {
7876               // Set the entry in the GOT for irelative symbols.  The content is
7877               // the address of the ifunc, not the address of plt start.
7878               const Sized_symbol<32>* sized_symbol = idata.u_.global;
7879               gold_assert(sized_symbol->type() == elfcpp::STT_GNU_IFUNC);
7880               value = sized_symbol->value();
7881             }
7882           else
7883             {
7884               value = idata.u_.local.relobj->local_symbol_value(
7885                   idata.u_.local.index, 0);
7886             }
7887         }
7888       elfcpp::Swap<32, big_endian>::writeval(got_pov, value);
7889     }
7890
7891   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7892   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7893
7894   of->write_output_view(offset, oview_size, oview);
7895   of->write_output_view(got_file_offset, got_size, got_view);
7896 }
7897
7898
7899 // Create a PLT entry for a global symbol.
7900
7901 template<bool big_endian>
7902 void
7903 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7904                                        Symbol* gsym)
7905 {
7906   if (gsym->has_plt_offset())
7907     return;
7908
7909   if (this->plt_ == NULL)
7910     this->make_plt_section(symtab, layout);
7911
7912   this->plt_->add_entry(symtab, layout, gsym);
7913 }
7914
7915
7916 // Create the PLT section.
7917 template<bool big_endian>
7918 void
7919 Target_arm<big_endian>::make_plt_section(
7920   Symbol_table* symtab, Layout* layout)
7921 {
7922   if (this->plt_ == NULL)
7923     {
7924       // Create the GOT section first.
7925       this->got_section(symtab, layout);
7926
7927       // GOT for irelatives is create along with got.plt.
7928       gold_assert(this->got_ != NULL
7929                   && this->got_plt_ != NULL
7930                   && this->got_irelative_ != NULL);
7931       this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_,
7932                                        this->got_irelative_);
7933
7934       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7935                                       (elfcpp::SHF_ALLOC
7936                                        | elfcpp::SHF_EXECINSTR),
7937                                       this->plt_, ORDER_PLT, false);
7938       symtab->define_in_output_data("$a", NULL,
7939                                     Symbol_table::PREDEFINED,
7940                                     this->plt_,
7941                                     0, 0, elfcpp::STT_NOTYPE,
7942                                     elfcpp::STB_LOCAL,
7943                                     elfcpp::STV_DEFAULT, 0,
7944                                     false, false);
7945     }
7946 }
7947
7948
7949 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
7950
7951 template<bool big_endian>
7952 void
7953 Target_arm<big_endian>::make_local_ifunc_plt_entry(
7954     Symbol_table* symtab, Layout* layout,
7955     Sized_relobj_file<32, big_endian>* relobj,
7956     unsigned int local_sym_index)
7957 {
7958   if (relobj->local_has_plt_offset(local_sym_index))
7959     return;
7960   if (this->plt_ == NULL)
7961     this->make_plt_section(symtab, layout);
7962   unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
7963                                                               relobj,
7964                                                               local_sym_index);
7965   relobj->set_local_plt_offset(local_sym_index, plt_offset);
7966 }
7967
7968
7969 // Return the number of entries in the PLT.
7970
7971 template<bool big_endian>
7972 unsigned int
7973 Target_arm<big_endian>::plt_entry_count() const
7974 {
7975   if (this->plt_ == NULL)
7976     return 0;
7977   return this->plt_->entry_count();
7978 }
7979
7980 // Return the offset of the first non-reserved PLT entry.
7981
7982 template<bool big_endian>
7983 unsigned int
7984 Target_arm<big_endian>::first_plt_entry_offset() const
7985 {
7986   return this->plt_->first_plt_entry_offset();
7987 }
7988
7989 // Return the size of each PLT entry.
7990
7991 template<bool big_endian>
7992 unsigned int
7993 Target_arm<big_endian>::plt_entry_size() const
7994 {
7995   return this->plt_->get_plt_entry_size();
7996 }
7997
7998 // Get the section to use for TLS_DESC relocations.
7999
8000 template<bool big_endian>
8001 typename Target_arm<big_endian>::Reloc_section*
8002 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
8003 {
8004   return this->plt_section()->rel_tls_desc(layout);
8005 }
8006
8007 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
8008
8009 template<bool big_endian>
8010 void
8011 Target_arm<big_endian>::define_tls_base_symbol(
8012     Symbol_table* symtab,
8013     Layout* layout)
8014 {
8015   if (this->tls_base_symbol_defined_)
8016     return;
8017
8018   Output_segment* tls_segment = layout->tls_segment();
8019   if (tls_segment != NULL)
8020     {
8021       bool is_exec = parameters->options().output_is_executable();
8022       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
8023                                        Symbol_table::PREDEFINED,
8024                                        tls_segment, 0, 0,
8025                                        elfcpp::STT_TLS,
8026                                        elfcpp::STB_LOCAL,
8027                                        elfcpp::STV_HIDDEN, 0,
8028                                        (is_exec
8029                                         ? Symbol::SEGMENT_END
8030                                         : Symbol::SEGMENT_START),
8031                                        true);
8032     }
8033   this->tls_base_symbol_defined_ = true;
8034 }
8035
8036 // Create a GOT entry for the TLS module index.
8037
8038 template<bool big_endian>
8039 unsigned int
8040 Target_arm<big_endian>::got_mod_index_entry(
8041     Symbol_table* symtab,
8042     Layout* layout,
8043     Sized_relobj_file<32, big_endian>* object)
8044 {
8045   if (this->got_mod_index_offset_ == -1U)
8046     {
8047       gold_assert(symtab != NULL && layout != NULL && object != NULL);
8048       Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
8049       unsigned int got_offset;
8050       if (!parameters->doing_static_link())
8051         {
8052           got_offset = got->add_constant(0);
8053           Reloc_section* rel_dyn = this->rel_dyn_section(layout);
8054           rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
8055                              got_offset);
8056         }
8057       else
8058         {
8059           // We are doing a static link.  Just mark it as belong to module 1,
8060           // the executable.
8061           got_offset = got->add_constant(1);
8062         }
8063
8064       got->add_constant(0);
8065       this->got_mod_index_offset_ = got_offset;
8066     }
8067   return this->got_mod_index_offset_;
8068 }
8069
8070 // Optimize the TLS relocation type based on what we know about the
8071 // symbol.  IS_FINAL is true if the final address of this symbol is
8072 // known at link time.
8073
8074 template<bool big_endian>
8075 tls::Tls_optimization
8076 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
8077 {
8078   // FIXME: Currently we do not do any TLS optimization.
8079   return tls::TLSOPT_NONE;
8080 }
8081
8082 // Get the Reference_flags for a particular relocation.
8083
8084 template<bool big_endian>
8085 int
8086 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
8087 {
8088   switch (r_type)
8089     {
8090     case elfcpp::R_ARM_NONE:
8091     case elfcpp::R_ARM_V4BX:
8092     case elfcpp::R_ARM_GNU_VTENTRY:
8093     case elfcpp::R_ARM_GNU_VTINHERIT:
8094       // No symbol reference.
8095       return 0;
8096
8097     case elfcpp::R_ARM_ABS32:
8098     case elfcpp::R_ARM_ABS16:
8099     case elfcpp::R_ARM_ABS12:
8100     case elfcpp::R_ARM_THM_ABS5:
8101     case elfcpp::R_ARM_ABS8:
8102     case elfcpp::R_ARM_BASE_ABS:
8103     case elfcpp::R_ARM_MOVW_ABS_NC:
8104     case elfcpp::R_ARM_MOVT_ABS:
8105     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8106     case elfcpp::R_ARM_THM_MOVT_ABS:
8107     case elfcpp::R_ARM_ABS32_NOI:
8108       return Symbol::ABSOLUTE_REF;
8109
8110     case elfcpp::R_ARM_REL32:
8111     case elfcpp::R_ARM_LDR_PC_G0:
8112     case elfcpp::R_ARM_SBREL32:
8113     case elfcpp::R_ARM_THM_PC8:
8114     case elfcpp::R_ARM_BASE_PREL:
8115     case elfcpp::R_ARM_MOVW_PREL_NC:
8116     case elfcpp::R_ARM_MOVT_PREL:
8117     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8118     case elfcpp::R_ARM_THM_MOVT_PREL:
8119     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8120     case elfcpp::R_ARM_THM_PC12:
8121     case elfcpp::R_ARM_REL32_NOI:
8122     case elfcpp::R_ARM_ALU_PC_G0_NC:
8123     case elfcpp::R_ARM_ALU_PC_G0:
8124     case elfcpp::R_ARM_ALU_PC_G1_NC:
8125     case elfcpp::R_ARM_ALU_PC_G1:
8126     case elfcpp::R_ARM_ALU_PC_G2:
8127     case elfcpp::R_ARM_LDR_PC_G1:
8128     case elfcpp::R_ARM_LDR_PC_G2:
8129     case elfcpp::R_ARM_LDRS_PC_G0:
8130     case elfcpp::R_ARM_LDRS_PC_G1:
8131     case elfcpp::R_ARM_LDRS_PC_G2:
8132     case elfcpp::R_ARM_LDC_PC_G0:
8133     case elfcpp::R_ARM_LDC_PC_G1:
8134     case elfcpp::R_ARM_LDC_PC_G2:
8135     case elfcpp::R_ARM_ALU_SB_G0_NC:
8136     case elfcpp::R_ARM_ALU_SB_G0:
8137     case elfcpp::R_ARM_ALU_SB_G1_NC:
8138     case elfcpp::R_ARM_ALU_SB_G1:
8139     case elfcpp::R_ARM_ALU_SB_G2:
8140     case elfcpp::R_ARM_LDR_SB_G0:
8141     case elfcpp::R_ARM_LDR_SB_G1:
8142     case elfcpp::R_ARM_LDR_SB_G2:
8143     case elfcpp::R_ARM_LDRS_SB_G0:
8144     case elfcpp::R_ARM_LDRS_SB_G1:
8145     case elfcpp::R_ARM_LDRS_SB_G2:
8146     case elfcpp::R_ARM_LDC_SB_G0:
8147     case elfcpp::R_ARM_LDC_SB_G1:
8148     case elfcpp::R_ARM_LDC_SB_G2:
8149     case elfcpp::R_ARM_MOVW_BREL_NC:
8150     case elfcpp::R_ARM_MOVT_BREL:
8151     case elfcpp::R_ARM_MOVW_BREL:
8152     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8153     case elfcpp::R_ARM_THM_MOVT_BREL:
8154     case elfcpp::R_ARM_THM_MOVW_BREL:
8155     case elfcpp::R_ARM_GOTOFF32:
8156     case elfcpp::R_ARM_GOTOFF12:
8157     case elfcpp::R_ARM_SBREL31:
8158       return Symbol::RELATIVE_REF;
8159
8160     case elfcpp::R_ARM_PLT32:
8161     case elfcpp::R_ARM_CALL:
8162     case elfcpp::R_ARM_JUMP24:
8163     case elfcpp::R_ARM_THM_CALL:
8164     case elfcpp::R_ARM_THM_JUMP24:
8165     case elfcpp::R_ARM_THM_JUMP19:
8166     case elfcpp::R_ARM_THM_JUMP6:
8167     case elfcpp::R_ARM_THM_JUMP11:
8168     case elfcpp::R_ARM_THM_JUMP8:
8169     // R_ARM_PREL31 is not used to relocate call/jump instructions but
8170     // in unwind tables. It may point to functions via PLTs.
8171     // So we treat it like call/jump relocations above.
8172     case elfcpp::R_ARM_PREL31:
8173       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
8174
8175     case elfcpp::R_ARM_GOT_BREL:
8176     case elfcpp::R_ARM_GOT_ABS:
8177     case elfcpp::R_ARM_GOT_PREL:
8178       // Absolute in GOT.
8179       return Symbol::ABSOLUTE_REF;
8180
8181     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8182     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8183     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8184     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8185     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8186       return Symbol::TLS_REF;
8187
8188     case elfcpp::R_ARM_TARGET1:
8189     case elfcpp::R_ARM_TARGET2:
8190     case elfcpp::R_ARM_COPY:
8191     case elfcpp::R_ARM_GLOB_DAT:
8192     case elfcpp::R_ARM_JUMP_SLOT:
8193     case elfcpp::R_ARM_RELATIVE:
8194     case elfcpp::R_ARM_PC24:
8195     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8196     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8197     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8198     default:
8199       // Not expected.  We will give an error later.
8200       return 0;
8201     }
8202 }
8203
8204 // Report an unsupported relocation against a local symbol.
8205
8206 template<bool big_endian>
8207 void
8208 Target_arm<big_endian>::Scan::unsupported_reloc_local(
8209     Sized_relobj_file<32, big_endian>* object,
8210     unsigned int r_type)
8211 {
8212   gold_error(_("%s: unsupported reloc %u against local symbol"),
8213              object->name().c_str(), r_type);
8214 }
8215
8216 // We are about to emit a dynamic relocation of type R_TYPE.  If the
8217 // dynamic linker does not support it, issue an error.  The GNU linker
8218 // only issues a non-PIC error for an allocated read-only section.
8219 // Here we know the section is allocated, but we don't know that it is
8220 // read-only.  But we check for all the relocation types which the
8221 // glibc dynamic linker supports, so it seems appropriate to issue an
8222 // error even if the section is not read-only.
8223
8224 template<bool big_endian>
8225 void
8226 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
8227                                             unsigned int r_type)
8228 {
8229   switch (r_type)
8230     {
8231     // These are the relocation types supported by glibc for ARM.
8232     case elfcpp::R_ARM_RELATIVE:
8233     case elfcpp::R_ARM_COPY:
8234     case elfcpp::R_ARM_GLOB_DAT:
8235     case elfcpp::R_ARM_JUMP_SLOT:
8236     case elfcpp::R_ARM_ABS32:
8237     case elfcpp::R_ARM_ABS32_NOI:
8238     case elfcpp::R_ARM_IRELATIVE:
8239     case elfcpp::R_ARM_PC24:
8240     // FIXME: The following 3 types are not supported by Android's dynamic
8241     // linker.
8242     case elfcpp::R_ARM_TLS_DTPMOD32:
8243     case elfcpp::R_ARM_TLS_DTPOFF32:
8244     case elfcpp::R_ARM_TLS_TPOFF32:
8245       return;
8246
8247     default:
8248       {
8249         // This prevents us from issuing more than one error per reloc
8250         // section.  But we can still wind up issuing more than one
8251         // error per object file.
8252         if (this->issued_non_pic_error_)
8253           return;
8254         const Arm_reloc_property* reloc_property =
8255           arm_reloc_property_table->get_reloc_property(r_type);
8256         gold_assert(reloc_property != NULL);
8257         object->error(_("requires unsupported dynamic reloc %s; "
8258                       "recompile with -fPIC"),
8259                       reloc_property->name().c_str());
8260         this->issued_non_pic_error_ = true;
8261         return;
8262       }
8263
8264     case elfcpp::R_ARM_NONE:
8265       gold_unreachable();
8266     }
8267 }
8268
8269
8270 // Return whether we need to make a PLT entry for a relocation of the
8271 // given type against a STT_GNU_IFUNC symbol.
8272
8273 template<bool big_endian>
8274 bool
8275 Target_arm<big_endian>::Scan::reloc_needs_plt_for_ifunc(
8276     Sized_relobj_file<32, big_endian>* object,
8277     unsigned int r_type)
8278 {
8279   int flags = Scan::get_reference_flags(r_type);
8280   if (flags & Symbol::TLS_REF)
8281     {
8282       gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
8283                  object->name().c_str(), r_type);
8284       return false;
8285     }
8286   return flags != 0;
8287 }
8288
8289
8290 // Scan a relocation for a local symbol.
8291 // FIXME: This only handles a subset of relocation types used by Android
8292 // on ARM v5te devices.
8293
8294 template<bool big_endian>
8295 inline void
8296 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
8297                                     Layout* layout,
8298                                     Target_arm* target,
8299                                     Sized_relobj_file<32, big_endian>* object,
8300                                     unsigned int data_shndx,
8301                                     Output_section* output_section,
8302                                     const elfcpp::Rel<32, big_endian>& reloc,
8303                                     unsigned int r_type,
8304                                     const elfcpp::Sym<32, big_endian>& lsym,
8305                                     bool is_discarded)
8306 {
8307   if (is_discarded)
8308     return;
8309
8310   r_type = get_real_reloc_type(r_type);
8311
8312   // A local STT_GNU_IFUNC symbol may require a PLT entry.
8313   bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
8314   if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
8315     {
8316       unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8317       target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
8318     }
8319
8320   switch (r_type)
8321     {
8322     case elfcpp::R_ARM_NONE:
8323     case elfcpp::R_ARM_V4BX:
8324     case elfcpp::R_ARM_GNU_VTENTRY:
8325     case elfcpp::R_ARM_GNU_VTINHERIT:
8326       break;
8327
8328     case elfcpp::R_ARM_ABS32:
8329     case elfcpp::R_ARM_ABS32_NOI:
8330       // If building a shared library (or a position-independent
8331       // executable), we need to create a dynamic relocation for
8332       // this location. The relocation applied at link time will
8333       // apply the link-time value, so we flag the location with
8334       // an R_ARM_RELATIVE relocation so the dynamic loader can
8335       // relocate it easily.
8336       if (parameters->options().output_is_position_independent())
8337         {
8338           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8339           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8340           // If we are to add more other reloc types than R_ARM_ABS32,
8341           // we need to add check_non_pic(object, r_type) here.
8342           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
8343                                       output_section, data_shndx,
8344                                       reloc.get_r_offset(), is_ifunc);
8345         }
8346       break;
8347
8348     case elfcpp::R_ARM_ABS16:
8349     case elfcpp::R_ARM_ABS12:
8350     case elfcpp::R_ARM_THM_ABS5:
8351     case elfcpp::R_ARM_ABS8:
8352     case elfcpp::R_ARM_BASE_ABS:
8353     case elfcpp::R_ARM_MOVW_ABS_NC:
8354     case elfcpp::R_ARM_MOVT_ABS:
8355     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8356     case elfcpp::R_ARM_THM_MOVT_ABS:
8357       // If building a shared library (or a position-independent
8358       // executable), we need to create a dynamic relocation for
8359       // this location. Because the addend needs to remain in the
8360       // data section, we need to be careful not to apply this
8361       // relocation statically.
8362       if (parameters->options().output_is_position_independent())
8363         {
8364           check_non_pic(object, r_type);
8365           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8366           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8367           if (lsym.get_st_type() != elfcpp::STT_SECTION)
8368             rel_dyn->add_local(object, r_sym, r_type, output_section,
8369                                data_shndx, reloc.get_r_offset());
8370           else
8371             {
8372               gold_assert(lsym.get_st_value() == 0);
8373               unsigned int shndx = lsym.get_st_shndx();
8374               bool is_ordinary;
8375               shndx = object->adjust_sym_shndx(r_sym, shndx,
8376                                                &is_ordinary);
8377               if (!is_ordinary)
8378                 object->error(_("section symbol %u has bad shndx %u"),
8379                               r_sym, shndx);
8380               else
8381                 rel_dyn->add_local_section(object, shndx,
8382                                            r_type, output_section,
8383                                            data_shndx, reloc.get_r_offset());
8384             }
8385         }
8386       break;
8387
8388     case elfcpp::R_ARM_REL32:
8389     case elfcpp::R_ARM_LDR_PC_G0:
8390     case elfcpp::R_ARM_SBREL32:
8391     case elfcpp::R_ARM_THM_CALL:
8392     case elfcpp::R_ARM_THM_PC8:
8393     case elfcpp::R_ARM_BASE_PREL:
8394     case elfcpp::R_ARM_PLT32:
8395     case elfcpp::R_ARM_CALL:
8396     case elfcpp::R_ARM_JUMP24:
8397     case elfcpp::R_ARM_THM_JUMP24:
8398     case elfcpp::R_ARM_SBREL31:
8399     case elfcpp::R_ARM_PREL31:
8400     case elfcpp::R_ARM_MOVW_PREL_NC:
8401     case elfcpp::R_ARM_MOVT_PREL:
8402     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8403     case elfcpp::R_ARM_THM_MOVT_PREL:
8404     case elfcpp::R_ARM_THM_JUMP19:
8405     case elfcpp::R_ARM_THM_JUMP6:
8406     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8407     case elfcpp::R_ARM_THM_PC12:
8408     case elfcpp::R_ARM_REL32_NOI:
8409     case elfcpp::R_ARM_ALU_PC_G0_NC:
8410     case elfcpp::R_ARM_ALU_PC_G0:
8411     case elfcpp::R_ARM_ALU_PC_G1_NC:
8412     case elfcpp::R_ARM_ALU_PC_G1:
8413     case elfcpp::R_ARM_ALU_PC_G2:
8414     case elfcpp::R_ARM_LDR_PC_G1:
8415     case elfcpp::R_ARM_LDR_PC_G2:
8416     case elfcpp::R_ARM_LDRS_PC_G0:
8417     case elfcpp::R_ARM_LDRS_PC_G1:
8418     case elfcpp::R_ARM_LDRS_PC_G2:
8419     case elfcpp::R_ARM_LDC_PC_G0:
8420     case elfcpp::R_ARM_LDC_PC_G1:
8421     case elfcpp::R_ARM_LDC_PC_G2:
8422     case elfcpp::R_ARM_ALU_SB_G0_NC:
8423     case elfcpp::R_ARM_ALU_SB_G0:
8424     case elfcpp::R_ARM_ALU_SB_G1_NC:
8425     case elfcpp::R_ARM_ALU_SB_G1:
8426     case elfcpp::R_ARM_ALU_SB_G2:
8427     case elfcpp::R_ARM_LDR_SB_G0:
8428     case elfcpp::R_ARM_LDR_SB_G1:
8429     case elfcpp::R_ARM_LDR_SB_G2:
8430     case elfcpp::R_ARM_LDRS_SB_G0:
8431     case elfcpp::R_ARM_LDRS_SB_G1:
8432     case elfcpp::R_ARM_LDRS_SB_G2:
8433     case elfcpp::R_ARM_LDC_SB_G0:
8434     case elfcpp::R_ARM_LDC_SB_G1:
8435     case elfcpp::R_ARM_LDC_SB_G2:
8436     case elfcpp::R_ARM_MOVW_BREL_NC:
8437     case elfcpp::R_ARM_MOVT_BREL:
8438     case elfcpp::R_ARM_MOVW_BREL:
8439     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8440     case elfcpp::R_ARM_THM_MOVT_BREL:
8441     case elfcpp::R_ARM_THM_MOVW_BREL:
8442     case elfcpp::R_ARM_THM_JUMP11:
8443     case elfcpp::R_ARM_THM_JUMP8:
8444       // We don't need to do anything for a relative addressing relocation
8445       // against a local symbol if it does not reference the GOT.
