* configure.ac (ENABLE_GOLD): Consider *-*-nacl* targets ELF.
[external/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   // Relocate a section during a relocatable link.
2290   void
2291   relocate_for_relocatable(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                            off_t offset_in_output_section,
2297                            const Relocatable_relocs*,
2298                            unsigned char* view,
2299                            Arm_address view_address,
2300                            section_size_type view_size,
2301                            unsigned char* reloc_view,
2302                            section_size_type reloc_view_size);
2303
2304   // Perform target-specific processing in a relocatable link.  This is
2305   // only used if we use the relocation strategy RELOC_SPECIAL.
2306   void
2307   relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2308                                unsigned int sh_type,
2309                                const unsigned char* preloc_in,
2310                                size_t relnum,
2311                                Output_section* output_section,
2312                                off_t offset_in_output_section,
2313                                unsigned char* view,
2314                                typename elfcpp::Elf_types<32>::Elf_Addr
2315                                  view_address,
2316                                section_size_type view_size,
2317                                unsigned char* preloc_out);
2318
2319   // Return whether SYM is defined by the ABI.
2320   bool
2321   do_is_defined_by_abi(const Symbol* sym) const
2322   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2323
2324   // Return whether there is a GOT section.
2325   bool
2326   has_got_section() const
2327   { return this->got_ != NULL; }
2328
2329   // Return the size of the GOT section.
2330   section_size_type
2331   got_size() const
2332   {
2333     gold_assert(this->got_ != NULL);
2334     return this->got_->data_size();
2335   }
2336
2337   // Return the number of entries in the GOT.
2338   unsigned int
2339   got_entry_count() const
2340   {
2341     if (!this->has_got_section())
2342       return 0;
2343     return this->got_size() / 4;
2344   }
2345
2346   // Return the number of entries in the PLT.
2347   unsigned int
2348   plt_entry_count() const;
2349
2350   // Return the offset of the first non-reserved PLT entry.
2351   unsigned int
2352   first_plt_entry_offset() const;
2353
2354   // Return the size of each PLT entry.
2355   unsigned int
2356   plt_entry_size() const;
2357
2358   // Map platform-specific reloc types
2359   static unsigned int
2360   get_real_reloc_type(unsigned int r_type);
2361
2362   //
2363   // Methods to support stub-generations.
2364   //
2365
2366   // Return the stub factory
2367   const Stub_factory&
2368   stub_factory() const
2369   { return this->stub_factory_; }
2370
2371   // Make a new Arm_input_section object.
2372   Arm_input_section<big_endian>*
2373   new_arm_input_section(Relobj*, unsigned int);
2374
2375   // Find the Arm_input_section object corresponding to the SHNDX-th input
2376   // section of RELOBJ.
2377   Arm_input_section<big_endian>*
2378   find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2379
2380   // Make a new Stub_table
2381   Stub_table<big_endian>*
2382   new_stub_table(Arm_input_section<big_endian>*);
2383
2384   // Scan a section for stub generation.
2385   void
2386   scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2387                          const unsigned char*, size_t, Output_section*,
2388                          bool, const unsigned char*, Arm_address,
2389                          section_size_type);
2390
2391   // Relocate a stub.
2392   void
2393   relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2394                 Output_section*, unsigned char*, Arm_address,
2395                 section_size_type);
2396
2397   // Get the default ARM target.
2398   static Target_arm<big_endian>*
2399   default_target()
2400   {
2401     gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2402                 && parameters->target().is_big_endian() == big_endian);
2403     return static_cast<Target_arm<big_endian>*>(
2404              parameters->sized_target<32, big_endian>());
2405   }
2406
2407   // Whether NAME belongs to a mapping symbol.
2408   static bool
2409   is_mapping_symbol_name(const char* name)
2410   {
2411     return (name
2412             && name[0] == '$'
2413             && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2414             && (name[2] == '\0' || name[2] == '.'));
2415   }
2416
2417   // Whether we work around the Cortex-A8 erratum.
2418   bool
2419   fix_cortex_a8() const
2420   { return this->fix_cortex_a8_; }
2421
2422   // Whether we merge exidx entries in debuginfo.
2423   bool
2424   merge_exidx_entries() const
2425   { return parameters->options().merge_exidx_entries(); }
2426
2427   // Whether we fix R_ARM_V4BX relocation.
2428   // 0 - do not fix
2429   // 1 - replace with MOV instruction (armv4 target)
2430   // 2 - make interworking veneer (>= armv4t targets only)
2431   General_options::Fix_v4bx
2432   fix_v4bx() const
2433   { return parameters->options().fix_v4bx(); }
2434
2435   // Scan a span of THUMB code section for Cortex-A8 erratum.
2436   void
2437   scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2438                                   section_size_type, section_size_type,
2439                                   const unsigned char*, Arm_address);
2440
2441   // Apply Cortex-A8 workaround to a branch.
2442   void
2443   apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2444                              unsigned char*, Arm_address);
2445
2446  protected:
2447   // Make the PLT-generator object.
2448   Output_data_plt_arm<big_endian>*
2449   make_data_plt(Layout* layout, Output_data_space* got_plt)
2450   { return this->do_make_data_plt(layout, got_plt); }
2451
2452   // Make an ELF object.
2453   Object*
2454   do_make_elf_object(const std::string&, Input_file*, off_t,
2455                      const elfcpp::Ehdr<32, big_endian>& ehdr);
2456
2457   Object*
2458   do_make_elf_object(const std::string&, Input_file*, off_t,
2459                      const elfcpp::Ehdr<32, !big_endian>&)
2460   { gold_unreachable(); }
2461
2462   Object*
2463   do_make_elf_object(const std::string&, Input_file*, off_t,
2464                       const elfcpp::Ehdr<64, false>&)
2465   { gold_unreachable(); }
2466
2467   Object*
2468   do_make_elf_object(const std::string&, Input_file*, off_t,
2469                      const elfcpp::Ehdr<64, true>&)
2470   { gold_unreachable(); }
2471
2472   // Make an output section.
2473   Output_section*
2474   do_make_output_section(const char* name, elfcpp::Elf_Word type,
2475                          elfcpp::Elf_Xword flags)
2476   { return new Arm_output_section<big_endian>(name, type, flags); }
2477
2478   void
2479   do_adjust_elf_header(unsigned char* view, int len) const;
2480
2481   // We only need to generate stubs, and hence perform relaxation if we are
2482   // not doing relocatable linking.
2483   bool
2484   do_may_relax() const
2485   { return !parameters->options().relocatable(); }
2486
2487   bool
2488   do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
2489
2490   // Determine whether an object attribute tag takes an integer, a
2491   // string or both.
2492   int
2493   do_attribute_arg_type(int tag) const;
2494
2495   // Reorder tags during output.
2496   int
2497   do_attributes_order(int num) const;
2498
2499   // This is called when the target is selected as the default.
2500   void
2501   do_select_as_default_target()
2502   {
2503     // No locking is required since there should only be one default target.
2504     // We cannot have both the big-endian and little-endian ARM targets
2505     // as the default.
2506     gold_assert(arm_reloc_property_table == NULL);
2507     arm_reloc_property_table = new Arm_reloc_property_table();
2508   }
2509
2510   // Virtual function which is set to return true by a target if
2511   // it can use relocation types to determine if a function's
2512   // pointer is taken.
2513   virtual bool
2514   do_can_check_for_function_pointers() const
2515   { return true; }
2516
2517   // Whether a section called SECTION_NAME may have function pointers to
2518   // sections not eligible for safe ICF folding.
2519   virtual bool
2520   do_section_may_have_icf_unsafe_pointers(const char* section_name) const
2521   {
2522     return (!is_prefix_of(".ARM.exidx", section_name)
2523             && !is_prefix_of(".ARM.extab", section_name)
2524             && Target::do_section_may_have_icf_unsafe_pointers(section_name));
2525   }
2526
2527   virtual void
2528   do_define_standard_symbols(Symbol_table*, Layout*);
2529
2530   virtual Output_data_plt_arm<big_endian>*
2531   do_make_data_plt(Layout* layout, Output_data_space* got_plt)
2532   {
2533     return new Output_data_plt_arm_standard<big_endian>(layout, got_plt);
2534   }
2535
2536  private:
2537   // The class which scans relocations.
2538   class Scan
2539   {
2540    public:
2541     Scan()
2542       : issued_non_pic_error_(false)
2543     { }
2544
2545     static inline int
2546     get_reference_flags(unsigned int r_type);
2547
2548     inline void
2549     local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2550           Sized_relobj_file<32, big_endian>* object,
2551           unsigned int data_shndx,
2552           Output_section* output_section,
2553           const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2554           const elfcpp::Sym<32, big_endian>& lsym);
2555
2556     inline void
2557     global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2558            Sized_relobj_file<32, big_endian>* object,
2559            unsigned int data_shndx,
2560            Output_section* output_section,
2561            const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2562            Symbol* gsym);
2563
2564     inline bool
2565     local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2566                                         Sized_relobj_file<32, big_endian>* ,
2567                                         unsigned int ,
2568                                         Output_section* ,
2569                                         const elfcpp::Rel<32, big_endian>& ,
2570                                         unsigned int ,
2571                                         const elfcpp::Sym<32, big_endian>&);
2572
2573     inline bool
2574     global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2575                                          Sized_relobj_file<32, big_endian>* ,
2576                                          unsigned int ,
2577                                          Output_section* ,
2578                                          const elfcpp::Rel<32, big_endian>& ,
2579                                          unsigned int , Symbol*);
2580
2581    private:
2582     static void
2583     unsupported_reloc_local(Sized_relobj_file<32, big_endian>*,
2584                             unsigned int r_type);
2585
2586     static void
2587     unsupported_reloc_global(Sized_relobj_file<32, big_endian>*,
2588                              unsigned int r_type, Symbol*);
2589
2590     void
2591     check_non_pic(Relobj*, unsigned int r_type);
2592
2593     // Almost identical to Symbol::needs_plt_entry except that it also
2594     // handles STT_ARM_TFUNC.
2595     static bool
2596     symbol_needs_plt_entry(const Symbol* sym)
2597     {
2598       // An undefined symbol from an executable does not need a PLT entry.
2599       if (sym->is_undefined() && !parameters->options().shared())
2600         return false;
2601
2602       return (!parameters->doing_static_link()
2603               && (sym->type() == elfcpp::STT_FUNC
2604                   || sym->type() == elfcpp::STT_ARM_TFUNC)
2605               && (sym->is_from_dynobj()
2606                   || sym->is_undefined()
2607                   || sym->is_preemptible()));
2608     }
2609
2610     inline bool
2611     possible_function_pointer_reloc(unsigned int r_type);
2612
2613     // Whether we have issued an error about a non-PIC compilation.
2614     bool issued_non_pic_error_;
2615   };
2616
2617   // The class which implements relocation.
2618   class Relocate
2619   {
2620    public:
2621     Relocate()
2622     { }
2623
2624     ~Relocate()
2625     { }
2626
2627     // Return whether the static relocation needs to be applied.
2628     inline bool
2629     should_apply_static_reloc(const Sized_symbol<32>* gsym,
2630                               unsigned int r_type,
2631                               bool is_32bit,
2632                               Output_section* output_section);
2633
2634     // Do a relocation.  Return false if the caller should not issue
2635     // any warnings about this relocation.
2636     inline bool
2637     relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2638              Output_section*,  size_t relnum,
2639              const elfcpp::Rel<32, big_endian>&,
2640              unsigned int r_type, const Sized_symbol<32>*,
2641              const Symbol_value<32>*,
2642              unsigned char*, Arm_address,
2643              section_size_type);
2644
2645     // Return whether we want to pass flag NON_PIC_REF for this
2646     // reloc.  This means the relocation type accesses a symbol not via
2647     // GOT or PLT.
2648     static inline bool
2649     reloc_is_non_pic(unsigned int r_type)
2650     {
2651       switch (r_type)
2652         {
2653         // These relocation types reference GOT or PLT entries explicitly.
2654         case elfcpp::R_ARM_GOT_BREL:
2655         case elfcpp::R_ARM_GOT_ABS:
2656         case elfcpp::R_ARM_GOT_PREL:
2657         case elfcpp::R_ARM_GOT_BREL12:
2658         case elfcpp::R_ARM_PLT32_ABS:
2659         case elfcpp::R_ARM_TLS_GD32:
2660         case elfcpp::R_ARM_TLS_LDM32:
2661         case elfcpp::R_ARM_TLS_IE32:
2662         case elfcpp::R_ARM_TLS_IE12GP:
2663
2664         // These relocate types may use PLT entries.
2665         case elfcpp::R_ARM_CALL:
2666         case elfcpp::R_ARM_THM_CALL:
2667         case elfcpp::R_ARM_JUMP24:
2668         case elfcpp::R_ARM_THM_JUMP24:
2669         case elfcpp::R_ARM_THM_JUMP19:
2670         case elfcpp::R_ARM_PLT32:
2671         case elfcpp::R_ARM_THM_XPC22:
2672         case elfcpp::R_ARM_PREL31:
2673         case elfcpp::R_ARM_SBREL31:
2674           return false;
2675
2676         default:
2677           return true;
2678         }
2679     }
2680
2681    private:
2682     // Do a TLS relocation.
2683     inline typename Arm_relocate_functions<big_endian>::Status
2684     relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2685                  size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2686                  const Sized_symbol<32>*, const Symbol_value<32>*,
2687                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2688                  section_size_type);
2689
2690   };
2691
2692   // A class which returns the size required for a relocation type,
2693   // used while scanning relocs during a relocatable link.
2694   class Relocatable_size_for_reloc
2695   {
2696    public:
2697     unsigned int
2698     get_size_for_reloc(unsigned int, Relobj*);
2699   };
2700
2701   // Adjust TLS relocation type based on the options and whether this
2702   // is a local symbol.
2703   static tls::Tls_optimization
2704   optimize_tls_reloc(bool is_final, int r_type);
2705
2706   // Get the GOT section, creating it if necessary.
2707   Arm_output_data_got<big_endian>*
2708   got_section(Symbol_table*, Layout*);
2709
2710   // Get the GOT PLT section.
2711   Output_data_space*
2712   got_plt_section() const
2713   {
2714     gold_assert(this->got_plt_ != NULL);
2715     return this->got_plt_;
2716   }
2717
2718   // Create a PLT entry for a global symbol.
2719   void
2720   make_plt_entry(Symbol_table*, Layout*, Symbol*);
2721
2722   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2723   void
2724   define_tls_base_symbol(Symbol_table*, Layout*);
2725
2726   // Create a GOT entry for the TLS module index.
2727   unsigned int
2728   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2729                       Sized_relobj_file<32, big_endian>* object);
2730
2731   // Get the PLT section.
2732   const Output_data_plt_arm<big_endian>*
2733   plt_section() const
2734   {
2735     gold_assert(this->plt_ != NULL);
2736     return this->plt_;
2737   }
2738
2739   // Get the dynamic reloc section, creating it if necessary.
2740   Reloc_section*
2741   rel_dyn_section(Layout*);
2742
2743   // Get the section to use for TLS_DESC relocations.
2744   Reloc_section*
2745   rel_tls_desc_section(Layout*) const;
2746
2747   // Return true if the symbol may need a COPY relocation.
2748   // References from an executable object to non-function symbols
2749   // defined in a dynamic object may need a COPY relocation.
2750   bool
2751   may_need_copy_reloc(Symbol* gsym)
2752   {
2753     return (gsym->type() != elfcpp::STT_ARM_TFUNC
2754             && gsym->may_need_copy_reloc());
2755   }
2756
2757   // Add a potential copy relocation.
2758   void
2759   copy_reloc(Symbol_table* symtab, Layout* layout,
2760              Sized_relobj_file<32, big_endian>* object,
2761              unsigned int shndx, Output_section* output_section,
2762              Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2763   {
2764     this->copy_relocs_.copy_reloc(symtab, layout,
2765                                   symtab->get_sized_symbol<32>(sym),
2766                                   object, shndx, output_section, reloc,
2767                                   this->rel_dyn_section(layout));
2768   }
2769
2770   // Whether two EABI versions are compatible.
2771   static bool
2772   are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2773
2774   // Merge processor-specific flags from input object and those in the ELF
2775   // header of the output.
2776   void
2777   merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2778
2779   // Get the secondary compatible architecture.
2780   static int
2781   get_secondary_compatible_arch(const Attributes_section_data*);
2782
2783   // Set the secondary compatible architecture.
2784   static void
2785   set_secondary_compatible_arch(Attributes_section_data*, int);
2786
2787   static int
2788   tag_cpu_arch_combine(const char*, int, int*, int, int);
2789
2790   // Helper to print AEABI enum tag value.
2791   static std::string
2792   aeabi_enum_name(unsigned int);
2793
2794   // Return string value for TAG_CPU_name.
2795   static std::string
2796   tag_cpu_name_value(unsigned int);
2797
2798   // Merge object attributes from input object and those in the output.
2799   void
2800   merge_object_attributes(const char*, const Attributes_section_data*);
2801
2802   // Helper to get an AEABI object attribute
2803   Object_attribute*
2804   get_aeabi_object_attribute(int tag) const
2805   {
2806     Attributes_section_data* pasd = this->attributes_section_data_;
2807     gold_assert(pasd != NULL);
2808     Object_attribute* attr =
2809       pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2810     gold_assert(attr != NULL);
2811     return attr;
2812   }
2813
2814   //
2815   // Methods to support stub-generations.
2816   //
2817
2818   // Group input sections for stub generation.
2819   void
2820   group_sections(Layout*, section_size_type, bool, const Task*);
2821
2822   // Scan a relocation for stub generation.
2823   void
2824   scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2825                       const Sized_symbol<32>*, unsigned int,
2826                       const Symbol_value<32>*,
2827                       elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2828
2829   // Scan a relocation section for stub.
2830   template<int sh_type>
2831   void
2832   scan_reloc_section_for_stubs(
2833       const Relocate_info<32, big_endian>* relinfo,
2834       const unsigned char* prelocs,
2835       size_t reloc_count,
2836       Output_section* output_section,
2837       bool needs_special_offset_handling,
2838       const unsigned char* view,
2839       elfcpp::Elf_types<32>::Elf_Addr view_address,
2840       section_size_type);
2841
2842   // Fix .ARM.exidx section coverage.
2843   void
2844   fix_exidx_coverage(Layout*, const Input_objects*,
2845                      Arm_output_section<big_endian>*, Symbol_table*,
2846                      const Task*);
2847
2848   // Functors for STL set.
2849   struct output_section_address_less_than
2850   {
2851     bool
2852     operator()(const Output_section* s1, const Output_section* s2) const
2853     { return s1->address() < s2->address(); }
2854   };
2855
2856   // Information about this specific target which we pass to the
2857   // general Target structure.
2858   static const Target::Target_info arm_info;
2859
2860   // The types of GOT entries needed for this platform.
2861   // These values are exposed to the ABI in an incremental link.
2862   // Do not renumber existing values without changing the version
2863   // number of the .gnu_incremental_inputs section.
2864   enum Got_type
2865   {
2866     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
2867     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
2868     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
2869     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
2870     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
2871   };
2872
2873   typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2874
2875   // Map input section to Arm_input_section.
2876   typedef Unordered_map<Section_id,
2877                         Arm_input_section<big_endian>*,
2878                         Section_id_hash>
2879           Arm_input_section_map;
2880
2881   // Map output addresses to relocs for Cortex-A8 erratum.
2882   typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2883           Cortex_a8_relocs_info;
2884
2885   // The GOT section.
2886   Arm_output_data_got<big_endian>* got_;
2887   // The PLT section.
2888   Output_data_plt_arm<big_endian>* plt_;
2889   // The GOT PLT section.
2890   Output_data_space* got_plt_;
2891   // The dynamic reloc section.
2892   Reloc_section* rel_dyn_;
2893   // Relocs saved to avoid a COPY reloc.
2894   Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2895   // Space for variables copied with a COPY reloc.
2896   Output_data_space* dynbss_;
2897   // Offset of the GOT entry for the TLS module index.
2898   unsigned int got_mod_index_offset_;
2899   // True if the _TLS_MODULE_BASE_ symbol has been defined.
2900   bool tls_base_symbol_defined_;
2901   // Vector of Stub_tables created.
2902   Stub_table_list stub_tables_;
2903   // Stub factory.
2904   const Stub_factory &stub_factory_;
2905   // Whether we force PIC branch veneers.
2906   bool should_force_pic_veneer_;
2907   // Map for locating Arm_input_sections.
2908   Arm_input_section_map arm_input_section_map_;
2909   // Attributes section data in output.
2910   Attributes_section_data* attributes_section_data_;
2911   // Whether we want to fix code for Cortex-A8 erratum.
2912   bool fix_cortex_a8_;
2913   // Map addresses to relocs for Cortex-A8 erratum.
2914   Cortex_a8_relocs_info cortex_a8_relocs_info_;
2915 };
2916
2917 template<bool big_endian>
2918 const Target::Target_info Target_arm<big_endian>::arm_info =
2919 {
2920   32,                   // size
2921   big_endian,           // is_big_endian
2922   elfcpp::EM_ARM,       // machine_code
2923   false,                // has_make_symbol
2924   false,                // has_resolve
2925   false,                // has_code_fill
2926   true,                 // is_default_stack_executable
2927   false,                // can_icf_inline_merge_sections
2928   '\0',                 // wrap_char
2929   "/usr/lib/libc.so.1", // dynamic_linker
2930   0x8000,               // default_text_segment_address
2931   0x1000,               // abi_pagesize (overridable by -z max-page-size)
2932   0x1000,               // common_pagesize (overridable by -z common-page-size)
2933   false,                // isolate_execinstr
2934   0,                    // rosegment_gap
2935   elfcpp::SHN_UNDEF,    // small_common_shndx
2936   elfcpp::SHN_UNDEF,    // large_common_shndx
2937   0,                    // small_common_section_flags
2938   0,                    // large_common_section_flags
2939   ".ARM.attributes",    // attributes_section
2940   "aeabi"               // attributes_vendor
2941 };
2942
2943 // Arm relocate functions class
2944 //
2945
2946 template<bool big_endian>
2947 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2948 {
2949  public:
2950   typedef enum
2951   {
2952     STATUS_OKAY,        // No error during relocation.
2953     STATUS_OVERFLOW,    // Relocation overflow.
2954     STATUS_BAD_RELOC    // Relocation cannot be applied.
2955   } Status;
2956
2957  private:
2958   typedef Relocate_functions<32, big_endian> Base;
2959   typedef Arm_relocate_functions<big_endian> This;
2960
2961   // Encoding of imm16 argument for movt and movw ARM instructions
2962   // from ARM ARM:
2963   //
2964   //     imm16 := imm4 | imm12
2965   //
2966   //  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
2967   // +-------+---------------+-------+-------+-----------------------+
2968   // |       |               |imm4   |       |imm12                  |
2969   // +-------+---------------+-------+-------+-----------------------+
2970
2971   // Extract the relocation addend from VAL based on the ARM
2972   // instruction encoding described above.
2973   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2974   extract_arm_movw_movt_addend(
2975       typename elfcpp::Swap<32, big_endian>::Valtype val)
2976   {
2977     // According to the Elf ABI for ARM Architecture the immediate
2978     // field is sign-extended to form the addend.
2979     return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff));
2980   }
2981
2982   // Insert X into VAL based on the ARM instruction encoding described
2983   // above.
2984   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2985   insert_val_arm_movw_movt(
2986       typename elfcpp::Swap<32, big_endian>::Valtype val,
2987       typename elfcpp::Swap<32, big_endian>::Valtype x)
2988   {
2989     val &= 0xfff0f000;
2990     val |= x & 0x0fff;
2991     val |= (x & 0xf000) << 4;
2992     return val;
2993   }
2994
2995   // Encoding of imm16 argument for movt and movw Thumb2 instructions
2996   // from ARM ARM:
2997   //
2998   //     imm16 := imm4 | i | imm3 | imm8
2999   //
3000   //  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
3001   // +---------+-+-----------+-------++-+-----+-------+---------------+
3002   // |         |i|           |imm4   || |imm3 |       |imm8           |
3003   // +---------+-+-----------+-------++-+-----+-------+---------------+
3004
3005   // Extract the relocation addend from VAL based on the Thumb2
3006   // instruction encoding described above.
3007   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3008   extract_thumb_movw_movt_addend(
3009       typename elfcpp::Swap<32, big_endian>::Valtype val)
3010   {
3011     // According to the Elf ABI for ARM Architecture the immediate
3012     // field is sign-extended to form the addend.
3013     return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
3014                                    | ((val >> 15) & 0x0800)
3015                                    | ((val >> 4) & 0x0700)
3016                                    | (val & 0x00ff));
3017   }
3018
3019   // Insert X into VAL based on the Thumb2 instruction encoding
3020   // described above.
3021   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3022   insert_val_thumb_movw_movt(
3023       typename elfcpp::Swap<32, big_endian>::Valtype val,
3024       typename elfcpp::Swap<32, big_endian>::Valtype x)
3025   {
3026     val &= 0xfbf08f00;
3027     val |= (x & 0xf000) << 4;
3028     val |= (x & 0x0800) << 15;
3029     val |= (x & 0x0700) << 4;
3030     val |= (x & 0x00ff);
3031     return val;
3032   }
3033
3034   // Calculate the smallest constant Kn for the specified residual.
3035   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3036   static uint32_t
3037   calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3038   {
3039     int32_t msb;
3040
3041     if (residual == 0)
3042       return 0;
3043     // Determine the most significant bit in the residual and
3044     // align the resulting value to a 2-bit boundary.
3045     for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3046       ;
3047     // The desired shift is now (msb - 6), or zero, whichever
3048     // is the greater.
3049     return (((msb - 6) < 0) ? 0 : (msb - 6));
3050   }
3051
3052   // Calculate the final residual for the specified group index.
3053   // If the passed group index is less than zero, the method will return
3054   // the value of the specified residual without any change.
3055   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3056   static typename elfcpp::Swap<32, big_endian>::Valtype
3057   calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3058                     const int group)
3059   {
3060     for (int n = 0; n <= group; n++)
3061       {
3062         // Calculate which part of the value to mask.
3063         uint32_t shift = calc_grp_kn(residual);
3064         // Calculate the residual for the next time around.
3065         residual &= ~(residual & (0xff << shift));
3066       }
3067
3068     return residual;
3069   }
3070
3071   // Calculate the value of Gn for the specified group index.
3072   // We return it in the form of an encoded constant-and-rotation.
3073   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3074   static typename elfcpp::Swap<32, big_endian>::Valtype
3075   calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3076               const int group)
3077   {
3078     typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3079     uint32_t shift = 0;
3080
3081     for (int n = 0; n <= group; n++)
3082       {
3083         // Calculate which part of the value to mask.
3084         shift = calc_grp_kn(residual);
3085         // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3086         gn = residual & (0xff << shift);
3087         // Calculate the residual for the next time around.
3088         residual &= ~gn;
3089       }
3090     // Return Gn in the form of an encoded constant-and-rotation.
3091     return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3092   }
3093
3094  public:
3095   // Handle ARM long branches.
3096   static typename This::Status
3097   arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3098                     unsigned char*, const Sized_symbol<32>*,
3099                     const Arm_relobj<big_endian>*, unsigned int,
3100                     const Symbol_value<32>*, Arm_address, Arm_address, bool);
3101
3102   // Handle THUMB long branches.
3103   static typename This::Status
3104   thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3105                       unsigned char*, const Sized_symbol<32>*,
3106                       const Arm_relobj<big_endian>*, unsigned int,
3107                       const Symbol_value<32>*, Arm_address, Arm_address, bool);
3108
3109
3110   // Return the branch offset of a 32-bit THUMB branch.
3111   static inline int32_t
3112   thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3113   {
3114     // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3115     // involving the J1 and J2 bits.
3116     uint32_t s = (upper_insn & (1U << 10)) >> 10;
3117     uint32_t upper = upper_insn & 0x3ffU;
3118     uint32_t lower = lower_insn & 0x7ffU;
3119     uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3120     uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3121     uint32_t i1 = j1 ^ s ? 0 : 1;
3122     uint32_t i2 = j2 ^ s ? 0 : 1;
3123
3124     return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3125                                    | (upper << 12) | (lower << 1));
3126   }
3127
3128   // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3129   // UPPER_INSN is the original upper instruction of the branch.  Caller is
3130   // responsible for overflow checking and BLX offset adjustment.
3131   static inline uint16_t
3132   thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3133   {
3134     uint32_t s = offset < 0 ? 1 : 0;
3135     uint32_t bits = static_cast<uint32_t>(offset);
3136     return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3137   }
3138
3139   // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3140   // LOWER_INSN is the original lower instruction of the branch.  Caller is
3141   // responsible for overflow checking and BLX offset adjustment.
3142   static inline uint16_t
3143   thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3144   {
3145     uint32_t s = offset < 0 ? 1 : 0;
3146     uint32_t bits = static_cast<uint32_t>(offset);
3147     return ((lower_insn & ~0x2fffU)
3148             | ((((bits >> 23) & 1) ^ !s) << 13)
3149             | ((((bits >> 22) & 1) ^ !s) << 11)
3150             | ((bits >> 1) & 0x7ffU));
3151   }
3152
3153   // Return the branch offset of a 32-bit THUMB conditional branch.
3154   static inline int32_t
3155   thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3156   {
3157     uint32_t s = (upper_insn & 0x0400U) >> 10;
3158     uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3159     uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3160     uint32_t lower = (lower_insn & 0x07ffU);
3161     uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3162
3163     return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3164   }
3165
3166   // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3167   // instruction.  UPPER_INSN is the original upper instruction of the branch.
3168   // Caller is responsible for overflow checking.
3169   static inline uint16_t
3170   thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3171   {
3172     uint32_t s = offset < 0 ? 1 : 0;
3173     uint32_t bits = static_cast<uint32_t>(offset);
3174     return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3175   }
3176
3177   // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3178   // instruction.  LOWER_INSN is the original lower instruction of the branch.
3179   // The caller is responsible for overflow checking.
3180   static inline uint16_t
3181   thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3182   {
3183     uint32_t bits = static_cast<uint32_t>(offset);
3184     uint32_t j2 = (bits & 0x00080000U) >> 19;
3185     uint32_t j1 = (bits & 0x00040000U) >> 18;
3186     uint32_t lo = (bits & 0x00000ffeU) >> 1;
3187
3188     return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3189   }
3190
3191   // R_ARM_ABS8: S + A
3192   static inline typename This::Status
3193   abs8(unsigned char* view,
3194        const Sized_relobj_file<32, big_endian>* object,
3195        const Symbol_value<32>* psymval)
3196   {
3197     typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3198     Valtype* wv = reinterpret_cast<Valtype*>(view);
3199     Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3200     int32_t addend = Bits<8>::sign_extend32(val);
3201     Arm_address x = psymval->value(object, addend);
3202     val = Bits<32>::bit_select32(val, x, 0xffU);
3203     elfcpp::Swap<8, big_endian>::writeval(wv, val);
3204
3205     // R_ARM_ABS8 permits signed or unsigned results.
