* powerpc.cc (Target_selector_powerpc::Target_selector_powerpc):
[platform/upstream/binutils.git] / gold / arm.cc
1 // arm.cc -- arm target support for gold.
2
3 // Copyright 2009, 2010, 2011, 2012 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), rel_dyn_(NULL),
2123       copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL),
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   // Relocate a section.
2262   void
2263   relocate_section(const Relocate_info<32, big_endian>*,
2264                    unsigned int sh_type,
2265                    const unsigned char* prelocs,
2266                    size_t reloc_count,
2267                    Output_section* output_section,
2268                    bool needs_special_offset_handling,
2269                    unsigned char* view,
2270                    Arm_address view_address,
2271                    section_size_type view_size,
2272                    const Reloc_symbol_changes*);
2273
2274   // Scan the relocs during a relocatable link.
2275   void
2276   scan_relocatable_relocs(Symbol_table* symtab,
2277                           Layout* layout,
2278                           Sized_relobj_file<32, big_endian>* object,
2279                           unsigned int data_shndx,
2280                           unsigned int sh_type,
2281                           const unsigned char* prelocs,
2282                           size_t reloc_count,
2283                           Output_section* output_section,
2284                           bool needs_special_offset_handling,
2285                           size_t local_symbol_count,
2286                           const unsigned char* plocal_symbols,
2287                           Relocatable_relocs*);
2288
2289   // Emit relocations for a section.
2290   void
2291   relocate_relocs(const Relocate_info<32, big_endian>*,
2292                   unsigned int sh_type,
2293                   const unsigned char* prelocs,
2294                   size_t reloc_count,
2295                   Output_section* output_section,
2296                   typename elfcpp::Elf_types<32>::Elf_Off
2297                     offset_in_output_section,
2298                   const Relocatable_relocs*,
2299                   unsigned char* view,
2300                   Arm_address view_address,
2301                   section_size_type view_size,
2302                   unsigned char* reloc_view,
2303                   section_size_type reloc_view_size);
2304
2305   // Perform target-specific processing in a relocatable link.  This is
2306   // only used if we use the relocation strategy RELOC_SPECIAL.
2307   void
2308   relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2309                                unsigned int sh_type,
2310                                const unsigned char* preloc_in,
2311                                size_t relnum,
2312                                Output_section* output_section,
2313                                typename elfcpp::Elf_types<32>::Elf_Off
2314                                  offset_in_output_section,
2315                                unsigned char* view,
2316                                typename elfcpp::Elf_types<32>::Elf_Addr
2317                                  view_address,
2318                                section_size_type view_size,
2319                                unsigned char* preloc_out);
2320
2321   // Return whether SYM is defined by the ABI.
2322   bool
2323   do_is_defined_by_abi(const Symbol* sym) const
2324   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2325
2326   // Return whether there is a GOT section.
2327   bool
2328   has_got_section() const
2329   { return this->got_ != NULL; }
2330
2331   // Return the size of the GOT section.
2332   section_size_type
2333   got_size() const
2334   {
2335     gold_assert(this->got_ != NULL);
2336     return this->got_->data_size();
2337   }
2338
2339   // Return the number of entries in the GOT.
2340   unsigned int
2341   got_entry_count() const
2342   {
2343     if (!this->has_got_section())
2344       return 0;
2345     return this->got_size() / 4;
2346   }
2347
2348   // Return the number of entries in the PLT.
2349   unsigned int
2350   plt_entry_count() const;
2351
2352   // Return the offset of the first non-reserved PLT entry.
2353   unsigned int
2354   first_plt_entry_offset() const;
2355
2356   // Return the size of each PLT entry.
2357   unsigned int
2358   plt_entry_size() const;
2359
2360   // Map platform-specific reloc types
2361   static unsigned int
2362   get_real_reloc_type(unsigned int r_type);
2363
2364   //
2365   // Methods to support stub-generations.
2366   //
2367
2368   // Return the stub factory
2369   const Stub_factory&
2370   stub_factory() const
2371   { return this->stub_factory_; }
2372
2373   // Make a new Arm_input_section object.
2374   Arm_input_section<big_endian>*
2375   new_arm_input_section(Relobj*, unsigned int);
2376
2377   // Find the Arm_input_section object corresponding to the SHNDX-th input
2378   // section of RELOBJ.
2379   Arm_input_section<big_endian>*
2380   find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2381
2382   // Make a new Stub_table
2383   Stub_table<big_endian>*
2384   new_stub_table(Arm_input_section<big_endian>*);
2385
2386   // Scan a section for stub generation.
2387   void
2388   scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2389                          const unsigned char*, size_t, Output_section*,
2390                          bool, const unsigned char*, Arm_address,
2391                          section_size_type);
2392
2393   // Relocate a stub.
2394   void
2395   relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2396                 Output_section*, unsigned char*, Arm_address,
2397                 section_size_type);
2398
2399   // Get the default ARM target.
2400   static Target_arm<big_endian>*
2401   default_target()
2402   {
2403     gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2404                 && parameters->target().is_big_endian() == big_endian);
2405     return static_cast<Target_arm<big_endian>*>(
2406              parameters->sized_target<32, big_endian>());
2407   }
2408
2409   // Whether NAME belongs to a mapping symbol.
2410   static bool
2411   is_mapping_symbol_name(const char* name)
2412   {
2413     return (name
2414             && name[0] == '$'
2415             && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2416             && (name[2] == '\0' || name[2] == '.'));
2417   }
2418
2419   // Whether we work around the Cortex-A8 erratum.
2420   bool
2421   fix_cortex_a8() const
2422   { return this->fix_cortex_a8_; }
2423
2424   // Whether we merge exidx entries in debuginfo.
2425   bool
2426   merge_exidx_entries() const
2427   { return parameters->options().merge_exidx_entries(); }
2428
2429   // Whether we fix R_ARM_V4BX relocation.
2430   // 0 - do not fix
2431   // 1 - replace with MOV instruction (armv4 target)
2432   // 2 - make interworking veneer (>= armv4t targets only)
2433   General_options::Fix_v4bx
2434   fix_v4bx() const
2435   { return parameters->options().fix_v4bx(); }
2436
2437   // Scan a span of THUMB code section for Cortex-A8 erratum.
2438   void
2439   scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2440                                   section_size_type, section_size_type,
2441                                   const unsigned char*, Arm_address);
2442
2443   // Apply Cortex-A8 workaround to a branch.
2444   void
2445   apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2446                              unsigned char*, Arm_address);
2447
2448  protected:
2449   // Make the PLT-generator object.
2450   Output_data_plt_arm<big_endian>*
2451   make_data_plt(Layout* layout, Output_data_space* got_plt)
2452   { return this->do_make_data_plt(layout, got_plt); }
2453
2454   // Make an ELF object.
2455   Object*
2456   do_make_elf_object(const std::string&, Input_file*, off_t,
2457                      const elfcpp::Ehdr<32, big_endian>& ehdr);
2458
2459   Object*
2460   do_make_elf_object(const std::string&, Input_file*, off_t,
2461                      const elfcpp::Ehdr<32, !big_endian>&)
2462   { gold_unreachable(); }
2463
2464   Object*
2465   do_make_elf_object(const std::string&, Input_file*, off_t,
2466                       const elfcpp::Ehdr<64, false>&)
2467   { gold_unreachable(); }
2468
2469   Object*
2470   do_make_elf_object(const std::string&, Input_file*, off_t,
2471                      const elfcpp::Ehdr<64, true>&)
2472   { gold_unreachable(); }
2473
2474   // Make an output section.
2475   Output_section*
2476   do_make_output_section(const char* name, elfcpp::Elf_Word type,
2477                          elfcpp::Elf_Xword flags)
2478   { return new Arm_output_section<big_endian>(name, type, flags); }
2479
2480   void
2481   do_adjust_elf_header(unsigned char* view, int len);
2482
2483   // We only need to generate stubs, and hence perform relaxation if we are
2484   // not doing relocatable linking.
2485   bool
2486   do_may_relax() const
2487   { return !parameters->options().relocatable(); }
2488
2489   bool
2490   do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
2491
2492   // Determine whether an object attribute tag takes an integer, a
2493   // string or both.
2494   int
2495   do_attribute_arg_type(int tag) const;
2496
2497   // Reorder tags during output.
2498   int
2499   do_attributes_order(int num) const;
2500
2501   // This is called when the target is selected as the default.
2502   void
2503   do_select_as_default_target()
2504   {
2505     // No locking is required since there should only be one default target.
2506     // We cannot have both the big-endian and little-endian ARM targets
2507     // as the default.
2508     gold_assert(arm_reloc_property_table == NULL);
2509     arm_reloc_property_table = new Arm_reloc_property_table();
2510   }
2511
2512   // Virtual function which is set to return true by a target if
2513   // it can use relocation types to determine if a function's
2514   // pointer is taken.
2515   virtual bool
2516   do_can_check_for_function_pointers() const
2517   { return true; }
2518
2519   // Whether a section called SECTION_NAME may have function pointers to
2520   // sections not eligible for safe ICF folding.
2521   virtual bool
2522   do_section_may_have_icf_unsafe_pointers(const char* section_name) const
2523   {
2524     return (!is_prefix_of(".ARM.exidx", section_name)
2525             && !is_prefix_of(".ARM.extab", section_name)
2526             && Target::do_section_may_have_icf_unsafe_pointers(section_name));
2527   }
2528
2529   virtual void
2530   do_define_standard_symbols(Symbol_table*, Layout*);
2531
2532   virtual Output_data_plt_arm<big_endian>*
2533   do_make_data_plt(Layout* layout, Output_data_space* got_plt)
2534   {
2535     return new Output_data_plt_arm_standard<big_endian>(layout, got_plt);
2536   }
2537
2538  private:
2539   // The class which scans relocations.
2540   class Scan
2541   {
2542    public:
2543     Scan()
2544       : issued_non_pic_error_(false)
2545     { }
2546
2547     static inline int
2548     get_reference_flags(unsigned int r_type);
2549
2550     inline void
2551     local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2552           Sized_relobj_file<32, big_endian>* object,
2553           unsigned int data_shndx,
2554           Output_section* output_section,
2555           const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2556           const elfcpp::Sym<32, big_endian>& lsym,
2557           bool is_discarded);
2558
2559     inline void
2560     global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2561            Sized_relobj_file<32, big_endian>* object,
2562            unsigned int data_shndx,
2563            Output_section* output_section,
2564            const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2565            Symbol* gsym);
2566
2567     inline bool
2568     local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2569                                         Sized_relobj_file<32, big_endian>* ,
2570                                         unsigned int ,
2571                                         Output_section* ,
2572                                         const elfcpp::Rel<32, big_endian>& ,
2573                                         unsigned int ,
2574                                         const elfcpp::Sym<32, big_endian>&);
2575
2576     inline bool
2577     global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2578                                          Sized_relobj_file<32, big_endian>* ,
2579                                          unsigned int ,
2580                                          Output_section* ,
2581                                          const elfcpp::Rel<32, big_endian>& ,
2582                                          unsigned int , Symbol*);
2583
2584    private:
2585     static void
2586     unsupported_reloc_local(Sized_relobj_file<32, big_endian>*,
2587                             unsigned int r_type);
2588
2589     static void
2590     unsupported_reloc_global(Sized_relobj_file<32, big_endian>*,
2591                              unsigned int r_type, Symbol*);
2592
2593     void
2594     check_non_pic(Relobj*, unsigned int r_type);
2595
2596     // Almost identical to Symbol::needs_plt_entry except that it also
2597     // handles STT_ARM_TFUNC.
2598     static bool
2599     symbol_needs_plt_entry(const Symbol* sym)
2600     {
2601       // An undefined symbol from an executable does not need a PLT entry.
2602       if (sym->is_undefined() && !parameters->options().shared())
2603         return false;
2604
2605       return (!parameters->doing_static_link()
2606               && (sym->type() == elfcpp::STT_FUNC
2607                   || sym->type() == elfcpp::STT_ARM_TFUNC)
2608               && (sym->is_from_dynobj()
2609                   || sym->is_undefined()
2610                   || sym->is_preemptible()));
2611     }
2612
2613     inline bool
2614     possible_function_pointer_reloc(unsigned int r_type);
2615
2616     // Whether we have issued an error about a non-PIC compilation.
2617     bool issued_non_pic_error_;
2618   };
2619
2620   // The class which implements relocation.
2621   class Relocate
2622   {
2623    public:
2624     Relocate()
2625     { }
2626
2627     ~Relocate()
2628     { }
2629
2630     // Return whether the static relocation needs to be applied.
2631     inline bool
2632     should_apply_static_reloc(const Sized_symbol<32>* gsym,
2633                               unsigned int r_type,
2634                               bool is_32bit,
2635                               Output_section* output_section);
2636
2637     // Do a relocation.  Return false if the caller should not issue
2638     // any warnings about this relocation.
2639     inline bool
2640     relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2641              Output_section*,  size_t relnum,
2642              const elfcpp::Rel<32, big_endian>&,
2643              unsigned int r_type, const Sized_symbol<32>*,
2644              const Symbol_value<32>*,
2645              unsigned char*, Arm_address,
2646              section_size_type);
2647
2648     // Return whether we want to pass flag NON_PIC_REF for this
2649     // reloc.  This means the relocation type accesses a symbol not via
2650     // GOT or PLT.
2651     static inline bool
2652     reloc_is_non_pic(unsigned int r_type)
2653     {
2654       switch (r_type)
2655         {
2656         // These relocation types reference GOT or PLT entries explicitly.
2657         case elfcpp::R_ARM_GOT_BREL:
2658         case elfcpp::R_ARM_GOT_ABS:
2659         case elfcpp::R_ARM_GOT_PREL:
2660         case elfcpp::R_ARM_GOT_BREL12:
2661         case elfcpp::R_ARM_PLT32_ABS:
2662         case elfcpp::R_ARM_TLS_GD32:
2663         case elfcpp::R_ARM_TLS_LDM32:
2664         case elfcpp::R_ARM_TLS_IE32:
2665         case elfcpp::R_ARM_TLS_IE12GP:
2666
2667         // These relocate types may use PLT entries.
2668         case elfcpp::R_ARM_CALL:
2669         case elfcpp::R_ARM_THM_CALL:
2670         case elfcpp::R_ARM_JUMP24:
2671         case elfcpp::R_ARM_THM_JUMP24:
2672         case elfcpp::R_ARM_THM_JUMP19:
2673         case elfcpp::R_ARM_PLT32:
2674         case elfcpp::R_ARM_THM_XPC22:
2675         case elfcpp::R_ARM_PREL31:
2676         case elfcpp::R_ARM_SBREL31:
2677           return false;
2678
2679         default:
2680           return true;
2681         }
2682     }
2683
2684    private:
2685     // Do a TLS relocation.
2686     inline typename Arm_relocate_functions<big_endian>::Status
2687     relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2688                  size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2689                  const Sized_symbol<32>*, const Symbol_value<32>*,
2690                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2691                  section_size_type);
2692
2693   };
2694
2695   // A class which returns the size required for a relocation type,
2696   // used while scanning relocs during a relocatable link.
2697   class Relocatable_size_for_reloc
2698   {
2699    public:
2700     unsigned int
2701     get_size_for_reloc(unsigned int, Relobj*);
2702   };
2703
2704   // Adjust TLS relocation type based on the options and whether this
2705   // is a local symbol.
2706   static tls::Tls_optimization
2707   optimize_tls_reloc(bool is_final, int r_type);
2708
2709   // Get the GOT section, creating it if necessary.
2710   Arm_output_data_got<big_endian>*
2711   got_section(Symbol_table*, Layout*);
2712
2713   // Get the GOT PLT section.
2714   Output_data_space*
2715   got_plt_section() const
2716   {
2717     gold_assert(this->got_plt_ != NULL);
2718     return this->got_plt_;
2719   }
2720
2721   // Create a PLT entry for a global symbol.
2722   void
2723   make_plt_entry(Symbol_table*, Layout*, Symbol*);
2724
2725   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2726   void
2727   define_tls_base_symbol(Symbol_table*, Layout*);
2728
2729   // Create a GOT entry for the TLS module index.
2730   unsigned int
2731   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2732                       Sized_relobj_file<32, big_endian>* object);
2733
2734   // Get the PLT section.
2735   const Output_data_plt_arm<big_endian>*
2736   plt_section() const
2737   {
2738     gold_assert(this->plt_ != NULL);
2739     return this->plt_;
2740   }
2741
2742   // Get the dynamic reloc section, creating it if necessary.
2743   Reloc_section*
2744   rel_dyn_section(Layout*);
2745
2746   // Get the section to use for TLS_DESC relocations.
2747   Reloc_section*
2748   rel_tls_desc_section(Layout*) const;
2749
2750   // Return true if the symbol may need a COPY relocation.
2751   // References from an executable object to non-function symbols
2752   // defined in a dynamic object may need a COPY relocation.
2753   bool
2754   may_need_copy_reloc(Symbol* gsym)
2755   {
2756     return (gsym->type() != elfcpp::STT_ARM_TFUNC
2757             && gsym->may_need_copy_reloc());
2758   }
2759
2760   // Add a potential copy relocation.
2761   void
2762   copy_reloc(Symbol_table* symtab, Layout* layout,
2763              Sized_relobj_file<32, big_endian>* object,
2764              unsigned int shndx, Output_section* output_section,
2765              Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2766   {
2767     this->copy_relocs_.copy_reloc(symtab, layout,
2768                                   symtab->get_sized_symbol<32>(sym),
2769                                   object, shndx, output_section, reloc,
2770                                   this->rel_dyn_section(layout));
2771   }
2772
2773   // Whether two EABI versions are compatible.
2774   static bool
2775   are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2776
2777   // Merge processor-specific flags from input object and those in the ELF
2778   // header of the output.
2779   void
2780   merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2781
2782   // Get the secondary compatible architecture.
2783   static int
2784   get_secondary_compatible_arch(const Attributes_section_data*);
2785
2786   // Set the secondary compatible architecture.
2787   static void
2788   set_secondary_compatible_arch(Attributes_section_data*, int);
2789
2790   static int
2791   tag_cpu_arch_combine(const char*, int, int*, int, int);
2792
2793   // Helper to print AEABI enum tag value.
2794   static std::string
2795   aeabi_enum_name(unsigned int);
2796
2797   // Return string value for TAG_CPU_name.
2798   static std::string
2799   tag_cpu_name_value(unsigned int);
2800
2801   // Merge object attributes from input object and those in the output.
2802   void
2803   merge_object_attributes(const char*, const Attributes_section_data*);
2804
2805   // Helper to get an AEABI object attribute
2806   Object_attribute*
2807   get_aeabi_object_attribute(int tag) const
2808   {
2809     Attributes_section_data* pasd = this->attributes_section_data_;
2810     gold_assert(pasd != NULL);
2811     Object_attribute* attr =
2812       pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2813     gold_assert(attr != NULL);
2814     return attr;
2815   }
2816
2817   //
2818   // Methods to support stub-generations.
2819   //
2820
2821   // Group input sections for stub generation.
2822   void
2823   group_sections(Layout*, section_size_type, bool, const Task*);
2824
2825   // Scan a relocation for stub generation.
2826   void
2827   scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2828                       const Sized_symbol<32>*, unsigned int,
2829                       const Symbol_value<32>*,
2830                       elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2831
2832   // Scan a relocation section for stub.
2833   template<int sh_type>
2834   void
2835   scan_reloc_section_for_stubs(
2836       const Relocate_info<32, big_endian>* relinfo,
2837       const unsigned char* prelocs,
2838       size_t reloc_count,
2839       Output_section* output_section,
2840       bool needs_special_offset_handling,
2841       const unsigned char* view,
2842       elfcpp::Elf_types<32>::Elf_Addr view_address,
2843       section_size_type);
2844
2845   // Fix .ARM.exidx section coverage.
2846   void
2847   fix_exidx_coverage(Layout*, const Input_objects*,
2848                      Arm_output_section<big_endian>*, Symbol_table*,
2849                      const Task*);
2850
2851   // Functors for STL set.
2852   struct output_section_address_less_than
2853   {
2854     bool
2855     operator()(const Output_section* s1, const Output_section* s2) const
2856     { return s1->address() < s2->address(); }
2857   };
2858
2859   // Information about this specific target which we pass to the
2860   // general Target structure.
2861   static const Target::Target_info arm_info;
2862
2863   // The types of GOT entries needed for this platform.
2864   // These values are exposed to the ABI in an incremental link.
2865   // Do not renumber existing values without changing the version
2866   // number of the .gnu_incremental_inputs section.
2867   enum Got_type
2868   {
2869     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
2870     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
2871     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
2872     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
2873     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
2874   };
2875
2876   typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2877
2878   // Map input section to Arm_input_section.
2879   typedef Unordered_map<Section_id,
2880                         Arm_input_section<big_endian>*,
2881                         Section_id_hash>
2882           Arm_input_section_map;
2883
2884   // Map output addresses to relocs for Cortex-A8 erratum.
2885   typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2886           Cortex_a8_relocs_info;
2887
2888   // The GOT section.
2889   Arm_output_data_got<big_endian>* got_;
2890   // The PLT section.
2891   Output_data_plt_arm<big_endian>* plt_;
2892   // The GOT PLT section.
2893   Output_data_space* got_plt_;
2894   // The dynamic reloc section.
2895   Reloc_section* rel_dyn_;
2896   // Relocs saved to avoid a COPY reloc.
2897   Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2898   // Space for variables copied with a COPY reloc.
2899   Output_data_space* dynbss_;
2900   // Offset of the GOT entry for the TLS module index.
2901   unsigned int got_mod_index_offset_;
2902   // True if the _TLS_MODULE_BASE_ symbol has been defined.
2903   bool tls_base_symbol_defined_;
2904   // Vector of Stub_tables created.
2905   Stub_table_list stub_tables_;
2906   // Stub factory.
2907   const Stub_factory &stub_factory_;
2908   // Whether we force PIC branch veneers.
2909   bool should_force_pic_veneer_;
2910   // Map for locating Arm_input_sections.
2911   Arm_input_section_map arm_input_section_map_;
2912   // Attributes section data in output.
2913   Attributes_section_data* attributes_section_data_;
2914   // Whether we want to fix code for Cortex-A8 erratum.
2915   bool fix_cortex_a8_;
2916   // Map addresses to relocs for Cortex-A8 erratum.
2917   Cortex_a8_relocs_info cortex_a8_relocs_info_;
2918 };
2919
2920 template<bool big_endian>
2921 const Target::Target_info Target_arm<big_endian>::arm_info =
2922 {
2923   32,                   // size
2924   big_endian,           // is_big_endian
2925   elfcpp::EM_ARM,       // machine_code
2926   false,                // has_make_symbol
2927   false,                // has_resolve
2928   false,                // has_code_fill
2929   true,                 // is_default_stack_executable
2930   false,                // can_icf_inline_merge_sections
2931   '\0',                 // wrap_char
2932   "/usr/lib/libc.so.1", // dynamic_linker
2933   0x8000,               // default_text_segment_address
2934   0x1000,               // abi_pagesize (overridable by -z max-page-size)
2935   0x1000,               // common_pagesize (overridable by -z common-page-size)
2936   false,                // isolate_execinstr
2937   0,                    // rosegment_gap
2938   elfcpp::SHN_UNDEF,    // small_common_shndx
2939   elfcpp::SHN_UNDEF,    // large_common_shndx
2940   0,                    // small_common_section_flags
2941   0,                    // large_common_section_flags
2942   ".ARM.attributes",    // attributes_section
2943   "aeabi"               // attributes_vendor
2944 };
2945
2946 // Arm relocate functions class
2947 //
2948
2949 template<bool big_endian>
2950 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2951 {
2952  public:
2953   typedef enum
2954   {
2955     STATUS_OKAY,        // No error during relocation.
2956     STATUS_OVERFLOW,    // Relocation overflow.
2957     STATUS_BAD_RELOC    // Relocation cannot be applied.
2958   } Status;
2959
2960  private:
2961   typedef Relocate_functions<32, big_endian> Base;
2962   typedef Arm_relocate_functions<big_endian> This;
2963
2964   // Encoding of imm16 argument for movt and movw ARM instructions
2965   // from ARM ARM:
2966   //
2967   //     imm16 := imm4 | imm12
2968   //
2969   //  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
2970   // +-------+---------------+-------+-------+-----------------------+
2971   // |       |               |imm4   |       |imm12                  |
2972   // +-------+---------------+-------+-------+-----------------------+
2973
2974   // Extract the relocation addend from VAL based on the ARM
2975   // instruction encoding described above.
2976   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2977   extract_arm_movw_movt_addend(
2978       typename elfcpp::Swap<32, big_endian>::Valtype val)
2979   {
2980     // According to the Elf ABI for ARM Architecture the immediate
2981     // field is sign-extended to form the addend.
2982     return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff));
2983   }
2984
2985   // Insert X into VAL based on the ARM instruction encoding described
2986   // above.
2987   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2988   insert_val_arm_movw_movt(
2989       typename elfcpp::Swap<32, big_endian>::Valtype val,
2990       typename elfcpp::Swap<32, big_endian>::Valtype x)
2991   {
2992     val &= 0xfff0f000;
2993     val |= x & 0x0fff;
2994     val |= (x & 0xf000) << 4;
2995     return val;
2996   }
2997
2998   // Encoding of imm16 argument for movt and movw Thumb2 instructions
2999   // from ARM ARM:
3000   //
3001   //     imm16 := imm4 | i | imm3 | imm8
3002   //
3003   //  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
3004   // +---------+-+-----------+-------++-+-----+-------+---------------+
3005   // |         |i|           |imm4   || |imm3 |       |imm8           |
3006   // +---------+-+-----------+-------++-+-----+-------+---------------+
3007
3008   // Extract the relocation addend from VAL based on the Thumb2
3009   // instruction encoding described above.
3010   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3011   extract_thumb_movw_movt_addend(
3012       typename elfcpp::Swap<32, big_endian>::Valtype val)
3013   {
3014     // According to the Elf ABI for ARM Architecture the immediate
3015     // field is sign-extended to form the addend.
3016     return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
3017                                    | ((val >> 15) & 0x0800)
3018                                    | ((val >> 4) & 0x0700)
3019                                    | (val & 0x00ff));
3020   }
3021
3022   // Insert X into VAL based on the Thumb2 instruction encoding
3023   // described above.
3024   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3025   insert_val_thumb_movw_movt(
3026       typename elfcpp::Swap<32, big_endian>::Valtype val,
3027       typename elfcpp::Swap<32, big_endian>::Valtype x)
3028   {
3029     val &= 0xfbf08f00;
3030     val |= (x & 0xf000) << 4;
3031     val |= (x & 0x0800) << 15;
3032     val |= (x & 0x0700) << 4;
3033     val |= (x & 0x00ff);
3034     return val;
3035   }
3036
3037   // Calculate the smallest constant Kn for the specified residual.
3038   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3039   static uint32_t
3040   calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3041   {
3042     int32_t msb;
3043
3044     if (residual == 0)
3045       return 0;
3046     // Determine the most significant bit in the residual and
3047     // align the resulting value to a 2-bit boundary.
3048     for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3049       ;
3050     // The desired shift is now (msb - 6), or zero, whichever
3051     // is the greater.
3052     return (((msb - 6) < 0) ? 0 : (msb - 6));
3053   }
3054
3055   // Calculate the final residual for the specified group index.
3056   // If the passed group index is less than zero, the method will return
3057   // the value of the specified residual without any change.
3058   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3059   static typename elfcpp::Swap<32, big_endian>::Valtype
3060   calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3061                     const int group)
3062   {
3063     for (int n = 0; n <= group; n++)
3064       {
3065         // Calculate which part of the value to mask.
3066         uint32_t shift = calc_grp_kn(residual);
3067         // Calculate the residual for the next time around.
3068         residual &= ~(residual & (0xff << shift));
3069       }
3070
3071     return residual;
3072   }
3073
3074   // Calculate the value of Gn for the specified group index.
3075   // We return it in the form of an encoded constant-and-rotation.
3076   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3077   static typename elfcpp::Swap<32, big_endian>::Valtype
3078   calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3079               const int group)
3080   {
3081     typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3082     uint32_t shift = 0;
3083
3084     for (int n = 0; n <= group; n++)
3085       {
3086         // Calculate which part of the value to mask.
3087         shift = calc_grp_kn(residual);
3088         // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3089         gn = residual & (0xff << shift);
3090         // Calculate the residual for the next time around.
3091         residual &= ~gn;
3092       }
3093     // Return Gn in the form of an encoded constant-and-rotation.
3094     return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3095   }
3096
3097  public:
3098   // Handle ARM long branches.
3099   static typename This::Status
3100   arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3101                     unsigned char*, const Sized_symbol<32>*,
3102                     const Arm_relobj<big_endian>*, unsigned int,
3103                     const Symbol_value<32>*, Arm_address, Arm_address, bool);
3104
3105   // Handle THUMB long branches.
3106   static typename This::Status
3107   thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3108                       unsigned char*, const Sized_symbol<32>*,
3109                       const Arm_relobj<big_endian>*, unsigned int,
3110                       const Symbol_value<32>*, Arm_address, Arm_address, bool);
3111
3112
3113   // Return the branch offset of a 32-bit THUMB branch.
3114   static inline int32_t
3115   thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3116   {
3117     // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3118     // involving the J1 and J2 bits.
3119     uint32_t s = (upper_insn & (1U << 10)) >> 10;
3120     uint32_t upper = upper_insn & 0x3ffU;
3121     uint32_t lower = lower_insn & 0x7ffU;
3122     uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3123     uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3124     uint32_t i1 = j1 ^ s ? 0 : 1;
3125     uint32_t i2 = j2 ^ s ? 0 : 1;
3126
3127     return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3128                                    | (upper << 12) | (lower << 1));
3129   }
3130
3131   // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3132   // UPPER_INSN is the original upper instruction of the branch.  Caller is
3133   // responsible for overflow checking and BLX offset adjustment.
3134   static inline uint16_t
3135   thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3136   {
3137     uint32_t s = offset < 0 ? 1 : 0;
3138     uint32_t bits = static_cast<uint32_t>(offset);
3139     return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3140   }
3141
3142   // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3143   // LOWER_INSN is the original lower instruction of the branch.  Caller is
3144   // responsible for overflow checking and BLX offset adjustment.
3145   static inline uint16_t
3146   thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3147   {
3148     uint32_t s = offset < 0 ? 1 : 0;
3149     uint32_t bits = static_cast<uint32_t>(offset);
3150     return ((lower_insn & ~0x2fffU)
3151             | ((((bits >> 23) & 1) ^ !s) << 13)
3152             | ((((bits >> 22) & 1) ^ !s) << 11)
3153             | ((bits >> 1) & 0x7ffU));
3154   }
3155
3156   // Return the branch offset of a 32-bit THUMB conditional branch.
3157   static inline int32_t
3158   thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3159   {
3160     uint32_t s = (upper_insn & 0x0400U) >> 10;
3161     uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3162     uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3163     uint32_t lower = (lower_insn & 0x07ffU);
3164     uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3165
3166     return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3167   }
3168
3169   // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3170   // instruction.  UPPER_INSN is the original upper instruction of the branch.
3171   // Caller is responsible for overflow checking.
3172   static inline uint16_t
3173   thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3174   {
3175     uint32_t s = offset < 0 ? 1 : 0;
3176     uint32_t bits = static_cast<uint32_t>(offset);
3177     return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3178   }
3179
3180   // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3181   // instruction.  LOWER_INSN is the original lower instruction of the branch.
3182   // The caller is responsible for overflow checking.
3183   static inline uint16_t
3184   thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3185   {
3186     uint32_t bits = static_cast<uint32_t>(offset);
3187     uint32_t j2 = (bits & 0x00080000U) >> 19;
3188     uint32_t j1 = (bits & 0x00040000U) >> 18;
3189     uint32_t lo = (bits & 0x00000ffeU) >> 1;
3190
3191     return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3192   }
3193
3194   // R_ARM_ABS8: S + A
3195   static inline typename This::Status
3196   abs8(unsigned char* view,
3197        const Sized_relobj_file<32, big_endian>* object,
3198        const Symbol_value<32>* psymval)
3199   {
3200     typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3201     Valtype* wv = reinterpret_cast<Valtype*>(view);
3202     Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3203     int32_t addend = Bits<8>::sign_extend32(val);
3204     Arm_address x = psymval->value(object, addend);
3205     val = Bits<32>::bit_select32(val, x, 0xffU);
3206     elfcpp::Swap<8, big_endian>::writeval(wv, val);
3207
3208     // R_ARM_ABS8 permits signed or unsigned results.
3209     return (Bits<8>::has_signed_unsigned_overflow32(x)
3210             ? This::STATUS_OVERFLOW
3211             : This::STATUS_OKAY);
3212   }
3213
3214   // R_ARM_THM_ABS5: S + A
3215   static inline typename This::Status
3216   thm_abs5(unsigned char* view,
3217        const Sized_relobj_file<32, big_endian>* object,
3218        const Symbol_value<32>* psymval)
3219   {
3220     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3221     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3222     Valtype* wv = reinterpret_cast<Valtype*>(view);
3223     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3224     Reltype addend = (val & 0x7e0U) >> 6;
3225     Reltype x = psymval->value(object, addend);
3226     val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3227     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3228     return (Bits<5>::has_overflow32(x)
3229             ? This::STATUS_OVERFLOW
3230             : This::STATUS_OKAY);
3231   }
3232
3233   // R_ARM_ABS12: S + A
3234   static inline typename This::Status
3235   abs12(unsigned char* view,
3236         const Sized_relobj_file<32, big_endian>* object,
3237         const Symbol_value<32>* psymval)
3238   {
3239     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3240     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3241     Valtype* wv = reinterpret_cast<Valtype*>(view);
3242     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3243     Reltype addend = val & 0x0fffU;
3244     Reltype x = psymval->value(object, addend);
3245     val = Bits<32>::bit_select32(val, x, 0x0fffU);
3246     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3247     return (Bits<12>::has_overflow32(x)
3248             ? This::STATUS_OVERFLOW
3249             : This::STATUS_OKAY);
3250   }
3251
3252   // R_ARM_ABS16: S + A
3253   static inline typename This::Status
3254   abs16(unsigned char* view,
3255         const Sized_relobj_file<32, big_endian>* object,
3256         const Symbol_value<32>* psymval)
3257   {
3258     typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
3259     Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view);
3260     int32_t addend = Bits<16>::sign_extend32(val);
3261     Arm_address x = psymval->value(object, addend);
3262     val = Bits<32>::bit_select32(val, x, 0xffffU);
3263     elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val);
3264
3265     // R_ARM_ABS16 permits signed or unsigned results.
3266     return (Bits<16>::has_signed_unsigned_overflow32(x)
3267             ? This::STATUS_OVERFLOW
3268             : This::STATUS_OKAY);
3269   }
3270
3271   // R_ARM_ABS32: (S + A) | T
3272   static inline typename This::Status
3273   abs32(unsigned char* view,
3274         const Sized_relobj_file<32, big_endian>* object,
3275         const Symbol_value<32>* psymval,
3276         Arm_address thumb_bit)
3277   {
3278     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3279     Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3280     Valtype x = psymval->value(object, addend) | thumb_bit;
3281     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3282     return This::STATUS_OKAY;
3283   }
3284
3285   // R_ARM_REL32: (S + A) | T - P
3286   static inline typename This::Status
3287   rel32(unsigned char* view,
3288         const Sized_relobj_file<32, big_endian>* object,
3289         const Symbol_value<32>* psymval,
3290         Arm_address address,
3291         Arm_address thumb_bit)
3292   {
3293     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3294     Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3295     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3296     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3297     return This::STATUS_OKAY;
3298   }
3299
3300   // R_ARM_THM_JUMP24: (S + A) | T - P
3301   static typename This::Status
3302   thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3303              const Symbol_value<32>* psymval, Arm_address address,
3304              Arm_address thumb_bit);
3305
3306   // R_ARM_THM_JUMP6: S + A â€“ P
3307   static inline typename This::Status
3308   thm_jump6(unsigned char* view,
3309             const Sized_relobj_file<32, big_endian>* object,
3310             const Symbol_value<32>* psymval,
3311             Arm_address address)
3312   {
3313     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3314     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3315     Valtype* wv = reinterpret_cast<Valtype*>(view);
3316     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3317     // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3318     Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3319     Reltype x = (psymval->value(object, addend) - address);
3320     val = (val & 0xfd07) | ((x  & 0x0040) << 3) | ((val & 0x003e) << 2);
3321     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3322     // CZB does only forward jumps.
3323     return ((x > 0x007e)
3324             ? This::STATUS_OVERFLOW
3325             : This::STATUS_OKAY);
3326   }
3327
3328   // R_ARM_THM_JUMP8: S + A â€“ P
3329   static inline typename This::Status
3330   thm_jump8(unsigned char* view,
3331             const Sized_relobj_file<32, big_endian>* object,
3332             const Symbol_value<32>* psymval,
3333             Arm_address address)
3334   {
3335     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3336     Valtype* wv = reinterpret_cast<Valtype*>(view);
3337     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3338     int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1);
3339     int32_t x = (psymval->value(object, addend) - address);
3340     elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00)
3341                                                 | ((x & 0x01fe) >> 1)));
3342     // We do a 9-bit overflow check because x is right-shifted by 1 bit.
3343     return (Bits<9>::has_overflow32(x)
3344             ? This::STATUS_OVERFLOW
3345             : This::STATUS_OKAY);
3346   }
3347
3348   // R_ARM_THM_JUMP11: S + A â€“ P
3349   static inline typename This::Status
3350   thm_jump11(unsigned char* view,
3351             const Sized_relobj_file<32, big_endian>* object,
3352             const Symbol_value<32>* psymval,
3353             Arm_address address)
3354   {
3355     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3356     Valtype* wv = reinterpret_cast<Valtype*>(view);
3357     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3358     int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1);
3359     int32_t x = (psymval->value(object, addend) - address);
3360     elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800)
3361                                                 | ((x & 0x0ffe) >> 1)));
3362     // We do a 12-bit overflow check because x is right-shifted by 1 bit.
3363     return (Bits<12>::has_overflow32(x)
3364             ? This::STATUS_OVERFLOW
3365             : This::STATUS_OKAY);
3366   }
3367
3368   // R_ARM_BASE_PREL: B(S) + A - P
3369   static inline typename This::Status
3370   base_prel(unsigned char* view,
3371             Arm_address origin,
3372             Arm_address address)
3373   {
3374     Base::rel32(view, origin - address);
3375     return STATUS_OKAY;
3376   }
3377
3378   // R_ARM_BASE_ABS: B(S) + A
3379   static inline typename This::Status
3380   base_abs(unsigned char* view,
3381            Arm_address origin)
3382   {
3383     Base::rel32(view, origin);
3384     return STATUS_OKAY;
3385   }
3386
3387   // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3388   static inline typename This::Status
3389   got_brel(unsigned char* view,
3390            typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3391   {
3392     Base::rel32(view, got_offset);
3393     return This::STATUS_OKAY;
3394   }
3395
3396   // R_ARM_GOT_PREL: GOT(S) + A - P
3397   static inline typename This::Status
3398   got_prel(unsigned char* view,
3399            Arm_address got_entry,
3400            Arm_address address)
3401   {
3402     Base::rel32(view, got_entry - address);
3403     return This::STATUS_OKAY;
3404   }
3405
3406   // R_ARM_PREL: (S + A) | T - P
3407   static inline typename This::Status
3408   prel31(unsigned char* view,
3409          const Sized_relobj_file<32, big_endian>* object,
3410          const Symbol_value<32>* psymval,
3411          Arm_address address,
3412          Arm_address thumb_bit)
3413   {
3414     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3415     Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3416     Valtype addend = Bits<31>::sign_extend32(val);
3417     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3418     val = Bits<32>::bit_select32(val, x, 0x7fffffffU);
3419     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val);
3420     return (Bits<31>::has_overflow32(x)
3421             ? This::STATUS_OVERFLOW
3422             : This::STATUS_OKAY);
3423   }
3424
3425   // R_ARM_MOVW_ABS_NC: (S + A) | T     (relative address base is )
3426   // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3427   // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3428   // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3429   static inline typename This::Status
3430   movw(unsigned char* view,
3431        const Sized_relobj_file<32, big_endian>* object,
3432        const Symbol_value<32>* psymval,
3433        Arm_address relative_address_base,
3434        Arm_address thumb_bit,
3435        bool check_overflow)
3436   {
3437     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3438     Valtype* wv = reinterpret_cast<Valtype*>(view);
3439     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3440     Valtype addend = This::extract_arm_movw_movt_addend(val);
3441     Valtype x = ((psymval->value(object, addend) | thumb_bit)
3442                  - relative_address_base);
3443     val = This::insert_val_arm_movw_movt(val, x);
3444     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3445     return ((check_overflow && Bits<16>::has_overflow32(x))
3446             ? This::STATUS_OVERFLOW
3447             : This::STATUS_OKAY);
3448   }
3449
3450   // R_ARM_MOVT_ABS: S + A      (relative address base is 0)
3451   // R_ARM_MOVT_PREL: S + A - P
3452   // R_ARM_MOVT_BREL: S + A - B(S)
3453   static inline typename This::Status
3454   movt(unsigned char* view,
3455        const Sized_relobj_file<32, big_endian>* object,
3456        const Symbol_value<32>* psymval,
3457        Arm_address relative_address_base)
3458   {
3459     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3460     Valtype* wv = reinterpret_cast<Valtype*>(view);
3461     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3462     Valtype addend = This::extract_arm_movw_movt_addend(val);
3463     Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3464     val = This::insert_val_arm_movw_movt(val, x);
3465     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3466     // FIXME: IHI0044D says that we should check for overflow.
3467     return This::STATUS_OKAY;
3468   }
3469
3470   // R_ARM_THM_MOVW_ABS_NC: S + A | T           (relative_address_base is 0)
3471   // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3472   // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3473   // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3474   static inline typename This::Status
3475   thm_movw(unsigned char* view,
3476            const Sized_relobj_file<32, big_endian>* object,
3477            const Symbol_value<32>* psymval,
3478            Arm_address relative_address_base,
3479            Arm_address thumb_bit,
3480            bool check_overflow)
3481   {
3482     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3483     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3484     Valtype* wv = reinterpret_cast<Valtype*>(view);
3485     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3486                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3487     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3488     Reltype x =
3489       (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3490     val = This::insert_val_thumb_movw_movt(val, x);
3491     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3492     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3493     return ((check_overflow && Bits<16>::has_overflow32(x))
3494             ? This::STATUS_OVERFLOW
3495             : This::STATUS_OKAY);
3496   }
3497
3498   // R_ARM_THM_MOVT_ABS: S + A          (relative address base is 0)
3499   // R_ARM_THM_MOVT_PREL: S + A - P
3500   // R_ARM_THM_MOVT_BREL: S + A - B(S)
3501   static inline typename This::Status
3502   thm_movt(unsigned char* view,
3503            const Sized_relobj_file<32, big_endian>* object,
3504            const Symbol_value<32>* psymval,
3505            Arm_address relative_address_base)
3506   {
3507     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3508     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3509     Valtype* wv = reinterpret_cast<Valtype*>(view);
3510     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3511                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3512     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3513     Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3514     val = This::insert_val_thumb_movw_movt(val, x);
3515     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3516     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3517     return This::STATUS_OKAY;
3518   }
3519
3520   // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3521   static inline typename This::Status
3522   thm_alu11(unsigned char* view,
3523             const Sized_relobj_file<32, big_endian>* object,
3524             const Symbol_value<32>* psymval,
3525             Arm_address address,
3526             Arm_address thumb_bit)
3527   {
3528     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3529     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3530     Valtype* wv = reinterpret_cast<Valtype*>(view);
3531     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3532                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3533
3534     //        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
3535     // -----------------------------------------------------------------------
3536     // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd     |imm8
3537     // ADDW   1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd     |imm8
3538     // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd     |imm8
3539     // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd     |imm8
3540     // SUBW   1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd     |imm8
3541     // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd     |imm8
3542
3543     // Determine a sign for the addend.