8446       break;
8447
8448     case elfcpp::R_ARM_GOTOFF32:
8449     case elfcpp::R_ARM_GOTOFF12:
8450       // We need a GOT section:
8451       target->got_section(symtab, layout);
8452       break;
8453
8454     case elfcpp::R_ARM_GOT_BREL:
8455     case elfcpp::R_ARM_GOT_PREL:
8456       {
8457         // The symbol requires a GOT entry.
8458         Arm_output_data_got<big_endian>* got =
8459           target->got_section(symtab, layout);
8460         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8461         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
8462           {
8463             // If we are generating a shared object, we need to add a
8464             // dynamic RELATIVE relocation for this symbol's GOT entry.
8465             if (parameters->options().output_is_position_independent())
8466               {
8467                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8468                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8469                 rel_dyn->add_local_relative(
8470                     object, r_sym, elfcpp::R_ARM_RELATIVE, got,
8471                     object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
8472               }
8473           }
8474       }
8475       break;
8476
8477     case elfcpp::R_ARM_TARGET1:
8478     case elfcpp::R_ARM_TARGET2:
8479       // This should have been mapped to another type already.
8480       // Fall through.
8481     case elfcpp::R_ARM_COPY:
8482     case elfcpp::R_ARM_GLOB_DAT:
8483     case elfcpp::R_ARM_JUMP_SLOT:
8484     case elfcpp::R_ARM_RELATIVE:
8485       // These are relocations which should only be seen by the
8486       // dynamic linker, and should never be seen here.
8487       gold_error(_("%s: unexpected reloc %u in object file"),
8488                  object->name().c_str(), r_type);
8489       break;
8490
8491
8492       // These are initial TLS relocs, which are expected when
8493       // linking.
8494     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8495     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8496     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8497     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8498     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8499       {
8500         bool output_is_shared = parameters->options().shared();
8501         const tls::Tls_optimization optimized_type
8502             = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
8503                                                          r_type);
8504         switch (r_type)
8505           {
8506           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8507             if (optimized_type == tls::TLSOPT_NONE)
8508               {
8509                 // Create a pair of GOT entries for the module index and
8510                 // dtv-relative offset.
8511                 Arm_output_data_got<big_endian>* got
8512                     = target->got_section(symtab, layout);
8513                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8514                 unsigned int shndx = lsym.get_st_shndx();
8515                 bool is_ordinary;
8516                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
8517                 if (!is_ordinary)
8518                   {
8519                     object->error(_("local symbol %u has bad shndx %u"),
8520                                   r_sym, shndx);
8521                     break;
8522                   }
8523
8524                 if (!parameters->doing_static_link())
8525                   got->add_local_pair_with_rel(object, r_sym, shndx,
8526                                                GOT_TYPE_TLS_PAIR,
8527                                                target->rel_dyn_section(layout),
8528                                                elfcpp::R_ARM_TLS_DTPMOD32);
8529                 else
8530                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
8531                                                       object, r_sym);
8532               }
8533             else
8534               // FIXME: TLS optimization not supported yet.
8535               gold_unreachable();
8536             break;
8537
8538           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
8539             if (optimized_type == tls::TLSOPT_NONE)
8540               {
8541                 // Create a GOT entry for the module index.
8542                 target->got_mod_index_entry(symtab, layout, object);
8543               }
8544             else
8545               // FIXME: TLS optimization not supported yet.
8546               gold_unreachable();
8547             break;
8548
8549           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
8550             break;
8551
8552           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
8553             layout->set_has_static_tls();
8554             if (optimized_type == tls::TLSOPT_NONE)
8555               {
8556                 // Create a GOT entry for the tp-relative offset.
8557                 Arm_output_data_got<big_endian>* got
8558                   = target->got_section(symtab, layout);
8559                 unsigned int r_sym =
8560                    elfcpp::elf_r_sym<32>(reloc.get_r_info());
8561                 if (!parameters->doing_static_link())
8562                     got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
8563                                             target->rel_dyn_section(layout),
8564                                             elfcpp::R_ARM_TLS_TPOFF32);
8565                 else if (!object->local_has_got_offset(r_sym,
8566                                                        GOT_TYPE_TLS_OFFSET))
8567                   {
8568                     got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
8569                     unsigned int got_offset =
8570                       object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
8571                     got->add_static_reloc(got_offset,
8572                                           elfcpp::R_ARM_TLS_TPOFF32, object,
8573                                           r_sym);
8574                   }
8575               }
8576             else
8577               // FIXME: TLS optimization not supported yet.
8578               gold_unreachable();
8579             break;
8580
8581           case elfcpp::R_ARM_TLS_LE32:          // Local-exec
8582             layout->set_has_static_tls();
8583             if (output_is_shared)
8584               {
8585                 // We need to create a dynamic relocation.
8586                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8587                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8588                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8589                 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8590                                    output_section, data_shndx,
8591                                    reloc.get_r_offset());
8592               }
8593             break;
8594
8595           default:
8596             gold_unreachable();
8597           }
8598       }
8599       break;
8600
8601     case elfcpp::R_ARM_PC24:
8602     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8603     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8604     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8605     default:
8606       unsupported_reloc_local(object, r_type);
8607       break;
8608     }
8609 }
8610
8611 // Report an unsupported relocation against a global symbol.
8612
8613 template<bool big_endian>
8614 void
8615 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8616     Sized_relobj_file<32, big_endian>* object,
8617     unsigned int r_type,
8618     Symbol* gsym)
8619 {
8620   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8621              object->name().c_str(), r_type, gsym->demangled_name().c_str());
8622 }
8623
8624 template<bool big_endian>
8625 inline bool
8626 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8627     unsigned int r_type)
8628 {
8629   switch (r_type)
8630     {
8631     case elfcpp::R_ARM_PC24:
8632     case elfcpp::R_ARM_THM_CALL:
8633     case elfcpp::R_ARM_PLT32:
8634     case elfcpp::R_ARM_CALL:
8635     case elfcpp::R_ARM_JUMP24:
8636     case elfcpp::R_ARM_THM_JUMP24:
8637     case elfcpp::R_ARM_SBREL31:
8638     case elfcpp::R_ARM_PREL31:
8639     case elfcpp::R_ARM_THM_JUMP19:
8640     case elfcpp::R_ARM_THM_JUMP6:
8641     case elfcpp::R_ARM_THM_JUMP11:
8642     case elfcpp::R_ARM_THM_JUMP8:
8643       // All the relocations above are branches except SBREL31 and PREL31.
8644       return false;
8645
8646     default:
8647       // Be conservative and assume this is a function pointer.
8648       return true;
8649     }
8650 }
8651
8652 template<bool big_endian>
8653 inline bool
8654 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8655   Symbol_table*,
8656   Layout*,
8657   Target_arm<big_endian>* target,
8658   Sized_relobj_file<32, big_endian>*,
8659   unsigned int,
8660   Output_section*,
8661   const elfcpp::Rel<32, big_endian>&,
8662   unsigned int r_type,
8663   const elfcpp::Sym<32, big_endian>&)
8664 {
8665   r_type = target->get_real_reloc_type(r_type);
8666   return possible_function_pointer_reloc(r_type);
8667 }
8668
8669 template<bool big_endian>
8670 inline bool
8671 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8672   Symbol_table*,
8673   Layout*,
8674   Target_arm<big_endian>* target,
8675   Sized_relobj_file<32, big_endian>*,
8676   unsigned int,
8677   Output_section*,
8678   const elfcpp::Rel<32, big_endian>&,
8679   unsigned int r_type,
8680   Symbol* gsym)
8681 {
8682   // GOT is not a function.
8683   if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8684     return false;
8685
8686   r_type = target->get_real_reloc_type(r_type);
8687   return possible_function_pointer_reloc(r_type);
8688 }
8689
8690 // Scan a relocation for a global symbol.
8691
8692 template<bool big_endian>
8693 inline void
8694 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8695                                      Layout* layout,
8696                                      Target_arm* target,
8697                                      Sized_relobj_file<32, big_endian>* object,
8698                                      unsigned int data_shndx,
8699                                      Output_section* output_section,
8700                                      const elfcpp::Rel<32, big_endian>& reloc,
8701                                      unsigned int r_type,
8702                                      Symbol* gsym)
8703 {
8704   // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8705   // section.  We check here to avoid creating a dynamic reloc against
8706   // _GLOBAL_OFFSET_TABLE_.
8707   if (!target->has_got_section()
8708       && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8709     target->got_section(symtab, layout);
8710
8711   // A STT_GNU_IFUNC symbol may require a PLT entry.
8712   if (gsym->type() == elfcpp::STT_GNU_IFUNC
8713       && this->reloc_needs_plt_for_ifunc(object, r_type))
8714     target->make_plt_entry(symtab, layout, gsym);
8715
8716   r_type = get_real_reloc_type(r_type);
8717   switch (r_type)
8718     {
8719     case elfcpp::R_ARM_NONE:
8720     case elfcpp::R_ARM_V4BX:
8721     case elfcpp::R_ARM_GNU_VTENTRY:
8722     case elfcpp::R_ARM_GNU_VTINHERIT:
8723       break;
8724
8725     case elfcpp::R_ARM_ABS32:
8726     case elfcpp::R_ARM_ABS16:
8727     case elfcpp::R_ARM_ABS12:
8728     case elfcpp::R_ARM_THM_ABS5:
8729     case elfcpp::R_ARM_ABS8:
8730     case elfcpp::R_ARM_BASE_ABS:
8731     case elfcpp::R_ARM_MOVW_ABS_NC:
8732     case elfcpp::R_ARM_MOVT_ABS:
8733     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8734     case elfcpp::R_ARM_THM_MOVT_ABS:
8735     case elfcpp::R_ARM_ABS32_NOI:
8736       // Absolute addressing relocations.
8737       {
8738         // Make a PLT entry if necessary.
8739         if (this->symbol_needs_plt_entry(gsym))
8740           {
8741             target->make_plt_entry(symtab, layout, gsym);
8742             // Since this is not a PC-relative relocation, we may be
8743             // taking the address of a function. In that case we need to
8744             // set the entry in the dynamic symbol table to the address of
8745             // the PLT entry.
8746             if (gsym->is_from_dynobj() && !parameters->options().shared())
8747               gsym->set_needs_dynsym_value();
8748           }
8749         // Make a dynamic relocation if necessary.
8750         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8751           {
8752             if (!parameters->options().output_is_position_independent()
8753                 && gsym->may_need_copy_reloc())
8754               {
8755                 target->copy_reloc(symtab, layout, object,
8756                                    data_shndx, output_section, gsym, reloc);
8757               }
8758             else if ((r_type == elfcpp::R_ARM_ABS32
8759                       || r_type == elfcpp::R_ARM_ABS32_NOI)
8760                      && gsym->type() == elfcpp::STT_GNU_IFUNC
8761                      && gsym->can_use_relative_reloc(false)
8762                      && !gsym->is_from_dynobj()
8763                      && !gsym->is_undefined()
8764                      && !gsym->is_preemptible())
8765               {
8766                 // Use an IRELATIVE reloc for a locally defined STT_GNU_IFUNC
8767                 // symbol. This makes a function address in a PIE executable
8768                 // match the address in a shared library that it links against.
8769                 Reloc_section* rel_irelative =
8770                     target->rel_irelative_section(layout);
8771                 unsigned int r_type = elfcpp::R_ARM_IRELATIVE;
8772                 rel_irelative->add_symbolless_global_addend(
8773                     gsym, r_type, output_section, object,
8774                     data_shndx, reloc.get_r_offset());
8775               }
8776             else if ((r_type == elfcpp::R_ARM_ABS32
8777                       || r_type == elfcpp::R_ARM_ABS32_NOI)
8778                      && gsym->can_use_relative_reloc(false))
8779               {
8780                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8781                 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8782                                              output_section, object,
8783                                              data_shndx, reloc.get_r_offset());
8784               }
8785             else
8786               {
8787                 check_non_pic(object, r_type);
8788                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8789                 rel_dyn->add_global(gsym, r_type, output_section, object,
8790                                     data_shndx, reloc.get_r_offset());
8791               }
8792           }
8793       }
8794       break;
8795
8796     case elfcpp::R_ARM_GOTOFF32:
8797     case elfcpp::R_ARM_GOTOFF12:
8798       // We need a GOT section.
8799       target->got_section(symtab, layout);
8800       break;
8801
8802     case elfcpp::R_ARM_REL32:
8803     case elfcpp::R_ARM_LDR_PC_G0:
8804     case elfcpp::R_ARM_SBREL32:
8805     case elfcpp::R_ARM_THM_PC8:
8806     case elfcpp::R_ARM_BASE_PREL:
8807     case elfcpp::R_ARM_MOVW_PREL_NC:
8808     case elfcpp::R_ARM_MOVT_PREL:
8809     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8810     case elfcpp::R_ARM_THM_MOVT_PREL:
8811     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8812     case elfcpp::R_ARM_THM_PC12:
8813     case elfcpp::R_ARM_REL32_NOI:
8814     case elfcpp::R_ARM_ALU_PC_G0_NC:
8815     case elfcpp::R_ARM_ALU_PC_G0:
8816     case elfcpp::R_ARM_ALU_PC_G1_NC:
8817     case elfcpp::R_ARM_ALU_PC_G1:
8818     case elfcpp::R_ARM_ALU_PC_G2:
8819     case elfcpp::R_ARM_LDR_PC_G1:
8820     case elfcpp::R_ARM_LDR_PC_G2:
8821     case elfcpp::R_ARM_LDRS_PC_G0:
8822     case elfcpp::R_ARM_LDRS_PC_G1:
8823     case elfcpp::R_ARM_LDRS_PC_G2:
8824     case elfcpp::R_ARM_LDC_PC_G0:
8825     case elfcpp::R_ARM_LDC_PC_G1:
8826     case elfcpp::R_ARM_LDC_PC_G2:
8827     case elfcpp::R_ARM_ALU_SB_G0_NC:
8828     case elfcpp::R_ARM_ALU_SB_G0:
8829     case elfcpp::R_ARM_ALU_SB_G1_NC:
8830     case elfcpp::R_ARM_ALU_SB_G1:
8831     case elfcpp::R_ARM_ALU_SB_G2:
8832     case elfcpp::R_ARM_LDR_SB_G0:
8833     case elfcpp::R_ARM_LDR_SB_G1:
8834     case elfcpp::R_ARM_LDR_SB_G2:
8835     case elfcpp::R_ARM_LDRS_SB_G0:
8836     case elfcpp::R_ARM_LDRS_SB_G1:
8837     case elfcpp::R_ARM_LDRS_SB_G2:
8838     case elfcpp::R_ARM_LDC_SB_G0:
8839     case elfcpp::R_ARM_LDC_SB_G1:
8840     case elfcpp::R_ARM_LDC_SB_G2:
8841     case elfcpp::R_ARM_MOVW_BREL_NC:
8842     case elfcpp::R_ARM_MOVT_BREL:
8843     case elfcpp::R_ARM_MOVW_BREL:
8844     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8845     case elfcpp::R_ARM_THM_MOVT_BREL:
8846     case elfcpp::R_ARM_THM_MOVW_BREL:
8847       // Relative addressing relocations.
8848       {
8849         // Make a dynamic relocation if necessary.
8850         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8851           {
8852             if (parameters->options().output_is_executable()
8853                 && target->may_need_copy_reloc(gsym))
8854               {
8855                 target->copy_reloc(symtab, layout, object,
8856                                    data_shndx, output_section, gsym, reloc);
8857               }
8858             else
8859               {
8860                 check_non_pic(object, r_type);
8861                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8862                 rel_dyn->add_global(gsym, r_type, output_section, object,
8863                                     data_shndx, reloc.get_r_offset());
8864               }
8865           }
8866       }
8867       break;
8868
8869     case elfcpp::R_ARM_THM_CALL:
8870     case elfcpp::R_ARM_PLT32:
8871     case elfcpp::R_ARM_CALL:
8872     case elfcpp::R_ARM_JUMP24:
8873     case elfcpp::R_ARM_THM_JUMP24:
8874     case elfcpp::R_ARM_SBREL31:
8875     case elfcpp::R_ARM_PREL31:
8876     case elfcpp::R_ARM_THM_JUMP19:
8877     case elfcpp::R_ARM_THM_JUMP6:
8878     case elfcpp::R_ARM_THM_JUMP11:
8879     case elfcpp::R_ARM_THM_JUMP8:
8880       // All the relocation above are branches except for the PREL31 ones.
8881       // A PREL31 relocation can point to a personality function in a shared
8882       // library.  In that case we want to use a PLT because we want to
8883       // call the personality routine and the dynamic linkers we care about
8884       // do not support dynamic PREL31 relocations. An REL31 relocation may
8885       // point to a function whose unwinding behaviour is being described but
8886       // we will not mistakenly generate a PLT for that because we should use
8887       // a local section symbol.
8888
8889       // If the symbol is fully resolved, this is just a relative
8890       // local reloc.  Otherwise we need a PLT entry.
8891       if (gsym->final_value_is_known())
8892         break;
8893       // If building a shared library, we can also skip the PLT entry
8894       // if the symbol is defined in the output file and is protected
8895       // or hidden.
8896       if (gsym->is_defined()
8897           && !gsym->is_from_dynobj()
8898           && !gsym->is_preemptible())
8899         break;
8900       target->make_plt_entry(symtab, layout, gsym);
8901       break;
8902
8903     case elfcpp::R_ARM_GOT_BREL:
8904     case elfcpp::R_ARM_GOT_ABS:
8905     case elfcpp::R_ARM_GOT_PREL:
8906       {
8907         // The symbol requires a GOT entry.
8908         Arm_output_data_got<big_endian>* got =
8909           target->got_section(symtab, layout);
8910         if (gsym->final_value_is_known())
8911           {
8912             // For a STT_GNU_IFUNC symbol we want the PLT address.
8913             if (gsym->type() == elfcpp::STT_GNU_IFUNC)
8914               got->add_global_plt(gsym, GOT_TYPE_STANDARD);
8915             else
8916               got->add_global(gsym, GOT_TYPE_STANDARD);
8917           }
8918         else
8919           {
8920             // If this symbol is not fully resolved, we need to add a
8921             // GOT entry with a dynamic relocation.
8922             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8923             if (gsym->is_from_dynobj()
8924                 || gsym->is_undefined()
8925                 || gsym->is_preemptible()
8926                 || (gsym->visibility() == elfcpp::STV_PROTECTED
8927                     && parameters->options().shared())
8928                 || (gsym->type() == elfcpp::STT_GNU_IFUNC
8929                     && parameters->options().output_is_position_independent()))
8930               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8931                                        rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8932             else
8933               {
8934                 // For a STT_GNU_IFUNC symbol we want to write the PLT
8935                 // offset into the GOT, so that function pointer
8936                 // comparisons work correctly.
8937                 bool is_new;
8938                 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
8939                   is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
8940                 else
8941                   {
8942                     is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
8943                     // Tell the dynamic linker to use the PLT address
8944                     // when resolving relocations.
8945                     if (gsym->is_from_dynobj()
8946                         && !parameters->options().shared())
8947                       gsym->set_needs_dynsym_value();
8948                   }
8949                 if (is_new)
8950                   rel_dyn->add_global_relative(
8951                       gsym, elfcpp::R_ARM_RELATIVE, got,
8952                       gsym->got_offset(GOT_TYPE_STANDARD));
8953               }
8954           }
8955       }
8956       break;
8957
8958     case elfcpp::R_ARM_TARGET1:
8959     case elfcpp::R_ARM_TARGET2:
8960       // These should have been mapped to other types already.
8961       // Fall through.
8962     case elfcpp::R_ARM_COPY:
8963     case elfcpp::R_ARM_GLOB_DAT:
8964     case elfcpp::R_ARM_JUMP_SLOT:
8965     case elfcpp::R_ARM_RELATIVE:
8966       // These are relocations which should only be seen by the
8967       // dynamic linker, and should never be seen here.
8968       gold_error(_("%s: unexpected reloc %u in object file"),
8969                  object->name().c_str(), r_type);
8970       break;
8971
8972       // These are initial tls relocs, which are expected when
8973       // linking.
8974     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8975     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8976     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8977     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8978     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8979       {
8980         const bool is_final = gsym->final_value_is_known();
8981         const tls::Tls_optimization optimized_type
8982             = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8983         switch (r_type)
8984           {
8985           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8986             if (optimized_type == tls::TLSOPT_NONE)
8987               {
8988                 // Create a pair of GOT entries for the module index and
8989                 // dtv-relative offset.
8990                 Arm_output_data_got<big_endian>* got
8991                     = target->got_section(symtab, layout);
8992                 if (!parameters->doing_static_link())
8993                   got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8994                                                 target->rel_dyn_section(layout),
8995                                                 elfcpp::R_ARM_TLS_DTPMOD32,
8996                                                 elfcpp::R_ARM_TLS_DTPOFF32);
8997                 else
8998                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8999               }
9000             else
9001               // FIXME: TLS optimization not supported yet.
9002               gold_unreachable();
9003             break;
9004
9005           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
9006             if (optimized_type == tls::TLSOPT_NONE)
9007               {
9008                 // Create a GOT entry for the module index.
9009                 target->got_mod_index_entry(symtab, layout, object);
9010               }
9011             else
9012               // FIXME: TLS optimization not supported yet.
9013               gold_unreachable();
9014             break;
9015
9016           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
9017             break;
9018
9019           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
9020             layout->set_has_static_tls();
9021             if (optimized_type == tls::TLSOPT_NONE)
9022               {
9023                 // Create a GOT entry for the tp-relative offset.
9024                 Arm_output_data_got<big_endian>* got
9025                   = target->got_section(symtab, layout);
9026                 if (!parameters->doing_static_link())
9027                   got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
9028                                            target->rel_dyn_section(layout),
9029                                            elfcpp::R_ARM_TLS_TPOFF32);
9030                 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
9031                   {
9032                     got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
9033                     unsigned int got_offset =
9034                        gsym->got_offset(GOT_TYPE_TLS_OFFSET);
9035                     got->add_static_reloc(got_offset,
9036                                           elfcpp::R_ARM_TLS_TPOFF32, gsym);
9037                   }
9038               }
9039             else
9040               // FIXME: TLS optimization not supported yet.