3206     return (Bits<8>::has_signed_unsigned_overflow32(x)
3207             ? This::STATUS_OVERFLOW
3208             : This::STATUS_OKAY);
3209   }
3210
3211   // R_ARM_THM_ABS5: S + A
3212   static inline typename This::Status
3213   thm_abs5(unsigned char* view,
3214        const Sized_relobj_file<32, big_endian>* object,
3215        const Symbol_value<32>* psymval)
3216   {
3217     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3218     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3219     Valtype* wv = reinterpret_cast<Valtype*>(view);
3220     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3221     Reltype addend = (val & 0x7e0U) >> 6;
3222     Reltype x = psymval->value(object, addend);
3223     val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3224     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3225     return (Bits<5>::has_overflow32(x)
3226             ? This::STATUS_OVERFLOW
3227             : This::STATUS_OKAY);
3228   }
3229
3230   // R_ARM_ABS12: S + A
3231   static inline typename This::Status
3232   abs12(unsigned char* view,
3233         const Sized_relobj_file<32, big_endian>* object,
3234         const Symbol_value<32>* psymval)
3235   {
3236     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3237     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3238     Valtype* wv = reinterpret_cast<Valtype*>(view);
3239     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3240     Reltype addend = val & 0x0fffU;
3241     Reltype x = psymval->value(object, addend);
3242     val = Bits<32>::bit_select32(val, x, 0x0fffU);
3243     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3244     return (Bits<12>::has_overflow32(x)
3245             ? This::STATUS_OVERFLOW
3246             : This::STATUS_OKAY);
3247   }
3248
3249   // R_ARM_ABS16: S + A
3250   static inline typename This::Status
3251   abs16(unsigned char* view,
3252         const Sized_relobj_file<32, big_endian>* object,
3253         const Symbol_value<32>* psymval)
3254   {
3255     typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
3256     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3257     Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view);
3258     int32_t addend = Bits<16>::sign_extend32(val);
3259     Arm_address x = psymval->value(object, addend);
3260     val = Bits<32>::bit_select32(val, x, 0xffffU);
3261     elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val);
3262
3263     // R_ARM_ABS16 permits signed or unsigned results.
3264     return (Bits<16>::has_signed_unsigned_overflow32(x)
3265             ? This::STATUS_OVERFLOW
3266             : This::STATUS_OKAY);
3267   }
3268
3269   // R_ARM_ABS32: (S + A) | T
3270   static inline typename This::Status
3271   abs32(unsigned char* view,
3272         const Sized_relobj_file<32, big_endian>* object,
3273         const Symbol_value<32>* psymval,
3274         Arm_address thumb_bit)
3275   {
3276     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3277     Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3278     Valtype x = psymval->value(object, addend) | thumb_bit;
3279     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3280     return This::STATUS_OKAY;
3281   }
3282
3283   // R_ARM_REL32: (S + A) | T - P
3284   static inline typename This::Status
3285   rel32(unsigned char* view,
3286         const Sized_relobj_file<32, big_endian>* object,
3287         const Symbol_value<32>* psymval,
3288         Arm_address address,
3289         Arm_address thumb_bit)
3290   {
3291     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3292     Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3293     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3294     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3295     return This::STATUS_OKAY;
3296   }
3297
3298   // R_ARM_THM_JUMP24: (S + A) | T - P
3299   static typename This::Status
3300   thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3301              const Symbol_value<32>* psymval, Arm_address address,
3302              Arm_address thumb_bit);
3303
3304   // R_ARM_THM_JUMP6: S + A â€“ P
3305   static inline typename This::Status
3306   thm_jump6(unsigned char* view,
3307             const Sized_relobj_file<32, big_endian>* object,
3308             const Symbol_value<32>* psymval,
3309             Arm_address address)
3310   {
3311     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3312     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3313     Valtype* wv = reinterpret_cast<Valtype*>(view);
3314     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3315     // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3316     Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3317     Reltype x = (psymval->value(object, addend) - address);
3318     val = (val & 0xfd07) | ((x  & 0x0040) << 3) | ((val & 0x003e) << 2);
3319     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3320     // CZB does only forward jumps.
3321     return ((x > 0x007e)
3322             ? This::STATUS_OVERFLOW
3323             : This::STATUS_OKAY);
3324   }
3325
3326   // R_ARM_THM_JUMP8: S + A â€“ P
3327   static inline typename This::Status
3328   thm_jump8(unsigned char* view,
3329             const Sized_relobj_file<32, big_endian>* object,
3330             const Symbol_value<32>* psymval,
3331             Arm_address address)
3332   {
3333     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3334     Valtype* wv = reinterpret_cast<Valtype*>(view);
3335     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3336     int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1);
3337     int32_t x = (psymval->value(object, addend) - address);
3338     elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00)
3339                                                 | ((x & 0x01fe) >> 1)));
3340     // We do a 9-bit overflow check because x is right-shifted by 1 bit.
3341     return (Bits<9>::has_overflow32(x)
3342             ? This::STATUS_OVERFLOW
3343             : This::STATUS_OKAY);
3344   }
3345
3346   // R_ARM_THM_JUMP11: S + A â€“ P
3347   static inline typename This::Status
3348   thm_jump11(unsigned char* view,
3349             const Sized_relobj_file<32, big_endian>* object,
3350             const Symbol_value<32>* psymval,
3351             Arm_address address)
3352   {
3353     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3354     Valtype* wv = reinterpret_cast<Valtype*>(view);
3355     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3356     int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1);
3357     int32_t x = (psymval->value(object, addend) - address);
3358     elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800)
3359                                                 | ((x & 0x0ffe) >> 1)));
3360     // We do a 12-bit overflow check because x is right-shifted by 1 bit.
3361     return (Bits<12>::has_overflow32(x)
3362             ? This::STATUS_OVERFLOW
3363             : This::STATUS_OKAY);
3364   }
3365
3366   // R_ARM_BASE_PREL: B(S) + A - P
3367   static inline typename This::Status
3368   base_prel(unsigned char* view,
3369             Arm_address origin,
3370             Arm_address address)
3371   {
3372     Base::rel32(view, origin - address);
3373     return STATUS_OKAY;
3374   }
3375
3376   // R_ARM_BASE_ABS: B(S) + A
3377   static inline typename This::Status
3378   base_abs(unsigned char* view,
3379            Arm_address origin)
3380   {
3381     Base::rel32(view, origin);
3382     return STATUS_OKAY;
3383   }
3384
3385   // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3386   static inline typename This::Status
3387   got_brel(unsigned char* view,
3388            typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3389   {
3390     Base::rel32(view, got_offset);
3391     return This::STATUS_OKAY;
3392   }
3393
3394   // R_ARM_GOT_PREL: GOT(S) + A - P
3395   static inline typename This::Status
3396   got_prel(unsigned char* view,
3397            Arm_address got_entry,
3398            Arm_address address)
3399   {
3400     Base::rel32(view, got_entry - address);
3401     return This::STATUS_OKAY;
3402   }
3403
3404   // R_ARM_PREL: (S + A) | T - P
3405   static inline typename This::Status
3406   prel31(unsigned char* view,
3407          const Sized_relobj_file<32, big_endian>* object,
3408          const Symbol_value<32>* psymval,
3409          Arm_address address,
3410          Arm_address thumb_bit)
3411   {
3412     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3413     Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3414     Valtype addend = Bits<31>::sign_extend32(val);
3415     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3416     val = Bits<32>::bit_select32(val, x, 0x7fffffffU);
3417     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val);
3418     return (Bits<31>::has_overflow32(x)
3419             ? This::STATUS_OVERFLOW
3420             : This::STATUS_OKAY);
3421   }
3422
3423   // R_ARM_MOVW_ABS_NC: (S + A) | T     (relative address base is )
3424   // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3425   // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3426   // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3427   static inline typename This::Status
3428   movw(unsigned char* view,
3429        const Sized_relobj_file<32, big_endian>* object,
3430        const Symbol_value<32>* psymval,
3431        Arm_address relative_address_base,
3432        Arm_address thumb_bit,
3433        bool check_overflow)
3434   {
3435     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3436     Valtype* wv = reinterpret_cast<Valtype*>(view);
3437     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3438     Valtype addend = This::extract_arm_movw_movt_addend(val);
3439     Valtype x = ((psymval->value(object, addend) | thumb_bit)
3440                  - relative_address_base);
3441     val = This::insert_val_arm_movw_movt(val, x);
3442     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3443     return ((check_overflow && Bits<16>::has_overflow32(x))
3444             ? This::STATUS_OVERFLOW
3445             : This::STATUS_OKAY);
3446   }
3447
3448   // R_ARM_MOVT_ABS: S + A      (relative address base is 0)
3449   // R_ARM_MOVT_PREL: S + A - P
3450   // R_ARM_MOVT_BREL: S + A - B(S)
3451   static inline typename This::Status
3452   movt(unsigned char* view,
3453        const Sized_relobj_file<32, big_endian>* object,
3454        const Symbol_value<32>* psymval,
3455        Arm_address relative_address_base)
3456   {
3457     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3458     Valtype* wv = reinterpret_cast<Valtype*>(view);
3459     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3460     Valtype addend = This::extract_arm_movw_movt_addend(val);
3461     Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3462     val = This::insert_val_arm_movw_movt(val, x);
3463     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3464     // FIXME: IHI0044D says that we should check for overflow.
3465     return This::STATUS_OKAY;
3466   }
3467
3468   // R_ARM_THM_MOVW_ABS_NC: S + A | T           (relative_address_base is 0)
3469   // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3470   // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3471   // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3472   static inline typename This::Status
3473   thm_movw(unsigned char* view,
3474            const Sized_relobj_file<32, big_endian>* object,
3475            const Symbol_value<32>* psymval,
3476            Arm_address relative_address_base,
3477            Arm_address thumb_bit,
3478            bool check_overflow)
3479   {
3480     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3481     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3482     Valtype* wv = reinterpret_cast<Valtype*>(view);
3483     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3484                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3485     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3486     Reltype x =
3487       (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3488     val = This::insert_val_thumb_movw_movt(val, x);
3489     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3490     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3491     return ((check_overflow && Bits<16>::has_overflow32(x))
3492             ? This::STATUS_OVERFLOW
3493             : This::STATUS_OKAY);
3494   }
3495
3496   // R_ARM_THM_MOVT_ABS: S + A          (relative address base is 0)
3497   // R_ARM_THM_MOVT_PREL: S + A - P
3498   // R_ARM_THM_MOVT_BREL: S + A - B(S)
3499   static inline typename This::Status
3500   thm_movt(unsigned char* view,
3501            const Sized_relobj_file<32, big_endian>* object,
3502            const Symbol_value<32>* psymval,
3503            Arm_address relative_address_base)
3504   {
3505     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3506     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3507     Valtype* wv = reinterpret_cast<Valtype*>(view);
3508     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3509                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3510     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3511     Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3512     val = This::insert_val_thumb_movw_movt(val, x);
3513     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3514     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3515     return This::STATUS_OKAY;
3516   }
3517
3518   // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3519   static inline typename This::Status
3520   thm_alu11(unsigned char* view,
3521             const Sized_relobj_file<32, big_endian>* object,
3522             const Symbol_value<32>* psymval,
3523             Arm_address address,
3524             Arm_address thumb_bit)
3525   {
3526     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3527     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3528     Valtype* wv = reinterpret_cast<Valtype*>(view);
3529     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3530                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3531
3532     //        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
3533     // -----------------------------------------------------------------------
3534     // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd     |imm8
3535     // ADDW   1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd     |imm8
3536     // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd     |imm8
3537     // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd     |imm8
3538     // SUBW   1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd     |imm8
3539     // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd     |imm8
3540
3541     // Determine a sign for the addend.
3542     const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3543                       || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3544     // Thumb2 addend encoding:
3545     // imm12 := i | imm3 | imm8
3546     int32_t addend = (insn & 0xff)
3547                      | ((insn & 0x00007000) >> 4)
3548                      | ((insn & 0x04000000) >> 15);
3549     // Apply a sign to the added.
3550     addend *= sign;
3551
3552     int32_t x = (psymval->value(object, addend) | thumb_bit)
3553                 - (address & 0xfffffffc);
3554     Reltype val = abs(x);
3555     // Mask out the value and a distinct part of the ADD/SUB opcode
3556     // (bits 7:5 of opword).
3557     insn = (insn & 0xfb0f8f00)
3558            | (val & 0xff)
3559            | ((val & 0x700) << 4)
3560            | ((val & 0x800) << 15);
3561     // Set the opcode according to whether the value to go in the
3562     // place is negative.
3563     if (x < 0)
3564       insn |= 0x00a00000;
3565
3566     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3567     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3568     return ((val > 0xfff) ?
3569             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3570   }
3571
3572   // R_ARM_THM_PC8: S + A - Pa (Thumb)
3573   static inline typename This::Status
3574   thm_pc8(unsigned char* view,
3575           const Sized_relobj_file<32, big_endian>* object,
3576           const Symbol_value<32>* psymval,
3577           Arm_address address)
3578   {
3579     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3580     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3581     Valtype* wv = reinterpret_cast<Valtype*>(view);
3582     Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3583     Reltype addend = ((insn & 0x00ff) << 2);
3584     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3585     Reltype val = abs(x);
3586     insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3587
3588     elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3589     return ((val > 0x03fc)
3590             ? This::STATUS_OVERFLOW
3591             : This::STATUS_OKAY);
3592   }
3593
3594   // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3595   static inline typename This::Status
3596   thm_pc12(unsigned char* view,
3597            const Sized_relobj_file<32, big_endian>* object,
3598            const Symbol_value<32>* psymval,
3599            Arm_address address)
3600   {
3601     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3602     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3603     Valtype* wv = reinterpret_cast<Valtype*>(view);
3604     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3605                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3606     // Determine a sign for the addend (positive if the U bit is 1).
3607     const int sign = (insn & 0x00800000) ? 1 : -1;
3608     int32_t addend = (insn & 0xfff);
3609     // Apply a sign to the added.
3610     addend *= sign;
3611
3612     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3613     Reltype val = abs(x);
3614     // Mask out and apply the value and the U bit.
3615     insn = (insn & 0xff7ff000) | (val & 0xfff);
3616     // Set the U bit according to whether the value to go in the
3617     // place is positive.
3618     if (x >= 0)
3619       insn |= 0x00800000;
3620
3621     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3622     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3623     return ((val > 0xfff) ?
3624             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3625   }
3626
3627   // R_ARM_V4BX
3628   static inline typename This::Status
3629   v4bx(const Relocate_info<32, big_endian>* relinfo,
3630        unsigned char* view,
3631        const Arm_relobj<big_endian>* object,
3632        const Arm_address address,
3633        const bool is_interworking)
3634   {
3635
3636     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3637     Valtype* wv = reinterpret_cast<Valtype*>(view);
3638     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3639
3640     // Ensure that we have a BX instruction.
3641     gold_assert((val & 0x0ffffff0) == 0x012fff10);
3642     const uint32_t reg = (val & 0xf);
3643     if (is_interworking && reg != 0xf)
3644       {
3645         Stub_table<big_endian>* stub_table =
3646             object->stub_table(relinfo->data_shndx);
3647         gold_assert(stub_table != NULL);
3648
3649         Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3650         gold_assert(stub != NULL);
3651
3652         int32_t veneer_address =
3653             stub_table->address() + stub->offset() - 8 - address;
3654         gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3655                     && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3656         // Replace with a branch to veneer (B <addr>)
3657         val = (val & 0xf0000000) | 0x0a000000
3658               | ((veneer_address >> 2) & 0x00ffffff);
3659       }
3660     else
3661       {
3662         // Preserve Rm (lowest four bits) and the condition code
3663         // (highest four bits). Other bits encode MOV PC,Rm.
3664         val = (val & 0xf000000f) | 0x01a0f000;
3665       }
3666     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3667     return This::STATUS_OKAY;
3668   }
3669
3670   // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3671   // R_ARM_ALU_PC_G0:    ((S + A) | T) - P
3672   // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3673   // R_ARM_ALU_PC_G1:    ((S + A) | T) - P
3674   // R_ARM_ALU_PC_G2:    ((S + A) | T) - P
3675   // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3676   // R_ARM_ALU_SB_G0:    ((S + A) | T) - B(S)
3677   // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3678   // R_ARM_ALU_SB_G1:    ((S + A) | T) - B(S)
3679   // R_ARM_ALU_SB_G2:    ((S + A) | T) - B(S)
3680   static inline typename This::Status
3681   arm_grp_alu(unsigned char* view,
3682         const Sized_relobj_file<32, big_endian>* object,
3683         const Symbol_value<32>* psymval,
3684         const int group,
3685         Arm_address address,
3686         Arm_address thumb_bit,
3687         bool check_overflow)
3688   {
3689     gold_assert(group >= 0 && group < 3);
3690     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3691     Valtype* wv = reinterpret_cast<Valtype*>(view);
3692     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3693
3694     // ALU group relocations are allowed only for the ADD/SUB instructions.
3695     // (0x00800000 - ADD, 0x00400000 - SUB)
3696     const Valtype opcode = insn & 0x01e00000;
3697     if (opcode != 0x00800000 && opcode != 0x00400000)
3698       return This::STATUS_BAD_RELOC;
3699
3700     // Determine a sign for the addend.
3701     const int sign = (opcode == 0x00800000) ? 1 : -1;
3702     // shifter = rotate_imm * 2
3703     const uint32_t shifter = (insn & 0xf00) >> 7;
3704     // Initial addend value.
3705     int32_t addend = insn & 0xff;
3706     // Rotate addend right by shifter.
3707     addend = (addend >> shifter) | (addend << (32 - shifter));
3708     // Apply a sign to the added.
3709     addend *= sign;
3710
3711     int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3712     Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3713     // Check for overflow if required
3714     if (check_overflow
3715         && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3716       return This::STATUS_OVERFLOW;
3717
3718     // Mask out the value and the ADD/SUB part of the opcode; take care
3719     // not to destroy the S bit.
3720     insn &= 0xff1ff000;
3721     // Set the opcode according to whether the value to go in the
3722     // place is negative.
3723     insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3724     // Encode the offset (encoded Gn).
3725     insn |= gn;
3726
3727     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3728     return This::STATUS_OKAY;
3729   }
3730
3731   // R_ARM_LDR_PC_G0: S + A - P
3732   // R_ARM_LDR_PC_G1: S + A - P
3733   // R_ARM_LDR_PC_G2: S + A - P
3734   // R_ARM_LDR_SB_G0: S + A - B(S)
3735   // R_ARM_LDR_SB_G1: S + A - B(S)
3736   // R_ARM_LDR_SB_G2: S + A - B(S)
3737   static inline typename This::Status
3738   arm_grp_ldr(unsigned char* view,
3739         const Sized_relobj_file<32, big_endian>* object,
3740         const Symbol_value<32>* psymval,
3741         const int group,
3742         Arm_address address)
3743   {
3744     gold_assert(group >= 0 && group < 3);
3745     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3746     Valtype* wv = reinterpret_cast<Valtype*>(view);
3747     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3748
3749     const int sign = (insn & 0x00800000) ? 1 : -1;
3750     int32_t addend = (insn & 0xfff) * sign;
3751     int32_t x = (psymval->value(object, addend) - address);
3752     // Calculate the relevant G(n-1) value to obtain this stage residual.
3753     Valtype residual =
3754         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3755     if (residual >= 0x1000)
3756       return This::STATUS_OVERFLOW;
3757
3758     // Mask out the value and U bit.
3759     insn &= 0xff7ff000;
3760     // Set the U bit for non-negative values.
3761     if (x >= 0)
3762       insn |= 0x00800000;
3763     insn |= residual;
3764
3765     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3766     return This::STATUS_OKAY;
3767   }
3768
3769   // R_ARM_LDRS_PC_G0: S + A - P
3770   // R_ARM_LDRS_PC_G1: S + A - P
3771   // R_ARM_LDRS_PC_G2: S + A - P
3772   // R_ARM_LDRS_SB_G0: S + A - B(S)
3773   // R_ARM_LDRS_SB_G1: S + A - B(S)
3774   // R_ARM_LDRS_SB_G2: S + A - B(S)
3775   static inline typename This::Status
3776   arm_grp_ldrs(unsigned char* view,
3777         const Sized_relobj_file<32, big_endian>* object,
3778         const Symbol_value<32>* psymval,
3779         const int group,
3780         Arm_address address)
3781   {
3782     gold_assert(group >= 0 && group < 3);
3783     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3784     Valtype* wv = reinterpret_cast<Valtype*>(view);
3785     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3786
3787     const int sign = (insn & 0x00800000) ? 1 : -1;
3788     int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3789     int32_t x = (psymval->value(object, addend) - address);
3790     // Calculate the relevant G(n-1) value to obtain this stage residual.
3791     Valtype residual =
3792         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3793    if (residual >= 0x100)
3794       return This::STATUS_OVERFLOW;
3795
3796     // Mask out the value and U bit.
3797     insn &= 0xff7ff0f0;
3798     // Set the U bit for non-negative values.
3799     if (x >= 0)
3800       insn |= 0x00800000;
3801     insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3802
3803     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3804     return This::STATUS_OKAY;
3805   }
3806
3807   // R_ARM_LDC_PC_G0: S + A - P
3808   // R_ARM_LDC_PC_G1: S + A - P
3809   // R_ARM_LDC_PC_G2: S + A - P
3810   // R_ARM_LDC_SB_G0: S + A - B(S)
3811   // R_ARM_LDC_SB_G1: S + A - B(S)
3812   // R_ARM_LDC_SB_G2: S + A - B(S)
3813   static inline typename This::Status
3814   arm_grp_ldc(unsigned char* view,
3815       const Sized_relobj_file<32, big_endian>* object,
3816       const Symbol_value<32>* psymval,
3817       const int group,
3818       Arm_address address)
3819   {
3820     gold_assert(group >= 0 && group < 3);
3821     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3822     Valtype* wv = reinterpret_cast<Valtype*>(view);
3823     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3824
3825     const int sign = (insn & 0x00800000) ? 1 : -1;
3826     int32_t addend = ((insn & 0xff) << 2) * sign;
3827     int32_t x = (psymval->value(object, addend) - address);
3828     // Calculate the relevant G(n-1) value to obtain this stage residual.
3829     Valtype residual =
3830       Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3831     if ((residual & 0x3) != 0 || residual >= 0x400)
3832       return This::STATUS_OVERFLOW;
3833
3834     // Mask out the value and U bit.
3835     insn &= 0xff7fff00;
3836     // Set the U bit for non-negative values.
3837     if (x >= 0)
3838       insn |= 0x00800000;
3839     insn |= (residual >> 2);
3840
3841     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3842     return This::STATUS_OKAY;
3843   }
3844 };
3845
3846 // Relocate ARM long branches.  This handles relocation types
3847 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3848 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3849 // undefined and we do not use PLT in this relocation.  In such a case,
3850 // the branch is converted into an NOP.
3851
3852 template<bool big_endian>
3853 typename Arm_relocate_functions<big_endian>::Status
3854 Arm_relocate_functions<big_endian>::arm_branch_common(
3855     unsigned int r_type,
3856     const Relocate_info<32, big_endian>* relinfo,
3857     unsigned char* view,
3858     const Sized_symbol<32>* gsym,
3859     const Arm_relobj<big_endian>* object,
3860     unsigned int r_sym,
3861     const Symbol_value<32>* psymval,
3862     Arm_address address,
3863     Arm_address thumb_bit,
3864     bool is_weakly_undefined_without_plt)
3865 {
3866   typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3867   Valtype* wv = reinterpret_cast<Valtype*>(view);
3868   Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3869
3870   bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3871                     && ((val & 0x0f000000UL) == 0x0a000000UL);
3872   bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3873   bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3874                           && ((val & 0x0f000000UL) == 0x0b000000UL);
3875   bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3876   bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3877
3878   // Check that the instruction is valid.
3879   if (r_type == elfcpp::R_ARM_CALL)
3880     {
3881       if (!insn_is_uncond_bl && !insn_is_blx)
3882         return This::STATUS_BAD_RELOC;
3883     }
3884   else if (r_type == elfcpp::R_ARM_JUMP24)
3885     {
3886       if (!insn_is_b && !insn_is_cond_bl)
3887         return This::STATUS_BAD_RELOC;
3888     }
3889   else if (r_type == elfcpp::R_ARM_PLT32)
3890     {
3891       if (!insn_is_any_branch)
3892         return This::STATUS_BAD_RELOC;
3893     }
3894   else if (r_type == elfcpp::R_ARM_XPC25)
3895     {
3896       // FIXME: AAELF document IH0044C does not say much about it other
3897       // than it being obsolete.
3898       if (!insn_is_any_branch)
3899         return This::STATUS_BAD_RELOC;
3900     }
3901   else
3902     gold_unreachable();
3903
3904   // A branch to an undefined weak symbol is turned into a jump to
3905   // the next instruction unless a PLT entry will be created.
3906   // Do the same for local undefined symbols.
3907   // The jump to the next instruction is optimized as a NOP depending
3908   // on the architecture.
3909   const Target_arm<big_endian>* arm_target =
3910     Target_arm<big_endian>::default_target();
3911   if (is_weakly_undefined_without_plt)
3912     {
3913       gold_assert(!parameters->options().relocatable());
3914       Valtype cond = val & 0xf0000000U;
3915       if (arm_target->may_use_arm_nop())
3916         val = cond | 0x0320f000;
3917       else
3918         val = cond | 0x01a00000;        // Using pre-UAL nop: mov r0, r0.
3919       elfcpp::Swap<32, big_endian>::writeval(wv, val);
3920       return This::STATUS_OKAY;
3921     }
3922
3923   Valtype addend = Bits<26>::sign_extend32(val << 2);
3924   Valtype branch_target = psymval->value(object, addend);
3925   int32_t branch_offset = branch_target - address;
3926
3927   // We need a stub if the branch offset is too large or if we need
3928   // to switch mode.
3929   bool may_use_blx = arm_target->may_use_v5t_interworking();
3930   Reloc_stub* stub = NULL;
3931
3932   if (!parameters->options().relocatable()
3933       && (Bits<26>::has_overflow32(branch_offset)
3934           || ((thumb_bit != 0)
3935               && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3936     {
3937       Valtype unadjusted_branch_target = psymval->value(object, 0);
3938
3939       Stub_type stub_type =
3940         Reloc_stub::stub_type_for_reloc(r_type, address,
3941                                         unadjusted_branch_target,
3942                                         (thumb_bit != 0));
3943       if (stub_type != arm_stub_none)
3944         {
3945           Stub_table<big_endian>* stub_table =
3946             object->stub_table(relinfo->data_shndx);
3947           gold_assert(stub_table != NULL);
3948
3949           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3950           stub = stub_table->find_reloc_stub(stub_key);
3951           gold_assert(stub != NULL);
3952           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3953           branch_target = stub_table->address() + stub->offset() + addend;
3954           branch_offset = branch_target - address;
3955           gold_assert(!Bits<26>::has_overflow32(branch_offset));
3956         }
3957     }
3958
3959   // At this point, if we still need to switch mode, the instruction
3960   // must either be a BLX or a BL that can be converted to a BLX.
3961   if (thumb_bit != 0)
3962     {
3963       // Turn BL to BLX.
3964       gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3965       val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3966     }
3967
3968   val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL);
3969   elfcpp::Swap<32, big_endian>::writeval(wv, val);
3970   return (Bits<26>::has_overflow32(branch_offset)
3971           ? This::STATUS_OVERFLOW
3972           : This::STATUS_OKAY);
3973 }
3974
3975 // Relocate THUMB long branches.  This handles relocation types
3976 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3977 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3978 // undefined and we do not use PLT in this relocation.  In such a case,
3979 // the branch is converted into an NOP.
3980
3981 template<bool big_endian>
3982 typename Arm_relocate_functions<big_endian>::Status
3983 Arm_relocate_functions<big_endian>::thumb_branch_common(
3984     unsigned int r_type,
3985     const Relocate_info<32, big_endian>* relinfo,
3986     unsigned char* view,
3987     const Sized_symbol<32>* gsym,
3988     const Arm_relobj<big_endian>* object,
3989     unsigned int r_sym,
3990     const Symbol_value<32>* psymval,
3991     Arm_address address,
3992     Arm_address thumb_bit,
3993     bool is_weakly_undefined_without_plt)
3994 {
3995   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3996   Valtype* wv = reinterpret_cast<Valtype*>(view);
3997   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
3998   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
3999
4000   // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
4001   // into account.
4002   bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
4003   bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
4004
4005   // Check that the instruction is valid.
4006   if (r_type == elfcpp::R_ARM_THM_CALL)
4007     {
4008       if (!is_bl_insn && !is_blx_insn)
4009         return This::STATUS_BAD_RELOC;
4010     }
4011   else if (r_type == elfcpp::R_ARM_THM_JUMP24)
4012     {
4013       // This cannot be a BLX.
4014       if (!is_bl_insn)
4015         return This::STATUS_BAD_RELOC;
4016     }
4017   else if (r_type == elfcpp::R_ARM_THM_XPC22)
4018     {
4019       // Check for Thumb to Thumb call.
4020       if (!is_blx_insn)
4021         return This::STATUS_BAD_RELOC;
4022       if (thumb_bit != 0)
4023         {
4024           gold_warning(_("%s: Thumb BLX instruction targets "
4025                          "thumb function '%s'."),
4026                          object->name().c_str(),
4027                          (gsym ? gsym->name() : "(local)"));
4028           // Convert BLX to BL.
4029           lower_insn |= 0x1000U;
4030         }
4031     }
4032   else
4033     gold_unreachable();
4034
4035   // A branch to an undefined weak symbol is turned into a jump to
4036   // the next instruction unless a PLT entry will be created.
4037   // The jump to the next instruction is optimized as a NOP.W for
4038   // Thumb-2 enabled architectures.
4039   const Target_arm<big_endian>* arm_target =
4040     Target_arm<big_endian>::default_target();
4041   if (is_weakly_undefined_without_plt)
4042     {
4043       gold_assert(!parameters->options().relocatable());
4044       if (arm_target->may_use_thumb2_nop())
4045         {
4046           elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4047           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4048         }
4049       else
4050         {
4051           elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4052           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4053         }
4054       return This::STATUS_OKAY;
4055     }
4056
4057   int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4058   Arm_address branch_target = psymval->value(object, addend);
4059
4060   // For BLX, bit 1 of target address comes from bit 1 of base address.
4061   bool may_use_blx = arm_target->may_use_v5t_interworking();
4062   if (thumb_bit == 0 && may_use_blx)
4063     branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4064
4065   int32_t branch_offset = branch_target - address;
4066
4067   // We need a stub if the branch offset is too large or if we need
4068   // to switch mode.
4069   bool thumb2 = arm_target->using_thumb2();
4070   if (!parameters->options().relocatable()
4071       && ((!thumb2 && Bits<23>::has_overflow32(branch_offset))
4072           || (thumb2 && Bits<25>::has_overflow32(branch_offset))
4073           || ((thumb_bit == 0)
4074               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4075                   || r_type == elfcpp::R_ARM_THM_JUMP24))))
4076     {
4077       Arm_address unadjusted_branch_target = psymval->value(object, 0);
4078
4079       Stub_type stub_type =
4080         Reloc_stub::stub_type_for_reloc(r_type, address,
4081                                         unadjusted_branch_target,
4082                                         (thumb_bit != 0));
4083
4084       if (stub_type != arm_stub_none)
4085         {
4086           Stub_table<big_endian>* stub_table =
4087             object->stub_table(relinfo->data_shndx);
4088           gold_assert(stub_table != NULL);
4089
4090           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4091           Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4092           gold_assert(stub != NULL);
4093           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4094           branch_target = stub_table->address() + stub->offset() + addend;
4095           if (thumb_bit == 0 && may_use_blx)
4096             branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4097           branch_offset = branch_target - address;
4098         }
4099     }
4100
4101   // At this point, if we still need to switch mode, the instruction
4102   // must either be a BLX or a BL that can be converted to a BLX.
4103   if (thumb_bit == 0)
4104     {
4105       gold_assert(may_use_blx
4106                   && (r_type == elfcpp::R_ARM_THM_CALL
4107                       || r_type == elfcpp::R_ARM_THM_XPC22));
4108       // Make sure this is a BLX.
4109       lower_insn &= ~0x1000U;
4110     }
4111   else
4112     {
4113       // Make sure this is a BL.