3544     const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3545                       || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3546     // Thumb2 addend encoding:
3547     // imm12 := i | imm3 | imm8
3548     int32_t addend = (insn & 0xff)
3549                      | ((insn & 0x00007000) >> 4)
3550                      | ((insn & 0x04000000) >> 15);
3551     // Apply a sign to the added.
3552     addend *= sign;
3553
3554     int32_t x = (psymval->value(object, addend) | thumb_bit)
3555                 - (address & 0xfffffffc);
3556     Reltype val = abs(x);
3557     // Mask out the value and a distinct part of the ADD/SUB opcode
3558     // (bits 7:5 of opword).
3559     insn = (insn & 0xfb0f8f00)
3560            | (val & 0xff)
3561            | ((val & 0x700) << 4)
3562            | ((val & 0x800) << 15);
3563     // Set the opcode according to whether the value to go in the
3564     // place is negative.
3565     if (x < 0)
3566       insn |= 0x00a00000;
3567
3568     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3569     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3570     return ((val > 0xfff) ?
3571             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3572   }
3573
3574   // R_ARM_THM_PC8: S + A - Pa (Thumb)
3575   static inline typename This::Status
3576   thm_pc8(unsigned char* view,
3577           const Sized_relobj_file<32, big_endian>* object,
3578           const Symbol_value<32>* psymval,
3579           Arm_address address)
3580   {
3581     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3582     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3583     Valtype* wv = reinterpret_cast<Valtype*>(view);
3584     Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3585     Reltype addend = ((insn & 0x00ff) << 2);
3586     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3587     Reltype val = abs(x);
3588     insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3589
3590     elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3591     return ((val > 0x03fc)
3592             ? This::STATUS_OVERFLOW
3593             : This::STATUS_OKAY);
3594   }
3595
3596   // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3597   static inline typename This::Status
3598   thm_pc12(unsigned char* view,
3599            const Sized_relobj_file<32, big_endian>* object,
3600            const Symbol_value<32>* psymval,
3601            Arm_address address)
3602   {
3603     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3604     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3605     Valtype* wv = reinterpret_cast<Valtype*>(view);
3606     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3607                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3608     // Determine a sign for the addend (positive if the U bit is 1).
3609     const int sign = (insn & 0x00800000) ? 1 : -1;
3610     int32_t addend = (insn & 0xfff);
3611     // Apply a sign to the added.
3612     addend *= sign;
3613
3614     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3615     Reltype val = abs(x);
3616     // Mask out and apply the value and the U bit.
3617     insn = (insn & 0xff7ff000) | (val & 0xfff);
3618     // Set the U bit according to whether the value to go in the
3619     // place is positive.
3620     if (x >= 0)
3621       insn |= 0x00800000;
3622
3623     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3624     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3625     return ((val > 0xfff) ?
3626             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3627   }
3628
3629   // R_ARM_V4BX
3630   static inline typename This::Status
3631   v4bx(const Relocate_info<32, big_endian>* relinfo,
3632        unsigned char* view,
3633        const Arm_relobj<big_endian>* object,
3634        const Arm_address address,
3635        const bool is_interworking)
3636   {
3637
3638     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3639     Valtype* wv = reinterpret_cast<Valtype*>(view);
3640     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3641
3642     // Ensure that we have a BX instruction.
3643     gold_assert((val & 0x0ffffff0) == 0x012fff10);
3644     const uint32_t reg = (val & 0xf);
3645     if (is_interworking && reg != 0xf)
3646       {
3647         Stub_table<big_endian>* stub_table =
3648             object->stub_table(relinfo->data_shndx);
3649         gold_assert(stub_table != NULL);
3650
3651         Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3652         gold_assert(stub != NULL);
3653
3654         int32_t veneer_address =
3655             stub_table->address() + stub->offset() - 8 - address;
3656         gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3657                     && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3658         // Replace with a branch to veneer (B <addr>)
3659         val = (val & 0xf0000000) | 0x0a000000
3660               | ((veneer_address >> 2) & 0x00ffffff);
3661       }
3662     else
3663       {
3664         // Preserve Rm (lowest four bits) and the condition code
3665         // (highest four bits). Other bits encode MOV PC,Rm.
3666         val = (val & 0xf000000f) | 0x01a0f000;
3667       }
3668     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3669     return This::STATUS_OKAY;
3670   }
3671
3672   // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3673   // R_ARM_ALU_PC_G0:    ((S + A) | T) - P
3674   // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3675   // R_ARM_ALU_PC_G1:    ((S + A) | T) - P
3676   // R_ARM_ALU_PC_G2:    ((S + A) | T) - P
3677   // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3678   // R_ARM_ALU_SB_G0:    ((S + A) | T) - B(S)
3679   // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3680   // R_ARM_ALU_SB_G1:    ((S + A) | T) - B(S)
3681   // R_ARM_ALU_SB_G2:    ((S + A) | T) - B(S)
3682   static inline typename This::Status
3683   arm_grp_alu(unsigned char* view,
3684         const Sized_relobj_file<32, big_endian>* object,
3685         const Symbol_value<32>* psymval,
3686         const int group,
3687         Arm_address address,
3688         Arm_address thumb_bit,
3689         bool check_overflow)
3690   {
3691     gold_assert(group >= 0 && group < 3);
3692     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3693     Valtype* wv = reinterpret_cast<Valtype*>(view);
3694     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3695
3696     // ALU group relocations are allowed only for the ADD/SUB instructions.
3697     // (0x00800000 - ADD, 0x00400000 - SUB)
3698     const Valtype opcode = insn & 0x01e00000;
3699     if (opcode != 0x00800000 && opcode != 0x00400000)
3700       return This::STATUS_BAD_RELOC;
3701
3702     // Determine a sign for the addend.
3703     const int sign = (opcode == 0x00800000) ? 1 : -1;
3704     // shifter = rotate_imm * 2
3705     const uint32_t shifter = (insn & 0xf00) >> 7;
3706     // Initial addend value.
3707     int32_t addend = insn & 0xff;
3708     // Rotate addend right by shifter.
3709     addend = (addend >> shifter) | (addend << (32 - shifter));
3710     // Apply a sign to the added.
3711     addend *= sign;
3712
3713     int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3714     Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3715     // Check for overflow if required
3716     if (check_overflow
3717         && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3718       return This::STATUS_OVERFLOW;
3719
3720     // Mask out the value and the ADD/SUB part of the opcode; take care
3721     // not to destroy the S bit.
3722     insn &= 0xff1ff000;
3723     // Set the opcode according to whether the value to go in the
3724     // place is negative.
3725     insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3726     // Encode the offset (encoded Gn).
3727     insn |= gn;
3728
3729     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3730     return This::STATUS_OKAY;
3731   }
3732
3733   // R_ARM_LDR_PC_G0: S + A - P
3734   // R_ARM_LDR_PC_G1: S + A - P
3735   // R_ARM_LDR_PC_G2: S + A - P
3736   // R_ARM_LDR_SB_G0: S + A - B(S)
3737   // R_ARM_LDR_SB_G1: S + A - B(S)
3738   // R_ARM_LDR_SB_G2: S + A - B(S)
3739   static inline typename This::Status
3740   arm_grp_ldr(unsigned char* view,
3741         const Sized_relobj_file<32, big_endian>* object,
3742         const Symbol_value<32>* psymval,
3743         const int group,
3744         Arm_address address)
3745   {
3746     gold_assert(group >= 0 && group < 3);
3747     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3748     Valtype* wv = reinterpret_cast<Valtype*>(view);
3749     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3750
3751     const int sign = (insn & 0x00800000) ? 1 : -1;
3752     int32_t addend = (insn & 0xfff) * sign;
3753     int32_t x = (psymval->value(object, addend) - address);
3754     // Calculate the relevant G(n-1) value to obtain this stage residual.
3755     Valtype residual =
3756         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3757     if (residual >= 0x1000)
3758       return This::STATUS_OVERFLOW;
3759
3760     // Mask out the value and U bit.
3761     insn &= 0xff7ff000;
3762     // Set the U bit for non-negative values.
3763     if (x >= 0)
3764       insn |= 0x00800000;
3765     insn |= residual;
3766
3767     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3768     return This::STATUS_OKAY;
3769   }
3770
3771   // R_ARM_LDRS_PC_G0: S + A - P
3772   // R_ARM_LDRS_PC_G1: S + A - P
3773   // R_ARM_LDRS_PC_G2: S + A - P
3774   // R_ARM_LDRS_SB_G0: S + A - B(S)
3775   // R_ARM_LDRS_SB_G1: S + A - B(S)
3776   // R_ARM_LDRS_SB_G2: S + A - B(S)
3777   static inline typename This::Status
3778   arm_grp_ldrs(unsigned char* view,
3779         const Sized_relobj_file<32, big_endian>* object,
3780         const Symbol_value<32>* psymval,
3781         const int group,
3782         Arm_address address)
3783   {
3784     gold_assert(group >= 0 && group < 3);
3785     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3786     Valtype* wv = reinterpret_cast<Valtype*>(view);
3787     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3788
3789     const int sign = (insn & 0x00800000) ? 1 : -1;
3790     int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3791     int32_t x = (psymval->value(object, addend) - address);
3792     // Calculate the relevant G(n-1) value to obtain this stage residual.
3793     Valtype residual =
3794         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3795    if (residual >= 0x100)
3796       return This::STATUS_OVERFLOW;
3797
3798     // Mask out the value and U bit.
3799     insn &= 0xff7ff0f0;
3800     // Set the U bit for non-negative values.
3801     if (x >= 0)
3802       insn |= 0x00800000;
3803     insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3804
3805     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3806     return This::STATUS_OKAY;
3807   }
3808
3809   // R_ARM_LDC_PC_G0: S + A - P
3810   // R_ARM_LDC_PC_G1: S + A - P
3811   // R_ARM_LDC_PC_G2: S + A - P
3812   // R_ARM_LDC_SB_G0: S + A - B(S)
3813   // R_ARM_LDC_SB_G1: S + A - B(S)
3814   // R_ARM_LDC_SB_G2: S + A - B(S)
3815   static inline typename This::Status
3816   arm_grp_ldc(unsigned char* view,
3817       const Sized_relobj_file<32, big_endian>* object,
3818       const Symbol_value<32>* psymval,
3819       const int group,
3820       Arm_address address)
3821   {
3822     gold_assert(group >= 0 && group < 3);
3823     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3824     Valtype* wv = reinterpret_cast<Valtype*>(view);
3825     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3826
3827     const int sign = (insn & 0x00800000) ? 1 : -1;
3828     int32_t addend = ((insn & 0xff) << 2) * sign;
3829     int32_t x = (psymval->value(object, addend) - address);
3830     // Calculate the relevant G(n-1) value to obtain this stage residual.
3831     Valtype residual =
3832       Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3833     if ((residual & 0x3) != 0 || residual >= 0x400)
3834       return This::STATUS_OVERFLOW;
3835
3836     // Mask out the value and U bit.
3837     insn &= 0xff7fff00;
3838     // Set the U bit for non-negative values.
3839     if (x >= 0)
3840       insn |= 0x00800000;
3841     insn |= (residual >> 2);
3842
3843     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3844     return This::STATUS_OKAY;
3845   }
3846 };
3847
3848 // Relocate ARM long branches.  This handles relocation types
3849 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3850 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3851 // undefined and we do not use PLT in this relocation.  In such a case,
3852 // the branch is converted into an NOP.
3853
3854 template<bool big_endian>
3855 typename Arm_relocate_functions<big_endian>::Status
3856 Arm_relocate_functions<big_endian>::arm_branch_common(
3857     unsigned int r_type,
3858     const Relocate_info<32, big_endian>* relinfo,
3859     unsigned char* view,
3860     const Sized_symbol<32>* gsym,
3861     const Arm_relobj<big_endian>* object,
3862     unsigned int r_sym,
3863     const Symbol_value<32>* psymval,
3864     Arm_address address,
3865     Arm_address thumb_bit,
3866     bool is_weakly_undefined_without_plt)
3867 {
3868   typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3869   Valtype* wv = reinterpret_cast<Valtype*>(view);
3870   Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3871
3872   bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3873                     && ((val & 0x0f000000UL) == 0x0a000000UL);
3874   bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3875   bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3876                           && ((val & 0x0f000000UL) == 0x0b000000UL);
3877   bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3878   bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3879
3880   // Check that the instruction is valid.
3881   if (r_type == elfcpp::R_ARM_CALL)
3882     {
3883       if (!insn_is_uncond_bl && !insn_is_blx)
3884         return This::STATUS_BAD_RELOC;
3885     }
3886   else if (r_type == elfcpp::R_ARM_JUMP24)
3887     {
3888       if (!insn_is_b && !insn_is_cond_bl)
3889         return This::STATUS_BAD_RELOC;
3890     }
3891   else if (r_type == elfcpp::R_ARM_PLT32)
3892     {
3893       if (!insn_is_any_branch)
3894         return This::STATUS_BAD_RELOC;
3895     }
3896   else if (r_type == elfcpp::R_ARM_XPC25)
3897     {
3898       // FIXME: AAELF document IH0044C does not say much about it other
3899       // than it being obsolete.
3900       if (!insn_is_any_branch)
3901         return This::STATUS_BAD_RELOC;
3902     }
3903   else
3904     gold_unreachable();
3905
3906   // A branch to an undefined weak symbol is turned into a jump to
3907   // the next instruction unless a PLT entry will be created.
3908   // Do the same for local undefined symbols.
3909   // The jump to the next instruction is optimized as a NOP depending
3910   // on the architecture.
3911   const Target_arm<big_endian>* arm_target =
3912     Target_arm<big_endian>::default_target();
3913   if (is_weakly_undefined_without_plt)
3914     {
3915       gold_assert(!parameters->options().relocatable());
3916       Valtype cond = val & 0xf0000000U;
3917       if (arm_target->may_use_arm_nop())
3918         val = cond | 0x0320f000;
3919       else
3920         val = cond | 0x01a00000;        // Using pre-UAL nop: mov r0, r0.
3921       elfcpp::Swap<32, big_endian>::writeval(wv, val);
3922       return This::STATUS_OKAY;
3923     }
3924
3925   Valtype addend = Bits<26>::sign_extend32(val << 2);
3926   Valtype branch_target = psymval->value(object, addend);
3927   int32_t branch_offset = branch_target - address;
3928
3929   // We need a stub if the branch offset is too large or if we need
3930   // to switch mode.
3931   bool may_use_blx = arm_target->may_use_v5t_interworking();
3932   Reloc_stub* stub = NULL;
3933
3934   if (!parameters->options().relocatable()
3935       && (Bits<26>::has_overflow32(branch_offset)
3936           || ((thumb_bit != 0)
3937               && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3938     {
3939       Valtype unadjusted_branch_target = psymval->value(object, 0);
3940
3941       Stub_type stub_type =
3942         Reloc_stub::stub_type_for_reloc(r_type, address,
3943                                         unadjusted_branch_target,
3944                                         (thumb_bit != 0));
3945       if (stub_type != arm_stub_none)
3946         {
3947           Stub_table<big_endian>* stub_table =
3948             object->stub_table(relinfo->data_shndx);
3949           gold_assert(stub_table != NULL);
3950
3951           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3952           stub = stub_table->find_reloc_stub(stub_key);
3953           gold_assert(stub != NULL);
3954           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3955           branch_target = stub_table->address() + stub->offset() + addend;
3956           branch_offset = branch_target - address;
3957           gold_assert(!Bits<26>::has_overflow32(branch_offset));
3958         }
3959     }
3960
3961   // At this point, if we still need to switch mode, the instruction
3962   // must either be a BLX or a BL that can be converted to a BLX.
3963   if (thumb_bit != 0)
3964     {
3965       // Turn BL to BLX.
3966       gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3967       val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3968     }
3969
3970   val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL);
3971   elfcpp::Swap<32, big_endian>::writeval(wv, val);
3972   return (Bits<26>::has_overflow32(branch_offset)
3973           ? This::STATUS_OVERFLOW
3974           : This::STATUS_OKAY);
3975 }
3976
3977 // Relocate THUMB long branches.  This handles relocation types
3978 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3979 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3980 // undefined and we do not use PLT in this relocation.  In such a case,
3981 // the branch is converted into an NOP.
3982
3983 template<bool big_endian>
3984 typename Arm_relocate_functions<big_endian>::Status
3985 Arm_relocate_functions<big_endian>::thumb_branch_common(
3986     unsigned int r_type,
3987     const Relocate_info<32, big_endian>* relinfo,
3988     unsigned char* view,
3989     const Sized_symbol<32>* gsym,
3990     const Arm_relobj<big_endian>* object,
3991     unsigned int r_sym,
3992     const Symbol_value<32>* psymval,
3993     Arm_address address,
3994     Arm_address thumb_bit,
3995     bool is_weakly_undefined_without_plt)
3996 {
3997   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3998   Valtype* wv = reinterpret_cast<Valtype*>(view);
3999   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4000   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4001
4002   // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
4003   // into account.
4004   bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
4005   bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
4006
4007   // Check that the instruction is valid.
4008   if (r_type == elfcpp::R_ARM_THM_CALL)
4009     {
4010       if (!is_bl_insn && !is_blx_insn)
4011         return This::STATUS_BAD_RELOC;
4012     }
4013   else if (r_type == elfcpp::R_ARM_THM_JUMP24)
4014     {
4015       // This cannot be a BLX.
4016       if (!is_bl_insn)
4017         return This::STATUS_BAD_RELOC;
4018     }
4019   else if (r_type == elfcpp::R_ARM_THM_XPC22)
4020     {
4021       // Check for Thumb to Thumb call.
4022       if (!is_blx_insn)
4023         return This::STATUS_BAD_RELOC;
4024       if (thumb_bit != 0)
4025         {
4026           gold_warning(_("%s: Thumb BLX instruction targets "
4027                          "thumb function '%s'."),
4028                          object->name().c_str(),
4029                          (gsym ? gsym->name() : "(local)"));
4030           // Convert BLX to BL.
4031           lower_insn |= 0x1000U;
4032         }
4033     }
4034   else
4035     gold_unreachable();
4036
4037   // A branch to an undefined weak symbol is turned into a jump to
4038   // the next instruction unless a PLT entry will be created.
4039   // The jump to the next instruction is optimized as a NOP.W for
4040   // Thumb-2 enabled architectures.
4041   const Target_arm<big_endian>* arm_target =
4042     Target_arm<big_endian>::default_target();
4043   if (is_weakly_undefined_without_plt)
4044     {
4045       gold_assert(!parameters->options().relocatable());
4046       if (arm_target->may_use_thumb2_nop())
4047         {
4048           elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4049           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4050         }
4051       else
4052         {
4053           elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4054           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4055         }
4056       return This::STATUS_OKAY;
4057     }
4058
4059   int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4060   Arm_address branch_target = psymval->value(object, addend);
4061
4062   // For BLX, bit 1 of target address comes from bit 1 of base address.
4063   bool may_use_blx = arm_target->may_use_v5t_interworking();
4064   if (thumb_bit == 0 && may_use_blx)
4065     branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4066
4067   int32_t branch_offset = branch_target - address;
4068
4069   // We need a stub if the branch offset is too large or if we need
4070   // to switch mode.
4071   bool thumb2 = arm_target->using_thumb2();
4072   if (!parameters->options().relocatable()
4073       && ((!thumb2 && Bits<23>::has_overflow32(branch_offset))
4074           || (thumb2 && Bits<25>::has_overflow32(branch_offset))
4075           || ((thumb_bit == 0)
4076               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4077                   || r_type == elfcpp::R_ARM_THM_JUMP24))))
4078     {
4079       Arm_address unadjusted_branch_target = psymval->value(object, 0);
4080
4081       Stub_type stub_type =
4082         Reloc_stub::stub_type_for_reloc(r_type, address,
4083                                         unadjusted_branch_target,
4084                                         (thumb_bit != 0));
4085
4086       if (stub_type != arm_stub_none)
4087         {
4088           Stub_table<big_endian>* stub_table =
4089             object->stub_table(relinfo->data_shndx);
4090           gold_assert(stub_table != NULL);
4091
4092           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4093           Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4094           gold_assert(stub != NULL);
4095           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4096           branch_target = stub_table->address() + stub->offset() + addend;
4097           if (thumb_bit == 0 && may_use_blx)
4098             branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4099           branch_offset = branch_target - address;
4100         }
4101     }
4102
4103   // At this point, if we still need to switch mode, the instruction
4104   // must either be a BLX or a BL that can be converted to a BLX.
4105   if (thumb_bit == 0)
4106     {
4107       gold_assert(may_use_blx
4108                   && (r_type == elfcpp::R_ARM_THM_CALL
4109                       || r_type == elfcpp::R_ARM_THM_XPC22));
4110       // Make sure this is a BLX.
4111       lower_insn &= ~0x1000U;
4112     }
4113   else
4114     {
4115       // Make sure this is a BL.
4116       lower_insn |= 0x1000U;
4117     }
4118
4119   // For a BLX instruction, make sure that the relocation is rounded up
4120   // to a word boundary.  This follows the semantics of the instruction
4121   // which specifies that bit 1 of the target address will come from bit
4122   // 1 of the base address.
4123   if ((lower_insn & 0x5000U) == 0x4000U)
4124     gold_assert((branch_offset & 3) == 0);
4125
4126   // Put BRANCH_OFFSET back into the insn.  Assumes two's complement.
4127   // We use the Thumb-2 encoding, which is safe even if dealing with
4128   // a Thumb-1 instruction by virtue of our overflow check above.  */
4129   upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4130   lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4131
4132   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4133   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4134
4135   gold_assert(!Bits<25>::has_overflow32(branch_offset));
4136
4137   return ((thumb2
4138            ? Bits<25>::has_overflow32(branch_offset)
4139            : Bits<23>::has_overflow32(branch_offset))
4140           ? This::STATUS_OVERFLOW
4141           : This::STATUS_OKAY);
4142 }
4143
4144 // Relocate THUMB-2 long conditional branches.
4145 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
4146 // undefined and we do not use PLT in this relocation.  In such a case,
4147 // the branch is converted into an NOP.
4148
4149 template<bool big_endian>
4150 typename Arm_relocate_functions<big_endian>::Status
4151 Arm_relocate_functions<big_endian>::thm_jump19(
4152     unsigned char* view,
4153     const Arm_relobj<big_endian>* object,
4154     const Symbol_value<32>* psymval,
4155     Arm_address address,
4156     Arm_address thumb_bit)
4157 {
4158   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4159   Valtype* wv = reinterpret_cast<Valtype*>(view);
4160   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4161   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4162   int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4163
4164   Arm_address branch_target = psymval->value(object, addend);
4165   int32_t branch_offset = branch_target - address;
4166
4167   // ??? Should handle interworking?  GCC might someday try to
4168   // use this for tail calls.
4169   // FIXME: We do support thumb entry to PLT yet.
4170   if (thumb_bit == 0)
4171     {
4172       gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4173       return This::STATUS_BAD_RELOC;
4174     }
4175
4176   // Put RELOCATION back into the insn.
4177   upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4178   lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4179
4180   // Put the relocated value back in the object file:
4181   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4182   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4183
4184   return (Bits<21>::has_overflow32(branch_offset)
4185           ? This::STATUS_OVERFLOW
4186           : This::STATUS_OKAY);
4187 }
4188
4189 // Get the GOT section, creating it if necessary.
4190
4191 template<bool big_endian>
4192 Arm_output_data_got<big_endian>*
4193 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4194 {
4195   if (this->got_ == NULL)
4196     {
4197       gold_assert(symtab != NULL && layout != NULL);
4198
4199       // When using -z now, we can treat .got as a relro section.
4200       // Without -z now, it is modified after program startup by lazy
4201       // PLT relocations.
4202       bool is_got_relro = parameters->options().now();
4203       Output_section_order got_order = (is_got_relro
4204                                         ? ORDER_RELRO_LAST
4205                                         : ORDER_DATA);
4206
4207       // Unlike some targets (.e.g x86), ARM does not use separate .got and
4208       // .got.plt sections in output.  The output .got section contains both
4209       // PLT and non-PLT GOT entries.
4210       this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4211
4212       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4213                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4214                                       this->got_, got_order, is_got_relro);
4215
4216       // The old GNU linker creates a .got.plt section.  We just
4217       // create another set of data in the .got section.  Note that we
4218       // always create a PLT if we create a GOT, although the PLT
4219       // might be empty.
4220       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4221       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4222                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4223                                       this->got_plt_, got_order, is_got_relro);
4224
4225       // The first three entries are reserved.
4226       this->got_plt_->set_current_data_size(3 * 4);
4227
4228       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4229       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4230                                     Symbol_table::PREDEFINED,
4231                                     this->got_plt_,
4232                                     0, 0, elfcpp::STT_OBJECT,
4233                                     elfcpp::STB_LOCAL,
4234                                     elfcpp::STV_HIDDEN, 0,
4235                                     false, false);
4236     }
4237   return this->got_;
4238 }
4239
4240 // Get the dynamic reloc section, creating it if necessary.
4241
4242 template<bool big_endian>
4243 typename Target_arm<big_endian>::Reloc_section*
4244 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4245 {
4246   if (this->rel_dyn_ == NULL)
4247     {
4248       gold_assert(layout != NULL);
4249       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4250       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4251                                       elfcpp::SHF_ALLOC, this->rel_dyn_,
4252                                       ORDER_DYNAMIC_RELOCS, false);
4253     }
4254   return this->rel_dyn_;
4255 }
4256
4257 // Insn_template methods.
4258
4259 // Return byte size of an instruction template.
4260
4261 size_t
4262 Insn_template::size() const
4263 {
4264   switch (this->type())
4265     {
4266     case THUMB16_TYPE:
4267     case THUMB16_SPECIAL_TYPE:
4268       return 2;
4269     case ARM_TYPE:
4270     case THUMB32_TYPE:
4271     case DATA_TYPE:
4272       return 4;
4273     default:
4274       gold_unreachable();
4275     }
4276 }
4277
4278 // Return alignment of an instruction template.
4279
4280 unsigned
4281 Insn_template::alignment() const
4282 {
4283   switch (this->type())
4284     {
4285     case THUMB16_TYPE:
4286     case THUMB16_SPECIAL_TYPE:
4287     case THUMB32_TYPE:
4288       return 2;
4289     case ARM_TYPE:
4290     case DATA_TYPE:
4291       return 4;
4292     default:
4293       gold_unreachable();
4294     }
4295 }
4296
4297 // Stub_template methods.
4298
4299 Stub_template::Stub_template(
4300     Stub_type type, const Insn_template* insns,
4301      size_t insn_count)
4302   : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4303     entry_in_thumb_mode_(false), relocs_()
4304 {
4305   off_t offset = 0;
4306
4307   // Compute byte size and alignment of stub template.
4308   for (size_t i = 0; i < insn_count; i++)
4309     {
4310       unsigned insn_alignment = insns[i].alignment();
4311       size_t insn_size = insns[i].size();
4312       gold_assert((offset & (insn_alignment - 1)) == 0);
4313       this->alignment_ = std::max(this->alignment_, insn_alignment);
4314       switch (insns[i].type())
4315         {
4316         case Insn_template::THUMB16_TYPE:
4317         case Insn_template::THUMB16_SPECIAL_TYPE:
4318           if (i == 0)
4319             this->entry_in_thumb_mode_ = true;
4320           break;
4321
4322         case Insn_template::THUMB32_TYPE:
4323           if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4324             this->relocs_.push_back(Reloc(i, offset));
4325           if (i == 0)
4326             this->entry_in_thumb_mode_ = true;
4327           break;
4328
4329         case Insn_template::ARM_TYPE:
4330           // Handle cases where the target is encoded within the
4331           // instruction.
4332           if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4333             this->relocs_.push_back(Reloc(i, offset));
4334           break;
4335
4336         case Insn_template::DATA_TYPE:
4337           // Entry point cannot be data.
4338           gold_assert(i != 0);
4339           this->relocs_.push_back(Reloc(i, offset));
4340           break;
4341
4342         default:
4343           gold_unreachable();
4344         }
4345       offset += insn_size;
4346     }
4347   this->size_ = offset;
4348 }
4349
4350 // Stub methods.
4351
4352 // Template to implement do_write for a specific target endianness.
4353
4354 template<bool big_endian>
4355 void inline
4356 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4357 {
4358   const Stub_template* stub_template = this->stub_template();
4359   const Insn_template* insns = stub_template->insns();
4360
4361   // FIXME:  We do not handle BE8 encoding yet.
4362   unsigned char* pov = view;
4363   for (size_t i = 0; i < stub_template->insn_count(); i++)
4364     {
4365       switch (insns[i].type())
4366         {
4367         case Insn_template::THUMB16_TYPE:
4368           elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4369           break;
4370         case Insn_template::THUMB16_SPECIAL_TYPE:
4371           elfcpp::Swap<16, big_endian>::writeval(
4372               pov,
4373               this->thumb16_special(i));
4374           break;
4375         case Insn_template::THUMB32_TYPE:
4376           {
4377             uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4378             uint32_t lo = insns[i].data() & 0xffff;
4379             elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4380             elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4381           }
4382           break;
4383         case Insn_template::ARM_TYPE:
4384         case Insn_template::DATA_TYPE:
4385           elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4386           break;
4387         default:
4388           gold_unreachable();
4389         }
4390       pov += insns[i].size();
4391     }
4392   gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4393 }
4394
4395 // Reloc_stub::Key methods.
4396
4397 // Dump a Key as a string for debugging.
4398
4399 std::string
4400 Reloc_stub::Key::name() const
4401 {
4402   if (this->r_sym_ == invalid_index)
4403     {
4404       // Global symbol key name
4405       // <stub-type>:<symbol name>:<addend>.
4406       const std::string sym_name = this->u_.symbol->name();
4407       // We need to print two hex number and two colons.  So just add 100 bytes
4408       // to the symbol name size.
4409       size_t len = sym_name.size() + 100;
4410       char* buffer = new char[len];
4411       int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4412                        sym_name.c_str(), this->addend_);
4413       gold_assert(c > 0 && c < static_cast<int>(len));
4414       delete[] buffer;
4415       return std::string(buffer);
4416     }
4417   else
4418     {
4419       // local symbol key name
4420       // <stub-type>:<object>:<r_sym>:<addend>.
4421       const size_t len = 200;
4422       char buffer[len];
4423       int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4424                        this->u_.relobj, this->r_sym_, this->addend_);
4425       gold_assert(c > 0 && c < static_cast<int>(len));
4426       return std::string(buffer);
4427     }
4428 }
4429
4430 // Reloc_stub methods.
4431
4432 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4433 // LOCATION to DESTINATION.
4434 // This code is based on the arm_type_of_stub function in
4435 // bfd/elf32-arm.c.  We have changed the interface a little to keep the Stub
4436 // class simple.
4437
4438 Stub_type
4439 Reloc_stub::stub_type_for_reloc(
4440    unsigned int r_type,
4441    Arm_address location,
4442    Arm_address destination,
4443    bool target_is_thumb)
4444 {
4445   Stub_type stub_type = arm_stub_none;
4446
4447   // This is a bit ugly but we want to avoid using a templated class for
4448   // big and little endianities.
4449   bool may_use_blx;
4450   bool should_force_pic_veneer;
4451   bool thumb2;
4452   bool thumb_only;
4453   if (parameters->target().is_big_endian())
4454     {
4455       const Target_arm<true>* big_endian_target =
4456         Target_arm<true>::default_target();
4457       may_use_blx = big_endian_target->may_use_v5t_interworking();
4458       should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4459       thumb2 = big_endian_target->using_thumb2();
4460       thumb_only = big_endian_target->using_thumb_only();
4461     }
4462   else
4463     {
4464       const Target_arm<false>* little_endian_target =
4465         Target_arm<false>::default_target();
4466       may_use_blx = little_endian_target->may_use_v5t_interworking();
4467       should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4468       thumb2 = little_endian_target->using_thumb2();
4469       thumb_only = little_endian_target->using_thumb_only();
4470     }
4471
4472   int64_t branch_offset;
4473   bool output_is_position_independent =
4474       parameters->options().output_is_position_independent();
4475   if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4476     {
4477       // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4478       // base address (instruction address + 4).
4479       if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4480         destination = Bits<32>::bit_select32(destination, location, 0x2);
4481       branch_offset = static_cast<int64_t>(destination) - location;
4482
4483       // Handle cases where:
4484       // - this call goes too far (different Thumb/Thumb2 max
4485       //   distance)
4486       // - it's a Thumb->Arm call and blx is not available, or it's a
4487       //   Thumb->Arm branch (not bl). A stub is needed in this case.
4488       if ((!thumb2
4489             && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4490                 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4491           || (thumb2
4492               && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4493                   || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4494           || ((!target_is_thumb)
4495               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4496                   || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4497         {
4498           if (target_is_thumb)
4499             {
4500               // Thumb to thumb.
4501               if (!thumb_only)
4502                 {
4503                   stub_type = (output_is_position_independent
4504                                || should_force_pic_veneer)
4505                     // PIC stubs.
4506                     ? ((may_use_blx
4507                         && (r_type == elfcpp::R_ARM_THM_CALL))
4508                        // V5T and above. Stub starts with ARM code, so
4509                        // we must be able to switch mode before
4510                        // reaching it, which is only possible for 'bl'
4511                        // (ie R_ARM_THM_CALL relocation).
4512                        ? arm_stub_long_branch_any_thumb_pic
4513                        // On V4T, use Thumb code only.
4514                        : arm_stub_long_branch_v4t_thumb_thumb_pic)
4515
4516                     // non-PIC stubs.
4517                     : ((may_use_blx
4518                         && (r_type == elfcpp::R_ARM_THM_CALL))
4519                        ? arm_stub_long_branch_any_any // V5T and above.
4520                        : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4521                 }
4522               else
4523                 {
4524                   stub_type = (output_is_position_independent
4525                                || should_force_pic_veneer)
4526                     ? arm_stub_long_branch_thumb_only_pic       // PIC stub.
4527                     : arm_stub_long_branch_thumb_only;  // non-PIC stub.
4528                 }
4529             }
4530           else
4531             {
4532               // Thumb to arm.
4533
4534               // FIXME: We should check that the input section is from an
4535               // object that has interwork enabled.
4536
4537               stub_type = (output_is_position_independent
4538                            || should_force_pic_veneer)
4539                 // PIC stubs.
4540                 ? ((may_use_blx
4541                     && (r_type == elfcpp::R_ARM_THM_CALL))
4542                    ? arm_stub_long_branch_any_arm_pic   // V5T and above.
4543                    : arm_stub_long_branch_v4t_thumb_arm_pic)    // V4T.
4544
4545                 // non-PIC stubs.
4546                 : ((may_use_blx
4547                     && (r_type == elfcpp::R_ARM_THM_CALL))
4548                    ? arm_stub_long_branch_any_any       // V5T and above.
4549                    : arm_stub_long_branch_v4t_thumb_arm);       // V4T.
4550
4551               // Handle v4t short branches.
4552               if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4553                   && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4554                   && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4555                 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4556             }
4557         }
4558     }
4559   else if (r_type == elfcpp::R_ARM_CALL
4560            || r_type == elfcpp::R_ARM_JUMP24
4561            || r_type == elfcpp::R_ARM_PLT32)
4562     {
4563       branch_offset = static_cast<int64_t>(destination) - location;
4564       if (target_is_thumb)
4565         {
4566           // Arm to thumb.
4567
4568           // FIXME: We should check that the input section is from an
4569           // object that has interwork enabled.
4570
4571           // We have an extra 2-bytes reach because of
4572           // the mode change (bit 24 (H) of BLX encoding).
4573           if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4574               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4575               || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4576               || (r_type == elfcpp::R_ARM_JUMP24)
4577               || (r_type == elfcpp::R_ARM_PLT32))
4578             {
4579               stub_type = (output_is_position_independent
4580                            || should_force_pic_veneer)
4581                 // PIC stubs.
4582                 ? (may_use_blx
4583                    ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4584                    : arm_stub_long_branch_v4t_arm_thumb_pic)    // V4T stub.
4585
4586                 // non-PIC stubs.
4587                 : (may_use_blx
4588                    ? arm_stub_long_branch_any_any       // V5T and above.
4589                    : arm_stub_long_branch_v4t_arm_thumb);       // V4T.
4590             }
4591         }
4592       else
4593         {
4594           // Arm to arm.
4595           if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4596               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4597             {
4598               stub_type = (output_is_position_independent
4599                            || should_force_pic_veneer)
4600                 ? arm_stub_long_branch_any_arm_pic      // PIC stubs.
4601                 : arm_stub_long_branch_any_any;         /// non-PIC.
4602             }
4603         }
4604     }
4605
4606   return stub_type;
4607 }
4608
4609 // Cortex_a8_stub methods.
4610
4611 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4612 // I is the position of the instruction template in the stub template.
4613
4614 uint16_t
4615 Cortex_a8_stub::do_thumb16_special(size_t i)
4616 {
4617   // The only use of this is to copy condition code from a conditional
4618   // branch being worked around to the corresponding conditional branch in
4619   // to the stub.
4620   gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4621               && i == 0);
4622   uint16_t data = this->stub_template()->insns()[i].data();
4623   gold_assert((data & 0xff00U) == 0xd000U);
4624   data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4625   return data;
4626 }
4627
4628 // Stub_factory methods.
4629
4630 Stub_factory::Stub_factory()
4631 {
4632   // The instruction template sequences are declared as static
4633   // objects and initialized first time the constructor runs.
4634
4635   // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4636   // to reach the stub if necessary.
4637   static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4638     {
4639       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4640       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4641                                                 // dcd   R_ARM_ABS32(X)
4642     };
4643
4644   // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4645   // available.
4646   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4647     {
4648       Insn_template::arm_insn(0xe59fc000),      // ldr   ip, [pc, #0]
4649       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4650       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4651                                                 // dcd   R_ARM_ABS32(X)
4652     };
4653
4654   // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4655   static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4656     {
4657       Insn_template::thumb16_insn(0xb401),      // push {r0}
4658       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4659       Insn_template::thumb16_insn(0x4684),      // mov  ip, r0
4660       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4661       Insn_template::thumb16_insn(0x4760),      // bx   ip
4662       Insn_template::thumb16_insn(0xbf00),      // nop
4663       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4664                                                 // dcd  R_ARM_ABS32(X)
4665     };
4666
4667   // V4T Thumb -> Thumb long branch stub. Using the stack is not
4668   // allowed.
4669   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4670     {
4671       Insn_template::thumb16_insn(0x4778),      // bx   pc
4672       Insn_template::thumb16_insn(0x46c0),      // nop
4673       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4674       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4675       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4676                                                 // dcd  R_ARM_ABS32(X)
4677     };
4678
4679   // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4680   // available.
4681   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4682     {
4683       Insn_template::thumb16_insn(0x4778),      // bx   pc
4684       Insn_template::thumb16_insn(0x46c0),      // nop
4685       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4686       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4687                                                 // dcd   R_ARM_ABS32(X)
4688     };
4689
4690   // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4691   // one, when the destination is close enough.
4692   static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4693     {
4694       Insn_template::thumb16_insn(0x4778),              // bx   pc
4695       Insn_template::thumb16_insn(0x46c0),              // nop
4696       Insn_template::arm_rel_insn(0xea000000, -8),      // b    (X-8)
4697     };
4698
4699   // ARM/Thumb -> ARM long branch stub, PIC.  On V5T and above, use
4700   // blx to reach the stub if necessary.
4701   static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4702     {
4703       Insn_template::arm_insn(0xe59fc000),      // ldr   r12, [pc]
4704       Insn_template::arm_insn(0xe08ff00c),      // add   pc, pc, ip
4705       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4706                                                 // dcd   R_ARM_REL32(X-4)
4707     };
4708
4709   // ARM/Thumb -> Thumb long branch stub, PIC.  On V5T and above, use
4710   // blx to reach the stub if necessary.  We can not add into pc;
4711   // it is not guaranteed to mode switch (different in ARMv6 and
4712   // ARMv7).
4713   static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4714     {
4715       Insn_template::arm_insn(0xe59fc004),      // ldr   r12, [pc, #4]
4716       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4717       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4718       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4719                                                 // dcd   R_ARM_REL32(X)
4720     };
4721
4722   // V4T ARM -> ARM long branch stub, PIC.
4723   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4724     {
4725       Insn_template::arm_insn(0xe59fc004),      // ldr   ip, [pc, #4]
4726       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4727       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4728       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4729                                                 // dcd   R_ARM_REL32(X)
4730     };
4731
4732   // V4T Thumb -> ARM long branch stub, PIC.
4733   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4734     {
4735       Insn_template::thumb16_insn(0x4778),      // bx   pc
4736       Insn_template::thumb16_insn(0x46c0),      // nop
4737       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4738       Insn_template::arm_insn(0xe08cf00f),      // add  pc, ip, pc
4739       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4740                                                 // dcd  R_ARM_REL32(X)
4741     };
4742
4743   // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4744   // architectures.
4745   static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4746     {
4747       Insn_template::thumb16_insn(0xb401),      // push {r0}
4748       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4749       Insn_template::thumb16_insn(0x46fc),      // mov  ip, pc
4750       Insn_template::thumb16_insn(0x4484),      // add  ip, r0
4751       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4752       Insn_template::thumb16_insn(0x4760),      // bx   ip
4753       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4754                                                 // dcd  R_ARM_REL32(X)
4755     };
4756
4757   // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4758   // allowed.
4759   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4760     {
4761       Insn_template::thumb16_insn(0x4778),      // bx   pc
4762       Insn_template::thumb16_insn(0x46c0),      // nop
4763       Insn_template::arm_insn(0xe59fc004),      // ldr  ip, [pc, #4]
4764       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4765       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4766       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4767                                                 // dcd  R_ARM_REL32(X)
4768     };
4769
4770   // Cortex-A8 erratum-workaround stubs.
4771
4772   // Stub used for conditional branches (which may be beyond +/-1MB away,
4773   // so we can't use a conditional branch to reach this stub).
4774
4775   // original code:
4776   //
4777   //    b<cond> X
4778   // after:
4779   //
4780   static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4781     {
4782       Insn_template::thumb16_bcond_insn(0xd001),        //      b<cond>.n true
4783       Insn_template::thumb32_b_insn(0xf000b800, -4),    //      b.w after
4784       Insn_template::thumb32_b_insn(0xf000b800, -4)     // true:
4785                                                         //      b.w X
4786     };
4787
4788   // Stub used for b.w and bl.w instructions.