9041               gold_unreachable();
9042             break;
9043
9044           case elfcpp::R_ARM_TLS_LE32:  // Local-exec
9045             layout->set_has_static_tls();
9046             if (parameters->options().shared())
9047               {
9048                 // We need to create a dynamic relocation.
9049                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
9050                 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
9051                                     output_section, object,
9052                                     data_shndx, reloc.get_r_offset());
9053               }
9054             break;
9055
9056           default:
9057             gold_unreachable();
9058           }
9059       }
9060       break;
9061
9062     case elfcpp::R_ARM_PC24:
9063     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9064     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9065     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9066     default:
9067       unsupported_reloc_global(object, r_type, gsym);
9068       break;
9069     }
9070 }
9071
9072 // Process relocations for gc.
9073
9074 template<bool big_endian>
9075 void
9076 Target_arm<big_endian>::gc_process_relocs(
9077     Symbol_table* symtab,
9078     Layout* layout,
9079     Sized_relobj_file<32, big_endian>* object,
9080     unsigned int data_shndx,
9081     unsigned int,
9082     const unsigned char* prelocs,
9083     size_t reloc_count,
9084     Output_section* output_section,
9085     bool needs_special_offset_handling,
9086     size_t local_symbol_count,
9087     const unsigned char* plocal_symbols)
9088 {
9089   typedef Target_arm<big_endian> Arm;
9090   typedef typename Target_arm<big_endian>::Scan Scan;
9091
9092   gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
9093                           typename Target_arm::Relocatable_size_for_reloc>(
9094     symtab,
9095     layout,
9096     this,
9097     object,
9098     data_shndx,
9099     prelocs,
9100     reloc_count,
9101     output_section,
9102     needs_special_offset_handling,
9103     local_symbol_count,
9104     plocal_symbols);
9105 }
9106
9107 // Scan relocations for a section.
9108
9109 template<bool big_endian>
9110 void
9111 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
9112                                     Layout* layout,
9113                                     Sized_relobj_file<32, big_endian>* object,
9114                                     unsigned int data_shndx,
9115                                     unsigned int sh_type,
9116                                     const unsigned char* prelocs,
9117                                     size_t reloc_count,
9118                                     Output_section* output_section,
9119                                     bool needs_special_offset_handling,
9120                                     size_t local_symbol_count,
9121                                     const unsigned char* plocal_symbols)
9122 {
9123   typedef typename Target_arm<big_endian>::Scan Scan;
9124   if (sh_type == elfcpp::SHT_RELA)
9125     {
9126       gold_error(_("%s: unsupported RELA reloc section"),
9127                  object->name().c_str());
9128       return;
9129     }
9130
9131   gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
9132     symtab,
9133     layout,
9134     this,
9135     object,
9136     data_shndx,
9137     prelocs,
9138     reloc_count,
9139     output_section,
9140     needs_special_offset_handling,
9141     local_symbol_count,
9142     plocal_symbols);
9143 }
9144
9145 // Finalize the sections.
9146
9147 template<bool big_endian>
9148 void
9149 Target_arm<big_endian>::do_finalize_sections(
9150     Layout* layout,
9151     const Input_objects* input_objects,
9152     Symbol_table*)
9153 {
9154   bool merged_any_attributes = false;
9155   // Merge processor-specific flags.
9156   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
9157        p != input_objects->relobj_end();
9158        ++p)
9159     {
9160       Arm_relobj<big_endian>* arm_relobj =
9161         Arm_relobj<big_endian>::as_arm_relobj(*p);
9162       if (arm_relobj->merge_flags_and_attributes())
9163         {
9164           this->merge_processor_specific_flags(
9165               arm_relobj->name(),
9166               arm_relobj->processor_specific_flags());
9167           this->merge_object_attributes(arm_relobj->name().c_str(),
9168                                         arm_relobj->attributes_section_data());
9169           merged_any_attributes = true;
9170         }
9171     }
9172
9173   for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
9174        p != input_objects->dynobj_end();
9175        ++p)
9176     {
9177       Arm_dynobj<big_endian>* arm_dynobj =
9178         Arm_dynobj<big_endian>::as_arm_dynobj(*p);
9179       this->merge_processor_specific_flags(
9180           arm_dynobj->name(),
9181           arm_dynobj->processor_specific_flags());
9182       this->merge_object_attributes(arm_dynobj->name().c_str(),
9183                                     arm_dynobj->attributes_section_data());
9184       merged_any_attributes = true;
9185     }
9186
9187   // Create an empty uninitialized attribute section if we still don't have it
9188   // at this moment.  This happens if there is no attributes sections in all
9189   // inputs.
9190   if (this->attributes_section_data_ == NULL)
9191     this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
9192
9193   const Object_attribute* cpu_arch_attr =
9194     this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
9195   // Check if we need to use Cortex-A8 workaround.
9196   if (parameters->options().user_set_fix_cortex_a8())
9197     this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
9198   else
9199     {
9200       // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
9201       // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
9202       // profile.
9203       const Object_attribute* cpu_arch_profile_attr =
9204         this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
9205       this->fix_cortex_a8_ =
9206         (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
9207          && (cpu_arch_profile_attr->int_value() == 'A'
9208              || cpu_arch_profile_attr->int_value() == 0));
9209     }
9210
9211   // Check if we can use V4BX interworking.
9212   // The V4BX interworking stub contains BX instruction,
9213   // which is not specified for some profiles.
9214   if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
9215       && !this->may_use_v4t_interworking())
9216     gold_error(_("unable to provide V4BX reloc interworking fix up; "
9217                  "the target profile does not support BX instruction"));
9218
9219   // Fill in some more dynamic tags.
9220   const Reloc_section* rel_plt = (this->plt_ == NULL
9221                                   ? NULL
9222                                   : this->plt_->rel_plt());
9223   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
9224                                   this->rel_dyn_, true, false);
9225
9226   // Emit any relocs we saved in an attempt to avoid generating COPY
9227   // relocs.
9228   if (this->copy_relocs_.any_saved_relocs())
9229     this->copy_relocs_.emit(this->rel_dyn_section(layout));
9230
9231   // Handle the .ARM.exidx section.
9232   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
9233
9234   if (!parameters->options().relocatable())
9235     {
9236       if (exidx_section != NULL
9237           && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
9238         {
9239           // For the ARM target, we need to add a PT_ARM_EXIDX segment for
9240           // the .ARM.exidx section.
9241           if (!layout->script_options()->saw_phdrs_clause())
9242             {
9243               gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
9244                                                       0)
9245                           == NULL);
9246               Output_segment*  exidx_segment =
9247                 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
9248               exidx_segment->add_output_section_to_nonload(exidx_section,
9249                                                            elfcpp::PF_R);
9250             }
9251         }
9252     }
9253
9254   // Create an .ARM.attributes section if we have merged any attributes
9255   // from inputs.
9256   if (merged_any_attributes)
9257     {
9258       Output_attributes_section_data* attributes_section =
9259       new Output_attributes_section_data(*this->attributes_section_data_);
9260       layout->add_output_section_data(".ARM.attributes",
9261                                       elfcpp::SHT_ARM_ATTRIBUTES, 0,
9262                                       attributes_section, ORDER_INVALID,
9263                                       false);
9264     }
9265
9266   // Fix up links in section EXIDX headers.
9267   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
9268        p != layout->section_list().end();
9269        ++p)
9270     if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
9271       {
9272         Arm_output_section<big_endian>* os =
9273           Arm_output_section<big_endian>::as_arm_output_section(*p);
9274         os->set_exidx_section_link();
9275       }
9276 }
9277
9278 // Return whether a direct absolute static relocation needs to be applied.
9279 // In cases where Scan::local() or Scan::global() has created
9280 // a dynamic relocation other than R_ARM_RELATIVE, the addend
9281 // of the relocation is carried in the data, and we must not
9282 // apply the static relocation.
9283
9284 template<bool big_endian>
9285 inline bool
9286 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
9287     const Sized_symbol<32>* gsym,
9288     unsigned int r_type,
9289     bool is_32bit,
9290     Output_section* output_section)
9291 {
9292   // If the output section is not allocated, then we didn't call
9293   // scan_relocs, we didn't create a dynamic reloc, and we must apply
9294   // the reloc here.
9295   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
9296       return true;
9297
9298   int ref_flags = Scan::get_reference_flags(r_type);
9299
9300   // For local symbols, we will have created a non-RELATIVE dynamic
9301   // relocation only if (a) the output is position independent,
9302   // (b) the relocation is absolute (not pc- or segment-relative), and
9303   // (c) the relocation is not 32 bits wide.
9304   if (gsym == NULL)
9305     return !(parameters->options().output_is_position_independent()
9306              && (ref_flags & Symbol::ABSOLUTE_REF)
9307              && !is_32bit);
9308
9309   // For global symbols, we use the same helper routines used in the
9310   // scan pass.  If we did not create a dynamic relocation, or if we
9311   // created a RELATIVE dynamic relocation, we should apply the static
9312   // relocation.
9313   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
9314   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
9315                  && gsym->can_use_relative_reloc(ref_flags
9316                                                  & Symbol::FUNCTION_CALL);
9317   return !has_dyn || is_rel;
9318 }
9319
9320 // Perform a relocation.
9321
9322 template<bool big_endian>
9323 inline bool
9324 Target_arm<big_endian>::Relocate::relocate(
9325     const Relocate_info<32, big_endian>* relinfo,
9326     Target_arm* target,
9327     Output_section* output_section,
9328     size_t relnum,
9329     const elfcpp::Rel<32, big_endian>& rel,
9330     unsigned int r_type,
9331     const Sized_symbol<32>* gsym,
9332     const Symbol_value<32>* psymval,
9333     unsigned char* view,
9334     Arm_address address,
9335     section_size_type view_size)
9336 {
9337   if (view == NULL)
9338     return true;
9339
9340   typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
9341
9342   r_type = get_real_reloc_type(r_type);
9343   const Arm_reloc_property* reloc_property =
9344     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9345   if (reloc_property == NULL)
9346     {
9347       std::string reloc_name =
9348         arm_reloc_property_table->reloc_name_in_error_message(r_type);
9349       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9350                              _("cannot relocate %s in object file"),
9351                              reloc_name.c_str());
9352       return true;
9353     }
9354
9355   const Arm_relobj<big_endian>* object =
9356     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9357
9358   // If the final branch target of a relocation is THUMB instruction, this
9359   // is 1.  Otherwise it is 0.
9360   Arm_address thumb_bit = 0;
9361   Symbol_value<32> symval;
9362   bool is_weakly_undefined_without_plt = false;
9363   bool have_got_offset = false;
9364   unsigned int got_offset = 0;
9365
9366   // If the relocation uses the GOT entry of a symbol instead of the symbol
9367   // itself, we don't care about whether the symbol is defined or what kind
9368   // of symbol it is.
9369   if (reloc_property->uses_got_entry())
9370     {
9371       // Get the GOT offset.
9372       // The GOT pointer points to the end of the GOT section.
9373       // We need to subtract the size of the GOT section to get
9374       // the actual offset to use in the relocation.
9375       // TODO: We should move GOT offset computing code in TLS relocations
9376       // to here.
9377       switch (r_type)
9378         {
9379         case elfcpp::R_ARM_GOT_BREL:
9380         case elfcpp::R_ARM_GOT_PREL:
9381           if (gsym != NULL)
9382             {
9383               gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
9384               got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
9385                             - target->got_size());
9386             }
9387           else
9388             {
9389               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9390               gold_assert(object->local_has_got_offset(r_sym,
9391                                                        GOT_TYPE_STANDARD));
9392               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
9393                             - target->got_size());
9394             }
9395           have_got_offset = true;
9396           break;
9397
9398         default:
9399           break;
9400         }
9401     }
9402   else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
9403     {
9404       if (gsym != NULL)
9405         {
9406           // This is a global symbol.  Determine if we use PLT and if the
9407           // final target is THUMB.
9408           if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
9409             {
9410               // This uses a PLT, change the symbol value.
9411               symval.set_output_value(target->plt_address_for_global(gsym));
9412               psymval = &symval;
9413             }
9414           else if (gsym->is_weak_undefined())
9415             {
9416               // This is a weakly undefined symbol and we do not use PLT
9417               // for this relocation.  A branch targeting this symbol will
9418               // be converted into an NOP.
9419               is_weakly_undefined_without_plt = true;
9420             }
9421           else if (gsym->is_undefined() && reloc_property->uses_symbol())
9422             {
9423               // This relocation uses the symbol value but the symbol is
9424               // undefined.  Exit early and have the caller reporting an
9425               // error.
9426               return true;
9427             }
9428           else
9429             {
9430               // Set thumb bit if symbol:
9431               // -Has type STT_ARM_TFUNC or
9432               // -Has type STT_FUNC, is defined and with LSB in value set.
9433               thumb_bit =
9434                 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
9435                  || (gsym->type() == elfcpp::STT_FUNC
9436                      && !gsym->is_undefined()
9437                      && ((psymval->value(object, 0) & 1) != 0)))
9438                 ? 1
9439                 : 0);
9440             }
9441         }
9442       else
9443         {
9444           // This is a local symbol.  Determine if the final target is THUMB.
9445           // We saved this information when all the local symbols were read.
9446           elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
9447           unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9448           thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9449
9450           if (psymval->is_ifunc_symbol() && object->local_has_plt_offset(r_sym))
9451             {
9452               symval.set_output_value(
9453                   target->plt_address_for_local(object, r_sym));
9454               psymval = &symval;
9455             }
9456         }
9457     }
9458   else
9459     {
9460       // This is a fake relocation synthesized for a stub.  It does not have
9461       // a real symbol.  We just look at the LSB of the symbol value to
9462       // determine if the target is THUMB or not.
9463       thumb_bit = ((psymval->value(object, 0) & 1) != 0);
9464     }
9465
9466   // Strip LSB if this points to a THUMB target.
9467   if (thumb_bit != 0
9468       && reloc_property->uses_thumb_bit()
9469       && ((psymval->value(object, 0) & 1) != 0))
9470     {
9471       Arm_address stripped_value =
9472         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9473       symval.set_output_value(stripped_value);
9474       psymval = &symval;
9475     }
9476
9477   // To look up relocation stubs, we need to pass the symbol table index of
9478   // a local symbol.
9479   unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9480
9481   // Get the addressing origin of the output segment defining the
9482   // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
9483   Arm_address sym_origin = 0;
9484   if (reloc_property->uses_symbol_base())
9485     {
9486       if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
9487         // R_ARM_BASE_ABS with the NULL symbol will give the
9488         // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
9489         // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
9490         sym_origin = target->got_plt_section()->address();
9491       else if (gsym == NULL)
9492         sym_origin = 0;
9493       else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
9494         sym_origin = gsym->output_segment()->vaddr();
9495       else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
9496         sym_origin = gsym->output_data()->address();
9497
9498       // TODO: Assumes the segment base to be zero for the global symbols
9499       // till the proper support for the segment-base-relative addressing
9500       // will be implemented.  This is consistent with GNU ld.
9501     }
9502
9503   // For relative addressing relocation, find out the relative address base.
9504   Arm_address relative_address_base = 0;
9505   switch(reloc_property->relative_address_base())
9506     {
9507     case Arm_reloc_property::RAB_NONE:
9508     // Relocations with relative address bases RAB_TLS and RAB_tp are
9509     // handled by relocate_tls.  So we do not need to do anything here.
9510     case Arm_reloc_property::RAB_TLS:
9511     case Arm_reloc_property::RAB_tp:
9512       break;
9513     case Arm_reloc_property::RAB_B_S:
9514       relative_address_base = sym_origin;
9515       break;
9516     case Arm_reloc_property::RAB_GOT_ORG:
9517       relative_address_base = target->got_plt_section()->address();
9518       break;
9519     case Arm_reloc_property::RAB_P:
9520       relative_address_base = address;
9521       break;
9522     case Arm_reloc_property::RAB_Pa:
9523       relative_address_base = address & 0xfffffffcU;
9524       break;
9525     default:
9526       gold_unreachable();
9527     }
9528
9529   typename Arm_relocate_functions::Status reloc_status =
9530         Arm_relocate_functions::STATUS_OKAY;
9531   bool check_overflow = reloc_property->checks_overflow();
9532   switch (r_type)
9533     {
9534     case elfcpp::R_ARM_NONE:
9535       break;
9536
9537     case elfcpp::R_ARM_ABS8:
9538       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9539         reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
9540       break;
9541
9542     case elfcpp::R_ARM_ABS12:
9543       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9544         reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
9545       break;
9546
9547     case elfcpp::R_ARM_ABS16:
9548       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9549         reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
9550       break;
9551
9552     case elfcpp::R_ARM_ABS32:
9553       if (should_apply_static_reloc(gsym, r_type, true, output_section))
9554         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9555                                                      thumb_bit);
9556       break;
9557
9558     case elfcpp::R_ARM_ABS32_NOI:
9559       if (should_apply_static_reloc(gsym, r_type, true, output_section))
9560         // No thumb bit for this relocation: (S + A)
9561         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9562                                                      0);
9563       break;
9564
9565     case elfcpp::R_ARM_MOVW_ABS_NC:
9566       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9567         reloc_status = Arm_relocate_functions::movw(view, object, psymval,
9568                                                     0, thumb_bit,
9569                                                     check_overflow);
9570       break;
9571
9572     case elfcpp::R_ARM_MOVT_ABS:
9573       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9574         reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
9575       break;
9576
9577     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9578       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9579         reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
9580                                                         0, thumb_bit, false);
9581       break;
9582
9583     case elfcpp::R_ARM_THM_MOVT_ABS:
9584       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9585         reloc_status = Arm_relocate_functions::thm_movt(view, object,
9586                                                         psymval, 0);
9587       break;
9588
9589     case elfcpp::R_ARM_MOVW_PREL_NC:
9590     case elfcpp::R_ARM_MOVW_BREL_NC:
9591     case elfcpp::R_ARM_MOVW_BREL:
9592       reloc_status =
9593         Arm_relocate_functions::movw(view, object, psymval,
9594                                      relative_address_base, thumb_bit,
9595                                      check_overflow);
9596       break;
9597
9598     case elfcpp::R_ARM_MOVT_PREL:
9599     case elfcpp::R_ARM_MOVT_BREL:
9600       reloc_status =
9601         Arm_relocate_functions::movt(view, object, psymval,
9602                                      relative_address_base);
9603       break;
9604
9605     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9606     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9607     case elfcpp::R_ARM_THM_MOVW_BREL:
9608       reloc_status =
9609         Arm_relocate_functions::thm_movw(view, object, psymval,
9610                                          relative_address_base,
9611                                          thumb_bit, check_overflow);
9612       break;
9613
9614     case elfcpp::R_ARM_THM_MOVT_PREL:
9615     case elfcpp::R_ARM_THM_MOVT_BREL:
9616       reloc_status =
9617         Arm_relocate_functions::thm_movt(view, object, psymval,
9618                                          relative_address_base);
9619       break;
9620
9621     case elfcpp::R_ARM_REL32:
9622       reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9623                                                    address, thumb_bit);
9624       break;
9625
9626     case elfcpp::R_ARM_THM_ABS5:
9627       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9628         reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
9629       break;
9630
9631     // Thumb long branches.
9632     case elfcpp::R_ARM_THM_CALL:
9633     case elfcpp::R_ARM_THM_XPC22:
9634     case elfcpp::R_ARM_THM_JUMP24:
9635       reloc_status =
9636         Arm_relocate_functions::thumb_branch_common(
9637             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9638             thumb_bit, is_weakly_undefined_without_plt);
9639       break;
9640
9641     case elfcpp::R_ARM_GOTOFF32:
9642       {
9643         Arm_address got_origin;
9644         got_origin = target->got_plt_section()->address();
9645         reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9646                                                      got_origin, thumb_bit);
9647       }
9648       break;
9649
9650     case elfcpp::R_ARM_BASE_PREL:
9651       gold_assert(gsym != NULL);
9652       reloc_status =
9653           Arm_relocate_functions::base_prel(view, sym_origin, address);
9654       break;
9655
9656     case elfcpp::R_ARM_BASE_ABS:
9657       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9658         reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
9659       break;
9660
9661     case elfcpp::R_ARM_GOT_BREL:
9662       gold_assert(have_got_offset);
9663       reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
9664       break;
9665
9666     case elfcpp::R_ARM_GOT_PREL:
9667       gold_assert(have_got_offset);
9668       // Get the address origin for GOT PLT, which is allocated right
9669       // after the GOT section, to calculate an absolute address of
9670       // the symbol GOT entry (got_origin + got_offset).
