* target-reloc.h (class Default_comdat_behavior): New, package up..
[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   // Emit relocations for a section.
2290   void
2291   relocate_relocs(const Relocate_info<32, big_endian>*,
2292                   unsigned int sh_type,
2293                   const unsigned char* prelocs,
2294                   size_t reloc_count,
2295                   Output_section* output_section,
2296                   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           bool is_discarded);
2556
2557     inline void
2558     global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2559            Sized_relobj_file<32, big_endian>* object,
2560            unsigned int data_shndx,
2561            Output_section* output_section,
2562            const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2563            Symbol* gsym);
2564
2565     inline bool
2566     local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2567                                         Sized_relobj_file<32, big_endian>* ,
2568                                         unsigned int ,
2569                                         Output_section* ,
2570                                         const elfcpp::Rel<32, big_endian>& ,
2571                                         unsigned int ,
2572                                         const elfcpp::Sym<32, big_endian>&);
2573
2574     inline bool
2575     global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2576                                          Sized_relobj_file<32, big_endian>* ,
2577                                          unsigned int ,
2578                                          Output_section* ,
2579                                          const elfcpp::Rel<32, big_endian>& ,
2580                                          unsigned int , Symbol*);
2581
2582    private:
2583     static void
2584     unsupported_reloc_local(Sized_relobj_file<32, big_endian>*,
2585                             unsigned int r_type);
2586
2587     static void
2588     unsupported_reloc_global(Sized_relobj_file<32, big_endian>*,
2589                              unsigned int r_type, Symbol*);
2590
2591     void
2592     check_non_pic(Relobj*, unsigned int r_type);
2593
2594     // Almost identical to Symbol::needs_plt_entry except that it also
2595     // handles STT_ARM_TFUNC.
2596     static bool
2597     symbol_needs_plt_entry(const Symbol* sym)
2598     {
2599       // An undefined symbol from an executable does not need a PLT entry.
2600       if (sym->is_undefined() && !parameters->options().shared())
2601         return false;
2602
2603       return (!parameters->doing_static_link()
2604               && (sym->type() == elfcpp::STT_FUNC
2605                   || sym->type() == elfcpp::STT_ARM_TFUNC)
2606               && (sym->is_from_dynobj()
2607                   || sym->is_undefined()
2608                   || sym->is_preemptible()));
2609     }
2610
2611     inline bool
2612     possible_function_pointer_reloc(unsigned int r_type);
2613
2614     // Whether we have issued an error about a non-PIC compilation.
2615     bool issued_non_pic_error_;
2616   };
2617
2618   // The class which implements relocation.
2619   class Relocate
2620   {
2621    public:
2622     Relocate()
2623     { }
2624
2625     ~Relocate()
2626     { }
2627
2628     // Return whether the static relocation needs to be applied.
2629     inline bool
2630     should_apply_static_reloc(const Sized_symbol<32>* gsym,
2631                               unsigned int r_type,
2632                               bool is_32bit,
2633                               Output_section* output_section);
2634
2635     // Do a relocation.  Return false if the caller should not issue
2636     // any warnings about this relocation.
2637     inline bool
2638     relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2639              Output_section*,  size_t relnum,
2640              const elfcpp::Rel<32, big_endian>&,
2641              unsigned int r_type, const Sized_symbol<32>*,
2642              const Symbol_value<32>*,
2643              unsigned char*, Arm_address,
2644              section_size_type);
2645
2646     // Return whether we want to pass flag NON_PIC_REF for this
2647     // reloc.  This means the relocation type accesses a symbol not via
2648     // GOT or PLT.
2649     static inline bool
2650     reloc_is_non_pic(unsigned int r_type)
2651     {
2652       switch (r_type)
2653         {
2654         // These relocation types reference GOT or PLT entries explicitly.
2655         case elfcpp::R_ARM_GOT_BREL:
2656         case elfcpp::R_ARM_GOT_ABS:
2657         case elfcpp::R_ARM_GOT_PREL:
2658         case elfcpp::R_ARM_GOT_BREL12:
2659         case elfcpp::R_ARM_PLT32_ABS:
2660         case elfcpp::R_ARM_TLS_GD32:
2661         case elfcpp::R_ARM_TLS_LDM32:
2662         case elfcpp::R_ARM_TLS_IE32:
2663         case elfcpp::R_ARM_TLS_IE12GP:
2664
2665         // These relocate types may use PLT entries.
2666         case elfcpp::R_ARM_CALL:
2667         case elfcpp::R_ARM_THM_CALL:
2668         case elfcpp::R_ARM_JUMP24:
2669         case elfcpp::R_ARM_THM_JUMP24:
2670         case elfcpp::R_ARM_THM_JUMP19:
2671         case elfcpp::R_ARM_PLT32:
2672         case elfcpp::R_ARM_THM_XPC22:
2673         case elfcpp::R_ARM_PREL31:
2674         case elfcpp::R_ARM_SBREL31:
2675           return false;
2676
2677         default:
2678           return true;
2679         }
2680     }
2681
2682    private:
2683     // Do a TLS relocation.
2684     inline typename Arm_relocate_functions<big_endian>::Status
2685     relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2686                  size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2687                  const Sized_symbol<32>*, const Symbol_value<32>*,
2688                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2689                  section_size_type);
2690
2691   };
2692
2693   // A class which returns the size required for a relocation type,
2694   // used while scanning relocs during a relocatable link.
2695   class Relocatable_size_for_reloc
2696   {
2697    public:
2698     unsigned int
2699     get_size_for_reloc(unsigned int, Relobj*);
2700   };
2701
2702   // Adjust TLS relocation type based on the options and whether this
2703   // is a local symbol.
2704   static tls::Tls_optimization
2705   optimize_tls_reloc(bool is_final, int r_type);
2706
2707   // Get the GOT section, creating it if necessary.
2708   Arm_output_data_got<big_endian>*
2709   got_section(Symbol_table*, Layout*);
2710
2711   // Get the GOT PLT section.
2712   Output_data_space*
2713   got_plt_section() const
2714   {
2715     gold_assert(this->got_plt_ != NULL);
2716     return this->got_plt_;
2717   }
2718
2719   // Create a PLT entry for a global symbol.
2720   void
2721   make_plt_entry(Symbol_table*, Layout*, Symbol*);
2722
2723   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2724   void
2725   define_tls_base_symbol(Symbol_table*, Layout*);
2726
2727   // Create a GOT entry for the TLS module index.
2728   unsigned int
2729   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2730                       Sized_relobj_file<32, big_endian>* object);
2731
2732   // Get the PLT section.
2733   const Output_data_plt_arm<big_endian>*
2734   plt_section() const
2735   {
2736     gold_assert(this->plt_ != NULL);
2737     return this->plt_;
2738   }
2739
2740   // Get the dynamic reloc section, creating it if necessary.
2741   Reloc_section*
2742   rel_dyn_section(Layout*);
2743
2744   // Get the section to use for TLS_DESC relocations.
2745   Reloc_section*
2746   rel_tls_desc_section(Layout*) const;
2747
2748   // Return true if the symbol may need a COPY relocation.
2749   // References from an executable object to non-function symbols
2750   // defined in a dynamic object may need a COPY relocation.
2751   bool
2752   may_need_copy_reloc(Symbol* gsym)
2753   {
2754     return (gsym->type() != elfcpp::STT_ARM_TFUNC
2755             && gsym->may_need_copy_reloc());
2756   }
2757
2758   // Add a potential copy relocation.
2759   void
2760   copy_reloc(Symbol_table* symtab, Layout* layout,
2761              Sized_relobj_file<32, big_endian>* object,
2762              unsigned int shndx, Output_section* output_section,
2763              Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2764   {
2765     this->copy_relocs_.copy_reloc(symtab, layout,
2766                                   symtab->get_sized_symbol<32>(sym),
2767                                   object, shndx, output_section, reloc,
2768                                   this->rel_dyn_section(layout));
2769   }
2770
2771   // Whether two EABI versions are compatible.
2772   static bool
2773   are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2774
2775   // Merge processor-specific flags from input object and those in the ELF
2776   // header of the output.
2777   void
2778   merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2779
2780   // Get the secondary compatible architecture.
2781   static int
2782   get_secondary_compatible_arch(const Attributes_section_data*);
2783
2784   // Set the secondary compatible architecture.
2785   static void
2786   set_secondary_compatible_arch(Attributes_section_data*, int);
2787
2788   static int
2789   tag_cpu_arch_combine(const char*, int, int*, int, int);
2790
2791   // Helper to print AEABI enum tag value.
2792   static std::string
2793   aeabi_enum_name(unsigned int);
2794
2795   // Return string value for TAG_CPU_name.
2796   static std::string
2797   tag_cpu_name_value(unsigned int);
2798
2799   // Merge object attributes from input object and those in the output.
2800   void
2801   merge_object_attributes(const char*, const Attributes_section_data*);
2802
2803   // Helper to get an AEABI object attribute
2804   Object_attribute*
2805   get_aeabi_object_attribute(int tag) const
2806   {
2807     Attributes_section_data* pasd = this->attributes_section_data_;
2808     gold_assert(pasd != NULL);
2809     Object_attribute* attr =
2810       pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2811     gold_assert(attr != NULL);
2812     return attr;
2813   }
2814
2815   //
2816   // Methods to support stub-generations.
2817   //
2818
2819   // Group input sections for stub generation.
2820   void
2821   group_sections(Layout*, section_size_type, bool, const Task*);
2822
2823   // Scan a relocation for stub generation.
2824   void
2825   scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2826                       const Sized_symbol<32>*, unsigned int,
2827                       const Symbol_value<32>*,
2828                       elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2829
2830   // Scan a relocation section for stub.
2831   template<int sh_type>
2832   void
2833   scan_reloc_section_for_stubs(
2834       const Relocate_info<32, big_endian>* relinfo,
2835       const unsigned char* prelocs,
2836       size_t reloc_count,
2837       Output_section* output_section,
2838       bool needs_special_offset_handling,
2839       const unsigned char* view,
2840       elfcpp::Elf_types<32>::Elf_Addr view_address,
2841       section_size_type);
2842
2843   // Fix .ARM.exidx section coverage.
2844   void
2845   fix_exidx_coverage(Layout*, const Input_objects*,
2846                      Arm_output_section<big_endian>*, Symbol_table*,
2847                      const Task*);
2848
2849   // Functors for STL set.
2850   struct output_section_address_less_than
2851   {
2852     bool
2853     operator()(const Output_section* s1, const Output_section* s2) const
2854     { return s1->address() < s2->address(); }
2855   };
2856
2857   // Information about this specific target which we pass to the
2858   // general Target structure.
2859   static const Target::Target_info arm_info;
2860
2861   // The types of GOT entries needed for this platform.
2862   // These values are exposed to the ABI in an incremental link.
2863   // Do not renumber existing values without changing the version
2864   // number of the .gnu_incremental_inputs section.
2865   enum Got_type
2866   {
2867     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
2868     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
2869     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
2870     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
2871     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
2872   };
2873
2874   typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2875
2876   // Map input section to Arm_input_section.
2877   typedef Unordered_map<Section_id,
2878                         Arm_input_section<big_endian>*,
2879                         Section_id_hash>
2880           Arm_input_section_map;
2881
2882   // Map output addresses to relocs for Cortex-A8 erratum.
2883   typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2884           Cortex_a8_relocs_info;
2885
2886   // The GOT section.
2887   Arm_output_data_got<big_endian>* got_;
2888   // The PLT section.
2889   Output_data_plt_arm<big_endian>* plt_;
2890   // The GOT PLT section.
2891   Output_data_space* got_plt_;
2892   // The dynamic reloc section.
2893   Reloc_section* rel_dyn_;
2894   // Relocs saved to avoid a COPY reloc.