4789
4790   static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4791     {
4792       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4793     };
4794
4795   static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4796     {
4797       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4798     };
4799
4800   // Stub used for Thumb-2 blx.w instructions.  We modified the original blx.w
4801   // instruction (which switches to ARM mode) to point to this stub.  Jump to
4802   // the real destination using an ARM-mode branch.
4803   static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4804     {
4805       Insn_template::arm_rel_insn(0xea000000, -8)       // b dest
4806     };
4807
4808   // Stub used to provide an interworking for R_ARM_V4BX relocation
4809   // (bx r[n] instruction).
4810   static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4811     {
4812       Insn_template::arm_insn(0xe3100001),              // tst   r<n>, #1
4813       Insn_template::arm_insn(0x01a0f000),              // moveq pc, r<n>
4814       Insn_template::arm_insn(0xe12fff10)               // bx    r<n>
4815     };
4816
4817   // Fill in the stub template look-up table.  Stub templates are constructed
4818   // per instance of Stub_factory for fast look-up without locking
4819   // in a thread-enabled environment.
4820
4821   this->stub_templates_[arm_stub_none] =
4822     new Stub_template(arm_stub_none, NULL, 0);
4823
4824 #define DEF_STUB(x)     \
4825   do \
4826     { \
4827       size_t array_size \
4828         = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4829       Stub_type type = arm_stub_##x; \
4830       this->stub_templates_[type] = \
4831         new Stub_template(type, elf32_arm_stub_##x, array_size); \
4832     } \
4833   while (0);
4834
4835   DEF_STUBS
4836 #undef DEF_STUB
4837 }
4838
4839 // Stub_table methods.
4840
4841 // Remove all Cortex-A8 stub.
4842
4843 template<bool big_endian>
4844 void
4845 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4846 {
4847   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4848        p != this->cortex_a8_stubs_.end();
4849        ++p)
4850     delete p->second;
4851   this->cortex_a8_stubs_.clear();
4852 }
4853
4854 // Relocate one stub.  This is a helper for Stub_table::relocate_stubs().
4855
4856 template<bool big_endian>
4857 void
4858 Stub_table<big_endian>::relocate_stub(
4859     Stub* stub,
4860     const Relocate_info<32, big_endian>* relinfo,
4861     Target_arm<big_endian>* arm_target,
4862     Output_section* output_section,
4863     unsigned char* view,
4864     Arm_address address,
4865     section_size_type view_size)
4866 {
4867   const Stub_template* stub_template = stub->stub_template();
4868   if (stub_template->reloc_count() != 0)
4869     {
4870       // Adjust view to cover the stub only.
4871       section_size_type offset = stub->offset();
4872       section_size_type stub_size = stub_template->size();
4873       gold_assert(offset + stub_size <= view_size);
4874
4875       arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4876                                 address + offset, stub_size);
4877     }
4878 }
4879
4880 // Relocate all stubs in this stub table.
4881
4882 template<bool big_endian>
4883 void
4884 Stub_table<big_endian>::relocate_stubs(
4885     const Relocate_info<32, big_endian>* relinfo,
4886     Target_arm<big_endian>* arm_target,
4887     Output_section* output_section,
4888     unsigned char* view,
4889     Arm_address address,
4890     section_size_type view_size)
4891 {
4892   // If we are passed a view bigger than the stub table's.  we need to
4893   // adjust the view.
4894   gold_assert(address == this->address()
4895               && (view_size
4896                   == static_cast<section_size_type>(this->data_size())));
4897
4898   // Relocate all relocation stubs.
4899   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4900       p != this->reloc_stubs_.end();
4901       ++p)
4902     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4903                         address, view_size);
4904
4905   // Relocate all Cortex-A8 stubs.
4906   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4907        p != this->cortex_a8_stubs_.end();
4908        ++p)
4909     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4910                         address, view_size);
4911
4912   // Relocate all ARM V4BX stubs.
4913   for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4914        p != this->arm_v4bx_stubs_.end();
4915        ++p)
4916     {
4917       if (*p != NULL)
4918         this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4919                             address, view_size);
4920     }
4921 }
4922
4923 // Write out the stubs to file.
4924
4925 template<bool big_endian>
4926 void
4927 Stub_table<big_endian>::do_write(Output_file* of)
4928 {
4929   off_t offset = this->offset();
4930   const section_size_type oview_size =
4931     convert_to_section_size_type(this->data_size());
4932   unsigned char* const oview = of->get_output_view(offset, oview_size);
4933
4934   // Write relocation stubs.
4935   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4936       p != this->reloc_stubs_.end();
4937       ++p)
4938     {
4939       Reloc_stub* stub = p->second;
4940       Arm_address address = this->address() + stub->offset();
4941       gold_assert(address
4942                   == align_address(address,
4943                                    stub->stub_template()->alignment()));
4944       stub->write(oview + stub->offset(), stub->stub_template()->size(),
4945                   big_endian);
4946     }
4947
4948   // Write Cortex-A8 stubs.
4949   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4950        p != this->cortex_a8_stubs_.end();
4951        ++p)
4952     {
4953       Cortex_a8_stub* stub = p->second;
4954       Arm_address address = this->address() + stub->offset();
4955       gold_assert(address
4956                   == align_address(address,
4957                                    stub->stub_template()->alignment()));
4958       stub->write(oview + stub->offset(), stub->stub_template()->size(),
4959                   big_endian);
4960     }
4961
4962   // Write ARM V4BX relocation stubs.
4963   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4964        p != this->arm_v4bx_stubs_.end();
4965        ++p)
4966     {
4967       if (*p == NULL)
4968         continue;
4969
4970       Arm_address address = this->address() + (*p)->offset();
4971       gold_assert(address
4972                   == align_address(address,
4973                                    (*p)->stub_template()->alignment()));
4974       (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4975                   big_endian);
4976     }
4977
4978   of->write_output_view(this->offset(), oview_size, oview);
4979 }
4980
4981 // Update the data size and address alignment of the stub table at the end
4982 // of a relaxation pass.   Return true if either the data size or the
4983 // alignment changed in this relaxation pass.
4984
4985 template<bool big_endian>
4986 bool
4987 Stub_table<big_endian>::update_data_size_and_addralign()
4988 {
4989   // Go over all stubs in table to compute data size and address alignment.
4990   off_t size = this->reloc_stubs_size_;
4991   unsigned addralign = this->reloc_stubs_addralign_;
4992
4993   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4994        p != this->cortex_a8_stubs_.end();
4995        ++p)
4996     {
4997       const Stub_template* stub_template = p->second->stub_template();
4998       addralign = std::max(addralign, stub_template->alignment());
4999       size = (align_address(size, stub_template->alignment())
5000               + stub_template->size());
5001     }
5002
5003   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5004        p != this->arm_v4bx_stubs_.end();
5005        ++p)
5006     {
5007       if (*p == NULL)
5008         continue;
5009
5010       const Stub_template* stub_template = (*p)->stub_template();
5011       addralign = std::max(addralign, stub_template->alignment());
5012       size = (align_address(size, stub_template->alignment())
5013               + stub_template->size());
5014     }
5015
5016   // Check if either data size or alignment changed in this pass.
5017   // Update prev_data_size_ and prev_addralign_.  These will be used
5018   // as the current data size and address alignment for the next pass.
5019   bool changed = size != this->prev_data_size_;
5020   this->prev_data_size_ = size;
5021
5022   if (addralign != this->prev_addralign_)
5023     changed = true;
5024   this->prev_addralign_ = addralign;
5025
5026   return changed;
5027 }
5028
5029 // Finalize the stubs.  This sets the offsets of the stubs within the stub
5030 // table.  It also marks all input sections needing Cortex-A8 workaround.
5031
5032 template<bool big_endian>
5033 void
5034 Stub_table<big_endian>::finalize_stubs()
5035 {
5036   off_t off = this->reloc_stubs_size_;
5037   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5038        p != this->cortex_a8_stubs_.end();
5039        ++p)
5040     {
5041       Cortex_a8_stub* stub = p->second;
5042       const Stub_template* stub_template = stub->stub_template();
5043       uint64_t stub_addralign = stub_template->alignment();
5044       off = align_address(off, stub_addralign);
5045       stub->set_offset(off);
5046       off += stub_template->size();
5047
5048       // Mark input section so that we can determine later if a code section
5049       // needs the Cortex-A8 workaround quickly.
5050       Arm_relobj<big_endian>* arm_relobj =
5051         Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5052       arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5053     }
5054
5055   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5056       p != this->arm_v4bx_stubs_.end();
5057       ++p)
5058     {
5059       if (*p == NULL)
5060         continue;
5061
5062       const Stub_template* stub_template = (*p)->stub_template();
5063       uint64_t stub_addralign = stub_template->alignment();
5064       off = align_address(off, stub_addralign);
5065       (*p)->set_offset(off);
5066       off += stub_template->size();
5067     }
5068
5069   gold_assert(off <= this->prev_data_size_);
5070 }
5071
5072 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5073 // and VIEW_ADDRESS + VIEW_SIZE - 1.  VIEW points to the mapped address
5074 // of the address range seen by the linker.
5075
5076 template<bool big_endian>
5077 void
5078 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5079     Target_arm<big_endian>* arm_target,
5080     unsigned char* view,
5081     Arm_address view_address,
5082     section_size_type view_size)
5083 {
5084   // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5085   for (Cortex_a8_stub_list::const_iterator p =
5086          this->cortex_a8_stubs_.lower_bound(view_address);
5087        ((p != this->cortex_a8_stubs_.end())
5088         && (p->first < (view_address + view_size)));
5089        ++p)
5090     {
5091       // We do not store the THUMB bit in the LSB of either the branch address
5092       // or the stub offset.  There is no need to strip the LSB.
5093       Arm_address branch_address = p->first;
5094       const Cortex_a8_stub* stub = p->second;
5095       Arm_address stub_address = this->address() + stub->offset();
5096
5097       // Offset of the branch instruction relative to this view.
5098       section_size_type offset =
5099         convert_to_section_size_type(branch_address - view_address);
5100       gold_assert((offset + 4) <= view_size);
5101
5102       arm_target->apply_cortex_a8_workaround(stub, stub_address,
5103                                              view + offset, branch_address);
5104     }
5105 }
5106
5107 // Arm_input_section methods.
5108
5109 // Initialize an Arm_input_section.
5110
5111 template<bool big_endian>
5112 void
5113 Arm_input_section<big_endian>::init()
5114 {
5115   Relobj* relobj = this->relobj();
5116   unsigned int shndx = this->shndx();
5117
5118   // We have to cache original size, alignment and contents to avoid locking
5119   // the original file.
5120   this->original_addralign_ =
5121     convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5122
5123   // This is not efficient but we expect only a small number of relaxed
5124   // input sections for stubs.
5125   section_size_type section_size;
5126   const unsigned char* section_contents =
5127     relobj->section_contents(shndx, &section_size, false);
5128   this->original_size_ =
5129     convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5130
5131   gold_assert(this->original_contents_ == NULL);
5132   this->original_contents_ = new unsigned char[section_size];
5133   memcpy(this->original_contents_, section_contents, section_size);
5134
5135   // We want to make this look like the original input section after
5136   // output sections are finalized.
5137   Output_section* os = relobj->output_section(shndx);
5138   off_t offset = relobj->output_section_offset(shndx);
5139   gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5140   this->set_address(os->address() + offset);
5141   this->set_file_offset(os->offset() + offset);
5142
5143   this->set_current_data_size(this->original_size_);
5144   this->finalize_data_size();
5145 }
5146
5147 template<bool big_endian>
5148 void
5149 Arm_input_section<big_endian>::do_write(Output_file* of)
5150 {
5151   // We have to write out the original section content.
5152   gold_assert(this->original_contents_ != NULL);
5153   of->write(this->offset(), this->original_contents_,
5154             this->original_size_);
5155
5156   // If this owns a stub table and it is not empty, write it.
5157   if (this->is_stub_table_owner() && !this->stub_table_->empty())
5158     this->stub_table_->write(of);
5159 }
5160
5161 // Finalize data size.
5162
5163 template<bool big_endian>
5164 void
5165 Arm_input_section<big_endian>::set_final_data_size()
5166 {
5167   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5168
5169   if (this->is_stub_table_owner())
5170     {
5171       this->stub_table_->finalize_data_size();
5172       off = align_address(off, this->stub_table_->addralign());
5173       off += this->stub_table_->data_size();
5174     }
5175   this->set_data_size(off);
5176 }
5177
5178 // Reset address and file offset.
5179
5180 template<bool big_endian>
5181 void
5182 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5183 {
5184   // Size of the original input section contents.
5185   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5186
5187   // If this is a stub table owner, account for the stub table size.
5188   if (this->is_stub_table_owner())
5189     {
5190       Stub_table<big_endian>* stub_table = this->stub_table_;
5191
5192       // Reset the stub table's address and file offset.  The
5193       // current data size for child will be updated after that.
5194       stub_table_->reset_address_and_file_offset();
5195       off = align_address(off, stub_table_->addralign());
5196       off += stub_table->current_data_size();
5197     }
5198
5199   this->set_current_data_size(off);
5200 }
5201
5202 // Arm_exidx_cantunwind methods.
5203
5204 // Write this to Output file OF for a fixed endianness.
5205
5206 template<bool big_endian>
5207 void
5208 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5209 {
5210   off_t offset = this->offset();
5211   const section_size_type oview_size = 8;
5212   unsigned char* const oview = of->get_output_view(offset, oview_size);
5213
5214   Output_section* os = this->relobj_->output_section(this->shndx_);
5215   gold_assert(os != NULL);
5216
5217   Arm_relobj<big_endian>* arm_relobj =
5218     Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5219   Arm_address output_offset =
5220     arm_relobj->get_output_section_offset(this->shndx_);
5221   Arm_address section_start;
5222   section_size_type section_size;
5223
5224   // Find out the end of the text section referred by this.
5225   if (output_offset != Arm_relobj<big_endian>::invalid_address)
5226     {
5227       section_start = os->address() + output_offset;
5228       const Arm_exidx_input_section* exidx_input_section =
5229         arm_relobj->exidx_input_section_by_link(this->shndx_);
5230       gold_assert(exidx_input_section != NULL);
5231       section_size =
5232         convert_to_section_size_type(exidx_input_section->text_size());
5233     }
5234   else
5235     {
5236       // Currently this only happens for a relaxed section.
5237       const Output_relaxed_input_section* poris =
5238         os->find_relaxed_input_section(this->relobj_, this->shndx_);
5239       gold_assert(poris != NULL);
5240       section_start = poris->address();
5241       section_size = convert_to_section_size_type(poris->data_size());
5242     }
5243
5244   // We always append this to the end of an EXIDX section.
5245   Arm_address output_address = section_start + section_size;
5246
5247   // Write out the entry.  The first word either points to the beginning
5248   // or after the end of a text section.  The second word is the special
5249   // EXIDX_CANTUNWIND value.
5250   uint32_t prel31_offset = output_address - this->address();
5251   if (Bits<31>::has_overflow32(offset))
5252     gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5253   elfcpp::Swap_unaligned<32, big_endian>::writeval(oview,
5254                                                    prel31_offset & 0x7fffffffU);
5255   elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4,
5256                                                    elfcpp::EXIDX_CANTUNWIND);
5257
5258   of->write_output_view(this->offset(), oview_size, oview);
5259 }
5260
5261 // Arm_exidx_merged_section methods.
5262
5263 // Constructor for Arm_exidx_merged_section.
5264 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5265 // SECTION_OFFSET_MAP points to a section offset map describing how
5266 // parts of the input section are mapped to output.  DELETED_BYTES is
5267 // the number of bytes deleted from the EXIDX input section.
5268
5269 Arm_exidx_merged_section::Arm_exidx_merged_section(
5270     const Arm_exidx_input_section& exidx_input_section,
5271     const Arm_exidx_section_offset_map& section_offset_map,
5272     uint32_t deleted_bytes)
5273   : Output_relaxed_input_section(exidx_input_section.relobj(),
5274                                  exidx_input_section.shndx(),
5275                                  exidx_input_section.addralign()),
5276     exidx_input_section_(exidx_input_section),
5277     section_offset_map_(section_offset_map)
5278 {
5279   // If we retain or discard the whole EXIDX input section,  we would
5280   // not be here.
5281   gold_assert(deleted_bytes != 0
5282               && deleted_bytes != this->exidx_input_section_.size());
5283
5284   // Fix size here so that we do not need to implement set_final_data_size.
5285   uint32_t size = exidx_input_section.size() - deleted_bytes;
5286   this->set_data_size(size);
5287   this->fix_data_size();
5288
5289   // Allocate buffer for section contents and build contents.
5290   this->section_contents_ = new unsigned char[size];
5291 }
5292
5293 // Build the contents of a merged EXIDX output section.
5294
5295 void
5296 Arm_exidx_merged_section::build_contents(
5297     const unsigned char* original_contents,
5298     section_size_type original_size)
5299 {
5300   // Go over spans of input offsets and write only those that are not
5301   // discarded.
5302   section_offset_type in_start = 0;
5303   section_offset_type out_start = 0;
5304   section_offset_type in_max =
5305     convert_types<section_offset_type>(original_size);
5306   section_offset_type out_max =
5307     convert_types<section_offset_type>(this->data_size());
5308   for (Arm_exidx_section_offset_map::const_iterator p =
5309         this->section_offset_map_.begin();
5310       p != this->section_offset_map_.end();
5311       ++p)
5312     {
5313       section_offset_type in_end = p->first;
5314       gold_assert(in_end >= in_start);
5315       section_offset_type out_end = p->second;
5316       size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5317       if (out_end != -1)
5318         {
5319           size_t out_chunk_size =
5320             convert_types<size_t>(out_end - out_start + 1);
5321
5322           gold_assert(out_chunk_size == in_chunk_size
5323                       && in_end < in_max && out_end < out_max);
5324
5325           memcpy(this->section_contents_ + out_start,
5326                  original_contents + in_start,
5327                  out_chunk_size);
5328           out_start += out_chunk_size;
5329         }
5330       in_start += in_chunk_size;
5331     }
5332 }
5333
5334 // Given an input OBJECT, an input section index SHNDX within that
5335 // object, and an OFFSET relative to the start of that input
5336 // section, return whether or not the corresponding offset within
5337 // the output section is known.  If this function returns true, it
5338 // sets *POUTPUT to the output offset.  The value -1 indicates that
5339 // this input offset is being discarded.
5340
5341 bool
5342 Arm_exidx_merged_section::do_output_offset(
5343     const Relobj* relobj,
5344     unsigned int shndx,
5345     section_offset_type offset,
5346     section_offset_type* poutput) const
5347 {
5348   // We only handle offsets for the original EXIDX input section.
5349   if (relobj != this->exidx_input_section_.relobj()
5350       || shndx != this->exidx_input_section_.shndx())
5351     return false;
5352
5353   section_offset_type section_size =
5354     convert_types<section_offset_type>(this->exidx_input_section_.size());
5355   if (offset < 0 || offset >= section_size)
5356     // Input offset is out of valid range.
5357     *poutput = -1;
5358   else
5359     {
5360       // We need to look up the section offset map to determine the output
5361       // offset.  Find the reference point in map that is first offset
5362       // bigger than or equal to this offset.
5363       Arm_exidx_section_offset_map::const_iterator p =
5364         this->section_offset_map_.lower_bound(offset);
5365
5366       // The section offset maps are build such that this should not happen if
5367       // input offset is in the valid range.
5368       gold_assert(p != this->section_offset_map_.end());
5369
5370       // We need to check if this is dropped.
5371      section_offset_type ref = p->first;
5372      section_offset_type mapped_ref = p->second;
5373
5374       if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5375         // Offset is present in output.
5376         *poutput = mapped_ref + (offset - ref);
5377       else
5378         // Offset is discarded owing to EXIDX entry merging.
5379         *poutput = -1;
5380     }
5381
5382   return true;
5383 }
5384
5385 // Write this to output file OF.
5386
5387 void
5388 Arm_exidx_merged_section::do_write(Output_file* of)
5389 {
5390   off_t offset = this->offset();
5391   const section_size_type oview_size = this->data_size();
5392   unsigned char* const oview = of->get_output_view(offset, oview_size);
5393
5394   Output_section* os = this->relobj()->output_section(this->shndx());
5395   gold_assert(os != NULL);
5396
5397   memcpy(oview, this->section_contents_, oview_size);
5398   of->write_output_view(this->offset(), oview_size, oview);
5399 }
5400
5401 // Arm_exidx_fixup methods.
5402
5403 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5404 // is not an EXIDX_CANTUNWIND entry already.  The new EXIDX_CANTUNWIND entry
5405 // points to the end of the last seen EXIDX section.
5406
5407 void
5408 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5409 {
5410   if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5411       && this->last_input_section_ != NULL)
5412     {
5413       Relobj* relobj = this->last_input_section_->relobj();
5414       unsigned int text_shndx = this->last_input_section_->link();
5415       Arm_exidx_cantunwind* cantunwind =
5416         new Arm_exidx_cantunwind(relobj, text_shndx);
5417       this->exidx_output_section_->add_output_section_data(cantunwind);
5418       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5419     }
5420 }
5421
5422 // Process an EXIDX section entry in input.  Return whether this entry
5423 // can be deleted in the output.  SECOND_WORD in the second word of the
5424 // EXIDX entry.
5425
5426 bool
5427 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5428 {
5429   bool delete_entry;
5430   if (second_word == elfcpp::EXIDX_CANTUNWIND)
5431     {
5432       // Merge if previous entry is also an EXIDX_CANTUNWIND.
5433       delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5434       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5435     }
5436   else if ((second_word & 0x80000000) != 0)
5437     {
5438       // Inlined unwinding data.  Merge if equal to previous.
5439       delete_entry = (merge_exidx_entries_
5440                       && this->last_unwind_type_ == UT_INLINED_ENTRY
5441                       && this->last_inlined_entry_ == second_word);
5442       this->last_unwind_type_ = UT_INLINED_ENTRY;
5443       this->last_inlined_entry_ = second_word;
5444     }
5445   else
5446     {
5447       // Normal table entry.  In theory we could merge these too,
5448       // but duplicate entries are likely to be much less common.
5449       delete_entry = false;
5450       this->last_unwind_type_ = UT_NORMAL_ENTRY;
5451     }
5452   return delete_entry;
5453 }
5454
5455 // Update the current section offset map during EXIDX section fix-up.
5456 // If there is no map, create one.  INPUT_OFFSET is the offset of a
5457 // reference point, DELETED_BYTES is the number of deleted by in the
5458 // section so far.  If DELETE_ENTRY is true, the reference point and
5459 // all offsets after the previous reference point are discarded.
5460
5461 void
5462 Arm_exidx_fixup::update_offset_map(
5463     section_offset_type input_offset,
5464     section_size_type deleted_bytes,
5465     bool delete_entry)
5466 {
5467   if (this->section_offset_map_ == NULL)
5468     this->section_offset_map_ = new Arm_exidx_section_offset_map();
5469   section_offset_type output_offset;
5470   if (delete_entry)
5471     output_offset = Arm_exidx_input_section::invalid_offset;
5472   else
5473     output_offset = input_offset - deleted_bytes;
5474   (*this->section_offset_map_)[input_offset] = output_offset;
5475 }
5476
5477 // Process EXIDX_INPUT_SECTION for EXIDX entry merging.  Return the number of
5478 // bytes deleted.  SECTION_CONTENTS points to the contents of the EXIDX
5479 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5480 // If some entries are merged, also store a pointer to a newly created
5481 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP.  The caller
5482 // owns the map and is responsible for releasing it after use.
5483
5484 template<bool big_endian>
5485 uint32_t
5486 Arm_exidx_fixup::process_exidx_section(
5487     const Arm_exidx_input_section* exidx_input_section,
5488     const unsigned char* section_contents,
5489     section_size_type section_size,
5490     Arm_exidx_section_offset_map** psection_offset_map)
5491 {
5492   Relobj* relobj = exidx_input_section->relobj();
5493   unsigned shndx = exidx_input_section->shndx();
5494
5495   if ((section_size % 8) != 0)
5496     {
5497       // Something is wrong with this section.  Better not touch it.
5498       gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5499                  relobj->name().c_str(), shndx);
5500       this->last_input_section_ = exidx_input_section;
5501       this->last_unwind_type_ = UT_NONE;
5502       return 0;
5503     }
5504
5505   uint32_t deleted_bytes = 0;
5506   bool prev_delete_entry = false;
5507   gold_assert(this->section_offset_map_ == NULL);
5508
5509   for (section_size_type i = 0; i < section_size; i += 8)
5510     {
5511       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5512       const Valtype* wv =
5513           reinterpret_cast<const Valtype*>(section_contents + i + 4);
5514       uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5515
5516       bool delete_entry = this->process_exidx_entry(second_word);
5517
5518       // Entry deletion causes changes in output offsets.  We use a std::map
5519       // to record these.  And entry (x, y) means input offset x
5520       // is mapped to output offset y.  If y is invalid_offset, then x is
5521       // dropped in the output.  Because of the way std::map::lower_bound
5522       // works, we record the last offset in a region w.r.t to keeping or
5523       // dropping.  If there is no entry (x0, y0) for an input offset x0,
5524       // the output offset y0 of it is determined by the output offset y1 of
5525       // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5526       // in the map.  If y1 is not -1, then y0 = y1 + x0 - x1.  Otherwise, y1
5527       // y0 is also -1.
5528       if (delete_entry != prev_delete_entry && i != 0)
5529         this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5530
5531       // Update total deleted bytes for this entry.
5532       if (delete_entry)
5533         deleted_bytes += 8;
5534
5535       prev_delete_entry = delete_entry;
5536     }
5537
5538   // If section offset map is not NULL, make an entry for the end of
5539   // section.
5540   if (this->section_offset_map_ != NULL)
5541     update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5542
5543   *psection_offset_map = this->section_offset_map_;
5544   this->section_offset_map_ = NULL;
5545   this->last_input_section_ = exidx_input_section;
5546
5547   // Set the first output text section so that we can link the EXIDX output
5548   // section to it.  Ignore any EXIDX input section that is completely merged.
5549   if (this->first_output_text_section_ == NULL
5550       && deleted_bytes != section_size)
5551     {
5552       unsigned int link = exidx_input_section->link();
5553       Output_section* os = relobj->output_section(link);
5554       gold_assert(os != NULL);
5555       this->first_output_text_section_ = os;
5556     }
5557
5558   return deleted_bytes;
5559 }
5560
5561 // Arm_output_section methods.
5562
5563 // Create a stub group for input sections from BEGIN to END.  OWNER
5564 // points to the input section to be the owner a new stub table.
5565
5566 template<bool big_endian>
5567 void
5568 Arm_output_section<big_endian>::create_stub_group(
5569   Input_section_list::const_iterator begin,
5570   Input_section_list::const_iterator end,
5571   Input_section_list::const_iterator owner,
5572   Target_arm<big_endian>* target,
5573   std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5574   const Task* task)
5575 {
5576   // We use a different kind of relaxed section in an EXIDX section.
5577   // The static casting from Output_relaxed_input_section to
5578   // Arm_input_section is invalid in an EXIDX section.  We are okay
5579   // because we should not be calling this for an EXIDX section.
5580   gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5581
5582   // Currently we convert ordinary input sections into relaxed sections only
5583   // at this point but we may want to support creating relaxed input section
5584   // very early.  So we check here to see if owner is already a relaxed
5585   // section.
5586
5587   Arm_input_section<big_endian>* arm_input_section;
5588   if (owner->is_relaxed_input_section())
5589     {
5590       arm_input_section =
5591         Arm_input_section<big_endian>::as_arm_input_section(
5592           owner->relaxed_input_section());
5593     }
5594   else
5595     {
5596       gold_assert(owner->is_input_section());
5597       // Create a new relaxed input section.  We need to lock the original
5598       // file.
5599       Task_lock_obj<Object> tl(task, owner->relobj());
5600       arm_input_section =
5601         target->new_arm_input_section(owner->relobj(), owner->shndx());
5602       new_relaxed_sections->push_back(arm_input_section);
5603     }
5604
5605   // Create a stub table.
5606   Stub_table<big_endian>* stub_table =
5607     target->new_stub_table(arm_input_section);
5608
5609   arm_input_section->set_stub_table(stub_table);
5610
5611   Input_section_list::const_iterator p = begin;
5612   Input_section_list::const_iterator prev_p;
5613
5614   // Look for input sections or relaxed input sections in [begin ... end].
5615   do
5616     {
5617       if (p->is_input_section() || p->is_relaxed_input_section())
5618         {
5619           // The stub table information for input sections live
5620           // in their objects.
5621           Arm_relobj<big_endian>* arm_relobj =
5622             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5623           arm_relobj->set_stub_table(p->shndx(), stub_table);
5624         }
5625       prev_p = p++;
5626     }
5627   while (prev_p != end);
5628 }
5629
5630 // Group input sections for stub generation.  GROUP_SIZE is roughly the limit
5631 // of stub groups.  We grow a stub group by adding input section until the
5632 // size is just below GROUP_SIZE.  The last input section will be converted
5633 // into a stub table.  If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5634 // input section after the stub table, effectively double the group size.
5635 //
5636 // This is similar to the group_sections() function in elf32-arm.c but is
5637 // implemented differently.
5638
5639 template<bool big_endian>
5640 void
5641 Arm_output_section<big_endian>::group_sections(
5642     section_size_type group_size,
5643     bool stubs_always_after_branch,
5644     Target_arm<big_endian>* target,
5645     const Task* task)
5646 {
5647   // States for grouping.
5648   typedef enum
5649   {
5650     // No group is being built.
5651     NO_GROUP,
5652     // A group is being built but the stub table is not found yet.
5653     // We keep group a stub group until the size is just under GROUP_SIZE.
5654     // The last input section in the group will be used as the stub table.
5655     FINDING_STUB_SECTION,
5656     // A group is being built and we have already found a stub table.
5657     // We enter this state to grow a stub group by adding input section
5658     // after the stub table.  This effectively doubles the group size.
5659     HAS_STUB_SECTION
5660   } State;
5661
5662   // Any newly created relaxed sections are stored here.
5663   std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5664
5665   State state = NO_GROUP;
5666   section_size_type off = 0;
5667   section_size_type group_begin_offset = 0;
5668   section_size_type group_end_offset = 0;
5669   section_size_type stub_table_end_offset = 0;
5670   Input_section_list::const_iterator group_begin =
5671     this->input_sections().end();
5672   Input_section_list::const_iterator stub_table =
5673     this->input_sections().end();
5674   Input_section_list::const_iterator group_end = this->input_sections().end();
5675   for (Input_section_list::const_iterator p = this->input_sections().begin();
5676        p != this->input_sections().end();
5677        ++p)
5678     {
5679       section_size_type section_begin_offset =
5680         align_address(off, p->addralign());
5681       section_size_type section_end_offset =
5682         section_begin_offset + p->data_size();
5683
5684       // Check to see if we should group the previously seen sections.
5685       switch (state)
5686         {
5687         case NO_GROUP:
5688           break;
5689
5690         case FINDING_STUB_SECTION:
5691           // Adding this section makes the group larger than GROUP_SIZE.
5692           if (section_end_offset - group_begin_offset >= group_size)
5693             {
5694               if (stubs_always_after_branch)
5695                 {
5696                   gold_assert(group_end != this->input_sections().end());
5697                   this->create_stub_group(group_begin, group_end, group_end,
5698                                           target, &new_relaxed_sections,
5699                                           task);
5700                   state = NO_GROUP;
5701                 }
5702               else
5703                 {
5704                   // But wait, there's more!  Input sections up to
5705                   // stub_group_size bytes after the stub table can be
5706                   // handled by it too.
5707                   state = HAS_STUB_SECTION;
5708                   stub_table = group_end;
5709                   stub_table_end_offset = group_end_offset;
5710                 }
5711             }
5712             break;
5713
5714         case HAS_STUB_SECTION:
5715           // Adding this section makes the post stub-section group larger
5716           // than GROUP_SIZE.
5717           if (section_end_offset - stub_table_end_offset >= group_size)
5718            {
5719              gold_assert(group_end != this->input_sections().end());
5720              this->create_stub_group(group_begin, group_end, stub_table,
5721                                      target, &new_relaxed_sections, task);
5722              state = NO_GROUP;
5723            }
5724            break;
5725
5726           default:
5727             gold_unreachable();
5728         }
5729
5730       // If we see an input section and currently there is no group, start
5731       // a new one.  Skip any empty sections.  We look at the data size
5732       // instead of calling p->relobj()->section_size() to avoid locking.
5733       if ((p->is_input_section() || p->is_relaxed_input_section())
5734           && (p->data_size() != 0))
5735         {
5736           if (state == NO_GROUP)
5737             {
5738               state = FINDING_STUB_SECTION;
5739               group_begin = p;
5740               group_begin_offset = section_begin_offset;
5741             }
5742
5743           // Keep track of the last input section seen.
5744           group_end = p;
5745           group_end_offset = section_end_offset;
5746         }
5747
5748       off = section_end_offset;
5749     }
5750
5751   // Create a stub group for any ungrouped sections.
5752   if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5753     {
5754       gold_assert(group_end != this->input_sections().end());
5755       this->create_stub_group(group_begin, group_end,
5756                               (state == FINDING_STUB_SECTION
5757                                ? group_end
5758                                : stub_table),
5759                                target, &new_relaxed_sections, task);
5760     }
5761
5762   // Convert input section into relaxed input section in a batch.
5763   if (!new_relaxed_sections.empty())
5764     this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5765
5766   // Update the section offsets
5767   for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5768     {
5769       Arm_relobj<big_endian>* arm_relobj =
5770         Arm_relobj<big_endian>::as_arm_relobj(
5771           new_relaxed_sections[i]->relobj());
5772       unsigned int shndx = new_relaxed_sections[i]->shndx();
5773       // Tell Arm_relobj that this input section is converted.
5774       arm_relobj->convert_input_section_to_relaxed_section(shndx);
5775     }
5776 }
5777
5778 // Append non empty text sections in this to LIST in ascending
5779 // order of their position in this.
5780
5781 template<bool big_endian>
5782 void
5783 Arm_output_section<big_endian>::append_text_sections_to_list(
5784     Text_section_list* list)
5785 {
5786   gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5787
5788   for (Input_section_list::const_iterator p = this->input_sections().begin();
5789        p != this->input_sections().end();
5790        ++p)
5791     {
5792       // We only care about plain or relaxed input sections.  We also
5793       // ignore any merged sections.
5794       if (p->is_input_section() || p->is_relaxed_input_section())
5795         list->push_back(Text_section_list::value_type(p->relobj(),
5796                                                       p->shndx()));
5797     }
5798 }
5799
5800 template<bool big_endian>
5801 void
5802 Arm_output_section<big_endian>::fix_exidx_coverage(
5803     Layout* layout,
5804     const Text_section_list& sorted_text_sections,
5805     Symbol_table* symtab,
5806     bool merge_exidx_entries,
5807     const Task* task)
5808 {
5809   // We should only do this for the EXIDX output section.
5810   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5811
5812   // We don't want the relaxation loop to undo these changes, so we discard
5813   // the current saved states and take another one after the fix-up.
5814   this->discard_states();
5815
5816   // Remove all input sections.
5817   uint64_t address = this->address();
5818   typedef std::list<Output_section::Input_section> Input_section_list;
5819   Input_section_list input_sections;
5820   this->reset_address_and_file_offset();
5821   this->get_input_sections(address, std::string(""), &input_sections);
5822
5823   if (!this->input_sections().empty())
5824     gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5825
5826   // Go through all the known input sections and record them.
5827   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5828   typedef Unordered_map<Section_id, const Output_section::Input_section*,
5829                         Section_id_hash> Text_to_exidx_map;
5830   Text_to_exidx_map text_to_exidx_map;
5831   for (Input_section_list::const_iterator p = input_sections.begin();
5832        p != input_sections.end();
5833        ++p)
5834     {
5835       // This should never happen.  At this point, we should only see
5836       // plain EXIDX input sections.
5837       gold_assert(!p->is_relaxed_input_section());
5838       text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5839     }
5840
5841   Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5842
5843   // Go over the sorted text sections.
5844   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5845   Section_id_set processed_input_sections;
5846   for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5847        p != sorted_text_sections.end();
5848        ++p)
5849     {
5850       Relobj* relobj = p->first;
5851       unsigned int shndx = p->second;
5852
5853       Arm_relobj<big_endian>* arm_relobj =
5854          Arm_relobj<big_endian>::as_arm_relobj(relobj);
5855       const Arm_exidx_input_section* exidx_input_section =
5856          arm_relobj->exidx_input_section_by_link(shndx);
5857
5858       // If this text section has no EXIDX section or if the EXIDX section
5859       // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5860       // of the last seen EXIDX section.
5861       if (exidx_input_section == NULL || exidx_input_section->has_errors())
5862         {
5863           exidx_fixup.add_exidx_cantunwind_as_needed();
5864           continue;
5865         }
5866
5867       Relobj* exidx_relobj = exidx_input_section->relobj();
5868       unsigned int exidx_shndx = exidx_input_section->shndx();
5869       Section_id sid(exidx_relobj, exidx_shndx);
5870       Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5871       if (iter == text_to_exidx_map.end())
5872         {
5873           // This is odd.  We have not seen this EXIDX input section before.
5874           // We cannot do fix-up.  If we saw a SECTIONS clause in a script,
5875           // issue a warning instead.  We assume the user knows what he
5876           // or she is doing.  Otherwise, this is an error.
5877           if (layout->script_options()->saw_sections_clause())
5878             gold_warning(_("unwinding may not work because EXIDX input section"
5879                            " %u of %s is not in EXIDX output section"),
5880                          exidx_shndx, exidx_relobj->name().c_str());
5881           else
5882             gold_error(_("unwinding may not work because EXIDX input section"
5883                          " %u of %s is not in EXIDX output section"),
5884                        exidx_shndx, exidx_relobj->name().c_str());
5885
5886           exidx_fixup.add_exidx_cantunwind_as_needed();
5887           continue;
5888         }
5889
5890       // We need to access the contents of the EXIDX section, lock the
5891       // object here.
5892       Task_lock_obj<Object> tl(task, exidx_relobj);
5893       section_size_type exidx_size;
5894       const unsigned char* exidx_contents =
5895         exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5896
5897       // Fix up coverage and append input section to output data list.
5898       Arm_exidx_section_offset_map* section_offset_map = NULL;
5899       uint32_t deleted_bytes =
5900         exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5901                                                       exidx_contents,
5902                                                       exidx_size,
5903                                                       &section_offset_map);
5904
5905       if (deleted_bytes == exidx_input_section->size())
5906         {
5907           // The whole EXIDX section got merged.  Remove it from output.
5908           gold_assert(section_offset_map == NULL);
5909           exidx_relobj->set_output_section(exidx_shndx, NULL);
5910
5911           // All local symbols defined in this input section will be dropped.
5912           // We need to adjust output local symbol count.
5913           arm_relobj->set_output_local_symbol_count_needs_update();
5914         }
5915       else if (deleted_bytes > 0)
5916         {
5917           // Some entries are merged.  We need to convert this EXIDX input
5918           // section into a relaxed section.
5919           gold_assert(section_offset_map != NULL);
5920
5921           Arm_exidx_merged_section* merged_section =
5922             new Arm_exidx_merged_section(*exidx_input_section,
5923                                          *section_offset_map, deleted_bytes);
5924           merged_section->build_contents(exidx_contents, exidx_size);
5925
5926           const std::string secname = exidx_relobj->section_name(exidx_shndx);
5927           this->add_relaxed_input_section(layout, merged_section, secname);
5928           arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5929
5930           // All local symbols defined in discarded portions of this input
5931           // section will be dropped.  We need to adjust output local symbol
5932           // count.
5933           arm_relobj->set_output_local_symbol_count_needs_update();
5934         }
5935       else
5936         {
5937           // Just add back the EXIDX input section.
5938           gold_assert(section_offset_map == NULL);
5939           const Output_section::Input_section* pis = iter->second;
5940           gold_assert(pis->is_input_section());
5941           this->add_script_input_section(*pis);
5942         }
5943
5944       processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5945     }
5946
5947   // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5948   exidx_fixup.add_exidx_cantunwind_as_needed();
5949
5950   // Remove any known EXIDX input sections that are not processed.
5951   for (Input_section_list::const_iterator p = input_sections.begin();
5952        p != input_sections.end();
5953        ++p)
5954     {
5955       if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5956           == processed_input_sections.end())
5957         {
5958           // We discard a known EXIDX section because its linked
5959           // text section has been folded by ICF.  We also discard an
5960           // EXIDX section with error, the output does not matter in this
5961           // case.  We do this to avoid triggering asserts.
5962           Arm_relobj<big_endian>* arm_relobj =
5963             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5964           const Arm_exidx_input_section* exidx_input_section =
5965             arm_relobj->exidx_input_section_by_shndx(p->shndx());
5966           gold_assert(exidx_input_section != NULL);
5967           if (!exidx_input_section->has_errors())
5968             {
5969               unsigned int text_shndx = exidx_input_section->link();
5970               gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5971             }
5972
5973           // Remove this from link.  We also need to recount the
5974           // local symbols.
5975           p->relobj()->set_output_section(p->shndx(), NULL);
5976           arm_relobj->set_output_local_symbol_count_needs_update();
5977         }
5978     }
5979
5980   // Link exidx output section to the first seen output section and
5981   // set correct entry size.
5982   this->set_link_section(exidx_fixup.first_output_text_section());
5983   this->set_entsize(8);
5984
5985   // Make changes permanent.
5986   this->save_states();
5987   this->set_section_offsets_need_adjustment();
5988 }
5989
5990 // Link EXIDX output sections to text output sections.
5991
5992 template<bool big_endian>
5993 void
5994 Arm_output_section<big_endian>::set_exidx_section_link()
5995 {
5996   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5997   if (!this->input_sections().empty())
5998     {
5999       Input_section_list::const_iterator p = this->input_sections().begin();
6000       Arm_relobj<big_endian>* arm_relobj =
6001         Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6002       unsigned exidx_shndx = p->shndx();
6003       const Arm_exidx_input_section* exidx_input_section =
6004         arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6005       gold_assert(exidx_input_section != NULL);
6006       unsigned int text_shndx = exidx_input_section->link();
6007       Output_section* os = arm_relobj->output_section(text_shndx);
6008       this->set_link_section(os);
6009     }
6010 }
6011
6012 // Arm_relobj methods.
6013
6014 // Determine if an input section is scannable for stub processing.  SHDR is
6015 // the header of the section and SHNDX is the section index.  OS is the output
6016 // section for the input section and SYMTAB is the global symbol table used to
6017 // look up ICF information.
6018
6019 template<bool big_endian>
6020 bool
6021 Arm_relobj<big_endian>::section_is_scannable(
6022     const elfcpp::Shdr<32, big_endian>& shdr,
6023     unsigned int shndx,
6024     const Output_section* os,
6025     const Symbol_table* symtab)
6026 {
6027   // Skip any empty sections, unallocated sections or sections whose
6028   // type are not SHT_PROGBITS.
6029   if (shdr.get_sh_size() == 0
6030       || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6031       || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6032     return false;
6033
6034   // Skip any discarded or ICF'ed sections.