9671       Arm_address got_origin;
9672       got_origin = target->got_plt_section()->address();
9673       reloc_status = Arm_relocate_functions::got_prel(view,
9674                                                       got_origin + got_offset,
9675                                                       address);
9676       break;
9677
9678     case elfcpp::R_ARM_PLT32:
9679     case elfcpp::R_ARM_CALL:
9680     case elfcpp::R_ARM_JUMP24:
9681     case elfcpp::R_ARM_XPC25:
9682       gold_assert(gsym == NULL
9683                   || gsym->has_plt_offset()
9684                   || gsym->final_value_is_known()
9685                   || (gsym->is_defined()
9686                       && !gsym->is_from_dynobj()
9687                       && !gsym->is_preemptible()));
9688       reloc_status =
9689         Arm_relocate_functions::arm_branch_common(
9690             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9691             thumb_bit, is_weakly_undefined_without_plt);
9692       break;
9693
9694     case elfcpp::R_ARM_THM_JUMP19:
9695       reloc_status =
9696         Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9697                                            thumb_bit);
9698       break;
9699
9700     case elfcpp::R_ARM_THM_JUMP6:
9701       reloc_status =
9702         Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9703       break;
9704
9705     case elfcpp::R_ARM_THM_JUMP8:
9706       reloc_status =
9707         Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9708       break;
9709
9710     case elfcpp::R_ARM_THM_JUMP11:
9711       reloc_status =
9712         Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9713       break;
9714
9715     case elfcpp::R_ARM_PREL31:
9716       reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9717                                                     address, thumb_bit);
9718       break;
9719
9720     case elfcpp::R_ARM_V4BX:
9721       if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9722         {
9723           const bool is_v4bx_interworking =
9724               (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9725           reloc_status =
9726             Arm_relocate_functions::v4bx(relinfo, view, object, address,
9727                                          is_v4bx_interworking);
9728         }
9729       break;
9730
9731     case elfcpp::R_ARM_THM_PC8:
9732       reloc_status =
9733         Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9734       break;
9735
9736     case elfcpp::R_ARM_THM_PC12:
9737       reloc_status =
9738         Arm_relocate_functions::thm_pc12(view, object, psymval, address);
9739       break;
9740
9741     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9742       reloc_status =
9743         Arm_relocate_functions::thm_alu11(view, object, psymval, address,
9744                                           thumb_bit);
9745       break;
9746
9747     case elfcpp::R_ARM_ALU_PC_G0_NC:
9748     case elfcpp::R_ARM_ALU_PC_G0:
9749     case elfcpp::R_ARM_ALU_PC_G1_NC:
9750     case elfcpp::R_ARM_ALU_PC_G1:
9751     case elfcpp::R_ARM_ALU_PC_G2:
9752     case elfcpp::R_ARM_ALU_SB_G0_NC:
9753     case elfcpp::R_ARM_ALU_SB_G0:
9754     case elfcpp::R_ARM_ALU_SB_G1_NC:
9755     case elfcpp::R_ARM_ALU_SB_G1:
9756     case elfcpp::R_ARM_ALU_SB_G2:
9757       reloc_status =
9758         Arm_relocate_functions::arm_grp_alu(view, object, psymval,
9759                                             reloc_property->group_index(),
9760                                             relative_address_base,
9761                                             thumb_bit, check_overflow);
9762       break;
9763
9764     case elfcpp::R_ARM_LDR_PC_G0:
9765     case elfcpp::R_ARM_LDR_PC_G1:
9766     case elfcpp::R_ARM_LDR_PC_G2:
9767     case elfcpp::R_ARM_LDR_SB_G0:
9768     case elfcpp::R_ARM_LDR_SB_G1:
9769     case elfcpp::R_ARM_LDR_SB_G2:
9770       reloc_status =
9771           Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9772                                               reloc_property->group_index(),
9773                                               relative_address_base);
9774       break;
9775
9776     case elfcpp::R_ARM_LDRS_PC_G0:
9777     case elfcpp::R_ARM_LDRS_PC_G1:
9778     case elfcpp::R_ARM_LDRS_PC_G2:
9779     case elfcpp::R_ARM_LDRS_SB_G0:
9780     case elfcpp::R_ARM_LDRS_SB_G1:
9781     case elfcpp::R_ARM_LDRS_SB_G2:
9782       reloc_status =
9783           Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9784                                                reloc_property->group_index(),
9785                                                relative_address_base);
9786       break;
9787
9788     case elfcpp::R_ARM_LDC_PC_G0:
9789     case elfcpp::R_ARM_LDC_PC_G1:
9790     case elfcpp::R_ARM_LDC_PC_G2:
9791     case elfcpp::R_ARM_LDC_SB_G0:
9792     case elfcpp::R_ARM_LDC_SB_G1:
9793     case elfcpp::R_ARM_LDC_SB_G2:
9794       reloc_status =
9795           Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9796                                               reloc_property->group_index(),
9797                                               relative_address_base);
9798       break;
9799
9800       // These are initial tls relocs, which are expected when
9801       // linking.
9802     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9803     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9804     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9805     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9806     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9807       reloc_status =
9808         this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9809                            view, address, view_size);
9810       break;
9811
9812     // The known and unknown unsupported and/or deprecated relocations.
9813     case elfcpp::R_ARM_PC24:
9814     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9815     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9816     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9817     default:
9818       // Just silently leave the method. We should get an appropriate error
9819       // message in the scan methods.
9820       break;
9821     }
9822
9823   // Report any errors.
9824   switch (reloc_status)
9825     {
9826     case Arm_relocate_functions::STATUS_OKAY:
9827       break;
9828     case Arm_relocate_functions::STATUS_OVERFLOW:
9829       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9830                              _("relocation overflow in %s"),
9831                              reloc_property->name().c_str());
9832       break;
9833     case Arm_relocate_functions::STATUS_BAD_RELOC:
9834       gold_error_at_location(
9835         relinfo,
9836         relnum,
9837         rel.get_r_offset(),
9838         _("unexpected opcode while processing relocation %s"),
9839         reloc_property->name().c_str());
9840       break;
9841     default:
9842       gold_unreachable();
9843     }
9844
9845   return true;
9846 }
9847
9848 // Perform a TLS relocation.
9849
9850 template<bool big_endian>
9851 inline typename Arm_relocate_functions<big_endian>::Status
9852 Target_arm<big_endian>::Relocate::relocate_tls(
9853     const Relocate_info<32, big_endian>* relinfo,
9854     Target_arm<big_endian>* target,
9855     size_t relnum,
9856     const elfcpp::Rel<32, big_endian>& rel,
9857     unsigned int r_type,
9858     const Sized_symbol<32>* gsym,
9859     const Symbol_value<32>* psymval,
9860     unsigned char* view,
9861     elfcpp::Elf_types<32>::Elf_Addr address,
9862     section_size_type /*view_size*/ )
9863 {
9864   typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9865   typedef Relocate_functions<32, big_endian> RelocFuncs;
9866   Output_segment* tls_segment = relinfo->layout->tls_segment();
9867
9868   const Sized_relobj_file<32, big_endian>* object = relinfo->object;
9869
9870   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9871
9872   const bool is_final = (gsym == NULL
9873                          ? !parameters->options().shared()
9874                          : gsym->final_value_is_known());
9875   const tls::Tls_optimization optimized_type
9876       = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9877   switch (r_type)
9878     {
9879     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9880         {
9881           unsigned int got_type = GOT_TYPE_TLS_PAIR;
9882           unsigned int got_offset;
9883           if (gsym != NULL)
9884             {
9885               gold_assert(gsym->has_got_offset(got_type));
9886               got_offset = gsym->got_offset(got_type) - target->got_size();
9887             }
9888           else
9889             {
9890               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9891               gold_assert(object->local_has_got_offset(r_sym, got_type));
9892               got_offset = (object->local_got_offset(r_sym, got_type)
9893                             - target->got_size());
9894             }
9895           if (optimized_type == tls::TLSOPT_NONE)
9896             {
9897               Arm_address got_entry =
9898                 target->got_plt_section()->address() + got_offset;
9899
9900               // Relocate the field with the PC relative offset of the pair of
9901               // GOT entries.
9902               RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9903               return ArmRelocFuncs::STATUS_OKAY;
9904             }
9905         }
9906       break;
9907
9908     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9909       if (optimized_type == tls::TLSOPT_NONE)
9910         {
9911           // Relocate the field with the offset of the GOT entry for
9912           // the module index.
9913           unsigned int got_offset;
9914           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9915                         - target->got_size());
9916           Arm_address got_entry =
9917             target->got_plt_section()->address() + got_offset;
9918
9919           // Relocate the field with the PC relative offset of the pair of
9920           // GOT entries.
9921           RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9922           return ArmRelocFuncs::STATUS_OKAY;
9923         }
9924       break;
9925
9926     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9927       RelocFuncs::rel32_unaligned(view, value);
9928       return ArmRelocFuncs::STATUS_OKAY;
9929
9930     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9931       if (optimized_type == tls::TLSOPT_NONE)
9932         {
9933           // Relocate the field with the offset of the GOT entry for
9934           // the tp-relative offset of the symbol.
9935           unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9936           unsigned int got_offset;
9937           if (gsym != NULL)
9938             {
9939               gold_assert(gsym->has_got_offset(got_type));
9940               got_offset = gsym->got_offset(got_type);
9941             }
9942           else
9943             {
9944               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9945               gold_assert(object->local_has_got_offset(r_sym, got_type));
9946               got_offset = object->local_got_offset(r_sym, got_type);
9947             }
9948
9949           // All GOT offsets are relative to the end of the GOT.
9950           got_offset -= target->got_size();
9951
9952           Arm_address got_entry =
9953             target->got_plt_section()->address() + got_offset;
9954
9955           // Relocate the field with the PC relative offset of the GOT entry.
9956           RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9957           return ArmRelocFuncs::STATUS_OKAY;
9958         }
9959       break;
9960
9961     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9962       // If we're creating a shared library, a dynamic relocation will
9963       // have been created for this location, so do not apply it now.
9964       if (!parameters->options().shared())
9965         {
9966           gold_assert(tls_segment != NULL);
9967
9968           // $tp points to the TCB, which is followed by the TLS, so we
9969           // need to add TCB size to the offset.
9970           Arm_address aligned_tcb_size =
9971             align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9972           RelocFuncs::rel32_unaligned(view, value + aligned_tcb_size);
9973
9974         }
9975       return ArmRelocFuncs::STATUS_OKAY;
9976
9977     default:
9978       gold_unreachable();
9979     }
9980
9981   gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9982                          _("unsupported reloc %u"),
9983                          r_type);
9984   return ArmRelocFuncs::STATUS_BAD_RELOC;
9985 }
9986
9987 // Relocate section data.
9988
9989 template<bool big_endian>
9990 void
9991 Target_arm<big_endian>::relocate_section(
9992     const Relocate_info<32, big_endian>* relinfo,
9993     unsigned int sh_type,
9994     const unsigned char* prelocs,
9995     size_t reloc_count,
9996     Output_section* output_section,
9997     bool needs_special_offset_handling,
9998     unsigned char* view,
9999     Arm_address address,
10000     section_size_type view_size,
10001     const Reloc_symbol_changes* reloc_symbol_changes)
10002 {
10003   typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
10004   gold_assert(sh_type == elfcpp::SHT_REL);
10005
10006   // See if we are relocating a relaxed input section.  If so, the view
10007   // covers the whole output section and we need to adjust accordingly.
10008   if (needs_special_offset_handling)
10009     {
10010       const Output_relaxed_input_section* poris =
10011         output_section->find_relaxed_input_section(relinfo->object,
10012                                                    relinfo->data_shndx);
10013       if (poris != NULL)
10014         {
10015           Arm_address section_address = poris->address();
10016           section_size_type section_size = poris->data_size();
10017
10018           gold_assert((section_address >= address)
10019                       && ((section_address + section_size)
10020                           <= (address + view_size)));
10021
10022           off_t offset = section_address - address;
10023           view += offset;
10024           address += offset;
10025           view_size = section_size;
10026         }
10027     }
10028
10029   gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
10030                          Arm_relocate, gold::Default_comdat_behavior>(
10031     relinfo,
10032     this,
10033     prelocs,
10034     reloc_count,
10035     output_section,
10036     needs_special_offset_handling,
10037     view,
10038     address,
10039     view_size,
10040     reloc_symbol_changes);
10041 }
10042
10043 // Return the size of a relocation while scanning during a relocatable
10044 // link.
10045
10046 template<bool big_endian>
10047 unsigned int
10048 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
10049     unsigned int r_type,
10050     Relobj* object)
10051 {
10052   r_type = get_real_reloc_type(r_type);
10053   const Arm_reloc_property* arp =
10054       arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10055   if (arp != NULL)
10056     return arp->size();
10057   else
10058     {
10059       std::string reloc_name =
10060         arm_reloc_property_table->reloc_name_in_error_message(r_type);
10061       gold_error(_("%s: unexpected %s in object file"),
10062                  object->name().c_str(), reloc_name.c_str());
10063       return 0;
10064     }
10065 }
10066
10067 // Scan the relocs during a relocatable link.
10068
10069 template<bool big_endian>
10070 void
10071 Target_arm<big_endian>::scan_relocatable_relocs(
10072     Symbol_table* symtab,
10073     Layout* layout,
10074     Sized_relobj_file<32, big_endian>* object,
10075     unsigned int data_shndx,
10076     unsigned int sh_type,
10077     const unsigned char* prelocs,
10078     size_t reloc_count,
10079     Output_section* output_section,
10080     bool needs_special_offset_handling,
10081     size_t local_symbol_count,
10082     const unsigned char* plocal_symbols,
10083     Relocatable_relocs* rr)
10084 {
10085   gold_assert(sh_type == elfcpp::SHT_REL);
10086
10087   typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
10088     Relocatable_size_for_reloc> Scan_relocatable_relocs;
10089
10090   gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
10091       Scan_relocatable_relocs>(
10092     symtab,
10093     layout,
10094     object,
10095     data_shndx,
10096     prelocs,
10097     reloc_count,
10098     output_section,
10099     needs_special_offset_handling,
10100     local_symbol_count,
10101     plocal_symbols,
10102     rr);
10103 }
10104
10105 // Emit relocations for a section.
10106
10107 template<bool big_endian>
10108 void
10109 Target_arm<big_endian>::relocate_relocs(
10110     const Relocate_info<32, big_endian>* relinfo,
10111     unsigned int sh_type,
10112     const unsigned char* prelocs,
10113     size_t reloc_count,
10114     Output_section* output_section,
10115     typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
10116     const Relocatable_relocs* rr,
10117     unsigned char* view,
10118     Arm_address view_address,
10119     section_size_type view_size,
10120     unsigned char* reloc_view,
10121     section_size_type reloc_view_size)
10122 {
10123   gold_assert(sh_type == elfcpp::SHT_REL);
10124
10125   gold::relocate_relocs<32, big_endian, elfcpp::SHT_REL>(
10126     relinfo,
10127     prelocs,
10128     reloc_count,
10129     output_section,
10130     offset_in_output_section,
10131     rr,
10132     view,
10133     view_address,
10134     view_size,
10135     reloc_view,
10136     reloc_view_size);
10137 }
10138
10139 // Perform target-specific processing in a relocatable link.  This is
10140 // only used if we use the relocation strategy RELOC_SPECIAL.
10141
10142 template<bool big_endian>
10143 void
10144 Target_arm<big_endian>::relocate_special_relocatable(
10145     const Relocate_info<32, big_endian>* relinfo,
10146     unsigned int sh_type,
10147     const unsigned char* preloc_in,
10148     size_t relnum,
10149     Output_section* output_section,
10150     typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
10151     unsigned char* view,
10152     elfcpp::Elf_types<32>::Elf_Addr view_address,
10153     section_size_type,
10154     unsigned char* preloc_out)
10155 {
10156   // We can only handle REL type relocation sections.
10157   gold_assert(sh_type == elfcpp::SHT_REL);
10158
10159   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
10160   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
10161     Reltype_write;
10162   const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
10163
10164   const Arm_relobj<big_endian>* object =
10165     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10166   const unsigned int local_count = object->local_symbol_count();
10167
10168   Reltype reloc(preloc_in);
10169   Reltype_write reloc_write(preloc_out);
10170
10171   elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
10172   const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
10173   const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
10174
10175   const Arm_reloc_property* arp =
10176     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10177   gold_assert(arp != NULL);
10178
10179   // Get the new symbol index.
10180   // We only use RELOC_SPECIAL strategy in local relocations.
10181   gold_assert(r_sym < local_count);
10182
10183   // We are adjusting a section symbol.  We need to find
10184   // the symbol table index of the section symbol for
10185   // the output section corresponding to input section
10186   // in which this symbol is defined.
10187   bool is_ordinary;
10188   unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
10189   gold_assert(is_ordinary);
10190   Output_section* os = object->output_section(shndx);
10191   gold_assert(os != NULL);
10192   gold_assert(os->needs_symtab_index());
10193   unsigned int new_symndx = os->symtab_index();
10194
10195   // Get the new offset--the location in the output section where
10196   // this relocation should be applied.
10197
10198   Arm_address offset = reloc.get_r_offset();
10199   Arm_address new_offset;
10200   if (offset_in_output_section != invalid_address)
10201     new_offset = offset + offset_in_output_section;
10202   else
10203     {
10204       section_offset_type sot_offset =
10205           convert_types<section_offset_type, Arm_address>(offset);
10206       section_offset_type new_sot_offset =
10207           output_section->output_offset(object, relinfo->data_shndx,
10208                                         sot_offset);
10209       gold_assert(new_sot_offset != -1);
10210       new_offset = new_sot_offset;
10211     }
10212
10213   // In an object file, r_offset is an offset within the section.
10214   // In an executable or dynamic object, generated by
10215   // --emit-relocs, r_offset is an absolute address.
10216   if (!parameters->options().relocatable())
10217     {
10218       new_offset += view_address;
10219       if (offset_in_output_section != invalid_address)
10220         new_offset -= offset_in_output_section;
10221     }
10222
10223   reloc_write.put_r_offset(new_offset);
10224   reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
10225
10226   // Handle the reloc addend.
10227   // The relocation uses a section symbol in the input file.
10228   // We are adjusting it to use a section symbol in the output
10229   // file.  The input section symbol refers to some address in
10230   // the input section.  We need the relocation in the output
10231   // file to refer to that same address.  This adjustment to
10232   // the addend is the same calculation we use for a simple
10233   // absolute relocation for the input section symbol.
10234
10235   const Symbol_value<32>* psymval = object->local_symbol(r_sym);
10236
10237   // Handle THUMB bit.
10238   Symbol_value<32> symval;
10239   Arm_address thumb_bit =
10240      object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
10241   if (thumb_bit != 0
10242       && arp->uses_thumb_bit()
10243       && ((psymval->value(object, 0) & 1) != 0))
10244     {
10245       Arm_address stripped_value =
10246         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
10247       symval.set_output_value(stripped_value);
10248       psymval = &symval;
10249     }
10250
10251   unsigned char* paddend = view + offset;
10252   typename Arm_relocate_functions<big_endian>::Status reloc_status =
10253         Arm_relocate_functions<big_endian>::STATUS_OKAY;
10254   switch (r_type)
10255     {
10256     case elfcpp::R_ARM_ABS8:
10257       reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
10258                                                               psymval);
10259       break;
10260
10261     case elfcpp::R_ARM_ABS12:
10262       reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
10263                                                                psymval);
10264       break;
10265
10266     case elfcpp::R_ARM_ABS16:
10267       reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
10268                                                                psymval);
10269       break;
10270
10271     case elfcpp::R_ARM_THM_ABS5:
10272       reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
10273                                                                   object,
10274                                                                   psymval);
10275       break;
10276
10277     case elfcpp::R_ARM_MOVW_ABS_NC:
10278     case elfcpp::R_ARM_MOVW_PREL_NC:
10279     case elfcpp::R_ARM_MOVW_BREL_NC:
10280     case elfcpp::R_ARM_MOVW_BREL:
10281       reloc_status = Arm_relocate_functions<big_endian>::movw(
10282           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
10283       break;
10284
10285     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
10286     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
10287     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
10288     case elfcpp::R_ARM_THM_MOVW_BREL:
10289       reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
10290           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
10291       break;
10292
10293     case elfcpp::R_ARM_THM_CALL:
10294     case elfcpp::R_ARM_THM_XPC22:
10295     case elfcpp::R_ARM_THM_JUMP24:
10296       reloc_status =
10297         Arm_relocate_functions<big_endian>::thumb_branch_common(
10298             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
10299             false);
10300       break;
10301
10302     case elfcpp::R_ARM_PLT32:
10303     case elfcpp::R_ARM_CALL:
10304     case elfcpp::R_ARM_JUMP24:
10305     case elfcpp::R_ARM_XPC25:
10306       reloc_status =
10307         Arm_relocate_functions<big_endian>::arm_branch_common(
10308             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
10309             false);
10310       break;
10311
10312     case elfcpp::R_ARM_THM_JUMP19:
10313       reloc_status =
10314         Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
10315                                                        psymval, 0, thumb_bit);
10316       break;
10317
10318     case elfcpp::R_ARM_THM_JUMP6:
10319       reloc_status =
10320         Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
10321                                                       0);
10322       break;
10323
10324     case elfcpp::R_ARM_THM_JUMP8:
10325       reloc_status =
10326         Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
10327                                                       0);
10328       break;
10329
10330     case elfcpp::R_ARM_THM_JUMP11:
10331       reloc_status =
10332         Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
10333                                                        0);
10334       break;
10335
10336     case elfcpp::R_ARM_PREL31:
10337       reloc_status =
10338         Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
10339                                                    thumb_bit);
10340       break;
10341
10342     case elfcpp::R_ARM_THM_PC8:
10343       reloc_status =
10344         Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
10345                                                     0);
10346       break;
10347
10348     case elfcpp::R_ARM_THM_PC12:
10349       reloc_status =
10350         Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
10351                                                      0);
10352       break;
10353
10354     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
10355       reloc_status =
10356         Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
10357                                                       0, thumb_bit);
10358       break;
10359
10360     // These relocation truncate relocation results so we cannot handle them
10361     // in a relocatable link.
10362     case elfcpp::R_ARM_MOVT_ABS:
10363     case elfcpp::R_ARM_THM_MOVT_ABS:
10364     case elfcpp::R_ARM_MOVT_PREL:
10365     case elfcpp::R_ARM_MOVT_BREL:
10366     case elfcpp::R_ARM_THM_MOVT_PREL:
10367     case elfcpp::R_ARM_THM_MOVT_BREL:
10368     case elfcpp::R_ARM_ALU_PC_G0_NC:
10369     case elfcpp::R_ARM_ALU_PC_G0:
10370     case elfcpp::R_ARM_ALU_PC_G1_NC:
10371     case elfcpp::R_ARM_ALU_PC_G1:
10372     case elfcpp::R_ARM_ALU_PC_G2:
10373     case elfcpp::R_ARM_ALU_SB_G0_NC:
10374     case elfcpp::R_ARM_ALU_SB_G0:
10375     case elfcpp::R_ARM_ALU_SB_G1_NC:
10376     case elfcpp::R_ARM_ALU_SB_G1:
10377     case elfcpp::R_ARM_ALU_SB_G2:
10378     case elfcpp::R_ARM_LDR_PC_G0:
10379     case elfcpp::R_ARM_LDR_PC_G1:
10380     case elfcpp::R_ARM_LDR_PC_G2:
10381     case elfcpp::R_ARM_LDR_SB_G0:
10382     case elfcpp::R_ARM_LDR_SB_G1:
10383     case elfcpp::R_ARM_LDR_SB_G2:
10384     case elfcpp::R_ARM_LDRS_PC_G0:
10385     case elfcpp::R_ARM_LDRS_PC_G1:
10386     case elfcpp::R_ARM_LDRS_PC_G2:
10387     case elfcpp::R_ARM_LDRS_SB_G0:
10388     case elfcpp::R_ARM_LDRS_SB_G1:
10389     case elfcpp::R_ARM_LDRS_SB_G2:
10390     case elfcpp::R_ARM_LDC_PC_G0:
10391     case elfcpp::R_ARM_LDC_PC_G1:
10392     case elfcpp::R_ARM_LDC_PC_G2:
10393     case elfcpp::R_ARM_LDC_SB_G0:
10394     case elfcpp::R_ARM_LDC_SB_G1:
10395     case elfcpp::R_ARM_LDC_SB_G2:
10396       gold_error(_("cannot handle %s in a relocatable link"),
10397                  arp->name().c_str());
10398       break;
10399
10400     default:
10401       gold_unreachable();
10402     }
10403
10404   // Report any errors.