2895   Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2896   // Space for variables copied with a COPY reloc.
2897   Output_data_space* dynbss_;
2898   // Offset of the GOT entry for the TLS module index.
2899   unsigned int got_mod_index_offset_;
2900   // True if the _TLS_MODULE_BASE_ symbol has been defined.
2901   bool tls_base_symbol_defined_;
2902   // Vector of Stub_tables created.
2903   Stub_table_list stub_tables_;
2904   // Stub factory.
2905   const Stub_factory &stub_factory_;
2906   // Whether we force PIC branch veneers.
2907   bool should_force_pic_veneer_;
2908   // Map for locating Arm_input_sections.
2909   Arm_input_section_map arm_input_section_map_;
2910   // Attributes section data in output.
2911   Attributes_section_data* attributes_section_data_;
2912   // Whether we want to fix code for Cortex-A8 erratum.
2913   bool fix_cortex_a8_;
2914   // Map addresses to relocs for Cortex-A8 erratum.
2915   Cortex_a8_relocs_info cortex_a8_relocs_info_;
2916 };
2917
2918 template<bool big_endian>
2919 const Target::Target_info Target_arm<big_endian>::arm_info =
2920 {
2921   32,                   // size
2922   big_endian,           // is_big_endian
2923   elfcpp::EM_ARM,       // machine_code
2924   false,                // has_make_symbol
2925   false,                // has_resolve
2926   false,                // has_code_fill
2927   true,                 // is_default_stack_executable
2928   false,                // can_icf_inline_merge_sections
2929   '\0',                 // wrap_char
2930   "/usr/lib/libc.so.1", // dynamic_linker
2931   0x8000,               // default_text_segment_address
2932   0x1000,               // abi_pagesize (overridable by -z max-page-size)
2933   0x1000,               // common_pagesize (overridable by -z common-page-size)
2934   false,                // isolate_execinstr
2935   0,                    // rosegment_gap
2936   elfcpp::SHN_UNDEF,    // small_common_shndx
2937   elfcpp::SHN_UNDEF,    // large_common_shndx
2938   0,                    // small_common_section_flags
2939   0,                    // large_common_section_flags
2940   ".ARM.attributes",    // attributes_section
2941   "aeabi"               // attributes_vendor
2942 };
2943
2944 // Arm relocate functions class
2945 //
2946
2947 template<bool big_endian>
2948 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2949 {
2950  public:
2951   typedef enum
2952   {
2953     STATUS_OKAY,        // No error during relocation.
2954     STATUS_OVERFLOW,    // Relocation overflow.
2955     STATUS_BAD_RELOC    // Relocation cannot be applied.
2956   } Status;
2957
2958  private:
2959   typedef Relocate_functions<32, big_endian> Base;
2960   typedef Arm_relocate_functions<big_endian> This;
2961
2962   // Encoding of imm16 argument for movt and movw ARM instructions
2963   // from ARM ARM:
2964   //
2965   //     imm16 := imm4 | imm12
2966   //
2967   //  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
2968   // +-------+---------------+-------+-------+-----------------------+
2969   // |       |               |imm4   |       |imm12                  |
2970   // +-------+---------------+-------+-------+-----------------------+
2971
2972   // Extract the relocation addend from VAL based on the ARM
2973   // instruction encoding described above.
2974   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2975   extract_arm_movw_movt_addend(
2976       typename elfcpp::Swap<32, big_endian>::Valtype val)
2977   {
2978     // According to the Elf ABI for ARM Architecture the immediate
2979     // field is sign-extended to form the addend.
2980     return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff));
2981   }
2982
2983   // Insert X into VAL based on the ARM instruction encoding described
2984   // above.
2985   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2986   insert_val_arm_movw_movt(
2987       typename elfcpp::Swap<32, big_endian>::Valtype val,
2988       typename elfcpp::Swap<32, big_endian>::Valtype x)
2989   {
2990     val &= 0xfff0f000;
2991     val |= x & 0x0fff;
2992     val |= (x & 0xf000) << 4;
2993     return val;
2994   }
2995
2996   // Encoding of imm16 argument for movt and movw Thumb2 instructions
2997   // from ARM ARM:
2998   //
2999   //     imm16 := imm4 | i | imm3 | imm8
3000   //
3001   //  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
3002   // +---------+-+-----------+-------++-+-----+-------+---------------+
3003   // |         |i|           |imm4   || |imm3 |       |imm8           |
3004   // +---------+-+-----------+-------++-+-----+-------+---------------+
3005
3006   // Extract the relocation addend from VAL based on the Thumb2
3007   // instruction encoding described above.
3008   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3009   extract_thumb_movw_movt_addend(
3010       typename elfcpp::Swap<32, big_endian>::Valtype val)
3011   {
3012     // According to the Elf ABI for ARM Architecture the immediate
3013     // field is sign-extended to form the addend.
3014     return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
3015                                    | ((val >> 15) & 0x0800)
3016                                    | ((val >> 4) & 0x0700)
3017                                    | (val & 0x00ff));
3018   }
3019
3020   // Insert X into VAL based on the Thumb2 instruction encoding
3021   // described above.
3022   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3023   insert_val_thumb_movw_movt(
3024       typename elfcpp::Swap<32, big_endian>::Valtype val,
3025       typename elfcpp::Swap<32, big_endian>::Valtype x)
3026   {
3027     val &= 0xfbf08f00;
3028     val |= (x & 0xf000) << 4;
3029     val |= (x & 0x0800) << 15;
3030     val |= (x & 0x0700) << 4;
3031     val |= (x & 0x00ff);
3032     return val;
3033   }
3034
3035   // Calculate the smallest constant Kn for the specified residual.
3036   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3037   static uint32_t
3038   calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3039   {
3040     int32_t msb;
3041
3042     if (residual == 0)
3043       return 0;
3044     // Determine the most significant bit in the residual and
3045     // align the resulting value to a 2-bit boundary.
3046     for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3047       ;
3048     // The desired shift is now (msb - 6), or zero, whichever
3049     // is the greater.
3050     return (((msb - 6) < 0) ? 0 : (msb - 6));
3051   }
3052
3053   // Calculate the final residual for the specified group index.
3054   // If the passed group index is less than zero, the method will return
3055   // the value of the specified residual without any change.
3056   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3057   static typename elfcpp::Swap<32, big_endian>::Valtype
3058   calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3059                     const int group)
3060   {
3061     for (int n = 0; n <= group; n++)
3062       {
3063         // Calculate which part of the value to mask.
3064         uint32_t shift = calc_grp_kn(residual);
3065         // Calculate the residual for the next time around.
3066         residual &= ~(residual & (0xff << shift));
3067       }
3068
3069     return residual;
3070   }
3071
3072   // Calculate the value of Gn for the specified group index.
3073   // We return it in the form of an encoded constant-and-rotation.
3074   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3075   static typename elfcpp::Swap<32, big_endian>::Valtype
3076   calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3077               const int group)
3078   {
3079     typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3080     uint32_t shift = 0;
3081
3082     for (int n = 0; n <= group; n++)
3083       {
3084         // Calculate which part of the value to mask.
3085         shift = calc_grp_kn(residual);
3086         // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3087         gn = residual & (0xff << shift);
3088         // Calculate the residual for the next time around.
3089         residual &= ~gn;
3090       }
3091     // Return Gn in the form of an encoded constant-and-rotation.
3092     return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3093   }
3094
3095  public:
3096   // Handle ARM long branches.
3097   static typename This::Status
3098   arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3099                     unsigned char*, const Sized_symbol<32>*,
3100                     const Arm_relobj<big_endian>*, unsigned int,
3101                     const Symbol_value<32>*, Arm_address, Arm_address, bool);
3102
3103   // Handle THUMB long branches.
3104   static typename This::Status
3105   thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3106                       unsigned char*, const Sized_symbol<32>*,
3107                       const Arm_relobj<big_endian>*, unsigned int,
3108                       const Symbol_value<32>*, Arm_address, Arm_address, bool);
3109
3110
3111   // Return the branch offset of a 32-bit THUMB branch.
3112   static inline int32_t
3113   thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3114   {
3115     // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3116     // involving the J1 and J2 bits.
3117     uint32_t s = (upper_insn & (1U << 10)) >> 10;
3118     uint32_t upper = upper_insn & 0x3ffU;
3119     uint32_t lower = lower_insn & 0x7ffU;
3120     uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3121     uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3122     uint32_t i1 = j1 ^ s ? 0 : 1;
3123     uint32_t i2 = j2 ^ s ? 0 : 1;
3124
3125     return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3126                                    | (upper << 12) | (lower << 1));
3127   }
3128
3129   // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3130   // UPPER_INSN is the original upper instruction of the branch.  Caller is
3131   // responsible for overflow checking and BLX offset adjustment.
3132   static inline uint16_t
3133   thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3134   {
3135     uint32_t s = offset < 0 ? 1 : 0;
3136     uint32_t bits = static_cast<uint32_t>(offset);
3137     return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3138   }
3139
3140   // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3141   // LOWER_INSN is the original lower instruction of the branch.  Caller is
3142   // responsible for overflow checking and BLX offset adjustment.
3143   static inline uint16_t
3144   thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3145   {
3146     uint32_t s = offset < 0 ? 1 : 0;
3147     uint32_t bits = static_cast<uint32_t>(offset);
3148     return ((lower_insn & ~0x2fffU)
3149             | ((((bits >> 23) & 1) ^ !s) << 13)
3150             | ((((bits >> 22) & 1) ^ !s) << 11)
3151             | ((bits >> 1) & 0x7ffU));
3152   }
3153
3154   // Return the branch offset of a 32-bit THUMB conditional branch.
3155   static inline int32_t
3156   thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3157   {
3158     uint32_t s = (upper_insn & 0x0400U) >> 10;
3159     uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3160     uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3161     uint32_t lower = (lower_insn & 0x07ffU);
3162     uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3163
3164     return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3165   }
3166
3167   // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3168   // instruction.  UPPER_INSN is the original upper instruction of the branch.
3169   // Caller is responsible for overflow checking.
3170   static inline uint16_t
3171   thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3172   {
3173     uint32_t s = offset < 0 ? 1 : 0;
3174     uint32_t bits = static_cast<uint32_t>(offset);
3175     return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3176   }
3177
3178   // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3179   // instruction.  LOWER_INSN is the original lower instruction of the branch.
3180   // The caller is responsible for overflow checking.
3181   static inline uint16_t
3182   thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3183   {
3184     uint32_t bits = static_cast<uint32_t>(offset);
3185     uint32_t j2 = (bits & 0x00080000U) >> 19;
3186     uint32_t j1 = (bits & 0x00040000U) >> 18;
3187     uint32_t lo = (bits & 0x00000ffeU) >> 1;
3188
3189     return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3190   }
3191
3192   // R_ARM_ABS8: S + A
3193   static inline typename This::Status
3194   abs8(unsigned char* view,
3195        const Sized_relobj_file<32, big_endian>* object,
3196        const Symbol_value<32>* psymval)
3197   {
3198     typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3199     Valtype* wv = reinterpret_cast<Valtype*>(view);
3200     Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3201     int32_t addend = Bits<8>::sign_extend32(val);
3202     Arm_address x = psymval->value(object, addend);
3203     val = Bits<32>::bit_select32(val, x, 0xffU);
3204     elfcpp::Swap<8, big_endian>::writeval(wv, val);
3205
3206     // R_ARM_ABS8 permits signed or unsigned results.