4114       lower_insn |= 0x1000U;
4115     }
4116
4117   // For a BLX instruction, make sure that the relocation is rounded up
4118   // to a word boundary.  This follows the semantics of the instruction
4119   // which specifies that bit 1 of the target address will come from bit
4120   // 1 of the base address.
4121   if ((lower_insn & 0x5000U) == 0x4000U)
4122     gold_assert((branch_offset & 3) == 0);
4123
4124   // Put BRANCH_OFFSET back into the insn.  Assumes two's complement.
4125   // We use the Thumb-2 encoding, which is safe even if dealing with
4126   // a Thumb-1 instruction by virtue of our overflow check above.  */
4127   upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4128   lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4129
4130   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4131   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4132
4133   gold_assert(!Bits<25>::has_overflow32(branch_offset));
4134
4135   return ((thumb2
4136            ? Bits<25>::has_overflow32(branch_offset)
4137            : Bits<23>::has_overflow32(branch_offset))
4138           ? This::STATUS_OVERFLOW
4139           : This::STATUS_OKAY);
4140 }
4141
4142 // Relocate THUMB-2 long conditional branches.
4143 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
4144 // undefined and we do not use PLT in this relocation.  In such a case,
4145 // the branch is converted into an NOP.
4146
4147 template<bool big_endian>
4148 typename Arm_relocate_functions<big_endian>::Status
4149 Arm_relocate_functions<big_endian>::thm_jump19(
4150     unsigned char* view,
4151     const Arm_relobj<big_endian>* object,
4152     const Symbol_value<32>* psymval,
4153     Arm_address address,
4154     Arm_address thumb_bit)
4155 {
4156   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4157   Valtype* wv = reinterpret_cast<Valtype*>(view);
4158   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4159   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4160   int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4161
4162   Arm_address branch_target = psymval->value(object, addend);
4163   int32_t branch_offset = branch_target - address;
4164
4165   // ??? Should handle interworking?  GCC might someday try to
4166   // use this for tail calls.
4167   // FIXME: We do support thumb entry to PLT yet.
4168   if (thumb_bit == 0)
4169     {
4170       gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4171       return This::STATUS_BAD_RELOC;
4172     }
4173
4174   // Put RELOCATION back into the insn.
4175   upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4176   lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4177
4178   // Put the relocated value back in the object file:
4179   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4180   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4181
4182   return (Bits<21>::has_overflow32(branch_offset)
4183           ? This::STATUS_OVERFLOW
4184           : This::STATUS_OKAY);
4185 }
4186
4187 // Get the GOT section, creating it if necessary.
4188
4189 template<bool big_endian>
4190 Arm_output_data_got<big_endian>*
4191 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4192 {
4193   if (this->got_ == NULL)
4194     {
4195       gold_assert(symtab != NULL && layout != NULL);
4196
4197       // When using -z now, we can treat .got as a relro section.
4198       // Without -z now, it is modified after program startup by lazy
4199       // PLT relocations.
4200       bool is_got_relro = parameters->options().now();
4201       Output_section_order got_order = (is_got_relro
4202                                         ? ORDER_RELRO_LAST
4203                                         : ORDER_DATA);
4204
4205       // Unlike some targets (.e.g x86), ARM does not use separate .got and
4206       // .got.plt sections in output.  The output .got section contains both
4207       // PLT and non-PLT GOT entries.
4208       this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4209
4210       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4211                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4212                                       this->got_, got_order, is_got_relro);
4213
4214       // The old GNU linker creates a .got.plt section.  We just
4215       // create another set of data in the .got section.  Note that we
4216       // always create a PLT if we create a GOT, although the PLT
4217       // might be empty.
4218       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4219       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4220                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4221                                       this->got_plt_, got_order, is_got_relro);
4222
4223       // The first three entries are reserved.
4224       this->got_plt_->set_current_data_size(3 * 4);
4225
4226       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4227       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4228                                     Symbol_table::PREDEFINED,
4229                                     this->got_plt_,
4230                                     0, 0, elfcpp::STT_OBJECT,
4231                                     elfcpp::STB_LOCAL,
4232                                     elfcpp::STV_HIDDEN, 0,
4233                                     false, false);
4234     }
4235   return this->got_;
4236 }
4237
4238 // Get the dynamic reloc section, creating it if necessary.
4239
4240 template<bool big_endian>
4241 typename Target_arm<big_endian>::Reloc_section*
4242 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4243 {
4244   if (this->rel_dyn_ == NULL)
4245     {
4246       gold_assert(layout != NULL);
4247       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4248       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4249                                       elfcpp::SHF_ALLOC, this->rel_dyn_,
4250                                       ORDER_DYNAMIC_RELOCS, false);
4251     }
4252   return this->rel_dyn_;
4253 }
4254
4255 // Insn_template methods.
4256
4257 // Return byte size of an instruction template.
4258
4259 size_t
4260 Insn_template::size() const
4261 {
4262   switch (this->type())
4263     {
4264     case THUMB16_TYPE:
4265     case THUMB16_SPECIAL_TYPE:
4266       return 2;
4267     case ARM_TYPE:
4268     case THUMB32_TYPE:
4269     case DATA_TYPE:
4270       return 4;
4271     default:
4272       gold_unreachable();
4273     }
4274 }
4275
4276 // Return alignment of an instruction template.
4277
4278 unsigned
4279 Insn_template::alignment() const
4280 {
4281   switch (this->type())
4282     {
4283     case THUMB16_TYPE:
4284     case THUMB16_SPECIAL_TYPE:
4285     case THUMB32_TYPE:
4286       return 2;
4287     case ARM_TYPE:
4288     case DATA_TYPE:
4289       return 4;
4290     default:
4291       gold_unreachable();
4292     }
4293 }
4294
4295 // Stub_template methods.
4296
4297 Stub_template::Stub_template(
4298     Stub_type type, const Insn_template* insns,
4299      size_t insn_count)
4300   : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4301     entry_in_thumb_mode_(false), relocs_()
4302 {
4303   off_t offset = 0;
4304
4305   // Compute byte size and alignment of stub template.
4306   for (size_t i = 0; i < insn_count; i++)
4307     {
4308       unsigned insn_alignment = insns[i].alignment();
4309       size_t insn_size = insns[i].size();
4310       gold_assert((offset & (insn_alignment - 1)) == 0);
4311       this->alignment_ = std::max(this->alignment_, insn_alignment);
4312       switch (insns[i].type())
4313         {
4314         case Insn_template::THUMB16_TYPE:
4315         case Insn_template::THUMB16_SPECIAL_TYPE:
4316           if (i == 0)
4317             this->entry_in_thumb_mode_ = true;
4318           break;
4319
4320         case Insn_template::THUMB32_TYPE:
4321           if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4322             this->relocs_.push_back(Reloc(i, offset));
4323           if (i == 0)
4324             this->entry_in_thumb_mode_ = true;
4325           break;
4326
4327         case Insn_template::ARM_TYPE:
4328           // Handle cases where the target is encoded within the
4329           // instruction.
4330           if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4331             this->relocs_.push_back(Reloc(i, offset));
4332           break;
4333
4334         case Insn_template::DATA_TYPE:
4335           // Entry point cannot be data.
4336           gold_assert(i != 0);
4337           this->relocs_.push_back(Reloc(i, offset));
4338           break;
4339
4340         default:
4341           gold_unreachable();
4342         }
4343       offset += insn_size;
4344     }
4345   this->size_ = offset;
4346 }
4347
4348 // Stub methods.
4349
4350 // Template to implement do_write for a specific target endianness.
4351
4352 template<bool big_endian>
4353 void inline
4354 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4355 {
4356   const Stub_template* stub_template = this->stub_template();
4357   const Insn_template* insns = stub_template->insns();
4358
4359   // FIXME:  We do not handle BE8 encoding yet.
4360   unsigned char* pov = view;
4361   for (size_t i = 0; i < stub_template->insn_count(); i++)
4362     {
4363       switch (insns[i].type())
4364         {
4365         case Insn_template::THUMB16_TYPE:
4366           elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4367           break;
4368         case Insn_template::THUMB16_SPECIAL_TYPE:
4369           elfcpp::Swap<16, big_endian>::writeval(
4370               pov,
4371               this->thumb16_special(i));
4372           break;
4373         case Insn_template::THUMB32_TYPE:
4374           {
4375             uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4376             uint32_t lo = insns[i].data() & 0xffff;
4377             elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4378             elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4379           }
4380           break;
4381         case Insn_template::ARM_TYPE:
4382         case Insn_template::DATA_TYPE:
4383           elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4384           break;
4385         default:
4386           gold_unreachable();
4387         }
4388       pov += insns[i].size();
4389     }
4390   gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4391 }
4392
4393 // Reloc_stub::Key methods.
4394
4395 // Dump a Key as a string for debugging.
4396
4397 std::string
4398 Reloc_stub::Key::name() const
4399 {
4400   if (this->r_sym_ == invalid_index)
4401     {
4402       // Global symbol key name
4403       // <stub-type>:<symbol name>:<addend>.
4404       const std::string sym_name = this->u_.symbol->name();
4405       // We need to print two hex number and two colons.  So just add 100 bytes
4406       // to the symbol name size.
4407       size_t len = sym_name.size() + 100;
4408       char* buffer = new char[len];
4409       int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4410                        sym_name.c_str(), this->addend_);
4411       gold_assert(c > 0 && c < static_cast<int>(len));
4412       delete[] buffer;
4413       return std::string(buffer);
4414     }
4415   else
4416     {
4417       // local symbol key name
4418       // <stub-type>:<object>:<r_sym>:<addend>.
4419       const size_t len = 200;
4420       char buffer[len];
4421       int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4422                        this->u_.relobj, this->r_sym_, this->addend_);
4423       gold_assert(c > 0 && c < static_cast<int>(len));
4424       return std::string(buffer);
4425     }
4426 }
4427
4428 // Reloc_stub methods.
4429
4430 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4431 // LOCATION to DESTINATION.
4432 // This code is based on the arm_type_of_stub function in
4433 // bfd/elf32-arm.c.  We have changed the interface a little to keep the Stub
4434 // class simple.
4435
4436 Stub_type
4437 Reloc_stub::stub_type_for_reloc(
4438    unsigned int r_type,
4439    Arm_address location,
4440    Arm_address destination,
4441    bool target_is_thumb)
4442 {
4443   Stub_type stub_type = arm_stub_none;
4444
4445   // This is a bit ugly but we want to avoid using a templated class for
4446   // big and little endianities.
4447   bool may_use_blx;
4448   bool should_force_pic_veneer;
4449   bool thumb2;
4450   bool thumb_only;
4451   if (parameters->target().is_big_endian())
4452     {
4453       const Target_arm<true>* big_endian_target =
4454         Target_arm<true>::default_target();
4455       may_use_blx = big_endian_target->may_use_v5t_interworking();
4456       should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4457       thumb2 = big_endian_target->using_thumb2();
4458       thumb_only = big_endian_target->using_thumb_only();
4459     }
4460   else
4461     {
4462       const Target_arm<false>* little_endian_target =
4463         Target_arm<false>::default_target();
4464       may_use_blx = little_endian_target->may_use_v5t_interworking();
4465       should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4466       thumb2 = little_endian_target->using_thumb2();
4467       thumb_only = little_endian_target->using_thumb_only();
4468     }
4469
4470   int64_t branch_offset;
4471   bool output_is_position_independent =
4472       parameters->options().output_is_position_independent();
4473   if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4474     {
4475       // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4476       // base address (instruction address + 4).
4477       if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4478         destination = Bits<32>::bit_select32(destination, location, 0x2);
4479       branch_offset = static_cast<int64_t>(destination) - location;
4480
4481       // Handle cases where:
4482       // - this call goes too far (different Thumb/Thumb2 max
4483       //   distance)
4484       // - it's a Thumb->Arm call and blx is not available, or it's a
4485       //   Thumb->Arm branch (not bl). A stub is needed in this case.
4486       if ((!thumb2
4487             && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4488                 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4489           || (thumb2
4490               && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4491                   || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4492           || ((!target_is_thumb)
4493               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4494                   || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4495         {
4496           if (target_is_thumb)
4497             {
4498               // Thumb to thumb.
4499               if (!thumb_only)
4500                 {
4501                   stub_type = (output_is_position_independent
4502                                || should_force_pic_veneer)
4503                     // PIC stubs.
4504                     ? ((may_use_blx
4505                         && (r_type == elfcpp::R_ARM_THM_CALL))
4506                        // V5T and above. Stub starts with ARM code, so
4507                        // we must be able to switch mode before
4508                        // reaching it, which is only possible for 'bl'
4509                        // (ie R_ARM_THM_CALL relocation).
4510                        ? arm_stub_long_branch_any_thumb_pic
4511                        // On V4T, use Thumb code only.
4512                        : arm_stub_long_branch_v4t_thumb_thumb_pic)
4513
4514                     // non-PIC stubs.
4515                     : ((may_use_blx
4516                         && (r_type == elfcpp::R_ARM_THM_CALL))
4517                        ? arm_stub_long_branch_any_any // V5T and above.
4518                        : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4519                 }
4520               else
4521                 {
4522                   stub_type = (output_is_position_independent
4523                                || should_force_pic_veneer)
4524                     ? arm_stub_long_branch_thumb_only_pic       // PIC stub.
4525                     : arm_stub_long_branch_thumb_only;  // non-PIC stub.
4526                 }
4527             }
4528           else
4529             {
4530               // Thumb to arm.
4531
4532               // FIXME: We should check that the input section is from an
4533               // object that has interwork enabled.
4534
4535               stub_type = (output_is_position_independent
4536                            || should_force_pic_veneer)
4537                 // PIC stubs.
4538                 ? ((may_use_blx
4539                     && (r_type == elfcpp::R_ARM_THM_CALL))
4540                    ? arm_stub_long_branch_any_arm_pic   // V5T and above.
4541                    : arm_stub_long_branch_v4t_thumb_arm_pic)    // V4T.
4542
4543                 // non-PIC stubs.
4544                 : ((may_use_blx
4545                     && (r_type == elfcpp::R_ARM_THM_CALL))
4546                    ? arm_stub_long_branch_any_any       // V5T and above.
4547                    : arm_stub_long_branch_v4t_thumb_arm);       // V4T.
4548
4549               // Handle v4t short branches.
4550               if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4551                   && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4552                   && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4553                 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4554             }
4555         }
4556     }
4557   else if (r_type == elfcpp::R_ARM_CALL
4558            || r_type == elfcpp::R_ARM_JUMP24
4559            || r_type == elfcpp::R_ARM_PLT32)
4560     {
4561       branch_offset = static_cast<int64_t>(destination) - location;
4562       if (target_is_thumb)
4563         {
4564           // Arm to thumb.
4565
4566           // FIXME: We should check that the input section is from an
4567           // object that has interwork enabled.
4568
4569           // We have an extra 2-bytes reach because of
4570           // the mode change (bit 24 (H) of BLX encoding).
4571           if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4572               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4573               || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4574               || (r_type == elfcpp::R_ARM_JUMP24)
4575               || (r_type == elfcpp::R_ARM_PLT32))
4576             {
4577               stub_type = (output_is_position_independent
4578                            || should_force_pic_veneer)
4579                 // PIC stubs.
4580                 ? (may_use_blx
4581                    ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4582                    : arm_stub_long_branch_v4t_arm_thumb_pic)    // V4T stub.
4583
4584                 // non-PIC stubs.
4585                 : (may_use_blx
4586                    ? arm_stub_long_branch_any_any       // V5T and above.
4587                    : arm_stub_long_branch_v4t_arm_thumb);       // V4T.
4588             }
4589         }
4590       else
4591         {
4592           // Arm to arm.
4593           if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4594               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4595             {
4596               stub_type = (output_is_position_independent
4597                            || should_force_pic_veneer)
4598                 ? arm_stub_long_branch_any_arm_pic      // PIC stubs.
4599                 : arm_stub_long_branch_any_any;         /// non-PIC.
4600             }
4601         }
4602     }
4603
4604   return stub_type;
4605 }
4606
4607 // Cortex_a8_stub methods.
4608
4609 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4610 // I is the position of the instruction template in the stub template.
4611
4612 uint16_t
4613 Cortex_a8_stub::do_thumb16_special(size_t i)
4614 {
4615   // The only use of this is to copy condition code from a conditional
4616   // branch being worked around to the corresponding conditional branch in
4617   // to the stub.
4618   gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4619               && i == 0);
4620   uint16_t data = this->stub_template()->insns()[i].data();
4621   gold_assert((data & 0xff00U) == 0xd000U);
4622   data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4623   return data;
4624 }
4625
4626 // Stub_factory methods.
4627
4628 Stub_factory::Stub_factory()
4629 {
4630   // The instruction template sequences are declared as static
4631   // objects and initialized first time the constructor runs.
4632
4633   // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4634   // to reach the stub if necessary.
4635   static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4636     {
4637       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4638       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4639                                                 // dcd   R_ARM_ABS32(X)
4640     };
4641
4642   // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4643   // available.
4644   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4645     {
4646       Insn_template::arm_insn(0xe59fc000),      // ldr   ip, [pc, #0]
4647       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4648       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4649                                                 // dcd   R_ARM_ABS32(X)
4650     };
4651
4652   // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4653   static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4654     {
4655       Insn_template::thumb16_insn(0xb401),      // push {r0}
4656       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4657       Insn_template::thumb16_insn(0x4684),      // mov  ip, r0
4658       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4659       Insn_template::thumb16_insn(0x4760),      // bx   ip
4660       Insn_template::thumb16_insn(0xbf00),      // nop
4661       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4662                                                 // dcd  R_ARM_ABS32(X)
4663     };
4664
4665   // V4T Thumb -> Thumb long branch stub. Using the stack is not
4666   // allowed.
4667   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4668     {
4669       Insn_template::thumb16_insn(0x4778),      // bx   pc
4670       Insn_template::thumb16_insn(0x46c0),      // nop
4671       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4672       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4673       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4674                                                 // dcd  R_ARM_ABS32(X)
4675     };
4676
4677   // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4678   // available.
4679   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4680     {
4681       Insn_template::thumb16_insn(0x4778),      // bx   pc
4682       Insn_template::thumb16_insn(0x46c0),      // nop
4683       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4684       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4685                                                 // dcd   R_ARM_ABS32(X)
4686     };
4687
4688   // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4689   // one, when the destination is close enough.
4690   static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4691     {
4692       Insn_template::thumb16_insn(0x4778),              // bx   pc
4693       Insn_template::thumb16_insn(0x46c0),              // nop
4694       Insn_template::arm_rel_insn(0xea000000, -8),      // b    (X-8)
4695     };
4696
4697   // ARM/Thumb -> ARM long branch stub, PIC.  On V5T and above, use
4698   // blx to reach the stub if necessary.
4699   static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4700     {
4701       Insn_template::arm_insn(0xe59fc000),      // ldr   r12, [pc]
4702       Insn_template::arm_insn(0xe08ff00c),      // add   pc, pc, ip
4703       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4704                                                 // dcd   R_ARM_REL32(X-4)
4705     };
4706
4707   // ARM/Thumb -> Thumb long branch stub, PIC.  On V5T and above, use
4708   // blx to reach the stub if necessary.  We can not add into pc;
4709   // it is not guaranteed to mode switch (different in ARMv6 and
4710   // ARMv7).
4711   static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4712     {
4713       Insn_template::arm_insn(0xe59fc004),      // ldr   r12, [pc, #4]
4714       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4715       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4716       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4717                                                 // dcd   R_ARM_REL32(X)
4718     };
4719
4720   // V4T ARM -> ARM long branch stub, PIC.
4721   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4722     {
4723       Insn_template::arm_insn(0xe59fc004),      // ldr   ip, [pc, #4]
4724       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4725       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4726       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4727                                                 // dcd   R_ARM_REL32(X)
4728     };
4729
4730   // V4T Thumb -> ARM long branch stub, PIC.
4731   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4732     {
4733       Insn_template::thumb16_insn(0x4778),      // bx   pc
4734       Insn_template::thumb16_insn(0x46c0),      // nop
4735       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4736       Insn_template::arm_insn(0xe08cf00f),      // add  pc, ip, pc
4737       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4738                                                 // dcd  R_ARM_REL32(X)
4739     };
4740
4741   // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4742   // architectures.
4743   static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4744     {
4745       Insn_template::thumb16_insn(0xb401),      // push {r0}
4746       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4747       Insn_template::thumb16_insn(0x46fc),      // mov  ip, pc
4748       Insn_template::thumb16_insn(0x4484),      // add  ip, r0
4749       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4750       Insn_template::thumb16_insn(0x4760),      // bx   ip
4751       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4752                                                 // dcd  R_ARM_REL32(X)
4753     };
4754
4755   // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4756   // allowed.
4757   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4758     {
4759       Insn_template::thumb16_insn(0x4778),      // bx   pc
4760       Insn_template::thumb16_insn(0x46c0),      // nop
4761       Insn_template::arm_insn(0xe59fc004),      // ldr  ip, [pc, #4]
4762       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4763       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4764       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4765                                                 // dcd  R_ARM_REL32(X)
4766     };
4767
4768   // Cortex-A8 erratum-workaround stubs.
4769
4770   // Stub used for conditional branches (which may be beyond +/-1MB away,
4771   // so we can't use a conditional branch to reach this stub).
4772
4773   // original code:
4774   //
4775   //    b<cond> X
4776   // after:
4777   //
4778   static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4779     {
4780       Insn_template::thumb16_bcond_insn(0xd001),        //      b<cond>.n true
4781       Insn_template::thumb32_b_insn(0xf000b800, -4),    //      b.w after
4782       Insn_template::thumb32_b_insn(0xf000b800, -4)     // true:
4783                                                         //      b.w X
4784     };
4785
4786   // Stub used for b.w and bl.w instructions.
4787
4788   static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4789     {
4790       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4791     };
4792
4793   static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4794     {
4795       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4796     };
4797
4798   // Stub used for Thumb-2 blx.w instructions.  We modified the original blx.w
4799   // instruction (which switches to ARM mode) to point to this stub.  Jump to
4800   // the real destination using an ARM-mode branch.
4801   static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4802     {
4803       Insn_template::arm_rel_insn(0xea000000, -8)       // b dest
4804     };
4805
4806   // Stub used to provide an interworking for R_ARM_V4BX relocation
4807   // (bx r[n] instruction).
4808   static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4809     {
4810       Insn_template::arm_insn(0xe3100001),              // tst   r<n>, #1
4811       Insn_template::arm_insn(0x01a0f000),              // moveq pc, r<n>
4812       Insn_template::arm_insn(0xe12fff10)               // bx    r<n>
4813     };
4814
4815   // Fill in the stub template look-up table.  Stub templates are constructed
4816   // per instance of Stub_factory for fast look-up without locking
4817   // in a thread-enabled environment.
4818
4819   this->stub_templates_[arm_stub_none] =
4820     new Stub_template(arm_stub_none, NULL, 0);
4821
4822 #define DEF_STUB(x)     \
4823   do \
4824     { \
4825       size_t array_size \
4826         = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4827       Stub_type type = arm_stub_##x; \
4828       this->stub_templates_[type] = \
4829         new Stub_template(type, elf32_arm_stub_##x, array_size); \
4830     } \
4831   while (0);
4832
4833   DEF_STUBS
4834 #undef DEF_STUB
4835 }
4836
4837 // Stub_table methods.
4838
4839 // Remove all Cortex-A8 stub.
4840
4841 template<bool big_endian>
4842 void
4843 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4844 {
4845   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4846        p != this->cortex_a8_stubs_.end();
4847        ++p)
4848     delete p->second;
4849   this->cortex_a8_stubs_.clear();
4850 }
4851
4852 // Relocate one stub.  This is a helper for Stub_table::relocate_stubs().
4853
4854 template<bool big_endian>
4855 void
4856 Stub_table<big_endian>::relocate_stub(
4857     Stub* stub,
4858     const Relocate_info<32, big_endian>* relinfo,
4859     Target_arm<big_endian>* arm_target,
4860     Output_section* output_section,
4861     unsigned char* view,
4862     Arm_address address,
4863     section_size_type view_size)
4864 {
4865   const Stub_template* stub_template = stub->stub_template();
4866   if (stub_template->reloc_count() != 0)
4867     {
4868       // Adjust view to cover the stub only.
4869       section_size_type offset = stub->offset();
4870       section_size_type stub_size = stub_template->size();
4871       gold_assert(offset + stub_size <= view_size);
4872
4873       arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4874                                 address + offset, stub_size);
4875     }
4876 }
4877
4878 // Relocate all stubs in this stub table.
4879
4880 template<bool big_endian>
4881 void
4882 Stub_table<big_endian>::relocate_stubs(
4883     const Relocate_info<32, big_endian>* relinfo,
4884     Target_arm<big_endian>* arm_target,
4885     Output_section* output_section,
4886     unsigned char* view,
4887     Arm_address address,
4888     section_size_type view_size)
4889 {
4890   // If we are passed a view bigger than the stub table's.  we need to
4891   // adjust the view.
4892   gold_assert(address == this->address()
4893               && (view_size
4894                   == static_cast<section_size_type>(this->data_size())));
4895
4896   // Relocate all relocation stubs.
4897   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4898       p != this->reloc_stubs_.end();
4899       ++p)
4900     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4901                         address, view_size);
4902
4903   // Relocate all Cortex-A8 stubs.
4904   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4905        p != this->cortex_a8_stubs_.end();
4906        ++p)
4907     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4908                         address, view_size);
4909
4910   // Relocate all ARM V4BX stubs.
4911   for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4912        p != this->arm_v4bx_stubs_.end();
4913        ++p)
4914     {
4915       if (*p != NULL)
4916         this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4917                             address, view_size);
4918     }
4919 }
4920
4921 // Write out the stubs to file.
4922
4923 template<bool big_endian>
4924 void
4925 Stub_table<big_endian>::do_write(Output_file* of)
4926 {
4927   off_t offset = this->offset();
4928   const section_size_type oview_size =
4929     convert_to_section_size_type(this->data_size());
4930   unsigned char* const oview = of->get_output_view(offset, oview_size);
4931
4932   // Write relocation stubs.
4933   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4934       p != this->reloc_stubs_.end();
4935       ++p)
4936     {
4937       Reloc_stub* stub = p->second;
4938       Arm_address address = this->address() + stub->offset();
4939       gold_assert(address
4940                   == align_address(address,
4941                                    stub->stub_template()->alignment()));
4942       stub->write(oview + stub->offset(), stub->stub_template()->size(),
4943                   big_endian);
4944     }
4945
4946   // Write Cortex-A8 stubs.
4947   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4948        p != this->cortex_a8_stubs_.end();
4949        ++p)
4950     {
4951       Cortex_a8_stub* stub = p->second;
4952       Arm_address address = this->address() + stub->offset();
4953       gold_assert(address
4954                   == align_address(address,
4955                                    stub->stub_template()->alignment()));
4956       stub->write(oview + stub->offset(), stub->stub_template()->size(),
4957                   big_endian);
4958     }
4959
4960   // Write ARM V4BX relocation stubs.
4961   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4962        p != this->arm_v4bx_stubs_.end();
4963        ++p)
4964     {
4965       if (*p == NULL)
4966         continue;
4967
4968       Arm_address address = this->address() + (*p)->offset();
4969       gold_assert(address
4970                   == align_address(address,
4971                                    (*p)->stub_template()->alignment()));
4972       (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4973                   big_endian);
4974     }
4975
4976   of->write_output_view(this->offset(), oview_size, oview);
4977 }
4978
4979 // Update the data size and address alignment of the stub table at the end
4980 // of a relaxation pass.   Return true if either the data size or the
4981 // alignment changed in this relaxation pass.
4982
4983 template<bool big_endian>
4984 bool
4985 Stub_table<big_endian>::update_data_size_and_addralign()
4986 {
4987   // Go over all stubs in table to compute data size and address alignment.
4988   off_t size = this->reloc_stubs_size_;
4989   unsigned addralign = this->reloc_stubs_addralign_;
4990
4991   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4992        p != this->cortex_a8_stubs_.end();
4993        ++p)
4994     {
4995       const Stub_template* stub_template = p->second->stub_template();
4996       addralign = std::max(addralign, stub_template->alignment());
4997       size = (align_address(size, stub_template->alignment())
4998               + stub_template->size());
4999     }
5000
5001   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5002        p != this->arm_v4bx_stubs_.end();
5003        ++p)
5004     {
5005       if (*p == NULL)
5006         continue;
5007
5008       const Stub_template* stub_template = (*p)->stub_template();
5009       addralign = std::max(addralign, stub_template->alignment());
5010       size = (align_address(size, stub_template->alignment())
5011               + stub_template->size());
5012     }
5013
5014   // Check if either data size or alignment changed in this pass.
5015   // Update prev_data_size_ and prev_addralign_.  These will be used
5016   // as the current data size and address alignment for the next pass.
5017   bool changed = size != this->prev_data_size_;
5018   this->prev_data_size_ = size;
5019
5020   if (addralign != this->prev_addralign_)
5021     changed = true;
5022   this->prev_addralign_ = addralign;
5023
5024   return changed;
5025 }
5026
5027 // Finalize the stubs.  This sets the offsets of the stubs within the stub
5028 // table.  It also marks all input sections needing Cortex-A8 workaround.
5029
5030 template<bool big_endian>
5031 void
5032 Stub_table<big_endian>::finalize_stubs()
5033 {
5034   off_t off = this->reloc_stubs_size_;
5035   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5036        p != this->cortex_a8_stubs_.end();
5037        ++p)
5038     {
5039       Cortex_a8_stub* stub = p->second;
5040       const Stub_template* stub_template = stub->stub_template();
5041       uint64_t stub_addralign = stub_template->alignment();
5042       off = align_address(off, stub_addralign);
5043       stub->set_offset(off);
5044       off += stub_template->size();
5045
5046       // Mark input section so that we can determine later if a code section
5047       // needs the Cortex-A8 workaround quickly.
5048       Arm_relobj<big_endian>* arm_relobj =
5049         Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5050       arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5051     }
5052
5053   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5054       p != this->arm_v4bx_stubs_.end();
5055       ++p)
5056     {
5057       if (*p == NULL)
5058         continue;
5059
5060       const Stub_template* stub_template = (*p)->stub_template();
5061       uint64_t stub_addralign = stub_template->alignment();
5062       off = align_address(off, stub_addralign);
5063       (*p)->set_offset(off);
5064       off += stub_template->size();
5065     }
5066
5067   gold_assert(off <= this->prev_data_size_);
5068 }
5069
5070 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5071 // and VIEW_ADDRESS + VIEW_SIZE - 1.  VIEW points to the mapped address
5072 // of the address range seen by the linker.
5073
5074 template<bool big_endian>
5075 void
5076 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5077     Target_arm<big_endian>* arm_target,
5078     unsigned char* view,
5079     Arm_address view_address,
5080     section_size_type view_size)
5081 {
5082   // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5083   for (Cortex_a8_stub_list::const_iterator p =
5084          this->cortex_a8_stubs_.lower_bound(view_address);
5085        ((p != this->cortex_a8_stubs_.end())
5086         && (p->first < (view_address + view_size)));
5087        ++p)
5088     {
5089       // We do not store the THUMB bit in the LSB of either the branch address
5090       // or the stub offset.  There is no need to strip the LSB.
5091       Arm_address branch_address = p->first;
5092       const Cortex_a8_stub* stub = p->second;
5093       Arm_address stub_address = this->address() + stub->offset();
5094
5095       // Offset of the branch instruction relative to this view.
5096       section_size_type offset =
5097         convert_to_section_size_type(branch_address - view_address);
5098       gold_assert((offset + 4) <= view_size);
5099
5100       arm_target->apply_cortex_a8_workaround(stub, stub_address,
5101                                              view + offset, branch_address);
5102     }
5103 }
5104
5105 // Arm_input_section methods.