10405   switch (reloc_status)
10406     {
10407     case Arm_relocate_functions<big_endian>::STATUS_OKAY:
10408       break;
10409     case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
10410       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
10411                              _("relocation overflow in %s"),
10412                              arp->name().c_str());
10413       break;
10414     case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
10415       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
10416         _("unexpected opcode while processing relocation %s"),
10417         arp->name().c_str());
10418       break;
10419     default:
10420       gold_unreachable();
10421     }
10422 }
10423
10424 // Return the value to use for a dynamic symbol which requires special
10425 // treatment.  This is how we support equality comparisons of function
10426 // pointers across shared library boundaries, as described in the
10427 // processor specific ABI supplement.
10428
10429 template<bool big_endian>
10430 uint64_t
10431 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
10432 {
10433   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
10434   return this->plt_address_for_global(gsym);
10435 }
10436
10437 // Map platform-specific relocs to real relocs
10438 //
10439 template<bool big_endian>
10440 unsigned int
10441 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
10442 {
10443   switch (r_type)
10444     {
10445     case elfcpp::R_ARM_TARGET1:
10446       // This is either R_ARM_ABS32 or R_ARM_REL32;
10447       return elfcpp::R_ARM_ABS32;
10448
10449     case elfcpp::R_ARM_TARGET2:
10450       // This can be any reloc type but usually is R_ARM_GOT_PREL
10451       return elfcpp::R_ARM_GOT_PREL;
10452
10453     default:
10454       return r_type;
10455     }
10456 }
10457
10458 // Whether if two EABI versions V1 and V2 are compatible.
10459
10460 template<bool big_endian>
10461 bool
10462 Target_arm<big_endian>::are_eabi_versions_compatible(
10463     elfcpp::Elf_Word v1,
10464     elfcpp::Elf_Word v2)
10465 {
10466   // v4 and v5 are the same spec before and after it was released,
10467   // so allow mixing them.
10468   if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
10469       || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
10470       || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
10471     return true;
10472
10473   return v1 == v2;
10474 }
10475
10476 // Combine FLAGS from an input object called NAME and the processor-specific
10477 // flags in the ELF header of the output.  Much of this is adapted from the
10478 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
10479 // in bfd/elf32-arm.c.
10480
10481 template<bool big_endian>
10482 void
10483 Target_arm<big_endian>::merge_processor_specific_flags(
10484     const std::string& name,
10485     elfcpp::Elf_Word flags)
10486 {
10487   if (this->are_processor_specific_flags_set())
10488     {
10489       elfcpp::Elf_Word out_flags = this->processor_specific_flags();
10490
10491       // Nothing to merge if flags equal to those in output.
10492       if (flags == out_flags)
10493         return;
10494
10495       // Complain about various flag mismatches.
10496       elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
10497       elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
10498       if (!this->are_eabi_versions_compatible(version1, version2)
10499           && parameters->options().warn_mismatch())
10500         gold_error(_("Source object %s has EABI version %d but output has "
10501                      "EABI version %d."),
10502                    name.c_str(),
10503                    (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
10504                    (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
10505     }
10506   else
10507     {
10508       // If the input is the default architecture and had the default
10509       // flags then do not bother setting the flags for the output
10510       // architecture, instead allow future merges to do this.  If no
10511       // future merges ever set these flags then they will retain their
10512       // uninitialised values, which surprise surprise, correspond
10513       // to the default values.
10514       if (flags == 0)
10515         return;
10516
10517       // This is the first time, just copy the flags.
10518       // We only copy the EABI version for now.
10519       this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
10520     }
10521 }
10522
10523 // Adjust ELF file header.
10524 template<bool big_endian>
10525 void
10526 Target_arm<big_endian>::do_adjust_elf_header(
10527     unsigned char* view,
10528     int len)
10529 {
10530   gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
10531
10532   elfcpp::Ehdr<32, big_endian> ehdr(view);
10533   elfcpp::Elf_Word flags = this->processor_specific_flags();
10534   unsigned char e_ident[elfcpp::EI_NIDENT];
10535   memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
10536
10537   if (elfcpp::arm_eabi_version(flags)
10538       == elfcpp::EF_ARM_EABI_UNKNOWN)
10539     e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
10540   else
10541     e_ident[elfcpp::EI_OSABI] = 0;
10542   e_ident[elfcpp::EI_ABIVERSION] = 0;
10543
10544   // FIXME: Do EF_ARM_BE8 adjustment.
10545
10546   // If we're working in EABI_VER5, set the hard/soft float ABI flags
10547   // as appropriate.
10548   if (elfcpp::arm_eabi_version(flags) == elfcpp::EF_ARM_EABI_VER5)
10549   {
10550     elfcpp::Elf_Half type = ehdr.get_e_type();
10551     if (type == elfcpp::ET_EXEC || type == elfcpp::ET_DYN)
10552       {
10553         Object_attribute* attr = this->get_aeabi_object_attribute(elfcpp::Tag_ABI_VFP_args);
10554         if (attr->int_value() == elfcpp::AEABI_VFP_args_vfp)
10555           flags |= elfcpp::EF_ARM_ABI_FLOAT_HARD;
10556         else
10557           flags |= elfcpp::EF_ARM_ABI_FLOAT_SOFT;
10558         this->set_processor_specific_flags(flags);
10559       }
10560   }
10561   elfcpp::Ehdr_write<32, big_endian> oehdr(view);
10562   oehdr.put_e_ident(e_ident);
10563   oehdr.put_e_flags(this->processor_specific_flags());
10564 }
10565
10566 // do_make_elf_object to override the same function in the base class.
10567 // We need to use a target-specific sub-class of
10568 // Sized_relobj_file<32, big_endian> to store ARM specific information.
10569 // Hence we need to have our own ELF object creation.
10570
10571 template<bool big_endian>
10572 Object*
10573 Target_arm<big_endian>::do_make_elf_object(
10574     const std::string& name,
10575     Input_file* input_file,
10576     off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
10577 {
10578   int et = ehdr.get_e_type();
10579   // ET_EXEC files are valid input for --just-symbols/-R,
10580   // and we treat them as relocatable objects.
10581   if (et == elfcpp::ET_REL
10582       || (et == elfcpp::ET_EXEC && input_file->just_symbols()))
10583     {
10584       Arm_relobj<big_endian>* obj =
10585         new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
10586       obj->setup();
10587       return obj;
10588     }
10589   else if (et == elfcpp::ET_DYN)
10590     {
10591       Sized_dynobj<32, big_endian>* obj =
10592         new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
10593       obj->setup();
10594       return obj;
10595     }
10596   else
10597     {
10598       gold_error(_("%s: unsupported ELF file type %d"),
10599                  name.c_str(), et);
10600       return NULL;
10601     }
10602 }
10603
10604 // Read the architecture from the Tag_also_compatible_with attribute, if any.
10605 // Returns -1 if no architecture could be read.
10606 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
10607
10608 template<bool big_endian>
10609 int
10610 Target_arm<big_endian>::get_secondary_compatible_arch(
10611     const Attributes_section_data* pasd)
10612 {
10613   const Object_attribute* known_attributes =
10614     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10615
10616   // Note: the tag and its argument below are uleb128 values, though
10617   // currently-defined values fit in one byte for each.
10618   const std::string& sv =
10619     known_attributes[elfcpp::Tag_also_compatible_with].string_value();
10620   if (sv.size() == 2
10621       && sv.data()[0] == elfcpp::Tag_CPU_arch
10622       && (sv.data()[1] & 128) != 128)
10623    return sv.data()[1];
10624
10625   // This tag is "safely ignorable", so don't complain if it looks funny.
10626   return -1;
10627 }
10628
10629 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10630 // The tag is removed if ARCH is -1.
10631 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10632
10633 template<bool big_endian>
10634 void
10635 Target_arm<big_endian>::set_secondary_compatible_arch(
10636     Attributes_section_data* pasd,
10637     int arch)
10638 {
10639   Object_attribute* known_attributes =
10640     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10641
10642   if (arch == -1)
10643     {
10644       known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10645       return;
10646     }
10647
10648   // Note: the tag and its argument below are uleb128 values, though
10649   // currently-defined values fit in one byte for each.
10650   char sv[3];
10651   sv[0] = elfcpp::Tag_CPU_arch;
10652   gold_assert(arch != 0);
10653   sv[1] = arch;
10654   sv[2] = '\0';
10655
10656   known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10657 }
10658
10659 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10660 // into account.
10661 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10662
10663 template<bool big_endian>
10664 int
10665 Target_arm<big_endian>::tag_cpu_arch_combine(
10666     const char* name,
10667     int oldtag,
10668     int* secondary_compat_out,
10669     int newtag,
10670     int secondary_compat)
10671 {
10672 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10673   static const int v6t2[] =
10674     {
10675       T(V6T2),   // PRE_V4.
10676       T(V6T2),   // V4.
10677       T(V6T2),   // V4T.
10678       T(V6T2),   // V5T.
10679       T(V6T2),   // V5TE.
10680       T(V6T2),   // V5TEJ.
10681       T(V6T2),   // V6.
10682       T(V7),     // V6KZ.
10683       T(V6T2)    // V6T2.
10684     };
10685   static const int v6k[] =
10686     {
10687       T(V6K),    // PRE_V4.
10688       T(V6K),    // V4.
10689       T(V6K),    // V4T.
10690       T(V6K),    // V5T.
10691       T(V6K),    // V5TE.
10692       T(V6K),    // V5TEJ.
10693       T(V6K),    // V6.
10694       T(V6KZ),   // V6KZ.
10695       T(V7),     // V6T2.
10696       T(V6K)     // V6K.
10697     };
10698   static const int v7[] =
10699     {
10700       T(V7),     // PRE_V4.
10701       T(V7),     // V4.
10702       T(V7),     // V4T.
10703       T(V7),     // V5T.
10704       T(V7),     // V5TE.
10705       T(V7),     // V5TEJ.
10706       T(V7),     // V6.
10707       T(V7),     // V6KZ.
10708       T(V7),     // V6T2.
10709       T(V7),     // V6K.
10710       T(V7)      // V7.
10711     };
10712   static const int v6_m[] =
10713     {
10714       -1,        // PRE_V4.
10715       -1,        // V4.
10716       T(V6K),    // V4T.
10717       T(V6K),    // V5T.
10718       T(V6K),    // V5TE.
10719       T(V6K),    // V5TEJ.
10720       T(V6K),    // V6.
10721       T(V6KZ),   // V6KZ.
10722       T(V7),     // V6T2.
10723       T(V6K),    // V6K.
10724       T(V7),     // V7.
10725       T(V6_M)    // V6_M.
10726     };
10727   static const int v6s_m[] =
10728     {
10729       -1,        // PRE_V4.
10730       -1,        // V4.
10731       T(V6K),    // V4T.
10732       T(V6K),    // V5T.
10733       T(V6K),    // V5TE.
10734       T(V6K),    // V5TEJ.
10735       T(V6K),    // V6.
10736       T(V6KZ),   // V6KZ.
10737       T(V7),     // V6T2.
10738       T(V6K),    // V6K.
10739       T(V7),     // V7.
10740       T(V6S_M),  // V6_M.
10741       T(V6S_M)   // V6S_M.
10742     };
10743   static const int v7e_m[] =
10744     {
10745       -1,       // PRE_V4.
10746       -1,       // V4.
10747       T(V7E_M), // V4T.
10748       T(V7E_M), // V5T.
10749       T(V7E_M), // V5TE.
10750       T(V7E_M), // V5TEJ.
10751       T(V7E_M), // V6.
10752       T(V7E_M), // V6KZ.
10753       T(V7E_M), // V6T2.
10754       T(V7E_M), // V6K.
10755       T(V7E_M), // V7.
10756       T(V7E_M), // V6_M.
10757       T(V7E_M), // V6S_M.
10758       T(V7E_M)  // V7E_M.
10759     };
10760   static const int v8[] =
10761     {
10762       T(V8),   // PRE_V4.
10763       T(V8),   // V4.
10764       T(V8),   // V4T.
10765       T(V8),   // V5T.
10766       T(V8),   // V5TE.
10767       T(V8),   // V5TEJ.
10768       T(V8),   // V6.
10769       T(V8),   // V6KZ.
10770       T(V8),   // V6T2.
10771       T(V8),   // V6K.
10772       T(V8),   // V7.
10773       T(V8),   // V6_M.
10774       T(V8),   // V6S_M.
10775       T(V8),   // V7E_M.
10776       T(V8)    // V8.
10777     };
10778   static const int v4t_plus_v6_m[] =
10779     {
10780       -1,               // PRE_V4.
10781       -1,               // V4.
10782       T(V4T),           // V4T.
10783       T(V5T),           // V5T.
10784       T(V5TE),          // V5TE.
10785       T(V5TEJ),         // V5TEJ.
10786       T(V6),            // V6.
10787       T(V6KZ),          // V6KZ.
10788       T(V6T2),          // V6T2.
10789       T(V6K),           // V6K.
10790       T(V7),            // V7.
10791       T(V6_M),          // V6_M.
10792       T(V6S_M),         // V6S_M.
10793       T(V7E_M),         // V7E_M.
10794       T(V8),            // V8.
10795       T(V4T_PLUS_V6_M)  // V4T plus V6_M.
10796     };
10797   static const int* comb[] =
10798     {
10799       v6t2,
10800       v6k,
10801       v7,
10802       v6_m,
10803       v6s_m,
10804       v7e_m,
10805       v8,
10806       // Pseudo-architecture.
10807       v4t_plus_v6_m
10808     };
10809
10810   // Check we've not got a higher architecture than we know about.
10811
10812   if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
10813     {
10814       gold_error(_("%s: unknown CPU architecture"), name);
10815       return -1;
10816     }
10817
10818   // Override old tag if we have a Tag_also_compatible_with on the output.
10819
10820   if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10821       || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10822     oldtag = T(V4T_PLUS_V6_M);
10823
10824   // And override the new tag if we have a Tag_also_compatible_with on the
10825   // input.
10826
10827   if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10828       || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10829     newtag = T(V4T_PLUS_V6_M);
10830
10831   // Architectures before V6KZ add features monotonically.
10832   int tagh = std::max(oldtag, newtag);
10833   if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10834     return tagh;
10835
10836   int tagl = std::min(oldtag, newtag);
10837   int result = comb[tagh - T(V6T2)][tagl];
10838
10839   // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10840   // as the canonical version.
10841   if (result == T(V4T_PLUS_V6_M))
10842     {
10843       result = T(V4T);
10844       *secondary_compat_out = T(V6_M);
10845     }
10846   else
10847     *secondary_compat_out = -1;
10848
10849   if (result == -1)
10850     {
10851       gold_error(_("%s: conflicting CPU architectures %d/%d"),
10852                  name, oldtag, newtag);
10853       return -1;
10854     }
10855
10856   return result;
10857 #undef T
10858 }
10859
10860 // Helper to print AEABI enum tag value.
10861
10862 template<bool big_endian>
10863 std::string
10864 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10865 {
10866   static const char* aeabi_enum_names[] =
10867     { "", "variable-size", "32-bit", "" };
10868   const size_t aeabi_enum_names_size =
10869     sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10870
10871   if (value < aeabi_enum_names_size)
10872     return std::string(aeabi_enum_names[value]);
10873   else
10874     {
10875       char buffer[100];
10876       sprintf(buffer, "<unknown value %u>", value);
10877       return std::string(buffer);
10878     }
10879 }
10880
10881 // Return the string value to store in TAG_CPU_name.
10882
10883 template<bool big_endian>
10884 std::string
10885 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10886 {
10887   static const char* name_table[] = {
10888     // These aren't real CPU names, but we can't guess
10889     // that from the architecture version alone.
10890    "Pre v4",
10891    "ARM v4",
10892    "ARM v4T",
10893    "ARM v5T",
10894    "ARM v5TE",
10895    "ARM v5TEJ",
10896    "ARM v6",
10897    "ARM v6KZ",
10898    "ARM v6T2",
10899    "ARM v6K",
10900    "ARM v7",
10901    "ARM v6-M",
10902    "ARM v6S-M",
10903    "ARM v7E-M",
10904    "ARM v8"
10905  };
10906  const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10907
10908   if (value < name_table_size)
10909     return std::string(name_table[value]);
10910   else
10911     {
10912       char buffer[100];
10913       sprintf(buffer, "<unknown CPU value %u>", value);
10914       return std::string(buffer);
10915     }
10916 }
10917
10918 // Query attributes object to see if integer divide instructions may be
10919 // present in an object.
10920
10921 template<bool big_endian>
10922 bool
10923 Target_arm<big_endian>::attributes_accept_div(int arch, int profile,
10924     const Object_attribute* div_attr)
10925 {
10926   switch (div_attr->int_value())
10927     {
10928     case 0:
10929       // Integer divide allowed if instruction contained in
10930       // archetecture.
10931       if (arch == elfcpp::TAG_CPU_ARCH_V7 && (profile == 'R' || profile == 'M'))
10932         return true;
10933       else if (arch >= elfcpp::TAG_CPU_ARCH_V7E_M)
10934         return true;
10935       else
10936         return false;
10937
10938     case 1:
10939       // Integer divide explicitly prohibited.
10940       return false;
10941
10942     default:
10943       // Unrecognised case - treat as allowing divide everywhere.
10944     case 2:
10945       // Integer divide allowed in ARM state.
10946       return true;
10947     }
10948 }
10949
10950 // Query attributes object to see if integer divide instructions are
10951 // forbidden to be in the object.  This is not the inverse of
10952 // attributes_accept_div.
10953
10954 template<bool big_endian>
10955 bool
10956 Target_arm<big_endian>::attributes_forbid_div(const Object_attribute* div_attr)
10957 {
10958   return div_attr->int_value() == 1;
10959 }
10960
10961 // Merge object attributes from input file called NAME with those of the
10962 // output.  The input object attributes are in the object pointed by PASD.
10963
10964 template<bool big_endian>
10965 void
10966 Target_arm<big_endian>::merge_object_attributes(
10967     const char* name,
10968     const Attributes_section_data* pasd)
10969 {
10970   // Return if there is no attributes section data.
10971   if (pasd == NULL)
10972     return;
10973
10974   // If output has no object attributes, just copy.
10975   const int vendor = Object_attribute::OBJ_ATTR_PROC;
10976   if (this->attributes_section_data_ == NULL)
10977     {
10978       this->attributes_section_data_ = new Attributes_section_data(*pasd);
10979       Object_attribute* out_attr =
10980         this->attributes_section_data_->known_attributes(vendor);
10981
10982       // We do not output objects with Tag_MPextension_use_legacy - we move
10983       //  the attribute's value to Tag_MPextension_use.  */
10984       if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10985         {
10986           if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10987               && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10988                 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10989             {
10990               gold_error(_("%s has both the current and legacy "
10991                            "Tag_MPextension_use attributes"),
10992                          name);
10993             }
10994
10995           out_attr[elfcpp::Tag_MPextension_use] =
10996             out_attr[elfcpp::Tag_MPextension_use_legacy];
10997           out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10998           out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10999         }
11000
11001       return;
11002     }
11003
11004   const Object_attribute* in_attr = pasd->known_attributes(vendor);
11005   Object_attribute* out_attr =
11006     this->attributes_section_data_->known_attributes(vendor);
11007
11008   // This needs to happen before Tag_ABI_FP_number_model is merged.  */
11009   if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
11010       != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
11011     {
11012       // Ignore mismatches if the object doesn't use floating point.  */
11013       if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
11014           == elfcpp::AEABI_FP_number_model_none
11015           || (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
11016               != elfcpp::AEABI_FP_number_model_none
11017               && out_attr[elfcpp::Tag_ABI_VFP_args].int_value()
11018                  == elfcpp::AEABI_VFP_args_compatible))
11019         out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
11020             in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
11021       else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
11022                != elfcpp::AEABI_FP_number_model_none
11023                && in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
11024                   != elfcpp::AEABI_VFP_args_compatible
11025                && parameters->options().warn_mismatch())
11026         gold_error(_("%s uses VFP register arguments, output does not"),
11027                    name);
11028     }
11029
11030   for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
11031     {
11032       // Merge this attribute with existing attributes.
11033       switch (i)
11034         {
11035         case elfcpp::Tag_CPU_raw_name:
11036         case elfcpp::Tag_CPU_name:
11037           // These are merged after Tag_CPU_arch.
11038           break;
11039
11040         case elfcpp::Tag_ABI_optimization_goals:
11041         case elfcpp::Tag_ABI_FP_optimization_goals:
11042           // Use the first value seen.
11043           break;
11044
11045         case elfcpp::Tag_CPU_arch:
11046           {
11047             unsigned int saved_out_attr = out_attr->int_value();
11048             // Merge Tag_CPU_arch and Tag_also_compatible_with.
11049             int secondary_compat =
11050               this->get_secondary_compatible_arch(pasd);
11051             int secondary_compat_out =
11052               this->get_secondary_compatible_arch(
11053                   this->attributes_section_data_);
11054             out_attr[i].set_int_value(
11055                 tag_cpu_arch_combine(name, out_attr[i].int_value(),
11056                                      &secondary_compat_out,
11057                                      in_attr[i].int_value(),
11058                                      secondary_compat));
11059             this->set_secondary_compatible_arch(this->attributes_section_data_,
11060                                                 secondary_compat_out);
11061
11062             // Merge Tag_CPU_name and Tag_CPU_raw_name.
11063             if (out_attr[i].int_value() == saved_out_attr)
11064               ; // Leave the names alone.
11065             else if (out_attr[i].int_value() == in_attr[i].int_value())
11066               {
11067                 // The output architecture has been changed to match the
11068                 // input architecture.  Use the input names.
11069                 out_attr[elfcpp::Tag_CPU_name].set_string_value(
11070                     in_attr[elfcpp::Tag_CPU_name].string_value());
11071                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
11072                     in_attr[elfcpp::Tag_CPU_raw_name].string_value());
11073               }
11074             else
11075               {
11076                 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
11077                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
11078               }
11079
11080             // If we still don't have a value for Tag_CPU_name,
11081             // make one up now.  Tag_CPU_raw_name remains blank.
11082             if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
11083               {
11084                 const std::string cpu_name =
11085                   this->tag_cpu_name_value(out_attr[i].int_value());
11086                 // FIXME:  If we see an unknown CPU, this will be set
11087                 // to "<unknown CPU n>", where n is the attribute value.
11088                 // This is different from BFD, which leaves the name alone.