3207     return (Bits<8>::has_signed_unsigned_overflow32(x)
3208             ? This::STATUS_OVERFLOW
3209             : This::STATUS_OKAY);
3210   }
3211
3212   // R_ARM_THM_ABS5: S + A
3213   static inline typename This::Status
3214   thm_abs5(unsigned char* view,
3215        const Sized_relobj_file<32, big_endian>* object,
3216        const Symbol_value<32>* psymval)
3217   {
3218     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3219     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3220     Valtype* wv = reinterpret_cast<Valtype*>(view);
3221     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3222     Reltype addend = (val & 0x7e0U) >> 6;
3223     Reltype x = psymval->value(object, addend);
3224     val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3225     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3226     return (Bits<5>::has_overflow32(x)
3227             ? This::STATUS_OVERFLOW
3228             : This::STATUS_OKAY);
3229   }
3230
3231   // R_ARM_ABS12: S + A
3232   static inline typename This::Status
3233   abs12(unsigned char* view,
3234         const Sized_relobj_file<32, big_endian>* object,
3235         const Symbol_value<32>* psymval)
3236   {
3237     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3238     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3239     Valtype* wv = reinterpret_cast<Valtype*>(view);
3240     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3241     Reltype addend = val & 0x0fffU;
3242     Reltype x = psymval->value(object, addend);
3243     val = Bits<32>::bit_select32(val, x, 0x0fffU);
3244     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3245     return (Bits<12>::has_overflow32(x)
3246             ? This::STATUS_OVERFLOW
3247             : This::STATUS_OKAY);
3248   }
3249
3250   // R_ARM_ABS16: S + A
3251   static inline typename This::Status
3252   abs16(unsigned char* view,
3253         const Sized_relobj_file<32, big_endian>* object,
3254         const Symbol_value<32>* psymval)
3255   {
3256     typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
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   Output_section* os = this->relobj_->output_section(this->shndx_);
5213   gold_assert(os != NULL);
5214
5215   Arm_relobj<big_endian>* arm_relobj =
5216     Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5217   Arm_address output_offset =
5218     arm_relobj->get_output_section_offset(this->shndx_);
5219   Arm_address section_start;
5220   section_size_type section_size;
5221
5222   // Find out the end of the text section referred by this.
5223   if (output_offset != Arm_relobj<big_endian>::invalid_address)
5224     {
5225       section_start = os->address() + output_offset;
5226       const Arm_exidx_input_section* exidx_input_section =
5227         arm_relobj->exidx_input_section_by_link(this->shndx_);
5228       gold_assert(exidx_input_section != NULL);
5229       section_size =
5230         convert_to_section_size_type(exidx_input_section->text_size());
5231     }
5232   else
5233     {
5234       // Currently this only happens for a relaxed section.
5235       const Output_relaxed_input_section* poris =
5236         os->find_relaxed_input_section(this->relobj_, this->shndx_);
5237       gold_assert(poris != NULL);
5238       section_start = poris->address();
5239       section_size = convert_to_section_size_type(poris->data_size());
5240     }
5241
5242   // We always append this to the end of an EXIDX section.
5243   Arm_address output_address = section_start + section_size;
5244
5245   // Write out the entry.  The first word either points to the beginning
5246   // or after the end of a text section.  The second word is the special
5247   // EXIDX_CANTUNWIND value.
5248   uint32_t prel31_offset = output_address - this->address();
5249   if (Bits<31>::has_overflow32(offset))
5250     gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5251   elfcpp::Swap_unaligned<32, big_endian>::writeval(oview,
5252                                                    prel31_offset & 0x7fffffffU);
5253   elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4,
5254                                                    elfcpp::EXIDX_CANTUNWIND);
5255
5256   of->write_output_view(this->offset(), oview_size, oview);
5257 }
5258
5259 // Arm_exidx_merged_section methods.
5260
5261 // Constructor for Arm_exidx_merged_section.
5262 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5263 // SECTION_OFFSET_MAP points to a section offset map describing how
5264 // parts of the input section are mapped to output.  DELETED_BYTES is
5265 // the number of bytes deleted from the EXIDX input section.
5266
5267 Arm_exidx_merged_section::Arm_exidx_merged_section(
5268     const Arm_exidx_input_section& exidx_input_section,
5269     const Arm_exidx_section_offset_map& section_offset_map,
5270     uint32_t deleted_bytes)
5271   : Output_relaxed_input_section(exidx_input_section.relobj(),
5272                                  exidx_input_section.shndx(),
5273                                  exidx_input_section.addralign()),
5274     exidx_input_section_(exidx_input_section),
5275     section_offset_map_(section_offset_map)
5276 {
5277   // If we retain or discard the whole EXIDX input section,  we would
5278   // not be here.
5279   gold_assert(deleted_bytes != 0
5280               && deleted_bytes != this->exidx_input_section_.size());
5281
5282   // Fix size here so that we do not need to implement set_final_data_size.
5283   uint32_t size = exidx_input_section.size() - deleted_bytes;
5284   this->set_data_size(size);
5285   this->fix_data_size();
5286
5287   // Allocate buffer for section contents and build contents.
5288   this->section_contents_ = new unsigned char[size];
5289 }
5290
5291 // Build the contents of a merged EXIDX output section.
5292
5293 void
5294 Arm_exidx_merged_section::build_contents(
5295     const unsigned char* original_contents,
5296     section_size_type original_size)
5297 {
5298   // Go over spans of input offsets and write only those that are not
5299   // discarded.
5300   section_offset_type in_start = 0;
5301   section_offset_type out_start = 0;
5302   section_offset_type in_max =
5303     convert_types<section_offset_type>(original_size);
5304   section_offset_type out_max =
5305     convert_types<section_offset_type>(this->data_size());
5306   for (Arm_exidx_section_offset_map::const_iterator p =
5307         this->section_offset_map_.begin();
5308       p != this->section_offset_map_.end();
5309       ++p)
5310     {
5311       section_offset_type in_end = p->first;
5312       gold_assert(in_end >= in_start);
5313       section_offset_type out_end = p->second;
5314       size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5315       if (out_end != -1)
5316         {
5317           size_t out_chunk_size =
5318             convert_types<size_t>(out_end - out_start + 1);
5319
5320           gold_assert(out_chunk_size == in_chunk_size
5321                       && in_end < in_max && out_end < out_max);
5322
5323           memcpy(this->section_contents_ + out_start,
5324                  original_contents + in_start,
5325                  out_chunk_size);
5326           out_start += out_chunk_size;
5327         }
5328       in_start += in_chunk_size;
5329     }
5330 }
5331
5332 // Given an input OBJECT, an input section index SHNDX within that
5333 // object, and an OFFSET relative to the start of that input
5334 // section, return whether or not the corresponding offset within
5335 // the output section is known.  If this function returns true, it
5336 // sets *POUTPUT to the output offset.  The value -1 indicates that
5337 // this input offset is being discarded.
5338
5339 bool
5340 Arm_exidx_merged_section::do_output_offset(
5341     const Relobj* relobj,
5342     unsigned int shndx,
5343     section_offset_type offset,
5344     section_offset_type* poutput) const
5345 {
5346   // We only handle offsets for the original EXIDX input section.
5347   if (relobj != this->exidx_input_section_.relobj()
5348       || shndx != this->exidx_input_section_.shndx())
5349     return false;
5350
5351   section_offset_type section_size =
5352     convert_types<section_offset_type>(this->exidx_input_section_.size());
5353   if (offset < 0 || offset >= section_size)
5354     // Input offset is out of valid range.
5355     *poutput = -1;
5356   else
5357     {
5358       // We need to look up the section offset map to determine the output
5359       // offset.  Find the reference point in map that is first offset
5360       // bigger than or equal to this offset.
5361       Arm_exidx_section_offset_map::const_iterator p =
5362         this->section_offset_map_.lower_bound(offset);
5363
5364       // The section offset maps are build such that this should not happen if
5365       // input offset is in the valid range.
5366       gold_assert(p != this->section_offset_map_.end());
5367
5368       // We need to check if this is dropped.
5369      section_offset_type ref = p->first;
5370      section_offset_type mapped_ref = p->second;
5371
5372       if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5373         // Offset is present in output.
5374         *poutput = mapped_ref + (offset - ref);
5375       else
5376         // Offset is discarded owing to EXIDX entry merging.
5377         *poutput = -1;
5378     }
5379
5380   return true;
5381 }
5382
5383 // Write this to output file OF.
5384
5385 void
5386 Arm_exidx_merged_section::do_write(Output_file* of)
5387 {
5388   off_t offset = this->offset();
5389   const section_size_type oview_size = this->data_size();
5390   unsigned char* const oview = of->get_output_view(offset, oview_size);
5391
5392   Output_section* os = this->relobj()->output_section(this->shndx());
5393   gold_assert(os != NULL);
5394
5395   memcpy(oview, this->section_contents_, oview_size);
5396   of->write_output_view(this->offset(), oview_size, oview);
5397 }
5398
5399 // Arm_exidx_fixup methods.
5400
5401 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5402 // is not an EXIDX_CANTUNWIND entry already.  The new EXIDX_CANTUNWIND entry
5403 // points to the end of the last seen EXIDX section.
5404
5405 void
5406 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5407 {
5408   if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5409       && this->last_input_section_ != NULL)
5410     {
5411       Relobj* relobj = this->last_input_section_->relobj();
5412       unsigned int text_shndx = this->last_input_section_->link();
5413       Arm_exidx_cantunwind* cantunwind =
5414         new Arm_exidx_cantunwind(relobj, text_shndx);
5415       this->exidx_output_section_->add_output_section_data(cantunwind);
5416       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5417     }
5418 }
5419
5420 // Process an EXIDX section entry in input.  Return whether this entry
5421 // can be deleted in the output.  SECOND_WORD in the second word of the
5422 // EXIDX entry.
5423
5424 bool
5425 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5426 {
5427   bool delete_entry;
5428   if (second_word == elfcpp::EXIDX_CANTUNWIND)
5429     {
5430       // Merge if previous entry is also an EXIDX_CANTUNWIND.
5431       delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5432       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5433     }
5434   else if ((second_word & 0x80000000) != 0)
5435     {
5436       // Inlined unwinding data.  Merge if equal to previous.
5437       delete_entry = (merge_exidx_entries_
5438                       && this->last_unwind_type_ == UT_INLINED_ENTRY
5439                       && this->last_inlined_entry_ == second_word);
5440       this->last_unwind_type_ = UT_INLINED_ENTRY;
5441       this->last_inlined_entry_ = second_word;
5442     }
5443   else
5444     {
5445       // Normal table entry.  In theory we could merge these too,
5446       // but duplicate entries are likely to be much less common.
5447       delete_entry = false;
5448       this->last_unwind_type_ = UT_NORMAL_ENTRY;
5449     }
5450   return delete_entry;
5451 }
5452
5453 // Update the current section offset map during EXIDX section fix-up.
5454 // If there is no map, create one.  INPUT_OFFSET is the offset of a
5455 // reference point, DELETED_BYTES is the number of deleted by in the
5456 // section so far.  If DELETE_ENTRY is true, the reference point and
5457 // all offsets after the previous reference point are discarded.
5458
5459 void
5460 Arm_exidx_fixup::update_offset_map(
5461     section_offset_type input_offset,
5462     section_size_type deleted_bytes,
5463     bool delete_entry)
5464 {
5465   if (this->section_offset_map_ == NULL)
5466     this->section_offset_map_ = new Arm_exidx_section_offset_map();
5467   section_offset_type output_offset;
5468   if (delete_entry)
5469     output_offset = Arm_exidx_input_section::invalid_offset;
5470   else
5471     output_offset = input_offset - deleted_bytes;
5472   (*this->section_offset_map_)[input_offset] = output_offset;
5473 }
5474
5475 // Process EXIDX_INPUT_SECTION for EXIDX entry merging.  Return the number of
5476 // bytes deleted.  SECTION_CONTENTS points to the contents of the EXIDX
5477 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5478 // If some entries are merged, also store a pointer to a newly created
5479 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP.  The caller
5480 // owns the map and is responsible for releasing it after use.