5106
5107 // Initialize an Arm_input_section.
5108
5109 template<bool big_endian>
5110 void
5111 Arm_input_section<big_endian>::init()
5112 {
5113   Relobj* relobj = this->relobj();
5114   unsigned int shndx = this->shndx();
5115
5116   // We have to cache original size, alignment and contents to avoid locking
5117   // the original file.
5118   this->original_addralign_ =
5119     convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5120
5121   // This is not efficient but we expect only a small number of relaxed
5122   // input sections for stubs.
5123   section_size_type section_size;
5124   const unsigned char* section_contents =
5125     relobj->section_contents(shndx, &section_size, false);
5126   this->original_size_ =
5127     convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5128
5129   gold_assert(this->original_contents_ == NULL);
5130   this->original_contents_ = new unsigned char[section_size];
5131   memcpy(this->original_contents_, section_contents, section_size);
5132
5133   // We want to make this look like the original input section after
5134   // output sections are finalized.
5135   Output_section* os = relobj->output_section(shndx);
5136   off_t offset = relobj->output_section_offset(shndx);
5137   gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5138   this->set_address(os->address() + offset);
5139   this->set_file_offset(os->offset() + offset);
5140
5141   this->set_current_data_size(this->original_size_);
5142   this->finalize_data_size();
5143 }
5144
5145 template<bool big_endian>
5146 void
5147 Arm_input_section<big_endian>::do_write(Output_file* of)
5148 {
5149   // We have to write out the original section content.
5150   gold_assert(this->original_contents_ != NULL);
5151   of->write(this->offset(), this->original_contents_,
5152             this->original_size_);
5153
5154   // If this owns a stub table and it is not empty, write it.
5155   if (this->is_stub_table_owner() && !this->stub_table_->empty())
5156     this->stub_table_->write(of);
5157 }
5158
5159 // Finalize data size.
5160
5161 template<bool big_endian>
5162 void
5163 Arm_input_section<big_endian>::set_final_data_size()
5164 {
5165   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5166
5167   if (this->is_stub_table_owner())
5168     {
5169       this->stub_table_->finalize_data_size();
5170       off = align_address(off, this->stub_table_->addralign());
5171       off += this->stub_table_->data_size();
5172     }
5173   this->set_data_size(off);
5174 }
5175
5176 // Reset address and file offset.
5177
5178 template<bool big_endian>
5179 void
5180 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5181 {
5182   // Size of the original input section contents.
5183   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5184
5185   // If this is a stub table owner, account for the stub table size.
5186   if (this->is_stub_table_owner())
5187     {
5188       Stub_table<big_endian>* stub_table = this->stub_table_;
5189
5190       // Reset the stub table's address and file offset.  The
5191       // current data size for child will be updated after that.
5192       stub_table_->reset_address_and_file_offset();
5193       off = align_address(off, stub_table_->addralign());
5194       off += stub_table->current_data_size();
5195     }
5196
5197   this->set_current_data_size(off);
5198 }
5199
5200 // Arm_exidx_cantunwind methods.
5201
5202 // Write this to Output file OF for a fixed endianness.
5203
5204 template<bool big_endian>
5205 void
5206 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5207 {
5208   off_t offset = this->offset();
5209   const section_size_type oview_size = 8;
5210   unsigned char* const oview = of->get_output_view(offset, oview_size);
5211
5212   typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
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   // We only care about sections containing code.
5648   if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
5649     return;
5650
5651   // States for grouping.
5652   typedef enum
5653   {
5654     // No group is being built.
5655     NO_GROUP,
5656     // A group is being built but the stub table is not found yet.
5657     // We keep group a stub group until the size is just under GROUP_SIZE.
5658     // The last input section in the group will be used as the stub table.
5659     FINDING_STUB_SECTION,
5660     // A group is being built and we have already found a stub table.
5661     // We enter this state to grow a stub group by adding input section
5662     // after the stub table.  This effectively doubles the group size.
5663     HAS_STUB_SECTION
5664   } State;
5665
5666   // Any newly created relaxed sections are stored here.
5667   std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5668
5669   State state = NO_GROUP;
5670   section_size_type off = 0;
5671   section_size_type group_begin_offset = 0;
5672   section_size_type group_end_offset = 0;
5673   section_size_type stub_table_end_offset = 0;
5674   Input_section_list::const_iterator group_begin =
5675     this->input_sections().end();
5676   Input_section_list::const_iterator stub_table =
5677     this->input_sections().end();
5678   Input_section_list::const_iterator group_end = this->input_sections().end();
5679   for (Input_section_list::const_iterator p = this->input_sections().begin();
5680        p != this->input_sections().end();
5681        ++p)
5682     {
5683       section_size_type section_begin_offset =
5684         align_address(off, p->addralign());
5685       section_size_type section_end_offset =
5686         section_begin_offset + p->data_size();
5687
5688       // Check to see if we should group the previously seen sections.
5689       switch (state)
5690         {
5691         case NO_GROUP:
5692           break;
5693
5694         case FINDING_STUB_SECTION:
5695           // Adding this section makes the group larger than GROUP_SIZE.
5696           if (section_end_offset - group_begin_offset >= group_size)
5697             {
5698               if (stubs_always_after_branch)
5699                 {
5700                   gold_assert(group_end != this->input_sections().end());
5701                   this->create_stub_group(group_begin, group_end, group_end,
5702                                           target, &new_relaxed_sections,
5703                                           task);
5704                   state = NO_GROUP;
5705                 }
5706               else
5707                 {
5708                   // But wait, there's more!  Input sections up to
5709                   // stub_group_size bytes after the stub table can be
5710                   // handled by it too.
5711                   state = HAS_STUB_SECTION;
5712                   stub_table = group_end;
5713                   stub_table_end_offset = group_end_offset;
5714                 }
5715             }
5716             break;
5717
5718         case HAS_STUB_SECTION:
5719           // Adding this section makes the post stub-section group larger
5720           // than GROUP_SIZE.
5721           if (section_end_offset - stub_table_end_offset >= group_size)
5722            {
5723              gold_assert(group_end != this->input_sections().end());
5724              this->create_stub_group(group_begin, group_end, stub_table,
5725                                      target, &new_relaxed_sections, task);
5726              state = NO_GROUP;
5727            }
5728            break;
5729
5730           default:
5731             gold_unreachable();
5732         }
5733
5734       // If we see an input section and currently there is no group, start
5735       // a new one.  Skip any empty sections.  We look at the data size
5736       // instead of calling p->relobj()->section_size() to avoid locking.
5737       if ((p->is_input_section() || p->is_relaxed_input_section())
5738           && (p->data_size() != 0))
5739         {
5740           if (state == NO_GROUP)
5741             {
5742               state = FINDING_STUB_SECTION;
5743               group_begin = p;
5744               group_begin_offset = section_begin_offset;
5745             }
5746
5747           // Keep track of the last input section seen.
5748           group_end = p;
5749           group_end_offset = section_end_offset;
5750         }
5751
5752       off = section_end_offset;
5753     }
5754
5755   // Create a stub group for any ungrouped sections.
5756   if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5757     {
5758       gold_assert(group_end != this->input_sections().end());
5759       this->create_stub_group(group_begin, group_end,
5760                               (state == FINDING_STUB_SECTION
5761                                ? group_end
5762                                : stub_table),
5763                                target, &new_relaxed_sections, task);
5764     }
5765
5766   // Convert input section into relaxed input section in a batch.
5767   if (!new_relaxed_sections.empty())
5768     this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5769
5770   // Update the section offsets
5771   for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5772     {
5773       Arm_relobj<big_endian>* arm_relobj =
5774         Arm_relobj<big_endian>::as_arm_relobj(
5775           new_relaxed_sections[i]->relobj());
5776       unsigned int shndx = new_relaxed_sections[i]->shndx();
5777       // Tell Arm_relobj that this input section is converted.
5778       arm_relobj->convert_input_section_to_relaxed_section(shndx);
5779     }
5780 }
5781
5782 // Append non empty text sections in this to LIST in ascending
5783 // order of their position in this.
5784
5785 template<bool big_endian>
5786 void
5787 Arm_output_section<big_endian>::append_text_sections_to_list(
5788     Text_section_list* list)
5789 {
5790   gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5791
5792   for (Input_section_list::const_iterator p = this->input_sections().begin();
5793        p != this->input_sections().end();
5794        ++p)
5795     {
5796       // We only care about plain or relaxed input sections.  We also
5797       // ignore any merged sections.
5798       if (p->is_input_section() || p->is_relaxed_input_section())
5799         list->push_back(Text_section_list::value_type(p->relobj(),
5800                                                       p->shndx()));
5801     }
5802 }
5803
5804 template<bool big_endian>
5805 void
5806 Arm_output_section<big_endian>::fix_exidx_coverage(
5807     Layout* layout,
5808     const Text_section_list& sorted_text_sections,
5809     Symbol_table* symtab,
5810     bool merge_exidx_entries,
5811     const Task* task)
5812 {
5813   // We should only do this for the EXIDX output section.
5814   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5815
5816   // We don't want the relaxation loop to undo these changes, so we discard
5817   // the current saved states and take another one after the fix-up.
5818   this->discard_states();
5819
5820   // Remove all input sections.
5821   uint64_t address = this->address();
5822   typedef std::list<Output_section::Input_section> Input_section_list;
5823   Input_section_list input_sections;
5824   this->reset_address_and_file_offset();
5825   this->get_input_sections(address, std::string(""), &input_sections);
5826
5827   if (!this->input_sections().empty())
5828     gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5829
5830   // Go through all the known input sections and record them.
5831   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5832   typedef Unordered_map<Section_id, const Output_section::Input_section*,
5833                         Section_id_hash> Text_to_exidx_map;
5834   Text_to_exidx_map text_to_exidx_map;
5835   for (Input_section_list::const_iterator p = input_sections.begin();
5836        p != input_sections.end();
5837        ++p)
5838     {
5839       // This should never happen.  At this point, we should only see
5840       // plain EXIDX input sections.
5841       gold_assert(!p->is_relaxed_input_section());
5842       text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5843     }
5844
5845   Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5846
5847   // Go over the sorted text sections.
5848   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5849   Section_id_set processed_input_sections;
5850   for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5851        p != sorted_text_sections.end();
5852        ++p)
5853     {
5854       Relobj* relobj = p->first;
5855       unsigned int shndx = p->second;
5856
5857       Arm_relobj<big_endian>* arm_relobj =
5858          Arm_relobj<big_endian>::as_arm_relobj(relobj);
5859       const Arm_exidx_input_section* exidx_input_section =
5860          arm_relobj->exidx_input_section_by_link(shndx);
5861
5862       // If this text section has no EXIDX section or if the EXIDX section
5863       // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5864       // of the last seen EXIDX section.
5865       if (exidx_input_section == NULL || exidx_input_section->has_errors())
5866         {
5867           exidx_fixup.add_exidx_cantunwind_as_needed();
5868           continue;
5869         }
5870
5871       Relobj* exidx_relobj = exidx_input_section->relobj();
5872       unsigned int exidx_shndx = exidx_input_section->shndx();
5873       Section_id sid(exidx_relobj, exidx_shndx);
5874       Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5875       if (iter == text_to_exidx_map.end())
5876         {
5877           // This is odd.  We have not seen this EXIDX input section before.
5878           // We cannot do fix-up.  If we saw a SECTIONS clause in a script,
5879           // issue a warning instead.  We assume the user knows what he
5880           // or she is doing.  Otherwise, this is an error.
5881           if (layout->script_options()->saw_sections_clause())
5882             gold_warning(_("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           else
5886             gold_error(_("unwinding may not work because EXIDX input section"
5887                          " %u of %s is not in EXIDX output section"),
5888                        exidx_shndx, exidx_relobj->name().c_str());
5889
5890           exidx_fixup.add_exidx_cantunwind_as_needed();
5891           continue;
5892         }
5893
5894       // We need to access the contents of the EXIDX section, lock the
5895       // object here.
5896       Task_lock_obj<Object> tl(task, exidx_relobj);
5897       section_size_type exidx_size;
5898       const unsigned char* exidx_contents =
5899         exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5900
5901       // Fix up coverage and append input section to output data list.
5902       Arm_exidx_section_offset_map* section_offset_map = NULL;
5903       uint32_t deleted_bytes =
5904         exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5905                                                       exidx_contents,
5906                                                       exidx_size,
5907                                                       &section_offset_map);
5908
5909       if (deleted_bytes == exidx_input_section->size())
5910         {
5911           // The whole EXIDX section got merged.  Remove it from output.
5912           gold_assert(section_offset_map == NULL);
5913           exidx_relobj->set_output_section(exidx_shndx, NULL);
5914
5915           // All local symbols defined in this input section will be dropped.
5916           // We need to adjust output local symbol count.
5917           arm_relobj->set_output_local_symbol_count_needs_update();
5918         }
5919       else if (deleted_bytes > 0)
5920         {
5921           // Some entries are merged.  We need to convert this EXIDX input
5922           // section into a relaxed section.
5923           gold_assert(section_offset_map != NULL);
5924
5925           Arm_exidx_merged_section* merged_section =
5926             new Arm_exidx_merged_section(*exidx_input_section,
5927                                          *section_offset_map, deleted_bytes);
5928           merged_section->build_contents(exidx_contents, exidx_size);
5929
5930           const std::string secname = exidx_relobj->section_name(exidx_shndx);
5931           this->add_relaxed_input_section(layout, merged_section, secname);
5932           arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5933
5934           // All local symbols defined in discarded portions of this input
5935           // section will be dropped.  We need to adjust output local symbol
5936           // count.
5937           arm_relobj->set_output_local_symbol_count_needs_update();
5938         }
5939       else
5940         {
5941           // Just add back the EXIDX input section.
5942           gold_assert(section_offset_map == NULL);
5943           const Output_section::Input_section* pis = iter->second;
5944           gold_assert(pis->is_input_section());
5945           this->add_script_input_section(*pis);
5946         }
5947
5948       processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5949     }
5950
5951   // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5952   exidx_fixup.add_exidx_cantunwind_as_needed();
5953
5954   // Remove any known EXIDX input sections that are not processed.
5955   for (Input_section_list::const_iterator p = input_sections.begin();
5956        p != input_sections.end();
5957        ++p)
5958     {
5959       if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5960           == processed_input_sections.end())
5961         {
5962           // We discard a known EXIDX section because its linked
5963           // text section has been folded by ICF.  We also discard an
5964           // EXIDX section with error, the output does not matter in this
5965           // case.  We do this to avoid triggering asserts.
5966           Arm_relobj<big_endian>* arm_relobj =
5967             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5968           const Arm_exidx_input_section* exidx_input_section =
5969             arm_relobj->exidx_input_section_by_shndx(p->shndx());
5970           gold_assert(exidx_input_section != NULL);
5971           if (!exidx_input_section->has_errors())
5972             {
5973               unsigned int text_shndx = exidx_input_section->link();
5974               gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5975             }
5976
5977           // Remove this from link.  We also need to recount the
5978           // local symbols.
5979           p->relobj()->set_output_section(p->shndx(), NULL);
5980           arm_relobj->set_output_local_symbol_count_needs_update();
5981         }
5982     }
5983
5984   // Link exidx output section to the first seen output section and
5985   // set correct entry size.
5986   this->set_link_section(exidx_fixup.first_output_text_section());
5987   this->set_entsize(8);
5988
5989   // Make changes permanent.
5990   this->save_states();
5991   this->set_section_offsets_need_adjustment();
5992 }
5993
5994 // Link EXIDX output sections to text output sections.
5995
5996 template<bool big_endian>
5997 void
5998 Arm_output_section<big_endian>::set_exidx_section_link()
5999 {
6000   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
6001   if (!this->input_sections().empty())
6002     {
6003       Input_section_list::const_iterator p = this->input_sections().begin();
6004       Arm_relobj<big_endian>* arm_relobj =
6005         Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6006       unsigned exidx_shndx = p->shndx();
6007       const Arm_exidx_input_section* exidx_input_section =
6008         arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6009       gold_assert(exidx_input_section != NULL);
6010       unsigned int text_shndx = exidx_input_section->link();
6011       Output_section* os = arm_relobj->output_section(text_shndx);
6012       this->set_link_section(os);
6013     }
6014 }
6015
6016 // Arm_relobj methods.
6017
6018 // Determine if an input section is scannable for stub processing.  SHDR is
6019 // the header of the section and SHNDX is the section index.  OS is the output
6020 // section for the input section and SYMTAB is the global symbol table used to
6021 // look up ICF information.
6022
6023 template<bool big_endian>
6024 bool
6025 Arm_relobj<big_endian>::section_is_scannable(
6026     const elfcpp::Shdr<32, big_endian>& shdr,
6027     unsigned int shndx,
6028     const Output_section* os,
6029     const Symbol_table* symtab)
6030 {
6031   // Skip any empty sections, unallocated sections or sections whose
6032   // type are not SHT_PROGBITS.
6033   if (shdr.get_sh_size() == 0
6034       || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6035       || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6036     return false;
6037
6038   // Skip any discarded or ICF'ed sections.
6039   if (os == NULL || symtab->is_section_folded(this, shndx))
6040     return false;
6041
6042   // If this requires special offset handling, check to see if it is
6043   // a relaxed section.  If this is not, then it is a merged section that
6044   // we cannot handle.
6045   if (this->is_output_section_offset_invalid(shndx))
6046     {
6047       const Output_relaxed_input_section* poris =
6048         os->find_relaxed_input_section(this, shndx);
6049       if (poris == NULL)
6050         return false;
6051     }
6052
6053   return true;
6054 }
6055
6056 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6057 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6058
6059 template<bool big_endian>
6060 bool
6061 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6062     const elfcpp::Shdr<32, big_endian>& shdr,
6063     const Relobj::Output_sections& out_sections,
6064     const Symbol_table* symtab,
6065     const unsigned char* pshdrs)
6066 {
6067   unsigned int sh_type = shdr.get_sh_type();
6068   if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6069     return false;
6070
6071   // Ignore empty section.
6072   off_t sh_size = shdr.get_sh_size();
6073   if (sh_size == 0)
6074     return false;
6075
6076   // Ignore reloc section with unexpected symbol table.  The
6077   // error will be reported in the final link.
6078   if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6079     return false;
6080
6081   unsigned int reloc_size;
6082   if (sh_type == elfcpp::SHT_REL)
6083     reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6084   else
6085     reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6086
6087   // Ignore reloc section with unexpected entsize or uneven size.
6088   // The error will be reported in the final link.
6089   if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6090     return false;
6091
6092   // Ignore reloc section with bad info.  This error will be
6093   // reported in the final link.
6094   unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6095   if (index >= this->shnum())
6096     return false;
6097
6098   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6099   const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6100   return this->section_is_scannable(text_shdr, index,
6101                                    out_sections[index], symtab);
6102 }
6103
6104 // Return the output address of either a plain input section or a relaxed
6105 // input section.  SHNDX is the section index.  We define and use this
6106 // instead of calling Output_section::output_address because that is slow
6107 // for large output.
6108
6109 template<bool big_endian>
6110 Arm_address
6111 Arm_relobj<big_endian>::simple_input_section_output_address(
6112     unsigned int shndx,
6113     Output_section* os)
6114 {
6115   if (this->is_output_section_offset_invalid(shndx))
6116     {
6117       const Output_relaxed_input_section* poris =
6118         os->find_relaxed_input_section(this, shndx);
6119       // We do not handle merged sections here.
6120       gold_assert(poris != NULL);
6121       return poris->address();
6122     }
6123   else
6124     return os->address() + this->get_output_section_offset(shndx);
6125 }
6126
6127 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6128 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6129
6130 template<bool big_endian>
6131 bool
6132 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6133     const elfcpp::Shdr<32, big_endian>& shdr,
6134     unsigned int shndx,
6135     Output_section* os,
6136     const Symbol_table* symtab)
6137 {
6138   if (!this->section_is_scannable(shdr, shndx, os, symtab))
6139     return false;
6140
6141   // If the section does not cross any 4K-boundaries, it does not need to
6142   // be scanned.
6143   Arm_address address = this->simple_input_section_output_address(shndx, os);
6144   if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6145     return false;
6146
6147   return true;
6148 }
6149
6150 // Scan a section for Cortex-A8 workaround.
6151
6152 template<bool big_endian>
6153 void
6154 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6155     const elfcpp::Shdr<32, big_endian>& shdr,
6156     unsigned int shndx,
6157     Output_section* os,
6158     Target_arm<big_endian>* arm_target)
6159 {
6160   // Look for the first mapping symbol in this section.  It should be
6161   // at (shndx, 0).
6162   Mapping_symbol_position section_start(shndx, 0);
6163   typename Mapping_symbols_info::const_iterator p =
6164     this->mapping_symbols_info_.lower_bound(section_start);
6165
6166   // There are no mapping symbols for this section.  Treat it as a data-only
6167   // section.  Issue a warning if section is marked as containing
6168   // instructions.
6169   if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6170     {
6171       if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6172         gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6173                        "erratum because it has no mapping symbols."),
6174                      shndx, this->name().c_str());
6175       return;
6176     }
6177
6178   Arm_address output_address =
6179     this->simple_input_section_output_address(shndx, os);
6180
6181   // Get the section contents.
6182   section_size_type input_view_size = 0;
6183   const unsigned char* input_view =
6184     this->section_contents(shndx, &input_view_size, false);
6185
6186   // We need to go through the mapping symbols to determine what to
6187   // scan.  There are two reasons.  First, we should look at THUMB code and
6188   // THUMB code only.  Second, we only want to look at the 4K-page boundary
6189   // to speed up the scanning.
6190
6191   while (p != this->mapping_symbols_info_.end()
6192         && p->first.first == shndx)
6193     {
6194       typename Mapping_symbols_info::const_iterator next =
6195         this->mapping_symbols_info_.upper_bound(p->first);
6196
6197       // Only scan part of a section with THUMB code.
6198       if (p->second == 't')
6199         {
6200           // Determine the end of this range.
6201           section_size_type span_start =
6202             convert_to_section_size_type(p->first.second);
6203           section_size_type span_end;
6204           if (next != this->mapping_symbols_info_.end()
6205               && next->first.first == shndx)
6206             span_end = convert_to_section_size_type(next->first.second);
6207           else
6208             span_end = convert_to_section_size_type(shdr.get_sh_size());
6209
6210           if (((span_start + output_address) & ~0xfffUL)
6211               != ((span_end + output_address - 1) & ~0xfffUL))
6212             {
6213               arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6214                                                           span_start, span_end,
6215                                                           input_view,
6216                                                           output_address);
6217             }
6218         }
6219
6220       p = next;
6221     }
6222 }
6223
6224 // Scan relocations for stub generation.
6225
6226 template<bool big_endian>
6227 void
6228 Arm_relobj<big_endian>::scan_sections_for_stubs(
6229     Target_arm<big_endian>* arm_target,
6230     const Symbol_table* symtab,
6231     const Layout* layout)
6232 {
6233   unsigned int shnum = this->shnum();
6234   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6235
6236   // Read the section headers.
6237   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6238                                                shnum * shdr_size,
6239                                                true, true);
6240
6241   // To speed up processing, we set up hash tables for fast lookup of
6242   // input offsets to output addresses.
6243   this->initialize_input_to_output_maps();
6244
6245   const Relobj::Output_sections& out_sections(this->output_sections());
6246
6247   Relocate_info<32, big_endian> relinfo;
6248   relinfo.symtab = symtab;
6249   relinfo.layout = layout;
6250   relinfo.object = this;
6251
6252   // Do relocation stubs scanning.
6253   const unsigned char* p = pshdrs + shdr_size;
6254   for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6255     {
6256       const elfcpp::Shdr<32, big_endian> shdr(p);
6257       if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6258                                                   pshdrs))
6259         {
6260           unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6261           Arm_address output_offset = this->get_output_section_offset(index);
6262           Arm_address output_address;
6263           if (output_offset != invalid_address)
6264             output_address = out_sections[index]->address() + output_offset;
6265           else
6266             {
6267               // Currently this only happens for a relaxed section.
6268               const Output_relaxed_input_section* poris =
6269               out_sections[index]->find_relaxed_input_section(this, index);
6270               gold_assert(poris != NULL);
6271               output_address = poris->address();
6272             }
6273
6274           // Get the relocations.
6275           const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6276                                                         shdr.get_sh_size(),
6277                                                         true, false);
6278
6279           // Get the section contents.  This does work for the case in which
6280           // we modify the contents of an input section.  We need to pass the
6281           // output view under such circumstances.
6282           section_size_type input_view_size = 0;
6283           const unsigned char* input_view =
6284             this->section_contents(index, &input_view_size, false);
6285
6286           relinfo.reloc_shndx = i;
6287           relinfo.data_shndx = index;
6288           unsigned int sh_type = shdr.get_sh_type();
6289           unsigned int reloc_size;
6290           if (sh_type == elfcpp::SHT_REL)
6291             reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6292           else
6293             reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6294
6295           Output_section* os = out_sections[index];
6296           arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6297                                              shdr.get_sh_size() / reloc_size,
6298                                              os,
6299                                              output_offset == invalid_address,
6300                                              input_view, output_address,
6301                                              input_view_size);
6302         }
6303     }
6304
6305   // Do Cortex-A8 erratum stubs scanning.  This has to be done for a section
6306   // after its relocation section, if there is one, is processed for
6307   // relocation stubs.  Merging this loop with the one above would have been
6308   // complicated since we would have had to make sure that relocation stub
6309   // scanning is done first.
6310   if (arm_target->fix_cortex_a8())
6311     {
6312       const unsigned char* p = pshdrs + shdr_size;
6313       for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6314         {
6315           const elfcpp::Shdr<32, big_endian> shdr(p);
6316           if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6317                                                           out_sections[i],
6318                                                           symtab))
6319             this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6320                                                      arm_target);
6321         }
6322     }
6323
6324   // After we've done the relocations, we release the hash tables,
6325   // since we no longer need them.
6326   this->free_input_to_output_maps();
6327 }
6328
6329 // Count the local symbols.  The ARM backend needs to know if a symbol
6330 // is a THUMB function or not.  For global symbols, it is easy because
6331 // the Symbol object keeps the ELF symbol type.  For local symbol it is
6332 // harder because we cannot access this information.   So we override the
6333 // do_count_local_symbol in parent and scan local symbols to mark
6334 // THUMB functions.  This is not the most efficient way but I do not want to
6335 // slow down other ports by calling a per symbol target hook inside
6336 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6337
6338 template<bool big_endian>
6339 void
6340 Arm_relobj<big_endian>::do_count_local_symbols(
6341     Stringpool_template<char>* pool,
6342     Stringpool_template<char>* dynpool)
6343 {
6344   // We need to fix-up the values of any local symbols whose type are
6345   // STT_ARM_TFUNC.
6346
6347   // Ask parent to count the local symbols.
6348   Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6349   const unsigned int loccount = this->local_symbol_count();
6350   if (loccount == 0)
6351     return;
6352
6353   // Initialize the thumb function bit-vector.
6354   std::vector<bool> empty_vector(loccount, false);
6355   this->local_symbol_is_thumb_function_.swap(empty_vector);
6356
6357   // Read the symbol table section header.
6358   const unsigned int symtab_shndx = this->symtab_shndx();
6359   elfcpp::Shdr<32, big_endian>
6360       symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6361   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6362
6363   // Read the local symbols.
6364   const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6365   gold_assert(loccount == symtabshdr.get_sh_info());
6366   off_t locsize = loccount * sym_size;
6367   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6368                                               locsize, true, true);
6369
6370   // For mapping symbol processing, we need to read the symbol names.
6371   unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6372   if (strtab_shndx >= this->shnum())
6373     {
6374       this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6375       return;
6376     }
6377
6378   elfcpp::Shdr<32, big_endian>
6379     strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6380   if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6381     {
6382       this->error(_("symbol table name section has wrong type: %u"),
6383                   static_cast<unsigned int>(strtabshdr.get_sh_type()));
6384       return;
6385     }
6386   const char* pnames =
6387     reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6388                                                  strtabshdr.get_sh_size(),
6389                                                  false, false));
6390
6391   // Loop over the local symbols and mark any local symbols pointing
6392   // to THUMB functions.
6393
6394   // Skip the first dummy symbol.
6395   psyms += sym_size;
6396   typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6397     this->local_values();
6398   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6399     {
6400       elfcpp::Sym<32, big_endian> sym(psyms);
6401       elfcpp::STT st_type = sym.get_st_type();
6402       Symbol_value<32>& lv((*plocal_values)[i]);
6403       Arm_address input_value = lv.input_value();
6404
6405       // Check to see if this is a mapping symbol.
6406       const char* sym_name = pnames + sym.get_st_name();
6407       if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6408         {
6409           bool is_ordinary;
6410           unsigned int input_shndx =
6411             this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6412           gold_assert(is_ordinary);
6413
6414           // Strip of LSB in case this is a THUMB symbol.
6415           Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6416           this->mapping_symbols_info_[msp] = sym_name[1];
6417         }
6418
6419       if (st_type == elfcpp::STT_ARM_TFUNC
6420           || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6421         {
6422           // This is a THUMB function.  Mark this and canonicalize the
6423           // symbol value by setting LSB.
6424           this->local_symbol_is_thumb_function_[i] = true;
6425           if ((input_value & 1) == 0)
6426             lv.set_input_value(input_value | 1);
6427         }
6428     }
6429 }
6430
6431 // Relocate sections.
6432 template<bool big_endian>
6433 void
6434 Arm_relobj<big_endian>::do_relocate_sections(
6435     const Symbol_table* symtab,
6436     const Layout* layout,
6437     const unsigned char* pshdrs,
6438     Output_file* of,
6439     typename Sized_relobj_file<32, big_endian>::Views* pviews)
6440 {
6441   // Call parent to relocate sections.
6442   Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6443                                                           pshdrs, of, pviews);
6444
6445   // We do not generate stubs if doing a relocatable link.
6446   if (parameters->options().relocatable())
6447     return;
6448
6449   // Relocate stub tables.
6450   unsigned int shnum = this->shnum();
6451
6452   Target_arm<big_endian>* arm_target =
6453     Target_arm<big_endian>::default_target();
6454
6455   Relocate_info<32, big_endian> relinfo;
6456   relinfo.symtab = symtab;
6457   relinfo.layout = layout;
6458   relinfo.object = this;
6459
6460   for (unsigned int i = 1; i < shnum; ++i)
6461     {
6462       Arm_input_section<big_endian>* arm_input_section =
6463         arm_target->find_arm_input_section(this, i);
6464
6465       if (arm_input_section != NULL
6466           && arm_input_section->is_stub_table_owner()
6467           && !arm_input_section->stub_table()->empty())
6468         {
6469           // We cannot discard a section if it owns a stub table.
6470           Output_section* os = this->output_section(i);
6471           gold_assert(os != NULL);
6472
6473           relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6474           relinfo.reloc_shdr = NULL;
6475           relinfo.data_shndx = i;
6476           relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6477
6478           gold_assert((*pviews)[i].view != NULL);
6479
6480           // We are passed the output section view.  Adjust it to cover the
6481           // stub table only.
6482           Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6483           gold_assert((stub_table->address() >= (*pviews)[i].address)
6484                       && ((stub_table->address() + stub_table->data_size())
6485                           <= (*pviews)[i].address + (*pviews)[i].view_size));
6486
6487           off_t offset = stub_table->address() - (*pviews)[i].address;
6488           unsigned char* view = (*pviews)[i].view + offset;
6489           Arm_address address = stub_table->address();
6490           section_size_type view_size = stub_table->data_size();
6491
6492           stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6493                                      view_size);
6494         }
6495
6496       // Apply Cortex A8 workaround if applicable.