11089                 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
11090               }
11091           }
11092           break;
11093
11094         case elfcpp::Tag_ARM_ISA_use:
11095         case elfcpp::Tag_THUMB_ISA_use:
11096         case elfcpp::Tag_WMMX_arch:
11097         case elfcpp::Tag_Advanced_SIMD_arch:
11098           // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
11099         case elfcpp::Tag_ABI_FP_rounding:
11100         case elfcpp::Tag_ABI_FP_exceptions:
11101         case elfcpp::Tag_ABI_FP_user_exceptions:
11102         case elfcpp::Tag_ABI_FP_number_model:
11103         case elfcpp::Tag_VFP_HP_extension:
11104         case elfcpp::Tag_CPU_unaligned_access:
11105         case elfcpp::Tag_T2EE_use:
11106         case elfcpp::Tag_Virtualization_use:
11107         case elfcpp::Tag_MPextension_use:
11108           // Use the largest value specified.
11109           if (in_attr[i].int_value() > out_attr[i].int_value())
11110             out_attr[i].set_int_value(in_attr[i].int_value());
11111           break;
11112
11113         case elfcpp::Tag_ABI_align8_preserved:
11114         case elfcpp::Tag_ABI_PCS_RO_data:
11115           // Use the smallest value specified.
11116           if (in_attr[i].int_value() < out_attr[i].int_value())
11117             out_attr[i].set_int_value(in_attr[i].int_value());
11118           break;
11119
11120         case elfcpp::Tag_ABI_align8_needed:
11121           if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
11122               && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
11123                   || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
11124                       == 0)))
11125             {
11126               // This error message should be enabled once all non-conforming
11127               // binaries in the toolchain have had the attributes set
11128               // properly.
11129               // gold_error(_("output 8-byte data alignment conflicts with %s"),
11130               //            name);
11131             }
11132           // Fall through.
11133         case elfcpp::Tag_ABI_FP_denormal:
11134         case elfcpp::Tag_ABI_PCS_GOT_use:
11135           {
11136             // These tags have 0 = don't care, 1 = strong requirement,
11137             // 2 = weak requirement.
11138             static const int order_021[3] = {0, 2, 1};
11139
11140             // Use the "greatest" from the sequence 0, 2, 1, or the largest
11141             // value if greater than 2 (for future-proofing).
11142             if ((in_attr[i].int_value() > 2
11143                  && in_attr[i].int_value() > out_attr[i].int_value())
11144                 || (in_attr[i].int_value() <= 2
11145                     && out_attr[i].int_value() <= 2
11146                     && (order_021[in_attr[i].int_value()]
11147                         > order_021[out_attr[i].int_value()])))
11148               out_attr[i].set_int_value(in_attr[i].int_value());
11149           }
11150           break;
11151
11152         case elfcpp::Tag_CPU_arch_profile:
11153           if (out_attr[i].int_value() != in_attr[i].int_value())
11154             {
11155               // 0 will merge with anything.
11156               // 'A' and 'S' merge to 'A'.
11157               // 'R' and 'S' merge to 'R'.
11158               // 'M' and 'A|R|S' is an error.
11159               if (out_attr[i].int_value() == 0
11160                   || (out_attr[i].int_value() == 'S'
11161                       && (in_attr[i].int_value() == 'A'
11162                           || in_attr[i].int_value() == 'R')))
11163                 out_attr[i].set_int_value(in_attr[i].int_value());
11164               else if (in_attr[i].int_value() == 0
11165                        || (in_attr[i].int_value() == 'S'
11166                            && (out_attr[i].int_value() == 'A'
11167                                || out_attr[i].int_value() == 'R')))
11168                 ; // Do nothing.
11169               else if (parameters->options().warn_mismatch())
11170                 {
11171                   gold_error
11172                     (_("conflicting architecture profiles %c/%c"),
11173                      in_attr[i].int_value() ? in_attr[i].int_value() : '0',
11174                      out_attr[i].int_value() ? out_attr[i].int_value() : '0');
11175                 }
11176             }
11177           break;
11178         case elfcpp::Tag_VFP_arch:
11179             {
11180               static const struct
11181               {
11182                   int ver;
11183                   int regs;
11184               } vfp_versions[7] =
11185                 {
11186                   {0, 0},
11187                   {1, 16},
11188                   {2, 16},
11189                   {3, 32},
11190                   {3, 16},
11191                   {4, 32},
11192                   {4, 16}
11193                 };
11194
11195               // Values greater than 6 aren't defined, so just pick the
11196               // biggest.
11197               if (in_attr[i].int_value() > 6
11198                   && in_attr[i].int_value() > out_attr[i].int_value())
11199                 {
11200                   *out_attr = *in_attr;
11201                   break;
11202                 }
11203               // The output uses the superset of input features
11204               // (ISA version) and registers.
11205               int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
11206                                  vfp_versions[out_attr[i].int_value()].ver);
11207               int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
11208                                   vfp_versions[out_attr[i].int_value()].regs);
11209               // This assumes all possible supersets are also a valid
11210               // options.
11211               int newval;
11212               for (newval = 6; newval > 0; newval--)
11213                 {
11214                   if (regs == vfp_versions[newval].regs
11215                       && ver == vfp_versions[newval].ver)
11216                     break;
11217                 }
11218               out_attr[i].set_int_value(newval);
11219             }
11220           break;
11221         case elfcpp::Tag_PCS_config:
11222           if (out_attr[i].int_value() == 0)
11223             out_attr[i].set_int_value(in_attr[i].int_value());
11224           else if (in_attr[i].int_value() != 0
11225                    && out_attr[i].int_value() != 0
11226                    && parameters->options().warn_mismatch())
11227             {
11228               // It's sometimes ok to mix different configs, so this is only
11229               // a warning.
11230               gold_warning(_("%s: conflicting platform configuration"), name);
11231             }
11232           break;
11233         case elfcpp::Tag_ABI_PCS_R9_use:
11234           if (in_attr[i].int_value() != out_attr[i].int_value()
11235               && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
11236               && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
11237               && parameters->options().warn_mismatch())
11238             {
11239               gold_error(_("%s: conflicting use of R9"), name);
11240             }
11241           if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
11242             out_attr[i].set_int_value(in_attr[i].int_value());
11243           break;
11244         case elfcpp::Tag_ABI_PCS_RW_data:
11245           if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
11246               && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
11247                   != elfcpp::AEABI_R9_SB)
11248               && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
11249                   != elfcpp::AEABI_R9_unused)
11250               && parameters->options().warn_mismatch())
11251             {
11252               gold_error(_("%s: SB relative addressing conflicts with use "
11253                            "of R9"),
11254                            name);
11255             }
11256           // Use the smallest value specified.
11257           if (in_attr[i].int_value() < out_attr[i].int_value())
11258             out_attr[i].set_int_value(in_attr[i].int_value());
11259           break;
11260         case elfcpp::Tag_ABI_PCS_wchar_t:
11261           if (out_attr[i].int_value()
11262               && in_attr[i].int_value()
11263               && out_attr[i].int_value() != in_attr[i].int_value()
11264               && parameters->options().warn_mismatch()
11265               && parameters->options().wchar_size_warning())
11266             {
11267               gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
11268                              "use %u-byte wchar_t; use of wchar_t values "
11269                              "across objects may fail"),
11270                            name, in_attr[i].int_value(),
11271                            out_attr[i].int_value());
11272             }
11273           else if (in_attr[i].int_value() && !out_attr[i].int_value())
11274             out_attr[i].set_int_value(in_attr[i].int_value());
11275           break;
11276         case elfcpp::Tag_ABI_enum_size:
11277           if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
11278             {
11279               if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
11280                   || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
11281                 {
11282                   // The existing object is compatible with anything.
11283                   // Use whatever requirements the new object has.
11284                   out_attr[i].set_int_value(in_attr[i].int_value());
11285                 }
11286               else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
11287                        && out_attr[i].int_value() != in_attr[i].int_value()
11288                        && parameters->options().warn_mismatch()
11289                        && parameters->options().enum_size_warning())
11290                 {
11291                   unsigned int in_value = in_attr[i].int_value();
11292                   unsigned int out_value = out_attr[i].int_value();
11293                   gold_warning(_("%s uses %s enums yet the output is to use "
11294                                  "%s enums; use of enum values across objects "
11295                                  "may fail"),
11296                                name,
11297                                this->aeabi_enum_name(in_value).c_str(),
11298                                this->aeabi_enum_name(out_value).c_str());
11299                 }
11300             }
11301           break;
11302         case elfcpp::Tag_ABI_VFP_args:
11303           // Already done.
11304           break;
11305         case elfcpp::Tag_ABI_WMMX_args:
11306           if (in_attr[i].int_value() != out_attr[i].int_value()
11307               && parameters->options().warn_mismatch())
11308             {
11309               gold_error(_("%s uses iWMMXt register arguments, output does "
11310                            "not"),
11311                          name);
11312             }
11313           break;
11314         case Object_attribute::Tag_compatibility:
11315           // Merged in target-independent code.
11316           break;
11317         case elfcpp::Tag_ABI_HardFP_use:
11318           // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
11319           if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
11320               || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
11321             out_attr[i].set_int_value(3);
11322           else if (in_attr[i].int_value() > out_attr[i].int_value())
11323             out_attr[i].set_int_value(in_attr[i].int_value());
11324           break;
11325         case elfcpp::Tag_ABI_FP_16bit_format:
11326           if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
11327             {
11328               if (in_attr[i].int_value() != out_attr[i].int_value()
11329                   && parameters->options().warn_mismatch())
11330                 gold_error(_("fp16 format mismatch between %s and output"),
11331                            name);
11332             }
11333           if (in_attr[i].int_value() != 0)
11334             out_attr[i].set_int_value(in_attr[i].int_value());
11335           break;
11336
11337         case elfcpp::Tag_DIV_use:
11338           {
11339             // A value of zero on input means that the divide
11340             // instruction may be used if available in the base
11341             // architecture as specified via Tag_CPU_arch and
11342             // Tag_CPU_arch_profile.  A value of 1 means that the user
11343             // did not want divide instructions.  A value of 2
11344             // explicitly means that divide instructions were allowed
11345             // in ARM and Thumb state.
11346             int arch = this->
11347               get_aeabi_object_attribute(elfcpp::Tag_CPU_arch)->
11348               int_value();
11349             int profile = this->
11350               get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile)->
11351               int_value();
11352             if (in_attr[i].int_value() == out_attr[i].int_value())
11353               {
11354                 // Do nothing.
11355               }
11356             else if (attributes_forbid_div(&in_attr[i])
11357                      && !attributes_accept_div(arch, profile, &out_attr[i]))
11358               out_attr[i].set_int_value(1);
11359             else if (attributes_forbid_div(&out_attr[i])
11360                      && attributes_accept_div(arch, profile, &in_attr[i]))
11361               out_attr[i].set_int_value(in_attr[i].int_value());
11362             else if (in_attr[i].int_value() == 2)
11363               out_attr[i].set_int_value(in_attr[i].int_value());
11364           }
11365           break;
11366
11367         case elfcpp::Tag_MPextension_use_legacy:
11368           // We don't output objects with Tag_MPextension_use_legacy - we
11369           // move the value to Tag_MPextension_use.
11370           if (in_attr[i].int_value() != 0
11371               && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
11372             {
11373               if (in_attr[elfcpp::Tag_MPextension_use].int_value()
11374                   != in_attr[i].int_value())
11375                 {
11376                   gold_error(_("%s has has both the current and legacy "
11377                                "Tag_MPextension_use attributes"),
11378                              name);
11379                 }
11380             }
11381
11382           if (in_attr[i].int_value()
11383               > out_attr[elfcpp::Tag_MPextension_use].int_value())
11384             out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
11385
11386           break;
11387
11388         case elfcpp::Tag_nodefaults:
11389           // This tag is set if it exists, but the value is unused (and is
11390           // typically zero).  We don't actually need to do anything here -
11391           // the merge happens automatically when the type flags are merged
11392           // below.
11393           break;
11394         case elfcpp::Tag_also_compatible_with:
11395           // Already done in Tag_CPU_arch.
11396           break;
11397         case elfcpp::Tag_conformance:
11398           // Keep the attribute if it matches.  Throw it away otherwise.
11399           // No attribute means no claim to conform.
11400           if (in_attr[i].string_value() != out_attr[i].string_value())
11401             out_attr[i].set_string_value("");
11402           break;
11403
11404         default:
11405           {
11406             const char* err_object = NULL;
11407
11408             // The "known_obj_attributes" table does contain some undefined
11409             // attributes.  Ensure that there are unused.
11410             if (out_attr[i].int_value() != 0
11411                 || out_attr[i].string_value() != "")
11412               err_object = "output";
11413             else if (in_attr[i].int_value() != 0
11414                      || in_attr[i].string_value() != "")
11415               err_object = name;
11416
11417             if (err_object != NULL
11418                 && parameters->options().warn_mismatch())
11419               {
11420                 // Attribute numbers >=64 (mod 128) can be safely ignored.
11421                 if ((i & 127) < 64)
11422                   gold_error(_("%s: unknown mandatory EABI object attribute "
11423                                "%d"),
11424                              err_object, i);
11425                 else
11426                   gold_warning(_("%s: unknown EABI object attribute %d"),
11427                                err_object, i);
11428               }
11429
11430             // Only pass on attributes that match in both inputs.
11431             if (!in_attr[i].matches(out_attr[i]))
11432               {
11433                 out_attr[i].set_int_value(0);
11434                 out_attr[i].set_string_value("");
11435               }
11436           }
11437         }
11438
11439       // If out_attr was copied from in_attr then it won't have a type yet.
11440       if (in_attr[i].type() && !out_attr[i].type())
11441         out_attr[i].set_type(in_attr[i].type());
11442     }
11443
11444   // Merge Tag_compatibility attributes and any common GNU ones.
11445   this->attributes_section_data_->merge(name, pasd);
11446
11447   // Check for any attributes not known on ARM.
11448   typedef Vendor_object_attributes::Other_attributes Other_attributes;
11449   const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
11450   Other_attributes::const_iterator in_iter = in_other_attributes->begin();
11451   Other_attributes* out_other_attributes =
11452     this->attributes_section_data_->other_attributes(vendor);
11453   Other_attributes::iterator out_iter = out_other_attributes->begin();
11454
11455   while (in_iter != in_other_attributes->end()
11456          || out_iter != out_other_attributes->end())
11457     {
11458       const char* err_object = NULL;
11459       int err_tag = 0;
11460
11461       // The tags for each list are in numerical order.
11462       // If the tags are equal, then merge.
11463       if (out_iter != out_other_attributes->end()
11464           && (in_iter == in_other_attributes->end()
11465               || in_iter->first > out_iter->first))
11466         {
11467           // This attribute only exists in output.  We can't merge, and we
11468           // don't know what the tag means, so delete it.
11469           err_object = "output";
11470           err_tag = out_iter->first;
11471           int saved_tag = out_iter->first;
11472           delete out_iter->second;
11473           out_other_attributes->erase(out_iter);
11474           out_iter = out_other_attributes->upper_bound(saved_tag);
11475         }
11476       else if (in_iter != in_other_attributes->end()
11477                && (out_iter != out_other_attributes->end()
11478                    || in_iter->first < out_iter->first))
11479         {
11480           // This attribute only exists in input. We can't merge, and we
11481           // don't know what the tag means, so ignore it.
11482           err_object = name;
11483           err_tag = in_iter->first;
11484           ++in_iter;
11485         }
11486       else // The tags are equal.
11487         {
11488           // As present, all attributes in the list are unknown, and
11489           // therefore can't be merged meaningfully.
11490           err_object = "output";
11491           err_tag = out_iter->first;
11492
11493           //  Only pass on attributes that match in both inputs.
11494           if (!in_iter->second->matches(*(out_iter->second)))
11495             {
11496               // No match.  Delete the attribute.
11497               int saved_tag = out_iter->first;
11498               delete out_iter->second;
11499               out_other_attributes->erase(out_iter);
11500               out_iter = out_other_attributes->upper_bound(saved_tag);
11501             }
11502           else
11503             {
11504               // Matched.  Keep the attribute and move to the next.
11505               ++out_iter;
11506               ++in_iter;
11507             }
11508         }
11509
11510       if (err_object && parameters->options().warn_mismatch())
11511         {
11512           // Attribute numbers >=64 (mod 128) can be safely ignored.  */
11513           if ((err_tag & 127) < 64)
11514             {
11515               gold_error(_("%s: unknown mandatory EABI object attribute %d"),
11516                          err_object, err_tag);
11517             }
11518           else
11519             {
11520               gold_warning(_("%s: unknown EABI object attribute %d"),
11521                            err_object, err_tag);
11522             }
11523         }
11524     }
11525 }
11526
11527 // Stub-generation methods for Target_arm.
11528
11529 // Make a new Arm_input_section object.
11530
11531 template<bool big_endian>
11532 Arm_input_section<big_endian>*
11533 Target_arm<big_endian>::new_arm_input_section(
11534     Relobj* relobj,
11535     unsigned int shndx)
11536 {
11537   Section_id sid(relobj, shndx);
11538
11539   Arm_input_section<big_endian>* arm_input_section =
11540     new Arm_input_section<big_endian>(relobj, shndx);
11541   arm_input_section->init();
11542
11543   // Register new Arm_input_section in map for look-up.
11544   std::pair<typename Arm_input_section_map::iterator, bool> ins =
11545     this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
11546
11547   // Make sure that it we have not created another Arm_input_section
11548   // for this input section already.
11549   gold_assert(ins.second);
11550
11551   return arm_input_section;
11552 }
11553
11554 // Find the Arm_input_section object corresponding to the SHNDX-th input
11555 // section of RELOBJ.
11556
11557 template<bool big_endian>
11558 Arm_input_section<big_endian>*
11559 Target_arm<big_endian>::find_arm_input_section(
11560     Relobj* relobj,
11561     unsigned int shndx) const
11562 {
11563   Section_id sid(relobj, shndx);
11564   typename Arm_input_section_map::const_iterator p =
11565     this->arm_input_section_map_.find(sid);
11566   return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
11567 }
11568
11569 // Make a new stub table.
11570
11571 template<bool big_endian>
11572 Stub_table<big_endian>*
11573 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
11574 {
11575   Stub_table<big_endian>* stub_table =
11576     new Stub_table<big_endian>(owner);
11577   this->stub_tables_.push_back(stub_table);
11578
11579   stub_table->set_address(owner->address() + owner->data_size());
11580   stub_table->set_file_offset(owner->offset() + owner->data_size());
11581   stub_table->finalize_data_size();
11582
11583   return stub_table;
11584 }
11585
11586 // Scan a relocation for stub generation.
11587
11588 template<bool big_endian>
11589 void
11590 Target_arm<big_endian>::scan_reloc_for_stub(
11591     const Relocate_info<32, big_endian>* relinfo,
11592     unsigned int r_type,
11593     const Sized_symbol<32>* gsym,
11594     unsigned int r_sym,
11595     const Symbol_value<32>* psymval,
11596     elfcpp::Elf_types<32>::Elf_Swxword addend,
11597     Arm_address address)
11598 {
11599   const Arm_relobj<big_endian>* arm_relobj =
11600     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11601
11602   bool target_is_thumb;
11603   Symbol_value<32> symval;
11604   if (gsym != NULL)
11605     {
11606       // This is a global symbol.  Determine if we use PLT and if the
11607       // final target is THUMB.
11608       if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
11609         {
11610           // This uses a PLT, change the symbol value.
11611           symval.set_output_value(this->plt_address_for_global(gsym));
11612           psymval = &symval;
11613           target_is_thumb = false;
11614         }
11615       else if (gsym->is_undefined())
11616         // There is no need to generate a stub symbol is undefined.
11617         return;
11618       else
11619         {
11620           target_is_thumb =
11621             ((gsym->type() == elfcpp::STT_ARM_TFUNC)
11622              || (gsym->type() == elfcpp::STT_FUNC
11623                  && !gsym->is_undefined()
11624                  && ((psymval->value(arm_relobj, 0) & 1) != 0)));
11625         }
11626     }
11627   else
11628     {
11629       // This is a local symbol.  Determine if the final target is THUMB.
11630       target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
11631     }
11632
11633   // Strip LSB if this points to a THUMB target.
11634   const Arm_reloc_property* reloc_property =
11635     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
11636   gold_assert(reloc_property != NULL);
11637   if (target_is_thumb
11638       && reloc_property->uses_thumb_bit()
11639       && ((psymval->value(arm_relobj, 0) & 1) != 0))
11640     {
11641       Arm_address stripped_value =
11642         psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
11643       symval.set_output_value(stripped_value);
11644       psymval = &symval;
11645     }
11646
11647   // Get the symbol value.
11648   Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
11649
11650   // Owing to pipelining, the PC relative branches below actually skip
11651   // two instructions when the branch offset is 0.
11652   Arm_address destination;
11653   switch (r_type)
11654     {
11655     case elfcpp::R_ARM_CALL:
11656     case elfcpp::R_ARM_JUMP24:
11657     case elfcpp::R_ARM_PLT32:
11658       // ARM branches.
11659       destination = value + addend + 8;
11660       break;
11661     case elfcpp::R_ARM_THM_CALL:
11662     case elfcpp::R_ARM_THM_XPC22:
11663     case elfcpp::R_ARM_THM_JUMP24:
11664     case elfcpp::R_ARM_THM_JUMP19:
11665       // THUMB branches.
11666       destination = value + addend + 4;
11667       break;
11668     default:
11669       gold_unreachable();
11670     }
11671
11672   Reloc_stub* stub = NULL;
11673   Stub_type stub_type =
11674     Reloc_stub::stub_type_for_reloc(r_type, address, destination,
11675                                     target_is_thumb);
11676   if (stub_type != arm_stub_none)
11677     {
11678       // Try looking up an existing stub from a stub table.
11679       Stub_table<big_endian>* stub_table =
11680         arm_relobj->stub_table(relinfo->data_shndx);
11681       gold_assert(stub_table != NULL);
11682
11683       // Locate stub by destination.
11684       Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
11685
11686       // Create a stub if there is not one already
11687       stub = stub_table->find_reloc_stub(stub_key);
11688       if (stub == NULL)
11689         {
11690           // create a new stub and add it to stub table.
11691           stub = this->stub_factory().make_reloc_stub(stub_type);
11692           stub_table->add_reloc_stub(stub, stub_key);
11693         }
11694
11695       // Record the destination address.