5481
5482 template<bool big_endian>
5483 uint32_t
5484 Arm_exidx_fixup::process_exidx_section(
5485     const Arm_exidx_input_section* exidx_input_section,
5486     const unsigned char* section_contents,
5487     section_size_type section_size,
5488     Arm_exidx_section_offset_map** psection_offset_map)
5489 {
5490   Relobj* relobj = exidx_input_section->relobj();
5491   unsigned shndx = exidx_input_section->shndx();
5492
5493   if ((section_size % 8) != 0)
5494     {
5495       // Something is wrong with this section.  Better not touch it.
5496       gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5497                  relobj->name().c_str(), shndx);
5498       this->last_input_section_ = exidx_input_section;
5499       this->last_unwind_type_ = UT_NONE;
5500       return 0;
5501     }
5502
5503   uint32_t deleted_bytes = 0;
5504   bool prev_delete_entry = false;
5505   gold_assert(this->section_offset_map_ == NULL);
5506
5507   for (section_size_type i = 0; i < section_size; i += 8)
5508     {
5509       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5510       const Valtype* wv =
5511           reinterpret_cast<const Valtype*>(section_contents + i + 4);
5512       uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5513
5514       bool delete_entry = this->process_exidx_entry(second_word);
5515
5516       // Entry deletion causes changes in output offsets.  We use a std::map
5517       // to record these.  And entry (x, y) means input offset x
5518       // is mapped to output offset y.  If y is invalid_offset, then x is
5519       // dropped in the output.  Because of the way std::map::lower_bound
5520       // works, we record the last offset in a region w.r.t to keeping or
5521       // dropping.  If there is no entry (x0, y0) for an input offset x0,
5522       // the output offset y0 of it is determined by the output offset y1 of
5523       // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5524       // in the map.  If y1 is not -1, then y0 = y1 + x0 - x1.  Otherwise, y1
5525       // y0 is also -1.
5526       if (delete_entry != prev_delete_entry && i != 0)
5527         this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5528
5529       // Update total deleted bytes for this entry.
5530       if (delete_entry)
5531         deleted_bytes += 8;
5532
5533       prev_delete_entry = delete_entry;
5534     }
5535
5536   // If section offset map is not NULL, make an entry for the end of
5537   // section.
5538   if (this->section_offset_map_ != NULL)
5539     update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5540
5541   *psection_offset_map = this->section_offset_map_;
5542   this->section_offset_map_ = NULL;
5543   this->last_input_section_ = exidx_input_section;
5544
5545   // Set the first output text section so that we can link the EXIDX output
5546   // section to it.  Ignore any EXIDX input section that is completely merged.
5547   if (this->first_output_text_section_ == NULL
5548       && deleted_bytes != section_size)
5549     {
5550       unsigned int link = exidx_input_section->link();
5551       Output_section* os = relobj->output_section(link);
5552       gold_assert(os != NULL);
5553       this->first_output_text_section_ = os;
5554     }
5555
5556   return deleted_bytes;
5557 }
5558
5559 // Arm_output_section methods.
5560
5561 // Create a stub group for input sections from BEGIN to END.  OWNER
5562 // points to the input section to be the owner a new stub table.
5563
5564 template<bool big_endian>
5565 void
5566 Arm_output_section<big_endian>::create_stub_group(
5567   Input_section_list::const_iterator begin,
5568   Input_section_list::const_iterator end,
5569   Input_section_list::const_iterator owner,
5570   Target_arm<big_endian>* target,
5571   std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5572   const Task* task)
5573 {
5574   // We use a different kind of relaxed section in an EXIDX section.
5575   // The static casting from Output_relaxed_input_section to
5576   // Arm_input_section is invalid in an EXIDX section.  We are okay
5577   // because we should not be calling this for an EXIDX section.
5578   gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5579
5580   // Currently we convert ordinary input sections into relaxed sections only
5581   // at this point but we may want to support creating relaxed input section
5582   // very early.  So we check here to see if owner is already a relaxed
5583   // section.
5584
5585   Arm_input_section<big_endian>* arm_input_section;
5586   if (owner->is_relaxed_input_section())
5587     {
5588       arm_input_section =
5589         Arm_input_section<big_endian>::as_arm_input_section(
5590           owner->relaxed_input_section());
5591     }
5592   else
5593     {
5594       gold_assert(owner->is_input_section());
5595       // Create a new relaxed input section.  We need to lock the original
5596       // file.
5597       Task_lock_obj<Object> tl(task, owner->relobj());
5598       arm_input_section =
5599         target->new_arm_input_section(owner->relobj(), owner->shndx());
5600       new_relaxed_sections->push_back(arm_input_section);
5601     }
5602
5603   // Create a stub table.
5604   Stub_table<big_endian>* stub_table =
5605     target->new_stub_table(arm_input_section);
5606
5607   arm_input_section->set_stub_table(stub_table);
5608
5609   Input_section_list::const_iterator p = begin;
5610   Input_section_list::const_iterator prev_p;
5611
5612   // Look for input sections or relaxed input sections in [begin ... end].
5613   do
5614     {
5615       if (p->is_input_section() || p->is_relaxed_input_section())
5616         {
5617           // The stub table information for input sections live
5618           // in their objects.
5619           Arm_relobj<big_endian>* arm_relobj =
5620             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5621           arm_relobj->set_stub_table(p->shndx(), stub_table);
5622         }
5623       prev_p = p++;
5624     }
5625   while (prev_p != end);
5626 }
5627
5628 // Group input sections for stub generation.  GROUP_SIZE is roughly the limit
5629 // of stub groups.  We grow a stub group by adding input section until the
5630 // size is just below GROUP_SIZE.  The last input section will be converted
5631 // into a stub table.  If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5632 // input section after the stub table, effectively double the group size.
5633 //
5634 // This is similar to the group_sections() function in elf32-arm.c but is
5635 // implemented differently.
5636
5637 template<bool big_endian>
5638 void
5639 Arm_output_section<big_endian>::group_sections(
5640     section_size_type group_size,
5641     bool stubs_always_after_branch,
5642     Target_arm<big_endian>* target,
5643     const Task* task)
5644 {
5645   // We only care about sections containing code.
5646   if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
5647     return;
5648
5649   // States for grouping.
5650   typedef enum
5651   {
5652     // No group is being built.
5653     NO_GROUP,
5654     // A group is being built but the stub table is not found yet.
5655     // We keep group a stub group until the size is just under GROUP_SIZE.
5656     // The last input section in the group will be used as the stub table.
5657     FINDING_STUB_SECTION,
5658     // A group is being built and we have already found a stub table.
5659     // We enter this state to grow a stub group by adding input section
5660     // after the stub table.  This effectively doubles the group size.
5661     HAS_STUB_SECTION
5662   } State;
5663
5664   // Any newly created relaxed sections are stored here.
5665   std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5666
5667   State state = NO_GROUP;
5668   section_size_type off = 0;
5669   section_size_type group_begin_offset = 0;
5670   section_size_type group_end_offset = 0;
5671   section_size_type stub_table_end_offset = 0;
5672   Input_section_list::const_iterator group_begin =
5673     this->input_sections().end();
5674   Input_section_list::const_iterator stub_table =
5675     this->input_sections().end();
5676   Input_section_list::const_iterator group_end = this->input_sections().end();
5677   for (Input_section_list::const_iterator p = this->input_sections().begin();
5678        p != this->input_sections().end();
5679        ++p)
5680     {
5681       section_size_type section_begin_offset =
5682         align_address(off, p->addralign());
5683       section_size_type section_end_offset =
5684         section_begin_offset + p->data_size();
5685
5686       // Check to see if we should group the previously seen sections.
5687       switch (state)
5688         {
5689         case NO_GROUP:
5690           break;
5691
5692         case FINDING_STUB_SECTION:
5693           // Adding this section makes the group larger than GROUP_SIZE.
5694           if (section_end_offset - group_begin_offset >= group_size)
5695             {
5696               if (stubs_always_after_branch)
5697                 {
5698                   gold_assert(group_end != this->input_sections().end());
5699                   this->create_stub_group(group_begin, group_end, group_end,
5700                                           target, &new_relaxed_sections,
5701                                           task);
5702                   state = NO_GROUP;
5703                 }
5704               else
5705                 {
5706                   // But wait, there's more!  Input sections up to
5707                   // stub_group_size bytes after the stub table can be
5708                   // handled by it too.
5709                   state = HAS_STUB_SECTION;
5710                   stub_table = group_end;
5711                   stub_table_end_offset = group_end_offset;
5712                 }
5713             }
5714             break;
5715
5716         case HAS_STUB_SECTION:
5717           // Adding this section makes the post stub-section group larger
5718           // than GROUP_SIZE.
5719           if (section_end_offset - stub_table_end_offset >= group_size)
5720            {
5721              gold_assert(group_end != this->input_sections().end());
5722              this->create_stub_group(group_begin, group_end, stub_table,
5723                                      target, &new_relaxed_sections, task);
5724              state = NO_GROUP;
5725            }
5726            break;
5727
5728           default:
5729             gold_unreachable();
5730         }
5731
5732       // If we see an input section and currently there is no group, start
5733       // a new one.  Skip any empty sections.  We look at the data size
5734       // instead of calling p->relobj()->section_size() to avoid locking.
5735       if ((p->is_input_section() || p->is_relaxed_input_section())
5736           && (p->data_size() != 0))
5737         {
5738           if (state == NO_GROUP)
5739             {
5740               state = FINDING_STUB_SECTION;
5741               group_begin = p;
5742               group_begin_offset = section_begin_offset;
5743             }
5744
5745           // Keep track of the last input section seen.
5746           group_end = p;
5747           group_end_offset = section_end_offset;
5748         }
5749
5750       off = section_end_offset;
5751     }
5752
5753   // Create a stub group for any ungrouped sections.
5754   if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5755     {
5756       gold_assert(group_end != this->input_sections().end());
5757       this->create_stub_group(group_begin, group_end,
5758                               (state == FINDING_STUB_SECTION
5759                                ? group_end
5760                                : stub_table),
5761                                target, &new_relaxed_sections, task);
5762     }
5763
5764   // Convert input section into relaxed input section in a batch.
5765   if (!new_relaxed_sections.empty())
5766     this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5767
5768   // Update the section offsets
5769   for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5770     {
5771       Arm_relobj<big_endian>* arm_relobj =
5772         Arm_relobj<big_endian>::as_arm_relobj(
5773           new_relaxed_sections[i]->relobj());
5774       unsigned int shndx = new_relaxed_sections[i]->shndx();
5775       // Tell Arm_relobj that this input section is converted.
5776       arm_relobj->convert_input_section_to_relaxed_section(shndx);
5777     }
5778 }
5779
5780 // Append non empty text sections in this to LIST in ascending
5781 // order of their position in this.
5782
5783 template<bool big_endian>
5784 void
5785 Arm_output_section<big_endian>::append_text_sections_to_list(
5786     Text_section_list* list)
5787 {
5788   gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5789
5790   for (Input_section_list::const_iterator p = this->input_sections().begin();
5791        p != this->input_sections().end();
5792        ++p)
5793     {
5794       // We only care about plain or relaxed input sections.  We also
5795       // ignore any merged sections.
5796       if (p->is_input_section() || p->is_relaxed_input_section())
5797         list->push_back(Text_section_list::value_type(p->relobj(),
5798                                                       p->shndx()));
5799     }
5800 }
5801
5802 template<bool big_endian>
5803 void
5804 Arm_output_section<big_endian>::fix_exidx_coverage(
5805     Layout* layout,
5806     const Text_section_list& sorted_text_sections,
5807     Symbol_table* symtab,
5808     bool merge_exidx_entries,
5809     const Task* task)
5810 {
5811   // We should only do this for the EXIDX output section.