6497       if (this->section_has_cortex_a8_workaround(i))
6498         {
6499           unsigned char* view = (*pviews)[i].view;
6500           Arm_address view_address = (*pviews)[i].address;
6501           section_size_type view_size = (*pviews)[i].view_size;
6502           Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6503
6504           // Adjust view to cover section.
6505           Output_section* os = this->output_section(i);
6506           gold_assert(os != NULL);
6507           Arm_address section_address =
6508             this->simple_input_section_output_address(i, os);
6509           uint64_t section_size = this->section_size(i);
6510
6511           gold_assert(section_address >= view_address
6512                       && ((section_address + section_size)
6513                           <= (view_address + view_size)));
6514
6515           unsigned char* section_view = view + (section_address - view_address);
6516
6517           // Apply the Cortex-A8 workaround to the output address range
6518           // corresponding to this input section.
6519           stub_table->apply_cortex_a8_workaround_to_address_range(
6520               arm_target,
6521               section_view,
6522               section_address,
6523               section_size);
6524         }
6525     }
6526 }
6527
6528 // Find the linked text section of an EXIDX section by looking at the first
6529 // relocation.  4.4.1 of the EHABI specifications says that an EXIDX section
6530 // must be linked to its associated code section via the sh_link field of
6531 // its section header.  However, some tools are broken and the link is not
6532 // always set.  LD just drops such an EXIDX section silently, causing the
6533 // associated code not unwindabled.   Here we try a little bit harder to
6534 // discover the linked code section.
6535 //
6536 // PSHDR points to the section header of a relocation section of an EXIDX
6537 // section.  If we can find a linked text section, return true and
6538 // store the text section index in the location PSHNDX.  Otherwise
6539 // return false.
6540
6541 template<bool big_endian>
6542 bool
6543 Arm_relobj<big_endian>::find_linked_text_section(
6544     const unsigned char* pshdr,
6545     const unsigned char* psyms,
6546     unsigned int* pshndx)
6547 {
6548   elfcpp::Shdr<32, big_endian> shdr(pshdr);
6549
6550   // If there is no relocation, we cannot find the linked text section.
6551   size_t reloc_size;
6552   if (shdr.get_sh_type() == elfcpp::SHT_REL)
6553       reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6554   else
6555       reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6556   size_t reloc_count = shdr.get_sh_size() / reloc_size;
6557
6558   // Get the relocations.
6559   const unsigned char* prelocs =
6560       this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6561
6562   // Find the REL31 relocation for the first word of the first EXIDX entry.
6563   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6564     {
6565       Arm_address r_offset;
6566       typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6567       if (shdr.get_sh_type() == elfcpp::SHT_REL)
6568         {
6569           typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6570           r_info = reloc.get_r_info();
6571           r_offset = reloc.get_r_offset();
6572         }
6573       else
6574         {
6575           typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6576           r_info = reloc.get_r_info();
6577           r_offset = reloc.get_r_offset();
6578         }
6579
6580       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6581       if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6582         continue;
6583
6584       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6585       if (r_sym == 0
6586           || r_sym >= this->local_symbol_count()
6587           || r_offset != 0)
6588         continue;
6589
6590       // This is the relocation for the first word of the first EXIDX entry.
6591       // We expect to see a local section symbol.
6592       const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6593       elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6594       if (sym.get_st_type() == elfcpp::STT_SECTION)
6595         {
6596           bool is_ordinary;
6597           *pshndx =
6598             this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6599           gold_assert(is_ordinary);
6600           return true;
6601         }
6602       else
6603         return false;
6604     }
6605
6606   return false;
6607 }
6608
6609 // Make an EXIDX input section object for an EXIDX section whose index is
6610 // SHNDX.  SHDR is the section header of the EXIDX section and TEXT_SHNDX
6611 // is the section index of the linked text section.
6612
6613 template<bool big_endian>
6614 void
6615 Arm_relobj<big_endian>::make_exidx_input_section(
6616     unsigned int shndx,
6617     const elfcpp::Shdr<32, big_endian>& shdr,
6618     unsigned int text_shndx,
6619     const elfcpp::Shdr<32, big_endian>& text_shdr)
6620 {
6621   // Create an Arm_exidx_input_section object for this EXIDX section.
6622   Arm_exidx_input_section* exidx_input_section =
6623     new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6624                                 shdr.get_sh_addralign(),
6625                                 text_shdr.get_sh_size());
6626
6627   gold_assert(this->exidx_section_map_[shndx] == NULL);
6628   this->exidx_section_map_[shndx] = exidx_input_section;
6629
6630   if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6631     {
6632       gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6633                  this->section_name(shndx).c_str(), shndx, text_shndx,
6634                  this->name().c_str());
6635       exidx_input_section->set_has_errors();
6636     }
6637   else if (this->exidx_section_map_[text_shndx] != NULL)
6638     {
6639       unsigned other_exidx_shndx =
6640         this->exidx_section_map_[text_shndx]->shndx();
6641       gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6642                    "%s(%u) in %s"),
6643                  this->section_name(shndx).c_str(), shndx,
6644                  this->section_name(other_exidx_shndx).c_str(),
6645                  other_exidx_shndx, this->section_name(text_shndx).c_str(),
6646                  text_shndx, this->name().c_str());
6647       exidx_input_section->set_has_errors();
6648     }
6649   else
6650      this->exidx_section_map_[text_shndx] = exidx_input_section;
6651
6652   // Check section flags of text section.
6653   if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6654     {
6655       gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6656                    " in %s"),
6657                  this->section_name(shndx).c_str(), shndx,
6658                  this->section_name(text_shndx).c_str(), text_shndx,
6659                  this->name().c_str());
6660       exidx_input_section->set_has_errors();
6661     }
6662   else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6663     // I would like to make this an error but currently ld just ignores
6664     // this.
6665     gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6666                    "%s(%u) in %s"),
6667                  this->section_name(shndx).c_str(), shndx,
6668                  this->section_name(text_shndx).c_str(), text_shndx,
6669                  this->name().c_str());
6670 }
6671
6672 // Read the symbol information.
6673
6674 template<bool big_endian>
6675 void
6676 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6677 {
6678   // Call parent class to read symbol information.
6679   Sized_relobj_file<32, big_endian>::do_read_symbols(sd);
6680
6681   // If this input file is a binary file, it has no processor
6682   // specific flags and attributes section.
6683   Input_file::Format format = this->input_file()->format();
6684   if (format != Input_file::FORMAT_ELF)
6685     {
6686       gold_assert(format == Input_file::FORMAT_BINARY);
6687       this->merge_flags_and_attributes_ = false;
6688       return;
6689     }
6690
6691   // Read processor-specific flags in ELF file header.
6692   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6693                                               elfcpp::Elf_sizes<32>::ehdr_size,
6694                                               true, false);
6695   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6696   this->processor_specific_flags_ = ehdr.get_e_flags();
6697
6698   // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6699   // sections.
6700   std::vector<unsigned int> deferred_exidx_sections;
6701   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6702   const unsigned char* pshdrs = sd->section_headers->data();
6703   const unsigned char* ps = pshdrs + shdr_size;
6704   bool must_merge_flags_and_attributes = false;
6705   for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6706     {
6707       elfcpp::Shdr<32, big_endian> shdr(ps);
6708
6709       // Sometimes an object has no contents except the section name string
6710       // table and an empty symbol table with the undefined symbol.  We
6711       // don't want to merge processor-specific flags from such an object.
6712       if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6713         {
6714           // Symbol table is not empty.
6715           const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6716              elfcpp::Elf_sizes<32>::sym_size;
6717           if (shdr.get_sh_size() > sym_size)
6718             must_merge_flags_and_attributes = true;
6719         }
6720       else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6721         // If this is neither an empty symbol table nor a string table,
6722         // be conservative.
6723         must_merge_flags_and_attributes = true;
6724
6725       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6726         {
6727           gold_assert(this->attributes_section_data_ == NULL);
6728           section_offset_type section_offset = shdr.get_sh_offset();
6729           section_size_type section_size =
6730             convert_to_section_size_type(shdr.get_sh_size());
6731           const unsigned char* view =
6732              this->get_view(section_offset, section_size, true, false);
6733           this->attributes_section_data_ =
6734             new Attributes_section_data(view, section_size);
6735         }
6736       else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6737         {
6738           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6739           if (text_shndx == elfcpp::SHN_UNDEF)
6740             deferred_exidx_sections.push_back(i);
6741           else
6742             {
6743               elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6744                                                      + text_shndx * shdr_size);
6745               this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6746             }
6747           // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6748           if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6749             gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6750                          this->section_name(i).c_str(), this->name().c_str());
6751         }
6752     }
6753
6754   // This is rare.
6755   if (!must_merge_flags_and_attributes)
6756     {
6757       gold_assert(deferred_exidx_sections.empty());
6758       this->merge_flags_and_attributes_ = false;
6759       return;
6760     }
6761
6762   // Some tools are broken and they do not set the link of EXIDX sections.
6763   // We look at the first relocation to figure out the linked sections.
6764   if (!deferred_exidx_sections.empty())
6765     {
6766       // We need to go over the section headers again to find the mapping
6767       // from sections being relocated to their relocation sections.  This is
6768       // a bit inefficient as we could do that in the loop above.  However,
6769       // we do not expect any deferred EXIDX sections normally.  So we do not
6770       // want to slow down the most common path.
6771       typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6772       Reloc_map reloc_map;
6773       ps = pshdrs + shdr_size;
6774       for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6775         {
6776           elfcpp::Shdr<32, big_endian> shdr(ps);
6777           elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6778           if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6779             {
6780               unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6781               if (info_shndx >= this->shnum())
6782                 gold_error(_("relocation section %u has invalid info %u"),
6783                            i, info_shndx);
6784               Reloc_map::value_type value(info_shndx, i);
6785               std::pair<Reloc_map::iterator, bool> result =
6786                 reloc_map.insert(value);
6787               if (!result.second)
6788                 gold_error(_("section %u has multiple relocation sections "
6789                              "%u and %u"),
6790                            info_shndx, i, reloc_map[info_shndx]);
6791             }
6792         }
6793
6794       // Read the symbol table section header.
6795       const unsigned int symtab_shndx = this->symtab_shndx();
6796       elfcpp::Shdr<32, big_endian>
6797           symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6798       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6799
6800       // Read the local symbols.
6801       const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6802       const unsigned int loccount = this->local_symbol_count();
6803       gold_assert(loccount == symtabshdr.get_sh_info());
6804       off_t locsize = loccount * sym_size;
6805       const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6806                                                   locsize, true, true);
6807
6808       // Process the deferred EXIDX sections.
6809       for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6810         {
6811           unsigned int shndx = deferred_exidx_sections[i];
6812           elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6813           unsigned int text_shndx = elfcpp::SHN_UNDEF;
6814           Reloc_map::const_iterator it = reloc_map.find(shndx);
6815           if (it != reloc_map.end())
6816             find_linked_text_section(pshdrs + it->second * shdr_size,
6817                                      psyms, &text_shndx);
6818           elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6819                                                  + text_shndx * shdr_size);
6820           this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6821         }
6822     }
6823 }
6824
6825 // Process relocations for garbage collection.  The ARM target uses .ARM.exidx
6826 // sections for unwinding.  These sections are referenced implicitly by
6827 // text sections linked in the section headers.  If we ignore these implicit
6828 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6829 // will be garbage-collected incorrectly.  Hence we override the same function
6830 // in the base class to handle these implicit references.
6831
6832 template<bool big_endian>
6833 void
6834 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6835                                              Layout* layout,
6836                                              Read_relocs_data* rd)
6837 {
6838   // First, call base class method to process relocations in this object.
6839   Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6840
6841   // If --gc-sections is not specified, there is nothing more to do.
6842   // This happens when --icf is used but --gc-sections is not.
6843   if (!parameters->options().gc_sections())
6844     return;
6845
6846   unsigned int shnum = this->shnum();
6847   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6848   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6849                                                shnum * shdr_size,
6850                                                true, true);
6851
6852   // Scan section headers for sections of type SHT_ARM_EXIDX.  Add references
6853   // to these from the linked text sections.
6854   const unsigned char* ps = pshdrs + shdr_size;
6855   for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6856     {
6857       elfcpp::Shdr<32, big_endian> shdr(ps);
6858       if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6859         {
6860           // Found an .ARM.exidx section, add it to the set of reachable
6861           // sections from its linked text section.
6862           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6863           symtab->gc()->add_reference(this, text_shndx, this, i);
6864         }
6865     }
6866 }
6867
6868 // Update output local symbol count.  Owing to EXIDX entry merging, some local
6869 // symbols  will be removed in output.  Adjust output local symbol count
6870 // accordingly.  We can only changed the static output local symbol count.  It
6871 // is too late to change the dynamic symbols.
6872
6873 template<bool big_endian>
6874 void
6875 Arm_relobj<big_endian>::update_output_local_symbol_count()
6876 {
6877   // Caller should check that this needs updating.  We want caller checking
6878   // because output_local_symbol_count_needs_update() is most likely inlined.
6879   gold_assert(this->output_local_symbol_count_needs_update_);
6880
6881   gold_assert(this->symtab_shndx() != -1U);
6882   if (this->symtab_shndx() == 0)
6883     {
6884       // This object has no symbols.  Weird but legal.
6885       return;
6886     }
6887
6888   // Read the symbol table section header.
6889   const unsigned int symtab_shndx = this->symtab_shndx();
6890   elfcpp::Shdr<32, big_endian>
6891     symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6892   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6893
6894   // Read the local symbols.
6895   const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6896   const unsigned int loccount = this->local_symbol_count();
6897   gold_assert(loccount == symtabshdr.get_sh_info());
6898   off_t locsize = loccount * sym_size;
6899   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6900                                               locsize, true, true);
6901
6902   // Loop over the local symbols.
6903
6904   typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6905      Output_sections;
6906   const Output_sections& out_sections(this->output_sections());
6907   unsigned int shnum = this->shnum();
6908   unsigned int count = 0;
6909   // Skip the first, dummy, symbol.
6910   psyms += sym_size;
6911   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6912     {
6913       elfcpp::Sym<32, big_endian> sym(psyms);
6914
6915       Symbol_value<32>& lv((*this->local_values())[i]);
6916
6917       // This local symbol was already discarded by do_count_local_symbols.
6918       if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6919         continue;
6920
6921       bool is_ordinary;
6922       unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6923                                                   &is_ordinary);
6924
6925       if (shndx < shnum)
6926         {
6927           Output_section* os = out_sections[shndx];
6928
6929           // This local symbol no longer has an output section.  Discard it.
6930           if (os == NULL)
6931             {
6932               lv.set_no_output_symtab_entry();
6933               continue;
6934             }
6935
6936           // Currently we only discard parts of EXIDX input sections.
6937           // We explicitly check for a merged EXIDX input section to avoid
6938           // calling Output_section_data::output_offset unless necessary.
6939           if ((this->get_output_section_offset(shndx) == invalid_address)
6940               && (this->exidx_input_section_by_shndx(shndx) != NULL))
6941             {
6942               section_offset_type output_offset =
6943                 os->output_offset(this, shndx, lv.input_value());
6944               if (output_offset == -1)
6945                 {
6946                   // This symbol is defined in a part of an EXIDX input section
6947                   // that is discarded due to entry merging.
6948                   lv.set_no_output_symtab_entry();
6949                   continue;
6950                 }
6951             }
6952         }
6953
6954       ++count;
6955     }
6956
6957   this->set_output_local_symbol_count(count);
6958   this->output_local_symbol_count_needs_update_ = false;
6959 }
6960
6961 // Arm_dynobj methods.
6962
6963 // Read the symbol information.
6964
6965 template<bool big_endian>
6966 void
6967 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6968 {
6969   // Call parent class to read symbol information.
6970   Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6971
6972   // Read processor-specific flags in ELF file header.
6973   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6974                                               elfcpp::Elf_sizes<32>::ehdr_size,
6975                                               true, false);
6976   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6977   this->processor_specific_flags_ = ehdr.get_e_flags();
6978
6979   // Read the attributes section if there is one.
6980   // We read from the end because gas seems to put it near the end of
6981   // the section headers.
6982   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6983   const unsigned char* ps =
6984     sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6985   for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6986     {
6987       elfcpp::Shdr<32, big_endian> shdr(ps);
6988       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6989         {
6990           section_offset_type section_offset = shdr.get_sh_offset();
6991           section_size_type section_size =
6992             convert_to_section_size_type(shdr.get_sh_size());
6993           const unsigned char* view =
6994             this->get_view(section_offset, section_size, true, false);
6995           this->attributes_section_data_ =
6996             new Attributes_section_data(view, section_size);
6997           break;
6998         }
6999     }
7000 }
7001
7002 // Stub_addend_reader methods.
7003
7004 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7005
7006 template<bool big_endian>
7007 elfcpp::Elf_types<32>::Elf_Swxword
7008 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7009     unsigned int r_type,
7010     const unsigned char* view,
7011     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7012 {
7013   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
7014
7015   switch (r_type)
7016     {
7017     case elfcpp::R_ARM_CALL:
7018     case elfcpp::R_ARM_JUMP24:
7019     case elfcpp::R_ARM_PLT32:
7020       {
7021         typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7022         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7023         Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7024         return Bits<26>::sign_extend32(val << 2);
7025       }
7026
7027     case elfcpp::R_ARM_THM_CALL:
7028     case elfcpp::R_ARM_THM_JUMP24:
7029     case elfcpp::R_ARM_THM_XPC22:
7030       {
7031         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7032         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7033         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7034         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7035         return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7036       }
7037
7038     case elfcpp::R_ARM_THM_JUMP19:
7039       {
7040         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7041         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7042         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7043         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7044         return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7045       }
7046
7047     default:
7048       gold_unreachable();
7049     }
7050 }
7051
7052 // Arm_output_data_got methods.
7053
7054 // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
7055 // The first one is initialized to be 1, which is the module index for
7056 // the main executable and the second one 0.  A reloc of the type
7057 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7058 // be applied by gold.  GSYM is a global symbol.
7059 //
7060 template<bool big_endian>
7061 void
7062 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7063     unsigned int got_type,
7064     Symbol* gsym)
7065 {
7066   if (gsym->has_got_offset(got_type))
7067     return;
7068
7069   // We are doing a static link.  Just mark it as belong to module 1,
7070   // the executable.
7071   unsigned int got_offset = this->add_constant(1);
7072   gsym->set_got_offset(got_type, got_offset);
7073   got_offset = this->add_constant(0);
7074   this->static_relocs_.push_back(Static_reloc(got_offset,
7075                                               elfcpp::R_ARM_TLS_DTPOFF32,
7076                                               gsym));
7077 }
7078
7079 // Same as the above but for a local symbol.
7080
7081 template<bool big_endian>
7082 void
7083 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7084   unsigned int got_type,
7085   Sized_relobj_file<32, big_endian>* object,
7086   unsigned int index)
7087 {
7088   if (object->local_has_got_offset(index, got_type))
7089     return;
7090
7091   // We are doing a static link.  Just mark it as belong to module 1,
7092   // the executable.
7093   unsigned int got_offset = this->add_constant(1);
7094   object->set_local_got_offset(index, got_type, got_offset);
7095   got_offset = this->add_constant(0);
7096   this->static_relocs_.push_back(Static_reloc(got_offset,
7097                                               elfcpp::R_ARM_TLS_DTPOFF32,
7098                                               object, index));
7099 }
7100
7101 template<bool big_endian>
7102 void
7103 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7104 {
7105   // Call parent to write out GOT.
7106   Output_data_got<32, big_endian>::do_write(of);
7107
7108   // We are done if there is no fix up.
7109   if (this->static_relocs_.empty())
7110     return;
7111
7112   gold_assert(parameters->doing_static_link());
7113
7114   const off_t offset = this->offset();
7115   const section_size_type oview_size =
7116     convert_to_section_size_type(this->data_size());
7117   unsigned char* const oview = of->get_output_view(offset, oview_size);
7118
7119   Output_segment* tls_segment = this->layout_->tls_segment();
7120   gold_assert(tls_segment != NULL);
7121
7122   // The thread pointer $tp points to the TCB, which is followed by the
7123   // TLS.  So we need to adjust $tp relative addressing by this amount.
7124   Arm_address aligned_tcb_size =
7125     align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7126
7127   for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7128     {
7129       Static_reloc& reloc(this->static_relocs_[i]);
7130
7131       Arm_address value;
7132       if (!reloc.symbol_is_global())
7133         {
7134           Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7135           const Symbol_value<32>* psymval =
7136             reloc.relobj()->local_symbol(reloc.index());
7137
7138           // We are doing static linking.  Issue an error and skip this
7139           // relocation if the symbol is undefined or in a discarded_section.
7140           bool is_ordinary;
7141           unsigned int shndx = psymval->input_shndx(&is_ordinary);
7142           if ((shndx == elfcpp::SHN_UNDEF)
7143               || (is_ordinary
7144                   && shndx != elfcpp::SHN_UNDEF
7145                   && !object->is_section_included(shndx)
7146                   && !this->symbol_table_->is_section_folded(object, shndx)))
7147             {
7148               gold_error(_("undefined or discarded local symbol %u from "
7149                            " object %s in GOT"),
7150                          reloc.index(), reloc.relobj()->name().c_str());
7151               continue;
7152             }
7153
7154           value = psymval->value(object, 0);
7155         }
7156       else
7157         {
7158           const Symbol* gsym = reloc.symbol();
7159           gold_assert(gsym != NULL);
7160           if (gsym->is_forwarder())
7161             gsym = this->symbol_table_->resolve_forwards(gsym);
7162
7163           // We are doing static linking.  Issue an error and skip this
7164           // relocation if the symbol is undefined or in a discarded_section
7165           // unless it is a weakly_undefined symbol.
7166           if ((gsym->is_defined_in_discarded_section()
7167                || gsym->is_undefined())
7168               && !gsym->is_weak_undefined())
7169             {
7170               gold_error(_("undefined or discarded symbol %s in GOT"),
7171                          gsym->name());
7172               continue;
7173             }
7174
7175           if (!gsym->is_weak_undefined())
7176             {
7177               const Sized_symbol<32>* sym =
7178                 static_cast<const Sized_symbol<32>*>(gsym);
7179               value = sym->value();
7180             }
7181           else
7182               value = 0;
7183         }
7184
7185       unsigned got_offset = reloc.got_offset();
7186       gold_assert(got_offset < oview_size);
7187
7188       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7189       Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7190       Valtype x;
7191       switch (reloc.r_type())
7192         {
7193         case elfcpp::R_ARM_TLS_DTPOFF32:
7194           x = value;
7195           break;
7196         case elfcpp::R_ARM_TLS_TPOFF32:
7197           x = value + aligned_tcb_size;
7198           break;
7199         default:
7200           gold_unreachable();
7201         }
7202       elfcpp::Swap<32, big_endian>::writeval(wv, x);
7203     }
7204
7205   of->write_output_view(offset, oview_size, oview);
7206 }
7207
7208 // A class to handle the PLT data.
7209 // This is an abstract base class that handles most of the linker details
7210 // but does not know the actual contents of PLT entries.  The derived
7211 // classes below fill in those details.
7212
7213 template<bool big_endian>
7214 class Output_data_plt_arm : public Output_section_data
7215 {
7216  public:
7217   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7218     Reloc_section;
7219
7220   Output_data_plt_arm(Layout*, uint64_t addralign, Output_data_space*);
7221
7222   // Add an entry to the PLT.
7223   void
7224   add_entry(Symbol* gsym);
7225
7226   // Return the .rel.plt section data.
7227   const Reloc_section*
7228   rel_plt() const
7229   { return this->rel_; }
7230
7231   // Return the number of PLT entries.
7232   unsigned int
7233   entry_count() const
7234   { return this->count_; }
7235
7236   // Return the offset of the first non-reserved PLT entry.
7237   unsigned int
7238   first_plt_entry_offset() const
7239   { return this->do_first_plt_entry_offset(); }
7240
7241   // Return the size of a PLT entry.
7242   unsigned int
7243   get_plt_entry_size() const
7244   { return this->do_get_plt_entry_size(); }
7245
7246  protected:
7247   // Fill in the first PLT entry.
7248   void
7249   fill_first_plt_entry(unsigned char* pov,
7250                        Arm_address got_address,
7251                        Arm_address plt_address)
7252   { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
7253
7254   void
7255   fill_plt_entry(unsigned char* pov,
7256                  Arm_address got_address,
7257                  Arm_address plt_address,
7258                  unsigned int got_offset,
7259                  unsigned int plt_offset)
7260   { do_fill_plt_entry(pov, got_address, plt_address, got_offset, plt_offset); }
7261
7262   virtual unsigned int
7263   do_first_plt_entry_offset() const = 0;
7264
7265   virtual unsigned int
7266   do_get_plt_entry_size() const = 0;
7267
7268   virtual void
7269   do_fill_first_plt_entry(unsigned char* pov,
7270                           Arm_address got_address,
7271                           Arm_address plt_address) = 0;
7272
7273   virtual void
7274   do_fill_plt_entry(unsigned char* pov,
7275                     Arm_address got_address,
7276                     Arm_address plt_address,
7277                     unsigned int got_offset,
7278                     unsigned int plt_offset) = 0;
7279
7280   void
7281   do_adjust_output_section(Output_section* os);
7282
7283   // Write to a map file.
7284   void
7285   do_print_to_mapfile(Mapfile* mapfile) const
7286   { mapfile->print_output_data(this, _("** PLT")); }
7287
7288  private:
7289   // Set the final size.
7290   void
7291   set_final_data_size()
7292   {
7293     this->set_data_size(this->first_plt_entry_offset()
7294                         + this->count_ * this->get_plt_entry_size());
7295   }
7296
7297   // Write out the PLT data.
7298   void
7299   do_write(Output_file*);
7300
7301   // The reloc section.
7302   Reloc_section* rel_;
7303   // The .got.plt section.
7304   Output_data_space* got_plt_;
7305   // The number of PLT entries.
7306   unsigned int count_;
7307 };
7308
7309 // Create the PLT section.  The ordinary .got section is an argument,
7310 // since we need to refer to the start.  We also create our own .got
7311 // section just for PLT entries.
7312
7313 template<bool big_endian>
7314 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7315                                                      uint64_t addralign,
7316                                                      Output_data_space* got_plt)
7317   : Output_section_data(addralign), got_plt_(got_plt), count_(0)
7318 {
7319   this->rel_ = new Reloc_section(false);
7320   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7321                                   elfcpp::SHF_ALLOC, this->rel_,
7322                                   ORDER_DYNAMIC_PLT_RELOCS, false);
7323 }
7324
7325 template<bool big_endian>
7326 void
7327 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7328 {
7329   os->set_entsize(0);
7330 }
7331
7332 // Add an entry to the PLT.
7333
7334 template<bool big_endian>
7335 void
7336 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7337 {
7338   gold_assert(!gsym->has_plt_offset());
7339
7340   // Note that when setting the PLT offset we skip the initial
7341   // reserved PLT entry.
7342   gsym->set_plt_offset((this->count_) * this->get_plt_entry_size()
7343                        + this->first_plt_entry_offset());
7344
7345   ++this->count_;
7346
7347   section_offset_type got_offset = this->got_plt_->current_data_size();
7348
7349   // Every PLT entry needs a GOT entry which points back to the PLT
7350   // entry (this will be changed by the dynamic linker, normally
7351   // lazily when the function is called).
7352   this->got_plt_->set_current_data_size(got_offset + 4);
7353
7354   // Every PLT entry needs a reloc.
7355   gsym->set_needs_dynsym_entry();
7356   this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7357                          got_offset);
7358
7359   // Note that we don't need to save the symbol.  The contents of the
7360   // PLT are independent of which symbols are used.  The symbols only
7361   // appear in the relocations.
7362 }
7363
7364 template<bool big_endian>
7365 class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
7366 {
7367  public:
7368   Output_data_plt_arm_standard(Layout* layout, Output_data_space* got_plt)
7369     : Output_data_plt_arm<big_endian>(layout, 4, got_plt)
7370   { }
7371
7372  protected:
7373   // Return the offset of the first non-reserved PLT entry.
7374   virtual unsigned int
7375   do_first_plt_entry_offset() const
7376   { return sizeof(first_plt_entry); }
7377
7378   // Return the size of a PLT entry.
7379   virtual unsigned int
7380   do_get_plt_entry_size() const
7381   { return sizeof(plt_entry); }
7382
7383   virtual void
7384   do_fill_first_plt_entry(unsigned char* pov,
7385                           Arm_address got_address,
7386                           Arm_address plt_address);
7387
7388   virtual void
7389   do_fill_plt_entry(unsigned char* pov,
7390                     Arm_address got_address,
7391                     Arm_address plt_address,
7392                     unsigned int got_offset,
7393                     unsigned int plt_offset);
7394
7395  private:
7396   // Template for the first PLT entry.
7397   static const uint32_t first_plt_entry[5];
7398
7399   // Template for subsequent PLT entries.
7400   static const uint32_t plt_entry[3];
7401 };
7402
7403 // ARM PLTs.
7404 // FIXME:  This is not very flexible.  Right now this has only been tested
7405 // on armv5te.  If we are to support additional architecture features like
7406 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7407
7408 // The first entry in the PLT.
7409 template<bool big_endian>
7410 const uint32_t Output_data_plt_arm_standard<big_endian>::first_plt_entry[5] =
7411 {
7412   0xe52de004,   // str   lr, [sp, #-4]!
7413   0xe59fe004,   // ldr   lr, [pc, #4]
7414   0xe08fe00e,   // add   lr, pc, lr
7415   0xe5bef008,   // ldr   pc, [lr, #8]!
7416   0x00000000,   // &GOT[0] - .
7417 };
7418
7419 template<bool big_endian>
7420 void
7421 Output_data_plt_arm_standard<big_endian>::do_fill_first_plt_entry(
7422     unsigned char* pov,
7423     Arm_address got_address,
7424     Arm_address plt_address)
7425 {
7426   // Write first PLT entry.  All but the last word are constants.
7427   const size_t num_first_plt_words = (sizeof(first_plt_entry)
7428                                       / sizeof(plt_entry[0]));
7429   for (size_t i = 0; i < num_first_plt_words - 1; i++)
7430     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7431   // Last word in first PLT entry is &GOT[0] - .
7432   elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7433                                          got_address - (plt_address + 16));
7434 }
7435
7436 // Subsequent entries in the PLT.
7437
7438 template<bool big_endian>
7439 const uint32_t Output_data_plt_arm_standard<big_endian>::plt_entry[3] =
7440 {
7441   0xe28fc600,   // add   ip, pc, #0xNN00000
7442   0xe28cca00,   // add   ip, ip, #0xNN000
7443   0xe5bcf000,   // ldr   pc, [ip, #0xNNN]!
7444 };
7445
7446 template<bool big_endian>
7447 void
7448 Output_data_plt_arm_standard<big_endian>::do_fill_plt_entry(
7449     unsigned char* pov,
7450     Arm_address got_address,
7451     Arm_address plt_address,
7452     unsigned int got_offset,
7453     unsigned int plt_offset)
7454 {
7455   int32_t offset = ((got_address + got_offset)
7456                     - (plt_address + plt_offset + 8));
7457
7458   gold_assert(offset >= 0 && offset < 0x0fffffff);
7459   uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7460   elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7461   uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7462   elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7463   uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7464   elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7465 }
7466
7467 // Write out the PLT.  This uses the hand-coded instructions above,
7468 // and adjusts them as needed.  This is all specified by the arm ELF
7469 // Processor Supplement.