11696       stub->set_destination_address(destination
11697                                     | (target_is_thumb ? 1 : 0));
11698     }
11699
11700   // For Cortex-A8, we need to record a relocation at 4K page boundary.
11701   if (this->fix_cortex_a8_
11702       && (r_type == elfcpp::R_ARM_THM_JUMP24
11703           || r_type == elfcpp::R_ARM_THM_JUMP19
11704           || r_type == elfcpp::R_ARM_THM_CALL
11705           || r_type == elfcpp::R_ARM_THM_XPC22)
11706       && (address & 0xfffU) == 0xffeU)
11707     {
11708       // Found a candidate.  Note we haven't checked the destination is
11709       // within 4K here: if we do so (and don't create a record) we can't
11710       // tell that a branch should have been relocated when scanning later.
11711       this->cortex_a8_relocs_info_[address] =
11712         new Cortex_a8_reloc(stub, r_type,
11713                             destination | (target_is_thumb ? 1 : 0));
11714     }
11715 }
11716
11717 // This function scans a relocation sections for stub generation.
11718 // The template parameter Relocate must be a class type which provides
11719 // a single function, relocate(), which implements the machine
11720 // specific part of a relocation.
11721
11722 // BIG_ENDIAN is the endianness of the data.  SH_TYPE is the section type:
11723 // SHT_REL or SHT_RELA.
11724
11725 // PRELOCS points to the relocation data.  RELOC_COUNT is the number
11726 // of relocs.  OUTPUT_SECTION is the output section.
11727 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
11728 // mapped to output offsets.
11729
11730 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
11731 // VIEW_SIZE is the size.  These refer to the input section, unless
11732 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
11733 // the output section.
11734
11735 template<bool big_endian>
11736 template<int sh_type>
11737 void inline
11738 Target_arm<big_endian>::scan_reloc_section_for_stubs(
11739     const Relocate_info<32, big_endian>* relinfo,
11740     const unsigned char* prelocs,
11741     size_t reloc_count,
11742     Output_section* output_section,
11743     bool needs_special_offset_handling,
11744     const unsigned char* view,
11745     elfcpp::Elf_types<32>::Elf_Addr view_address,
11746     section_size_type)
11747 {
11748   typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
11749   const int reloc_size =
11750     Reloc_types<sh_type, 32, big_endian>::reloc_size;
11751
11752   Arm_relobj<big_endian>* arm_object =
11753     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11754   unsigned int local_count = arm_object->local_symbol_count();
11755
11756   gold::Default_comdat_behavior default_comdat_behavior;
11757   Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11758
11759   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11760     {
11761       Reltype reloc(prelocs);
11762
11763       typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11764       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11765       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11766
11767       r_type = this->get_real_reloc_type(r_type);
11768
11769       // Only a few relocation types need stubs.
11770       if ((r_type != elfcpp::R_ARM_CALL)
11771          && (r_type != elfcpp::R_ARM_JUMP24)
11772          && (r_type != elfcpp::R_ARM_PLT32)
11773          && (r_type != elfcpp::R_ARM_THM_CALL)
11774          && (r_type != elfcpp::R_ARM_THM_XPC22)
11775          && (r_type != elfcpp::R_ARM_THM_JUMP24)
11776          && (r_type != elfcpp::R_ARM_THM_JUMP19)
11777          && (r_type != elfcpp::R_ARM_V4BX))
11778         continue;
11779
11780       section_offset_type offset =
11781         convert_to_section_size_type(reloc.get_r_offset());
11782
11783       if (needs_special_offset_handling)
11784         {
11785           offset = output_section->output_offset(relinfo->object,
11786                                                  relinfo->data_shndx,
11787                                                  offset);
11788           if (offset == -1)
11789             continue;
11790         }
11791
11792       // Create a v4bx stub if --fix-v4bx-interworking is used.
11793       if (r_type == elfcpp::R_ARM_V4BX)
11794         {
11795           if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11796             {
11797               // Get the BX instruction.
11798               typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11799               const Valtype* wv =
11800                 reinterpret_cast<const Valtype*>(view + offset);
11801               elfcpp::Elf_types<32>::Elf_Swxword insn =
11802                 elfcpp::Swap<32, big_endian>::readval(wv);
11803               const uint32_t reg = (insn & 0xf);
11804
11805               if (reg < 0xf)
11806                 {
11807                   // Try looking up an existing stub from a stub table.
11808                   Stub_table<big_endian>* stub_table =
11809                     arm_object->stub_table(relinfo->data_shndx);
11810                   gold_assert(stub_table != NULL);
11811
11812                   if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11813                     {
11814                       // create a new stub and add it to stub table.
11815                       Arm_v4bx_stub* stub =
11816                         this->stub_factory().make_arm_v4bx_stub(reg);
11817                       gold_assert(stub != NULL);
11818                       stub_table->add_arm_v4bx_stub(stub);
11819                     }
11820                 }
11821             }
11822           continue;
11823         }
11824
11825       // Get the addend.
11826       Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11827       elfcpp::Elf_types<32>::Elf_Swxword addend =
11828         stub_addend_reader(r_type, view + offset, reloc);
11829
11830       const Sized_symbol<32>* sym;
11831
11832       Symbol_value<32> symval;
11833       const Symbol_value<32> *psymval;
11834       bool is_defined_in_discarded_section;
11835       unsigned int shndx;
11836       if (r_sym < local_count)
11837         {
11838           sym = NULL;
11839           psymval = arm_object->local_symbol(r_sym);
11840
11841           // If the local symbol belongs to a section we are discarding,
11842           // and that section is a debug section, try to find the
11843           // corresponding kept section and map this symbol to its
11844           // counterpart in the kept section.  The symbol must not
11845           // correspond to a section we are folding.
11846           bool is_ordinary;
11847           shndx = psymval->input_shndx(&is_ordinary);
11848           is_defined_in_discarded_section =
11849             (is_ordinary
11850              && shndx != elfcpp::SHN_UNDEF
11851              && !arm_object->is_section_included(shndx)
11852              && !relinfo->symtab->is_section_folded(arm_object, shndx));
11853
11854           // We need to compute the would-be final value of this local
11855           // symbol.
11856           if (!is_defined_in_discarded_section)
11857             {
11858               typedef Sized_relobj_file<32, big_endian> ObjType;
11859               typename ObjType::Compute_final_local_value_status status =
11860                 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11861                                                       relinfo->symtab);
11862               if (status == ObjType::CFLV_OK)
11863                 {
11864                   // Currently we cannot handle a branch to a target in
11865                   // a merged section.  If this is the case, issue an error
11866                   // and also free the merge symbol value.
11867                   if (!symval.has_output_value())
11868                     {
11869                       const std::string& section_name =
11870                         arm_object->section_name(shndx);
11871                       arm_object->error(_("cannot handle branch to local %u "
11872                                           "in a merged section %s"),
11873                                         r_sym, section_name.c_str());
11874                     }
11875                   psymval = &symval;
11876                 }
11877               else
11878                 {
11879                   // We cannot determine the final value.
11880                   continue;
11881                 }
11882             }
11883         }
11884       else
11885         {
11886           const Symbol* gsym;
11887           gsym = arm_object->global_symbol(r_sym);
11888           gold_assert(gsym != NULL);
11889           if (gsym->is_forwarder())
11890             gsym = relinfo->symtab->resolve_forwards(gsym);
11891
11892           sym = static_cast<const Sized_symbol<32>*>(gsym);
11893           if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11894             symval.set_output_symtab_index(sym->symtab_index());
11895           else
11896             symval.set_no_output_symtab_entry();
11897
11898           // We need to compute the would-be final value of this global
11899           // symbol.
11900           const Symbol_table* symtab = relinfo->symtab;
11901           const Sized_symbol<32>* sized_symbol =
11902             symtab->get_sized_symbol<32>(gsym);
11903           Symbol_table::Compute_final_value_status status;
11904           Arm_address value =
11905             symtab->compute_final_value<32>(sized_symbol, &status);
11906
11907           // Skip this if the symbol has not output section.
11908           if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11909             continue;
11910           symval.set_output_value(value);
11911
11912           if (gsym->type() == elfcpp::STT_TLS)
11913             symval.set_is_tls_symbol();
11914           else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11915             symval.set_is_ifunc_symbol();
11916           psymval = &symval;
11917
11918           is_defined_in_discarded_section =
11919             (gsym->is_defined_in_discarded_section()
11920              && gsym->is_undefined());
11921           shndx = 0;
11922         }
11923
11924       Symbol_value<32> symval2;
11925       if (is_defined_in_discarded_section)
11926         {
11927           if (comdat_behavior == CB_UNDETERMINED)
11928             {
11929               std::string name = arm_object->section_name(relinfo->data_shndx);
11930               comdat_behavior = default_comdat_behavior.get(name.c_str());
11931             }
11932           if (comdat_behavior == CB_PRETEND)
11933             {
11934               // FIXME: This case does not work for global symbols.
11935               // We have no place to store the original section index.
11936               // Fortunately this does not matter for comdat sections,
11937               // only for sections explicitly discarded by a linker
11938               // script.
11939               bool found;
11940               typename elfcpp::Elf_types<32>::Elf_Addr value =
11941                 arm_object->map_to_kept_section(shndx, &found);
11942               if (found)
11943                 symval2.set_output_value(value + psymval->input_value());
11944               else
11945                 symval2.set_output_value(0);
11946             }
11947           else
11948             {
11949               if (comdat_behavior == CB_WARNING)
11950                 gold_warning_at_location(relinfo, i, offset,
11951                                          _("relocation refers to discarded "
11952                                            "section"));
11953               symval2.set_output_value(0);
11954             }
11955           symval2.set_no_output_symtab_entry();
11956           psymval = &symval2;
11957         }
11958
11959       // If symbol is a section symbol, we don't know the actual type of
11960       // destination.  Give up.
11961       if (psymval->is_section_symbol())
11962         continue;
11963
11964       this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11965                                 addend, view_address + offset);
11966     }
11967 }
11968
11969 // Scan an input section for stub generation.
11970
11971 template<bool big_endian>
11972 void
11973 Target_arm<big_endian>::scan_section_for_stubs(
11974     const Relocate_info<32, big_endian>* relinfo,
11975     unsigned int sh_type,
11976     const unsigned char* prelocs,
11977     size_t reloc_count,
11978     Output_section* output_section,
11979     bool needs_special_offset_handling,
11980     const unsigned char* view,
11981     Arm_address view_address,
11982     section_size_type view_size)
11983 {
11984   if (sh_type == elfcpp::SHT_REL)
11985     this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11986         relinfo,
11987         prelocs,
11988         reloc_count,
11989         output_section,
11990         needs_special_offset_handling,
11991         view,
11992         view_address,
11993         view_size);
11994   else if (sh_type == elfcpp::SHT_RELA)
11995     // We do not support RELA type relocations yet.  This is provided for
11996     // completeness.
11997     this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11998         relinfo,
11999         prelocs,
12000         reloc_count,
12001         output_section,
12002         needs_special_offset_handling,
12003         view,
12004         view_address,
12005         view_size);
12006   else
12007     gold_unreachable();
12008 }
12009
12010 // Group input sections for stub generation.
12011 //
12012 // We group input sections in an output section so that the total size,
12013 // including any padding space due to alignment is smaller than GROUP_SIZE
12014 // unless the only input section in group is bigger than GROUP_SIZE already.
12015 // Then an ARM stub table is created to follow the last input section
12016 // in group.  For each group an ARM stub table is created an is placed
12017 // after the last group.  If STUB_ALWAYS_AFTER_BRANCH is false, we further
12018 // extend the group after the stub table.
12019
12020 template<bool big_endian>
12021 void
12022 Target_arm<big_endian>::group_sections(
12023     Layout* layout,
12024     section_size_type group_size,
12025     bool stubs_always_after_branch,
12026     const Task* task)
12027 {
12028   // Group input sections and insert stub table
12029   Layout::Section_list section_list;
12030   layout->get_executable_sections(&section_list);
12031   for (Layout::Section_list::const_iterator p = section_list.begin();
12032        p != section_list.end();
12033        ++p)
12034     {
12035       Arm_output_section<big_endian>* output_section =
12036         Arm_output_section<big_endian>::as_arm_output_section(*p);
12037       output_section->group_sections(group_size, stubs_always_after_branch,
12038                                      this, task);
12039     }
12040 }
12041
12042 // Relaxation hook.  This is where we do stub generation.
12043
12044 template<bool big_endian>
12045 bool
12046 Target_arm<big_endian>::do_relax(
12047     int pass,
12048     const Input_objects* input_objects,
12049     Symbol_table* symtab,
12050     Layout* layout,
12051     const Task* task)
12052 {
12053   // No need to generate stubs if this is a relocatable link.
12054   gold_assert(!parameters->options().relocatable());
12055
12056   // If this is the first pass, we need to group input sections into
12057   // stub groups.
12058   bool done_exidx_fixup = false;
12059   typedef typename Stub_table_list::iterator Stub_table_iterator;
12060   if (pass == 1)
12061     {
12062       // Determine the stub group size.  The group size is the absolute
12063       // value of the parameter --stub-group-size.  If --stub-group-size
12064       // is passed a negative value, we restrict stubs to be always after
12065       // the stubbed branches.
12066       int32_t stub_group_size_param =
12067         parameters->options().stub_group_size();
12068       bool stubs_always_after_branch = stub_group_size_param < 0;
12069       section_size_type stub_group_size = abs(stub_group_size_param);
12070
12071       if (stub_group_size == 1)
12072         {
12073           // Default value.
12074           // Thumb branch range is +-4MB has to be used as the default
12075           // maximum size (a given section can contain both ARM and Thumb
12076           // code, so the worst case has to be taken into account).  If we are
12077           // fixing cortex-a8 errata, the branch range has to be even smaller,
12078           // since wide conditional branch has a range of +-1MB only.
12079           //
12080           // This value is 48K less than that, which allows for 4096
12081           // 12-byte stubs.  If we exceed that, then we will fail to link.
12082           // The user will have to relink with an explicit group size
12083           // option.
12084             stub_group_size = 4145152;
12085         }
12086
12087       // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
12088       // page as the first half of a 32-bit branch straddling two 4K pages.
12089       // This is a crude way of enforcing that.  In addition, long conditional
12090       // branches of THUMB-2 have a range of +-1M.  If we are fixing cortex-A8
12091       // erratum, limit the group size to  (1M - 12k) to avoid unreachable
12092       // cortex-A8 stubs from long conditional branches.
12093       if (this->fix_cortex_a8_)
12094         {
12095           stubs_always_after_branch = true;
12096           const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
12097           stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
12098         }
12099
12100       group_sections(layout, stub_group_size, stubs_always_after_branch, task);
12101
12102       // Also fix .ARM.exidx section coverage.
12103       Arm_output_section<big_endian>* exidx_output_section = NULL;
12104       for (Layout::Section_list::const_iterator p =
12105              layout->section_list().begin();
12106            p != layout->section_list().end();
12107            ++p)
12108         if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
12109           {
12110             if (exidx_output_section == NULL)
12111               exidx_output_section =
12112                 Arm_output_section<big_endian>::as_arm_output_section(*p);
12113             else
12114               // We cannot handle this now.
12115               gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
12116                            "non-relocatable link"),
12117                           exidx_output_section->name(),
12118                           (*p)->name());
12119           }
12120
12121       if (exidx_output_section != NULL)
12122         {
12123           this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
12124                                    symtab, task);
12125           done_exidx_fixup = true;
12126         }
12127     }
12128   else
12129     {
12130       // If this is not the first pass, addresses and file offsets have
12131       // been reset at this point, set them here.
12132       for (Stub_table_iterator sp = this->stub_tables_.begin();
12133            sp != this->stub_tables_.end();
12134            ++sp)
12135         {
12136           Arm_input_section<big_endian>* owner = (*sp)->owner();
12137           off_t off = align_address(owner->original_size(),
12138                                     (*sp)->addralign());
12139           (*sp)->set_address_and_file_offset(owner->address() + off,
12140                                              owner->offset() + off);
12141         }
12142     }
12143
12144   // The Cortex-A8 stubs are sensitive to layout of code sections.  At the
12145   // beginning of each relaxation pass, just blow away all the stubs.
12146   // Alternatively, we could selectively remove only the stubs and reloc
12147   // information for code sections that have moved since the last pass.
12148   // That would require more book-keeping.
12149   if (this->fix_cortex_a8_)
12150     {
12151       // Clear all Cortex-A8 reloc information.
12152       for (typename Cortex_a8_relocs_info::const_iterator p =
12153              this->cortex_a8_relocs_info_.begin();
12154            p != this->cortex_a8_relocs_info_.end();
12155            ++p)
12156         delete p->second;
12157       this->cortex_a8_relocs_info_.clear();
12158
12159       // Remove all Cortex-A8 stubs.
12160       for (Stub_table_iterator sp = this->stub_tables_.begin();
12161            sp != this->stub_tables_.end();
12162            ++sp)
12163         (*sp)->remove_all_cortex_a8_stubs();
12164     }
12165
12166   // Scan relocs for relocation stubs
12167   for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
12168        op != input_objects->relobj_end();
12169        ++op)
12170     {
12171       Arm_relobj<big_endian>* arm_relobj =
12172         Arm_relobj<big_endian>::as_arm_relobj(*op);
12173       // Lock the object so we can read from it.  This is only called
12174       // single-threaded from Layout::finalize, so it is OK to lock.
12175       Task_lock_obj<Object> tl(task, arm_relobj);
12176       arm_relobj->scan_sections_for_stubs(this, symtab, layout);
12177     }
12178
12179   // Check all stub tables to see if any of them have their data sizes
12180   // or addresses alignments changed.  These are the only things that
12181   // matter.
12182   bool any_stub_table_changed = false;
12183   Unordered_set<const Output_section*> sections_needing_adjustment;
12184   for (Stub_table_iterator sp = this->stub_tables_.begin();
12185        (sp != this->stub_tables_.end()) && !any_stub_table_changed;
12186        ++sp)
12187     {
12188       if ((*sp)->update_data_size_and_addralign())
12189         {
12190           // Update data size of stub table owner.
12191           Arm_input_section<big_endian>* owner = (*sp)->owner();
12192           uint64_t address = owner->address();
12193           off_t offset = owner->offset();
12194           owner->reset_address_and_file_offset();
12195           owner->set_address_and_file_offset(address, offset);
12196
12197           sections_needing_adjustment.insert(owner->output_section());
12198           any_stub_table_changed = true;
12199         }
12200     }
12201
12202   // Output_section_data::output_section() returns a const pointer but we
12203   // need to update output sections, so we record all output sections needing
12204   // update above and scan the sections here to find out what sections need
12205   // to be updated.
12206   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
12207       p != layout->section_list().end();
12208       ++p)
12209     {
12210       if (sections_needing_adjustment.find(*p)
12211           != sections_needing_adjustment.end())
12212         (*p)->set_section_offsets_need_adjustment();
12213     }
12214
12215   // Stop relaxation if no EXIDX fix-up and no stub table change.
12216   bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
12217
12218   // Finalize the stubs in the last relaxation pass.
12219   if (!continue_relaxation)
12220     {
12221       for (Stub_table_iterator sp = this->stub_tables_.begin();
12222            (sp != this->stub_tables_.end()) && !any_stub_table_changed;
12223             ++sp)
12224         (*sp)->finalize_stubs();
12225
12226       // Update output local symbol counts of objects if necessary.
12227       for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
12228            op != input_objects->relobj_end();
12229            ++op)
12230         {
12231           Arm_relobj<big_endian>* arm_relobj =
12232             Arm_relobj<big_endian>::as_arm_relobj(*op);
12233
12234           // Update output local symbol counts.  We need to discard local
12235           // symbols defined in parts of input sections that are discarded by
12236           // relaxation.
12237           if (arm_relobj->output_local_symbol_count_needs_update())
12238             {
12239               // We need to lock the object's file to update it.
12240               Task_lock_obj<Object> tl(task, arm_relobj);
12241               arm_relobj->update_output_local_symbol_count();
12242             }
12243         }
12244     }
12245
12246   return continue_relaxation;
12247 }
12248
12249 // Relocate a stub.
12250
12251 template<bool big_endian>
12252 void
12253 Target_arm<big_endian>::relocate_stub(
12254     Stub* stub,
12255     const Relocate_info<32, big_endian>* relinfo,
12256     Output_section* output_section,
12257     unsigned char* view,
12258     Arm_address address,
12259     section_size_type view_size)
12260 {
12261   Relocate relocate;
12262   const Stub_template* stub_template = stub->stub_template();
12263   for (size_t i = 0; i < stub_template->reloc_count(); i++)
12264     {
12265       size_t reloc_insn_index = stub_template->reloc_insn_index(i);
12266       const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
12267
12268       unsigned int r_type = insn->r_type();
12269       section_size_type reloc_offset = stub_template->reloc_offset(i);
12270       section_size_type reloc_size = insn->size();
12271       gold_assert(reloc_offset + reloc_size <= view_size);
12272
12273       // This is the address of the stub destination.
12274       Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
12275       Symbol_value<32> symval;
12276       symval.set_output_value(target);
12277
12278       // Synthesize a fake reloc just in case.  We don't have a symbol so
12279       // we use 0.
12280       unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
12281       memset(reloc_buffer, 0, sizeof(reloc_buffer));
12282       elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
12283       reloc_write.put_r_offset(reloc_offset);
12284       reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
12285       elfcpp::Rel<32, big_endian> rel(reloc_buffer);
12286
12287       relocate.relocate(relinfo, this, output_section,
12288                         this->fake_relnum_for_stubs, rel, r_type,
12289                         NULL, &symval, view + reloc_offset,
12290                         address + reloc_offset, reloc_size);
12291     }
12292 }
12293
12294 // Determine whether an object attribute tag takes an integer, a
12295 // string or both.
12296
12297 template<bool big_endian>
12298 int
12299 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
12300 {
12301   if (tag == Object_attribute::Tag_compatibility)
12302     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
12303             | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
12304   else if (tag == elfcpp::Tag_nodefaults)
12305     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
12306             | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
12307   else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
12308     return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
12309   else if (tag < 32)
12310     return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
12311   else
12312     return ((tag & 1) != 0
12313             ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
12314             : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
12315 }
12316
12317 // Reorder attributes.
12318 //
12319 // The ABI defines that Tag_conformance should be emitted first, and that
12320 // Tag_nodefaults should be second (if either is defined).  This sets those
12321 // two positions, and bumps up the position of all the remaining tags to
12322 // compensate.