5812   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5813
5814   // We don't want the relaxation loop to undo these changes, so we discard
5815   // the current saved states and take another one after the fix-up.
5816   this->discard_states();
5817
5818   // Remove all input sections.
5819   uint64_t address = this->address();
5820   typedef std::list<Output_section::Input_section> Input_section_list;
5821   Input_section_list input_sections;
5822   this->reset_address_and_file_offset();
5823   this->get_input_sections(address, std::string(""), &input_sections);
5824
5825   if (!this->input_sections().empty())
5826     gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5827
5828   // Go through all the known input sections and record them.
5829   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5830   typedef Unordered_map<Section_id, const Output_section::Input_section*,
5831                         Section_id_hash> Text_to_exidx_map;
5832   Text_to_exidx_map text_to_exidx_map;
5833   for (Input_section_list::const_iterator p = input_sections.begin();
5834        p != input_sections.end();
5835        ++p)
5836     {
5837       // This should never happen.  At this point, we should only see
5838       // plain EXIDX input sections.
5839       gold_assert(!p->is_relaxed_input_section());
5840       text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5841     }
5842
5843   Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5844
5845   // Go over the sorted text sections.
5846   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5847   Section_id_set processed_input_sections;
5848   for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5849        p != sorted_text_sections.end();
5850        ++p)
5851     {
5852       Relobj* relobj = p->first;
5853       unsigned int shndx = p->second;
5854
5855       Arm_relobj<big_endian>* arm_relobj =
5856          Arm_relobj<big_endian>::as_arm_relobj(relobj);
5857       const Arm_exidx_input_section* exidx_input_section =
5858          arm_relobj->exidx_input_section_by_link(shndx);
5859
5860       // If this text section has no EXIDX section or if the EXIDX section
5861       // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5862       // of the last seen EXIDX section.
5863       if (exidx_input_section == NULL || exidx_input_section->has_errors())
5864         {
5865           exidx_fixup.add_exidx_cantunwind_as_needed();
5866           continue;
5867         }
5868
5869       Relobj* exidx_relobj = exidx_input_section->relobj();
5870       unsigned int exidx_shndx = exidx_input_section->shndx();
5871       Section_id sid(exidx_relobj, exidx_shndx);
5872       Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5873       if (iter == text_to_exidx_map.end())
5874         {
5875           // This is odd.  We have not seen this EXIDX input section before.
5876           // We cannot do fix-up.  If we saw a SECTIONS clause in a script,
5877           // issue a warning instead.  We assume the user knows what he
5878           // or she is doing.  Otherwise, this is an error.
5879           if (layout->script_options()->saw_sections_clause())
5880             gold_warning(_("unwinding may not work because EXIDX input section"
5881                            " %u of %s is not in EXIDX output section"),
5882                          exidx_shndx, exidx_relobj->name().c_str());
5883           else
5884             gold_error(_("unwinding may not work because EXIDX input section"
5885                          " %u of %s is not in EXIDX output section"),
5886                        exidx_shndx, exidx_relobj->name().c_str());
5887
5888           exidx_fixup.add_exidx_cantunwind_as_needed();
5889           continue;
5890         }
5891
5892       // We need to access the contents of the EXIDX section, lock the
5893       // object here.
5894       Task_lock_obj<Object> tl(task, exidx_relobj);
5895       section_size_type exidx_size;
5896       const unsigned char* exidx_contents =
5897         exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5898
5899       // Fix up coverage and append input section to output data list.
5900       Arm_exidx_section_offset_map* section_offset_map = NULL;
5901       uint32_t deleted_bytes =
5902         exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5903                                                       exidx_contents,
5904                                                       exidx_size,
5905                                                       &section_offset_map);
5906
5907       if (deleted_bytes == exidx_input_section->size())
5908         {
5909           // The whole EXIDX section got merged.  Remove it from output.
5910           gold_assert(section_offset_map == NULL);
5911           exidx_relobj->set_output_section(exidx_shndx, NULL);
5912
5913           // All local symbols defined in this input section will be dropped.
5914           // We need to adjust output local symbol count.
5915           arm_relobj->set_output_local_symbol_count_needs_update();
5916         }
5917       else if (deleted_bytes > 0)
5918         {
5919           // Some entries are merged.  We need to convert this EXIDX input
5920           // section into a relaxed section.
5921           gold_assert(section_offset_map != NULL);
5922
5923           Arm_exidx_merged_section* merged_section =
5924             new Arm_exidx_merged_section(*exidx_input_section,
5925                                          *section_offset_map, deleted_bytes);
5926           merged_section->build_contents(exidx_contents, exidx_size);
5927
5928           const std::string secname = exidx_relobj->section_name(exidx_shndx);
5929           this->add_relaxed_input_section(layout, merged_section, secname);
5930           arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5931
5932           // All local symbols defined in discarded portions of this input
5933           // section will be dropped.  We need to adjust output local symbol
5934           // count.
5935           arm_relobj->set_output_local_symbol_count_needs_update();
5936         }
5937       else
5938         {
5939           // Just add back the EXIDX input section.
5940           gold_assert(section_offset_map == NULL);
5941           const Output_section::Input_section* pis = iter->second;
5942           gold_assert(pis->is_input_section());
5943           this->add_script_input_section(*pis);
5944         }
5945
5946       processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5947     }
5948
5949   // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5950   exidx_fixup.add_exidx_cantunwind_as_needed();
5951
5952   // Remove any known EXIDX input sections that are not processed.
5953   for (Input_section_list::const_iterator p = input_sections.begin();
5954        p != input_sections.end();
5955        ++p)
5956     {
5957       if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5958           == processed_input_sections.end())
5959         {
5960           // We discard a known EXIDX section because its linked
5961           // text section has been folded by ICF.  We also discard an
5962           // EXIDX section with error, the output does not matter in this
5963           // case.  We do this to avoid triggering asserts.
5964           Arm_relobj<big_endian>* arm_relobj =
5965             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5966           const Arm_exidx_input_section* exidx_input_section =
5967             arm_relobj->exidx_input_section_by_shndx(p->shndx());
5968           gold_assert(exidx_input_section != NULL);
5969           if (!exidx_input_section->has_errors())
5970             {
5971               unsigned int text_shndx = exidx_input_section->link();
5972               gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5973             }
5974
5975           // Remove this from link.  We also need to recount the
5976           // local symbols.
5977           p->relobj()->set_output_section(p->shndx(), NULL);
5978           arm_relobj->set_output_local_symbol_count_needs_update();
5979         }
5980     }
5981
5982   // Link exidx output section to the first seen output section and
5983   // set correct entry size.
5984   this->set_link_section(exidx_fixup.first_output_text_section());
5985   this->set_entsize(8);
5986
5987   // Make changes permanent.
5988   this->save_states();
5989   this->set_section_offsets_need_adjustment();
5990 }
5991
5992 // Link EXIDX output sections to text output sections.
5993
5994 template<bool big_endian>
5995 void
5996 Arm_output_section<big_endian>::set_exidx_section_link()
5997 {
5998   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5999   if (!this->input_sections().empty())
6000     {
6001       Input_section_list::const_iterator p = this->input_sections().begin();
6002       Arm_relobj<big_endian>* arm_relobj =
6003         Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6004       unsigned exidx_shndx = p->shndx();
6005       const Arm_exidx_input_section* exidx_input_section =
6006         arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6007       gold_assert(exidx_input_section != NULL);
6008       unsigned int text_shndx = exidx_input_section->link();
6009       Output_section* os = arm_relobj->output_section(text_shndx);
6010       this->set_link_section(os);
6011     }
6012 }
6013
6014 // Arm_relobj methods.
6015
6016 // Determine if an input section is scannable for stub processing.  SHDR is
6017 // the header of the section and SHNDX is the section index.  OS is the output
6018 // section for the input section and SYMTAB is the global symbol table used to
6019 // look up ICF information.
6020
6021 template<bool big_endian>
6022 bool
6023 Arm_relobj<big_endian>::section_is_scannable(
6024     const elfcpp::Shdr<32, big_endian>& shdr,
6025     unsigned int shndx,
6026     const Output_section* os,
6027     const Symbol_table* symtab)
6028 {
6029   // Skip any empty sections, unallocated sections or sections whose
6030   // type are not SHT_PROGBITS.
6031   if (shdr.get_sh_size() == 0
6032       || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6033       || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6034     return false;
6035
6036   // Skip any discarded or ICF'ed sections.
6037   if (os == NULL || symtab->is_section_folded(this, shndx))
6038     return false;
6039
6040   // If this requires special offset handling, check to see if it is
6041   // a relaxed section.  If this is not, then it is a merged section that
6042   // we cannot handle.
6043   if (this->is_output_section_offset_invalid(shndx))
6044     {
6045       const Output_relaxed_input_section* poris =
6046         os->find_relaxed_input_section(this, shndx);
6047       if (poris == NULL)
6048         return false;
6049     }
6050
6051   return true;
6052 }
6053
6054 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6055 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6056
6057 template<bool big_endian>
6058 bool
6059 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6060     const elfcpp::Shdr<32, big_endian>& shdr,
6061     const Relobj::Output_sections& out_sections,
6062     const Symbol_table* symtab,
6063     const unsigned char* pshdrs)
6064 {
6065   unsigned int sh_type = shdr.get_sh_type();
6066   if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6067     return false;
6068
6069   // Ignore empty section.
6070   off_t sh_size = shdr.get_sh_size();
6071   if (sh_size == 0)
6072     return false;
6073
6074   // Ignore reloc section with unexpected symbol table.  The
6075   // error will be reported in the final link.
6076   if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6077     return false;
6078
6079   unsigned int reloc_size;
6080   if (sh_type == elfcpp::SHT_REL)
6081     reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6082   else
6083     reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6084
6085   // Ignore reloc section with unexpected entsize or uneven size.
6086   // The error will be reported in the final link.
6087   if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6088     return false;
6089
6090   // Ignore reloc section with bad info.  This error will be
6091   // reported in the final link.
6092   unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6093   if (index >= this->shnum())
6094     return false;
6095
6096   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6097   const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6098   return this->section_is_scannable(text_shdr, index,
6099                                    out_sections[index], symtab);
6100 }
6101
6102 // Return the output address of either a plain input section or a relaxed
6103 // input section.  SHNDX is the section index.  We define and use this
6104 // instead of calling Output_section::output_address because that is slow
6105 // for large output.
6106
6107 template<bool big_endian>
6108 Arm_address
6109 Arm_relobj<big_endian>::simple_input_section_output_address(
6110     unsigned int shndx,
6111     Output_section* os)
6112 {
6113   if (this->is_output_section_offset_invalid(shndx))
6114     {
6115       const Output_relaxed_input_section* poris =
6116         os->find_relaxed_input_section(this, shndx);
6117       // We do not handle merged sections here.
6118       gold_assert(poris != NULL);
6119       return poris->address();
6120     }
6121   else
6122     return os->address() + this->get_output_section_offset(shndx);
6123 }
6124
6125 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6126 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6127
6128 template<bool big_endian>
6129 bool
6130 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6131     const elfcpp::Shdr<32, big_endian>& shdr,
6132     unsigned int shndx,
6133     Output_section* os,
6134     const Symbol_table* symtab)
6135 {
6136   if (!this->section_is_scannable(shdr, shndx, os, symtab))
6137     return false;
6138
6139   // If the section does not cross any 4K-boundaries, it does not need to
6140   // be scanned.