7470
7471 template<bool big_endian>
7472 void
7473 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7474 {
7475   const off_t offset = this->offset();
7476   const section_size_type oview_size =
7477     convert_to_section_size_type(this->data_size());
7478   unsigned char* const oview = of->get_output_view(offset, oview_size);
7479
7480   const off_t got_file_offset = this->got_plt_->offset();
7481   const section_size_type got_size =
7482     convert_to_section_size_type(this->got_plt_->data_size());
7483   unsigned char* const got_view = of->get_output_view(got_file_offset,
7484                                                       got_size);
7485   unsigned char* pov = oview;
7486
7487   Arm_address plt_address = this->address();
7488   Arm_address got_address = this->got_plt_->address();
7489
7490   // Write first PLT entry.
7491   this->fill_first_plt_entry(pov, got_address, plt_address);
7492   pov += this->first_plt_entry_offset();
7493
7494   unsigned char* got_pov = got_view;
7495
7496   memset(got_pov, 0, 12);
7497   got_pov += 12;
7498
7499   unsigned int plt_offset = this->first_plt_entry_offset();
7500   unsigned int got_offset = 12;
7501   const unsigned int count = this->count_;
7502   for (unsigned int i = 0;
7503        i < count;
7504        ++i,
7505          pov += this->get_plt_entry_size(),
7506          got_pov += 4,
7507          plt_offset += this->get_plt_entry_size(),
7508          got_offset += 4)
7509     {
7510       // Set and adjust the PLT entry itself.
7511       this->fill_plt_entry(pov, got_address, plt_address,
7512                            got_offset, plt_offset);
7513
7514       // Set the entry in the GOT.
7515       elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7516     }
7517
7518   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7519   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7520
7521   of->write_output_view(offset, oview_size, oview);
7522   of->write_output_view(got_file_offset, got_size, got_view);
7523 }
7524
7525 // Create a PLT entry for a global symbol.
7526
7527 template<bool big_endian>
7528 void
7529 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7530                                        Symbol* gsym)
7531 {
7532   if (gsym->has_plt_offset())
7533     return;
7534
7535   if (this->plt_ == NULL)
7536     {
7537       // Create the GOT sections first.
7538       this->got_section(symtab, layout);
7539
7540       this->plt_ = this->make_data_plt(layout, this->got_plt_);
7541
7542       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7543                                       (elfcpp::SHF_ALLOC
7544                                        | elfcpp::SHF_EXECINSTR),
7545                                       this->plt_, ORDER_PLT, false);
7546     }
7547   this->plt_->add_entry(gsym);
7548 }
7549
7550 // Return the number of entries in the PLT.
7551
7552 template<bool big_endian>
7553 unsigned int
7554 Target_arm<big_endian>::plt_entry_count() const
7555 {
7556   if (this->plt_ == NULL)
7557     return 0;
7558   return this->plt_->entry_count();
7559 }
7560
7561 // Return the offset of the first non-reserved PLT entry.
7562
7563 template<bool big_endian>
7564 unsigned int
7565 Target_arm<big_endian>::first_plt_entry_offset() const
7566 {
7567   return this->plt_->first_plt_entry_offset();
7568 }
7569
7570 // Return the size of each PLT entry.
7571
7572 template<bool big_endian>
7573 unsigned int
7574 Target_arm<big_endian>::plt_entry_size() const
7575 {
7576   return this->plt_->get_plt_entry_size();
7577 }
7578
7579 // Get the section to use for TLS_DESC relocations.
7580
7581 template<bool big_endian>
7582 typename Target_arm<big_endian>::Reloc_section*
7583 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7584 {
7585   return this->plt_section()->rel_tls_desc(layout);
7586 }
7587
7588 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7589
7590 template<bool big_endian>
7591 void
7592 Target_arm<big_endian>::define_tls_base_symbol(
7593     Symbol_table* symtab,
7594     Layout* layout)
7595 {
7596   if (this->tls_base_symbol_defined_)
7597     return;
7598
7599   Output_segment* tls_segment = layout->tls_segment();
7600   if (tls_segment != NULL)
7601     {
7602       bool is_exec = parameters->options().output_is_executable();
7603       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7604                                        Symbol_table::PREDEFINED,
7605                                        tls_segment, 0, 0,
7606                                        elfcpp::STT_TLS,
7607                                        elfcpp::STB_LOCAL,
7608                                        elfcpp::STV_HIDDEN, 0,
7609                                        (is_exec
7610                                         ? Symbol::SEGMENT_END
7611                                         : Symbol::SEGMENT_START),
7612                                        true);
7613     }
7614   this->tls_base_symbol_defined_ = true;
7615 }
7616
7617 // Create a GOT entry for the TLS module index.
7618
7619 template<bool big_endian>
7620 unsigned int
7621 Target_arm<big_endian>::got_mod_index_entry(
7622     Symbol_table* symtab,
7623     Layout* layout,
7624     Sized_relobj_file<32, big_endian>* object)
7625 {
7626   if (this->got_mod_index_offset_ == -1U)
7627     {
7628       gold_assert(symtab != NULL && layout != NULL && object != NULL);
7629       Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7630       unsigned int got_offset;
7631       if (!parameters->doing_static_link())
7632         {
7633           got_offset = got->add_constant(0);
7634           Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7635           rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7636                              got_offset);
7637         }
7638       else
7639         {
7640           // We are doing a static link.  Just mark it as belong to module 1,
7641           // the executable.
7642           got_offset = got->add_constant(1);
7643         }
7644
7645       got->add_constant(0);
7646       this->got_mod_index_offset_ = got_offset;
7647     }
7648   return this->got_mod_index_offset_;
7649 }
7650
7651 // Optimize the TLS relocation type based on what we know about the
7652 // symbol.  IS_FINAL is true if the final address of this symbol is
7653 // known at link time.
7654
7655 template<bool big_endian>
7656 tls::Tls_optimization
7657 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7658 {
7659   // FIXME: Currently we do not do any TLS optimization.
7660   return tls::TLSOPT_NONE;
7661 }
7662
7663 // Get the Reference_flags for a particular relocation.
7664
7665 template<bool big_endian>
7666 int
7667 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
7668 {
7669   switch (r_type)
7670     {
7671     case elfcpp::R_ARM_NONE:
7672     case elfcpp::R_ARM_V4BX:
7673     case elfcpp::R_ARM_GNU_VTENTRY:
7674     case elfcpp::R_ARM_GNU_VTINHERIT:
7675       // No symbol reference.
7676       return 0;
7677
7678     case elfcpp::R_ARM_ABS32:
7679     case elfcpp::R_ARM_ABS16:
7680     case elfcpp::R_ARM_ABS12:
7681     case elfcpp::R_ARM_THM_ABS5:
7682     case elfcpp::R_ARM_ABS8:
7683     case elfcpp::R_ARM_BASE_ABS:
7684     case elfcpp::R_ARM_MOVW_ABS_NC:
7685     case elfcpp::R_ARM_MOVT_ABS:
7686     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7687     case elfcpp::R_ARM_THM_MOVT_ABS:
7688     case elfcpp::R_ARM_ABS32_NOI:
7689       return Symbol::ABSOLUTE_REF;
7690
7691     case elfcpp::R_ARM_REL32:
7692     case elfcpp::R_ARM_LDR_PC_G0:
7693     case elfcpp::R_ARM_SBREL32:
7694     case elfcpp::R_ARM_THM_PC8:
7695     case elfcpp::R_ARM_BASE_PREL:
7696     case elfcpp::R_ARM_MOVW_PREL_NC:
7697     case elfcpp::R_ARM_MOVT_PREL:
7698     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7699     case elfcpp::R_ARM_THM_MOVT_PREL:
7700     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7701     case elfcpp::R_ARM_THM_PC12:
7702     case elfcpp::R_ARM_REL32_NOI:
7703     case elfcpp::R_ARM_ALU_PC_G0_NC:
7704     case elfcpp::R_ARM_ALU_PC_G0:
7705     case elfcpp::R_ARM_ALU_PC_G1_NC:
7706     case elfcpp::R_ARM_ALU_PC_G1:
7707     case elfcpp::R_ARM_ALU_PC_G2:
7708     case elfcpp::R_ARM_LDR_PC_G1:
7709     case elfcpp::R_ARM_LDR_PC_G2:
7710     case elfcpp::R_ARM_LDRS_PC_G0:
7711     case elfcpp::R_ARM_LDRS_PC_G1:
7712     case elfcpp::R_ARM_LDRS_PC_G2:
7713     case elfcpp::R_ARM_LDC_PC_G0:
7714     case elfcpp::R_ARM_LDC_PC_G1:
7715     case elfcpp::R_ARM_LDC_PC_G2:
7716     case elfcpp::R_ARM_ALU_SB_G0_NC:
7717     case elfcpp::R_ARM_ALU_SB_G0:
7718     case elfcpp::R_ARM_ALU_SB_G1_NC:
7719     case elfcpp::R_ARM_ALU_SB_G1:
7720     case elfcpp::R_ARM_ALU_SB_G2:
7721     case elfcpp::R_ARM_LDR_SB_G0:
7722     case elfcpp::R_ARM_LDR_SB_G1:
7723     case elfcpp::R_ARM_LDR_SB_G2:
7724     case elfcpp::R_ARM_LDRS_SB_G0:
7725     case elfcpp::R_ARM_LDRS_SB_G1:
7726     case elfcpp::R_ARM_LDRS_SB_G2:
7727     case elfcpp::R_ARM_LDC_SB_G0:
7728     case elfcpp::R_ARM_LDC_SB_G1:
7729     case elfcpp::R_ARM_LDC_SB_G2:
7730     case elfcpp::R_ARM_MOVW_BREL_NC:
7731     case elfcpp::R_ARM_MOVT_BREL:
7732     case elfcpp::R_ARM_MOVW_BREL:
7733     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7734     case elfcpp::R_ARM_THM_MOVT_BREL:
7735     case elfcpp::R_ARM_THM_MOVW_BREL:
7736     case elfcpp::R_ARM_GOTOFF32:
7737     case elfcpp::R_ARM_GOTOFF12:
7738     case elfcpp::R_ARM_SBREL31:
7739       return Symbol::RELATIVE_REF;
7740
7741     case elfcpp::R_ARM_PLT32:
7742     case elfcpp::R_ARM_CALL:
7743     case elfcpp::R_ARM_JUMP24:
7744     case elfcpp::R_ARM_THM_CALL:
7745     case elfcpp::R_ARM_THM_JUMP24:
7746     case elfcpp::R_ARM_THM_JUMP19:
7747     case elfcpp::R_ARM_THM_JUMP6:
7748     case elfcpp::R_ARM_THM_JUMP11:
7749     case elfcpp::R_ARM_THM_JUMP8:
7750     // R_ARM_PREL31 is not used to relocate call/jump instructions but
7751     // in unwind tables. It may point to functions via PLTs.
7752     // So we treat it like call/jump relocations above.
7753     case elfcpp::R_ARM_PREL31:
7754       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
7755
7756     case elfcpp::R_ARM_GOT_BREL:
7757     case elfcpp::R_ARM_GOT_ABS:
7758     case elfcpp::R_ARM_GOT_PREL:
7759       // Absolute in GOT.
7760       return Symbol::ABSOLUTE_REF;
7761
7762     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
7763     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
7764     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
7765     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
7766     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
7767       return Symbol::TLS_REF;
7768
7769     case elfcpp::R_ARM_TARGET1:
7770     case elfcpp::R_ARM_TARGET2:
7771     case elfcpp::R_ARM_COPY:
7772     case elfcpp::R_ARM_GLOB_DAT:
7773     case elfcpp::R_ARM_JUMP_SLOT:
7774     case elfcpp::R_ARM_RELATIVE:
7775     case elfcpp::R_ARM_PC24:
7776     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7777     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7778     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7779     default:
7780       // Not expected.  We will give an error later.
7781       return 0;
7782     }
7783 }
7784
7785 // Report an unsupported relocation against a local symbol.
7786
7787 template<bool big_endian>
7788 void
7789 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7790     Sized_relobj_file<32, big_endian>* object,
7791     unsigned int r_type)
7792 {
7793   gold_error(_("%s: unsupported reloc %u against local symbol"),
7794              object->name().c_str(), r_type);
7795 }
7796
7797 // We are about to emit a dynamic relocation of type R_TYPE.  If the
7798 // dynamic linker does not support it, issue an error.  The GNU linker
7799 // only issues a non-PIC error for an allocated read-only section.
7800 // Here we know the section is allocated, but we don't know that it is
7801 // read-only.  But we check for all the relocation types which the
7802 // glibc dynamic linker supports, so it seems appropriate to issue an
7803 // error even if the section is not read-only.
7804
7805 template<bool big_endian>
7806 void
7807 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7808                                             unsigned int r_type)
7809 {
7810   switch (r_type)
7811     {
7812     // These are the relocation types supported by glibc for ARM.
7813     case elfcpp::R_ARM_RELATIVE:
7814     case elfcpp::R_ARM_COPY:
7815     case elfcpp::R_ARM_GLOB_DAT:
7816     case elfcpp::R_ARM_JUMP_SLOT:
7817     case elfcpp::R_ARM_ABS32:
7818     case elfcpp::R_ARM_ABS32_NOI:
7819     case elfcpp::R_ARM_PC24:
7820     // FIXME: The following 3 types are not supported by Android's dynamic
7821     // linker.
7822     case elfcpp::R_ARM_TLS_DTPMOD32:
7823     case elfcpp::R_ARM_TLS_DTPOFF32:
7824     case elfcpp::R_ARM_TLS_TPOFF32:
7825       return;
7826
7827     default:
7828       {
7829         // This prevents us from issuing more than one error per reloc
7830         // section.  But we can still wind up issuing more than one
7831         // error per object file.
7832         if (this->issued_non_pic_error_)
7833           return;
7834         const Arm_reloc_property* reloc_property =
7835           arm_reloc_property_table->get_reloc_property(r_type);
7836         gold_assert(reloc_property != NULL);
7837         object->error(_("requires unsupported dynamic reloc %s; "
7838                       "recompile with -fPIC"),
7839                       reloc_property->name().c_str());
7840         this->issued_non_pic_error_ = true;
7841         return;
7842       }
7843
7844     case elfcpp::R_ARM_NONE:
7845       gold_unreachable();
7846     }
7847 }
7848
7849 // Scan a relocation for a local symbol.
7850 // FIXME: This only handles a subset of relocation types used by Android
7851 // on ARM v5te devices.
7852
7853 template<bool big_endian>
7854 inline void
7855 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7856                                     Layout* layout,
7857                                     Target_arm* target,
7858                                     Sized_relobj_file<32, big_endian>* object,
7859                                     unsigned int data_shndx,
7860                                     Output_section* output_section,
7861                                     const elfcpp::Rel<32, big_endian>& reloc,
7862                                     unsigned int r_type,
7863                                     const elfcpp::Sym<32, big_endian>& lsym)
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, 0);
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>(
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 // Relocate a section during a relocatable link.
9595
9596 template<bool big_endian>
9597 void
9598 Target_arm<big_endian>::relocate_for_relocatable(
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     off_t 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_for_relocatable<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     off_t 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) const
10018 {
10019   gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
10020
10021   elfcpp::Ehdr<32, big_endian> ehdr(view);
10022   unsigned char e_ident[elfcpp::EI_NIDENT];
10023   memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
10024
10025   if (elfcpp::arm_eabi_version(this->processor_specific_flags())
10026       == elfcpp::EF_ARM_EABI_UNKNOWN)
10027     e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
10028   else
10029     e_ident[elfcpp::EI_OSABI] = 0;
10030   e_ident[elfcpp::EI_ABIVERSION] = 0;
10031
10032   // FIXME: Do EF_ARM_BE8 adjustment.
10033
10034   elfcpp::Ehdr_write<32, big_endian> oehdr(view);
10035   oehdr.put_e_ident(e_ident);
10036 }
10037
10038 // do_make_elf_object to override the same function in the base class.
10039 // We need to use a target-specific sub-class of
10040 // Sized_relobj_file<32, big_endian> to store ARM specific information.
10041 // Hence we need to have our own ELF object creation.
10042
10043 template<bool big_endian>
10044 Object*
10045 Target_arm<big_endian>::do_make_elf_object(
10046     const std::string& name,
10047     Input_file* input_file,
10048     off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
10049 {
10050   int et = ehdr.get_e_type();
10051   // ET_EXEC files are valid input for --just-symbols/-R,
10052   // and we treat them as relocatable objects.
10053   if (et == elfcpp::ET_REL
10054       || (et == elfcpp::ET_EXEC && input_file->just_symbols()))
10055     {
10056       Arm_relobj<big_endian>* obj =
10057         new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
10058       obj->setup();
10059       return obj;
10060     }
10061   else if (et == elfcpp::ET_DYN)
10062     {
10063       Sized_dynobj<32, big_endian>* obj =
10064         new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
10065       obj->setup();
10066       return obj;
10067     }
10068   else
10069     {
10070       gold_error(_("%s: unsupported ELF file type %d"),
10071                  name.c_str(), et);
10072       return NULL;
10073     }
10074 }
10075
10076 // Read the architecture from the Tag_also_compatible_with attribute, if any.
10077 // Returns -1 if no architecture could be read.
10078 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
10079
10080 template<bool big_endian>
10081 int
10082 Target_arm<big_endian>::get_secondary_compatible_arch(
10083     const Attributes_section_data* pasd)
10084 {
10085   const Object_attribute* known_attributes =
10086     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10087
10088   // Note: the tag and its argument below are uleb128 values, though
10089   // currently-defined values fit in one byte for each.
10090   const std::string& sv =
10091     known_attributes[elfcpp::Tag_also_compatible_with].string_value();
10092   if (sv.size() == 2
10093       && sv.data()[0] == elfcpp::Tag_CPU_arch
10094       && (sv.data()[1] & 128) != 128)
10095    return sv.data()[1];
10096
10097   // This tag is "safely ignorable", so don't complain if it looks funny.
10098   return -1;
10099 }
10100
10101 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10102 // The tag is removed if ARCH is -1.
10103 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10104
10105 template<bool big_endian>
10106 void
10107 Target_arm<big_endian>::set_secondary_compatible_arch(
10108     Attributes_section_data* pasd,
10109     int arch)
10110 {
10111   Object_attribute* known_attributes =
10112     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10113
10114   if (arch == -1)
10115     {
10116       known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10117       return;
10118     }
10119
10120   // Note: the tag and its argument below are uleb128 values, though
10121   // currently-defined values fit in one byte for each.
10122   char sv[3];
10123   sv[0] = elfcpp::Tag_CPU_arch;
10124   gold_assert(arch != 0);
10125   sv[1] = arch;
10126   sv[2] = '\0';
10127
10128   known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10129 }
10130
10131 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10132 // into account.
10133 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10134
10135 template<bool big_endian>
10136 int
10137 Target_arm<big_endian>::tag_cpu_arch_combine(
10138     const char* name,
10139     int oldtag,
10140     int* secondary_compat_out,
10141     int newtag,
10142     int secondary_compat)
10143 {
10144 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10145   static const int v6t2[] =
10146     {
10147       T(V6T2),   // PRE_V4.
10148       T(V6T2),   // V4.
10149       T(V6T2),   // V4T.
10150       T(V6T2),   // V5T.
10151       T(V6T2),   // V5TE.
10152       T(V6T2),   // V5TEJ.
10153       T(V6T2),   // V6.
10154       T(V7),     // V6KZ.
10155       T(V6T2)    // V6T2.
10156     };
10157   static const int v6k[] =
10158     {
10159       T(V6K),    // PRE_V4.
10160       T(V6K),    // V4.
10161       T(V6K),    // V4T.
10162       T(V6K),    // V5T.
10163       T(V6K),    // V5TE.
10164       T(V6K),    // V5TEJ.
10165       T(V6K),    // V6.
10166       T(V6KZ),   // V6KZ.
10167       T(V7),     // V6T2.
10168       T(V6K)     // V6K.
10169     };
10170   static const int v7[] =
10171     {
10172       T(V7),     // PRE_V4.
10173       T(V7),     // V4.
10174       T(V7),     // V4T.
10175       T(V7),     // V5T.
10176       T(V7),     // V5TE.
10177       T(V7),     // V5TEJ.
10178       T(V7),     // V6.
10179       T(V7),     // V6KZ.
10180       T(V7),     // V6T2.
10181       T(V7),     // V6K.
10182       T(V7)      // V7.
10183     };
10184   static const int v6_m[] =
10185     {
10186       -1,        // PRE_V4.
10187       -1,        // V4.
10188       T(V6K),    // V4T.
10189       T(V6K),    // V5T.
10190       T(V6K),    // V5TE.
10191       T(V6K),    // V5TEJ.
10192       T(V6K),    // V6.
10193       T(V6KZ),   // V6KZ.
10194       T(V7),     // V6T2.
10195       T(V6K),    // V6K.
10196       T(V7),     // V7.
10197       T(V6_M)    // V6_M.
10198     };
10199   static const int v6s_m[] =
10200     {
10201       -1,        // PRE_V4.
10202       -1,        // V4.
10203       T(V6K),    // V4T.
10204       T(V6K),    // V5T.
10205       T(V6K),    // V5TE.
10206       T(V6K),    // V5TEJ.
10207       T(V6K),    // V6.
10208       T(V6KZ),   // V6KZ.
10209       T(V7),     // V6T2.
10210       T(V6K),    // V6K.
10211       T(V7),     // V7.
10212       T(V6S_M),  // V6_M.
10213       T(V6S_M)   // V6S_M.
10214     };
10215   static const int v7e_m[] =
10216     {
10217       -1,       // PRE_V4.
10218       -1,       // V4.
10219       T(V7E_M), // V4T.
10220       T(V7E_M), // V5T.
10221       T(V7E_M), // V5TE.
10222       T(V7E_M), // V5TEJ.
10223       T(V7E_M), // V6.
10224       T(V7E_M), // V6KZ.
10225       T(V7E_M), // V6T2.
10226       T(V7E_M), // V6K.
10227       T(V7E_M), // V7.
10228       T(V7E_M), // V6_M.
10229       T(V7E_M), // V6S_M.
10230       T(V7E_M)  // V7E_M.
10231     };
10232   static const int v4t_plus_v6_m[] =
10233     {
10234       -1,               // PRE_V4.
10235       -1,               // V4.
10236       T(V4T),           // V4T.
10237       T(V5T),           // V5T.
10238       T(V5TE),          // V5TE.
10239       T(V5TEJ),         // V5TEJ.
10240       T(V6),            // V6.
10241       T(V6KZ),          // V6KZ.
10242       T(V6T2),          // V6T2.
10243       T(V6K),           // V6K.
10244       T(V7),            // V7.
10245       T(V6_M),          // V6_M.
10246       T(V6S_M),         // V6S_M.
10247       T(V7E_M),         // V7E_M.
10248       T(V4T_PLUS_V6_M)  // V4T plus V6_M.
10249     };
10250   static const int* comb[] =
10251     {
10252       v6t2,
10253       v6k,
10254       v7,
10255       v6_m,
10256       v6s_m,
10257       v7e_m,
10258       // Pseudo-architecture.
10259       v4t_plus_v6_m
10260     };
10261
10262   // Check we've not got a higher architecture than we know about.
10263
10264   if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
10265     {
10266       gold_error(_("%s: unknown CPU architecture"), name);
10267       return -1;
10268     }
10269
10270   // Override old tag if we have a Tag_also_compatible_with on the output.
10271
10272   if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10273       || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10274     oldtag = T(V4T_PLUS_V6_M);
10275
10276   // And override the new tag if we have a Tag_also_compatible_with on the
10277   // input.
10278
10279   if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10280       || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10281     newtag = T(V4T_PLUS_V6_M);
10282
10283   // Architectures before V6KZ add features monotonically.
10284   int tagh = std::max(oldtag, newtag);
10285   if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10286     return tagh;
10287
10288   int tagl = std::min(oldtag, newtag);
10289   int result = comb[tagh - T(V6T2)][tagl];
10290
10291   // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10292   // as the canonical version.
10293   if (result == T(V4T_PLUS_V6_M))
10294     {
10295       result = T(V4T);
10296       *secondary_compat_out = T(V6_M);
10297     }
10298   else
10299     *secondary_compat_out = -1;
10300
10301   if (result == -1)
10302     {
10303       gold_error(_("%s: conflicting CPU architectures %d/%d"),
10304                  name, oldtag, newtag);
10305       return -1;
10306     }
10307
10308   return result;
10309 #undef T
10310 }
10311
10312 // Helper to print AEABI enum tag value.
10313
10314 template<bool big_endian>
10315 std::string
10316 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10317 {
10318   static const char* aeabi_enum_names[] =
10319     { "", "variable-size", "32-bit", "" };
10320   const size_t aeabi_enum_names_size =
10321     sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10322
10323   if (value < aeabi_enum_names_size)
10324     return std::string(aeabi_enum_names[value]);
10325   else
10326     {
10327       char buffer[100];
10328       sprintf(buffer, "<unknown value %u>", value);
10329       return std::string(buffer);
10330     }
10331 }
10332
10333 // Return the string value to store in TAG_CPU_name.
10334
10335 template<bool big_endian>
10336 std::string
10337 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10338 {
10339   static const char* name_table[] = {
10340     // These aren't real CPU names, but we can't guess
10341     // that from the architecture version alone.
10342    "Pre v4",
10343    "ARM v4",
10344    "ARM v4T",
10345    "ARM v5T",
10346    "ARM v5TE",
10347    "ARM v5TEJ",
10348    "ARM v6",
10349    "ARM v6KZ",
10350    "ARM v6T2",
10351    "ARM v6K",
10352    "ARM v7",
10353    "ARM v6-M",
10354    "ARM v6S-M",
10355    "ARM v7E-M"
10356  };
10357  const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10358
10359   if (value < name_table_size)
10360     return std::string(name_table[value]);
10361   else
10362     {
10363       char buffer[100];
10364       sprintf(buffer, "<unknown CPU value %u>", value);
10365       return std::string(buffer);
10366     }
10367 }
10368
10369 // Merge object attributes from input file called NAME with those of the
10370 // output.  The input object attributes are in the object pointed by PASD.
10371
10372 template<bool big_endian>
10373 void
10374 Target_arm<big_endian>::merge_object_attributes(
10375     const char* name,
10376     const Attributes_section_data* pasd)
10377 {
10378   // Return if there is no attributes section data.
10379   if (pasd == NULL)
10380     return;
10381
10382   // If output has no object attributes, just copy.
10383   const int vendor = Object_attribute::OBJ_ATTR_PROC;
10384   if (this->attributes_section_data_ == NULL)
10385     {
10386       this->attributes_section_data_ = new Attributes_section_data(*pasd);
10387       Object_attribute* out_attr =
10388         this->attributes_section_data_->known_attributes(vendor);
10389
10390       // We do not output objects with Tag_MPextension_use_legacy - we move
10391       //  the attribute's value to Tag_MPextension_use.  */
10392       if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10393         {
10394           if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10395               && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10396                 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10397             {
10398               gold_error(_("%s has both the current and legacy "
10399                            "Tag_MPextension_use attributes"),
10400                          name);
10401             }
10402
10403           out_attr[elfcpp::Tag_MPextension_use] =
10404             out_attr[elfcpp::Tag_MPextension_use_legacy];
10405           out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10406           out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10407         }
10408
10409       return;
10410     }
10411
10412   const Object_attribute* in_attr = pasd->known_attributes(vendor);
10413   Object_attribute* out_attr =
10414     this->attributes_section_data_->known_attributes(vendor);
10415
10416   // This needs to happen before Tag_ABI_FP_number_model is merged.  */
10417   if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10418       != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
10419     {
10420       // Ignore mismatches if the object doesn't use floating point.  */
10421       if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
10422         out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10423             in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10424       else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
10425                && parameters->options().warn_mismatch())
10426         gold_error(_("%s uses VFP register arguments, output does not"),
10427                    name);
10428     }
10429
10430   for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10431     {
10432       // Merge this attribute with existing attributes.
10433       switch (i)
10434         {
10435         case elfcpp::Tag_CPU_raw_name:
10436         case elfcpp::Tag_CPU_name:
10437           // These are merged after Tag_CPU_arch.
10438           break;
10439
10440         case elfcpp::Tag_ABI_optimization_goals:
10441         case elfcpp::Tag_ABI_FP_optimization_goals:
10442           // Use the first value seen.
10443           break;
10444
10445         case elfcpp::Tag_CPU_arch:
10446           {
10447             unsigned int saved_out_attr = out_attr->int_value();
10448             // Merge Tag_CPU_arch and Tag_also_compatible_with.
10449             int secondary_compat =
10450               this->get_secondary_compatible_arch(pasd);
10451             int secondary_compat_out =
10452               this->get_secondary_compatible_arch(
10453                   this->attributes_section_data_);
10454             out_attr[i].set_int_value(
10455                 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10456                                      &secondary_compat_out,
10457                                      in_attr[i].int_value(),
10458                                      secondary_compat));
10459             this->set_secondary_compatible_arch(this->attributes_section_data_,
10460                                                 secondary_compat_out);
10461
10462             // Merge Tag_CPU_name and Tag_CPU_raw_name.
10463             if (out_attr[i].int_value() == saved_out_attr)
10464               ; // Leave the names alone.
10465             else if (out_attr[i].int_value() == in_attr[i].int_value())
10466               {
10467                 // The output architecture has been changed to match the
10468                 // input architecture.  Use the input names.
10469                 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10470                     in_attr[elfcpp::Tag_CPU_name].string_value());
10471                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10472                     in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10473               }
10474             else
10475               {
10476                 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10477                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10478               }
10479
10480             // If we still don't have a value for Tag_CPU_name,
10481             // make one up now.  Tag_CPU_raw_name remains blank.
10482             if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10483               {
10484                 const std::string cpu_name =
10485                   this->tag_cpu_name_value(out_attr[i].int_value());
10486                 // FIXME:  If we see an unknown CPU, this will be set
10487                 // to "<unknown CPU n>", where n is the attribute value.
10488                 // This is different from BFD, which leaves the name alone.
10489                 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10490               }
10491           }
10492           break;
10493
10494         case elfcpp::Tag_ARM_ISA_use:
10495         case elfcpp::Tag_THUMB_ISA_use:
10496         case elfcpp::Tag_WMMX_arch:
10497         case elfcpp::Tag_Advanced_SIMD_arch:
10498           // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10499         case elfcpp::Tag_ABI_FP_rounding:
10500         case elfcpp::Tag_ABI_FP_exceptions:
10501         case elfcpp::Tag_ABI_FP_user_exceptions:
10502         case elfcpp::Tag_ABI_FP_number_model:
10503         case elfcpp::Tag_VFP_HP_extension:
10504         case elfcpp::Tag_CPU_unaligned_access:
10505         case elfcpp::Tag_T2EE_use:
10506         case elfcpp::Tag_Virtualization_use:
10507         case elfcpp::Tag_MPextension_use:
10508           // Use the largest value specified.
10509           if (in_attr[i].int_value() > out_attr[i].int_value())
10510             out_attr[i].set_int_value(in_attr[i].int_value());
10511           break;
10512
10513         case elfcpp::Tag_ABI_align8_preserved:
10514         case elfcpp::Tag_ABI_PCS_RO_data:
10515           // Use the smallest value specified.
10516           if (in_attr[i].int_value() < out_attr[i].int_value())
10517             out_attr[i].set_int_value(in_attr[i].int_value());
10518           break;
10519
10520         case elfcpp::Tag_ABI_align8_needed:
10521           if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10522               && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10523                   || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10524                       == 0)))
10525             {
10526               // This error message should be enabled once all non-conforming
10527               // binaries in the toolchain have had the attributes set
10528               // properly.
10529               // gold_error(_("output 8-byte data alignment conflicts with %s"),
10530               //            name);
10531             }
10532           // Fall through.
10533         case elfcpp::Tag_ABI_FP_denormal:
10534         case elfcpp::Tag_ABI_PCS_GOT_use:
10535           {
10536             // These tags have 0 = don't care, 1 = strong requirement,
10537             // 2 = weak requirement.