6035   if (os == NULL || symtab->is_section_folded(this, shndx))
6036     return false;
6037
6038   // If this requires special offset handling, check to see if it is
6039   // a relaxed section.  If this is not, then it is a merged section that
6040   // we cannot handle.
6041   if (this->is_output_section_offset_invalid(shndx))
6042     {
6043       const Output_relaxed_input_section* poris =
6044         os->find_relaxed_input_section(this, shndx);
6045       if (poris == NULL)
6046         return false;
6047     }
6048
6049   return true;
6050 }
6051
6052 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6053 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6054
6055 template<bool big_endian>
6056 bool
6057 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6058     const elfcpp::Shdr<32, big_endian>& shdr,
6059     const Relobj::Output_sections& out_sections,
6060     const Symbol_table* symtab,
6061     const unsigned char* pshdrs)
6062 {
6063   unsigned int sh_type = shdr.get_sh_type();
6064   if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6065     return false;
6066
6067   // Ignore empty section.
6068   off_t sh_size = shdr.get_sh_size();
6069   if (sh_size == 0)
6070     return false;
6071
6072   // Ignore reloc section with unexpected symbol table.  The
6073   // error will be reported in the final link.
6074   if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6075     return false;
6076
6077   unsigned int reloc_size;
6078   if (sh_type == elfcpp::SHT_REL)
6079     reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6080   else
6081     reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6082
6083   // Ignore reloc section with unexpected entsize or uneven size.
6084   // The error will be reported in the final link.
6085   if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6086     return false;
6087
6088   // Ignore reloc section with bad info.  This error will be
6089   // reported in the final link.
6090   unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6091   if (index >= this->shnum())
6092     return false;
6093
6094   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6095   const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6096   return this->section_is_scannable(text_shdr, index,
6097                                    out_sections[index], symtab);
6098 }
6099
6100 // Return the output address of either a plain input section or a relaxed
6101 // input section.  SHNDX is the section index.  We define and use this
6102 // instead of calling Output_section::output_address because that is slow
6103 // for large output.
6104
6105 template<bool big_endian>
6106 Arm_address
6107 Arm_relobj<big_endian>::simple_input_section_output_address(
6108     unsigned int shndx,
6109     Output_section* os)
6110 {
6111   if (this->is_output_section_offset_invalid(shndx))
6112     {
6113       const Output_relaxed_input_section* poris =
6114         os->find_relaxed_input_section(this, shndx);
6115       // We do not handle merged sections here.
6116       gold_assert(poris != NULL);
6117       return poris->address();
6118     }
6119   else
6120     return os->address() + this->get_output_section_offset(shndx);
6121 }
6122
6123 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6124 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6125
6126 template<bool big_endian>
6127 bool
6128 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6129     const elfcpp::Shdr<32, big_endian>& shdr,
6130     unsigned int shndx,
6131     Output_section* os,
6132     const Symbol_table* symtab)
6133 {
6134   if (!this->section_is_scannable(shdr, shndx, os, symtab))
6135     return false;
6136
6137   // If the section does not cross any 4K-boundaries, it does not need to
6138   // be scanned.
6139   Arm_address address = this->simple_input_section_output_address(shndx, os);
6140   if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6141     return false;
6142
6143   return true;
6144 }
6145
6146 // Scan a section for Cortex-A8 workaround.
6147
6148 template<bool big_endian>
6149 void
6150 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6151     const elfcpp::Shdr<32, big_endian>& shdr,
6152     unsigned int shndx,
6153     Output_section* os,
6154     Target_arm<big_endian>* arm_target)
6155 {
6156   // Look for the first mapping symbol in this section.  It should be
6157   // at (shndx, 0).
6158   Mapping_symbol_position section_start(shndx, 0);
6159   typename Mapping_symbols_info::const_iterator p =
6160     this->mapping_symbols_info_.lower_bound(section_start);
6161
6162   // There are no mapping symbols for this section.  Treat it as a data-only
6163   // section.  Issue a warning if section is marked as containing
6164   // instructions.
6165   if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6166     {
6167       if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6168         gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6169                        "erratum because it has no mapping symbols."),
6170                      shndx, this->name().c_str());
6171       return;
6172     }
6173
6174   Arm_address output_address =
6175     this->simple_input_section_output_address(shndx, os);
6176
6177   // Get the section contents.
6178   section_size_type input_view_size = 0;
6179   const unsigned char* input_view =
6180     this->section_contents(shndx, &input_view_size, false);
6181
6182   // We need to go through the mapping symbols to determine what to
6183   // scan.  There are two reasons.  First, we should look at THUMB code and
6184   // THUMB code only.  Second, we only want to look at the 4K-page boundary
6185   // to speed up the scanning.
6186
6187   while (p != this->mapping_symbols_info_.end()
6188         && p->first.first == shndx)
6189     {
6190       typename Mapping_symbols_info::const_iterator next =
6191         this->mapping_symbols_info_.upper_bound(p->first);
6192
6193       // Only scan part of a section with THUMB code.
6194       if (p->second == 't')
6195         {
6196           // Determine the end of this range.
6197           section_size_type span_start =
6198             convert_to_section_size_type(p->first.second);
6199           section_size_type span_end;
6200           if (next != this->mapping_symbols_info_.end()
6201               && next->first.first == shndx)
6202             span_end = convert_to_section_size_type(next->first.second);
6203           else
6204             span_end = convert_to_section_size_type(shdr.get_sh_size());
6205
6206           if (((span_start + output_address) & ~0xfffUL)
6207               != ((span_end + output_address - 1) & ~0xfffUL))
6208             {
6209               arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6210                                                           span_start, span_end,
6211                                                           input_view,
6212                                                           output_address);
6213             }
6214         }
6215
6216       p = next;
6217     }
6218 }
6219
6220 // Scan relocations for stub generation.
6221
6222 template<bool big_endian>
6223 void
6224 Arm_relobj<big_endian>::scan_sections_for_stubs(
6225     Target_arm<big_endian>* arm_target,
6226     const Symbol_table* symtab,
6227     const Layout* layout)
6228 {
6229   unsigned int shnum = this->shnum();
6230   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6231
6232   // Read the section headers.
6233   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6234                                                shnum * shdr_size,
6235                                                true, true);
6236
6237   // To speed up processing, we set up hash tables for fast lookup of
6238   // input offsets to output addresses.
6239   this->initialize_input_to_output_maps();
6240
6241   const Relobj::Output_sections& out_sections(this->output_sections());
6242
6243   Relocate_info<32, big_endian> relinfo;
6244   relinfo.symtab = symtab;
6245   relinfo.layout = layout;
6246   relinfo.object = this;
6247
6248   // Do relocation stubs scanning.
6249   const unsigned char* p = pshdrs + shdr_size;
6250   for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6251     {
6252       const elfcpp::Shdr<32, big_endian> shdr(p);
6253       if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6254                                                   pshdrs))
6255         {
6256           unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6257           Arm_address output_offset = this->get_output_section_offset(index);
6258           Arm_address output_address;
6259           if (output_offset != invalid_address)
6260             output_address = out_sections[index]->address() + output_offset;
6261           else
6262             {
6263               // Currently this only happens for a relaxed section.
6264               const Output_relaxed_input_section* poris =
6265               out_sections[index]->find_relaxed_input_section(this, index);
6266               gold_assert(poris != NULL);
6267               output_address = poris->address();
6268             }
6269
6270           // Get the relocations.
6271           const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6272                                                         shdr.get_sh_size(),
6273                                                         true, false);
6274
6275           // Get the section contents.  This does work for the case in which
6276           // we modify the contents of an input section.  We need to pass the
6277           // output view under such circumstances.
6278           section_size_type input_view_size = 0;
6279           const unsigned char* input_view =
6280             this->section_contents(index, &input_view_size, false);
6281
6282           relinfo.reloc_shndx = i;
6283           relinfo.data_shndx = index;
6284           unsigned int sh_type = shdr.get_sh_type();
6285           unsigned int reloc_size;
6286           if (sh_type == elfcpp::SHT_REL)
6287             reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6288           else
6289             reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6290
6291           Output_section* os = out_sections[index];
6292           arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6293                                              shdr.get_sh_size() / reloc_size,
6294                                              os,
6295                                              output_offset == invalid_address,
6296                                              input_view, output_address,
6297                                              input_view_size);
6298         }
6299     }
6300
6301   // Do Cortex-A8 erratum stubs scanning.  This has to be done for a section
6302   // after its relocation section, if there is one, is processed for
6303   // relocation stubs.  Merging this loop with the one above would have been
6304   // complicated since we would have had to make sure that relocation stub
6305   // scanning is done first.
6306   if (arm_target->fix_cortex_a8())
6307     {
6308       const unsigned char* p = pshdrs + shdr_size;
6309       for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6310         {
6311           const elfcpp::Shdr<32, big_endian> shdr(p);
6312           if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6313                                                           out_sections[i],
6314                                                           symtab))
6315             this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6316                                                      arm_target);
6317         }
6318     }
6319
6320   // After we've done the relocations, we release the hash tables,
6321   // since we no longer need them.
6322   this->free_input_to_output_maps();
6323 }
6324
6325 // Count the local symbols.  The ARM backend needs to know if a symbol
6326 // is a THUMB function or not.  For global symbols, it is easy because
6327 // the Symbol object keeps the ELF symbol type.  For local symbol it is
6328 // harder because we cannot access this information.   So we override the
6329 // do_count_local_symbol in parent and scan local symbols to mark
6330 // THUMB functions.  This is not the most efficient way but I do not want to
6331 // slow down other ports by calling a per symbol target hook inside
6332 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6333
6334 template<bool big_endian>
6335 void
6336 Arm_relobj<big_endian>::do_count_local_symbols(
6337     Stringpool_template<char>* pool,
6338     Stringpool_template<char>* dynpool)
6339 {
6340   // We need to fix-up the values of any local symbols whose type are
6341   // STT_ARM_TFUNC.
6342
6343   // Ask parent to count the local symbols.
6344   Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6345   const unsigned int loccount = this->local_symbol_count();
6346   if (loccount == 0)
6347     return;
6348
6349   // Initialize the thumb function bit-vector.
6350   std::vector<bool> empty_vector(loccount, false);
6351   this->local_symbol_is_thumb_function_.swap(empty_vector);
6352
6353   // Read the symbol table section header.
6354   const unsigned int symtab_shndx = this->symtab_shndx();
6355   elfcpp::Shdr<32, big_endian>
6356       symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6357   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6358
6359   // Read the local symbols.
6360   const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6361   gold_assert(loccount == symtabshdr.get_sh_info());
6362   off_t locsize = loccount * sym_size;
6363   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6364                                               locsize, true, true);
6365
6366   // For mapping symbol processing, we need to read the symbol names.
6367   unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6368   if (strtab_shndx >= this->shnum())
6369     {
6370       this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6371       return;
6372     }
6373
6374   elfcpp::Shdr<32, big_endian>
6375     strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6376   if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6377     {
6378       this->error(_("symbol table name section has wrong type: %u"),
6379                   static_cast<unsigned int>(strtabshdr.get_sh_type()));
6380       return;
6381     }
6382   const char* pnames =
6383     reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6384                                                  strtabshdr.get_sh_size(),
6385                                                  false, false));
6386
6387   // Loop over the local symbols and mark any local symbols pointing
6388   // to THUMB functions.
6389
6390   // Skip the first dummy symbol.
6391   psyms += sym_size;
6392   typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6393     this->local_values();
6394   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6395     {
6396       elfcpp::Sym<32, big_endian> sym(psyms);
6397       elfcpp::STT st_type = sym.get_st_type();
6398       Symbol_value<32>& lv((*plocal_values)[i]);
6399       Arm_address input_value = lv.input_value();
6400
6401       // Check to see if this is a mapping symbol.
6402       const char* sym_name = pnames + sym.get_st_name();
6403       if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6404         {
6405           bool is_ordinary;
6406           unsigned int input_shndx =
6407             this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6408           gold_assert(is_ordinary);
6409
6410           // Strip of LSB in case this is a THUMB symbol.
6411           Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6412           this->mapping_symbols_info_[msp] = sym_name[1];
6413         }
6414
6415       if (st_type == elfcpp::STT_ARM_TFUNC
6416           || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6417         {
6418           // This is a THUMB function.  Mark this and canonicalize the
6419           // symbol value by setting LSB.
6420           this->local_symbol_is_thumb_function_[i] = true;
6421           if ((input_value & 1) == 0)
6422             lv.set_input_value(input_value | 1);
6423         }
6424     }
6425 }
6426
6427 // Relocate sections.
6428 template<bool big_endian>
6429 void
6430 Arm_relobj<big_endian>::do_relocate_sections(
6431     const Symbol_table* symtab,
6432     const Layout* layout,
6433     const unsigned char* pshdrs,
6434     Output_file* of,
6435     typename Sized_relobj_file<32, big_endian>::Views* pviews)
6436 {
6437   // Call parent to relocate sections.
6438   Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6439                                                           pshdrs, of, pviews);
6440
6441   // We do not generate stubs if doing a relocatable link.
6442   if (parameters->options().relocatable())
6443     return;
6444
6445   // Relocate stub tables.
6446   unsigned int shnum = this->shnum();
6447
6448   Target_arm<big_endian>* arm_target =
6449     Target_arm<big_endian>::default_target();
6450
6451   Relocate_info<32, big_endian> relinfo;
6452   relinfo.symtab = symtab;
6453   relinfo.layout = layout;
6454   relinfo.object = this;
6455
6456   for (unsigned int i = 1; i < shnum; ++i)
6457     {
6458       Arm_input_section<big_endian>* arm_input_section =
6459         arm_target->find_arm_input_section(this, i);
6460
6461       if (arm_input_section != NULL
6462           && arm_input_section->is_stub_table_owner()
6463           && !arm_input_section->stub_table()->empty())
6464         {
6465           // We cannot discard a section if it owns a stub table.
6466           Output_section* os = this->output_section(i);
6467           gold_assert(os != NULL);
6468
6469           relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6470           relinfo.reloc_shdr = NULL;
6471           relinfo.data_shndx = i;
6472           relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6473
6474           gold_assert((*pviews)[i].view != NULL);
6475
6476           // We are passed the output section view.  Adjust it to cover the
6477           // stub table only.
6478           Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6479           gold_assert((stub_table->address() >= (*pviews)[i].address)
6480                       && ((stub_table->address() + stub_table->data_size())
6481                           <= (*pviews)[i].address + (*pviews)[i].view_size));
6482
6483           off_t offset = stub_table->address() - (*pviews)[i].address;
6484           unsigned char* view = (*pviews)[i].view + offset;
6485           Arm_address address = stub_table->address();
6486           section_size_type view_size = stub_table->data_size();
6487
6488           stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6489                                      view_size);
6490         }
6491
6492       // Apply Cortex A8 workaround if applicable.
6493       if (this->section_has_cortex_a8_workaround(i))
6494         {
6495           unsigned char* view = (*pviews)[i].view;
6496           Arm_address view_address = (*pviews)[i].address;
6497           section_size_type view_size = (*pviews)[i].view_size;
6498           Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6499
6500           // Adjust view to cover section.
6501           Output_section* os = this->output_section(i);
6502           gold_assert(os != NULL);
6503           Arm_address section_address =
6504             this->simple_input_section_output_address(i, os);
6505           uint64_t section_size = this->section_size(i);
6506
6507           gold_assert(section_address >= view_address
6508                       && ((section_address + section_size)
6509                           <= (view_address + view_size)));
6510
6511           unsigned char* section_view = view + (section_address - view_address);
6512
6513           // Apply the Cortex-A8 workaround to the output address range
6514           // corresponding to this input section.
6515           stub_table->apply_cortex_a8_workaround_to_address_range(
6516               arm_target,
6517               section_view,
6518               section_address,
6519               section_size);
6520         }
6521     }
6522 }
6523
6524 // Find the linked text section of an EXIDX section by looking at the first
6525 // relocation.  4.4.1 of the EHABI specifications says that an EXIDX section
6526 // must be linked to its associated code section via the sh_link field of
6527 // its section header.  However, some tools are broken and the link is not
6528 // always set.  LD just drops such an EXIDX section silently, causing the
6529 // associated code not unwindabled.   Here we try a little bit harder to
6530 // discover the linked code section.
6531 //
6532 // PSHDR points to the section header of a relocation section of an EXIDX
6533 // section.  If we can find a linked text section, return true and
6534 // store the text section index in the location PSHNDX.  Otherwise
6535 // return false.
6536
6537 template<bool big_endian>
6538 bool
6539 Arm_relobj<big_endian>::find_linked_text_section(
6540     const unsigned char* pshdr,
6541     const unsigned char* psyms,
6542     unsigned int* pshndx)
6543 {
6544   elfcpp::Shdr<32, big_endian> shdr(pshdr);
6545
6546   // If there is no relocation, we cannot find the linked text section.
6547   size_t reloc_size;
6548   if (shdr.get_sh_type() == elfcpp::SHT_REL)
6549       reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6550   else
6551       reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6552   size_t reloc_count = shdr.get_sh_size() / reloc_size;
6553
6554   // Get the relocations.
6555   const unsigned char* prelocs =
6556       this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6557
6558   // Find the REL31 relocation for the first word of the first EXIDX entry.
6559   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6560     {
6561       Arm_address r_offset;
6562       typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6563       if (shdr.get_sh_type() == elfcpp::SHT_REL)
6564         {
6565           typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6566           r_info = reloc.get_r_info();
6567           r_offset = reloc.get_r_offset();
6568         }
6569       else
6570         {
6571           typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6572           r_info = reloc.get_r_info();
6573           r_offset = reloc.get_r_offset();
6574         }
6575
6576       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6577       if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6578         continue;
6579
6580       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6581       if (r_sym == 0
6582           || r_sym >= this->local_symbol_count()
6583           || r_offset != 0)
6584         continue;
6585
6586       // This is the relocation for the first word of the first EXIDX entry.
6587       // We expect to see a local section symbol.
6588       const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6589       elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6590       if (sym.get_st_type() == elfcpp::STT_SECTION)
6591         {
6592           bool is_ordinary;
6593           *pshndx =
6594             this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6595           gold_assert(is_ordinary);
6596           return true;
6597         }
6598       else
6599         return false;
6600     }
6601
6602   return false;
6603 }
6604
6605 // Make an EXIDX input section object for an EXIDX section whose index is
6606 // SHNDX.  SHDR is the section header of the EXIDX section and TEXT_SHNDX
6607 // is the section index of the linked text section.
6608
6609 template<bool big_endian>
6610 void
6611 Arm_relobj<big_endian>::make_exidx_input_section(
6612     unsigned int shndx,
6613     const elfcpp::Shdr<32, big_endian>& shdr,
6614     unsigned int text_shndx,
6615     const elfcpp::Shdr<32, big_endian>& text_shdr)
6616 {
6617   // Create an Arm_exidx_input_section object for this EXIDX section.
6618   Arm_exidx_input_section* exidx_input_section =
6619     new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6620                                 shdr.get_sh_addralign(),
6621                                 text_shdr.get_sh_size());
6622
6623   gold_assert(this->exidx_section_map_[shndx] == NULL);
6624   this->exidx_section_map_[shndx] = exidx_input_section;
6625
6626   if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6627     {
6628       gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6629                  this->section_name(shndx).c_str(), shndx, text_shndx,
6630                  this->name().c_str());
6631       exidx_input_section->set_has_errors();
6632     }
6633   else if (this->exidx_section_map_[text_shndx] != NULL)
6634     {
6635       unsigned other_exidx_shndx =
6636         this->exidx_section_map_[text_shndx]->shndx();
6637       gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6638                    "%s(%u) in %s"),
6639                  this->section_name(shndx).c_str(), shndx,
6640                  this->section_name(other_exidx_shndx).c_str(),
6641                  other_exidx_shndx, this->section_name(text_shndx).c_str(),
6642                  text_shndx, this->name().c_str());
6643       exidx_input_section->set_has_errors();
6644     }
6645   else
6646      this->exidx_section_map_[text_shndx] = exidx_input_section;
6647
6648   // Check section flags of text section.
6649   if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6650     {
6651       gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6652                    " in %s"),
6653                  this->section_name(shndx).c_str(), shndx,
6654                  this->section_name(text_shndx).c_str(), text_shndx,
6655                  this->name().c_str());
6656       exidx_input_section->set_has_errors();
6657     }
6658   else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6659     // I would like to make this an error but currently ld just ignores
6660     // this.
6661     gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6662                    "%s(%u) in %s"),
6663                  this->section_name(shndx).c_str(), shndx,
6664                  this->section_name(text_shndx).c_str(), text_shndx,
6665                  this->name().c_str());
6666 }
6667
6668 // Read the symbol information.
6669
6670 template<bool big_endian>
6671 void
6672 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6673 {
6674   // Call parent class to read symbol information.
6675   Sized_relobj_file<32, big_endian>::do_read_symbols(sd);
6676
6677   // If this input file is a binary file, it has no processor
6678   // specific flags and attributes section.
6679   Input_file::Format format = this->input_file()->format();
6680   if (format != Input_file::FORMAT_ELF)
6681     {
6682       gold_assert(format == Input_file::FORMAT_BINARY);
6683       this->merge_flags_and_attributes_ = false;
6684       return;
6685     }
6686
6687   // Read processor-specific flags in ELF file header.
6688   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6689                                               elfcpp::Elf_sizes<32>::ehdr_size,
6690                                               true, false);
6691   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6692   this->processor_specific_flags_ = ehdr.get_e_flags();
6693
6694   // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6695   // sections.
6696   std::vector<unsigned int> deferred_exidx_sections;
6697   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6698   const unsigned char* pshdrs = sd->section_headers->data();
6699   const unsigned char* ps = pshdrs + shdr_size;
6700   bool must_merge_flags_and_attributes = false;
6701   for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6702     {
6703       elfcpp::Shdr<32, big_endian> shdr(ps);
6704
6705       // Sometimes an object has no contents except the section name string
6706       // table and an empty symbol table with the undefined symbol.  We
6707       // don't want to merge processor-specific flags from such an object.
6708       if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6709         {
6710           // Symbol table is not empty.
6711           const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6712              elfcpp::Elf_sizes<32>::sym_size;
6713           if (shdr.get_sh_size() > sym_size)
6714             must_merge_flags_and_attributes = true;
6715         }
6716       else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6717         // If this is neither an empty symbol table nor a string table,
6718         // be conservative.
6719         must_merge_flags_and_attributes = true;
6720
6721       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6722         {
6723           gold_assert(this->attributes_section_data_ == NULL);
6724           section_offset_type section_offset = shdr.get_sh_offset();
6725           section_size_type section_size =
6726             convert_to_section_size_type(shdr.get_sh_size());
6727           const unsigned char* view =
6728              this->get_view(section_offset, section_size, true, false);
6729           this->attributes_section_data_ =
6730             new Attributes_section_data(view, section_size);
6731         }
6732       else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6733         {
6734           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6735           if (text_shndx == elfcpp::SHN_UNDEF)
6736             deferred_exidx_sections.push_back(i);
6737           else
6738             {
6739               elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6740                                                      + text_shndx * shdr_size);
6741               this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6742             }
6743           // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6744           if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6745             gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6746                          this->section_name(i).c_str(), this->name().c_str());
6747         }
6748     }
6749
6750   // This is rare.
6751   if (!must_merge_flags_and_attributes)
6752     {
6753       gold_assert(deferred_exidx_sections.empty());
6754       this->merge_flags_and_attributes_ = false;
6755       return;
6756     }
6757
6758   // Some tools are broken and they do not set the link of EXIDX sections.
6759   // We look at the first relocation to figure out the linked sections.
6760   if (!deferred_exidx_sections.empty())
6761     {
6762       // We need to go over the section headers again to find the mapping
6763       // from sections being relocated to their relocation sections.  This is
6764       // a bit inefficient as we could do that in the loop above.  However,
6765       // we do not expect any deferred EXIDX sections normally.  So we do not
6766       // want to slow down the most common path.
6767       typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6768       Reloc_map reloc_map;
6769       ps = pshdrs + shdr_size;
6770       for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6771         {
6772           elfcpp::Shdr<32, big_endian> shdr(ps);
6773           elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6774           if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6775             {
6776               unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6777               if (info_shndx >= this->shnum())
6778                 gold_error(_("relocation section %u has invalid info %u"),
6779                            i, info_shndx);
6780               Reloc_map::value_type value(info_shndx, i);
6781               std::pair<Reloc_map::iterator, bool> result =
6782                 reloc_map.insert(value);
6783               if (!result.second)
6784                 gold_error(_("section %u has multiple relocation sections "
6785                              "%u and %u"),
6786                            info_shndx, i, reloc_map[info_shndx]);
6787             }
6788         }
6789
6790       // Read the symbol table section header.
6791       const unsigned int symtab_shndx = this->symtab_shndx();
6792       elfcpp::Shdr<32, big_endian>
6793           symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6794       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6795
6796       // Read the local symbols.
6797       const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6798       const unsigned int loccount = this->local_symbol_count();
6799       gold_assert(loccount == symtabshdr.get_sh_info());
6800       off_t locsize = loccount * sym_size;
6801       const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6802                                                   locsize, true, true);
6803
6804       // Process the deferred EXIDX sections.
6805       for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6806         {
6807           unsigned int shndx = deferred_exidx_sections[i];
6808           elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6809           unsigned int text_shndx = elfcpp::SHN_UNDEF;
6810           Reloc_map::const_iterator it = reloc_map.find(shndx);
6811           if (it != reloc_map.end())
6812             find_linked_text_section(pshdrs + it->second * shdr_size,
6813                                      psyms, &text_shndx);
6814           elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6815                                                  + text_shndx * shdr_size);
6816           this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6817         }
6818     }
6819 }
6820
6821 // Process relocations for garbage collection.  The ARM target uses .ARM.exidx
6822 // sections for unwinding.  These sections are referenced implicitly by
6823 // text sections linked in the section headers.  If we ignore these implicit
6824 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6825 // will be garbage-collected incorrectly.  Hence we override the same function
6826 // in the base class to handle these implicit references.
6827
6828 template<bool big_endian>
6829 void
6830 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6831                                              Layout* layout,
6832                                              Read_relocs_data* rd)
6833 {
6834   // First, call base class method to process relocations in this object.
6835   Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6836
6837   // If --gc-sections is not specified, there is nothing more to do.
6838   // This happens when --icf is used but --gc-sections is not.
6839   if (!parameters->options().gc_sections())
6840     return;
6841
6842   unsigned int shnum = this->shnum();
6843   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6844   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6845                                                shnum * shdr_size,
6846                                                true, true);
6847
6848   // Scan section headers for sections of type SHT_ARM_EXIDX.  Add references
6849   // to these from the linked text sections.
6850   const unsigned char* ps = pshdrs + shdr_size;
6851   for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6852     {
6853       elfcpp::Shdr<32, big_endian> shdr(ps);
6854       if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6855         {
6856           // Found an .ARM.exidx section, add it to the set of reachable
6857           // sections from its linked text section.
6858           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6859           symtab->gc()->add_reference(this, text_shndx, this, i);
6860         }
6861     }
6862 }
6863
6864 // Update output local symbol count.  Owing to EXIDX entry merging, some local
6865 // symbols  will be removed in output.  Adjust output local symbol count
6866 // accordingly.  We can only changed the static output local symbol count.  It
6867 // is too late to change the dynamic symbols.
6868
6869 template<bool big_endian>
6870 void
6871 Arm_relobj<big_endian>::update_output_local_symbol_count()
6872 {
6873   // Caller should check that this needs updating.  We want caller checking
6874   // because output_local_symbol_count_needs_update() is most likely inlined.
6875   gold_assert(this->output_local_symbol_count_needs_update_);
6876
6877   gold_assert(this->symtab_shndx() != -1U);
6878   if (this->symtab_shndx() == 0)
6879     {
6880       // This object has no symbols.  Weird but legal.
6881       return;
6882     }
6883
6884   // Read the symbol table section header.
6885   const unsigned int symtab_shndx = this->symtab_shndx();
6886   elfcpp::Shdr<32, big_endian>
6887     symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6888   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6889
6890   // Read the local symbols.
6891   const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6892   const unsigned int loccount = this->local_symbol_count();
6893   gold_assert(loccount == symtabshdr.get_sh_info());
6894   off_t locsize = loccount * sym_size;
6895   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6896                                               locsize, true, true);
6897
6898   // Loop over the local symbols.
6899
6900   typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6901      Output_sections;
6902   const Output_sections& out_sections(this->output_sections());
6903   unsigned int shnum = this->shnum();
6904   unsigned int count = 0;
6905   // Skip the first, dummy, symbol.
6906   psyms += sym_size;
6907   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6908     {
6909       elfcpp::Sym<32, big_endian> sym(psyms);
6910
6911       Symbol_value<32>& lv((*this->local_values())[i]);
6912
6913       // This local symbol was already discarded by do_count_local_symbols.
6914       if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6915         continue;
6916
6917       bool is_ordinary;
6918       unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6919                                                   &is_ordinary);
6920
6921       if (shndx < shnum)
6922         {
6923           Output_section* os = out_sections[shndx];
6924
6925           // This local symbol no longer has an output section.  Discard it.
6926           if (os == NULL)
6927             {
6928               lv.set_no_output_symtab_entry();
6929               continue;
6930             }
6931
6932           // Currently we only discard parts of EXIDX input sections.
6933           // We explicitly check for a merged EXIDX input section to avoid
6934           // calling Output_section_data::output_offset unless necessary.
6935           if ((this->get_output_section_offset(shndx) == invalid_address)
6936               && (this->exidx_input_section_by_shndx(shndx) != NULL))
6937             {
6938               section_offset_type output_offset =
6939                 os->output_offset(this, shndx, lv.input_value());
6940               if (output_offset == -1)
6941                 {
6942                   // This symbol is defined in a part of an EXIDX input section
6943                   // that is discarded due to entry merging.
6944                   lv.set_no_output_symtab_entry();
6945                   continue;
6946                 }
6947             }
6948         }
6949
6950       ++count;
6951     }
6952
6953   this->set_output_local_symbol_count(count);
6954   this->output_local_symbol_count_needs_update_ = false;
6955 }
6956
6957 // Arm_dynobj methods.
6958
6959 // Read the symbol information.
6960
6961 template<bool big_endian>
6962 void
6963 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6964 {
6965   // Call parent class to read symbol information.
6966   Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6967
6968   // Read processor-specific flags in ELF file header.
6969   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6970                                               elfcpp::Elf_sizes<32>::ehdr_size,
6971                                               true, false);
6972   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6973   this->processor_specific_flags_ = ehdr.get_e_flags();
6974
6975   // Read the attributes section if there is one.
6976   // We read from the end because gas seems to put it near the end of
6977   // the section headers.
6978   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6979   const unsigned char* ps =
6980     sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6981   for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6982     {
6983       elfcpp::Shdr<32, big_endian> shdr(ps);
6984       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6985         {
6986           section_offset_type section_offset = shdr.get_sh_offset();
6987           section_size_type section_size =
6988             convert_to_section_size_type(shdr.get_sh_size());
6989           const unsigned char* view =
6990             this->get_view(section_offset, section_size, true, false);
6991           this->attributes_section_data_ =
6992             new Attributes_section_data(view, section_size);
6993           break;
6994         }
6995     }
6996 }
6997
6998 // Stub_addend_reader methods.
6999
7000 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7001
7002 template<bool big_endian>
7003 elfcpp::Elf_types<32>::Elf_Swxword
7004 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7005     unsigned int r_type,
7006     const unsigned char* view,
7007     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7008 {
7009   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
7010
7011   switch (r_type)
7012     {
7013     case elfcpp::R_ARM_CALL:
7014     case elfcpp::R_ARM_JUMP24:
7015     case elfcpp::R_ARM_PLT32:
7016       {
7017         typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7018         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7019         Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7020         return Bits<26>::sign_extend32(val << 2);
7021       }
7022
7023     case elfcpp::R_ARM_THM_CALL:
7024     case elfcpp::R_ARM_THM_JUMP24:
7025     case elfcpp::R_ARM_THM_XPC22:
7026       {
7027         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7028         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7029         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7030         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7031         return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7032       }
7033
7034     case elfcpp::R_ARM_THM_JUMP19:
7035       {
7036         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7037         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7038         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7039         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7040         return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7041       }
7042
7043     default:
7044       gold_unreachable();
7045     }
7046 }
7047
7048 // Arm_output_data_got methods.
7049
7050 // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
7051 // The first one is initialized to be 1, which is the module index for
7052 // the main executable and the second one 0.  A reloc of the type
7053 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7054 // be applied by gold.  GSYM is a global symbol.
7055 //
7056 template<bool big_endian>
7057 void
7058 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7059     unsigned int got_type,
7060     Symbol* gsym)
7061 {
7062   if (gsym->has_got_offset(got_type))
7063     return;
7064
7065   // We are doing a static link.  Just mark it as belong to module 1,
7066   // the executable.
7067   unsigned int got_offset = this->add_constant(1);
7068   gsym->set_got_offset(got_type, got_offset);
7069   got_offset = this->add_constant(0);
7070   this->static_relocs_.push_back(Static_reloc(got_offset,
7071                                               elfcpp::R_ARM_TLS_DTPOFF32,
7072                                               gsym));
7073 }
7074
7075 // Same as the above but for a local symbol.
7076
7077 template<bool big_endian>
7078 void
7079 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7080   unsigned int got_type,
7081   Sized_relobj_file<32, big_endian>* object,
7082   unsigned int index)
7083 {
7084   if (object->local_has_got_offset(index, got_type))
7085     return;
7086
7087   // We are doing a static link.  Just mark it as belong to module 1,
7088   // the executable.
7089   unsigned int got_offset = this->add_constant(1);
7090   object->set_local_got_offset(index, got_type, got_offset);
7091   got_offset = this->add_constant(0);
7092   this->static_relocs_.push_back(Static_reloc(got_offset,
7093                                               elfcpp::R_ARM_TLS_DTPOFF32,
7094                                               object, index));
7095 }
7096
7097 template<bool big_endian>
7098 void
7099 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7100 {
7101   // Call parent to write out GOT.
7102   Output_data_got<32, big_endian>::do_write(of);
7103
7104   // We are done if there is no fix up.
7105   if (this->static_relocs_.empty())
7106     return;
7107
7108   gold_assert(parameters->doing_static_link());
7109
7110   const off_t offset = this->offset();
7111   const section_size_type oview_size =
7112     convert_to_section_size_type(this->data_size());
7113   unsigned char* const oview = of->get_output_view(offset, oview_size);
7114
7115   Output_segment* tls_segment = this->layout_->tls_segment();
7116   gold_assert(tls_segment != NULL);
7117
7118   // The thread pointer $tp points to the TCB, which is followed by the
7119   // TLS.  So we need to adjust $tp relative addressing by this amount.
7120   Arm_address aligned_tcb_size =
7121     align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7122
7123   for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7124     {
7125       Static_reloc& reloc(this->static_relocs_[i]);
7126
7127       Arm_address value;
7128       if (!reloc.symbol_is_global())
7129         {
7130           Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7131           const Symbol_value<32>* psymval =
7132             reloc.relobj()->local_symbol(reloc.index());
7133
7134           // We are doing static linking.  Issue an error and skip this
7135           // relocation if the symbol is undefined or in a discarded_section.
7136           bool is_ordinary;
7137           unsigned int shndx = psymval->input_shndx(&is_ordinary);
7138           if ((shndx == elfcpp::SHN_UNDEF)
7139               || (is_ordinary
7140                   && shndx != elfcpp::SHN_UNDEF
7141                   && !object->is_section_included(shndx)
7142                   && !this->symbol_table_->is_section_folded(object, shndx)))
7143             {
7144               gold_error(_("undefined or discarded local symbol %u from "
7145                            " object %s in GOT"),
7146                          reloc.index(), reloc.relobj()->name().c_str());
7147               continue;
7148             }
7149
7150           value = psymval->value(object, 0);
7151         }
7152       else
7153         {
7154           const Symbol* gsym = reloc.symbol();
7155           gold_assert(gsym != NULL);
7156           if (gsym->is_forwarder())
7157             gsym = this->symbol_table_->resolve_forwards(gsym);
7158
7159           // We are doing static linking.  Issue an error and skip this
7160           // relocation if the symbol is undefined or in a discarded_section
7161           // unless it is a weakly_undefined symbol.
7162           if ((gsym->is_defined_in_discarded_section()
7163                || gsym->is_undefined())
7164               && !gsym->is_weak_undefined())
7165             {
7166               gold_error(_("undefined or discarded symbol %s in GOT"),
7167                          gsym->name());
7168               continue;
7169             }
7170
7171           if (!gsym->is_weak_undefined())
7172             {
7173               const Sized_symbol<32>* sym =
7174                 static_cast<const Sized_symbol<32>*>(gsym);
7175               value = sym->value();
7176             }
7177           else
7178               value = 0;
7179         }
7180
7181       unsigned got_offset = reloc.got_offset();
7182       gold_assert(got_offset < oview_size);
7183
7184       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7185       Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7186       Valtype x;
7187       switch (reloc.r_type())
7188         {
7189         case elfcpp::R_ARM_TLS_DTPOFF32:
7190           x = value;
7191           break;
7192         case elfcpp::R_ARM_TLS_TPOFF32:
7193           x = value + aligned_tcb_size;
7194           break;
7195         default:
7196           gold_unreachable();
7197         }
7198       elfcpp::Swap<32, big_endian>::writeval(wv, x);
7199     }
7200
7201   of->write_output_view(offset, oview_size, oview);
7202 }
7203
7204 // A class to handle the PLT data.
7205 // This is an abstract base class that handles most of the linker details
7206 // but does not know the actual contents of PLT entries.  The derived
7207 // classes below fill in those details.
7208
7209 template<bool big_endian>
7210 class Output_data_plt_arm : public Output_section_data
7211 {
7212  public:
7213   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7214     Reloc_section;
7215
7216   Output_data_plt_arm(Layout*, uint64_t addralign, Output_data_space*);
7217
7218   // Add an entry to the PLT.
7219   void
7220   add_entry(Symbol* gsym);
7221
7222   // Return the .rel.plt section data.
7223   const Reloc_section*
7224   rel_plt() const
7225   { return this->rel_; }
7226
7227   // Return the number of PLT entries.
7228   unsigned int
7229   entry_count() const
7230   { return this->count_; }
7231
7232   // Return the offset of the first non-reserved PLT entry.
7233   unsigned int
7234   first_plt_entry_offset() const
7235   { return this->do_first_plt_entry_offset(); }
7236
7237   // Return the size of a PLT entry.
7238   unsigned int
7239   get_plt_entry_size() const
7240   { return this->do_get_plt_entry_size(); }
7241
7242  protected:
7243   // Fill in the first PLT entry.
7244   void
7245   fill_first_plt_entry(unsigned char* pov,
7246                        Arm_address got_address,
7247                        Arm_address plt_address)
7248   { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
7249
7250   void
7251   fill_plt_entry(unsigned char* pov,
7252                  Arm_address got_address,
7253                  Arm_address plt_address,
7254                  unsigned int got_offset,
7255                  unsigned int plt_offset)
7256   { do_fill_plt_entry(pov, got_address, plt_address, got_offset, plt_offset); }
7257
7258   virtual unsigned int
7259   do_first_plt_entry_offset() const = 0;
7260
7261   virtual unsigned int
7262   do_get_plt_entry_size() const = 0;
7263
7264   virtual void
7265   do_fill_first_plt_entry(unsigned char* pov,
7266                           Arm_address got_address,
7267                           Arm_address plt_address) = 0;
7268
7269   virtual void
7270   do_fill_plt_entry(unsigned char* pov,
7271                     Arm_address got_address,
7272                     Arm_address plt_address,
7273                     unsigned int got_offset,
7274                     unsigned int plt_offset) = 0;
7275
7276   void
7277   do_adjust_output_section(Output_section* os);
7278
7279   // Write to a map file.
7280   void
7281   do_print_to_mapfile(Mapfile* mapfile) const
7282   { mapfile->print_output_data(this, _("** PLT")); }
7283
7284  private:
7285   // Set the final size.
7286   void
7287   set_final_data_size()
7288   {
7289     this->set_data_size(this->first_plt_entry_offset()
7290                         + this->count_ * this->get_plt_entry_size());
7291   }
7292
7293   // Write out the PLT data.
7294   void
7295   do_write(Output_file*);
7296
7297   // The reloc section.
7298   Reloc_section* rel_;
7299   // The .got.plt section.
7300   Output_data_space* got_plt_;
7301   // The number of PLT entries.
7302   unsigned int count_;
7303 };
7304
7305 // Create the PLT section.  The ordinary .got section is an argument,
7306 // since we need to refer to the start.  We also create our own .got
7307 // section just for PLT entries.
7308
7309 template<bool big_endian>
7310 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7311                                                      uint64_t addralign,
7312                                                      Output_data_space* got_plt)
7313   : Output_section_data(addralign), got_plt_(got_plt), count_(0)
7314 {
7315   this->rel_ = new Reloc_section(false);
7316   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7317                                   elfcpp::SHF_ALLOC, this->rel_,
7318                                   ORDER_DYNAMIC_PLT_RELOCS, false);
7319 }
7320
7321 template<bool big_endian>
7322 void
7323 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7324 {
7325   os->set_entsize(0);
7326 }
7327
7328 // Add an entry to the PLT.
7329
7330 template<bool big_endian>
7331 void
7332 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7333 {
7334   gold_assert(!gsym->has_plt_offset());
7335
7336   // Note that when setting the PLT offset we skip the initial
7337   // reserved PLT entry.
7338   gsym->set_plt_offset((this->count_) * this->get_plt_entry_size()
7339                        + this->first_plt_entry_offset());
7340
7341   ++this->count_;
7342
7343   section_offset_type got_offset = this->got_plt_->current_data_size();
7344
7345   // Every PLT entry needs a GOT entry which points back to the PLT
7346   // entry (this will be changed by the dynamic linker, normally
7347   // lazily when the function is called).
7348   this->got_plt_->set_current_data_size(got_offset + 4);
7349
7350   // Every PLT entry needs a reloc.
7351   gsym->set_needs_dynsym_entry();
7352   this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7353                          got_offset);
7354
7355   // Note that we don't need to save the symbol.  The contents of the
7356   // PLT are independent of which symbols are used.  The symbols only
7357   // appear in the relocations.
7358 }
7359
7360 template<bool big_endian>
7361 class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
7362 {
7363  public:
7364   Output_data_plt_arm_standard(Layout* layout, Output_data_space* got_plt)
7365     : Output_data_plt_arm<big_endian>(layout, 4, got_plt)
7366   { }
7367
7368  protected:
7369   // Return the offset of the first non-reserved PLT entry.
7370   virtual unsigned int
7371   do_first_plt_entry_offset() const
7372   { return sizeof(first_plt_entry); }
7373
7374   // Return the size of a PLT entry.
7375   virtual unsigned int
7376   do_get_plt_entry_size() const
7377   { return sizeof(plt_entry); }
7378
7379   virtual void
7380   do_fill_first_plt_entry(unsigned char* pov,
7381                           Arm_address got_address,
7382                           Arm_address plt_address);
7383
7384   virtual void
7385   do_fill_plt_entry(unsigned char* pov,
7386                     Arm_address got_address,
7387                     Arm_address plt_address,
7388                     unsigned int got_offset,
7389                     unsigned int plt_offset);
7390
7391  private:
7392   // Template for the first PLT entry.