6141   Arm_address address = this->simple_input_section_output_address(shndx, os);
6142   if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6143     return false;
6144
6145   return true;
6146 }
6147
6148 // Scan a section for Cortex-A8 workaround.
6149
6150 template<bool big_endian>
6151 void
6152 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6153     const elfcpp::Shdr<32, big_endian>& shdr,
6154     unsigned int shndx,
6155     Output_section* os,
6156     Target_arm<big_endian>* arm_target)
6157 {
6158   // Look for the first mapping symbol in this section.  It should be
6159   // at (shndx, 0).
6160   Mapping_symbol_position section_start(shndx, 0);
6161   typename Mapping_symbols_info::const_iterator p =
6162     this->mapping_symbols_info_.lower_bound(section_start);
6163
6164   // There are no mapping symbols for this section.  Treat it as a data-only
6165   // section.  Issue a warning if section is marked as containing
6166   // instructions.
6167   if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6168     {
6169       if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6170         gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6171                        "erratum because it has no mapping symbols."),
6172                      shndx, this->name().c_str());
6173       return;
6174     }
6175
6176   Arm_address output_address =
6177     this->simple_input_section_output_address(shndx, os);
6178
6179   // Get the section contents.
6180   section_size_type input_view_size = 0;
6181   const unsigned char* input_view =
6182     this->section_contents(shndx, &input_view_size, false);
6183
6184   // We need to go through the mapping symbols to determine what to
6185   // scan.  There are two reasons.  First, we should look at THUMB code and
6186   // THUMB code only.  Second, we only want to look at the 4K-page boundary
6187   // to speed up the scanning.
6188
6189   while (p != this->mapping_symbols_info_.end()
6190         && p->first.first == shndx)
6191     {
6192       typename Mapping_symbols_info::const_iterator next =
6193         this->mapping_symbols_info_.upper_bound(p->first);
6194
6195       // Only scan part of a section with THUMB code.
6196       if (p->second == 't')
6197         {
6198           // Determine the end of this range.
6199           section_size_type span_start =
6200             convert_to_section_size_type(p->first.second);
6201           section_size_type span_end;
6202           if (next != this->mapping_symbols_info_.end()
6203               && next->first.first == shndx)
6204             span_end = convert_to_section_size_type(next->first.second);
6205           else
6206             span_end = convert_to_section_size_type(shdr.get_sh_size());
6207
6208           if (((span_start + output_address) & ~0xfffUL)
6209               != ((span_end + output_address - 1) & ~0xfffUL))
6210             {
6211               arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6212                                                           span_start, span_end,
6213                                                           input_view,
6214                                                           output_address);
6215             }
6216         }
6217
6218       p = next;
6219     }
6220 }
6221
6222 // Scan relocations for stub generation.
6223
6224 template<bool big_endian>
6225 void
6226 Arm_relobj<big_endian>::scan_sections_for_stubs(
6227     Target_arm<big_endian>* arm_target,
6228     const Symbol_table* symtab,
6229     const Layout* layout)
6230 {
6231   unsigned int shnum = this->shnum();
6232   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6233
6234   // Read the section headers.
6235   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6236                                                shnum * shdr_size,
6237                                                true, true);
6238
6239   // To speed up processing, we set up hash tables for fast lookup of
6240   // input offsets to output addresses.
6241   this->initialize_input_to_output_maps();
6242
6243   const Relobj::Output_sections& out_sections(this->output_sections());
6244
6245   Relocate_info<32, big_endian> relinfo;
6246   relinfo.symtab = symtab;
6247   relinfo.layout = layout;
6248   relinfo.object = this;
6249
6250   // Do relocation stubs scanning.
6251   const unsigned char* p = pshdrs + shdr_size;
6252   for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6253     {
6254       const elfcpp::Shdr<32, big_endian> shdr(p);
6255       if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6256                                                   pshdrs))
6257         {
6258           unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6259           Arm_address output_offset = this->get_output_section_offset(index);
6260           Arm_address output_address;
6261           if (output_offset != invalid_address)
6262             output_address = out_sections[index]->address() + output_offset;
6263           else
6264             {
6265               // Currently this only happens for a relaxed section.
6266               const Output_relaxed_input_section* poris =
6267               out_sections[index]->find_relaxed_input_section(this, index);
6268               gold_assert(poris != NULL);
6269               output_address = poris->address();
6270             }
6271
6272           // Get the relocations.
6273           const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6274                                                         shdr.get_sh_size(),
6275                                                         true, false);
6276
6277           // Get the section contents.  This does work for the case in which
6278           // we modify the contents of an input section.  We need to pass the
6279           // output view under such circumstances.
6280           section_size_type input_view_size = 0;
6281           const unsigned char* input_view =
6282             this->section_contents(index, &input_view_size, false);
6283
6284           relinfo.reloc_shndx = i;
6285           relinfo.data_shndx = index;
6286           unsigned int sh_type = shdr.get_sh_type();
6287           unsigned int reloc_size;
6288           if (sh_type == elfcpp::SHT_REL)
6289             reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6290           else
6291             reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6292
6293           Output_section* os = out_sections[index];
6294           arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6295                                              shdr.get_sh_size() / reloc_size,
6296                                              os,
6297                                              output_offset == invalid_address,
6298                                              input_view, output_address,
6299                                              input_view_size);
6300         }
6301     }
6302
6303   // Do Cortex-A8 erratum stubs scanning.  This has to be done for a section
6304   // after its relocation section, if there is one, is processed for
6305   // relocation stubs.  Merging this loop with the one above would have been
6306   // complicated since we would have had to make sure that relocation stub
6307   // scanning is done first.
6308   if (arm_target->fix_cortex_a8())
6309     {
6310       const unsigned char* p = pshdrs + shdr_size;
6311       for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6312         {
6313           const elfcpp::Shdr<32, big_endian> shdr(p);
6314           if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6315                                                           out_sections[i],
6316                                                           symtab))
6317             this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6318                                                      arm_target);
6319         }
6320     }
6321
6322   // After we've done the relocations, we release the hash tables,
6323   // since we no longer need them.
6324   this->free_input_to_output_maps();
6325 }
6326
6327 // Count the local symbols.  The ARM backend needs to know if a symbol
6328 // is a THUMB function or not.  For global symbols, it is easy because
6329 // the Symbol object keeps the ELF symbol type.  For local symbol it is
6330 // harder because we cannot access this information.   So we override the
6331 // do_count_local_symbol in parent and scan local symbols to mark
6332 // THUMB functions.  This is not the most efficient way but I do not want to
6333 // slow down other ports by calling a per symbol target hook inside
6334 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6335
6336 template<bool big_endian>
6337 void
6338 Arm_relobj<big_endian>::do_count_local_symbols(
6339     Stringpool_template<char>* pool,
6340     Stringpool_template<char>* dynpool)
6341 {
6342   // We need to fix-up the values of any local symbols whose type are
6343   // STT_ARM_TFUNC.
6344
6345   // Ask parent to count the local symbols.
6346   Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6347   const unsigned int loccount = this->local_symbol_count();
6348   if (loccount == 0)
6349     return;
6350
6351   // Initialize the thumb function bit-vector.
6352   std::vector<bool> empty_vector(loccount, false);
6353   this->local_symbol_is_thumb_function_.swap(empty_vector);
6354
6355   // Read the symbol table section header.
6356   const unsigned int symtab_shndx = this->symtab_shndx();
6357   elfcpp::Shdr<32, big_endian>
6358       symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6359   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6360
6361   // Read the local symbols.
6362   const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6363   gold_assert(loccount == symtabshdr.get_sh_info());
6364   off_t locsize = loccount * sym_size;
6365   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6366                                               locsize, true, true);
6367
6368   // For mapping symbol processing, we need to read the symbol names.
6369   unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6370   if (strtab_shndx >= this->shnum())
6371     {
6372       this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6373       return;
6374     }
6375
6376   elfcpp::Shdr<32, big_endian>
6377     strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6378   if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6379     {
6380       this->error(_("symbol table name section has wrong type: %u"),
6381                   static_cast<unsigned int>(strtabshdr.get_sh_type()));
6382       return;
6383     }
6384   const char* pnames =
6385     reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6386                                                  strtabshdr.get_sh_size(),
6387                                                  false, false));
6388
6389   // Loop over the local symbols and mark any local symbols pointing
6390   // to THUMB functions.
6391
6392   // Skip the first dummy symbol.
6393   psyms += sym_size;
6394   typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6395     this->local_values();
6396   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6397     {
6398       elfcpp::Sym<32, big_endian> sym(psyms);
6399       elfcpp::STT st_type = sym.get_st_type();
6400       Symbol_value<32>& lv((*plocal_values)[i]);
6401       Arm_address input_value = lv.input_value();
6402
6403       // Check to see if this is a mapping symbol.
6404       const char* sym_name = pnames + sym.get_st_name();
6405       if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6406         {
6407           bool is_ordinary;
6408           unsigned int input_shndx =
6409             this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6410           gold_assert(is_ordinary);
6411
6412           // Strip of LSB in case this is a THUMB symbol.
6413           Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6414           this->mapping_symbols_info_[msp] = sym_name[1];
6415         }
6416
6417       if (st_type == elfcpp::STT_ARM_TFUNC
6418           || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6419         {
6420           // This is a THUMB function.  Mark this and canonicalize the
6421           // symbol value by setting LSB.
6422           this->local_symbol_is_thumb_function_[i] = true;
6423           if ((input_value & 1) == 0)
6424             lv.set_input_value(input_value | 1);
6425         }
6426     }
6427 }
6428
6429 // Relocate sections.
6430 template<bool big_endian>
6431 void
6432 Arm_relobj<big_endian>::do_relocate_sections(
6433     const Symbol_table* symtab,
6434     const Layout* layout,
6435     const unsigned char* pshdrs,
6436     Output_file* of,
6437     typename Sized_relobj_file<32, big_endian>::Views* pviews)
6438 {
6439   // Call parent to relocate sections.
6440   Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6441                                                           pshdrs, of, pviews);
6442
6443   // We do not generate stubs if doing a relocatable link.
6444   if (parameters->options().relocatable())
6445     return;
6446
6447   // Relocate stub tables.
6448   unsigned int shnum = this->shnum();
6449
6450   Target_arm<big_endian>* arm_target =
6451     Target_arm<big_endian>::default_target();
6452
6453   Relocate_info<32, big_endian> relinfo;
6454   relinfo.symtab = symtab;
6455   relinfo.layout = layout;
6456   relinfo.object = this;
6457
6458   for (unsigned int i = 1; i < shnum; ++i)
6459     {
6460       Arm_input_section<big_endian>* arm_input_section =
6461         arm_target->find_arm_input_section(this, i);
6462
6463       if (arm_input_section != NULL
6464           && arm_input_section->is_stub_table_owner()
6465           && !arm_input_section->stub_table()->empty())
6466         {
6467           // We cannot discard a section if it owns a stub table.
6468           Output_section* os = this->output_section(i);
6469           gold_assert(os != NULL);
6470
6471           relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6472           relinfo.reloc_shdr = NULL;
6473           relinfo.data_shndx = i;
6474           relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6475
6476           gold_assert((*pviews)[i].view != NULL);
6477
6478           // We are passed the output section view.  Adjust it to cover the
6479           // stub table only.
6480           Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6481           gold_assert((stub_table->address() >= (*pviews)[i].address)
6482                       && ((stub_table->address() + stub_table->data_size())
6483                           <= (*pviews)[i].address + (*pviews)[i].view_size));
6484
6485           off_t offset = stub_table->address() - (*pviews)[i].address;
6486           unsigned char* view = (*pviews)[i].view + offset;
6487           Arm_address address = stub_table->address();
6488           section_size_type view_size = stub_table->data_size();
6489
6490           stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6491                                      view_size);
6492         }
6493
6494       // Apply Cortex A8 workaround if applicable.