10538             static const int order_021[3] = {0, 2, 1};
10539
10540             // Use the "greatest" from the sequence 0, 2, 1, or the largest
10541             // value if greater than 2 (for future-proofing).
10542             if ((in_attr[i].int_value() > 2
10543                  && in_attr[i].int_value() > out_attr[i].int_value())
10544                 || (in_attr[i].int_value() <= 2
10545                     && out_attr[i].int_value() <= 2
10546                     && (order_021[in_attr[i].int_value()]
10547                         > order_021[out_attr[i].int_value()])))
10548               out_attr[i].set_int_value(in_attr[i].int_value());
10549           }
10550           break;
10551
10552         case elfcpp::Tag_CPU_arch_profile:
10553           if (out_attr[i].int_value() != in_attr[i].int_value())
10554             {
10555               // 0 will merge with anything.
10556               // 'A' and 'S' merge to 'A'.
10557               // 'R' and 'S' merge to 'R'.
10558               // 'M' and 'A|R|S' is an error.
10559               if (out_attr[i].int_value() == 0
10560                   || (out_attr[i].int_value() == 'S'
10561                       && (in_attr[i].int_value() == 'A'
10562                           || in_attr[i].int_value() == 'R')))
10563                 out_attr[i].set_int_value(in_attr[i].int_value());
10564               else if (in_attr[i].int_value() == 0
10565                        || (in_attr[i].int_value() == 'S'
10566                            && (out_attr[i].int_value() == 'A'
10567                                || out_attr[i].int_value() == 'R')))
10568                 ; // Do nothing.
10569               else if (parameters->options().warn_mismatch())
10570                 {
10571                   gold_error
10572                     (_("conflicting architecture profiles %c/%c"),
10573                      in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10574                      out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10575                 }
10576             }
10577           break;
10578         case elfcpp::Tag_VFP_arch:
10579             {
10580               static const struct
10581               {
10582                   int ver;
10583                   int regs;
10584               } vfp_versions[7] =
10585                 {
10586                   {0, 0},
10587                   {1, 16},
10588                   {2, 16},
10589                   {3, 32},
10590                   {3, 16},
10591                   {4, 32},
10592                   {4, 16}
10593                 };
10594
10595               // Values greater than 6 aren't defined, so just pick the
10596               // biggest.
10597               if (in_attr[i].int_value() > 6
10598                   && in_attr[i].int_value() > out_attr[i].int_value())
10599                 {
10600                   *out_attr = *in_attr;
10601                   break;
10602                 }
10603               // The output uses the superset of input features
10604               // (ISA version) and registers.
10605               int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10606                                  vfp_versions[out_attr[i].int_value()].ver);
10607               int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10608                                   vfp_versions[out_attr[i].int_value()].regs);
10609               // This assumes all possible supersets are also a valid
10610               // options.
10611               int newval;
10612               for (newval = 6; newval > 0; newval--)
10613                 {
10614                   if (regs == vfp_versions[newval].regs
10615                       && ver == vfp_versions[newval].ver)
10616                     break;
10617                 }
10618               out_attr[i].set_int_value(newval);
10619             }
10620           break;
10621         case elfcpp::Tag_PCS_config:
10622           if (out_attr[i].int_value() == 0)
10623             out_attr[i].set_int_value(in_attr[i].int_value());
10624           else if (in_attr[i].int_value() != 0
10625                    && out_attr[i].int_value() != 0
10626                    && parameters->options().warn_mismatch())
10627             {
10628               // It's sometimes ok to mix different configs, so this is only
10629               // a warning.
10630               gold_warning(_("%s: conflicting platform configuration"), name);
10631             }
10632           break;
10633         case elfcpp::Tag_ABI_PCS_R9_use:
10634           if (in_attr[i].int_value() != out_attr[i].int_value()
10635               && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10636               && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10637               && parameters->options().warn_mismatch())
10638             {
10639               gold_error(_("%s: conflicting use of R9"), name);
10640             }
10641           if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10642             out_attr[i].set_int_value(in_attr[i].int_value());
10643           break;
10644         case elfcpp::Tag_ABI_PCS_RW_data:
10645           if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10646               && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10647                   != elfcpp::AEABI_R9_SB)
10648               && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10649                   != elfcpp::AEABI_R9_unused)
10650               && parameters->options().warn_mismatch())
10651             {
10652               gold_error(_("%s: SB relative addressing conflicts with use "
10653                            "of R9"),
10654                            name);
10655             }
10656           // Use the smallest value specified.
10657           if (in_attr[i].int_value() < out_attr[i].int_value())
10658             out_attr[i].set_int_value(in_attr[i].int_value());
10659           break;
10660         case elfcpp::Tag_ABI_PCS_wchar_t:
10661           if (out_attr[i].int_value()
10662               && in_attr[i].int_value()
10663               && out_attr[i].int_value() != in_attr[i].int_value()
10664               && parameters->options().warn_mismatch()
10665               && parameters->options().wchar_size_warning())
10666             {
10667               gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10668                              "use %u-byte wchar_t; use of wchar_t values "
10669                              "across objects may fail"),
10670                            name, in_attr[i].int_value(),
10671                            out_attr[i].int_value());
10672             }
10673           else 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_enum_size:
10677           if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10678             {
10679               if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10680                   || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10681                 {
10682                   // The existing object is compatible with anything.
10683                   // Use whatever requirements the new object has.
10684                   out_attr[i].set_int_value(in_attr[i].int_value());
10685                 }
10686               else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10687                        && out_attr[i].int_value() != in_attr[i].int_value()
10688                        && parameters->options().warn_mismatch()
10689                        && parameters->options().enum_size_warning())
10690                 {
10691                   unsigned int in_value = in_attr[i].int_value();
10692                   unsigned int out_value = out_attr[i].int_value();
10693                   gold_warning(_("%s uses %s enums yet the output is to use "
10694                                  "%s enums; use of enum values across objects "
10695                                  "may fail"),
10696                                name,
10697                                this->aeabi_enum_name(in_value).c_str(),
10698                                this->aeabi_enum_name(out_value).c_str());
10699                 }
10700             }
10701           break;
10702         case elfcpp::Tag_ABI_VFP_args:
10703           // Already done.
10704           break;
10705         case elfcpp::Tag_ABI_WMMX_args:
10706           if (in_attr[i].int_value() != out_attr[i].int_value()
10707               && parameters->options().warn_mismatch())
10708             {
10709               gold_error(_("%s uses iWMMXt register arguments, output does "
10710                            "not"),
10711                          name);
10712             }
10713           break;
10714         case Object_attribute::Tag_compatibility:
10715           // Merged in target-independent code.
10716           break;
10717         case elfcpp::Tag_ABI_HardFP_use:
10718           // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10719           if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10720               || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10721             out_attr[i].set_int_value(3);
10722           else if (in_attr[i].int_value() > out_attr[i].int_value())
10723             out_attr[i].set_int_value(in_attr[i].int_value());
10724           break;
10725         case elfcpp::Tag_ABI_FP_16bit_format:
10726           if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10727             {
10728               if (in_attr[i].int_value() != out_attr[i].int_value()
10729                   && parameters->options().warn_mismatch())
10730                 gold_error(_("fp16 format mismatch between %s and output"),
10731                            name);
10732             }
10733           if (in_attr[i].int_value() != 0)
10734             out_attr[i].set_int_value(in_attr[i].int_value());
10735           break;
10736
10737         case elfcpp::Tag_DIV_use:
10738           // This tag is set to zero if we can use UDIV and SDIV in Thumb
10739           // mode on a v7-M or v7-R CPU; to one if we can not use UDIV or
10740           // SDIV at all; and to two if we can use UDIV or SDIV on a v7-A
10741           // CPU.  We will merge as follows: If the input attribute's value
10742           // is one then the output attribute's value remains unchanged.  If
10743           // the input attribute's value is zero or two then if the output
10744           // attribute's value is one the output value is set to the input
10745           // value, otherwise the output value must be the same as the
10746           // inputs.  */
10747           if (in_attr[i].int_value() != 1 && out_attr[i].int_value() != 1)
10748             {
10749               if (in_attr[i].int_value() != out_attr[i].int_value())
10750                 {
10751                   gold_error(_("DIV usage mismatch between %s and output"),
10752                              name);
10753                 }
10754             }
10755
10756           if (in_attr[i].int_value() != 1)
10757             out_attr[i].set_int_value(in_attr[i].int_value());
10758
10759           break;
10760
10761         case elfcpp::Tag_MPextension_use_legacy:
10762           // We don't output objects with Tag_MPextension_use_legacy - we
10763           // move the value to Tag_MPextension_use.
10764           if (in_attr[i].int_value() != 0
10765               && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10766             {
10767               if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10768                   != in_attr[i].int_value())
10769                 {
10770                   gold_error(_("%s has has both the current and legacy "
10771                                "Tag_MPextension_use attributes"),
10772                              name);
10773                 }
10774             }
10775
10776           if (in_attr[i].int_value()
10777               > out_attr[elfcpp::Tag_MPextension_use].int_value())
10778             out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10779
10780           break;
10781
10782         case elfcpp::Tag_nodefaults:
10783           // This tag is set if it exists, but the value is unused (and is
10784           // typically zero).  We don't actually need to do anything here -
10785           // the merge happens automatically when the type flags are merged
10786           // below.
10787           break;
10788         case elfcpp::Tag_also_compatible_with:
10789           // Already done in Tag_CPU_arch.
10790           break;
10791         case elfcpp::Tag_conformance:
10792           // Keep the attribute if it matches.  Throw it away otherwise.
10793           // No attribute means no claim to conform.
10794           if (in_attr[i].string_value() != out_attr[i].string_value())
10795             out_attr[i].set_string_value("");
10796           break;
10797
10798         default:
10799           {
10800             const char* err_object = NULL;
10801
10802             // The "known_obj_attributes" table does contain some undefined
10803             // attributes.  Ensure that there are unused.
10804             if (out_attr[i].int_value() != 0
10805                 || out_attr[i].string_value() != "")
10806               err_object = "output";
10807             else if (in_attr[i].int_value() != 0
10808                      || in_attr[i].string_value() != "")
10809               err_object = name;
10810
10811             if (err_object != NULL
10812                 && parameters->options().warn_mismatch())
10813               {
10814                 // Attribute numbers >=64 (mod 128) can be safely ignored.
10815                 if ((i & 127) < 64)
10816                   gold_error(_("%s: unknown mandatory EABI object attribute "
10817                                "%d"),
10818                              err_object, i);
10819                 else
10820                   gold_warning(_("%s: unknown EABI object attribute %d"),
10821                                err_object, i);
10822               }
10823
10824             // Only pass on attributes that match in both inputs.
10825             if (!in_attr[i].matches(out_attr[i]))
10826               {
10827                 out_attr[i].set_int_value(0);
10828                 out_attr[i].set_string_value("");
10829               }
10830           }
10831         }
10832
10833       // If out_attr was copied from in_attr then it won't have a type yet.
10834       if (in_attr[i].type() && !out_attr[i].type())
10835         out_attr[i].set_type(in_attr[i].type());
10836     }
10837
10838   // Merge Tag_compatibility attributes and any common GNU ones.
10839   this->attributes_section_data_->merge(name, pasd);
10840
10841   // Check for any attributes not known on ARM.
10842   typedef Vendor_object_attributes::Other_attributes Other_attributes;
10843   const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10844   Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10845   Other_attributes* out_other_attributes =
10846     this->attributes_section_data_->other_attributes(vendor);
10847   Other_attributes::iterator out_iter = out_other_attributes->begin();
10848
10849   while (in_iter != in_other_attributes->end()
10850          || out_iter != out_other_attributes->end())
10851     {
10852       const char* err_object = NULL;
10853       int err_tag = 0;
10854
10855       // The tags for each list are in numerical order.
10856       // If the tags are equal, then merge.
10857       if (out_iter != out_other_attributes->end()
10858           && (in_iter == in_other_attributes->end()
10859               || in_iter->first > out_iter->first))
10860         {
10861           // This attribute only exists in output.  We can't merge, and we
10862           // don't know what the tag means, so delete it.
10863           err_object = "output";
10864           err_tag = out_iter->first;
10865           int saved_tag = out_iter->first;
10866           delete out_iter->second;
10867           out_other_attributes->erase(out_iter);
10868           out_iter = out_other_attributes->upper_bound(saved_tag);
10869         }
10870       else if (in_iter != in_other_attributes->end()
10871                && (out_iter != out_other_attributes->end()
10872                    || in_iter->first < out_iter->first))
10873         {
10874           // This attribute only exists in input. We can't merge, and we
10875           // don't know what the tag means, so ignore it.
10876           err_object = name;
10877           err_tag = in_iter->first;
10878           ++in_iter;
10879         }
10880       else // The tags are equal.
10881         {
10882           // As present, all attributes in the list are unknown, and
10883           // therefore can't be merged meaningfully.
10884           err_object = "output";
10885           err_tag = out_iter->first;
10886
10887           //  Only pass on attributes that match in both inputs.
10888           if (!in_iter->second->matches(*(out_iter->second)))
10889             {
10890               // No match.  Delete the attribute.
10891               int saved_tag = out_iter->first;
10892               delete out_iter->second;
10893               out_other_attributes->erase(out_iter);
10894               out_iter = out_other_attributes->upper_bound(saved_tag);
10895             }
10896           else
10897             {
10898               // Matched.  Keep the attribute and move to the next.
10899               ++out_iter;
10900               ++in_iter;
10901             }
10902         }
10903
10904       if (err_object && parameters->options().warn_mismatch())
10905         {
10906           // Attribute numbers >=64 (mod 128) can be safely ignored.  */
10907           if ((err_tag & 127) < 64)
10908             {
10909               gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10910                          err_object, err_tag);
10911             }
10912           else
10913             {
10914               gold_warning(_("%s: unknown EABI object attribute %d"),
10915                            err_object, err_tag);
10916             }
10917         }
10918     }
10919 }
10920
10921 // Stub-generation methods for Target_arm.
10922
10923 // Make a new Arm_input_section object.
10924
10925 template<bool big_endian>
10926 Arm_input_section<big_endian>*
10927 Target_arm<big_endian>::new_arm_input_section(
10928     Relobj* relobj,
10929     unsigned int shndx)
10930 {
10931   Section_id sid(relobj, shndx);
10932
10933   Arm_input_section<big_endian>* arm_input_section =
10934     new Arm_input_section<big_endian>(relobj, shndx);
10935   arm_input_section->init();
10936
10937   // Register new Arm_input_section in map for look-up.
10938   std::pair<typename Arm_input_section_map::iterator, bool> ins =
10939     this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
10940
10941   // Make sure that it we have not created another Arm_input_section
10942   // for this input section already.
10943   gold_assert(ins.second);
10944
10945   return arm_input_section;
10946 }
10947
10948 // Find the Arm_input_section object corresponding to the SHNDX-th input
10949 // section of RELOBJ.
10950
10951 template<bool big_endian>
10952 Arm_input_section<big_endian>*
10953 Target_arm<big_endian>::find_arm_input_section(
10954     Relobj* relobj,
10955     unsigned int shndx) const
10956 {
10957   Section_id sid(relobj, shndx);
10958   typename Arm_input_section_map::const_iterator p =
10959     this->arm_input_section_map_.find(sid);
10960   return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
10961 }
10962
10963 // Make a new stub table.
10964
10965 template<bool big_endian>
10966 Stub_table<big_endian>*
10967 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
10968 {
10969   Stub_table<big_endian>* stub_table =
10970     new Stub_table<big_endian>(owner);
10971   this->stub_tables_.push_back(stub_table);
10972
10973   stub_table->set_address(owner->address() + owner->data_size());
10974   stub_table->set_file_offset(owner->offset() + owner->data_size());
10975   stub_table->finalize_data_size();
10976
10977   return stub_table;
10978 }
10979
10980 // Scan a relocation for stub generation.
10981
10982 template<bool big_endian>
10983 void
10984 Target_arm<big_endian>::scan_reloc_for_stub(
10985     const Relocate_info<32, big_endian>* relinfo,
10986     unsigned int r_type,
10987     const Sized_symbol<32>* gsym,
10988     unsigned int r_sym,
10989     const Symbol_value<32>* psymval,
10990     elfcpp::Elf_types<32>::Elf_Swxword addend,
10991     Arm_address address)
10992 {
10993   typedef typename Target_arm<big_endian>::Relocate Relocate;
10994
10995   const Arm_relobj<big_endian>* arm_relobj =
10996     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10997
10998   bool target_is_thumb;
10999   Symbol_value<32> symval;
11000   if (gsym != NULL)
11001     {
11002       // This is a global symbol.  Determine if we use PLT and if the
11003       // final target is THUMB.
11004       if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
11005         {
11006           // This uses a PLT, change the symbol value.
11007           symval.set_output_value(this->plt_section()->address()
11008                                   + gsym->plt_offset());
11009           psymval = &symval;
11010           target_is_thumb = false;
11011         }
11012       else if (gsym->is_undefined())
11013         // There is no need to generate a stub symbol is undefined.
11014         return;
11015       else
11016         {
11017           target_is_thumb =
11018             ((gsym->type() == elfcpp::STT_ARM_TFUNC)
11019              || (gsym->type() == elfcpp::STT_FUNC
11020                  && !gsym->is_undefined()
11021                  && ((psymval->value(arm_relobj, 0) & 1) != 0)));
11022         }
11023     }
11024   else
11025     {
11026       // This is a local symbol.  Determine if the final target is THUMB.
11027       target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
11028     }
11029
11030   // Strip LSB if this points to a THUMB target.
11031   const Arm_reloc_property* reloc_property =
11032     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
11033   gold_assert(reloc_property != NULL);
11034   if (target_is_thumb
11035       && reloc_property->uses_thumb_bit()
11036       && ((psymval->value(arm_relobj, 0) & 1) != 0))
11037     {
11038       Arm_address stripped_value =
11039         psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
11040       symval.set_output_value(stripped_value);
11041       psymval = &symval;
11042     }
11043
11044   // Get the symbol value.
11045   Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
11046
11047   // Owing to pipelining, the PC relative branches below actually skip
11048   // two instructions when the branch offset is 0.
11049   Arm_address destination;
11050   switch (r_type)
11051     {
11052     case elfcpp::R_ARM_CALL:
11053     case elfcpp::R_ARM_JUMP24:
11054     case elfcpp::R_ARM_PLT32:
11055       // ARM branches.
11056       destination = value + addend + 8;
11057       break;
11058     case elfcpp::R_ARM_THM_CALL:
11059     case elfcpp::R_ARM_THM_XPC22:
11060     case elfcpp::R_ARM_THM_JUMP24:
11061     case elfcpp::R_ARM_THM_JUMP19:
11062       // THUMB branches.
11063       destination = value + addend + 4;
11064       break;
11065     default:
11066       gold_unreachable();
11067     }
11068
11069   Reloc_stub* stub = NULL;
11070   Stub_type stub_type =
11071     Reloc_stub::stub_type_for_reloc(r_type, address, destination,
11072                                     target_is_thumb);
11073   if (stub_type != arm_stub_none)
11074     {
11075       // Try looking up an existing stub from a stub table.
11076       Stub_table<big_endian>* stub_table =
11077         arm_relobj->stub_table(relinfo->data_shndx);
11078       gold_assert(stub_table != NULL);
11079
11080       // Locate stub by destination.
11081       Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
11082
11083       // Create a stub if there is not one already
11084       stub = stub_table->find_reloc_stub(stub_key);
11085       if (stub == NULL)
11086         {
11087           // create a new stub and add it to stub table.
11088           stub = this->stub_factory().make_reloc_stub(stub_type);
11089           stub_table->add_reloc_stub(stub, stub_key);
11090         }
11091
11092       // Record the destination address.
11093       stub->set_destination_address(destination
11094                                     | (target_is_thumb ? 1 : 0));
11095     }
11096
11097   // For Cortex-A8, we need to record a relocation at 4K page boundary.
11098   if (this->fix_cortex_a8_
11099       && (r_type == elfcpp::R_ARM_THM_JUMP24
11100           || r_type == elfcpp::R_ARM_THM_JUMP19
11101           || r_type == elfcpp::R_ARM_THM_CALL
11102           || r_type == elfcpp::R_ARM_THM_XPC22)
11103       && (address & 0xfffU) == 0xffeU)
11104     {
11105       // Found a candidate.  Note we haven't checked the destination is
11106       // within 4K here: if we do so (and don't create a record) we can't
11107       // tell that a branch should have been relocated when scanning later.
11108       this->cortex_a8_relocs_info_[address] =
11109         new Cortex_a8_reloc(stub, r_type,
11110                             destination | (target_is_thumb ? 1 : 0));
11111     }
11112 }
11113
11114 // This function scans a relocation sections for stub generation.
11115 // The template parameter Relocate must be a class type which provides
11116 // a single function, relocate(), which implements the machine
11117 // specific part of a relocation.
11118
11119 // BIG_ENDIAN is the endianness of the data.  SH_TYPE is the section type:
11120 // SHT_REL or SHT_RELA.
11121
11122 // PRELOCS points to the relocation data.  RELOC_COUNT is the number
11123 // of relocs.  OUTPUT_SECTION is the output section.
11124 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
11125 // mapped to output offsets.
11126
11127 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
11128 // VIEW_SIZE is the size.  These refer to the input section, unless
11129 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
11130 // the output section.
11131
11132 template<bool big_endian>
11133 template<int sh_type>
11134 void inline
11135 Target_arm<big_endian>::scan_reloc_section_for_stubs(
11136     const Relocate_info<32, big_endian>* relinfo,
11137     const unsigned char* prelocs,
11138     size_t reloc_count,
11139     Output_section* output_section,
11140     bool needs_special_offset_handling,
11141     const unsigned char* view,
11142     elfcpp::Elf_types<32>::Elf_Addr view_address,
11143     section_size_type)
11144 {
11145   typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
11146   const int reloc_size =
11147     Reloc_types<sh_type, 32, big_endian>::reloc_size;
11148
11149   Arm_relobj<big_endian>* arm_object =
11150     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11151   unsigned int local_count = arm_object->local_symbol_count();
11152
11153   Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11154
11155   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11156     {
11157       Reltype reloc(prelocs);
11158
11159       typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11160       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11161       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11162
11163       r_type = this->get_real_reloc_type(r_type);
11164
11165       // Only a few relocation types need stubs.
11166       if ((r_type != elfcpp::R_ARM_CALL)
11167          && (r_type != elfcpp::R_ARM_JUMP24)
11168          && (r_type != elfcpp::R_ARM_PLT32)
11169          && (r_type != elfcpp::R_ARM_THM_CALL)
11170          && (r_type != elfcpp::R_ARM_THM_XPC22)
11171          && (r_type != elfcpp::R_ARM_THM_JUMP24)
11172          && (r_type != elfcpp::R_ARM_THM_JUMP19)
11173          && (r_type != elfcpp::R_ARM_V4BX))
11174         continue;
11175
11176       section_offset_type offset =
11177         convert_to_section_size_type(reloc.get_r_offset());
11178
11179       if (needs_special_offset_handling)
11180         {
11181           offset = output_section->output_offset(relinfo->object,
11182                                                  relinfo->data_shndx,
11183                                                  offset);
11184           if (offset == -1)
11185             continue;
11186         }
11187
11188       // Create a v4bx stub if --fix-v4bx-interworking is used.
11189       if (r_type == elfcpp::R_ARM_V4BX)
11190         {
11191           if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11192             {
11193               // Get the BX instruction.
11194               typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11195               const Valtype* wv =
11196                 reinterpret_cast<const Valtype*>(view + offset);
11197               elfcpp::Elf_types<32>::Elf_Swxword insn =
11198                 elfcpp::Swap<32, big_endian>::readval(wv);
11199               const uint32_t reg = (insn & 0xf);
11200
11201               if (reg < 0xf)
11202                 {
11203                   // Try looking up an existing stub from a stub table.
11204                   Stub_table<big_endian>* stub_table =
11205                     arm_object->stub_table(relinfo->data_shndx);
11206                   gold_assert(stub_table != NULL);
11207
11208                   if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11209                     {
11210                       // create a new stub and add it to stub table.
11211                       Arm_v4bx_stub* stub =
11212                         this->stub_factory().make_arm_v4bx_stub(reg);
11213                       gold_assert(stub != NULL);
11214                       stub_table->add_arm_v4bx_stub(stub);
11215                     }
11216                 }
11217             }
11218           continue;
11219         }
11220
11221       // Get the addend.
11222       Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11223       elfcpp::Elf_types<32>::Elf_Swxword addend =
11224         stub_addend_reader(r_type, view + offset, reloc);
11225
11226       const Sized_symbol<32>* sym;
11227
11228       Symbol_value<32> symval;
11229       const Symbol_value<32> *psymval;
11230       bool is_defined_in_discarded_section;
11231       unsigned int shndx;
11232       if (r_sym < local_count)
11233         {
11234           sym = NULL;
11235           psymval = arm_object->local_symbol(r_sym);
11236
11237           // If the local symbol belongs to a section we are discarding,
11238           // and that section is a debug section, try to find the
11239           // corresponding kept section and map this symbol to its
11240           // counterpart in the kept section.  The symbol must not
11241           // correspond to a section we are folding.
11242           bool is_ordinary;
11243           shndx = psymval->input_shndx(&is_ordinary);
11244           is_defined_in_discarded_section =
11245             (is_ordinary
11246              && shndx != elfcpp::SHN_UNDEF
11247              && !arm_object->is_section_included(shndx)
11248              && !relinfo->symtab->is_section_folded(arm_object, shndx));
11249
11250           // We need to compute the would-be final value of this local
11251           // symbol.
11252           if (!is_defined_in_discarded_section)
11253             {
11254               typedef Sized_relobj_file<32, big_endian> ObjType;
11255               typename ObjType::Compute_final_local_value_status status =
11256                 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11257                                                       relinfo->symtab);
11258               if (status == ObjType::CFLV_OK)
11259                 {
11260                   // Currently we cannot handle a branch to a target in
11261                   // a merged section.  If this is the case, issue an error
11262                   // and also free the merge symbol value.
11263                   if (!symval.has_output_value())
11264                     {
11265                       const std::string& section_name =
11266                         arm_object->section_name(shndx);
11267                       arm_object->error(_("cannot handle branch to local %u "
11268                                           "in a merged section %s"),
11269                                         r_sym, section_name.c_str());
11270                     }
11271                   psymval = &symval;
11272                 }
11273               else
11274                 {
11275                   // We cannot determine the final value.
11276                   continue;
11277                 }
11278             }
11279         }
11280       else
11281         {
11282           const Symbol* gsym;
11283           gsym = arm_object->global_symbol(r_sym);
11284           gold_assert(gsym != NULL);
11285           if (gsym->is_forwarder())
11286             gsym = relinfo->symtab->resolve_forwards(gsym);
11287
11288           sym = static_cast<const Sized_symbol<32>*>(gsym);
11289           if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11290             symval.set_output_symtab_index(sym->symtab_index());
11291           else
11292             symval.set_no_output_symtab_entry();
11293
11294           // We need to compute the would-be final value of this global
11295           // symbol.
11296           const Symbol_table* symtab = relinfo->symtab;
11297           const Sized_symbol<32>* sized_symbol =
11298             symtab->get_sized_symbol<32>(gsym);
11299           Symbol_table::Compute_final_value_status status;
11300           Arm_address value =
11301             symtab->compute_final_value<32>(sized_symbol, &status);
11302
11303           // Skip this if the symbol has not output section.
11304           if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11305             continue;
11306           symval.set_output_value(value);
11307
11308           if (gsym->type() == elfcpp::STT_TLS)
11309             symval.set_is_tls_symbol();
11310           else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11311             symval.set_is_ifunc_symbol();
11312           psymval = &symval;
11313
11314           is_defined_in_discarded_section =
11315             (gsym->is_defined_in_discarded_section()
11316              && gsym->is_undefined());
11317           shndx = 0;
11318         }
11319
11320       Symbol_value<32> symval2;
11321       if (is_defined_in_discarded_section)
11322         {
11323           if (comdat_behavior == CB_UNDETERMINED)
11324             {
11325               std::string name = arm_object->section_name(relinfo->data_shndx);
11326               comdat_behavior = get_comdat_behavior(name.c_str());
11327             }
11328           if (comdat_behavior == CB_PRETEND)
11329             {
11330               // FIXME: This case does not work for global symbols.
11331               // We have no place to store the original section index.
11332               // Fortunately this does not matter for comdat sections,
11333               // only for sections explicitly discarded by a linker
11334               // script.
11335               bool found;
11336               typename elfcpp::Elf_types<32>::Elf_Addr value =
11337                 arm_object->map_to_kept_section(shndx, &found);
11338               if (found)
11339                 symval2.set_output_value(value + psymval->input_value());
11340               else
11341                 symval2.set_output_value(0);
11342             }
11343           else
11344             {
11345               if (comdat_behavior == CB_WARNING)
11346                 gold_warning_at_location(relinfo, i, offset,
11347                                          _("relocation refers to discarded "
11348                                            "section"));
11349               symval2.set_output_value(0);
11350             }
11351           symval2.set_no_output_symtab_entry();
11352           psymval = &symval2;
11353         }
11354
11355       // If symbol is a section symbol, we don't know the actual type of
11356       // destination.  Give up.
11357       if (psymval->is_section_symbol())
11358         continue;
11359
11360       this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11361                                 addend, view_address + offset);
11362     }
11363 }
11364
11365 // Scan an input section for stub generation.
11366
11367 template<bool big_endian>
11368 void
11369 Target_arm<big_endian>::scan_section_for_stubs(
11370     const Relocate_info<32, big_endian>* relinfo,
11371     unsigned int sh_type,
11372     const unsigned char* prelocs,
11373     size_t reloc_count,
11374     Output_section* output_section,
11375     bool needs_special_offset_handling,
11376     const unsigned char* view,
11377     Arm_address view_address,
11378     section_size_type view_size)
11379 {
11380   if (sh_type == elfcpp::SHT_REL)
11381     this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11382         relinfo,
11383         prelocs,
11384         reloc_count,
11385         output_section,
11386         needs_special_offset_handling,
11387         view,
11388         view_address,
11389         view_size);
11390   else if (sh_type == elfcpp::SHT_RELA)
11391     // We do not support RELA type relocations yet.  This is provided for
11392     // completeness.
11393     this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11394         relinfo,
11395         prelocs,
11396         reloc_count,
11397         output_section,
11398         needs_special_offset_handling,
11399         view,
11400         view_address,
11401         view_size);
11402   else
11403     gold_unreachable();
11404 }
11405
11406 // Group input sections for stub generation.
11407 //
11408 // We group input sections in an output section so that the total size,
11409 // including any padding space due to alignment is smaller than GROUP_SIZE
11410 // unless the only input section in group is bigger than GROUP_SIZE already.
11411 // Then an ARM stub table is created to follow the last input section
11412 // in group.  For each group an ARM stub table is created an is placed
11413 // after the last group.  If STUB_ALWAYS_AFTER_BRANCH is false, we further
11414 // extend the group after the stub table.
11415
11416 template<bool big_endian>
11417 void
11418 Target_arm<big_endian>::group_sections(
11419     Layout* layout,
11420     section_size_type group_size,
11421     bool stubs_always_after_branch,
11422     const Task* task)
11423 {
11424   // Group input sections and insert stub table
11425   Layout::Section_list section_list;
11426   layout->get_allocated_sections(&section_list);
11427   for (Layout::Section_list::const_iterator p = section_list.begin();
11428        p != section_list.end();
11429        ++p)
11430     {
11431       Arm_output_section<big_endian>* output_section =
11432         Arm_output_section<big_endian>::as_arm_output_section(*p);
11433       output_section->group_sections(group_size, stubs_always_after_branch,
11434                                      this, task);
11435     }
11436 }
11437
11438 // Relaxation hook.  This is where we do stub generation.