7393   static const uint32_t first_plt_entry[5];
7394
7395   // Template for subsequent PLT entries.
7396   static const uint32_t plt_entry[3];
7397 };
7398
7399 // ARM PLTs.
7400 // FIXME:  This is not very flexible.  Right now this has only been tested
7401 // on armv5te.  If we are to support additional architecture features like
7402 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7403
7404 // The first entry in the PLT.
7405 template<bool big_endian>
7406 const uint32_t Output_data_plt_arm_standard<big_endian>::first_plt_entry[5] =
7407 {
7408   0xe52de004,   // str   lr, [sp, #-4]!
7409   0xe59fe004,   // ldr   lr, [pc, #4]
7410   0xe08fe00e,   // add   lr, pc, lr
7411   0xe5bef008,   // ldr   pc, [lr, #8]!
7412   0x00000000,   // &GOT[0] - .
7413 };
7414
7415 template<bool big_endian>
7416 void
7417 Output_data_plt_arm_standard<big_endian>::do_fill_first_plt_entry(
7418     unsigned char* pov,
7419     Arm_address got_address,
7420     Arm_address plt_address)
7421 {
7422   // Write first PLT entry.  All but the last word are constants.
7423   const size_t num_first_plt_words = (sizeof(first_plt_entry)
7424                                       / sizeof(plt_entry[0]));
7425   for (size_t i = 0; i < num_first_plt_words - 1; i++)
7426     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7427   // Last word in first PLT entry is &GOT[0] - .
7428   elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7429                                          got_address - (plt_address + 16));
7430 }
7431
7432 // Subsequent entries in the PLT.
7433
7434 template<bool big_endian>
7435 const uint32_t Output_data_plt_arm_standard<big_endian>::plt_entry[3] =
7436 {
7437   0xe28fc600,   // add   ip, pc, #0xNN00000
7438   0xe28cca00,   // add   ip, ip, #0xNN000
7439   0xe5bcf000,   // ldr   pc, [ip, #0xNNN]!
7440 };
7441
7442 template<bool big_endian>
7443 void
7444 Output_data_plt_arm_standard<big_endian>::do_fill_plt_entry(
7445     unsigned char* pov,
7446     Arm_address got_address,
7447     Arm_address plt_address,
7448     unsigned int got_offset,
7449     unsigned int plt_offset)
7450 {
7451   int32_t offset = ((got_address + got_offset)
7452                     - (plt_address + plt_offset + 8));
7453
7454   gold_assert(offset >= 0 && offset < 0x0fffffff);
7455   uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7456   elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7457   uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7458   elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7459   uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7460   elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7461 }
7462
7463 // Write out the PLT.  This uses the hand-coded instructions above,
7464 // and adjusts them as needed.  This is all specified by the arm ELF
7465 // Processor Supplement.
7466
7467 template<bool big_endian>
7468 void
7469 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7470 {
7471   const off_t offset = this->offset();
7472   const section_size_type oview_size =
7473     convert_to_section_size_type(this->data_size());
7474   unsigned char* const oview = of->get_output_view(offset, oview_size);
7475
7476   const off_t got_file_offset = this->got_plt_->offset();
7477   const section_size_type got_size =
7478     convert_to_section_size_type(this->got_plt_->data_size());
7479   unsigned char* const got_view = of->get_output_view(got_file_offset,
7480                                                       got_size);
7481   unsigned char* pov = oview;
7482
7483   Arm_address plt_address = this->address();
7484   Arm_address got_address = this->got_plt_->address();
7485
7486   // Write first PLT entry.
7487   this->fill_first_plt_entry(pov, got_address, plt_address);
7488   pov += this->first_plt_entry_offset();
7489
7490   unsigned char* got_pov = got_view;
7491
7492   memset(got_pov, 0, 12);
7493   got_pov += 12;
7494
7495   unsigned int plt_offset = this->first_plt_entry_offset();
7496   unsigned int got_offset = 12;
7497   const unsigned int count = this->count_;
7498   for (unsigned int i = 0;
7499        i < count;
7500        ++i,
7501          pov += this->get_plt_entry_size(),
7502          got_pov += 4,
7503          plt_offset += this->get_plt_entry_size(),
7504          got_offset += 4)
7505     {
7506       // Set and adjust the PLT entry itself.
7507       this->fill_plt_entry(pov, got_address, plt_address,
7508                            got_offset, plt_offset);
7509
7510       // Set the entry in the GOT.
7511       elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7512     }
7513
7514   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7515   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7516
7517   of->write_output_view(offset, oview_size, oview);
7518   of->write_output_view(got_file_offset, got_size, got_view);
7519 }
7520
7521 // Create a PLT entry for a global symbol.
7522
7523 template<bool big_endian>
7524 void
7525 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7526                                        Symbol* gsym)
7527 {
7528   if (gsym->has_plt_offset())
7529     return;
7530
7531   if (this->plt_ == NULL)
7532     {
7533       // Create the GOT sections first.
7534       this->got_section(symtab, layout);
7535
7536       this->plt_ = this->make_data_plt(layout, this->got_plt_);
7537
7538       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7539                                       (elfcpp::SHF_ALLOC
7540                                        | elfcpp::SHF_EXECINSTR),
7541                                       this->plt_, ORDER_PLT, false);
7542     }
7543   this->plt_->add_entry(gsym);
7544 }
7545
7546 // Return the number of entries in the PLT.
7547
7548 template<bool big_endian>
7549 unsigned int
7550 Target_arm<big_endian>::plt_entry_count() const
7551 {
7552   if (this->plt_ == NULL)
7553     return 0;
7554   return this->plt_->entry_count();
7555 }
7556
7557 // Return the offset of the first non-reserved PLT entry.
7558
7559 template<bool big_endian>
7560 unsigned int
7561 Target_arm<big_endian>::first_plt_entry_offset() const
7562 {
7563   return this->plt_->first_plt_entry_offset();
7564 }
7565
7566 // Return the size of each PLT entry.
7567
7568 template<bool big_endian>
7569 unsigned int
7570 Target_arm<big_endian>::plt_entry_size() const
7571 {
7572   return this->plt_->get_plt_entry_size();
7573 }
7574
7575 // Get the section to use for TLS_DESC relocations.
7576
7577 template<bool big_endian>
7578 typename Target_arm<big_endian>::Reloc_section*
7579 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7580 {
7581   return this->plt_section()->rel_tls_desc(layout);
7582 }
7583
7584 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7585
7586 template<bool big_endian>
7587 void
7588 Target_arm<big_endian>::define_tls_base_symbol(
7589     Symbol_table* symtab,
7590     Layout* layout)
7591 {
7592   if (this->tls_base_symbol_defined_)
7593     return;
7594
7595   Output_segment* tls_segment = layout->tls_segment();
7596   if (tls_segment != NULL)
7597     {
7598       bool is_exec = parameters->options().output_is_executable();
7599       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7600                                        Symbol_table::PREDEFINED,
7601                                        tls_segment, 0, 0,
7602                                        elfcpp::STT_TLS,
7603                                        elfcpp::STB_LOCAL,
7604                                        elfcpp::STV_HIDDEN, 0,
7605                                        (is_exec
7606                                         ? Symbol::SEGMENT_END
7607                                         : Symbol::SEGMENT_START),
7608                                        true);
7609     }
7610   this->tls_base_symbol_defined_ = true;
7611 }
7612
7613 // Create a GOT entry for the TLS module index.
7614
7615 template<bool big_endian>
7616 unsigned int
7617 Target_arm<big_endian>::got_mod_index_entry(
7618     Symbol_table* symtab,
7619     Layout* layout,
7620     Sized_relobj_file<32, big_endian>* object)
7621 {
7622   if (this->got_mod_index_offset_ == -1U)
7623     {
7624       gold_assert(symtab != NULL && layout != NULL && object != NULL);
7625       Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7626       unsigned int got_offset;
7627       if (!parameters->doing_static_link())
7628         {
7629           got_offset = got->add_constant(0);
7630           Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7631           rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7632                              got_offset);
7633         }
7634       else
7635         {
7636           // We are doing a static link.  Just mark it as belong to module 1,
7637           // the executable.
7638           got_offset = got->add_constant(1);
7639         }
7640
7641       got->add_constant(0);
7642       this->got_mod_index_offset_ = got_offset;
7643     }
7644   return this->got_mod_index_offset_;
7645 }
7646
7647 // Optimize the TLS relocation type based on what we know about the
7648 // symbol.  IS_FINAL is true if the final address of this symbol is
7649 // known at link time.
7650
7651 template<bool big_endian>
7652 tls::Tls_optimization
7653 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7654 {
7655   // FIXME: Currently we do not do any TLS optimization.
7656   return tls::TLSOPT_NONE;
7657 }
7658
7659 // Get the Reference_flags for a particular relocation.
7660
7661 template<bool big_endian>
7662 int
7663 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
7664 {
7665   switch (r_type)
7666     {
7667     case elfcpp::R_ARM_NONE:
7668     case elfcpp::R_ARM_V4BX:
7669     case elfcpp::R_ARM_GNU_VTENTRY:
7670     case elfcpp::R_ARM_GNU_VTINHERIT:
7671       // No symbol reference.
7672       return 0;
7673
7674     case elfcpp::R_ARM_ABS32:
7675     case elfcpp::R_ARM_ABS16:
7676     case elfcpp::R_ARM_ABS12:
7677     case elfcpp::R_ARM_THM_ABS5:
7678     case elfcpp::R_ARM_ABS8:
7679     case elfcpp::R_ARM_BASE_ABS:
7680     case elfcpp::R_ARM_MOVW_ABS_NC:
7681     case elfcpp::R_ARM_MOVT_ABS:
7682     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7683     case elfcpp::R_ARM_THM_MOVT_ABS:
7684     case elfcpp::R_ARM_ABS32_NOI:
7685       return Symbol::ABSOLUTE_REF;
7686
7687     case elfcpp::R_ARM_REL32:
7688     case elfcpp::R_ARM_LDR_PC_G0:
7689     case elfcpp::R_ARM_SBREL32:
7690     case elfcpp::R_ARM_THM_PC8:
7691     case elfcpp::R_ARM_BASE_PREL:
7692     case elfcpp::R_ARM_MOVW_PREL_NC:
7693     case elfcpp::R_ARM_MOVT_PREL:
7694     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7695     case elfcpp::R_ARM_THM_MOVT_PREL:
7696     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7697     case elfcpp::R_ARM_THM_PC12:
7698     case elfcpp::R_ARM_REL32_NOI:
7699     case elfcpp::R_ARM_ALU_PC_G0_NC:
7700     case elfcpp::R_ARM_ALU_PC_G0:
7701     case elfcpp::R_ARM_ALU_PC_G1_NC:
7702     case elfcpp::R_ARM_ALU_PC_G1:
7703     case elfcpp::R_ARM_ALU_PC_G2:
7704     case elfcpp::R_ARM_LDR_PC_G1:
7705     case elfcpp::R_ARM_LDR_PC_G2:
7706     case elfcpp::R_ARM_LDRS_PC_G0:
7707     case elfcpp::R_ARM_LDRS_PC_G1:
7708     case elfcpp::R_ARM_LDRS_PC_G2:
7709     case elfcpp::R_ARM_LDC_PC_G0:
7710     case elfcpp::R_ARM_LDC_PC_G1:
7711     case elfcpp::R_ARM_LDC_PC_G2:
7712     case elfcpp::R_ARM_ALU_SB_G0_NC:
7713     case elfcpp::R_ARM_ALU_SB_G0:
7714     case elfcpp::R_ARM_ALU_SB_G1_NC:
7715     case elfcpp::R_ARM_ALU_SB_G1:
7716     case elfcpp::R_ARM_ALU_SB_G2:
7717     case elfcpp::R_ARM_LDR_SB_G0:
7718     case elfcpp::R_ARM_LDR_SB_G1:
7719     case elfcpp::R_ARM_LDR_SB_G2:
7720     case elfcpp::R_ARM_LDRS_SB_G0:
7721     case elfcpp::R_ARM_LDRS_SB_G1:
7722     case elfcpp::R_ARM_LDRS_SB_G2:
7723     case elfcpp::R_ARM_LDC_SB_G0:
7724     case elfcpp::R_ARM_LDC_SB_G1:
7725     case elfcpp::R_ARM_LDC_SB_G2:
7726     case elfcpp::R_ARM_MOVW_BREL_NC:
7727     case elfcpp::R_ARM_MOVT_BREL:
7728     case elfcpp::R_ARM_MOVW_BREL:
7729     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7730     case elfcpp::R_ARM_THM_MOVT_BREL:
7731     case elfcpp::R_ARM_THM_MOVW_BREL:
7732     case elfcpp::R_ARM_GOTOFF32:
7733     case elfcpp::R_ARM_GOTOFF12:
7734     case elfcpp::R_ARM_SBREL31:
7735       return Symbol::RELATIVE_REF;
7736
7737     case elfcpp::R_ARM_PLT32:
7738     case elfcpp::R_ARM_CALL:
7739     case elfcpp::R_ARM_JUMP24:
7740     case elfcpp::R_ARM_THM_CALL:
7741     case elfcpp::R_ARM_THM_JUMP24:
7742     case elfcpp::R_ARM_THM_JUMP19:
7743     case elfcpp::R_ARM_THM_JUMP6:
7744     case elfcpp::R_ARM_THM_JUMP11:
7745     case elfcpp::R_ARM_THM_JUMP8:
7746     // R_ARM_PREL31 is not used to relocate call/jump instructions but
7747     // in unwind tables. It may point to functions via PLTs.
7748     // So we treat it like call/jump relocations above.
7749     case elfcpp::R_ARM_PREL31:
7750       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
7751
7752     case elfcpp::R_ARM_GOT_BREL:
7753     case elfcpp::R_ARM_GOT_ABS:
7754     case elfcpp::R_ARM_GOT_PREL:
7755       // Absolute in GOT.
7756       return Symbol::ABSOLUTE_REF;
7757
7758     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
7759     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
7760     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
7761     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
7762     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
7763       return Symbol::TLS_REF;
7764
7765     case elfcpp::R_ARM_TARGET1:
7766     case elfcpp::R_ARM_TARGET2:
7767     case elfcpp::R_ARM_COPY:
7768     case elfcpp::R_ARM_GLOB_DAT:
7769     case elfcpp::R_ARM_JUMP_SLOT:
7770     case elfcpp::R_ARM_RELATIVE:
7771     case elfcpp::R_ARM_PC24:
7772     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7773     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7774     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7775     default:
7776       // Not expected.  We will give an error later.
7777       return 0;
7778     }
7779 }
7780
7781 // Report an unsupported relocation against a local symbol.
7782
7783 template<bool big_endian>
7784 void
7785 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7786     Sized_relobj_file<32, big_endian>* object,
7787     unsigned int r_type)
7788 {
7789   gold_error(_("%s: unsupported reloc %u against local symbol"),
7790              object->name().c_str(), r_type);
7791 }
7792
7793 // We are about to emit a dynamic relocation of type R_TYPE.  If the
7794 // dynamic linker does not support it, issue an error.  The GNU linker
7795 // only issues a non-PIC error for an allocated read-only section.
7796 // Here we know the section is allocated, but we don't know that it is
7797 // read-only.  But we check for all the relocation types which the
7798 // glibc dynamic linker supports, so it seems appropriate to issue an
7799 // error even if the section is not read-only.
7800
7801 template<bool big_endian>
7802 void
7803 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7804                                             unsigned int r_type)
7805 {
7806   switch (r_type)
7807     {
7808     // These are the relocation types supported by glibc for ARM.
7809     case elfcpp::R_ARM_RELATIVE:
7810     case elfcpp::R_ARM_COPY:
7811     case elfcpp::R_ARM_GLOB_DAT:
7812     case elfcpp::R_ARM_JUMP_SLOT:
7813     case elfcpp::R_ARM_ABS32:
7814     case elfcpp::R_ARM_ABS32_NOI:
7815     case elfcpp::R_ARM_PC24:
7816     // FIXME: The following 3 types are not supported by Android's dynamic
7817     // linker.
7818     case elfcpp::R_ARM_TLS_DTPMOD32:
7819     case elfcpp::R_ARM_TLS_DTPOFF32:
7820     case elfcpp::R_ARM_TLS_TPOFF32:
7821       return;
7822
7823     default:
7824       {
7825         // This prevents us from issuing more than one error per reloc
7826         // section.  But we can still wind up issuing more than one
7827         // error per object file.
7828         if (this->issued_non_pic_error_)
7829           return;
7830         const Arm_reloc_property* reloc_property =
7831           arm_reloc_property_table->get_reloc_property(r_type);
7832         gold_assert(reloc_property != NULL);
7833         object->error(_("requires unsupported dynamic reloc %s; "
7834                       "recompile with -fPIC"),
7835                       reloc_property->name().c_str());
7836         this->issued_non_pic_error_ = true;
7837         return;
7838       }
7839
7840     case elfcpp::R_ARM_NONE:
7841       gold_unreachable();
7842     }
7843 }
7844
7845 // Scan a relocation for a local symbol.
7846 // FIXME: This only handles a subset of relocation types used by Android
7847 // on ARM v5te devices.
7848
7849 template<bool big_endian>
7850 inline void
7851 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7852                                     Layout* layout,
7853                                     Target_arm* target,
7854                                     Sized_relobj_file<32, big_endian>* object,
7855                                     unsigned int data_shndx,
7856                                     Output_section* output_section,
7857                                     const elfcpp::Rel<32, big_endian>& reloc,
7858                                     unsigned int r_type,
7859                                     const elfcpp::Sym<32, big_endian>& lsym,
7860                                     bool is_discarded)
7861 {
7862   if (is_discarded)
7863     return;
7864
7865   r_type = get_real_reloc_type(r_type);
7866   switch (r_type)
7867     {
7868     case elfcpp::R_ARM_NONE:
7869     case elfcpp::R_ARM_V4BX:
7870     case elfcpp::R_ARM_GNU_VTENTRY:
7871     case elfcpp::R_ARM_GNU_VTINHERIT:
7872       break;
7873
7874     case elfcpp::R_ARM_ABS32:
7875     case elfcpp::R_ARM_ABS32_NOI:
7876       // If building a shared library (or a position-independent
7877       // executable), we need to create a dynamic relocation for
7878       // this location. The relocation applied at link time will
7879       // apply the link-time value, so we flag the location with
7880       // an R_ARM_RELATIVE relocation so the dynamic loader can
7881       // relocate it easily.
7882       if (parameters->options().output_is_position_independent())
7883         {
7884           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7885           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7886           // If we are to add more other reloc types than R_ARM_ABS32,
7887           // we need to add check_non_pic(object, r_type) here.
7888           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7889                                       output_section, data_shndx,
7890                                       reloc.get_r_offset());
7891         }
7892       break;
7893
7894     case elfcpp::R_ARM_ABS16:
7895     case elfcpp::R_ARM_ABS12:
7896     case elfcpp::R_ARM_THM_ABS5:
7897     case elfcpp::R_ARM_ABS8:
7898     case elfcpp::R_ARM_BASE_ABS:
7899     case elfcpp::R_ARM_MOVW_ABS_NC:
7900     case elfcpp::R_ARM_MOVT_ABS:
7901     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7902     case elfcpp::R_ARM_THM_MOVT_ABS:
7903       // If building a shared library (or a position-independent
7904       // executable), we need to create a dynamic relocation for
7905       // this location. Because the addend needs to remain in the
7906       // data section, we need to be careful not to apply this
7907       // relocation statically.
7908       if (parameters->options().output_is_position_independent())
7909         {
7910           check_non_pic(object, r_type);
7911           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7912           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7913           if (lsym.get_st_type() != elfcpp::STT_SECTION)
7914             rel_dyn->add_local(object, r_sym, r_type, output_section,
7915                                data_shndx, reloc.get_r_offset());
7916           else
7917             {
7918               gold_assert(lsym.get_st_value() == 0);
7919               unsigned int shndx = lsym.get_st_shndx();
7920               bool is_ordinary;
7921               shndx = object->adjust_sym_shndx(r_sym, shndx,
7922                                                &is_ordinary);
7923               if (!is_ordinary)
7924                 object->error(_("section symbol %u has bad shndx %u"),
7925                               r_sym, shndx);
7926               else
7927                 rel_dyn->add_local_section(object, shndx,
7928                                            r_type, output_section,
7929                                            data_shndx, reloc.get_r_offset());
7930             }
7931         }
7932       break;
7933
7934     case elfcpp::R_ARM_REL32:
7935     case elfcpp::R_ARM_LDR_PC_G0:
7936     case elfcpp::R_ARM_SBREL32:
7937     case elfcpp::R_ARM_THM_CALL:
7938     case elfcpp::R_ARM_THM_PC8:
7939     case elfcpp::R_ARM_BASE_PREL:
7940     case elfcpp::R_ARM_PLT32:
7941     case elfcpp::R_ARM_CALL:
7942     case elfcpp::R_ARM_JUMP24:
7943     case elfcpp::R_ARM_THM_JUMP24:
7944     case elfcpp::R_ARM_SBREL31:
7945     case elfcpp::R_ARM_PREL31:
7946     case elfcpp::R_ARM_MOVW_PREL_NC:
7947     case elfcpp::R_ARM_MOVT_PREL:
7948     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7949     case elfcpp::R_ARM_THM_MOVT_PREL:
7950     case elfcpp::R_ARM_THM_JUMP19:
7951     case elfcpp::R_ARM_THM_JUMP6:
7952     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7953     case elfcpp::R_ARM_THM_PC12:
7954     case elfcpp::R_ARM_REL32_NOI:
7955     case elfcpp::R_ARM_ALU_PC_G0_NC:
7956     case elfcpp::R_ARM_ALU_PC_G0:
7957     case elfcpp::R_ARM_ALU_PC_G1_NC:
7958     case elfcpp::R_ARM_ALU_PC_G1:
7959     case elfcpp::R_ARM_ALU_PC_G2:
7960     case elfcpp::R_ARM_LDR_PC_G1:
7961     case elfcpp::R_ARM_LDR_PC_G2:
7962     case elfcpp::R_ARM_LDRS_PC_G0:
7963     case elfcpp::R_ARM_LDRS_PC_G1:
7964     case elfcpp::R_ARM_LDRS_PC_G2:
7965     case elfcpp::R_ARM_LDC_PC_G0:
7966     case elfcpp::R_ARM_LDC_PC_G1:
7967     case elfcpp::R_ARM_LDC_PC_G2:
7968     case elfcpp::R_ARM_ALU_SB_G0_NC:
7969     case elfcpp::R_ARM_ALU_SB_G0:
7970     case elfcpp::R_ARM_ALU_SB_G1_NC:
7971     case elfcpp::R_ARM_ALU_SB_G1:
7972     case elfcpp::R_ARM_ALU_SB_G2:
7973     case elfcpp::R_ARM_LDR_SB_G0:
7974     case elfcpp::R_ARM_LDR_SB_G1:
7975     case elfcpp::R_ARM_LDR_SB_G2:
7976     case elfcpp::R_ARM_LDRS_SB_G0:
7977     case elfcpp::R_ARM_LDRS_SB_G1:
7978     case elfcpp::R_ARM_LDRS_SB_G2:
7979     case elfcpp::R_ARM_LDC_SB_G0:
7980     case elfcpp::R_ARM_LDC_SB_G1:
7981     case elfcpp::R_ARM_LDC_SB_G2:
7982     case elfcpp::R_ARM_MOVW_BREL_NC:
7983     case elfcpp::R_ARM_MOVT_BREL:
7984     case elfcpp::R_ARM_MOVW_BREL:
7985     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7986     case elfcpp::R_ARM_THM_MOVT_BREL:
7987     case elfcpp::R_ARM_THM_MOVW_BREL:
7988     case elfcpp::R_ARM_THM_JUMP11:
7989     case elfcpp::R_ARM_THM_JUMP8:
7990       // We don't need to do anything for a relative addressing relocation
7991       // against a local symbol if it does not reference the GOT.
7992       break;
7993
7994     case elfcpp::R_ARM_GOTOFF32:
7995     case elfcpp::R_ARM_GOTOFF12:
7996       // We need a GOT section:
7997       target->got_section(symtab, layout);
7998       break;
7999
8000     case elfcpp::R_ARM_GOT_BREL:
8001     case elfcpp::R_ARM_GOT_PREL:
8002       {
8003         // The symbol requires a GOT entry.
8004         Arm_output_data_got<big_endian>* got =
8005           target->got_section(symtab, layout);
8006         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8007         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
8008           {
8009             // If we are generating a shared object, we need to add a
8010             // dynamic RELATIVE relocation for this symbol's GOT entry.
8011             if (parameters->options().output_is_position_independent())
8012               {
8013                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8014                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8015                 rel_dyn->add_local_relative(
8016                     object, r_sym, elfcpp::R_ARM_RELATIVE, got,
8017                     object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
8018               }
8019           }
8020       }
8021       break;
8022
8023     case elfcpp::R_ARM_TARGET1:
8024     case elfcpp::R_ARM_TARGET2:
8025       // This should have been mapped to another type already.
8026       // Fall through.
8027     case elfcpp::R_ARM_COPY:
8028     case elfcpp::R_ARM_GLOB_DAT:
8029     case elfcpp::R_ARM_JUMP_SLOT:
8030     case elfcpp::R_ARM_RELATIVE:
8031       // These are relocations which should only be seen by the
8032       // dynamic linker, and should never be seen here.
8033       gold_error(_("%s: unexpected reloc %u in object file"),
8034                  object->name().c_str(), r_type);
8035       break;
8036
8037
8038       // These are initial TLS relocs, which are expected when
8039       // linking.
8040     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8041     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8042     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8043     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8044     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8045       {
8046         bool output_is_shared = parameters->options().shared();
8047         const tls::Tls_optimization optimized_type
8048             = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
8049                                                          r_type);
8050         switch (r_type)
8051           {
8052           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8053             if (optimized_type == tls::TLSOPT_NONE)
8054               {
8055                 // Create a pair of GOT entries for the module index and
8056                 // dtv-relative offset.
8057                 Arm_output_data_got<big_endian>* got
8058                     = target->got_section(symtab, layout);
8059                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8060                 unsigned int shndx = lsym.get_st_shndx();
8061                 bool is_ordinary;
8062                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
8063                 if (!is_ordinary)
8064                   {
8065                     object->error(_("local symbol %u has bad shndx %u"),
8066                                   r_sym, shndx);
8067                     break;
8068                   }
8069
8070                 if (!parameters->doing_static_link())
8071                   got->add_local_pair_with_rel(object, r_sym, shndx,
8072                                                GOT_TYPE_TLS_PAIR,
8073                                                target->rel_dyn_section(layout),
8074                                                elfcpp::R_ARM_TLS_DTPMOD32);
8075                 else
8076                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
8077                                                       object, r_sym);
8078               }
8079             else
8080               // FIXME: TLS optimization not supported yet.
8081               gold_unreachable();
8082             break;
8083
8084           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
8085             if (optimized_type == tls::TLSOPT_NONE)
8086               {
8087                 // Create a GOT entry for the module index.
8088                 target->got_mod_index_entry(symtab, layout, object);
8089               }
8090             else
8091               // FIXME: TLS optimization not supported yet.
8092               gold_unreachable();
8093             break;
8094
8095           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
8096             break;
8097
8098           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
8099             layout->set_has_static_tls();
8100             if (optimized_type == tls::TLSOPT_NONE)
8101               {
8102                 // Create a GOT entry for the tp-relative offset.
8103                 Arm_output_data_got<big_endian>* got
8104                   = target->got_section(symtab, layout);
8105                 unsigned int r_sym =
8106                    elfcpp::elf_r_sym<32>(reloc.get_r_info());
8107                 if (!parameters->doing_static_link())
8108                     got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
8109                                             target->rel_dyn_section(layout),
8110                                             elfcpp::R_ARM_TLS_TPOFF32);
8111                 else if (!object->local_has_got_offset(r_sym,
8112                                                        GOT_TYPE_TLS_OFFSET))
8113                   {
8114                     got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
8115                     unsigned int got_offset =
8116                       object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
8117                     got->add_static_reloc(got_offset,
8118                                           elfcpp::R_ARM_TLS_TPOFF32, object,
8119                                           r_sym);
8120                   }
8121               }
8122             else
8123               // FIXME: TLS optimization not supported yet.
8124               gold_unreachable();
8125             break;
8126
8127           case elfcpp::R_ARM_TLS_LE32:          // Local-exec
8128             layout->set_has_static_tls();
8129             if (output_is_shared)
8130               {
8131                 // We need to create a dynamic relocation.
8132                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8133                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8134                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8135                 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8136                                    output_section, data_shndx,
8137                                    reloc.get_r_offset());
8138               }
8139             break;
8140
8141           default:
8142             gold_unreachable();
8143           }
8144       }
8145       break;
8146
8147     case elfcpp::R_ARM_PC24:
8148     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8149     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8150     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8151     default:
8152       unsupported_reloc_local(object, r_type);
8153       break;
8154     }
8155 }
8156
8157 // Report an unsupported relocation against a global symbol.
8158
8159 template<bool big_endian>
8160 void
8161 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8162     Sized_relobj_file<32, big_endian>* object,
8163     unsigned int r_type,
8164     Symbol* gsym)
8165 {
8166   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8167              object->name().c_str(), r_type, gsym->demangled_name().c_str());
8168 }
8169
8170 template<bool big_endian>
8171 inline bool
8172 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8173     unsigned int r_type)
8174 {
8175   switch (r_type)
8176     {
8177     case elfcpp::R_ARM_PC24:
8178     case elfcpp::R_ARM_THM_CALL:
8179     case elfcpp::R_ARM_PLT32:
8180     case elfcpp::R_ARM_CALL:
8181     case elfcpp::R_ARM_JUMP24:
8182     case elfcpp::R_ARM_THM_JUMP24:
8183     case elfcpp::R_ARM_SBREL31:
8184     case elfcpp::R_ARM_PREL31:
8185     case elfcpp::R_ARM_THM_JUMP19:
8186     case elfcpp::R_ARM_THM_JUMP6:
8187     case elfcpp::R_ARM_THM_JUMP11:
8188     case elfcpp::R_ARM_THM_JUMP8:
8189       // All the relocations above are branches except SBREL31 and PREL31.
8190       return false;
8191
8192     default:
8193       // Be conservative and assume this is a function pointer.
8194       return true;
8195     }
8196 }
8197
8198 template<bool big_endian>
8199 inline bool
8200 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8201   Symbol_table*,
8202   Layout*,
8203   Target_arm<big_endian>* target,
8204   Sized_relobj_file<32, big_endian>*,
8205   unsigned int,
8206   Output_section*,
8207   const elfcpp::Rel<32, big_endian>&,
8208   unsigned int r_type,
8209   const elfcpp::Sym<32, big_endian>&)
8210 {
8211   r_type = target->get_real_reloc_type(r_type);
8212   return possible_function_pointer_reloc(r_type);
8213 }
8214
8215 template<bool big_endian>
8216 inline bool
8217 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8218   Symbol_table*,
8219   Layout*,
8220   Target_arm<big_endian>* target,
8221   Sized_relobj_file<32, big_endian>*,
8222   unsigned int,
8223   Output_section*,
8224   const elfcpp::Rel<32, big_endian>&,
8225   unsigned int r_type,
8226   Symbol* gsym)
8227 {
8228   // GOT is not a function.
8229   if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8230     return false;
8231
8232   r_type = target->get_real_reloc_type(r_type);
8233   return possible_function_pointer_reloc(r_type);
8234 }
8235
8236 // Scan a relocation for a global symbol.
8237
8238 template<bool big_endian>
8239 inline void
8240 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8241                                      Layout* layout,
8242                                      Target_arm* target,
8243                                      Sized_relobj_file<32, big_endian>* object,
8244                                      unsigned int data_shndx,
8245                                      Output_section* output_section,
8246                                      const elfcpp::Rel<32, big_endian>& reloc,
8247                                      unsigned int r_type,
8248                                      Symbol* gsym)
8249 {
8250   // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8251   // section.  We check here to avoid creating a dynamic reloc against
8252   // _GLOBAL_OFFSET_TABLE_.
8253   if (!target->has_got_section()
8254       && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8255     target->got_section(symtab, layout);
8256
8257   r_type = get_real_reloc_type(r_type);
8258   switch (r_type)
8259     {
8260     case elfcpp::R_ARM_NONE:
8261     case elfcpp::R_ARM_V4BX:
8262     case elfcpp::R_ARM_GNU_VTENTRY:
8263     case elfcpp::R_ARM_GNU_VTINHERIT:
8264       break;
8265
8266     case elfcpp::R_ARM_ABS32:
8267     case elfcpp::R_ARM_ABS16:
8268     case elfcpp::R_ARM_ABS12:
8269     case elfcpp::R_ARM_THM_ABS5:
8270     case elfcpp::R_ARM_ABS8:
8271     case elfcpp::R_ARM_BASE_ABS:
8272     case elfcpp::R_ARM_MOVW_ABS_NC:
8273     case elfcpp::R_ARM_MOVT_ABS:
8274     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8275     case elfcpp::R_ARM_THM_MOVT_ABS:
8276     case elfcpp::R_ARM_ABS32_NOI:
8277       // Absolute addressing relocations.
8278       {
8279         // Make a PLT entry if necessary.
8280         if (this->symbol_needs_plt_entry(gsym))
8281           {
8282             target->make_plt_entry(symtab, layout, gsym);
8283             // Since this is not a PC-relative relocation, we may be
8284             // taking the address of a function. In that case we need to
8285             // set the entry in the dynamic symbol table to the address of
8286             // the PLT entry.
8287             if (gsym->is_from_dynobj() && !parameters->options().shared())
8288               gsym->set_needs_dynsym_value();
8289           }
8290         // Make a dynamic relocation if necessary.
8291         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8292           {
8293             if (gsym->may_need_copy_reloc())
8294               {
8295                 target->copy_reloc(symtab, layout, object,
8296                                    data_shndx, output_section, gsym, reloc);
8297               }
8298             else if ((r_type == elfcpp::R_ARM_ABS32
8299                       || r_type == elfcpp::R_ARM_ABS32_NOI)
8300                      && gsym->can_use_relative_reloc(false))
8301               {
8302                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8303                 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8304                                              output_section, object,
8305                                              data_shndx, reloc.get_r_offset());
8306               }
8307             else
8308               {
8309                 check_non_pic(object, r_type);
8310                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8311                 rel_dyn->add_global(gsym, r_type, output_section, object,
8312                                     data_shndx, reloc.get_r_offset());
8313               }
8314           }
8315       }
8316       break;
8317
8318     case elfcpp::R_ARM_GOTOFF32:
8319     case elfcpp::R_ARM_GOTOFF12:
8320       // We need a GOT section.
8321       target->got_section(symtab, layout);
8322       break;
8323
8324     case elfcpp::R_ARM_REL32:
8325     case elfcpp::R_ARM_LDR_PC_G0:
8326     case elfcpp::R_ARM_SBREL32:
8327     case elfcpp::R_ARM_THM_PC8:
8328     case elfcpp::R_ARM_BASE_PREL:
8329     case elfcpp::R_ARM_MOVW_PREL_NC:
8330     case elfcpp::R_ARM_MOVT_PREL:
8331     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8332     case elfcpp::R_ARM_THM_MOVT_PREL:
8333     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8334     case elfcpp::R_ARM_THM_PC12:
8335     case elfcpp::R_ARM_REL32_NOI:
8336     case elfcpp::R_ARM_ALU_PC_G0_NC:
8337     case elfcpp::R_ARM_ALU_PC_G0:
8338     case elfcpp::R_ARM_ALU_PC_G1_NC:
8339     case elfcpp::R_ARM_ALU_PC_G1:
8340     case elfcpp::R_ARM_ALU_PC_G2:
8341     case elfcpp::R_ARM_LDR_PC_G1:
8342     case elfcpp::R_ARM_LDR_PC_G2:
8343     case elfcpp::R_ARM_LDRS_PC_G0:
8344     case elfcpp::R_ARM_LDRS_PC_G1:
8345     case elfcpp::R_ARM_LDRS_PC_G2:
8346     case elfcpp::R_ARM_LDC_PC_G0:
8347     case elfcpp::R_ARM_LDC_PC_G1:
8348     case elfcpp::R_ARM_LDC_PC_G2:
8349     case elfcpp::R_ARM_ALU_SB_G0_NC:
8350     case elfcpp::R_ARM_ALU_SB_G0:
8351     case elfcpp::R_ARM_ALU_SB_G1_NC:
8352     case elfcpp::R_ARM_ALU_SB_G1:
8353     case elfcpp::R_ARM_ALU_SB_G2:
8354     case elfcpp::R_ARM_LDR_SB_G0:
8355     case elfcpp::R_ARM_LDR_SB_G1:
8356     case elfcpp::R_ARM_LDR_SB_G2:
8357     case elfcpp::R_ARM_LDRS_SB_G0:
8358     case elfcpp::R_ARM_LDRS_SB_G1:
8359     case elfcpp::R_ARM_LDRS_SB_G2:
8360     case elfcpp::R_ARM_LDC_SB_G0:
8361     case elfcpp::R_ARM_LDC_SB_G1:
8362     case elfcpp::R_ARM_LDC_SB_G2:
8363     case elfcpp::R_ARM_MOVW_BREL_NC:
8364     case elfcpp::R_ARM_MOVT_BREL:
8365     case elfcpp::R_ARM_MOVW_BREL:
8366     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8367     case elfcpp::R_ARM_THM_MOVT_BREL:
8368     case elfcpp::R_ARM_THM_MOVW_BREL:
8369       // Relative addressing relocations.
8370       {
8371         // Make a dynamic relocation if necessary.
8372         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8373           {
8374             if (target->may_need_copy_reloc(gsym))
8375               {
8376                 target->copy_reloc(symtab, layout, object,
8377                                    data_shndx, output_section, gsym, reloc);
8378               }
8379             else
8380               {
8381                 check_non_pic(object, r_type);
8382                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8383                 rel_dyn->add_global(gsym, r_type, output_section, object,
8384                                     data_shndx, reloc.get_r_offset());
8385               }
8386           }
8387       }
8388       break;
8389
8390     case elfcpp::R_ARM_THM_CALL:
8391     case elfcpp::R_ARM_PLT32:
8392     case elfcpp::R_ARM_CALL:
8393     case elfcpp::R_ARM_JUMP24:
8394     case elfcpp::R_ARM_THM_JUMP24:
8395     case elfcpp::R_ARM_SBREL31:
8396     case elfcpp::R_ARM_PREL31:
8397     case elfcpp::R_ARM_THM_JUMP19:
8398     case elfcpp::R_ARM_THM_JUMP6:
8399     case elfcpp::R_ARM_THM_JUMP11:
8400     case elfcpp::R_ARM_THM_JUMP8:
8401       // All the relocation above are branches except for the PREL31 ones.
8402       // A PREL31 relocation can point to a personality function in a shared
8403       // library.  In that case we want to use a PLT because we want to
8404       // call the personality routine and the dynamic linkers we care about
8405       // do not support dynamic PREL31 relocations. An REL31 relocation may
8406       // point to a function whose unwinding behaviour is being described but
8407       // we will not mistakenly generate a PLT for that because we should use
8408       // a local section symbol.
8409
8410       // If the symbol is fully resolved, this is just a relative
8411       // local reloc.  Otherwise we need a PLT entry.
8412       if (gsym->final_value_is_known())
8413         break;
8414       // If building a shared library, we can also skip the PLT entry
8415       // if the symbol is defined in the output file and is protected
8416       // or hidden.
8417       if (gsym->is_defined()
8418           && !gsym->is_from_dynobj()
8419           && !gsym->is_preemptible())
8420         break;
8421       target->make_plt_entry(symtab, layout, gsym);
8422       break;
8423
8424     case elfcpp::R_ARM_GOT_BREL:
8425     case elfcpp::R_ARM_GOT_ABS:
8426     case elfcpp::R_ARM_GOT_PREL:
8427       {
8428         // The symbol requires a GOT entry.
8429         Arm_output_data_got<big_endian>* got =
8430           target->got_section(symtab, layout);
8431         if (gsym->final_value_is_known())
8432           got->add_global(gsym, GOT_TYPE_STANDARD);
8433         else
8434           {
8435             // If this symbol is not fully resolved, we need to add a
8436             // GOT entry with a dynamic relocation.
8437             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8438             if (gsym->is_from_dynobj()
8439                 || gsym->is_undefined()
8440                 || gsym->is_preemptible()
8441                 || (gsym->visibility() == elfcpp::STV_PROTECTED
8442                     && parameters->options().shared()))
8443               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8444                                        rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8445             else
8446               {
8447                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
8448                   rel_dyn->add_global_relative(
8449                       gsym, elfcpp::R_ARM_RELATIVE, got,
8450                       gsym->got_offset(GOT_TYPE_STANDARD));
8451               }
8452           }
8453       }
8454       break;
8455
8456     case elfcpp::R_ARM_TARGET1:
8457     case elfcpp::R_ARM_TARGET2:
8458       // These should have been mapped to other types already.
8459       // Fall through.
8460     case elfcpp::R_ARM_COPY:
8461     case elfcpp::R_ARM_GLOB_DAT:
8462     case elfcpp::R_ARM_JUMP_SLOT:
8463     case elfcpp::R_ARM_RELATIVE:
8464       // These are relocations which should only be seen by the
8465       // dynamic linker, and should never be seen here.
8466       gold_error(_("%s: unexpected reloc %u in object file"),
8467                  object->name().c_str(), r_type);
8468       break;
8469
8470       // These are initial tls relocs, which are expected when
8471       // linking.
8472     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8473     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8474     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8475     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8476     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8477       {
8478         const bool is_final = gsym->final_value_is_known();
8479         const tls::Tls_optimization optimized_type
8480             = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8481         switch (r_type)
8482           {
8483           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8484             if (optimized_type == tls::TLSOPT_NONE)
8485               {
8486                 // Create a pair of GOT entries for the module index and
8487                 // dtv-relative offset.
8488                 Arm_output_data_got<big_endian>* got
8489                     = target->got_section(symtab, layout);
8490                 if (!parameters->doing_static_link())
8491                   got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8492                                                 target->rel_dyn_section(layout),
8493                                                 elfcpp::R_ARM_TLS_DTPMOD32,
8494                                                 elfcpp::R_ARM_TLS_DTPOFF32);
8495                 else
8496                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8497               }
8498             else
8499               // FIXME: TLS optimization not supported yet.
8500               gold_unreachable();
8501             break;
8502
8503           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
8504             if (optimized_type == tls::TLSOPT_NONE)
8505               {
8506                 // Create a GOT entry for the module index.
8507                 target->got_mod_index_entry(symtab, layout, object);
8508               }
8509             else
8510               // FIXME: TLS optimization not supported yet.
8511               gold_unreachable();
8512             break;
8513
8514           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
8515             break;
8516
8517           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
8518             layout->set_has_static_tls();
8519             if (optimized_type == tls::TLSOPT_NONE)
8520               {
8521                 // Create a GOT entry for the tp-relative offset.