6495       if (this->section_has_cortex_a8_workaround(i))
6496         {
6497           unsigned char* view = (*pviews)[i].view;
6498           Arm_address view_address = (*pviews)[i].address;
6499           section_size_type view_size = (*pviews)[i].view_size;
6500           Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6501
6502           // Adjust view to cover section.
6503           Output_section* os = this->output_section(i);
6504           gold_assert(os != NULL);
6505           Arm_address section_address =
6506             this->simple_input_section_output_address(i, os);
6507           uint64_t section_size = this->section_size(i);
6508
6509           gold_assert(section_address >= view_address
6510                       && ((section_address + section_size)
6511                           <= (view_address + view_size)));
6512
6513           unsigned char* section_view = view + (section_address - view_address);
6514
6515           // Apply the Cortex-A8 workaround to the output address range
6516           // corresponding to this input section.
6517           stub_table->apply_cortex_a8_workaround_to_address_range(
6518               arm_target,
6519               section_view,
6520               section_address,
6521               section_size);
6522         }
6523     }
6524 }
6525
6526 // Find the linked text section of an EXIDX section by looking at the first
6527 // relocation.  4.4.1 of the EHABI specifications says that an EXIDX section
6528 // must be linked to its associated code section via the sh_link field of
6529 // its section header.  However, some tools are broken and the link is not
6530 // always set.  LD just drops such an EXIDX section silently, causing the
6531 // associated code not unwindabled.   Here we try a little bit harder to
6532 // discover the linked code section.
6533 //
6534 // PSHDR points to the section header of a relocation section of an EXIDX
6535 // section.  If we can find a linked text section, return true and
6536 // store the text section index in the location PSHNDX.  Otherwise
6537 // return false.
6538
6539 template<bool big_endian>
6540 bool
6541 Arm_relobj<big_endian>::find_linked_text_section(
6542     const unsigned char* pshdr,
6543     const unsigned char* psyms,
6544     unsigned int* pshndx)
6545 {
6546   elfcpp::Shdr<32, big_endian> shdr(pshdr);
6547
6548   // If there is no relocation, we cannot find the linked text section.
6549   size_t reloc_size;
6550   if (shdr.get_sh_type() == elfcpp::SHT_REL)
6551       reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6552   else
6553       reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6554   size_t reloc_count = shdr.get_sh_size() / reloc_size;
6555
6556   // Get the relocations.
6557   const unsigned char* prelocs =
6558       this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6559
6560   // Find the REL31 relocation for the first word of the first EXIDX entry.
6561   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6562     {
6563       Arm_address r_offset;
6564       typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6565       if (shdr.get_sh_type() == elfcpp::SHT_REL)
6566         {
6567           typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6568           r_info = reloc.get_r_info();
6569           r_offset = reloc.get_r_offset();
6570         }
6571       else
6572         {
6573           typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6574           r_info = reloc.get_r_info();
6575           r_offset = reloc.get_r_offset();
6576         }
6577
6578       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6579       if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6580         continue;
6581
6582       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6583       if (r_sym == 0
6584           || r_sym >= this->local_symbol_count()
6585           || r_offset != 0)
6586         continue;
6587
6588       // This is the relocation for the first word of the first EXIDX entry.
6589       // We expect to see a local section symbol.
6590       const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6591       elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6592       if (sym.get_st_type() == elfcpp::STT_SECTION)
6593         {
6594           bool is_ordinary;
6595           *pshndx =
6596             this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6597           gold_assert(is_ordinary);
6598           return true;
6599         }
6600       else
6601         return false;
6602     }
6603
6604   return false;
6605 }
6606
6607 // Make an EXIDX input section object for an EXIDX section whose index is
6608 // SHNDX.  SHDR is the section header of the EXIDX section and TEXT_SHNDX
6609 // is the section index of the linked text section.
6610
6611 template<bool big_endian>
6612 void
6613 Arm_relobj<big_endian>::make_exidx_input_section(
6614     unsigned int shndx,
6615     const elfcpp::Shdr<32, big_endian>& shdr,
6616     unsigned int text_shndx,
6617     const elfcpp::Shdr<32, big_endian>& text_shdr)
6618 {
6619   // Create an Arm_exidx_input_section object for this EXIDX section.
6620   Arm_exidx_input_section* exidx_input_section =
6621     new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6622                                 shdr.get_sh_addralign(),
6623                                 text_shdr.get_sh_size());
6624
6625   gold_assert(this->exidx_section_map_[shndx] == NULL);
6626   this->exidx_section_map_[shndx] = exidx_input_section;
6627
6628   if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6629     {
6630       gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6631                  this->section_name(shndx).c_str(), shndx, text_shndx,
6632                  this->name().c_str());
6633       exidx_input_section->set_has_errors();
6634     }
6635   else if (this->exidx_section_map_[text_shndx] != NULL)
6636     {
6637       unsigned other_exidx_shndx =
6638         this->exidx_section_map_[text_shndx]->shndx();
6639       gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6640                    "%s(%u) in %s"),
6641                  this->section_name(shndx).c_str(), shndx,
6642                  this->section_name(other_exidx_shndx).c_str(),
6643                  other_exidx_shndx, this->section_name(text_shndx).c_str(),
6644                  text_shndx, this->name().c_str());
6645       exidx_input_section->set_has_errors();
6646     }
6647   else
6648      this->exidx_section_map_[text_shndx] = exidx_input_section;
6649
6650   // Check section flags of text section.
6651   if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6652     {
6653       gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6654                    " in %s"),
6655                  this->section_name(shndx).c_str(), shndx,
6656                  this->section_name(text_shndx).c_str(), text_shndx,
6657                  this->name().c_str());
6658       exidx_input_section->set_has_errors();
6659     }
6660   else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6661     // I would like to make this an error but currently ld just ignores
6662     // this.
6663     gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6664                    "%s(%u) in %s"),
6665                  this->section_name(shndx).c_str(), shndx,
6666                  this->section_name(text_shndx).c_str(), text_shndx,
6667                  this->name().c_str());
6668 }
6669
6670 // Read the symbol information.
6671
6672 template<bool big_endian>
6673 void
6674 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6675 {
6676   // Call parent class to read symbol information.
6677   Sized_relobj_file<32, big_endian>::do_read_symbols(sd);
6678
6679   // If this input file is a binary file, it has no processor
6680   // specific flags and attributes section.
6681   Input_file::Format format = this->input_file()->format();
6682   if (format != Input_file::FORMAT_ELF)
6683     {
6684       gold_assert(format == Input_file::FORMAT_BINARY);
6685       this->merge_flags_and_attributes_ = false;
6686       return;
6687     }
6688
6689   // Read processor-specific flags in ELF file header.
6690   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6691                                               elfcpp::Elf_sizes<32>::ehdr_size,
6692                                               true, false);
6693   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6694   this->processor_specific_flags_ = ehdr.get_e_flags();
6695
6696   // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6697   // sections.
6698   std::vector<unsigned int> deferred_exidx_sections;
6699   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6700   const unsigned char* pshdrs = sd->section_headers->data();
6701   const unsigned char* ps = pshdrs + shdr_size;
6702   bool must_merge_flags_and_attributes = false;
6703   for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6704     {
6705       elfcpp::Shdr<32, big_endian> shdr(ps);
6706
6707       // Sometimes an object has no contents except the section name string
6708       // table and an empty symbol table with the undefined symbol.  We
6709       // don't want to merge processor-specific flags from such an object.
6710       if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6711         {
6712           // Symbol table is not empty.
6713           const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6714              elfcpp::Elf_sizes<32>::sym_size;
6715           if (shdr.get_sh_size() > sym_size)
6716             must_merge_flags_and_attributes = true;
6717         }
6718       else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6719         // If this is neither an empty symbol table nor a string table,
6720         // be conservative.
6721         must_merge_flags_and_attributes = true;
6722
6723       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6724         {
6725           gold_assert(this->attributes_section_data_ == NULL);
6726           section_offset_type section_offset = shdr.get_sh_offset();
6727           section_size_type section_size =
6728             convert_to_section_size_type(shdr.get_sh_size());
6729           const unsigned char* view =
6730              this->get_view(section_offset, section_size, true, false);
6731           this->attributes_section_data_ =
6732             new Attributes_section_data(view, section_size);
6733         }
6734       else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6735         {
6736           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6737           if (text_shndx == elfcpp::SHN_UNDEF)
6738             deferred_exidx_sections.push_back(i);
6739           else
6740             {
6741               elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6742                                                      + text_shndx * shdr_size);
6743               this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6744             }
6745           // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6746           if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6747             gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6748                          this->section_name(i).c_str(), this->name().c_str());
6749         }
6750     }
6751
6752   // This is rare.
6753   if (!must_merge_flags_and_attributes)
6754     {
6755       gold_assert(deferred_exidx_sections.empty());
6756       this->merge_flags_and_attributes_ = false;
6757       return;
6758     }
6759
6760   // Some tools are broken and they do not set the link of EXIDX sections.
6761   // We look at the first relocation to figure out the linked sections.
6762   if (!deferred_exidx_sections.empty())
6763     {
6764       // We need to go over the section headers again to find the mapping
6765       // from sections being relocated to their relocation sections.  This is
6766       // a bit inefficient as we could do that in the loop above.  However,
6767       // we do not expect any deferred EXIDX sections normally.  So we do not
6768       // want to slow down the most common path.
6769       typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6770       Reloc_map reloc_map;
6771       ps = pshdrs + shdr_size;
6772       for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6773         {
6774           elfcpp::Shdr<32, big_endian> shdr(ps);
6775           elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6776           if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6777             {
6778               unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6779               if (info_shndx >= this->shnum())
6780                 gold_error(_("relocation section %u has invalid info %u"),
6781                            i, info_shndx);
6782               Reloc_map::value_type value(info_shndx, i);
6783               std::pair<Reloc_map::iterator, bool> result =
6784                 reloc_map.insert(value);
6785               if (!result.second)
6786                 gold_error(_("section %u has multiple relocation sections "
6787                              "%u and %u"),
6788                            info_shndx, i, reloc_map[info_shndx]);
6789             }
6790         }
6791
6792       // Read the symbol table section header.
6793       const unsigned int symtab_shndx = this->symtab_shndx();
6794       elfcpp::Shdr<32, big_endian>
6795           symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6796       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6797
6798       // Read the local symbols.
6799       const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6800       const unsigned int loccount = this->local_symbol_count();
6801       gold_assert(loccount == symtabshdr.get_sh_info());
6802       off_t locsize = loccount * sym_size;
6803       const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6804                                                   locsize, true, true);
6805
6806       // Process the deferred EXIDX sections.
6807       for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6808         {
6809           unsigned int shndx = deferred_exidx_sections[i];
6810           elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6811           unsigned int text_shndx = elfcpp::SHN_UNDEF;
6812           Reloc_map::const_iterator it = reloc_map.find(shndx);
6813           if (it != reloc_map.end())
6814             find_linked_text_section(pshdrs + it->second * shdr_size,
6815                                      psyms, &text_shndx);
6816           elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6817                                                  + text_shndx * shdr_size);
6818           this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6819         }
6820     }
6821 }
6822
6823 // Process relocations for garbage collection.  The ARM target uses .ARM.exidx
6824 // sections for unwinding.  These sections are referenced implicitly by
6825 // text sections linked in the section headers.  If we ignore these implicit
6826 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6827 // will be garbage-collected incorrectly.  Hence we override the same function
6828 // in the base class to handle these implicit references.
6829
6830 template<bool big_endian>
6831 void
6832 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6833                                              Layout* layout,
6834                                              Read_relocs_data* rd)
6835 {
6836   // First, call base class method to process relocations in this object.