11439
11440 template<bool big_endian>
11441 bool
11442 Target_arm<big_endian>::do_relax(
11443     int pass,
11444     const Input_objects* input_objects,
11445     Symbol_table* symtab,
11446     Layout* layout,
11447     const Task* task)
11448 {
11449   // No need to generate stubs if this is a relocatable link.
11450   gold_assert(!parameters->options().relocatable());
11451
11452   // If this is the first pass, we need to group input sections into
11453   // stub groups.
11454   bool done_exidx_fixup = false;
11455   typedef typename Stub_table_list::iterator Stub_table_iterator;
11456   if (pass == 1)
11457     {
11458       // Determine the stub group size.  The group size is the absolute
11459       // value of the parameter --stub-group-size.  If --stub-group-size
11460       // is passed a negative value, we restrict stubs to be always after
11461       // the stubbed branches.
11462       int32_t stub_group_size_param =
11463         parameters->options().stub_group_size();
11464       bool stubs_always_after_branch = stub_group_size_param < 0;
11465       section_size_type stub_group_size = abs(stub_group_size_param);
11466
11467       if (stub_group_size == 1)
11468         {
11469           // Default value.
11470           // Thumb branch range is +-4MB has to be used as the default
11471           // maximum size (a given section can contain both ARM and Thumb
11472           // code, so the worst case has to be taken into account).  If we are
11473           // fixing cortex-a8 errata, the branch range has to be even smaller,
11474           // since wide conditional branch has a range of +-1MB only.
11475           //
11476           // This value is 48K less than that, which allows for 4096
11477           // 12-byte stubs.  If we exceed that, then we will fail to link.
11478           // The user will have to relink with an explicit group size
11479           // option.
11480             stub_group_size = 4145152;
11481         }
11482
11483       // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11484       // page as the first half of a 32-bit branch straddling two 4K pages.
11485       // This is a crude way of enforcing that.  In addition, long conditional
11486       // branches of THUMB-2 have a range of +-1M.  If we are fixing cortex-A8
11487       // erratum, limit the group size to  (1M - 12k) to avoid unreachable
11488       // cortex-A8 stubs from long conditional branches.
11489       if (this->fix_cortex_a8_)
11490         {
11491           stubs_always_after_branch = true;
11492           const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11493           stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11494         }
11495
11496       group_sections(layout, stub_group_size, stubs_always_after_branch, task);
11497
11498       // Also fix .ARM.exidx section coverage.
11499       Arm_output_section<big_endian>* exidx_output_section = NULL;
11500       for (Layout::Section_list::const_iterator p =
11501              layout->section_list().begin();
11502            p != layout->section_list().end();
11503            ++p)
11504         if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11505           {
11506             if (exidx_output_section == NULL)
11507               exidx_output_section =
11508                 Arm_output_section<big_endian>::as_arm_output_section(*p);
11509             else
11510               // We cannot handle this now.
11511               gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11512                            "non-relocatable link"),
11513                           exidx_output_section->name(),
11514                           (*p)->name());
11515           }
11516
11517       if (exidx_output_section != NULL)
11518         {
11519           this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11520                                    symtab, task);
11521           done_exidx_fixup = true;
11522         }
11523     }
11524   else
11525     {
11526       // If this is not the first pass, addresses and file offsets have
11527       // been reset at this point, set them here.
11528       for (Stub_table_iterator sp = this->stub_tables_.begin();
11529            sp != this->stub_tables_.end();
11530            ++sp)
11531         {
11532           Arm_input_section<big_endian>* owner = (*sp)->owner();
11533           off_t off = align_address(owner->original_size(),
11534                                     (*sp)->addralign());
11535           (*sp)->set_address_and_file_offset(owner->address() + off,
11536                                              owner->offset() + off);
11537         }
11538     }
11539
11540   // The Cortex-A8 stubs are sensitive to layout of code sections.  At the
11541   // beginning of each relaxation pass, just blow away all the stubs.
11542   // Alternatively, we could selectively remove only the stubs and reloc
11543   // information for code sections that have moved since the last pass.
11544   // That would require more book-keeping.
11545   if (this->fix_cortex_a8_)
11546     {
11547       // Clear all Cortex-A8 reloc information.
11548       for (typename Cortex_a8_relocs_info::const_iterator p =
11549              this->cortex_a8_relocs_info_.begin();
11550            p != this->cortex_a8_relocs_info_.end();
11551            ++p)
11552         delete p->second;
11553       this->cortex_a8_relocs_info_.clear();
11554
11555       // Remove all Cortex-A8 stubs.
11556       for (Stub_table_iterator sp = this->stub_tables_.begin();
11557            sp != this->stub_tables_.end();
11558            ++sp)
11559         (*sp)->remove_all_cortex_a8_stubs();
11560     }
11561
11562   // Scan relocs for relocation stubs
11563   for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11564        op != input_objects->relobj_end();
11565        ++op)
11566     {
11567       Arm_relobj<big_endian>* arm_relobj =
11568         Arm_relobj<big_endian>::as_arm_relobj(*op);
11569       // Lock the object so we can read from it.  This is only called
11570       // single-threaded from Layout::finalize, so it is OK to lock.
11571       Task_lock_obj<Object> tl(task, arm_relobj);
11572       arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11573     }
11574
11575   // Check all stub tables to see if any of them have their data sizes
11576   // or addresses alignments changed.  These are the only things that
11577   // matter.
11578   bool any_stub_table_changed = false;
11579   Unordered_set<const Output_section*> sections_needing_adjustment;
11580   for (Stub_table_iterator sp = this->stub_tables_.begin();
11581        (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11582        ++sp)
11583     {
11584       if ((*sp)->update_data_size_and_addralign())
11585         {
11586           // Update data size of stub table owner.
11587           Arm_input_section<big_endian>* owner = (*sp)->owner();
11588           uint64_t address = owner->address();
11589           off_t offset = owner->offset();
11590           owner->reset_address_and_file_offset();
11591           owner->set_address_and_file_offset(address, offset);
11592
11593           sections_needing_adjustment.insert(owner->output_section());
11594           any_stub_table_changed = true;
11595         }
11596     }
11597
11598   // Output_section_data::output_section() returns a const pointer but we
11599   // need to update output sections, so we record all output sections needing
11600   // update above and scan the sections here to find out what sections need
11601   // to be updated.
11602   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
11603       p != layout->section_list().end();
11604       ++p)
11605     {
11606       if (sections_needing_adjustment.find(*p)
11607           != sections_needing_adjustment.end())
11608         (*p)->set_section_offsets_need_adjustment();
11609     }
11610
11611   // Stop relaxation if no EXIDX fix-up and no stub table change.
11612   bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11613
11614   // Finalize the stubs in the last relaxation pass.
11615   if (!continue_relaxation)
11616     {
11617       for (Stub_table_iterator sp = this->stub_tables_.begin();
11618            (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11619             ++sp)
11620         (*sp)->finalize_stubs();
11621
11622       // Update output local symbol counts of objects if necessary.
11623       for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11624            op != input_objects->relobj_end();
11625            ++op)
11626         {
11627           Arm_relobj<big_endian>* arm_relobj =
11628             Arm_relobj<big_endian>::as_arm_relobj(*op);
11629
11630           // Update output local symbol counts.  We need to discard local
11631           // symbols defined in parts of input sections that are discarded by
11632           // relaxation.
11633           if (arm_relobj->output_local_symbol_count_needs_update())
11634             {
11635               // We need to lock the object's file to update it.
11636               Task_lock_obj<Object> tl(task, arm_relobj);
11637               arm_relobj->update_output_local_symbol_count();
11638             }
11639         }
11640     }
11641
11642   return continue_relaxation;
11643 }
11644
11645 // Relocate a stub.
11646
11647 template<bool big_endian>
11648 void
11649 Target_arm<big_endian>::relocate_stub(
11650     Stub* stub,
11651     const Relocate_info<32, big_endian>* relinfo,
11652     Output_section* output_section,
11653     unsigned char* view,
11654     Arm_address address,
11655     section_size_type view_size)
11656 {
11657   Relocate relocate;
11658   const Stub_template* stub_template = stub->stub_template();
11659   for (size_t i = 0; i < stub_template->reloc_count(); i++)
11660     {
11661       size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11662       const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11663
11664       unsigned int r_type = insn->r_type();
11665       section_size_type reloc_offset = stub_template->reloc_offset(i);
11666       section_size_type reloc_size = insn->size();
11667       gold_assert(reloc_offset + reloc_size <= view_size);
11668
11669       // This is the address of the stub destination.
11670       Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11671       Symbol_value<32> symval;
11672       symval.set_output_value(target);
11673
11674       // Synthesize a fake reloc just in case.  We don't have a symbol so
11675       // we use 0.
11676       unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11677       memset(reloc_buffer, 0, sizeof(reloc_buffer));
11678       elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11679       reloc_write.put_r_offset(reloc_offset);
11680       reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11681       elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11682
11683       relocate.relocate(relinfo, this, output_section,
11684                         this->fake_relnum_for_stubs, rel, r_type,
11685                         NULL, &symval, view + reloc_offset,
11686                         address + reloc_offset, reloc_size);
11687     }
11688 }
11689
11690 // Determine whether an object attribute tag takes an integer, a
11691 // string or both.
11692
11693 template<bool big_endian>
11694 int
11695 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11696 {
11697   if (tag == Object_attribute::Tag_compatibility)
11698     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11699             | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11700   else if (tag == elfcpp::Tag_nodefaults)
11701     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11702             | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11703   else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11704     return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11705   else if (tag < 32)
11706     return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11707   else
11708     return ((tag & 1) != 0
11709             ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11710             : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11711 }
11712
11713 // Reorder attributes.
11714 //
11715 // The ABI defines that Tag_conformance should be emitted first, and that
11716 // Tag_nodefaults should be second (if either is defined).  This sets those
11717 // two positions, and bumps up the position of all the remaining tags to
11718 // compensate.
11719
11720 template<bool big_endian>
11721 int
11722 Target_arm<big_endian>::do_attributes_order(int num) const
11723 {
11724   // Reorder the known object attributes in output.  We want to move
11725   // Tag_conformance to position 4 and Tag_conformance to position 5
11726   // and shift everything between 4 .. Tag_conformance - 1 to make room.
11727   if (num == 4)
11728     return elfcpp::Tag_conformance;
11729   if (num == 5)
11730     return elfcpp::Tag_nodefaults;
11731   if ((num - 2) < elfcpp::Tag_nodefaults)
11732     return num - 2;
11733   if ((num - 1) < elfcpp::Tag_conformance)
11734     return num - 1;
11735   return num;
11736 }
11737
11738 // Scan a span of THUMB code for Cortex-A8 erratum.
11739
11740 template<bool big_endian>
11741 void
11742 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11743     Arm_relobj<big_endian>* arm_relobj,
11744     unsigned int shndx,
11745     section_size_type span_start,
11746     section_size_type span_end,
11747     const unsigned char* view,
11748     Arm_address address)
11749 {
11750   // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11751   //
11752   // The opcode is BLX.W, BL.W, B.W, Bcc.W
11753   // The branch target is in the same 4KB region as the
11754   // first half of the branch.
11755   // The instruction before the branch is a 32-bit
11756   // length non-branch instruction.
11757   section_size_type i = span_start;
11758   bool last_was_32bit = false;
11759   bool last_was_branch = false;
11760   while (i < span_end)
11761     {
11762       typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11763       const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11764       uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11765       bool is_blx = false, is_b = false;
11766       bool is_bl = false, is_bcc = false;
11767
11768       bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11769       if (insn_32bit)
11770         {
11771           // Load the rest of the insn (in manual-friendly order).
11772           insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11773
11774           // Encoding T4: B<c>.W.
11775           is_b = (insn & 0xf800d000U) == 0xf0009000U;
11776           // Encoding T1: BL<c>.W.
11777           is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11778           // Encoding T2: BLX<c>.W.
11779           is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11780           // Encoding T3: B<c>.W (not permitted in IT block).
11781           is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11782                     && (insn & 0x07f00000U) != 0x03800000U);
11783         }
11784
11785       bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11786
11787       // If this instruction is a 32-bit THUMB branch that crosses a 4K
11788       // page boundary and it follows 32-bit non-branch instruction,
11789       // we need to work around.
11790       if (is_32bit_branch
11791           && ((address + i) & 0xfffU) == 0xffeU
11792           && last_was_32bit
11793           && !last_was_branch)
11794         {
11795           // Check to see if there is a relocation stub for this branch.
11796           bool force_target_arm = false;
11797           bool force_target_thumb = false;
11798           const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11799           Cortex_a8_relocs_info::const_iterator p =
11800             this->cortex_a8_relocs_info_.find(address + i);
11801
11802           if (p != this->cortex_a8_relocs_info_.end())
11803             {
11804               cortex_a8_reloc = p->second;
11805               bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11806
11807               if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11808                   && !target_is_thumb)
11809                 force_target_arm = true;
11810               else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11811                        && target_is_thumb)
11812                 force_target_thumb = true;
11813             }
11814
11815           off_t offset;
11816           Stub_type stub_type = arm_stub_none;
11817
11818           // Check if we have an offending branch instruction.
11819           uint16_t upper_insn = (insn >> 16) & 0xffffU;
11820           uint16_t lower_insn = insn & 0xffffU;
11821           typedef class Arm_relocate_functions<big_endian> RelocFuncs;
11822
11823           if (cortex_a8_reloc != NULL
11824               && cortex_a8_reloc->reloc_stub() != NULL)
11825             // We've already made a stub for this instruction, e.g.
11826             // it's a long branch or a Thumb->ARM stub.  Assume that
11827             // stub will suffice to work around the A8 erratum (see
11828             // setting of always_after_branch above).
11829             ;
11830           else if (is_bcc)
11831             {
11832               offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11833                                                               lower_insn);
11834               stub_type = arm_stub_a8_veneer_b_cond;
11835             }
11836           else if (is_b || is_bl || is_blx)
11837             {
11838               offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11839                                                          lower_insn);
11840               if (is_blx)
11841                 offset &= ~3;
11842
11843               stub_type = (is_blx
11844                            ? arm_stub_a8_veneer_blx
11845                            : (is_bl
11846                               ? arm_stub_a8_veneer_bl
11847                               : arm_stub_a8_veneer_b));
11848             }
11849
11850           if (stub_type != arm_stub_none)
11851             {
11852               Arm_address pc_for_insn = address + i + 4;
11853
11854               // The original instruction is a BL, but the target is
11855               // an ARM instruction.  If we were not making a stub,
11856               // the BL would have been converted to a BLX.  Use the
11857               // BLX stub instead in that case.
11858               if (this->may_use_v5t_interworking() && force_target_arm
11859                   && stub_type == arm_stub_a8_veneer_bl)
11860                 {
11861                   stub_type = arm_stub_a8_veneer_blx;
11862                   is_blx = true;
11863                   is_bl = false;
11864                 }
11865               // Conversely, if the original instruction was
11866               // BLX but the target is Thumb mode, use the BL stub.
11867               else if (force_target_thumb
11868                        && stub_type == arm_stub_a8_veneer_blx)
11869                 {
11870                   stub_type = arm_stub_a8_veneer_bl;
11871                   is_blx = false;
11872                   is_bl = true;
11873                 }
11874
11875               if (is_blx)
11876                 pc_for_insn &= ~3;
11877
11878               // If we found a relocation, use the proper destination,
11879               // not the offset in the (unrelocated) instruction.
11880               // Note this is always done if we switched the stub type above.
11881               if (cortex_a8_reloc != NULL)
11882                 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11883
11884               Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11885
11886               // Add a new stub if destination address in in the same page.
11887               if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11888                 {
11889                   Cortex_a8_stub* stub =
11890                     this->stub_factory_.make_cortex_a8_stub(stub_type,
11891                                                             arm_relobj, shndx,
11892                                                             address + i,
11893                                                             target, insn);
11894                   Stub_table<big_endian>* stub_table =
11895                     arm_relobj->stub_table(shndx);
11896                   gold_assert(stub_table != NULL);
11897                   stub_table->add_cortex_a8_stub(address + i, stub);
11898                 }
11899             }
11900         }
11901
11902       i += insn_32bit ? 4 : 2;
11903       last_was_32bit = insn_32bit;
11904       last_was_branch = is_32bit_branch;
11905     }
11906 }
11907
11908 // Apply the Cortex-A8 workaround.
11909
11910 template<bool big_endian>
11911 void
11912 Target_arm<big_endian>::apply_cortex_a8_workaround(
11913     const Cortex_a8_stub* stub,
11914     Arm_address stub_address,
11915     unsigned char* insn_view,
11916     Arm_address insn_address)
11917 {
11918   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11919   Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
11920   Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
11921   Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
11922   off_t branch_offset = stub_address - (insn_address + 4);
11923
11924   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
11925   switch (stub->stub_template()->type())
11926     {
11927     case arm_stub_a8_veneer_b_cond:
11928       // For a conditional branch, we re-write it to be an unconditional
11929       // branch to the stub.  We use the THUMB-2 encoding here.
11930       upper_insn = 0xf000U;
11931       lower_insn = 0xb800U;
11932       // Fall through
11933     case arm_stub_a8_veneer_b:
11934     case arm_stub_a8_veneer_bl:
11935     case arm_stub_a8_veneer_blx:
11936       if ((lower_insn & 0x5000U) == 0x4000U)
11937         // For a BLX instruction, make sure that the relocation is
11938         // rounded up to a word boundary.  This follows the semantics of
11939         // the instruction which specifies that bit 1 of the target
11940         // address will come from bit 1 of the base address.
11941         branch_offset = (branch_offset + 2) & ~3;
11942
11943       // Put BRANCH_OFFSET back into the insn.
11944       gold_assert(!Bits<25>::has_overflow32(branch_offset));
11945       upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
11946       lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
11947       break;
11948
11949     default:
11950       gold_unreachable();
11951     }
11952
11953   // Put the relocated value back in the object file:
11954   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
11955   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
11956 }
11957
11958 // Target selector for ARM.  Note this is never instantiated directly.
11959 // It's only used in Target_selector_arm_nacl, below.
11960
11961 template<bool big_endian>
11962 class Target_selector_arm : public Target_selector
11963 {
11964  public:
11965   Target_selector_arm()
11966     : Target_selector(elfcpp::EM_ARM, 32, big_endian,
11967                       (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
11968                       (big_endian ? "armelfb" : "armelf"))
11969   { }
11970
11971   Target*
11972   do_instantiate_target()
11973   { return new Target_arm<big_endian>(); }
11974 };
11975
11976 // Fix .ARM.exidx section coverage.
11977
11978 template<bool big_endian>
11979 void
11980 Target_arm<big_endian>::fix_exidx_coverage(
11981     Layout* layout,
11982     const Input_objects* input_objects,
11983     Arm_output_section<big_endian>* exidx_section,
11984     Symbol_table* symtab,
11985     const Task* task)
11986 {
11987   // We need to look at all the input sections in output in ascending
11988   // order of of output address.  We do that by building a sorted list
11989   // of output sections by addresses.  Then we looks at the output sections
11990   // in order.  The input sections in an output section are already sorted
11991   // by addresses within the output section.
11992
11993   typedef std::set<Output_section*, output_section_address_less_than>
11994       Sorted_output_section_list;
11995   Sorted_output_section_list sorted_output_sections;
11996
11997   // Find out all the output sections of input sections pointed by
11998   // EXIDX input sections.
11999   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
12000        p != input_objects->relobj_end();
12001        ++p)
12002     {
12003       Arm_relobj<big_endian>* arm_relobj =
12004         Arm_relobj<big_endian>::as_arm_relobj(*p);
12005       std::vector<unsigned int> shndx_list;
12006       arm_relobj->get_exidx_shndx_list(&shndx_list);
12007       for (size_t i = 0; i < shndx_list.size(); ++i)
12008         {
12009           const Arm_exidx_input_section* exidx_input_section =
12010             arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
12011           gold_assert(exidx_input_section != NULL);
12012           if (!exidx_input_section->has_errors())
12013             {
12014               unsigned int text_shndx = exidx_input_section->link();
12015               Output_section* os = arm_relobj->output_section(text_shndx);
12016               if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
12017                 sorted_output_sections.insert(os);
12018             }
12019         }
12020     }
12021
12022   // Go over the output sections in ascending order of output addresses.
12023   typedef typename Arm_output_section<big_endian>::Text_section_list
12024       Text_section_list;
12025   Text_section_list sorted_text_sections;
12026   for (typename Sorted_output_section_list::iterator p =
12027         sorted_output_sections.begin();
12028       p != sorted_output_sections.end();
12029       ++p)
12030     {
12031       Arm_output_section<big_endian>* arm_output_section =
12032         Arm_output_section<big_endian>::as_arm_output_section(*p);
12033       arm_output_section->append_text_sections_to_list(&sorted_text_sections);
12034     }
12035
12036   exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
12037                                     merge_exidx_entries(), task);
12038 }
12039
12040 template<bool big_endian>
12041 void
12042 Target_arm<big_endian>::do_define_standard_symbols(
12043     Symbol_table* symtab,
12044     Layout* layout)
12045 {
12046   // Handle the .ARM.exidx section.
12047   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
12048
12049   if (exidx_section != NULL)
12050     {
12051       // Create __exidx_start and __exidx_end symbols.
12052       symtab->define_in_output_data("__exidx_start",
12053                                     NULL, // version
12054                                     Symbol_table::PREDEFINED,
12055                                     exidx_section,
12056                                     0, // value
12057                                     0, // symsize
12058                                     elfcpp::STT_NOTYPE,
12059                                     elfcpp::STB_GLOBAL,
12060                                     elfcpp::STV_HIDDEN,
12061                                     0, // nonvis
12062                                     false, // offset_is_from_end
12063                                     true); // only_if_ref
12064
12065       symtab->define_in_output_data("__exidx_end",
12066                                     NULL, // version
12067                                     Symbol_table::PREDEFINED,
12068                                     exidx_section,
12069                                     0, // value
12070                                     0, // symsize
12071                                     elfcpp::STT_NOTYPE,
12072                                     elfcpp::STB_GLOBAL,
12073                                     elfcpp::STV_HIDDEN,
12074                                     0, // nonvis
12075                                     true, // offset_is_from_end
12076                                     true); // only_if_ref
12077     }
12078   else
12079     {
12080       // Define __exidx_start and __exidx_end even when .ARM.exidx
12081       // section is missing to match ld's behaviour.
12082       symtab->define_as_constant("__exidx_start", NULL,
12083                                  Symbol_table::PREDEFINED,
12084                                  0, 0, elfcpp::STT_OBJECT,
12085                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12086                                  true, false);
12087       symtab->define_as_constant("__exidx_end", NULL,
12088                                  Symbol_table::PREDEFINED,
12089                                  0, 0, elfcpp::STT_OBJECT,
12090                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12091                                  true, false);
12092     }
12093 }
12094
12095 // NaCl variant.  It uses different PLT contents.
12096
12097 template<bool big_endian>
12098 class Output_data_plt_arm_nacl;
12099
12100 template<bool big_endian>
12101 class Target_arm_nacl : public Target_arm<big_endian>
12102 {
12103  public:
12104   Target_arm_nacl()
12105     : Target_arm<big_endian>(&arm_nacl_info)
12106   { }
12107
12108  protected:
12109   virtual Output_data_plt_arm<big_endian>*
12110   do_make_data_plt(Layout* layout, Output_data_space* got_plt)
12111   { return new Output_data_plt_arm_nacl<big_endian>(layout, got_plt); }
12112
12113  private:
12114   static const Target::Target_info arm_nacl_info;
12115 };
12116
12117 template<bool big_endian>
12118 const Target::Target_info Target_arm_nacl<big_endian>::arm_nacl_info =
12119 {
12120   32,                   // size
12121   big_endian,           // is_big_endian
12122   elfcpp::EM_ARM,       // machine_code
12123   false,                // has_make_symbol
12124   false,                // has_resolve
12125   false,                // has_code_fill
12126   true,                 // is_default_stack_executable
12127   false,                // can_icf_inline_merge_sections
12128   '\0',                 // wrap_char
12129   "/lib/ld-nacl-arm.so.1", // dynamic_linker
12130   0x20000,              // default_text_segment_address
12131   0x10000,              // abi_pagesize (overridable by -z max-page-size)
12132   0x10000,              // common_pagesize (overridable by -z common-page-size)
12133   true,                 // isolate_execinstr
12134   0x10000000,           // rosegment_gap
12135   elfcpp::SHN_UNDEF,    // small_common_shndx
12136   elfcpp::SHN_UNDEF,    // large_common_shndx
12137   0,                    // small_common_section_flags
12138   0,                    // large_common_section_flags
12139   ".ARM.attributes",    // attributes_section
12140   "aeabi"               // attributes_vendor
12141 };
12142
12143 template<bool big_endian>
12144 class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
12145 {
12146  public:
12147   Output_data_plt_arm_nacl(Layout* layout, Output_data_space* got_plt)
12148     : Output_data_plt_arm<big_endian>(layout, 16, got_plt)
12149   { }
12150
12151  protected:
12152   // Return the offset of the first non-reserved PLT entry.
12153   virtual unsigned int
12154   do_first_plt_entry_offset() const
12155   { return sizeof(first_plt_entry); }
12156
12157   // Return the size of a PLT entry.
12158   virtual unsigned int
12159   do_get_plt_entry_size() const
12160   { return sizeof(plt_entry); }
12161
12162   virtual void
12163   do_fill_first_plt_entry(unsigned char* pov,
12164                           Arm_address got_address,
12165                           Arm_address plt_address);
12166
12167   virtual void
12168   do_fill_plt_entry(unsigned char* pov,
12169                     Arm_address got_address,
12170                     Arm_address plt_address,
12171                     unsigned int got_offset,
12172                     unsigned int plt_offset);
12173
12174  private:
12175   inline uint32_t arm_movw_immediate(uint32_t value)
12176   {
12177     return (value & 0x00000fff) | ((value & 0x0000f000) << 4);
12178   }
12179
12180   inline uint32_t arm_movt_immediate(uint32_t value)
12181   {
12182     return ((value & 0x0fff0000) >> 16) | ((value & 0xf0000000) >> 12);
12183   }
12184
12185   // Template for the first PLT entry.
12186   static const uint32_t first_plt_entry[16];
12187
12188   // Template for subsequent PLT entries.
12189   static const uint32_t plt_entry[4];
12190 };
12191
12192 // The first entry in the PLT.
12193 template<bool big_endian>
12194 const uint32_t Output_data_plt_arm_nacl<big_endian>::first_plt_entry[16] =
12195 {
12196   // First bundle:
12197   0xe300c000,                           // movw ip, #:lower16:&GOT[2]-.+8
12198   0xe340c000,                           // movt ip, #:upper16:&GOT[2]-.+8
12199   0xe08cc00f,                           // add  ip, ip, pc
12200   0xe52dc008,                           // str  ip, [sp, #-8]!
12201   // Second bundle:
12202   0xe7dfcf1f,                           // bfc  ip, #30, #2
12203   0xe59cc000,                           // ldr  ip, [ip]
12204   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
12205   0xe12fff1c,                           // bx   ip
12206   // Third bundle:
12207   0xe320f000,                           // nop
12208   0xe320f000,                           // nop
12209   0xe320f000,                           // nop
12210   // .Lplt_tail:
12211   0xe50dc004,                           // str  ip, [sp, #-4]
12212   // Fourth bundle:
12213   0xe7dfcf1f,                           // bfc  ip, #30, #2
12214   0xe59cc000,                           // ldr  ip, [ip]
12215   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
12216   0xe12fff1c,                           // bx   ip
12217 };
12218
12219 template<bool big_endian>
12220 void
12221 Output_data_plt_arm_nacl<big_endian>::do_fill_first_plt_entry(
12222     unsigned char* pov,
12223     Arm_address got_address,
12224     Arm_address plt_address)
12225 {
12226   // Write first PLT entry.  All but first two words are constants.
12227   const size_t num_first_plt_words = (sizeof(first_plt_entry)
12228                                       / sizeof(first_plt_entry[0]));
12229
12230   int32_t got_displacement = got_address + 8 - (plt_address + 16);
12231
12232   elfcpp::Swap<32, big_endian>::writeval
12233     (pov + 0, first_plt_entry[0] | arm_movw_immediate (got_displacement));
12234   elfcpp::Swap<32, big_endian>::writeval
12235     (pov + 4, first_plt_entry[1] | arm_movt_immediate (got_displacement));
12236
12237   for (size_t i = 2; i < num_first_plt_words; ++i)
12238     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
12239 }
12240
12241 // Subsequent entries in the PLT.
12242
12243 template<bool big_endian>
12244 const uint32_t Output_data_plt_arm_nacl<big_endian>::plt_entry[4] =
12245 {
12246   0xe300c000,                           // movw ip, #:lower16:&GOT[n]-.+8
12247   0xe340c000,                           // movt ip, #:upper16:&GOT[n]-.+8
12248   0xe08cc00f,                           // add  ip, ip, pc
12249   0xea000000,                           // b    .Lplt_tail
12250 };
12251
12252 template<bool big_endian>
12253 void
12254 Output_data_plt_arm_nacl<big_endian>::do_fill_plt_entry(
12255     unsigned char* pov,
12256     Arm_address got_address,
12257     Arm_address plt_address,
12258     unsigned int got_offset,
12259     unsigned int plt_offset)
12260 {
12261   // Calculate the displacement between the PLT slot and the
12262   // common tail that's part of the special initial PLT slot.
12263   int32_t tail_displacement = (plt_address + (11 * sizeof(uint32_t))
12264                                - (plt_address + plt_offset
12265                                   + sizeof(plt_entry) + sizeof(uint32_t)));
12266   gold_assert((tail_displacement & 3) == 0);
12267   tail_displacement >>= 2;
12268
12269   gold_assert ((tail_displacement & 0xff000000) == 0
12270                || (-tail_displacement & 0xff000000) == 0);
12271
12272   // Calculate the displacement between the PLT slot and the entry
12273   // in the GOT.  The offset accounts for the value produced by
12274   // adding to pc in the penultimate instruction of the PLT stub.
12275   const int32_t got_displacement = (got_address + got_offset
12276                                     - (plt_address + sizeof(plt_entry)));
12277
12278   elfcpp::Swap<32, big_endian>::writeval
12279     (pov + 0, plt_entry[0] | arm_movw_immediate (got_displacement));
12280   elfcpp::Swap<32, big_endian>::writeval
12281     (pov + 4, plt_entry[1] | arm_movt_immediate (got_displacement));
12282   elfcpp::Swap<32, big_endian>::writeval
12283     (pov + 8, plt_entry[2]);
12284   elfcpp::Swap<32, big_endian>::writeval
12285     (pov + 12, plt_entry[3] | (tail_displacement & 0x00ffffff));
12286 }
12287
12288 // Target selectors.
12289
12290 template<bool big_endian>
12291 class Target_selector_arm_nacl
12292   : public Target_selector_nacl<Target_selector_arm<big_endian>,
12293                                 Target_arm_nacl<big_endian> >
12294 {
12295  public:
12296   Target_selector_arm_nacl()
12297     : Target_selector_nacl<Target_selector_arm<big_endian>,
12298                            Target_arm_nacl<big_endian> >(
12299           "arm",
12300           big_endian ? "elf32-bigarm-nacl" : "elf32-littlearm-nacl",
12301           big_endian ? "armelfb_nacl" : "armelf_nacl")
12302   { }
12303 };
12304
12305 Target_selector_arm_nacl<false> target_selector_arm;
12306 Target_selector_arm_nacl<true> target_selector_armbe;
12307
12308 } // End anonymous namespace.