8522                 Arm_output_data_got<big_endian>* got
8523                   = target->got_section(symtab, layout);
8524                 if (!parameters->doing_static_link())
8525                   got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
8526                                            target->rel_dyn_section(layout),
8527                                            elfcpp::R_ARM_TLS_TPOFF32);
8528                 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
8529                   {
8530                     got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
8531                     unsigned int got_offset =
8532                        gsym->got_offset(GOT_TYPE_TLS_OFFSET);
8533                     got->add_static_reloc(got_offset,
8534                                           elfcpp::R_ARM_TLS_TPOFF32, gsym);
8535                   }
8536               }
8537             else
8538               // FIXME: TLS optimization not supported yet.
8539               gold_unreachable();
8540             break;
8541
8542           case elfcpp::R_ARM_TLS_LE32:  // Local-exec
8543             layout->set_has_static_tls();
8544             if (parameters->options().shared())
8545               {
8546                 // We need to create a dynamic relocation.
8547                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8548                 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
8549                                     output_section, object,
8550                                     data_shndx, reloc.get_r_offset());
8551               }
8552             break;
8553
8554           default:
8555             gold_unreachable();
8556           }
8557       }
8558       break;
8559
8560     case elfcpp::R_ARM_PC24:
8561     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8562     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8563     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8564     default:
8565       unsupported_reloc_global(object, r_type, gsym);
8566       break;
8567     }
8568 }
8569
8570 // Process relocations for gc.
8571
8572 template<bool big_endian>
8573 void
8574 Target_arm<big_endian>::gc_process_relocs(
8575     Symbol_table* symtab,
8576     Layout* layout,
8577     Sized_relobj_file<32, big_endian>* object,
8578     unsigned int data_shndx,
8579     unsigned int,
8580     const unsigned char* prelocs,
8581     size_t reloc_count,
8582     Output_section* output_section,
8583     bool needs_special_offset_handling,
8584     size_t local_symbol_count,
8585     const unsigned char* plocal_symbols)
8586 {
8587   typedef Target_arm<big_endian> Arm;
8588   typedef typename Target_arm<big_endian>::Scan Scan;
8589
8590   gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
8591                           typename Target_arm::Relocatable_size_for_reloc>(
8592     symtab,
8593     layout,
8594     this,
8595     object,
8596     data_shndx,
8597     prelocs,
8598     reloc_count,
8599     output_section,
8600     needs_special_offset_handling,
8601     local_symbol_count,
8602     plocal_symbols);
8603 }
8604
8605 // Scan relocations for a section.
8606
8607 template<bool big_endian>
8608 void
8609 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
8610                                     Layout* layout,
8611                                     Sized_relobj_file<32, big_endian>* object,
8612                                     unsigned int data_shndx,
8613                                     unsigned int sh_type,
8614                                     const unsigned char* prelocs,
8615                                     size_t reloc_count,
8616                                     Output_section* output_section,
8617                                     bool needs_special_offset_handling,
8618                                     size_t local_symbol_count,
8619                                     const unsigned char* plocal_symbols)
8620 {
8621   typedef typename Target_arm<big_endian>::Scan Scan;
8622   if (sh_type == elfcpp::SHT_RELA)
8623     {
8624       gold_error(_("%s: unsupported RELA reloc section"),
8625                  object->name().c_str());
8626       return;
8627     }
8628
8629   gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
8630     symtab,
8631     layout,
8632     this,
8633     object,
8634     data_shndx,
8635     prelocs,
8636     reloc_count,
8637     output_section,
8638     needs_special_offset_handling,
8639     local_symbol_count,
8640     plocal_symbols);
8641 }
8642
8643 // Finalize the sections.
8644
8645 template<bool big_endian>
8646 void
8647 Target_arm<big_endian>::do_finalize_sections(
8648     Layout* layout,
8649     const Input_objects* input_objects,
8650     Symbol_table*)
8651 {
8652   bool merged_any_attributes = false;
8653   // Merge processor-specific flags.
8654   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
8655        p != input_objects->relobj_end();
8656        ++p)
8657     {
8658       Arm_relobj<big_endian>* arm_relobj =
8659         Arm_relobj<big_endian>::as_arm_relobj(*p);
8660       if (arm_relobj->merge_flags_and_attributes())
8661         {
8662           this->merge_processor_specific_flags(
8663               arm_relobj->name(),
8664               arm_relobj->processor_specific_flags());
8665           this->merge_object_attributes(arm_relobj->name().c_str(),
8666                                         arm_relobj->attributes_section_data());
8667           merged_any_attributes = true;
8668         }
8669     }
8670
8671   for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
8672        p != input_objects->dynobj_end();
8673        ++p)
8674     {
8675       Arm_dynobj<big_endian>* arm_dynobj =
8676         Arm_dynobj<big_endian>::as_arm_dynobj(*p);
8677       this->merge_processor_specific_flags(
8678           arm_dynobj->name(),
8679           arm_dynobj->processor_specific_flags());
8680       this->merge_object_attributes(arm_dynobj->name().c_str(),
8681                                     arm_dynobj->attributes_section_data());
8682       merged_any_attributes = true;
8683     }
8684
8685   // Create an empty uninitialized attribute section if we still don't have it
8686   // at this moment.  This happens if there is no attributes sections in all
8687   // inputs.
8688   if (this->attributes_section_data_ == NULL)
8689     this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
8690
8691   const Object_attribute* cpu_arch_attr =
8692     this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
8693   // Check if we need to use Cortex-A8 workaround.
8694   if (parameters->options().user_set_fix_cortex_a8())
8695     this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
8696   else
8697     {
8698       // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
8699       // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
8700       // profile.
8701       const Object_attribute* cpu_arch_profile_attr =
8702         this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
8703       this->fix_cortex_a8_ =
8704         (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
8705          && (cpu_arch_profile_attr->int_value() == 'A'
8706              || cpu_arch_profile_attr->int_value() == 0));
8707     }
8708
8709   // Check if we can use V4BX interworking.
8710   // The V4BX interworking stub contains BX instruction,
8711   // which is not specified for some profiles.
8712   if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
8713       && !this->may_use_v4t_interworking())
8714     gold_error(_("unable to provide V4BX reloc interworking fix up; "
8715                  "the target profile does not support BX instruction"));
8716
8717   // Fill in some more dynamic tags.
8718   const Reloc_section* rel_plt = (this->plt_ == NULL
8719                                   ? NULL
8720                                   : this->plt_->rel_plt());
8721   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
8722                                   this->rel_dyn_, true, false);
8723
8724   // Emit any relocs we saved in an attempt to avoid generating COPY
8725   // relocs.
8726   if (this->copy_relocs_.any_saved_relocs())
8727     this->copy_relocs_.emit(this->rel_dyn_section(layout));
8728
8729   // Handle the .ARM.exidx section.
8730   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8731
8732   if (!parameters->options().relocatable())
8733     {
8734       if (exidx_section != NULL
8735           && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
8736         {
8737           // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8738           // the .ARM.exidx section.
8739           if (!layout->script_options()->saw_phdrs_clause())
8740             {
8741               gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
8742                                                       0)
8743                           == NULL);
8744               Output_segment*  exidx_segment =
8745                 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8746               exidx_segment->add_output_section_to_nonload(exidx_section,
8747                                                            elfcpp::PF_R);
8748             }
8749         }
8750     }
8751
8752   // Create an .ARM.attributes section if we have merged any attributes
8753   // from inputs.
8754   if (merged_any_attributes)
8755     {
8756       Output_attributes_section_data* attributes_section =
8757       new Output_attributes_section_data(*this->attributes_section_data_);
8758       layout->add_output_section_data(".ARM.attributes",
8759                                       elfcpp::SHT_ARM_ATTRIBUTES, 0,
8760                                       attributes_section, ORDER_INVALID,
8761                                       false);
8762     }
8763
8764   // Fix up links in section EXIDX headers.
8765   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
8766        p != layout->section_list().end();
8767        ++p)
8768     if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
8769       {
8770         Arm_output_section<big_endian>* os =
8771           Arm_output_section<big_endian>::as_arm_output_section(*p);
8772         os->set_exidx_section_link();
8773       }
8774 }
8775
8776 // Return whether a direct absolute static relocation needs to be applied.
8777 // In cases where Scan::local() or Scan::global() has created
8778 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8779 // of the relocation is carried in the data, and we must not
8780 // apply the static relocation.
8781
8782 template<bool big_endian>
8783 inline bool
8784 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8785     const Sized_symbol<32>* gsym,
8786     unsigned int r_type,
8787     bool is_32bit,
8788     Output_section* output_section)
8789 {
8790   // If the output section is not allocated, then we didn't call
8791   // scan_relocs, we didn't create a dynamic reloc, and we must apply
8792   // the reloc here.
8793   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8794       return true;
8795
8796   int ref_flags = Scan::get_reference_flags(r_type);
8797
8798   // For local symbols, we will have created a non-RELATIVE dynamic
8799   // relocation only if (a) the output is position independent,
8800   // (b) the relocation is absolute (not pc- or segment-relative), and
8801   // (c) the relocation is not 32 bits wide.
8802   if (gsym == NULL)
8803     return !(parameters->options().output_is_position_independent()
8804              && (ref_flags & Symbol::ABSOLUTE_REF)
8805              && !is_32bit);
8806
8807   // For global symbols, we use the same helper routines used in the
8808   // scan pass.  If we did not create a dynamic relocation, or if we
8809   // created a RELATIVE dynamic relocation, we should apply the static
8810   // relocation.
8811   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8812   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8813                  && gsym->can_use_relative_reloc(ref_flags
8814                                                  & Symbol::FUNCTION_CALL);
8815   return !has_dyn || is_rel;
8816 }
8817
8818 // Perform a relocation.
8819
8820 template<bool big_endian>
8821 inline bool
8822 Target_arm<big_endian>::Relocate::relocate(
8823     const Relocate_info<32, big_endian>* relinfo,
8824     Target_arm* target,
8825     Output_section* output_section,
8826     size_t relnum,
8827     const elfcpp::Rel<32, big_endian>& rel,
8828     unsigned int r_type,
8829     const Sized_symbol<32>* gsym,
8830     const Symbol_value<32>* psymval,
8831     unsigned char* view,
8832     Arm_address address,
8833     section_size_type view_size)
8834 {
8835   typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8836
8837   r_type = get_real_reloc_type(r_type);
8838   const Arm_reloc_property* reloc_property =
8839     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8840   if (reloc_property == NULL)
8841     {
8842       std::string reloc_name =
8843         arm_reloc_property_table->reloc_name_in_error_message(r_type);
8844       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8845                              _("cannot relocate %s in object file"),
8846                              reloc_name.c_str());
8847       return true;
8848     }
8849
8850   const Arm_relobj<big_endian>* object =
8851     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8852
8853   // If the final branch target of a relocation is THUMB instruction, this
8854   // is 1.  Otherwise it is 0.
8855   Arm_address thumb_bit = 0;
8856   Symbol_value<32> symval;
8857   bool is_weakly_undefined_without_plt = false;
8858   bool have_got_offset = false;
8859   unsigned int got_offset = 0;
8860
8861   // If the relocation uses the GOT entry of a symbol instead of the symbol
8862   // itself, we don't care about whether the symbol is defined or what kind
8863   // of symbol it is.
8864   if (reloc_property->uses_got_entry())
8865     {
8866       // Get the GOT offset.
8867       // The GOT pointer points to the end of the GOT section.
8868       // We need to subtract the size of the GOT section to get
8869       // the actual offset to use in the relocation.
8870       // TODO: We should move GOT offset computing code in TLS relocations
8871       // to here.
8872       switch (r_type)
8873         {
8874         case elfcpp::R_ARM_GOT_BREL:
8875         case elfcpp::R_ARM_GOT_PREL:
8876           if (gsym != NULL)
8877             {
8878               gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8879               got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8880                             - target->got_size());
8881             }
8882           else
8883             {
8884               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8885               gold_assert(object->local_has_got_offset(r_sym,
8886                                                        GOT_TYPE_STANDARD));
8887               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8888                             - target->got_size());
8889             }
8890           have_got_offset = true;
8891           break;
8892
8893         default:
8894           break;
8895         }
8896     }
8897   else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8898     {
8899       if (gsym != NULL)
8900         {
8901           // This is a global symbol.  Determine if we use PLT and if the
8902           // final target is THUMB.
8903           if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
8904             {
8905               // This uses a PLT, change the symbol value.
8906               symval.set_output_value(target->plt_section()->address()
8907                                       + gsym->plt_offset());
8908               psymval = &symval;
8909             }
8910           else if (gsym->is_weak_undefined())
8911             {
8912               // This is a weakly undefined symbol and we do not use PLT
8913               // for this relocation.  A branch targeting this symbol will
8914               // be converted into an NOP.
8915               is_weakly_undefined_without_plt = true;
8916             }
8917           else if (gsym->is_undefined() && reloc_property->uses_symbol())
8918             {
8919               // This relocation uses the symbol value but the symbol is
8920               // undefined.  Exit early and have the caller reporting an
8921               // error.
8922               return true;
8923             }
8924           else
8925             {
8926               // Set thumb bit if symbol:
8927               // -Has type STT_ARM_TFUNC or
8928               // -Has type STT_FUNC, is defined and with LSB in value set.
8929               thumb_bit =
8930                 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8931                  || (gsym->type() == elfcpp::STT_FUNC
8932                      && !gsym->is_undefined()
8933                      && ((psymval->value(object, 0) & 1) != 0)))
8934                 ? 1
8935                 : 0);
8936             }
8937         }
8938       else
8939         {
8940           // This is a local symbol.  Determine if the final target is THUMB.
8941           // We saved this information when all the local symbols were read.
8942           elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8943           unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8944           thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8945         }
8946     }
8947   else
8948     {
8949       // This is a fake relocation synthesized for a stub.  It does not have
8950       // a real symbol.  We just look at the LSB of the symbol value to
8951       // determine if the target is THUMB or not.
8952       thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8953     }
8954
8955   // Strip LSB if this points to a THUMB target.
8956   if (thumb_bit != 0
8957       && reloc_property->uses_thumb_bit()
8958       && ((psymval->value(object, 0) & 1) != 0))
8959     {
8960       Arm_address stripped_value =
8961         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8962       symval.set_output_value(stripped_value);
8963       psymval = &symval;
8964     }
8965
8966   // To look up relocation stubs, we need to pass the symbol table index of
8967   // a local symbol.
8968   unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8969
8970   // Get the addressing origin of the output segment defining the
8971   // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8972   Arm_address sym_origin = 0;
8973   if (reloc_property->uses_symbol_base())
8974     {
8975       if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8976         // R_ARM_BASE_ABS with the NULL symbol will give the
8977         // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8978         // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8979         sym_origin = target->got_plt_section()->address();
8980       else if (gsym == NULL)
8981         sym_origin = 0;
8982       else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8983         sym_origin = gsym->output_segment()->vaddr();
8984       else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
8985         sym_origin = gsym->output_data()->address();
8986
8987       // TODO: Assumes the segment base to be zero for the global symbols
8988       // till the proper support for the segment-base-relative addressing
8989       // will be implemented.  This is consistent with GNU ld.
8990     }
8991
8992   // For relative addressing relocation, find out the relative address base.
8993   Arm_address relative_address_base = 0;
8994   switch(reloc_property->relative_address_base())
8995     {
8996     case Arm_reloc_property::RAB_NONE:
8997     // Relocations with relative address bases RAB_TLS and RAB_tp are
8998     // handled by relocate_tls.  So we do not need to do anything here.
8999     case Arm_reloc_property::RAB_TLS:
9000     case Arm_reloc_property::RAB_tp:
9001       break;
9002     case Arm_reloc_property::RAB_B_S:
9003       relative_address_base = sym_origin;
9004       break;
9005     case Arm_reloc_property::RAB_GOT_ORG:
9006       relative_address_base = target->got_plt_section()->address();
9007       break;
9008     case Arm_reloc_property::RAB_P:
9009       relative_address_base = address;
9010       break;
9011     case Arm_reloc_property::RAB_Pa:
9012       relative_address_base = address & 0xfffffffcU;
9013       break;
9014     default:
9015       gold_unreachable();
9016     }
9017
9018   typename Arm_relocate_functions::Status reloc_status =
9019         Arm_relocate_functions::STATUS_OKAY;
9020   bool check_overflow = reloc_property->checks_overflow();
9021   switch (r_type)
9022     {
9023     case elfcpp::R_ARM_NONE:
9024       break;
9025
9026     case elfcpp::R_ARM_ABS8:
9027       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9028         reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
9029       break;
9030
9031     case elfcpp::R_ARM_ABS12:
9032       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9033         reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
9034       break;
9035
9036     case elfcpp::R_ARM_ABS16:
9037       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9038         reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
9039       break;
9040
9041     case elfcpp::R_ARM_ABS32:
9042       if (should_apply_static_reloc(gsym, r_type, true, output_section))
9043         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9044                                                      thumb_bit);
9045       break;
9046
9047     case elfcpp::R_ARM_ABS32_NOI:
9048       if (should_apply_static_reloc(gsym, r_type, true, output_section))
9049         // No thumb bit for this relocation: (S + A)
9050         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9051                                                      0);
9052       break;
9053
9054     case elfcpp::R_ARM_MOVW_ABS_NC:
9055       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9056         reloc_status = Arm_relocate_functions::movw(view, object, psymval,
9057                                                     0, thumb_bit,
9058                                                     check_overflow);
9059       break;
9060
9061     case elfcpp::R_ARM_MOVT_ABS:
9062       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9063         reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
9064       break;
9065
9066     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9067       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9068         reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
9069                                                         0, thumb_bit, false);
9070       break;
9071
9072     case elfcpp::R_ARM_THM_MOVT_ABS:
9073       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9074         reloc_status = Arm_relocate_functions::thm_movt(view, object,
9075                                                         psymval, 0);
9076       break;
9077
9078     case elfcpp::R_ARM_MOVW_PREL_NC:
9079     case elfcpp::R_ARM_MOVW_BREL_NC:
9080     case elfcpp::R_ARM_MOVW_BREL:
9081       reloc_status =
9082         Arm_relocate_functions::movw(view, object, psymval,
9083                                      relative_address_base, thumb_bit,
9084                                      check_overflow);
9085       break;
9086
9087     case elfcpp::R_ARM_MOVT_PREL:
9088     case elfcpp::R_ARM_MOVT_BREL:
9089       reloc_status =
9090         Arm_relocate_functions::movt(view, object, psymval,
9091                                      relative_address_base);
9092       break;
9093
9094     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9095     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9096     case elfcpp::R_ARM_THM_MOVW_BREL:
9097       reloc_status =
9098         Arm_relocate_functions::thm_movw(view, object, psymval,
9099                                          relative_address_base,
9100                                          thumb_bit, check_overflow);
9101       break;
9102
9103     case elfcpp::R_ARM_THM_MOVT_PREL:
9104     case elfcpp::R_ARM_THM_MOVT_BREL:
9105       reloc_status =
9106         Arm_relocate_functions::thm_movt(view, object, psymval,
9107                                          relative_address_base);
9108       break;
9109
9110     case elfcpp::R_ARM_REL32:
9111       reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9112                                                    address, thumb_bit);
9113       break;
9114
9115     case elfcpp::R_ARM_THM_ABS5:
9116       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9117         reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
9118       break;
9119
9120     // Thumb long branches.
9121     case elfcpp::R_ARM_THM_CALL:
9122     case elfcpp::R_ARM_THM_XPC22:
9123     case elfcpp::R_ARM_THM_JUMP24:
9124       reloc_status =
9125         Arm_relocate_functions::thumb_branch_common(
9126             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9127             thumb_bit, is_weakly_undefined_without_plt);
9128       break;
9129
9130     case elfcpp::R_ARM_GOTOFF32:
9131       {
9132         Arm_address got_origin;
9133         got_origin = target->got_plt_section()->address();
9134         reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9135                                                      got_origin, thumb_bit);
9136       }
9137       break;
9138
9139     case elfcpp::R_ARM_BASE_PREL:
9140       gold_assert(gsym != NULL);
9141       reloc_status =
9142           Arm_relocate_functions::base_prel(view, sym_origin, address);
9143       break;
9144
9145     case elfcpp::R_ARM_BASE_ABS:
9146       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9147         reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
9148       break;
9149
9150     case elfcpp::R_ARM_GOT_BREL:
9151       gold_assert(have_got_offset);
9152       reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
9153       break;
9154
9155     case elfcpp::R_ARM_GOT_PREL:
9156       gold_assert(have_got_offset);
9157       // Get the address origin for GOT PLT, which is allocated right
9158       // after the GOT section, to calculate an absolute address of
9159       // the symbol GOT entry (got_origin + got_offset).
9160       Arm_address got_origin;
9161       got_origin = target->got_plt_section()->address();
9162       reloc_status = Arm_relocate_functions::got_prel(view,
9163                                                       got_origin + got_offset,
9164                                                       address);
9165       break;
9166
9167     case elfcpp::R_ARM_PLT32:
9168     case elfcpp::R_ARM_CALL:
9169     case elfcpp::R_ARM_JUMP24:
9170     case elfcpp::R_ARM_XPC25:
9171       gold_assert(gsym == NULL
9172                   || gsym->has_plt_offset()
9173                   || gsym->final_value_is_known()
9174                   || (gsym->is_defined()
9175                       && !gsym->is_from_dynobj()
9176                       && !gsym->is_preemptible()));
9177       reloc_status =
9178         Arm_relocate_functions::arm_branch_common(
9179             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9180             thumb_bit, is_weakly_undefined_without_plt);
9181       break;
9182
9183     case elfcpp::R_ARM_THM_JUMP19:
9184       reloc_status =
9185         Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9186                                            thumb_bit);
9187       break;
9188
9189     case elfcpp::R_ARM_THM_JUMP6:
9190       reloc_status =
9191         Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9192       break;
9193
9194     case elfcpp::R_ARM_THM_JUMP8:
9195       reloc_status =
9196         Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9197       break;
9198
9199     case elfcpp::R_ARM_THM_JUMP11:
9200       reloc_status =
9201         Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9202       break;
9203
9204     case elfcpp::R_ARM_PREL31:
9205       reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9206                                                     address, thumb_bit);
9207       break;
9208
9209     case elfcpp::R_ARM_V4BX:
9210       if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9211         {
9212           const bool is_v4bx_interworking =
9213               (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9214           reloc_status =
9215             Arm_relocate_functions::v4bx(relinfo, view, object, address,
9216                                          is_v4bx_interworking);
9217         }
9218       break;
9219
9220     case elfcpp::R_ARM_THM_PC8:
9221       reloc_status =
9222         Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9223       break;
9224
9225     case elfcpp::R_ARM_THM_PC12:
9226       reloc_status =
9227         Arm_relocate_functions::thm_pc12(view, object, psymval, address);
9228       break;
9229
9230     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9231       reloc_status =
9232         Arm_relocate_functions::thm_alu11(view, object, psymval, address,
9233                                           thumb_bit);
9234       break;
9235
9236     case elfcpp::R_ARM_ALU_PC_G0_NC:
9237     case elfcpp::R_ARM_ALU_PC_G0:
9238     case elfcpp::R_ARM_ALU_PC_G1_NC:
9239     case elfcpp::R_ARM_ALU_PC_G1:
9240     case elfcpp::R_ARM_ALU_PC_G2:
9241     case elfcpp::R_ARM_ALU_SB_G0_NC:
9242     case elfcpp::R_ARM_ALU_SB_G0:
9243     case elfcpp::R_ARM_ALU_SB_G1_NC:
9244     case elfcpp::R_ARM_ALU_SB_G1:
9245     case elfcpp::R_ARM_ALU_SB_G2:
9246       reloc_status =
9247         Arm_relocate_functions::arm_grp_alu(view, object, psymval,
9248                                             reloc_property->group_index(),
9249                                             relative_address_base,
9250                                             thumb_bit, check_overflow);
9251       break;
9252
9253     case elfcpp::R_ARM_LDR_PC_G0:
9254     case elfcpp::R_ARM_LDR_PC_G1:
9255     case elfcpp::R_ARM_LDR_PC_G2:
9256     case elfcpp::R_ARM_LDR_SB_G0:
9257     case elfcpp::R_ARM_LDR_SB_G1:
9258     case elfcpp::R_ARM_LDR_SB_G2:
9259       reloc_status =
9260           Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9261                                               reloc_property->group_index(),
9262                                               relative_address_base);
9263       break;
9264
9265     case elfcpp::R_ARM_LDRS_PC_G0:
9266     case elfcpp::R_ARM_LDRS_PC_G1:
9267     case elfcpp::R_ARM_LDRS_PC_G2:
9268     case elfcpp::R_ARM_LDRS_SB_G0:
9269     case elfcpp::R_ARM_LDRS_SB_G1:
9270     case elfcpp::R_ARM_LDRS_SB_G2:
9271       reloc_status =
9272           Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9273                                                reloc_property->group_index(),
9274                                                relative_address_base);
9275       break;
9276
9277     case elfcpp::R_ARM_LDC_PC_G0:
9278     case elfcpp::R_ARM_LDC_PC_G1:
9279     case elfcpp::R_ARM_LDC_PC_G2:
9280     case elfcpp::R_ARM_LDC_SB_G0:
9281     case elfcpp::R_ARM_LDC_SB_G1:
9282     case elfcpp::R_ARM_LDC_SB_G2:
9283       reloc_status =
9284           Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9285                                               reloc_property->group_index(),
9286                                               relative_address_base);
9287       break;
9288
9289       // These are initial tls relocs, which are expected when
9290       // linking.
9291     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9292     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9293     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9294     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9295     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9296       reloc_status =
9297         this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9298                            view, address, view_size);
9299       break;
9300
9301     // The known and unknown unsupported and/or deprecated relocations.
9302     case elfcpp::R_ARM_PC24:
9303     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9304     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9305     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9306     default:
9307       // Just silently leave the method. We should get an appropriate error
9308       // message in the scan methods.
9309       break;
9310     }
9311
9312   // Report any errors.
9313   switch (reloc_status)
9314     {
9315     case Arm_relocate_functions::STATUS_OKAY:
9316       break;
9317     case Arm_relocate_functions::STATUS_OVERFLOW:
9318       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9319                              _("relocation overflow in %s"),
9320                              reloc_property->name().c_str());
9321       break;
9322     case Arm_relocate_functions::STATUS_BAD_RELOC:
9323       gold_error_at_location(
9324         relinfo,
9325         relnum,
9326         rel.get_r_offset(),
9327         _("unexpected opcode while processing relocation %s"),
9328         reloc_property->name().c_str());
9329       break;
9330     default:
9331       gold_unreachable();
9332     }
9333
9334   return true;
9335 }
9336
9337 // Perform a TLS relocation.
9338
9339 template<bool big_endian>
9340 inline typename Arm_relocate_functions<big_endian>::Status
9341 Target_arm<big_endian>::Relocate::relocate_tls(
9342     const Relocate_info<32, big_endian>* relinfo,
9343     Target_arm<big_endian>* target,
9344     size_t relnum,
9345     const elfcpp::Rel<32, big_endian>& rel,
9346     unsigned int r_type,
9347     const Sized_symbol<32>* gsym,
9348     const Symbol_value<32>* psymval,
9349     unsigned char* view,
9350     elfcpp::Elf_types<32>::Elf_Addr address,
9351     section_size_type /*view_size*/ )
9352 {
9353   typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9354   typedef Relocate_functions<32, big_endian> RelocFuncs;
9355   Output_segment* tls_segment = relinfo->layout->tls_segment();
9356
9357   const Sized_relobj_file<32, big_endian>* object = relinfo->object;
9358
9359   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9360
9361   const bool is_final = (gsym == NULL
9362                          ? !parameters->options().shared()
9363                          : gsym->final_value_is_known());
9364   const tls::Tls_optimization optimized_type
9365       = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9366   switch (r_type)
9367     {
9368     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9369         {
9370           unsigned int got_type = GOT_TYPE_TLS_PAIR;
9371           unsigned int got_offset;
9372           if (gsym != NULL)
9373             {
9374               gold_assert(gsym->has_got_offset(got_type));
9375               got_offset = gsym->got_offset(got_type) - target->got_size();
9376             }
9377           else
9378             {
9379               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9380               gold_assert(object->local_has_got_offset(r_sym, got_type));
9381               got_offset = (object->local_got_offset(r_sym, got_type)
9382                             - target->got_size());
9383             }
9384           if (optimized_type == tls::TLSOPT_NONE)
9385             {
9386               Arm_address got_entry =
9387                 target->got_plt_section()->address() + got_offset;
9388
9389               // Relocate the field with the PC relative offset of the pair of
9390               // GOT entries.
9391               RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9392               return ArmRelocFuncs::STATUS_OKAY;
9393             }
9394         }
9395       break;
9396
9397     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9398       if (optimized_type == tls::TLSOPT_NONE)
9399         {
9400           // Relocate the field with the offset of the GOT entry for
9401           // the module index.
9402           unsigned int got_offset;
9403           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9404                         - target->got_size());
9405           Arm_address got_entry =
9406             target->got_plt_section()->address() + got_offset;
9407
9408           // Relocate the field with the PC relative offset of the pair of
9409           // GOT entries.
9410           RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9411           return ArmRelocFuncs::STATUS_OKAY;
9412         }
9413       break;
9414
9415     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9416       RelocFuncs::rel32_unaligned(view, value);
9417       return ArmRelocFuncs::STATUS_OKAY;
9418
9419     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9420       if (optimized_type == tls::TLSOPT_NONE)
9421         {
9422           // Relocate the field with the offset of the GOT entry for
9423           // the tp-relative offset of the symbol.
9424           unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9425           unsigned int got_offset;
9426           if (gsym != NULL)
9427             {
9428               gold_assert(gsym->has_got_offset(got_type));
9429               got_offset = gsym->got_offset(got_type);
9430             }
9431           else
9432             {
9433               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9434               gold_assert(object->local_has_got_offset(r_sym, got_type));
9435               got_offset = object->local_got_offset(r_sym, got_type);
9436             }
9437
9438           // All GOT offsets are relative to the end of the GOT.
9439           got_offset -= target->got_size();
9440
9441           Arm_address got_entry =
9442             target->got_plt_section()->address() + got_offset;
9443
9444           // Relocate the field with the PC relative offset of the GOT entry.
9445           RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9446           return ArmRelocFuncs::STATUS_OKAY;
9447         }
9448       break;
9449
9450     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9451       // If we're creating a shared library, a dynamic relocation will
9452       // have been created for this location, so do not apply it now.
9453       if (!parameters->options().shared())
9454         {
9455           gold_assert(tls_segment != NULL);
9456
9457           // $tp points to the TCB, which is followed by the TLS, so we
9458           // need to add TCB size to the offset.
9459           Arm_address aligned_tcb_size =
9460             align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9461           RelocFuncs::rel32_unaligned(view, value + aligned_tcb_size);
9462
9463         }
9464       return ArmRelocFuncs::STATUS_OKAY;
9465
9466     default:
9467       gold_unreachable();
9468     }
9469
9470   gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9471                          _("unsupported reloc %u"),
9472                          r_type);
9473   return ArmRelocFuncs::STATUS_BAD_RELOC;
9474 }
9475
9476 // Relocate section data.
9477
9478 template<bool big_endian>
9479 void
9480 Target_arm<big_endian>::relocate_section(
9481     const Relocate_info<32, big_endian>* relinfo,
9482     unsigned int sh_type,
9483     const unsigned char* prelocs,
9484     size_t reloc_count,
9485     Output_section* output_section,
9486     bool needs_special_offset_handling,
9487     unsigned char* view,
9488     Arm_address address,
9489     section_size_type view_size,
9490     const Reloc_symbol_changes* reloc_symbol_changes)
9491 {
9492   typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
9493   gold_assert(sh_type == elfcpp::SHT_REL);
9494
9495   // See if we are relocating a relaxed input section.  If so, the view
9496   // covers the whole output section and we need to adjust accordingly.
9497   if (needs_special_offset_handling)
9498     {
9499       const Output_relaxed_input_section* poris =
9500         output_section->find_relaxed_input_section(relinfo->object,
9501                                                    relinfo->data_shndx);
9502       if (poris != NULL)
9503         {
9504           Arm_address section_address = poris->address();
9505           section_size_type section_size = poris->data_size();
9506
9507           gold_assert((section_address >= address)
9508                       && ((section_address + section_size)
9509                           <= (address + view_size)));
9510
9511           off_t offset = section_address - address;
9512           view += offset;
9513           address += offset;
9514           view_size = section_size;
9515         }
9516     }
9517
9518   gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
9519                          Arm_relocate, gold::Default_comdat_behavior>(
9520     relinfo,
9521     this,
9522     prelocs,
9523     reloc_count,
9524     output_section,
9525     needs_special_offset_handling,
9526     view,
9527     address,
9528     view_size,
9529     reloc_symbol_changes);
9530 }
9531
9532 // Return the size of a relocation while scanning during a relocatable
9533 // link.
9534
9535 template<bool big_endian>
9536 unsigned int
9537 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
9538     unsigned int r_type,
9539     Relobj* object)
9540 {
9541   r_type = get_real_reloc_type(r_type);
9542   const Arm_reloc_property* arp =
9543       arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9544   if (arp != NULL)
9545     return arp->size();
9546   else
9547     {
9548       std::string reloc_name =
9549         arm_reloc_property_table->reloc_name_in_error_message(r_type);
9550       gold_error(_("%s: unexpected %s in object file"),
9551                  object->name().c_str(), reloc_name.c_str());
9552       return 0;
9553     }
9554 }
9555
9556 // Scan the relocs during a relocatable link.
9557
9558 template<bool big_endian>
9559 void
9560 Target_arm<big_endian>::scan_relocatable_relocs(
9561     Symbol_table* symtab,
9562     Layout* layout,
9563     Sized_relobj_file<32, big_endian>* object,
9564     unsigned int data_shndx,
9565     unsigned int sh_type,
9566     const unsigned char* prelocs,
9567     size_t reloc_count,
9568     Output_section* output_section,
9569     bool needs_special_offset_handling,
9570     size_t local_symbol_count,
9571     const unsigned char* plocal_symbols,
9572     Relocatable_relocs* rr)
9573 {
9574   gold_assert(sh_type == elfcpp::SHT_REL);
9575
9576   typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
9577     Relocatable_size_for_reloc> Scan_relocatable_relocs;
9578
9579   gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
9580       Scan_relocatable_relocs>(
9581     symtab,
9582     layout,
9583     object,
9584     data_shndx,
9585     prelocs,
9586     reloc_count,
9587     output_section,
9588     needs_special_offset_handling,
9589     local_symbol_count,
9590     plocal_symbols,
9591     rr);
9592 }
9593
9594 // Emit relocations for a section.
9595
9596 template<bool big_endian>
9597 void
9598 Target_arm<big_endian>::relocate_relocs(
9599     const Relocate_info<32, big_endian>* relinfo,
9600     unsigned int sh_type,
9601     const unsigned char* prelocs,
9602     size_t reloc_count,
9603     Output_section* output_section,
9604     typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
9605     const Relocatable_relocs* rr,
9606     unsigned char* view,
9607     Arm_address view_address,
9608     section_size_type view_size,
9609     unsigned char* reloc_view,
9610     section_size_type reloc_view_size)
9611 {
9612   gold_assert(sh_type == elfcpp::SHT_REL);
9613
9614   gold::relocate_relocs<32, big_endian, elfcpp::SHT_REL>(
9615     relinfo,
9616     prelocs,
9617     reloc_count,
9618     output_section,
9619     offset_in_output_section,
9620     rr,
9621     view,
9622     view_address,
9623     view_size,
9624     reloc_view,
9625     reloc_view_size);
9626 }
9627
9628 // Perform target-specific processing in a relocatable link.  This is
9629 // only used if we use the relocation strategy RELOC_SPECIAL.
9630
9631 template<bool big_endian>
9632 void
9633 Target_arm<big_endian>::relocate_special_relocatable(
9634     const Relocate_info<32, big_endian>* relinfo,
9635     unsigned int sh_type,
9636     const unsigned char* preloc_in,
9637     size_t relnum,
9638     Output_section* output_section,
9639     typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
9640     unsigned char* view,
9641     elfcpp::Elf_types<32>::Elf_Addr view_address,
9642     section_size_type,
9643     unsigned char* preloc_out)
9644 {
9645   // We can only handle REL type relocation sections.
9646   gold_assert(sh_type == elfcpp::SHT_REL);
9647
9648   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
9649   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
9650     Reltype_write;
9651   const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
9652
9653   const Arm_relobj<big_endian>* object =
9654     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9655   const unsigned int local_count = object->local_symbol_count();
9656
9657   Reltype reloc(preloc_in);
9658   Reltype_write reloc_write(preloc_out);
9659
9660   elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
9661   const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9662   const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
9663
9664   const Arm_reloc_property* arp =
9665     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9666   gold_assert(arp != NULL);
9667
9668   // Get the new symbol index.
9669   // We only use RELOC_SPECIAL strategy in local relocations.
9670   gold_assert(r_sym < local_count);
9671
9672   // We are adjusting a section symbol.  We need to find
9673   // the symbol table index of the section symbol for
9674   // the output section corresponding to input section
9675   // in which this symbol is defined.
9676   bool is_ordinary;
9677   unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
9678   gold_assert(is_ordinary);
9679   Output_section* os = object->output_section(shndx);
9680   gold_assert(os != NULL);
9681   gold_assert(os->needs_symtab_index());
9682   unsigned int new_symndx = os->symtab_index();
9683
9684   // Get the new offset--the location in the output section where
9685   // this relocation should be applied.
9686
9687   Arm_address offset = reloc.get_r_offset();
9688   Arm_address new_offset;
9689   if (offset_in_output_section != invalid_address)
9690     new_offset = offset + offset_in_output_section;
9691   else
9692     {
9693       section_offset_type sot_offset =
9694           convert_types<section_offset_type, Arm_address>(offset);
9695       section_offset_type new_sot_offset =
9696           output_section->output_offset(object, relinfo->data_shndx,
9697                                         sot_offset);
9698       gold_assert(new_sot_offset != -1);
9699       new_offset = new_sot_offset;
9700     }
9701
9702   // In an object file, r_offset is an offset within the section.
9703   // In an executable or dynamic object, generated by
9704   // --emit-relocs, r_offset is an absolute address.
9705   if (!parameters->options().relocatable())
9706     {
9707       new_offset += view_address;
9708       if (offset_in_output_section != invalid_address)
9709         new_offset -= offset_in_output_section;
9710     }
9711
9712   reloc_write.put_r_offset(new_offset);
9713   reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
9714
9715   // Handle the reloc addend.
9716   // The relocation uses a section symbol in the input file.
9717   // We are adjusting it to use a section symbol in the output
9718   // file.  The input section symbol refers to some address in
9719   // the input section.  We need the relocation in the output
9720   // file to refer to that same address.  This adjustment to
9721   // the addend is the same calculation we use for a simple
9722   // absolute relocation for the input section symbol.
9723
9724   const Symbol_value<32>* psymval = object->local_symbol(r_sym);
9725
9726   // Handle THUMB bit.
9727   Symbol_value<32> symval;
9728   Arm_address thumb_bit =
9729      object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9730   if (thumb_bit != 0
9731       && arp->uses_thumb_bit()
9732       && ((psymval->value(object, 0) & 1) != 0))
9733     {
9734       Arm_address stripped_value =
9735         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9736       symval.set_output_value(stripped_value);
9737       psymval = &symval;
9738     }
9739
9740   unsigned char* paddend = view + offset;
9741   typename Arm_relocate_functions<big_endian>::Status reloc_status =
9742         Arm_relocate_functions<big_endian>::STATUS_OKAY;
9743   switch (r_type)
9744     {
9745     case elfcpp::R_ARM_ABS8:
9746       reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
9747                                                               psymval);
9748       break;
9749
9750     case elfcpp::R_ARM_ABS12:
9751       reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
9752                                                                psymval);
9753       break;
9754
9755     case elfcpp::R_ARM_ABS16:
9756       reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
9757                                                                psymval);
9758       break;
9759
9760     case elfcpp::R_ARM_THM_ABS5:
9761       reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
9762                                                                   object,
9763                                                                   psymval);
9764       break;
9765
9766     case elfcpp::R_ARM_MOVW_ABS_NC:
9767     case elfcpp::R_ARM_MOVW_PREL_NC:
9768     case elfcpp::R_ARM_MOVW_BREL_NC:
9769     case elfcpp::R_ARM_MOVW_BREL:
9770       reloc_status = Arm_relocate_functions<big_endian>::movw(
9771           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9772       break;
9773
9774     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9775     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9776     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9777     case elfcpp::R_ARM_THM_MOVW_BREL:
9778       reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
9779           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9780       break;
9781
9782     case elfcpp::R_ARM_THM_CALL:
9783     case elfcpp::R_ARM_THM_XPC22:
9784     case elfcpp::R_ARM_THM_JUMP24:
9785       reloc_status =
9786         Arm_relocate_functions<big_endian>::thumb_branch_common(
9787             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9788             false);
9789       break;
9790
9791     case elfcpp::R_ARM_PLT32:
9792     case elfcpp::R_ARM_CALL:
9793     case elfcpp::R_ARM_JUMP24:
9794     case elfcpp::R_ARM_XPC25:
9795       reloc_status =
9796         Arm_relocate_functions<big_endian>::arm_branch_common(
9797             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9798             false);
9799       break;
9800
9801     case elfcpp::R_ARM_THM_JUMP19:
9802       reloc_status =
9803         Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
9804                                                        psymval, 0, thumb_bit);
9805       break;
9806
9807     case elfcpp::R_ARM_THM_JUMP6:
9808       reloc_status =
9809         Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
9810                                                       0);
9811       break;
9812
9813     case elfcpp::R_ARM_THM_JUMP8:
9814       reloc_status =
9815         Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
9816                                                       0);
9817       break;
9818
9819     case elfcpp::R_ARM_THM_JUMP11:
9820       reloc_status =
9821         Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
9822                                                        0);
9823       break;
9824
9825     case elfcpp::R_ARM_PREL31:
9826       reloc_status =
9827         Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
9828                                                    thumb_bit);
9829       break;
9830
9831     case elfcpp::R_ARM_THM_PC8:
9832       reloc_status =
9833         Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
9834                                                     0);
9835       break;
9836
9837     case elfcpp::R_ARM_THM_PC12:
9838       reloc_status =
9839         Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
9840                                                      0);
9841       break;
9842
9843     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9844       reloc_status =
9845         Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
9846                                                       0, thumb_bit);
9847       break;
9848
9849     // These relocation truncate relocation results so we cannot handle them
9850     // in a relocatable link.