12323
12324 template<bool big_endian>
12325 int
12326 Target_arm<big_endian>::do_attributes_order(int num) const
12327 {
12328   // Reorder the known object attributes in output.  We want to move
12329   // Tag_conformance to position 4 and Tag_conformance to position 5
12330   // and shift everything between 4 .. Tag_conformance - 1 to make room.
12331   if (num == 4)
12332     return elfcpp::Tag_conformance;
12333   if (num == 5)
12334     return elfcpp::Tag_nodefaults;
12335   if ((num - 2) < elfcpp::Tag_nodefaults)
12336     return num - 2;
12337   if ((num - 1) < elfcpp::Tag_conformance)
12338     return num - 1;
12339   return num;
12340 }
12341
12342 // Scan a span of THUMB code for Cortex-A8 erratum.
12343
12344 template<bool big_endian>
12345 void
12346 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
12347     Arm_relobj<big_endian>* arm_relobj,
12348     unsigned int shndx,
12349     section_size_type span_start,
12350     section_size_type span_end,
12351     const unsigned char* view,
12352     Arm_address address)
12353 {
12354   // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
12355   //
12356   // The opcode is BLX.W, BL.W, B.W, Bcc.W
12357   // The branch target is in the same 4KB region as the
12358   // first half of the branch.
12359   // The instruction before the branch is a 32-bit
12360   // length non-branch instruction.
12361   section_size_type i = span_start;
12362   bool last_was_32bit = false;
12363   bool last_was_branch = false;
12364   while (i < span_end)
12365     {
12366       typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
12367       const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
12368       uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
12369       bool is_blx = false, is_b = false;
12370       bool is_bl = false, is_bcc = false;
12371
12372       bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
12373       if (insn_32bit)
12374         {
12375           // Load the rest of the insn (in manual-friendly order).
12376           insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
12377
12378           // Encoding T4: B<c>.W.
12379           is_b = (insn & 0xf800d000U) == 0xf0009000U;
12380           // Encoding T1: BL<c>.W.
12381           is_bl = (insn & 0xf800d000U) == 0xf000d000U;
12382           // Encoding T2: BLX<c>.W.
12383           is_blx = (insn & 0xf800d000U) == 0xf000c000U;
12384           // Encoding T3: B<c>.W (not permitted in IT block).
12385           is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
12386                     && (insn & 0x07f00000U) != 0x03800000U);
12387         }
12388
12389       bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
12390
12391       // If this instruction is a 32-bit THUMB branch that crosses a 4K
12392       // page boundary and it follows 32-bit non-branch instruction,
12393       // we need to work around.
12394       if (is_32bit_branch
12395           && ((address + i) & 0xfffU) == 0xffeU
12396           && last_was_32bit
12397           && !last_was_branch)
12398         {
12399           // Check to see if there is a relocation stub for this branch.
12400           bool force_target_arm = false;
12401           bool force_target_thumb = false;
12402           const Cortex_a8_reloc* cortex_a8_reloc = NULL;
12403           Cortex_a8_relocs_info::const_iterator p =
12404             this->cortex_a8_relocs_info_.find(address + i);
12405
12406           if (p != this->cortex_a8_relocs_info_.end())
12407             {
12408               cortex_a8_reloc = p->second;
12409               bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
12410
12411               if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
12412                   && !target_is_thumb)
12413                 force_target_arm = true;
12414               else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
12415                        && target_is_thumb)
12416                 force_target_thumb = true;
12417             }
12418
12419           off_t offset;
12420           Stub_type stub_type = arm_stub_none;
12421
12422           // Check if we have an offending branch instruction.
12423           uint16_t upper_insn = (insn >> 16) & 0xffffU;
12424           uint16_t lower_insn = insn & 0xffffU;
12425           typedef class Arm_relocate_functions<big_endian> RelocFuncs;
12426
12427           if (cortex_a8_reloc != NULL
12428               && cortex_a8_reloc->reloc_stub() != NULL)
12429             // We've already made a stub for this instruction, e.g.
12430             // it's a long branch or a Thumb->ARM stub.  Assume that
12431             // stub will suffice to work around the A8 erratum (see
12432             // setting of always_after_branch above).
12433             ;
12434           else if (is_bcc)
12435             {
12436               offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
12437                                                               lower_insn);
12438               stub_type = arm_stub_a8_veneer_b_cond;
12439             }
12440           else if (is_b || is_bl || is_blx)
12441             {
12442               offset = RelocFuncs::thumb32_branch_offset(upper_insn,
12443                                                          lower_insn);
12444               if (is_blx)
12445                 offset &= ~3;
12446
12447               stub_type = (is_blx
12448                            ? arm_stub_a8_veneer_blx
12449                            : (is_bl
12450                               ? arm_stub_a8_veneer_bl
12451                               : arm_stub_a8_veneer_b));
12452             }
12453
12454           if (stub_type != arm_stub_none)
12455             {
12456               Arm_address pc_for_insn = address + i + 4;
12457
12458               // The original instruction is a BL, but the target is
12459               // an ARM instruction.  If we were not making a stub,
12460               // the BL would have been converted to a BLX.  Use the
12461               // BLX stub instead in that case.
12462               if (this->may_use_v5t_interworking() && force_target_arm
12463                   && stub_type == arm_stub_a8_veneer_bl)
12464                 {
12465                   stub_type = arm_stub_a8_veneer_blx;
12466                   is_blx = true;
12467                   is_bl = false;
12468                 }
12469               // Conversely, if the original instruction was
12470               // BLX but the target is Thumb mode, use the BL stub.
12471               else if (force_target_thumb
12472                        && stub_type == arm_stub_a8_veneer_blx)
12473                 {
12474                   stub_type = arm_stub_a8_veneer_bl;
12475                   is_blx = false;
12476                   is_bl = true;
12477                 }
12478
12479               if (is_blx)
12480                 pc_for_insn &= ~3;
12481
12482               // If we found a relocation, use the proper destination,
12483               // not the offset in the (unrelocated) instruction.
12484               // Note this is always done if we switched the stub type above.
12485               if (cortex_a8_reloc != NULL)
12486                 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
12487
12488               Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
12489
12490               // Add a new stub if destination address in in the same page.
12491               if (((address + i) & ~0xfffU) == (target & ~0xfffU))
12492                 {
12493                   Cortex_a8_stub* stub =
12494                     this->stub_factory_.make_cortex_a8_stub(stub_type,
12495                                                             arm_relobj, shndx,
12496                                                             address + i,
12497                                                             target, insn);
12498                   Stub_table<big_endian>* stub_table =
12499                     arm_relobj->stub_table(shndx);
12500                   gold_assert(stub_table != NULL);
12501                   stub_table->add_cortex_a8_stub(address + i, stub);
12502                 }
12503             }
12504         }
12505
12506       i += insn_32bit ? 4 : 2;
12507       last_was_32bit = insn_32bit;
12508       last_was_branch = is_32bit_branch;
12509     }
12510 }
12511
12512 // Apply the Cortex-A8 workaround.
12513
12514 template<bool big_endian>
12515 void
12516 Target_arm<big_endian>::apply_cortex_a8_workaround(
12517     const Cortex_a8_stub* stub,
12518     Arm_address stub_address,
12519     unsigned char* insn_view,
12520     Arm_address insn_address)
12521 {
12522   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
12523   Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
12524   Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
12525   Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
12526   off_t branch_offset = stub_address - (insn_address + 4);
12527
12528   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
12529   switch (stub->stub_template()->type())
12530     {
12531     case arm_stub_a8_veneer_b_cond:
12532       // For a conditional branch, we re-write it to be an unconditional
12533       // branch to the stub.  We use the THUMB-2 encoding here.
12534       upper_insn = 0xf000U;
12535       lower_insn = 0xb800U;
12536       // Fall through
12537     case arm_stub_a8_veneer_b:
12538     case arm_stub_a8_veneer_bl:
12539     case arm_stub_a8_veneer_blx:
12540       if ((lower_insn & 0x5000U) == 0x4000U)
12541         // For a BLX instruction, make sure that the relocation is
12542         // rounded up to a word boundary.  This follows the semantics of
12543         // the instruction which specifies that bit 1 of the target
12544         // address will come from bit 1 of the base address.
12545         branch_offset = (branch_offset + 2) & ~3;
12546
12547       // Put BRANCH_OFFSET back into the insn.
12548       gold_assert(!Bits<25>::has_overflow32(branch_offset));
12549       upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
12550       lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
12551       break;
12552
12553     default:
12554       gold_unreachable();
12555     }
12556
12557   // Put the relocated value back in the object file:
12558   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
12559   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
12560 }
12561
12562 // Target selector for ARM.  Note this is never instantiated directly.
12563 // It's only used in Target_selector_arm_nacl, below.
12564
12565 template<bool big_endian>
12566 class Target_selector_arm : public Target_selector
12567 {
12568  public:
12569   Target_selector_arm()
12570     : Target_selector(elfcpp::EM_ARM, 32, big_endian,
12571                       (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
12572                       (big_endian ? "armelfb" : "armelf"))
12573   { }
12574
12575   Target*
12576   do_instantiate_target()
12577   { return new Target_arm<big_endian>(); }
12578 };
12579
12580 // Fix .ARM.exidx section coverage.
12581
12582 template<bool big_endian>
12583 void
12584 Target_arm<big_endian>::fix_exidx_coverage(
12585     Layout* layout,
12586     const Input_objects* input_objects,
12587     Arm_output_section<big_endian>* exidx_section,
12588     Symbol_table* symtab,
12589     const Task* task)
12590 {
12591   // We need to look at all the input sections in output in ascending
12592   // order of of output address.  We do that by building a sorted list
12593   // of output sections by addresses.  Then we looks at the output sections
12594   // in order.  The input sections in an output section are already sorted
12595   // by addresses within the output section.
12596
12597   typedef std::set<Output_section*, output_section_address_less_than>
12598       Sorted_output_section_list;
12599   Sorted_output_section_list sorted_output_sections;
12600
12601   // Find out all the output sections of input sections pointed by
12602   // EXIDX input sections.
12603   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
12604        p != input_objects->relobj_end();
12605        ++p)
12606     {
12607       Arm_relobj<big_endian>* arm_relobj =
12608         Arm_relobj<big_endian>::as_arm_relobj(*p);
12609       std::vector<unsigned int> shndx_list;
12610       arm_relobj->get_exidx_shndx_list(&shndx_list);
12611       for (size_t i = 0; i < shndx_list.size(); ++i)
12612         {
12613           const Arm_exidx_input_section* exidx_input_section =
12614             arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
12615           gold_assert(exidx_input_section != NULL);
12616           if (!exidx_input_section->has_errors())
12617             {
12618               unsigned int text_shndx = exidx_input_section->link();
12619               Output_section* os = arm_relobj->output_section(text_shndx);
12620               if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
12621                 sorted_output_sections.insert(os);
12622             }
12623         }
12624     }
12625
12626   // Go over the output sections in ascending order of output addresses.
12627   typedef typename Arm_output_section<big_endian>::Text_section_list
12628       Text_section_list;
12629   Text_section_list sorted_text_sections;
12630   for (typename Sorted_output_section_list::iterator p =
12631         sorted_output_sections.begin();
12632       p != sorted_output_sections.end();
12633       ++p)
12634     {
12635       Arm_output_section<big_endian>* arm_output_section =
12636         Arm_output_section<big_endian>::as_arm_output_section(*p);
12637       arm_output_section->append_text_sections_to_list(&sorted_text_sections);
12638     }
12639
12640   exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
12641                                     merge_exidx_entries(), task);
12642 }
12643
12644 template<bool big_endian>
12645 void
12646 Target_arm<big_endian>::do_define_standard_symbols(
12647     Symbol_table* symtab,
12648     Layout* layout)
12649 {
12650   // Handle the .ARM.exidx section.
12651   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
12652
12653   if (exidx_section != NULL)
12654     {
12655       // Create __exidx_start and __exidx_end symbols.
12656       symtab->define_in_output_data("__exidx_start",
12657                                     NULL, // version
12658                                     Symbol_table::PREDEFINED,
12659                                     exidx_section,
12660                                     0, // value
12661                                     0, // symsize
12662                                     elfcpp::STT_NOTYPE,
12663                                     elfcpp::STB_GLOBAL,
12664                                     elfcpp::STV_HIDDEN,
12665                                     0, // nonvis
12666                                     false, // offset_is_from_end
12667                                     true); // only_if_ref
12668
12669       symtab->define_in_output_data("__exidx_end",
12670                                     NULL, // version
12671                                     Symbol_table::PREDEFINED,
12672                                     exidx_section,
12673                                     0, // value
12674                                     0, // symsize
12675                                     elfcpp::STT_NOTYPE,
12676                                     elfcpp::STB_GLOBAL,
12677                                     elfcpp::STV_HIDDEN,
12678                                     0, // nonvis
12679                                     true, // offset_is_from_end
12680                                     true); // only_if_ref
12681     }
12682   else
12683     {
12684       // Define __exidx_start and __exidx_end even when .ARM.exidx
12685       // section is missing to match ld's behaviour.
12686       symtab->define_as_constant("__exidx_start", NULL,
12687                                  Symbol_table::PREDEFINED,
12688                                  0, 0, elfcpp::STT_OBJECT,
12689                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12690                                  true, false);
12691       symtab->define_as_constant("__exidx_end", NULL,
12692                                  Symbol_table::PREDEFINED,
12693                                  0, 0, elfcpp::STT_OBJECT,
12694                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12695                                  true, false);
12696     }
12697 }
12698
12699 // NaCl variant.  It uses different PLT contents.
12700
12701 template<bool big_endian>
12702 class Output_data_plt_arm_nacl;
12703
12704 template<bool big_endian>
12705 class Target_arm_nacl : public Target_arm<big_endian>
12706 {
12707  public:
12708   Target_arm_nacl()
12709     : Target_arm<big_endian>(&arm_nacl_info)
12710   { }
12711
12712  protected:
12713   virtual Output_data_plt_arm<big_endian>*
12714   do_make_data_plt(
12715                    Layout* layout,
12716                    Arm_output_data_got<big_endian>* got,
12717                    Output_data_space* got_plt,
12718                    Output_data_space* got_irelative)
12719   { return new Output_data_plt_arm_nacl<big_endian>(
12720       layout, got, got_plt, got_irelative); }
12721
12722  private:
12723   static const Target::Target_info arm_nacl_info;
12724 };
12725
12726 template<bool big_endian>
12727 const Target::Target_info Target_arm_nacl<big_endian>::arm_nacl_info =
12728 {
12729   32,                   // size
12730   big_endian,           // is_big_endian
12731   elfcpp::EM_ARM,       // machine_code
12732   false,                // has_make_symbol
12733   false,                // has_resolve
12734   false,                // has_code_fill
12735   true,                 // is_default_stack_executable
12736   false,                // can_icf_inline_merge_sections
12737   '\0',                 // wrap_char
12738   "/lib/ld-nacl-arm.so.1", // dynamic_linker
12739   0x20000,              // default_text_segment_address
12740   0x10000,              // abi_pagesize (overridable by -z max-page-size)
12741   0x10000,              // common_pagesize (overridable by -z common-page-size)
12742   true,                 // isolate_execinstr
12743   0x10000000,           // rosegment_gap
12744   elfcpp::SHN_UNDEF,    // small_common_shndx
12745   elfcpp::SHN_UNDEF,    // large_common_shndx
12746   0,                    // small_common_section_flags
12747   0,                    // large_common_section_flags
12748   ".ARM.attributes",    // attributes_section
12749   "aeabi",              // attributes_vendor
12750   "_start",             // entry_symbol_name
12751   32,                   // hash_entry_size
12752 };
12753
12754 template<bool big_endian>
12755 class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
12756 {
12757  public:
12758   Output_data_plt_arm_nacl(
12759       Layout* layout,
12760       Arm_output_data_got<big_endian>* got,
12761       Output_data_space* got_plt,
12762       Output_data_space* got_irelative)
12763     : Output_data_plt_arm<big_endian>(layout, 16, got, got_plt, got_irelative)
12764   { }
12765
12766  protected:
12767   // Return the offset of the first non-reserved PLT entry.
12768   virtual unsigned int
12769   do_first_plt_entry_offset() const
12770   { return sizeof(first_plt_entry); }
12771
12772   // Return the size of a PLT entry.
12773   virtual unsigned int
12774   do_get_plt_entry_size() const
12775   { return sizeof(plt_entry); }
12776
12777   virtual void
12778   do_fill_first_plt_entry(unsigned char* pov,
12779                           Arm_address got_address,
12780                           Arm_address plt_address);
12781
12782   virtual void
12783   do_fill_plt_entry(unsigned char* pov,
12784                     Arm_address got_address,
12785                     Arm_address plt_address,
12786                     unsigned int got_offset,
12787                     unsigned int plt_offset);
12788
12789  private:
12790   inline uint32_t arm_movw_immediate(uint32_t value)
12791   {
12792     return (value & 0x00000fff) | ((value & 0x0000f000) << 4);
12793   }
12794
12795   inline uint32_t arm_movt_immediate(uint32_t value)
12796   {
12797     return ((value & 0x0fff0000) >> 16) | ((value & 0xf0000000) >> 12);
12798   }
12799
12800   // Template for the first PLT entry.
12801   static const uint32_t first_plt_entry[16];
12802
12803   // Template for subsequent PLT entries.
12804   static const uint32_t plt_entry[4];
12805 };
12806
12807 // The first entry in the PLT.
12808 template<bool big_endian>
12809 const uint32_t Output_data_plt_arm_nacl<big_endian>::first_plt_entry[16] =
12810 {
12811   // First bundle:
12812   0xe300c000,                           // movw ip, #:lower16:&GOT[2]-.+8
12813   0xe340c000,                           // movt ip, #:upper16:&GOT[2]-.+8
12814   0xe08cc00f,                           // add  ip, ip, pc
12815   0xe52dc008,                           // str  ip, [sp, #-8]!
12816   // Second bundle:
12817   0xe3ccc103,                           // bic  ip, ip, #0xc0000000
12818   0xe59cc000,                           // ldr  ip, [ip]
12819   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
12820   0xe12fff1c,                           // bx   ip
12821   // Third bundle:
12822   0xe320f000,                           // nop
12823   0xe320f000,                           // nop
12824   0xe320f000,                           // nop
12825   // .Lplt_tail:
12826   0xe50dc004,                           // str  ip, [sp, #-4]
12827   // Fourth bundle:
12828   0xe3ccc103,                           // bic  ip, ip, #0xc0000000
12829   0xe59cc000,                           // ldr  ip, [ip]
12830   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
12831   0xe12fff1c,                           // bx   ip
12832 };
12833
12834 template<bool big_endian>
12835 void
12836 Output_data_plt_arm_nacl<big_endian>::do_fill_first_plt_entry(
12837     unsigned char* pov,
12838     Arm_address got_address,
12839     Arm_address plt_address)
12840 {
12841   // Write first PLT entry.  All but first two words are constants.
12842   const size_t num_first_plt_words = (sizeof(first_plt_entry)
12843                                       / sizeof(first_plt_entry[0]));
12844
12845   int32_t got_displacement = got_address + 8 - (plt_address + 16);
12846
12847   elfcpp::Swap<32, big_endian>::writeval
12848     (pov + 0, first_plt_entry[0] | arm_movw_immediate (got_displacement));
12849   elfcpp::Swap<32, big_endian>::writeval
12850     (pov + 4, first_plt_entry[1] | arm_movt_immediate (got_displacement));
12851
12852   for (size_t i = 2; i < num_first_plt_words; ++i)
12853     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
12854 }
12855
12856 // Subsequent entries in the PLT.
12857
12858 template<bool big_endian>
12859 const uint32_t Output_data_plt_arm_nacl<big_endian>::plt_entry[4] =
12860 {
12861   0xe300c000,                           // movw ip, #:lower16:&GOT[n]-.+8
12862   0xe340c000,                           // movt ip, #:upper16:&GOT[n]-.+8
12863   0xe08cc00f,                           // add  ip, ip, pc
12864   0xea000000,                           // b    .Lplt_tail
12865 };
12866
12867 template<bool big_endian>
12868 void
12869 Output_data_plt_arm_nacl<big_endian>::do_fill_plt_entry(
12870     unsigned char* pov,
12871     Arm_address got_address,
12872     Arm_address plt_address,
12873     unsigned int got_offset,
12874     unsigned int plt_offset)
12875 {
12876   // Calculate the displacement between the PLT slot and the
12877   // common tail that's part of the special initial PLT slot.
12878   int32_t tail_displacement = (plt_address + (11 * sizeof(uint32_t))
12879                                - (plt_address + plt_offset
12880                                   + sizeof(plt_entry) + sizeof(uint32_t)));
12881   gold_assert((tail_displacement & 3) == 0);
12882   tail_displacement >>= 2;
12883
12884   gold_assert ((tail_displacement & 0xff000000) == 0
12885                || (-tail_displacement & 0xff000000) == 0);
12886
12887   // Calculate the displacement between the PLT slot and the entry
12888   // in the GOT.  The offset accounts for the value produced by
12889   // adding to pc in the penultimate instruction of the PLT stub.
12890   const int32_t got_displacement = (got_address + got_offset
12891                                     - (plt_address + sizeof(plt_entry)));
12892
12893   elfcpp::Swap<32, big_endian>::writeval
12894     (pov + 0, plt_entry[0] | arm_movw_immediate (got_displacement));
12895   elfcpp::Swap<32, big_endian>::writeval
12896     (pov + 4, plt_entry[1] | arm_movt_immediate (got_displacement));
12897   elfcpp::Swap<32, big_endian>::writeval
12898     (pov + 8, plt_entry[2]);
12899   elfcpp::Swap<32, big_endian>::writeval
12900     (pov + 12, plt_entry[3] | (tail_displacement & 0x00ffffff));
12901 }
12902
12903 // Target selectors.
12904
12905 template<bool big_endian>
12906 class Target_selector_arm_nacl
12907   : public Target_selector_nacl<Target_selector_arm<big_endian>,
12908                                 Target_arm_nacl<big_endian> >
12909 {
12910  public:
12911   Target_selector_arm_nacl()
12912     : Target_selector_nacl<Target_selector_arm<big_endian>,
12913                            Target_arm_nacl<big_endian> >(
12914           "arm",
12915           big_endian ? "elf32-bigarm-nacl" : "elf32-littlearm-nacl",
12916           big_endian ? "armelfb_nacl" : "armelf_nacl")
12917   { }
12918 };
12919
12920 Target_selector_arm_nacl<false> target_selector_arm;
12921 Target_selector_arm_nacl<true> target_selector_armbe;
12922
12923 } // End anonymous namespace.