9851     case elfcpp::R_ARM_MOVT_ABS:
9852     case elfcpp::R_ARM_THM_MOVT_ABS:
9853     case elfcpp::R_ARM_MOVT_PREL:
9854     case elfcpp::R_ARM_MOVT_BREL:
9855     case elfcpp::R_ARM_THM_MOVT_PREL:
9856     case elfcpp::R_ARM_THM_MOVT_BREL:
9857     case elfcpp::R_ARM_ALU_PC_G0_NC:
9858     case elfcpp::R_ARM_ALU_PC_G0:
9859     case elfcpp::R_ARM_ALU_PC_G1_NC:
9860     case elfcpp::R_ARM_ALU_PC_G1:
9861     case elfcpp::R_ARM_ALU_PC_G2:
9862     case elfcpp::R_ARM_ALU_SB_G0_NC:
9863     case elfcpp::R_ARM_ALU_SB_G0:
9864     case elfcpp::R_ARM_ALU_SB_G1_NC:
9865     case elfcpp::R_ARM_ALU_SB_G1:
9866     case elfcpp::R_ARM_ALU_SB_G2:
9867     case elfcpp::R_ARM_LDR_PC_G0:
9868     case elfcpp::R_ARM_LDR_PC_G1:
9869     case elfcpp::R_ARM_LDR_PC_G2:
9870     case elfcpp::R_ARM_LDR_SB_G0:
9871     case elfcpp::R_ARM_LDR_SB_G1:
9872     case elfcpp::R_ARM_LDR_SB_G2:
9873     case elfcpp::R_ARM_LDRS_PC_G0:
9874     case elfcpp::R_ARM_LDRS_PC_G1:
9875     case elfcpp::R_ARM_LDRS_PC_G2:
9876     case elfcpp::R_ARM_LDRS_SB_G0:
9877     case elfcpp::R_ARM_LDRS_SB_G1:
9878     case elfcpp::R_ARM_LDRS_SB_G2:
9879     case elfcpp::R_ARM_LDC_PC_G0:
9880     case elfcpp::R_ARM_LDC_PC_G1:
9881     case elfcpp::R_ARM_LDC_PC_G2:
9882     case elfcpp::R_ARM_LDC_SB_G0:
9883     case elfcpp::R_ARM_LDC_SB_G1:
9884     case elfcpp::R_ARM_LDC_SB_G2:
9885       gold_error(_("cannot handle %s in a relocatable link"),
9886                  arp->name().c_str());
9887       break;
9888
9889     default:
9890       gold_unreachable();
9891     }
9892
9893   // Report any errors.
9894   switch (reloc_status)
9895     {
9896     case Arm_relocate_functions<big_endian>::STATUS_OKAY:
9897       break;
9898     case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
9899       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9900                              _("relocation overflow in %s"),
9901                              arp->name().c_str());
9902       break;
9903     case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
9904       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9905         _("unexpected opcode while processing relocation %s"),
9906         arp->name().c_str());
9907       break;
9908     default:
9909       gold_unreachable();
9910     }
9911 }
9912
9913 // Return the value to use for a dynamic symbol which requires special
9914 // treatment.  This is how we support equality comparisons of function
9915 // pointers across shared library boundaries, as described in the
9916 // processor specific ABI supplement.
9917
9918 template<bool big_endian>
9919 uint64_t
9920 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
9921 {
9922   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
9923   return this->plt_section()->address() + gsym->plt_offset();
9924 }
9925
9926 // Map platform-specific relocs to real relocs
9927 //
9928 template<bool big_endian>
9929 unsigned int
9930 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
9931 {
9932   switch (r_type)
9933     {
9934     case elfcpp::R_ARM_TARGET1:
9935       // This is either R_ARM_ABS32 or R_ARM_REL32;
9936       return elfcpp::R_ARM_ABS32;
9937
9938     case elfcpp::R_ARM_TARGET2:
9939       // This can be any reloc type but usually is R_ARM_GOT_PREL
9940       return elfcpp::R_ARM_GOT_PREL;
9941
9942     default:
9943       return r_type;
9944     }
9945 }
9946
9947 // Whether if two EABI versions V1 and V2 are compatible.
9948
9949 template<bool big_endian>
9950 bool
9951 Target_arm<big_endian>::are_eabi_versions_compatible(
9952     elfcpp::Elf_Word v1,
9953     elfcpp::Elf_Word v2)
9954 {
9955   // v4 and v5 are the same spec before and after it was released,
9956   // so allow mixing them.
9957   if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
9958       || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
9959       || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
9960     return true;
9961
9962   return v1 == v2;
9963 }
9964
9965 // Combine FLAGS from an input object called NAME and the processor-specific
9966 // flags in the ELF header of the output.  Much of this is adapted from the
9967 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
9968 // in bfd/elf32-arm.c.
9969
9970 template<bool big_endian>
9971 void
9972 Target_arm<big_endian>::merge_processor_specific_flags(
9973     const std::string& name,
9974     elfcpp::Elf_Word flags)
9975 {
9976   if (this->are_processor_specific_flags_set())
9977     {
9978       elfcpp::Elf_Word out_flags = this->processor_specific_flags();
9979
9980       // Nothing to merge if flags equal to those in output.
9981       if (flags == out_flags)
9982         return;
9983
9984       // Complain about various flag mismatches.
9985       elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
9986       elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
9987       if (!this->are_eabi_versions_compatible(version1, version2)
9988           && parameters->options().warn_mismatch())
9989         gold_error(_("Source object %s has EABI version %d but output has "
9990                      "EABI version %d."),
9991                    name.c_str(),
9992                    (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
9993                    (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
9994     }
9995   else
9996     {
9997       // If the input is the default architecture and had the default
9998       // flags then do not bother setting the flags for the output
9999       // architecture, instead allow future merges to do this.  If no
10000       // future merges ever set these flags then they will retain their
10001       // uninitialised values, which surprise surprise, correspond
10002       // to the default values.
10003       if (flags == 0)
10004         return;
10005
10006       // This is the first time, just copy the flags.
10007       // We only copy the EABI version for now.
10008       this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
10009     }
10010 }
10011
10012 // Adjust ELF file header.
10013 template<bool big_endian>
10014 void
10015 Target_arm<big_endian>::do_adjust_elf_header(
10016     unsigned char* view,
10017     int len)
10018 {
10019   gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
10020
10021   elfcpp::Ehdr<32, big_endian> ehdr(view);
10022   elfcpp::Elf_Word flags = this->processor_specific_flags();
10023   unsigned char e_ident[elfcpp::EI_NIDENT];
10024   memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
10025
10026   if (elfcpp::arm_eabi_version(flags)
10027       == elfcpp::EF_ARM_EABI_UNKNOWN)
10028     e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
10029   else
10030     e_ident[elfcpp::EI_OSABI] = 0;
10031   e_ident[elfcpp::EI_ABIVERSION] = 0;
10032
10033   // FIXME: Do EF_ARM_BE8 adjustment.
10034
10035   // If we're working in EABI_VER5, set the hard/soft float ABI flags
10036   // as appropriate.
10037   if (elfcpp::arm_eabi_version(flags) == elfcpp::EF_ARM_EABI_VER5)
10038   {
10039     elfcpp::Elf_Half type = ehdr.get_e_type();
10040     if (type == elfcpp::ET_EXEC || type == elfcpp::ET_DYN)
10041       {
10042         Object_attribute* attr = this->get_aeabi_object_attribute(elfcpp::Tag_ABI_VFP_args);
10043         if (attr->int_value())
10044           flags |= elfcpp::EF_ARM_ABI_FLOAT_HARD;
10045         else
10046           flags |= elfcpp::EF_ARM_ABI_FLOAT_SOFT;
10047         this->set_processor_specific_flags(flags);
10048       }
10049   }
10050   elfcpp::Ehdr_write<32, big_endian> oehdr(view);
10051   oehdr.put_e_ident(e_ident);
10052 }
10053
10054 // do_make_elf_object to override the same function in the base class.
10055 // We need to use a target-specific sub-class of
10056 // Sized_relobj_file<32, big_endian> to store ARM specific information.
10057 // Hence we need to have our own ELF object creation.
10058
10059 template<bool big_endian>
10060 Object*
10061 Target_arm<big_endian>::do_make_elf_object(
10062     const std::string& name,
10063     Input_file* input_file,
10064     off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
10065 {
10066   int et = ehdr.get_e_type();
10067   // ET_EXEC files are valid input for --just-symbols/-R,
10068   // and we treat them as relocatable objects.
10069   if (et == elfcpp::ET_REL
10070       || (et == elfcpp::ET_EXEC && input_file->just_symbols()))
10071     {
10072       Arm_relobj<big_endian>* obj =
10073         new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
10074       obj->setup();
10075       return obj;
10076     }
10077   else if (et == elfcpp::ET_DYN)
10078     {
10079       Sized_dynobj<32, big_endian>* obj =
10080         new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
10081       obj->setup();
10082       return obj;
10083     }
10084   else
10085     {
10086       gold_error(_("%s: unsupported ELF file type %d"),
10087                  name.c_str(), et);
10088       return NULL;
10089     }
10090 }
10091
10092 // Read the architecture from the Tag_also_compatible_with attribute, if any.
10093 // Returns -1 if no architecture could be read.
10094 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
10095
10096 template<bool big_endian>
10097 int
10098 Target_arm<big_endian>::get_secondary_compatible_arch(
10099     const Attributes_section_data* pasd)
10100 {
10101   const Object_attribute* known_attributes =
10102     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10103
10104   // Note: the tag and its argument below are uleb128 values, though
10105   // currently-defined values fit in one byte for each.
10106   const std::string& sv =
10107     known_attributes[elfcpp::Tag_also_compatible_with].string_value();
10108   if (sv.size() == 2
10109       && sv.data()[0] == elfcpp::Tag_CPU_arch
10110       && (sv.data()[1] & 128) != 128)
10111    return sv.data()[1];
10112
10113   // This tag is "safely ignorable", so don't complain if it looks funny.
10114   return -1;
10115 }
10116
10117 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10118 // The tag is removed if ARCH is -1.
10119 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10120
10121 template<bool big_endian>
10122 void
10123 Target_arm<big_endian>::set_secondary_compatible_arch(
10124     Attributes_section_data* pasd,
10125     int arch)
10126 {
10127   Object_attribute* known_attributes =
10128     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10129
10130   if (arch == -1)
10131     {
10132       known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10133       return;
10134     }
10135
10136   // Note: the tag and its argument below are uleb128 values, though
10137   // currently-defined values fit in one byte for each.
10138   char sv[3];
10139   sv[0] = elfcpp::Tag_CPU_arch;
10140   gold_assert(arch != 0);
10141   sv[1] = arch;
10142   sv[2] = '\0';
10143
10144   known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10145 }
10146
10147 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10148 // into account.
10149 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10150
10151 template<bool big_endian>
10152 int
10153 Target_arm<big_endian>::tag_cpu_arch_combine(
10154     const char* name,
10155     int oldtag,
10156     int* secondary_compat_out,
10157     int newtag,
10158     int secondary_compat)
10159 {
10160 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10161   static const int v6t2[] =
10162     {
10163       T(V6T2),   // PRE_V4.
10164       T(V6T2),   // V4.
10165       T(V6T2),   // V4T.
10166       T(V6T2),   // V5T.
10167       T(V6T2),   // V5TE.
10168       T(V6T2),   // V5TEJ.
10169       T(V6T2),   // V6.
10170       T(V7),     // V6KZ.
10171       T(V6T2)    // V6T2.
10172     };
10173   static const int v6k[] =
10174     {
10175       T(V6K),    // PRE_V4.
10176       T(V6K),    // V4.
10177       T(V6K),    // V4T.
10178       T(V6K),    // V5T.
10179       T(V6K),    // V5TE.
10180       T(V6K),    // V5TEJ.
10181       T(V6K),    // V6.
10182       T(V6KZ),   // V6KZ.
10183       T(V7),     // V6T2.
10184       T(V6K)     // V6K.
10185     };
10186   static const int v7[] =
10187     {
10188       T(V7),     // PRE_V4.
10189       T(V7),     // V4.
10190       T(V7),     // V4T.
10191       T(V7),     // V5T.
10192       T(V7),     // V5TE.
10193       T(V7),     // V5TEJ.
10194       T(V7),     // V6.
10195       T(V7),     // V6KZ.
10196       T(V7),     // V6T2.
10197       T(V7),     // V6K.
10198       T(V7)      // V7.
10199     };
10200   static const int v6_m[] =
10201     {
10202       -1,        // PRE_V4.
10203       -1,        // V4.
10204       T(V6K),    // V4T.
10205       T(V6K),    // V5T.
10206       T(V6K),    // V5TE.
10207       T(V6K),    // V5TEJ.
10208       T(V6K),    // V6.
10209       T(V6KZ),   // V6KZ.
10210       T(V7),     // V6T2.
10211       T(V6K),    // V6K.
10212       T(V7),     // V7.
10213       T(V6_M)    // V6_M.
10214     };
10215   static const int v6s_m[] =
10216     {
10217       -1,        // PRE_V4.
10218       -1,        // V4.
10219       T(V6K),    // V4T.
10220       T(V6K),    // V5T.
10221       T(V6K),    // V5TE.
10222       T(V6K),    // V5TEJ.
10223       T(V6K),    // V6.
10224       T(V6KZ),   // V6KZ.
10225       T(V7),     // V6T2.
10226       T(V6K),    // V6K.
10227       T(V7),     // V7.
10228       T(V6S_M),  // V6_M.
10229       T(V6S_M)   // V6S_M.
10230     };
10231   static const int v7e_m[] =
10232     {
10233       -1,       // PRE_V4.
10234       -1,       // V4.
10235       T(V7E_M), // V4T.
10236       T(V7E_M), // V5T.
10237       T(V7E_M), // V5TE.
10238       T(V7E_M), // V5TEJ.
10239       T(V7E_M), // V6.
10240       T(V7E_M), // V6KZ.
10241       T(V7E_M), // V6T2.
10242       T(V7E_M), // V6K.
10243       T(V7E_M), // V7.
10244       T(V7E_M), // V6_M.
10245       T(V7E_M), // V6S_M.
10246       T(V7E_M)  // V7E_M.
10247     };
10248   static const int v4t_plus_v6_m[] =
10249     {
10250       -1,               // PRE_V4.
10251       -1,               // V4.
10252       T(V4T),           // V4T.
10253       T(V5T),           // V5T.
10254       T(V5TE),          // V5TE.
10255       T(V5TEJ),         // V5TEJ.
10256       T(V6),            // V6.
10257       T(V6KZ),          // V6KZ.
10258       T(V6T2),          // V6T2.
10259       T(V6K),           // V6K.
10260       T(V7),            // V7.
10261       T(V6_M),          // V6_M.
10262       T(V6S_M),         // V6S_M.
10263       T(V7E_M),         // V7E_M.
10264       T(V4T_PLUS_V6_M)  // V4T plus V6_M.
10265     };
10266   static const int* comb[] =
10267     {
10268       v6t2,
10269       v6k,
10270       v7,
10271       v6_m,
10272       v6s_m,
10273       v7e_m,
10274       // Pseudo-architecture.
10275       v4t_plus_v6_m
10276     };
10277
10278   // Check we've not got a higher architecture than we know about.
10279
10280   if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
10281     {
10282       gold_error(_("%s: unknown CPU architecture"), name);
10283       return -1;
10284     }
10285
10286   // Override old tag if we have a Tag_also_compatible_with on the output.
10287
10288   if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10289       || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10290     oldtag = T(V4T_PLUS_V6_M);
10291
10292   // And override the new tag if we have a Tag_also_compatible_with on the
10293   // input.
10294
10295   if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10296       || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10297     newtag = T(V4T_PLUS_V6_M);
10298
10299   // Architectures before V6KZ add features monotonically.
10300   int tagh = std::max(oldtag, newtag);
10301   if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10302     return tagh;
10303
10304   int tagl = std::min(oldtag, newtag);
10305   int result = comb[tagh - T(V6T2)][tagl];
10306
10307   // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10308   // as the canonical version.
10309   if (result == T(V4T_PLUS_V6_M))
10310     {
10311       result = T(V4T);
10312       *secondary_compat_out = T(V6_M);
10313     }
10314   else
10315     *secondary_compat_out = -1;
10316
10317   if (result == -1)
10318     {
10319       gold_error(_("%s: conflicting CPU architectures %d/%d"),
10320                  name, oldtag, newtag);
10321       return -1;
10322     }
10323
10324   return result;
10325 #undef T
10326 }
10327
10328 // Helper to print AEABI enum tag value.
10329
10330 template<bool big_endian>
10331 std::string
10332 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10333 {
10334   static const char* aeabi_enum_names[] =
10335     { "", "variable-size", "32-bit", "" };
10336   const size_t aeabi_enum_names_size =
10337     sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10338
10339   if (value < aeabi_enum_names_size)
10340     return std::string(aeabi_enum_names[value]);
10341   else
10342     {
10343       char buffer[100];
10344       sprintf(buffer, "<unknown value %u>", value);
10345       return std::string(buffer);
10346     }
10347 }
10348
10349 // Return the string value to store in TAG_CPU_name.
10350
10351 template<bool big_endian>
10352 std::string
10353 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10354 {
10355   static const char* name_table[] = {
10356     // These aren't real CPU names, but we can't guess
10357     // that from the architecture version alone.
10358    "Pre v4",
10359    "ARM v4",
10360    "ARM v4T",
10361    "ARM v5T",
10362    "ARM v5TE",
10363    "ARM v5TEJ",
10364    "ARM v6",
10365    "ARM v6KZ",
10366    "ARM v6T2",
10367    "ARM v6K",
10368    "ARM v7",
10369    "ARM v6-M",
10370    "ARM v6S-M",
10371    "ARM v7E-M"
10372  };
10373  const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10374
10375   if (value < name_table_size)
10376     return std::string(name_table[value]);
10377   else
10378     {
10379       char buffer[100];
10380       sprintf(buffer, "<unknown CPU value %u>", value);
10381       return std::string(buffer);
10382     }
10383 }
10384
10385 // Merge object attributes from input file called NAME with those of the
10386 // output.  The input object attributes are in the object pointed by PASD.
10387
10388 template<bool big_endian>
10389 void
10390 Target_arm<big_endian>::merge_object_attributes(
10391     const char* name,
10392     const Attributes_section_data* pasd)
10393 {
10394   // Return if there is no attributes section data.
10395   if (pasd == NULL)
10396     return;
10397
10398   // If output has no object attributes, just copy.
10399   const int vendor = Object_attribute::OBJ_ATTR_PROC;
10400   if (this->attributes_section_data_ == NULL)
10401     {
10402       this->attributes_section_data_ = new Attributes_section_data(*pasd);
10403       Object_attribute* out_attr =
10404         this->attributes_section_data_->known_attributes(vendor);
10405
10406       // We do not output objects with Tag_MPextension_use_legacy - we move
10407       //  the attribute's value to Tag_MPextension_use.  */
10408       if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10409         {
10410           if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10411               && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10412                 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10413             {
10414               gold_error(_("%s has both the current and legacy "
10415                            "Tag_MPextension_use attributes"),
10416                          name);
10417             }
10418
10419           out_attr[elfcpp::Tag_MPextension_use] =
10420             out_attr[elfcpp::Tag_MPextension_use_legacy];
10421           out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10422           out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10423         }
10424
10425       return;
10426     }
10427
10428   const Object_attribute* in_attr = pasd->known_attributes(vendor);
10429   Object_attribute* out_attr =
10430     this->attributes_section_data_->known_attributes(vendor);
10431
10432   // This needs to happen before Tag_ABI_FP_number_model is merged.  */
10433   if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10434       != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
10435     {
10436       // Ignore mismatches if the object doesn't use floating point.  */
10437       if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
10438         out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10439             in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10440       else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
10441                && parameters->options().warn_mismatch())
10442         gold_error(_("%s uses VFP register arguments, output does not"),
10443                    name);
10444     }
10445
10446   for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10447     {
10448       // Merge this attribute with existing attributes.
10449       switch (i)
10450         {
10451         case elfcpp::Tag_CPU_raw_name:
10452         case elfcpp::Tag_CPU_name:
10453           // These are merged after Tag_CPU_arch.
10454           break;
10455
10456         case elfcpp::Tag_ABI_optimization_goals:
10457         case elfcpp::Tag_ABI_FP_optimization_goals:
10458           // Use the first value seen.
10459           break;
10460
10461         case elfcpp::Tag_CPU_arch:
10462           {
10463             unsigned int saved_out_attr = out_attr->int_value();
10464             // Merge Tag_CPU_arch and Tag_also_compatible_with.
10465             int secondary_compat =
10466               this->get_secondary_compatible_arch(pasd);
10467             int secondary_compat_out =
10468               this->get_secondary_compatible_arch(
10469                   this->attributes_section_data_);
10470             out_attr[i].set_int_value(
10471                 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10472                                      &secondary_compat_out,
10473                                      in_attr[i].int_value(),
10474                                      secondary_compat));
10475             this->set_secondary_compatible_arch(this->attributes_section_data_,
10476                                                 secondary_compat_out);
10477
10478             // Merge Tag_CPU_name and Tag_CPU_raw_name.
10479             if (out_attr[i].int_value() == saved_out_attr)
10480               ; // Leave the names alone.
10481             else if (out_attr[i].int_value() == in_attr[i].int_value())
10482               {
10483                 // The output architecture has been changed to match the
10484                 // input architecture.  Use the input names.
10485                 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10486                     in_attr[elfcpp::Tag_CPU_name].string_value());
10487                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10488                     in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10489               }
10490             else
10491               {
10492                 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10493                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10494               }
10495
10496             // If we still don't have a value for Tag_CPU_name,
10497             // make one up now.  Tag_CPU_raw_name remains blank.
10498             if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10499               {
10500                 const std::string cpu_name =
10501                   this->tag_cpu_name_value(out_attr[i].int_value());
10502                 // FIXME:  If we see an unknown CPU, this will be set
10503                 // to "<unknown CPU n>", where n is the attribute value.
10504                 // This is different from BFD, which leaves the name alone.
10505                 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10506               }
10507           }
10508           break;
10509
10510         case elfcpp::Tag_ARM_ISA_use:
10511         case elfcpp::Tag_THUMB_ISA_use:
10512         case elfcpp::Tag_WMMX_arch:
10513         case elfcpp::Tag_Advanced_SIMD_arch:
10514           // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10515         case elfcpp::Tag_ABI_FP_rounding:
10516         case elfcpp::Tag_ABI_FP_exceptions:
10517         case elfcpp::Tag_ABI_FP_user_exceptions:
10518         case elfcpp::Tag_ABI_FP_number_model:
10519         case elfcpp::Tag_VFP_HP_extension:
10520         case elfcpp::Tag_CPU_unaligned_access:
10521         case elfcpp::Tag_T2EE_use:
10522         case elfcpp::Tag_Virtualization_use:
10523         case elfcpp::Tag_MPextension_use:
10524           // Use the largest value specified.
10525           if (in_attr[i].int_value() > out_attr[i].int_value())
10526             out_attr[i].set_int_value(in_attr[i].int_value());
10527           break;
10528
10529         case elfcpp::Tag_ABI_align8_preserved:
10530         case elfcpp::Tag_ABI_PCS_RO_data:
10531           // Use the smallest value specified.
10532           if (in_attr[i].int_value() < out_attr[i].int_value())
10533             out_attr[i].set_int_value(in_attr[i].int_value());
10534           break;
10535
10536         case elfcpp::Tag_ABI_align8_needed:
10537           if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10538               && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10539                   || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10540                       == 0)))
10541             {
10542               // This error message should be enabled once all non-conforming
10543               // binaries in the toolchain have had the attributes set
10544               // properly.
10545               // gold_error(_("output 8-byte data alignment conflicts with %s"),
10546               //            name);
10547             }
10548           // Fall through.
10549         case elfcpp::Tag_ABI_FP_denormal:
10550         case elfcpp::Tag_ABI_PCS_GOT_use:
10551           {
10552             // These tags have 0 = don't care, 1 = strong requirement,
10553             // 2 = weak requirement.
10554             static const int order_021[3] = {0, 2, 1};
10555
10556             // Use the "greatest" from the sequence 0, 2, 1, or the largest
10557             // value if greater than 2 (for future-proofing).
10558             if ((in_attr[i].int_value() > 2
10559                  && in_attr[i].int_value() > out_attr[i].int_value())
10560                 || (in_attr[i].int_value() <= 2
10561                     && out_attr[i].int_value() <= 2
10562                     && (order_021[in_attr[i].int_value()]
10563                         > order_021[out_attr[i].int_value()])))
10564               out_attr[i].set_int_value(in_attr[i].int_value());
10565           }
10566           break;
10567
10568         case elfcpp::Tag_CPU_arch_profile:
10569           if (out_attr[i].int_value() != in_attr[i].int_value())
10570             {
10571               // 0 will merge with anything.
10572               // 'A' and 'S' merge to 'A'.
10573               // 'R' and 'S' merge to 'R'.
10574               // 'M' and 'A|R|S' is an error.
10575               if (out_attr[i].int_value() == 0
10576                   || (out_attr[i].int_value() == 'S'
10577                       && (in_attr[i].int_value() == 'A'
10578                           || in_attr[i].int_value() == 'R')))
10579                 out_attr[i].set_int_value(in_attr[i].int_value());
10580               else if (in_attr[i].int_value() == 0
10581                        || (in_attr[i].int_value() == 'S'
10582                            && (out_attr[i].int_value() == 'A'
10583                                || out_attr[i].int_value() == 'R')))
10584                 ; // Do nothing.
10585               else if (parameters->options().warn_mismatch())
10586                 {
10587                   gold_error
10588                     (_("conflicting architecture profiles %c/%c"),
10589                      in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10590                      out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10591                 }
10592             }
10593           break;
10594         case elfcpp::Tag_VFP_arch:
10595             {
10596               static const struct
10597               {
10598                   int ver;
10599                   int regs;
10600               } vfp_versions[7] =
10601                 {
10602                   {0, 0},
10603                   {1, 16},
10604                   {2, 16},
10605                   {3, 32},
10606                   {3, 16},
10607                   {4, 32},
10608                   {4, 16}
10609                 };
10610
10611               // Values greater than 6 aren't defined, so just pick the
10612               // biggest.
10613               if (in_attr[i].int_value() > 6
10614                   && in_attr[i].int_value() > out_attr[i].int_value())
10615                 {
10616                   *out_attr = *in_attr;
10617                   break;
10618                 }
10619               // The output uses the superset of input features
10620               // (ISA version) and registers.
10621               int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10622                                  vfp_versions[out_attr[i].int_value()].ver);
10623               int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10624                                   vfp_versions[out_attr[i].int_value()].regs);
10625               // This assumes all possible supersets are also a valid
10626               // options.
10627               int newval;
10628               for (newval = 6; newval > 0; newval--)
10629                 {
10630                   if (regs == vfp_versions[newval].regs
10631                       && ver == vfp_versions[newval].ver)
10632                     break;
10633                 }
10634               out_attr[i].set_int_value(newval);
10635             }
10636           break;
10637         case elfcpp::Tag_PCS_config:
10638           if (out_attr[i].int_value() == 0)
10639             out_attr[i].set_int_value(in_attr[i].int_value());
10640           else if (in_attr[i].int_value() != 0
10641                    && out_attr[i].int_value() != 0
10642                    && parameters->options().warn_mismatch())
10643             {
10644               // It's sometimes ok to mix different configs, so this is only
10645               // a warning.
10646               gold_warning(_("%s: conflicting platform configuration"), name);
10647             }
10648           break;
10649         case elfcpp::Tag_ABI_PCS_R9_use:
10650           if (in_attr[i].int_value() != out_attr[i].int_value()
10651               && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10652               && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10653               && parameters->options().warn_mismatch())
10654             {
10655               gold_error(_("%s: conflicting use of R9"), name);
10656             }
10657           if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10658             out_attr[i].set_int_value(in_attr[i].int_value());
10659           break;
10660         case elfcpp::Tag_ABI_PCS_RW_data:
10661           if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10662               && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10663                   != elfcpp::AEABI_R9_SB)
10664               && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10665                   != elfcpp::AEABI_R9_unused)
10666               && parameters->options().warn_mismatch())
10667             {
10668               gold_error(_("%s: SB relative addressing conflicts with use "
10669                            "of R9"),
10670                            name);
10671             }
10672           // Use the smallest value specified.
10673           if (in_attr[i].int_value() < out_attr[i].int_value())
10674             out_attr[i].set_int_value(in_attr[i].int_value());
10675           break;
10676         case elfcpp::Tag_ABI_PCS_wchar_t:
10677           if (out_attr[i].int_value()
10678               && in_attr[i].int_value()
10679               && out_attr[i].int_value() != in_attr[i].int_value()
10680               && parameters->options().warn_mismatch()
10681               && parameters->options().wchar_size_warning())
10682             {
10683               gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10684                              "use %u-byte wchar_t; use of wchar_t values "
10685                              "across objects may fail"),
10686                            name, in_attr[i].int_value(),
10687                            out_attr[i].int_value());
10688             }
10689           else if (in_attr[i].int_value() && !out_attr[i].int_value())
10690             out_attr[i].set_int_value(in_attr[i].int_value());
10691           break;
10692         case elfcpp::Tag_ABI_enum_size:
10693           if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10694             {
10695               if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10696                   || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10697                 {
10698                   // The existing object is compatible with anything.
10699                   // Use whatever requirements the new object has.
10700                   out_attr[i].set_int_value(in_attr[i].int_value());
10701                 }
10702               else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10703                        && out_attr[i].int_value() != in_attr[i].int_value()
10704                        && parameters->options().warn_mismatch()
10705                        && parameters->options().enum_size_warning())
10706                 {
10707                   unsigned int in_value = in_attr[i].int_value();
10708                   unsigned int out_value = out_attr[i].int_value();
10709                   gold_warning(_("%s uses %s enums yet the output is to use "
10710                                  "%s enums; use of enum values across objects "
10711                                  "may fail"),
10712                                name,
10713                                this->aeabi_enum_name(in_value).c_str(),
10714                                this->aeabi_enum_name(out_value).c_str());
10715                 }
10716             }
10717           break;
10718         case elfcpp::Tag_ABI_VFP_args:
10719           // Already done.
10720           break;
10721         case elfcpp::Tag_ABI_WMMX_args:
10722           if (in_attr[i].int_value() != out_attr[i].int_value()
10723               && parameters->options().warn_mismatch())
10724             {
10725               gold_error(_("%s uses iWMMXt register arguments, output does "
10726                            "not"),
10727                          name);
10728             }
10729           break;
10730         case Object_attribute::Tag_compatibility:
10731           // Merged in target-independent code.
10732           break;
10733         case elfcpp::Tag_ABI_HardFP_use:
10734           // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10735           if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10736               || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10737             out_attr[i].set_int_value(3);
10738           else if (in_attr[i].int_value() > out_attr[i].int_value())
10739             out_attr[i].set_int_value(in_attr[i].int_value());
10740           break;
10741         case elfcpp::Tag_ABI_FP_16bit_format:
10742           if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10743             {
10744               if (in_attr[i].int_value() != out_attr[i].int_value()
10745                   && parameters->options().warn_mismatch())
10746                 gold_error(_("fp16 format mismatch between %s and output"),
10747                            name);
10748             }
10749           if (in_attr[i].int_value() != 0)
10750             out_attr[i].set_int_value(in_attr[i].int_value());
10751           break;
10752
10753         case elfcpp::Tag_DIV_use:
10754           // This tag is set to zero if we can use UDIV and SDIV in Thumb
10755           // mode on a v7-M or v7-R CPU; to one if we can not use UDIV or
10756           // SDIV at all; and to two if we can use UDIV or SDIV on a v7-A
10757           // CPU.  We will merge as follows: If the input attribute's value
10758           // is one then the output attribute's value remains unchanged.  If
10759           // the input attribute's value is zero or two then if the output
10760           // attribute's value is one the output value is set to the input
10761           // value, otherwise the output value must be the same as the
10762           // inputs.  */
10763           if (in_attr[i].int_value() != 1 && out_attr[i].int_value() != 1)
10764             {
10765               if (in_attr[i].int_value() != out_attr[i].int_value())
10766                 {
10767                   gold_error(_("DIV usage mismatch between %s and output"),
10768                              name);
10769                 }
10770             }
10771
10772           if (in_attr[i].int_value() != 1)
10773             out_attr[i].set_int_value(in_attr[i].int_value());
10774
10775           break;
10776
10777         case elfcpp::Tag_MPextension_use_legacy:
10778           // We don't output objects with Tag_MPextension_use_legacy - we
10779           // move the value to Tag_MPextension_use.
10780           if (in_attr[i].int_value() != 0
10781               && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10782             {
10783               if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10784                   != in_attr[i].int_value())
10785                 {
10786                   gold_error(_("%s has has both the current and legacy "
10787                                "Tag_MPextension_use attributes"),
10788                              name);
10789                 }
10790             }
10791
10792           if (in_attr[i].int_value()
10793               > out_attr[elfcpp::Tag_MPextension_use].int_value())
10794             out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10795
10796           break;
10797
10798         case elfcpp::Tag_nodefaults:
10799           // This tag is set if it exists, but the value is unused (and is
10800           // typically zero).  We don't actually need to do anything here -
10801           // the merge happens automatically when the type flags are merged
10802           // below.
10803           break;
10804         case elfcpp::Tag_also_compatible_with:
10805           // Already done in Tag_CPU_arch.
10806           break;
10807         case elfcpp::Tag_conformance:
10808           // Keep the attribute if it matches.  Throw it away otherwise.
10809           // No attribute means no claim to conform.
10810           if (in_attr[i].string_value() != out_attr[i].string_value())
10811             out_attr[i].set_string_value("");
10812           break;
10813
10814         default:
10815           {
10816             const char* err_object = NULL;
10817
10818             // The "known_obj_attributes" table does contain some undefined
10819             // attributes.  Ensure that there are unused.
10820             if (out_attr[i].int_value() != 0
10821                 || out_attr[i].string_value() != "")
10822               err_object = "output";
10823             else if (in_attr[i].int_value() != 0
10824                      || in_attr[i].string_value() != "")
10825               err_object = name;
10826
10827             if (err_object != NULL
10828                 && parameters->options().warn_mismatch())
10829               {
10830                 // Attribute numbers >=64 (mod 128) can be safely ignored.
10831                 if ((i & 127) < 64)
10832                   gold_error(_("%s: unknown mandatory EABI object attribute "
10833                                "%d"),
10834                              err_object, i);
10835                 else
10836                   gold_warning(_("%s: unknown EABI object attribute %d"),
10837                                err_object, i);
10838               }
10839
10840             // Only pass on attributes that match in both inputs.
10841             if (!in_attr[i].matches(out_attr[i]))
10842               {
10843                 out_attr[i].set_int_value(0);
10844                 out_attr[i].set_string_value("");
10845               }
10846           }
10847         }
10848
10849       // If out_attr was copied from in_attr then it won't have a type yet.
10850       if (in_attr[i].type() && !out_attr[i].type())
10851         out_attr[i].set_type(in_attr[i].type());
10852     }
10853
10854   // Merge Tag_compatibility attributes and any common GNU ones.
10855   this->attributes_section_data_->merge(name, pasd);
10856
10857   // Check for any attributes not known on ARM.
10858   typedef Vendor_object_attributes::Other_attributes Other_attributes;
10859   const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10860   Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10861   Other_attributes* out_other_attributes =
10862     this->attributes_section_data_->other_attributes(vendor);
10863   Other_attributes::iterator out_iter = out_other_attributes->begin();
10864
10865   while (in_iter != in_other_attributes->end()
10866          || out_iter != out_other_attributes->end())
10867     {
10868       const char* err_object = NULL;
10869       int err_tag = 0;
10870
10871       // The tags for each list are in numerical order.
10872       // If the tags are equal, then merge.
10873       if (out_iter != out_other_attributes->end()
10874           && (in_iter == in_other_attributes->end()
10875               || in_iter->first > out_iter->first))
10876         {
10877           // This attribute only exists in output.  We can't merge, and we
10878           // don't know what the tag means, so delete it.
10879           err_object = "output";
10880           err_tag = out_iter->first;
10881           int saved_tag = out_iter->first;
10882           delete out_iter->second;
10883           out_other_attributes->erase(out_iter);
10884           out_iter = out_other_attributes->upper_bound(saved_tag);
10885         }
10886       else if (in_iter != in_other_attributes->end()
10887                && (out_iter != out_other_attributes->end()
10888                    || in_iter->first < out_iter->first))
10889         {
10890           // This attribute only exists in input. We can't merge, and we
10891           // don't know what the tag means, so ignore it.
10892           err_object = name;
10893           err_tag = in_iter->first;
10894           ++in_iter;
10895         }
10896       else // The tags are equal.
10897         {
10898           // As present, all attributes in the list are unknown, and
10899           // therefore can't be merged meaningfully.
10900           err_object = "output";
10901           err_tag = out_iter->first;
10902
10903           //  Only pass on attributes that match in both inputs.
10904           if (!in_iter->second->matches(*(out_iter->second)))
10905             {
10906               // No match.  Delete the attribute.
10907               int saved_tag = out_iter->first;
10908               delete out_iter->second;
10909               out_other_attributes->erase(out_iter);
10910               out_iter = out_other_attributes->upper_bound(saved_tag);
10911             }
10912           else
10913             {
10914               // Matched.  Keep the attribute and move to the next.
10915               ++out_iter;
10916               ++in_iter;
10917             }
10918         }
10919
10920       if (err_object && parameters->options().warn_mismatch())
10921         {
10922           // Attribute numbers >=64 (mod 128) can be safely ignored.  */
10923           if ((err_tag & 127) < 64)
10924             {
10925               gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10926                          err_object, err_tag);
10927             }
10928           else
10929             {
10930               gold_warning(_("%s: unknown EABI object attribute %d"),
10931                            err_object, err_tag);
10932             }
10933         }
10934     }
10935 }
10936
10937 // Stub-generation methods for Target_arm.
10938
10939 // Make a new Arm_input_section object.
10940
10941 template<bool big_endian>
10942 Arm_input_section<big_endian>*
10943 Target_arm<big_endian>::new_arm_input_section(
10944     Relobj* relobj,
10945     unsigned int shndx)
10946 {
10947   Section_id sid(relobj, shndx);
10948
10949   Arm_input_section<big_endian>* arm_input_section =
10950     new Arm_input_section<big_endian>(relobj, shndx);
10951   arm_input_section->init();
10952
10953   // Register new Arm_input_section in map for look-up.
10954   std::pair<typename Arm_input_section_map::iterator, bool> ins =
10955     this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
10956
10957   // Make sure that it we have not created another Arm_input_section
10958   // for this input section already.
10959   gold_assert(ins.second);
10960
10961   return arm_input_section;
10962 }
10963
10964 // Find the Arm_input_section object corresponding to the SHNDX-th input
10965 // section of RELOBJ.
10966
10967 template<bool big_endian>
10968 Arm_input_section<big_endian>*
10969 Target_arm<big_endian>::find_arm_input_section(
10970     Relobj* relobj,
10971     unsigned int shndx) const
10972 {
10973   Section_id sid(relobj, shndx);
10974   typename Arm_input_section_map::const_iterator p =
10975     this->arm_input_section_map_.find(sid);
10976   return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
10977 }
10978
10979 // Make a new stub table.
10980
10981 template<bool big_endian>
10982 Stub_table<big_endian>*
10983 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
10984 {
10985   Stub_table<big_endian>* stub_table =
10986     new Stub_table<big_endian>(owner);
10987   this->stub_tables_.push_back(stub_table);
10988
10989   stub_table->set_address(owner->address() + owner->data_size());
10990   stub_table->set_file_offset(owner->offset() + owner->data_size());
10991   stub_table->finalize_data_size();
10992
10993   return stub_table;
10994 }
10995
10996 // Scan a relocation for stub generation.
10997
10998 template<bool big_endian>
10999 void
11000 Target_arm<big_endian>::scan_reloc_for_stub(
11001     const Relocate_info<32, big_endian>* relinfo,
11002     unsigned int r_type,
11003     const Sized_symbol<32>* gsym,
11004     unsigned int r_sym,
11005     const Symbol_value<32>* psymval,
11006     elfcpp::Elf_types<32>::Elf_Swxword addend,
11007     Arm_address address)
11008 {
11009   const Arm_relobj<big_endian>* arm_relobj =
11010     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11011
11012   bool target_is_thumb;
11013   Symbol_value<32> symval;
11014   if (gsym != NULL)
11015     {
11016       // This is a global symbol.  Determine if we use PLT and if the
11017       // final target is THUMB.
11018       if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
11019         {
11020           // This uses a PLT, change the symbol value.
11021           symval.set_output_value(this->plt_section()->address()
11022                                   + gsym->plt_offset());
11023           psymval = &symval;
11024           target_is_thumb = false;
11025         }
11026       else if (gsym->is_undefined())
11027         // There is no need to generate a stub symbol is undefined.
11028         return;
11029       else
11030         {
11031           target_is_thumb =
11032             ((gsym->type() == elfcpp::STT_ARM_TFUNC)
11033              || (gsym->type() == elfcpp::STT_FUNC
11034                  && !gsym->is_undefined()
11035                  && ((psymval->value(arm_relobj, 0) & 1) != 0)));
11036         }
11037     }
11038   else
11039     {
11040       // This is a local symbol.  Determine if the final target is THUMB.
11041       target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
11042     }
11043
11044   // Strip LSB if this points to a THUMB target.
11045   const Arm_reloc_property* reloc_property =
11046     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
11047   gold_assert(reloc_property != NULL);
11048   if (target_is_thumb
11049       && reloc_property->uses_thumb_bit()
11050       && ((psymval->value(arm_relobj, 0) & 1) != 0))
11051     {
11052       Arm_address stripped_value =
11053         psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
11054       symval.set_output_value(stripped_value);
11055       psymval = &symval;
11056     }
11057
11058   // Get the symbol value.
11059   Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
11060
11061   // Owing to pipelining, the PC relative branches below actually skip
11062   // two instructions when the branch offset is 0.
11063   Arm_address destination;
11064   switch (r_type)
11065     {
11066     case elfcpp::R_ARM_CALL:
11067     case elfcpp::R_ARM_JUMP24:
11068     case elfcpp::R_ARM_PLT32:
11069       // ARM branches.
11070       destination = value + addend + 8;
11071       break;
11072     case elfcpp::R_ARM_THM_CALL:
11073     case elfcpp::R_ARM_THM_XPC22:
11074     case elfcpp::R_ARM_THM_JUMP24:
11075     case elfcpp::R_ARM_THM_JUMP19:
11076       // THUMB branches.
11077       destination = value + addend + 4;
11078       break;
11079     default:
11080       gold_unreachable();
11081     }
11082
11083   Reloc_stub* stub = NULL;
11084   Stub_type stub_type =
11085     Reloc_stub::stub_type_for_reloc(r_type, address, destination,
11086                                     target_is_thumb);
11087   if (stub_type != arm_stub_none)
11088     {
11089       // Try looking up an existing stub from a stub table.
11090       Stub_table<big_endian>* stub_table =
11091         arm_relobj->stub_table(relinfo->data_shndx);
11092       gold_assert(stub_table != NULL);
11093
11094       // Locate stub by destination.
11095       Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
11096
11097       // Create a stub if there is not one already
11098       stub = stub_table->find_reloc_stub(stub_key);
11099       if (stub == NULL)
11100         {
11101           // create a new stub and add it to stub table.
11102           stub = this->stub_factory().make_reloc_stub(stub_type);
11103           stub_table->add_reloc_stub(stub, stub_key);
11104         }
11105
11106       // Record the destination address.
11107       stub->set_destination_address(destination
11108                                     | (target_is_thumb ? 1 : 0));
11109     }
11110
11111   // For Cortex-A8, we need to record a relocation at 4K page boundary.
11112   if (this->fix_cortex_a8_
11113       && (r_type == elfcpp::R_ARM_THM_JUMP24
11114           || r_type == elfcpp::R_ARM_THM_JUMP19
11115           || r_type == elfcpp::R_ARM_THM_CALL
11116           || r_type == elfcpp::R_ARM_THM_XPC22)
11117       && (address & 0xfffU) == 0xffeU)
11118     {
11119       // Found a candidate.  Note we haven't checked the destination is
11120       // within 4K here: if we do so (and don't create a record) we can't
11121       // tell that a branch should have been relocated when scanning later.
11122       this->cortex_a8_relocs_info_[address] =
11123         new Cortex_a8_reloc(stub, r_type,
11124                             destination | (target_is_thumb ? 1 : 0));
11125     }
11126 }
11127
11128 // This function scans a relocation sections for stub generation.
11129 // The template parameter Relocate must be a class type which provides
11130 // a single function, relocate(), which implements the machine
11131 // specific part of a relocation.
11132
11133 // BIG_ENDIAN is the endianness of the data.  SH_TYPE is the section type:
11134 // SHT_REL or SHT_RELA.
11135
11136 // PRELOCS points to the relocation data.  RELOC_COUNT is the number
11137 // of relocs.  OUTPUT_SECTION is the output section.
11138 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
11139 // mapped to output offsets.
11140
11141 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
11142 // VIEW_SIZE is the size.  These refer to the input section, unless
11143 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
11144 // the output section.
11145
11146 template<bool big_endian>
11147 template<int sh_type>
11148 void inline
11149 Target_arm<big_endian>::scan_reloc_section_for_stubs(
11150     const Relocate_info<32, big_endian>* relinfo,
11151     const unsigned char* prelocs,
11152     size_t reloc_count,
11153     Output_section* output_section,
11154     bool needs_special_offset_handling,
11155     const unsigned char* view,
11156     elfcpp::Elf_types<32>::Elf_Addr view_address,
11157     section_size_type)
11158 {
11159   typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
11160   const int reloc_size =
11161     Reloc_types<sh_type, 32, big_endian>::reloc_size;
11162
11163   Arm_relobj<big_endian>* arm_object =
11164     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11165   unsigned int local_count = arm_object->local_symbol_count();
11166
11167   gold::Default_comdat_behavior default_comdat_behavior;
11168   Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11169
11170   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11171     {
11172       Reltype reloc(prelocs);
11173
11174       typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11175       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11176       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11177
11178       r_type = this->get_real_reloc_type(r_type);
11179
11180       // Only a few relocation types need stubs.
11181       if ((r_type != elfcpp::R_ARM_CALL)
11182          && (r_type != elfcpp::R_ARM_JUMP24)
11183          && (r_type != elfcpp::R_ARM_PLT32)
11184          && (r_type != elfcpp::R_ARM_THM_CALL)
11185          && (r_type != elfcpp::R_ARM_THM_XPC22)
11186          && (r_type != elfcpp::R_ARM_THM_JUMP24)
11187          && (r_type != elfcpp::R_ARM_THM_JUMP19)
11188          && (r_type != elfcpp::R_ARM_V4BX))
11189         continue;
11190
11191       section_offset_type offset =
11192         convert_to_section_size_type(reloc.get_r_offset());
11193
11194       if (needs_special_offset_handling)
11195         {
11196           offset = output_section->output_offset(relinfo->object,
11197                                                  relinfo->data_shndx,
11198                                                  offset);
11199           if (offset == -1)
11200             continue;
11201         }
11202
11203       // Create a v4bx stub if --fix-v4bx-interworking is used.
11204       if (r_type == elfcpp::R_ARM_V4BX)
11205         {
11206           if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11207             {
11208               // Get the BX instruction.
11209               typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11210               const Valtype* wv =
11211                 reinterpret_cast<const Valtype*>(view + offset);
11212               elfcpp::Elf_types<32>::Elf_Swxword insn =
11213                 elfcpp::Swap<32, big_endian>::readval(wv);
11214               const uint32_t reg = (insn & 0xf);
11215
11216               if (reg < 0xf)
11217                 {
11218                   // Try looking up an existing stub from a stub table.
11219                   Stub_table<big_endian>* stub_table =
11220                     arm_object->stub_table(relinfo->data_shndx);
11221                   gold_assert(stub_table != NULL);
11222
11223                   if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11224                     {
11225                       // create a new stub and add it to stub table.
11226                       Arm_v4bx_stub* stub =
11227                         this->stub_factory().make_arm_v4bx_stub(reg);
11228                       gold_assert(stub != NULL);
11229                       stub_table->add_arm_v4bx_stub(stub);
11230                     }
11231                 }
11232             }
11233           continue;
11234         }
11235
11236       // Get the addend.
11237       Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11238       elfcpp::Elf_types<32>::Elf_Swxword addend =
11239         stub_addend_reader(r_type, view + offset, reloc);
11240
11241       const Sized_symbol<32>* sym;
11242
11243       Symbol_value<32> symval;
11244       const Symbol_value<32> *psymval;
11245       bool is_defined_in_discarded_section;
11246       unsigned int shndx;
11247       if (r_sym < local_count)
11248         {
11249           sym = NULL;
11250           psymval = arm_object->local_symbol(r_sym);
11251
11252           // If the local symbol belongs to a section we are discarding,
11253           // and that section is a debug section, try to find the
11254           // corresponding kept section and map this symbol to its
11255           // counterpart in the kept section.  The symbol must not
11256           // correspond to a section we are folding.
11257           bool is_ordinary;
11258           shndx = psymval->input_shndx(&is_ordinary);
11259           is_defined_in_discarded_section =
11260             (is_ordinary
11261              && shndx != elfcpp::SHN_UNDEF
11262              && !arm_object->is_section_included(shndx)
11263              && !relinfo->symtab->is_section_folded(arm_object, shndx));
11264
11265           // We need to compute the would-be final value of this local
11266           // symbol.
11267           if (!is_defined_in_discarded_section)
11268             {
11269               typedef Sized_relobj_file<32, big_endian> ObjType;
11270               typename ObjType::Compute_final_local_value_status status =
11271                 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11272                                                       relinfo->symtab);
11273               if (status == ObjType::CFLV_OK)
11274                 {
11275                   // Currently we cannot handle a branch to a target in
11276                   // a merged section.  If this is the case, issue an error
11277                   // and also free the merge symbol value.
11278                   if (!symval.has_output_value())
11279                     {
11280                       const std::string& section_name =
11281                         arm_object->section_name(shndx);
11282                       arm_object->error(_("cannot handle branch to local %u "
11283                                           "in a merged section %s"),
11284                                         r_sym, section_name.c_str());
11285                     }
11286                   psymval = &symval;
11287                 }
11288               else
11289                 {
11290                   // We cannot determine the final value.
11291                   continue;
11292                 }
11293             }
11294         }
11295       else
11296         {
11297           const Symbol* gsym;
11298           gsym = arm_object->global_symbol(r_sym);
11299           gold_assert(gsym != NULL);
11300           if (gsym->is_forwarder())
11301             gsym = relinfo->symtab->resolve_forwards(gsym);
11302
11303           sym = static_cast<const Sized_symbol<32>*>(gsym);
11304           if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11305             symval.set_output_symtab_index(sym->symtab_index());
11306           else
11307             symval.set_no_output_symtab_entry();
11308
11309           // We need to compute the would-be final value of this global
11310           // symbol.
11311           const Symbol_table* symtab = relinfo->symtab;
11312           const Sized_symbol<32>* sized_symbol =
11313             symtab->get_sized_symbol<32>(gsym);
11314           Symbol_table::Compute_final_value_status status;
11315           Arm_address value =
11316             symtab->compute_final_value<32>(sized_symbol, &status);
11317
11318           // Skip this if the symbol has not output section.
11319           if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11320             continue;
11321           symval.set_output_value(value);
11322
11323           if (gsym->type() == elfcpp::STT_TLS)
11324             symval.set_is_tls_symbol();
11325           else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11326             symval.set_is_ifunc_symbol();
11327           psymval = &symval;
11328
11329           is_defined_in_discarded_section =
11330             (gsym->is_defined_in_discarded_section()
11331              && gsym->is_undefined());
11332           shndx = 0;
11333         }
11334
11335       Symbol_value<32> symval2;
11336       if (is_defined_in_discarded_section)
11337         {
11338           if (comdat_behavior == CB_UNDETERMINED)
11339             {
11340               std::string name = arm_object->section_name(relinfo->data_shndx);
11341               comdat_behavior = default_comdat_behavior.get(name.c_str());
11342             }
11343           if (comdat_behavior == CB_PRETEND)
11344             {
11345               // FIXME: This case does not work for global symbols.
11346               // We have no place to store the original section index.
11347               // Fortunately this does not matter for comdat sections,
11348               // only for sections explicitly discarded by a linker
11349               // script.
11350               bool found;
11351               typename elfcpp::Elf_types<32>::Elf_Addr value =
11352                 arm_object->map_to_kept_section(shndx, &found);
11353               if (found)
11354                 symval2.set_output_value(value + psymval->input_value());
11355               else
11356                 symval2.set_output_value(0);
11357             }
11358           else
11359             {
11360               if (comdat_behavior == CB_WARNING)
11361                 gold_warning_at_location(relinfo, i, offset,
11362                                          _("relocation refers to discarded "
11363                                            "section"));
11364               symval2.set_output_value(0);
11365             }
11366           symval2.set_no_output_symtab_entry();
11367           psymval = &symval2;
11368         }
11369
11370       // If symbol is a section symbol, we don't know the actual type of
11371       // destination.  Give up.
11372       if (psymval->is_section_symbol())
11373         continue;
11374
11375       this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11376                                 addend, view_address + offset);
11377     }
11378 }
11379
11380 // Scan an input section for stub generation.
11381
11382 template<bool big_endian>
11383 void
11384 Target_arm<big_endian>::scan_section_for_stubs(
11385     const Relocate_info<32, big_endian>* relinfo,
11386     unsigned int sh_type,
11387     const unsigned char* prelocs,
11388     size_t reloc_count,
11389     Output_section* output_section,
11390     bool needs_special_offset_handling,
11391     const unsigned char* view,
11392     Arm_address view_address,
11393     section_size_type view_size)
11394 {
11395   if (sh_type == elfcpp::SHT_REL)
11396     this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11397         relinfo,
11398         prelocs,
11399         reloc_count,
11400         output_section,
11401         needs_special_offset_handling,
11402         view,
11403         view_address,
11404         view_size);
11405   else if (sh_type == elfcpp::SHT_RELA)
11406     // We do not support RELA type relocations yet.  This is provided for
11407     // completeness.
11408     this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11409         relinfo,
11410         prelocs,
11411         reloc_count,
11412         output_section,
11413         needs_special_offset_handling,
11414         view,
11415         view_address,
11416         view_size);
11417   else
11418     gold_unreachable();
11419 }
11420
11421 // Group input sections for stub generation.
11422 //
11423 // We group input sections in an output section so that the total size,
11424 // including any padding space due to alignment is smaller than GROUP_SIZE
11425 // unless the only input section in group is bigger than GROUP_SIZE already.
11426 // Then an ARM stub table is created to follow the last input section
11427 // in group.  For each group an ARM stub table is created an is placed
11428 // after the last group.  If STUB_ALWAYS_AFTER_BRANCH is false, we further
11429 // extend the group after the stub table.
11430
11431 template<bool big_endian>
11432 void
11433 Target_arm<big_endian>::group_sections(
11434     Layout* layout,
11435     section_size_type group_size,
11436     bool stubs_always_after_branch,
11437     const Task* task)
11438 {
11439   // Group input sections and insert stub table
11440   Layout::Section_list section_list;
11441   layout->get_executable_sections(&section_list);
11442   for (Layout::Section_list::const_iterator p = section_list.begin();
11443        p != section_list.end();
11444        ++p)
11445     {
11446       Arm_output_section<big_endian>* output_section =
11447         Arm_output_section<big_endian>::as_arm_output_section(*p);
11448       output_section->group_sections(group_size, stubs_always_after_branch,
11449                                      this, task);
11450     }
11451 }
11452
11453 // Relaxation hook.  This is where we do stub generation.
11454
11455 template<bool big_endian>
11456 bool
11457 Target_arm<big_endian>::do_relax(
11458     int pass,
11459     const Input_objects* input_objects,
11460     Symbol_table* symtab,
11461     Layout* layout,
11462     const Task* task)
11463 {
11464   // No need to generate stubs if this is a relocatable link.
11465   gold_assert(!parameters->options().relocatable());
11466
11467   // If this is the first pass, we need to group input sections into
11468   // stub groups.
11469   bool done_exidx_fixup = false;
11470   typedef typename Stub_table_list::iterator Stub_table_iterator;
11471   if (pass == 1)
11472     {
11473       // Determine the stub group size.  The group size is the absolute
11474       // value of the parameter --stub-group-size.  If --stub-group-size
11475       // is passed a negative value, we restrict stubs to be always after
11476       // the stubbed branches.
11477       int32_t stub_group_size_param =
11478         parameters->options().stub_group_size();
11479       bool stubs_always_after_branch = stub_group_size_param < 0;
11480       section_size_type stub_group_size = abs(stub_group_size_param);
11481
11482       if (stub_group_size == 1)
11483         {
11484           // Default value.
11485           // Thumb branch range is +-4MB has to be used as the default
11486           // maximum size (a given section can contain both ARM and Thumb
11487           // code, so the worst case has to be taken into account).  If we are
11488           // fixing cortex-a8 errata, the branch range has to be even smaller,
11489           // since wide conditional branch has a range of +-1MB only.
11490           //
11491           // This value is 48K less than that, which allows for 4096
11492           // 12-byte stubs.  If we exceed that, then we will fail to link.
11493           // The user will have to relink with an explicit group size
11494           // option.
11495             stub_group_size = 4145152;
11496         }
11497
11498       // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11499       // page as the first half of a 32-bit branch straddling two 4K pages.
11500       // This is a crude way of enforcing that.  In addition, long conditional
11501       // branches of THUMB-2 have a range of +-1M.  If we are fixing cortex-A8
11502       // erratum, limit the group size to  (1M - 12k) to avoid unreachable
11503       // cortex-A8 stubs from long conditional branches.
11504       if (this->fix_cortex_a8_)
11505         {
11506           stubs_always_after_branch = true;
11507           const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11508           stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11509         }
11510
11511       group_sections(layout, stub_group_size, stubs_always_after_branch, task);
11512
11513       // Also fix .ARM.exidx section coverage.
11514       Arm_output_section<big_endian>* exidx_output_section = NULL;
11515       for (Layout::Section_list::const_iterator p =
11516              layout->section_list().begin();
11517            p != layout->section_list().end();
11518            ++p)
11519         if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11520           {
11521             if (exidx_output_section == NULL)
11522               exidx_output_section =
11523                 Arm_output_section<big_endian>::as_arm_output_section(*p);
11524             else
11525               // We cannot handle this now.
11526               gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11527                            "non-relocatable link"),
11528                           exidx_output_section->name(),
11529                           (*p)->name());
11530           }
11531
11532       if (exidx_output_section != NULL)
11533         {
11534           this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11535                                    symtab, task);
11536           done_exidx_fixup = true;
11537         }
11538     }
11539   else
11540     {
11541       // If this is not the first pass, addresses and file offsets have
11542       // been reset at this point, set them here.
11543       for (Stub_table_iterator sp = this->stub_tables_.begin();
11544            sp != this->stub_tables_.end();
11545            ++sp)
11546         {
11547           Arm_input_section<big_endian>* owner = (*sp)->owner();
11548           off_t off = align_address(owner->original_size(),
11549                                     (*sp)->addralign());
11550           (*sp)->set_address_and_file_offset(owner->address() + off,
11551                                              owner->offset() + off);
11552         }
11553     }
11554
11555   // The Cortex-A8 stubs are sensitive to layout of code sections.  At the
11556   // beginning of each relaxation pass, just blow away all the stubs.
11557   // Alternatively, we could selectively remove only the stubs and reloc
11558   // information for code sections that have moved since the last pass.
11559   // That would require more book-keeping.
11560   if (this->fix_cortex_a8_)
11561     {
11562       // Clear all Cortex-A8 reloc information.
11563       for (typename Cortex_a8_relocs_info::const_iterator p =
11564              this->cortex_a8_relocs_info_.begin();
11565            p != this->cortex_a8_relocs_info_.end();
11566            ++p)
11567         delete p->second;
11568       this->cortex_a8_relocs_info_.clear();
11569
11570       // Remove all Cortex-A8 stubs.
11571       for (Stub_table_iterator sp = this->stub_tables_.begin();
11572            sp != this->stub_tables_.end();
11573            ++sp)
11574         (*sp)->remove_all_cortex_a8_stubs();
11575     }
11576
11577   // Scan relocs for relocation stubs
11578   for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11579        op != input_objects->relobj_end();
11580        ++op)
11581     {
11582       Arm_relobj<big_endian>* arm_relobj =
11583         Arm_relobj<big_endian>::as_arm_relobj(*op);
11584       // Lock the object so we can read from it.  This is only called
11585       // single-threaded from Layout::finalize, so it is OK to lock.
11586       Task_lock_obj<Object> tl(task, arm_relobj);
11587       arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11588     }
11589
11590   // Check all stub tables to see if any of them have their data sizes
11591   // or addresses alignments changed.  These are the only things that
11592   // matter.
11593   bool any_stub_table_changed = false;
11594   Unordered_set<const Output_section*> sections_needing_adjustment;
11595   for (Stub_table_iterator sp = this->stub_tables_.begin();
11596        (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11597        ++sp)
11598     {
11599       if ((*sp)->update_data_size_and_addralign())
11600         {
11601           // Update data size of stub table owner.
11602           Arm_input_section<big_endian>* owner = (*sp)->owner();
11603           uint64_t address = owner->address();
11604           off_t offset = owner->offset();
11605           owner->reset_address_and_file_offset();
11606           owner->set_address_and_file_offset(address, offset);
11607
11608           sections_needing_adjustment.insert(owner->output_section());
11609           any_stub_table_changed = true;
11610         }
11611     }
11612
11613   // Output_section_data::output_section() returns a const pointer but we
11614   // need to update output sections, so we record all output sections needing
11615   // update above and scan the sections here to find out what sections need
11616   // to be updated.
11617   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
11618       p != layout->section_list().end();
11619       ++p)
11620     {
11621       if (sections_needing_adjustment.find(*p)
11622           != sections_needing_adjustment.end())
11623         (*p)->set_section_offsets_need_adjustment();
11624     }
11625
11626   // Stop relaxation if no EXIDX fix-up and no stub table change.
11627   bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11628
11629   // Finalize the stubs in the last relaxation pass.
11630   if (!continue_relaxation)
11631     {
11632       for (Stub_table_iterator sp = this->stub_tables_.begin();
11633            (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11634             ++sp)
11635         (*sp)->finalize_stubs();
11636
11637       // Update output local symbol counts of objects if necessary.
11638       for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11639            op != input_objects->relobj_end();
11640            ++op)
11641         {
11642           Arm_relobj<big_endian>* arm_relobj =
11643             Arm_relobj<big_endian>::as_arm_relobj(*op);
11644
11645           // Update output local symbol counts.  We need to discard local
11646           // symbols defined in parts of input sections that are discarded by
11647           // relaxation.
11648           if (arm_relobj->output_local_symbol_count_needs_update())
11649             {
11650               // We need to lock the object's file to update it.
11651               Task_lock_obj<Object> tl(task, arm_relobj);
11652               arm_relobj->update_output_local_symbol_count();
11653             }
11654         }
11655     }
11656
11657   return continue_relaxation;
11658 }
11659
11660 // Relocate a stub.
11661
11662 template<bool big_endian>
11663 void
11664 Target_arm<big_endian>::relocate_stub(
11665     Stub* stub,
11666     const Relocate_info<32, big_endian>* relinfo,
11667     Output_section* output_section,
11668     unsigned char* view,
11669     Arm_address address,
11670     section_size_type view_size)
11671 {
11672   Relocate relocate;
11673   const Stub_template* stub_template = stub->stub_template();
11674   for (size_t i = 0; i < stub_template->reloc_count(); i++)
11675     {
11676       size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11677       const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11678
11679       unsigned int r_type = insn->r_type();
11680       section_size_type reloc_offset = stub_template->reloc_offset(i);
11681       section_size_type reloc_size = insn->size();
11682       gold_assert(reloc_offset + reloc_size <= view_size);
11683
11684       // This is the address of the stub destination.
11685       Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11686       Symbol_value<32> symval;
11687       symval.set_output_value(target);
11688
11689       // Synthesize a fake reloc just in case.  We don't have a symbol so
11690       // we use 0.
11691       unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11692       memset(reloc_buffer, 0, sizeof(reloc_buffer));
11693       elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11694       reloc_write.put_r_offset(reloc_offset);
11695       reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11696       elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11697
11698       relocate.relocate(relinfo, this, output_section,
11699                         this->fake_relnum_for_stubs, rel, r_type,
11700                         NULL, &symval, view + reloc_offset,
11701                         address + reloc_offset, reloc_size);
11702     }
11703 }
11704
11705 // Determine whether an object attribute tag takes an integer, a
11706 // string or both.
11707
11708 template<bool big_endian>
11709 int
11710 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11711 {
11712   if (tag == Object_attribute::Tag_compatibility)
11713     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11714             | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11715   else if (tag == elfcpp::Tag_nodefaults)
11716     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11717             | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11718   else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11719     return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11720   else if (tag < 32)
11721     return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11722   else
11723     return ((tag & 1) != 0
11724             ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11725             : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11726 }
11727
11728 // Reorder attributes.
11729 //
11730 // The ABI defines that Tag_conformance should be emitted first, and that
11731 // Tag_nodefaults should be second (if either is defined).  This sets those
11732 // two positions, and bumps up the position of all the remaining tags to
11733 // compensate.
11734
11735 template<bool big_endian>
11736 int
11737 Target_arm<big_endian>::do_attributes_order(int num) const
11738 {
11739   // Reorder the known object attributes in output.  We want to move
11740   // Tag_conformance to position 4 and Tag_conformance to position 5
11741   // and shift everything between 4 .. Tag_conformance - 1 to make room.
11742   if (num == 4)
11743     return elfcpp::Tag_conformance;
11744   if (num == 5)
11745     return elfcpp::Tag_nodefaults;
11746   if ((num - 2) < elfcpp::Tag_nodefaults)
11747     return num - 2;
11748   if ((num - 1) < elfcpp::Tag_conformance)
11749     return num - 1;
11750   return num;
11751 }
11752
11753 // Scan a span of THUMB code for Cortex-A8 erratum.
11754
11755 template<bool big_endian>
11756 void
11757 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11758     Arm_relobj<big_endian>* arm_relobj,
11759     unsigned int shndx,
11760     section_size_type span_start,
11761     section_size_type span_end,
11762     const unsigned char* view,
11763     Arm_address address)
11764 {
11765   // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11766   //
11767   // The opcode is BLX.W, BL.W, B.W, Bcc.W
11768   // The branch target is in the same 4KB region as the
11769   // first half of the branch.
11770   // The instruction before the branch is a 32-bit
11771   // length non-branch instruction.
11772   section_size_type i = span_start;
11773   bool last_was_32bit = false;
11774   bool last_was_branch = false;
11775   while (i < span_end)
11776     {
11777       typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11778       const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11779       uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11780       bool is_blx = false, is_b = false;
11781       bool is_bl = false, is_bcc = false;
11782
11783       bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11784       if (insn_32bit)
11785         {
11786           // Load the rest of the insn (in manual-friendly order).
11787           insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11788
11789           // Encoding T4: B<c>.W.
11790           is_b = (insn & 0xf800d000U) == 0xf0009000U;
11791           // Encoding T1: BL<c>.W.
11792           is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11793           // Encoding T2: BLX<c>.W.
11794           is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11795           // Encoding T3: B<c>.W (not permitted in IT block).
11796           is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11797                     && (insn & 0x07f00000U) != 0x03800000U);
11798         }
11799
11800       bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11801
11802       // If this instruction is a 32-bit THUMB branch that crosses a 4K
11803       // page boundary and it follows 32-bit non-branch instruction,
11804       // we need to work around.
11805       if (is_32bit_branch
11806           && ((address + i) & 0xfffU) == 0xffeU
11807           && last_was_32bit
11808           && !last_was_branch)
11809         {
11810           // Check to see if there is a relocation stub for this branch.
11811           bool force_target_arm = false;
11812           bool force_target_thumb = false;
11813           const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11814           Cortex_a8_relocs_info::const_iterator p =
11815             this->cortex_a8_relocs_info_.find(address + i);
11816
11817           if (p != this->cortex_a8_relocs_info_.end())
11818             {
11819               cortex_a8_reloc = p->second;
11820               bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11821
11822               if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11823                   && !target_is_thumb)
11824                 force_target_arm = true;
11825               else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11826                        && target_is_thumb)
11827                 force_target_thumb = true;
11828             }
11829
11830           off_t offset;
11831           Stub_type stub_type = arm_stub_none;
11832
11833           // Check if we have an offending branch instruction.
11834           uint16_t upper_insn = (insn >> 16) & 0xffffU;
11835           uint16_t lower_insn = insn & 0xffffU;
11836           typedef class Arm_relocate_functions<big_endian> RelocFuncs;
11837
11838           if (cortex_a8_reloc != NULL
11839               && cortex_a8_reloc->reloc_stub() != NULL)
11840             // We've already made a stub for this instruction, e.g.
11841             // it's a long branch or a Thumb->ARM stub.  Assume that
11842             // stub will suffice to work around the A8 erratum (see
11843             // setting of always_after_branch above).
11844             ;
11845           else if (is_bcc)
11846             {
11847               offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11848                                                               lower_insn);
11849               stub_type = arm_stub_a8_veneer_b_cond;
11850             }
11851           else if (is_b || is_bl || is_blx)
11852             {
11853               offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11854                                                          lower_insn);
11855               if (is_blx)
11856                 offset &= ~3;
11857
11858               stub_type = (is_blx
11859                            ? arm_stub_a8_veneer_blx
11860                            : (is_bl
11861                               ? arm_stub_a8_veneer_bl
11862                               : arm_stub_a8_veneer_b));
11863             }
11864
11865           if (stub_type != arm_stub_none)
11866             {
11867               Arm_address pc_for_insn = address + i + 4;
11868
11869               // The original instruction is a BL, but the target is
11870               // an ARM instruction.  If we were not making a stub,
11871               // the BL would have been converted to a BLX.  Use the
11872               // BLX stub instead in that case.
11873               if (this->may_use_v5t_interworking() && force_target_arm
11874                   && stub_type == arm_stub_a8_veneer_bl)
11875                 {
11876                   stub_type = arm_stub_a8_veneer_blx;
11877                   is_blx = true;
11878                   is_bl = false;
11879                 }
11880               // Conversely, if the original instruction was
11881               // BLX but the target is Thumb mode, use the BL stub.
11882               else if (force_target_thumb
11883                        && stub_type == arm_stub_a8_veneer_blx)
11884                 {
11885                   stub_type = arm_stub_a8_veneer_bl;
11886                   is_blx = false;
11887                   is_bl = true;
11888                 }
11889
11890               if (is_blx)
11891                 pc_for_insn &= ~3;
11892
11893               // If we found a relocation, use the proper destination,
11894               // not the offset in the (unrelocated) instruction.
11895               // Note this is always done if we switched the stub type above.
11896               if (cortex_a8_reloc != NULL)
11897                 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11898
11899               Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11900
11901               // Add a new stub if destination address in in the same page.
11902               if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11903                 {
11904                   Cortex_a8_stub* stub =
11905                     this->stub_factory_.make_cortex_a8_stub(stub_type,
11906                                                             arm_relobj, shndx,
11907                                                             address + i,
11908                                                             target, insn);
11909                   Stub_table<big_endian>* stub_table =
11910                     arm_relobj->stub_table(shndx);
11911                   gold_assert(stub_table != NULL);
11912                   stub_table->add_cortex_a8_stub(address + i, stub);
11913                 }
11914             }
11915         }
11916
11917       i += insn_32bit ? 4 : 2;
11918       last_was_32bit = insn_32bit;
11919       last_was_branch = is_32bit_branch;
11920     }
11921 }
11922
11923 // Apply the Cortex-A8 workaround.
11924
11925 template<bool big_endian>
11926 void
11927 Target_arm<big_endian>::apply_cortex_a8_workaround(
11928     const Cortex_a8_stub* stub,
11929     Arm_address stub_address,
11930     unsigned char* insn_view,
11931     Arm_address insn_address)
11932 {
11933   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11934   Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
11935   Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
11936   Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
11937   off_t branch_offset = stub_address - (insn_address + 4);
11938
11939   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
11940   switch (stub->stub_template()->type())
11941     {
11942     case arm_stub_a8_veneer_b_cond:
11943       // For a conditional branch, we re-write it to be an unconditional
11944       // branch to the stub.  We use the THUMB-2 encoding here.
11945       upper_insn = 0xf000U;
11946       lower_insn = 0xb800U;
11947       // Fall through
11948     case arm_stub_a8_veneer_b:
11949     case arm_stub_a8_veneer_bl:
11950     case arm_stub_a8_veneer_blx:
11951       if ((lower_insn & 0x5000U) == 0x4000U)
11952         // For a BLX instruction, make sure that the relocation is
11953         // rounded up to a word boundary.  This follows the semantics of
11954         // the instruction which specifies that bit 1 of the target
11955         // address will come from bit 1 of the base address.
11956         branch_offset = (branch_offset + 2) & ~3;
11957
11958       // Put BRANCH_OFFSET back into the insn.
11959       gold_assert(!Bits<25>::has_overflow32(branch_offset));
11960       upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
11961       lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
11962       break;
11963
11964     default:
11965       gold_unreachable();
11966     }
11967
11968   // Put the relocated value back in the object file:
11969   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
11970   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
11971 }
11972
11973 // Target selector for ARM.  Note this is never instantiated directly.
11974 // It's only used in Target_selector_arm_nacl, below.
11975
11976 template<bool big_endian>
11977 class Target_selector_arm : public Target_selector
11978 {
11979  public:
11980   Target_selector_arm()
11981     : Target_selector(elfcpp::EM_ARM, 32, big_endian,
11982                       (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
11983                       (big_endian ? "armelfb" : "armelf"))
11984   { }
11985
11986   Target*
11987   do_instantiate_target()
11988   { return new Target_arm<big_endian>(); }
11989 };
11990
11991 // Fix .ARM.exidx section coverage.
11992
11993 template<bool big_endian>
11994 void
11995 Target_arm<big_endian>::fix_exidx_coverage(
11996     Layout* layout,
11997     const Input_objects* input_objects,
11998     Arm_output_section<big_endian>* exidx_section,
11999     Symbol_table* symtab,
12000     const Task* task)
12001 {
12002   // We need to look at all the input sections in output in ascending
12003   // order of of output address.  We do that by building a sorted list
12004   // of output sections by addresses.  Then we looks at the output sections
12005   // in order.  The input sections in an output section are already sorted
12006   // by addresses within the output section.
12007
12008   typedef std::set<Output_section*, output_section_address_less_than>
12009       Sorted_output_section_list;
12010   Sorted_output_section_list sorted_output_sections;
12011
12012   // Find out all the output sections of input sections pointed by
12013   // EXIDX input sections.
12014   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
12015        p != input_objects->relobj_end();
12016        ++p)
12017     {
12018       Arm_relobj<big_endian>* arm_relobj =
12019         Arm_relobj<big_endian>::as_arm_relobj(*p);
12020       std::vector<unsigned int> shndx_list;
12021       arm_relobj->get_exidx_shndx_list(&shndx_list);
12022       for (size_t i = 0; i < shndx_list.size(); ++i)
12023         {
12024           const Arm_exidx_input_section* exidx_input_section =
12025             arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
12026           gold_assert(exidx_input_section != NULL);
12027           if (!exidx_input_section->has_errors())
12028             {
12029               unsigned int text_shndx = exidx_input_section->link();
12030               Output_section* os = arm_relobj->output_section(text_shndx);
12031               if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
12032                 sorted_output_sections.insert(os);
12033             }
12034         }
12035     }
12036
12037   // Go over the output sections in ascending order of output addresses.
12038   typedef typename Arm_output_section<big_endian>::Text_section_list
12039       Text_section_list;
12040   Text_section_list sorted_text_sections;
12041   for (typename Sorted_output_section_list::iterator p =
12042         sorted_output_sections.begin();
12043       p != sorted_output_sections.end();
12044       ++p)
12045     {
12046       Arm_output_section<big_endian>* arm_output_section =
12047         Arm_output_section<big_endian>::as_arm_output_section(*p);
12048       arm_output_section->append_text_sections_to_list(&sorted_text_sections);
12049     }
12050
12051   exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
12052                                     merge_exidx_entries(), task);
12053 }
12054
12055 template<bool big_endian>
12056 void
12057 Target_arm<big_endian>::do_define_standard_symbols(
12058     Symbol_table* symtab,
12059     Layout* layout)
12060 {
12061   // Handle the .ARM.exidx section.
12062   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
12063
12064   if (exidx_section != NULL)
12065     {
12066       // Create __exidx_start and __exidx_end symbols.
12067       symtab->define_in_output_data("__exidx_start",
12068                                     NULL, // version
12069                                     Symbol_table::PREDEFINED,
12070                                     exidx_section,
12071                                     0, // value
12072                                     0, // symsize
12073                                     elfcpp::STT_NOTYPE,
12074                                     elfcpp::STB_GLOBAL,
12075                                     elfcpp::STV_HIDDEN,
12076                                     0, // nonvis
12077                                     false, // offset_is_from_end
12078                                     true); // only_if_ref
12079
12080       symtab->define_in_output_data("__exidx_end",
12081                                     NULL, // version
12082                                     Symbol_table::PREDEFINED,
12083                                     exidx_section,
12084                                     0, // value
12085                                     0, // symsize
12086                                     elfcpp::STT_NOTYPE,
12087                                     elfcpp::STB_GLOBAL,
12088                                     elfcpp::STV_HIDDEN,
12089                                     0, // nonvis
12090                                     true, // offset_is_from_end
12091                                     true); // only_if_ref
12092     }
12093   else
12094     {
12095       // Define __exidx_start and __exidx_end even when .ARM.exidx
12096       // section is missing to match ld's behaviour.
12097       symtab->define_as_constant("__exidx_start", NULL,
12098                                  Symbol_table::PREDEFINED,
12099                                  0, 0, elfcpp::STT_OBJECT,
12100                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12101                                  true, false);
12102       symtab->define_as_constant("__exidx_end", NULL,
12103                                  Symbol_table::PREDEFINED,
12104                                  0, 0, elfcpp::STT_OBJECT,
12105                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12106                                  true, false);
12107     }
12108 }
12109
12110 // NaCl variant.  It uses different PLT contents.
12111
12112 template<bool big_endian>
12113 class Output_data_plt_arm_nacl;
12114
12115 template<bool big_endian>
12116 class Target_arm_nacl : public Target_arm<big_endian>
12117 {
12118  public:
12119   Target_arm_nacl()
12120     : Target_arm<big_endian>(&arm_nacl_info)
12121   { }
12122
12123  protected:
12124   virtual Output_data_plt_arm<big_endian>*
12125   do_make_data_plt(Layout* layout, Output_data_space* got_plt)
12126   { return new Output_data_plt_arm_nacl<big_endian>(layout, got_plt); }
12127
12128  private:
12129   static const Target::Target_info arm_nacl_info;
12130 };
12131
12132 template<bool big_endian>
12133 const Target::Target_info Target_arm_nacl<big_endian>::arm_nacl_info =
12134 {
12135   32,                   // size
12136   big_endian,           // is_big_endian
12137   elfcpp::EM_ARM,       // machine_code
12138   false,                // has_make_symbol
12139   false,                // has_resolve
12140   false,                // has_code_fill
12141   true,                 // is_default_stack_executable
12142   false,                // can_icf_inline_merge_sections
12143   '\0',                 // wrap_char
12144   "/lib/ld-nacl-arm.so.1", // dynamic_linker
12145   0x20000,              // default_text_segment_address
12146   0x10000,              // abi_pagesize (overridable by -z max-page-size)
12147   0x10000,              // common_pagesize (overridable by -z common-page-size)
12148   true,                 // isolate_execinstr
12149   0x10000000,           // rosegment_gap
12150   elfcpp::SHN_UNDEF,    // small_common_shndx
12151   elfcpp::SHN_UNDEF,    // large_common_shndx
12152   0,                    // small_common_section_flags
12153   0,                    // large_common_section_flags
12154   ".ARM.attributes",    // attributes_section
12155   "aeabi"               // attributes_vendor
12156 };
12157
12158 template<bool big_endian>
12159 class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
12160 {
12161  public:
12162   Output_data_plt_arm_nacl(Layout* layout, Output_data_space* got_plt)
12163     : Output_data_plt_arm<big_endian>(layout, 16, got_plt)
12164   { }
12165
12166  protected:
12167   // Return the offset of the first non-reserved PLT entry.
12168   virtual unsigned int
12169   do_first_plt_entry_offset() const
12170   { return sizeof(first_plt_entry); }
12171
12172   // Return the size of a PLT entry.
12173   virtual unsigned int
12174   do_get_plt_entry_size() const
12175   { return sizeof(plt_entry); }
12176
12177   virtual void
12178   do_fill_first_plt_entry(unsigned char* pov,
12179                           Arm_address got_address,
12180                           Arm_address plt_address);
12181
12182   virtual void
12183   do_fill_plt_entry(unsigned char* pov,
12184                     Arm_address got_address,
12185                     Arm_address plt_address,
12186                     unsigned int got_offset,
12187                     unsigned int plt_offset);
12188
12189  private:
12190   inline uint32_t arm_movw_immediate(uint32_t value)
12191   {
12192     return (value & 0x00000fff) | ((value & 0x0000f000) << 4);
12193   }
12194
12195   inline uint32_t arm_movt_immediate(uint32_t value)
12196   {
12197     return ((value & 0x0fff0000) >> 16) | ((value & 0xf0000000) >> 12);
12198   }
12199
12200   // Template for the first PLT entry.
12201   static const uint32_t first_plt_entry[16];
12202
12203   // Template for subsequent PLT entries.
12204   static const uint32_t plt_entry[4];
12205 };
12206
12207 // The first entry in the PLT.
12208 template<bool big_endian>
12209 const uint32_t Output_data_plt_arm_nacl<big_endian>::first_plt_entry[16] =
12210 {
12211   // First bundle:
12212   0xe300c000,                           // movw ip, #:lower16:&GOT[2]-.+8
12213   0xe340c000,                           // movt ip, #:upper16:&GOT[2]-.+8
12214   0xe08cc00f,                           // add  ip, ip, pc
12215   0xe52dc008,                           // str  ip, [sp, #-8]!
12216   // Second bundle:
12217   0xe3ccc103,                           // bic  ip, ip, #0xc0000000
12218   0xe59cc000,                           // ldr  ip, [ip]
12219   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
12220   0xe12fff1c,                           // bx   ip
12221   // Third bundle:
12222   0xe320f000,                           // nop
12223   0xe320f000,                           // nop
12224   0xe320f000,                           // nop
12225   // .Lplt_tail:
12226   0xe50dc004,                           // str  ip, [sp, #-4]
12227   // Fourth bundle:
12228   0xe3ccc103,                           // bic  ip, ip, #0xc0000000
12229   0xe59cc000,                           // ldr  ip, [ip]
12230   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
12231   0xe12fff1c,                           // bx   ip
12232 };
12233
12234 template<bool big_endian>
12235 void
12236 Output_data_plt_arm_nacl<big_endian>::do_fill_first_plt_entry(
12237     unsigned char* pov,
12238     Arm_address got_address,
12239     Arm_address plt_address)
12240 {
12241   // Write first PLT entry.  All but first two words are constants.
12242   const size_t num_first_plt_words = (sizeof(first_plt_entry)
12243                                       / sizeof(first_plt_entry[0]));
12244
12245   int32_t got_displacement = got_address + 8 - (plt_address + 16);
12246
12247   elfcpp::Swap<32, big_endian>::writeval
12248     (pov + 0, first_plt_entry[0] | arm_movw_immediate (got_displacement));
12249   elfcpp::Swap<32, big_endian>::writeval
12250     (pov + 4, first_plt_entry[1] | arm_movt_immediate (got_displacement));
12251
12252   for (size_t i = 2; i < num_first_plt_words; ++i)
12253     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
12254 }
12255
12256 // Subsequent entries in the PLT.
12257
12258 template<bool big_endian>
12259 const uint32_t Output_data_plt_arm_nacl<big_endian>::plt_entry[4] =
12260 {
12261   0xe300c000,                           // movw ip, #:lower16:&GOT[n]-.+8
12262   0xe340c000,                           // movt ip, #:upper16:&GOT[n]-.+8
12263   0xe08cc00f,                           // add  ip, ip, pc
12264   0xea000000,                           // b    .Lplt_tail
12265 };
12266
12267 template<bool big_endian>
12268 void
12269 Output_data_plt_arm_nacl<big_endian>::do_fill_plt_entry(
12270     unsigned char* pov,
12271     Arm_address got_address,
12272     Arm_address plt_address,
12273     unsigned int got_offset,
12274     unsigned int plt_offset)
12275 {
12276   // Calculate the displacement between the PLT slot and the
12277   // common tail that's part of the special initial PLT slot.
12278   int32_t tail_displacement = (plt_address + (11 * sizeof(uint32_t))
12279                                - (plt_address + plt_offset
12280                                   + sizeof(plt_entry) + sizeof(uint32_t)));
12281   gold_assert((tail_displacement & 3) == 0);
12282   tail_displacement >>= 2;
12283
12284   gold_assert ((tail_displacement & 0xff000000) == 0
12285                || (-tail_displacement & 0xff000000) == 0);
12286
12287   // Calculate the displacement between the PLT slot and the entry
12288   // in the GOT.  The offset accounts for the value produced by
12289   // adding to pc in the penultimate instruction of the PLT stub.
12290   const int32_t got_displacement = (got_address + got_offset
12291                                     - (plt_address + sizeof(plt_entry)));
12292
12293   elfcpp::Swap<32, big_endian>::writeval
12294     (pov + 0, plt_entry[0] | arm_movw_immediate (got_displacement));
12295   elfcpp::Swap<32, big_endian>::writeval
12296     (pov + 4, plt_entry[1] | arm_movt_immediate (got_displacement));
12297   elfcpp::Swap<32, big_endian>::writeval
12298     (pov + 8, plt_entry[2]);
12299   elfcpp::Swap<32, big_endian>::writeval
12300     (pov + 12, plt_entry[3] | (tail_displacement & 0x00ffffff));
12301 }
12302
12303 // Target selectors.
12304
12305 template<bool big_endian>
12306 class Target_selector_arm_nacl
12307   : public Target_selector_nacl<Target_selector_arm<big_endian>,
12308                                 Target_arm_nacl<big_endian> >
12309 {
12310  public:
12311   Target_selector_arm_nacl()
12312     : Target_selector_nacl<Target_selector_arm<big_endian>,
12313                            Target_arm_nacl<big_endian> >(
12314           "arm",
12315           big_endian ? "elf32-bigarm-nacl" : "elf32-littlearm-nacl",
12316           big_endian ? "armelfb_nacl" : "armelf_nacl")
12317   { }
12318 };
12319
12320 Target_selector_arm_nacl<false> target_selector_arm;
12321 Target_selector_arm_nacl<true> target_selector_armbe;
12322
12323 } // End anonymous namespace.