6837   Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6838
6839   // If --gc-sections is not specified, there is nothing more to do.
6840   // This happens when --icf is used but --gc-sections is not.
6841   if (!parameters->options().gc_sections())
6842     return;
6843
6844   unsigned int shnum = this->shnum();
6845   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6846   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6847                                                shnum * shdr_size,
6848                                                true, true);
6849
6850   // Scan section headers for sections of type SHT_ARM_EXIDX.  Add references
6851   // to these from the linked text sections.
6852   const unsigned char* ps = pshdrs + shdr_size;
6853   for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6854     {
6855       elfcpp::Shdr<32, big_endian> shdr(ps);
6856       if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6857         {
6858           // Found an .ARM.exidx section, add it to the set of reachable
6859           // sections from its linked text section.
6860           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6861           symtab->gc()->add_reference(this, text_shndx, this, i);
6862         }
6863     }
6864 }
6865
6866 // Update output local symbol count.  Owing to EXIDX entry merging, some local
6867 // symbols  will be removed in output.  Adjust output local symbol count
6868 // accordingly.  We can only changed the static output local symbol count.  It
6869 // is too late to change the dynamic symbols.
6870
6871 template<bool big_endian>
6872 void
6873 Arm_relobj<big_endian>::update_output_local_symbol_count()
6874 {
6875   // Caller should check that this needs updating.  We want caller checking
6876   // because output_local_symbol_count_needs_update() is most likely inlined.
6877   gold_assert(this->output_local_symbol_count_needs_update_);
6878
6879   gold_assert(this->symtab_shndx() != -1U);
6880   if (this->symtab_shndx() == 0)
6881     {
6882       // This object has no symbols.  Weird but legal.
6883       return;
6884     }
6885
6886   // Read the symbol table section header.
6887   const unsigned int symtab_shndx = this->symtab_shndx();
6888   elfcpp::Shdr<32, big_endian>
6889     symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6890   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6891
6892   // Read the local symbols.
6893   const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6894   const unsigned int loccount = this->local_symbol_count();
6895   gold_assert(loccount == symtabshdr.get_sh_info());
6896   off_t locsize = loccount * sym_size;
6897   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6898                                               locsize, true, true);
6899
6900   // Loop over the local symbols.
6901
6902   typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6903      Output_sections;
6904   const Output_sections& out_sections(this->output_sections());
6905   unsigned int shnum = this->shnum();
6906   unsigned int count = 0;
6907   // Skip the first, dummy, symbol.
6908   psyms += sym_size;
6909   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6910     {
6911       elfcpp::Sym<32, big_endian> sym(psyms);
6912
6913       Symbol_value<32>& lv((*this->local_values())[i]);
6914
6915       // This local symbol was already discarded by do_count_local_symbols.
6916       if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6917         continue;
6918
6919       bool is_ordinary;
6920       unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6921                                                   &is_ordinary);
6922
6923       if (shndx < shnum)
6924         {
6925           Output_section* os = out_sections[shndx];
6926
6927           // This local symbol no longer has an output section.  Discard it.
6928           if (os == NULL)
6929             {
6930               lv.set_no_output_symtab_entry();
6931               continue;
6932             }
6933
6934           // Currently we only discard parts of EXIDX input sections.
6935           // We explicitly check for a merged EXIDX input section to avoid
6936           // calling Output_section_data::output_offset unless necessary.
6937           if ((this->get_output_section_offset(shndx) == invalid_address)
6938               && (this->exidx_input_section_by_shndx(shndx) != NULL))
6939             {
6940               section_offset_type output_offset =
6941                 os->output_offset(this, shndx, lv.input_value());
6942               if (output_offset == -1)
6943                 {
6944                   // This symbol is defined in a part of an EXIDX input section
6945                   // that is discarded due to entry merging.
6946                   lv.set_no_output_symtab_entry();
6947                   continue;
6948                 }
6949             }
6950         }
6951
6952       ++count;
6953     }
6954
6955   this->set_output_local_symbol_count(count);
6956   this->output_local_symbol_count_needs_update_ = false;
6957 }
6958
6959 // Arm_dynobj methods.
6960
6961 // Read the symbol information.
6962
6963 template<bool big_endian>
6964 void
6965 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6966 {
6967   // Call parent class to read symbol information.
6968   Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6969
6970   // Read processor-specific flags in ELF file header.
6971   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6972                                               elfcpp::Elf_sizes<32>::ehdr_size,
6973                                               true, false);
6974   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6975   this->processor_specific_flags_ = ehdr.get_e_flags();
6976
6977   // Read the attributes section if there is one.
6978   // We read from the end because gas seems to put it near the end of
6979   // the section headers.
6980   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6981   const unsigned char* ps =
6982     sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6983   for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6984     {
6985       elfcpp::Shdr<32, big_endian> shdr(ps);
6986       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6987         {
6988           section_offset_type section_offset = shdr.get_sh_offset();
6989           section_size_type section_size =
6990             convert_to_section_size_type(shdr.get_sh_size());
6991           const unsigned char* view =
6992             this->get_view(section_offset, section_size, true, false);
6993           this->attributes_section_data_ =
6994             new Attributes_section_data(view, section_size);
6995           break;
6996         }
6997     }
6998 }
6999
7000 // Stub_addend_reader methods.
7001
7002 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7003
7004 template<bool big_endian>
7005 elfcpp::Elf_types<32>::Elf_Swxword
7006 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7007     unsigned int r_type,
7008     const unsigned char* view,
7009     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7010 {
7011   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
7012
7013   switch (r_type)
7014     {
7015     case elfcpp::R_ARM_CALL:
7016     case elfcpp::R_ARM_JUMP24:
7017     case elfcpp::R_ARM_PLT32:
7018       {
7019         typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7020         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7021         Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7022         return Bits<26>::sign_extend32(val << 2);
7023       }
7024
7025     case elfcpp::R_ARM_THM_CALL:
7026     case elfcpp::R_ARM_THM_JUMP24:
7027     case elfcpp::R_ARM_THM_XPC22:
7028       {
7029         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7030         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7031         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7032         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7033         return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7034       }
7035
7036     case elfcpp::R_ARM_THM_JUMP19:
7037       {
7038         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7039         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7040         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7041         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7042         return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7043       }
7044
7045     default:
7046       gold_unreachable();
7047     }
7048 }
7049
7050 // Arm_output_data_got methods.
7051
7052 // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
7053 // The first one is initialized to be 1, which is the module index for
7054 // the main executable and the second one 0.  A reloc of the type
7055 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7056 // be applied by gold.  GSYM is a global symbol.
7057 //
7058 template<bool big_endian>
7059 void
7060 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7061     unsigned int got_type,
7062     Symbol* gsym)
7063 {
7064   if (gsym->has_got_offset(got_type))
7065     return;
7066
7067   // We are doing a static link.  Just mark it as belong to module 1,
7068   // the executable.
7069   unsigned int got_offset = this->add_constant(1);
7070   gsym->set_got_offset(got_type, got_offset);
7071   got_offset = this->add_constant(0);
7072   this->static_relocs_.push_back(Static_reloc(got_offset,
7073                                               elfcpp::R_ARM_TLS_DTPOFF32,
7074                                               gsym));
7075 }
7076
7077 // Same as the above but for a local symbol.
7078
7079 template<bool big_endian>
7080 void
7081 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7082   unsigned int got_type,
7083   Sized_relobj_file<32, big_endian>* object,
7084   unsigned int index)
7085 {
7086   if (object->local_has_got_offset(index, got_type))
7087     return;
7088
7089   // We are doing a static link.  Just mark it as belong to module 1,
7090   // the executable.
7091   unsigned int got_offset = this->add_constant(1);
7092   object->set_local_got_offset(index, got_type, got_offset);
7093   got_offset = this->add_constant(0);
7094   this->static_relocs_.push_back(Static_reloc(got_offset,
7095                                               elfcpp::R_ARM_TLS_DTPOFF32,
7096                                               object, index));
7097 }
7098
7099 template<bool big_endian>
7100 void
7101 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7102 {
7103   // Call parent to write out GOT.
7104   Output_data_got<32, big_endian>::do_write(of);
7105
7106   // We are done if there is no fix up.
7107   if (this->static_relocs_.empty())
7108     return;
7109
7110   gold_assert(parameters->doing_static_link());
7111
7112   const off_t offset = this->offset();
7113   const section_size_type oview_size =
7114     convert_to_section_size_type(this->data_size());
7115   unsigned char* const oview = of->get_output_view(offset, oview_size);
7116
7117   Output_segment* tls_segment = this->layout_->tls_segment();
7118   gold_assert(tls_segment != NULL);
7119
7120   // The thread pointer $tp points to the TCB, which is followed by the
7121   // TLS.  So we need to adjust $tp relative addressing by this amount.
7122   Arm_address aligned_tcb_size =
7123     align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7124
7125   for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7126     {
7127       Static_reloc& reloc(this->static_relocs_[i]);
7128
7129       Arm_address value;
7130       if (!reloc.symbol_is_global())
7131         {
7132           Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7133           const Symbol_value<32>* psymval =
7134             reloc.relobj()->local_symbol(reloc.index());
7135
7136           // We are doing static linking.  Issue an error and skip this
7137           // relocation if the symbol is undefined or in a discarded_section.
7138           bool is_ordinary;
7139           unsigned int shndx = psymval->input_shndx(&is_ordinary);
7140           if ((shndx == elfcpp::SHN_UNDEF)
7141               || (is_ordinary
7142                   && shndx != elfcpp::SHN_UNDEF
7143                   && !object->is_section_included(shndx)
7144                   && !this->symbol_table_->is_section_folded(object, shndx)))
7145             {
7146               gold_error(_("undefined or discarded local symbol %u from "
7147                            " object %s in GOT"),
7148                          reloc.index(), reloc.relobj()->name().c_str());
7149               continue;
7150             }
7151
7152           value = psymval->value(object, 0);
7153         }
7154       else
7155         {
7156           const Symbol* gsym = reloc.symbol();
7157           gold_assert(gsym != NULL);
7158           if (gsym->is_forwarder())
7159             gsym = this->symbol_table_->resolve_forwards(gsym);
7160
7161           // We are doing static linking.  Issue an error and skip this
7162           // relocation if the symbol is undefined or in a discarded_section
7163           // unless it is a weakly_undefined symbol.
7164           if ((gsym->is_defined_in_discarded_section()
7165                || gsym->is_undefined())
7166               && !gsym->is_weak_undefined())
7167             {
7168               gold_error(_("undefined or discarded symbol %s in GOT"),
7169                          gsym->name());
7170               continue;
7171             }
7172
7173           if (!gsym->is_weak_undefined())
7174             {
7175               const Sized_symbol<32>* sym =
7176                 static_cast<const Sized_symbol<32>*>(gsym);
7177               value = sym->value();
7178             }
7179           else
7180               value = 0;
7181         }
7182
7183       unsigned got_offset = reloc.got_offset();
7184       gold_assert(got_offset < oview_size);
7185
7186       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7187       Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7188       Valtype x;
7189       switch (reloc.r_type())
7190         {
7191         case elfcpp::R_ARM_TLS_DTPOFF32:
7192           x = value;
7193           break;
7194         case elfcpp::R_ARM_TLS_TPOFF32:
7195           x = value + aligned_tcb_size;
7196           break;
7197         default:
7198           gold_unreachable();
7199         }
7200       elfcpp::Swap<32, big_endian>::writeval(wv, x);
7201     }
7202
7203   of->write_output_view(offset, oview_size, oview);
7204 }
7205
7206 // A class to handle the PLT data.
7207 // This is an abstract base class that handles most of the linker details
7208 // but does not know the actual contents of PLT entries.  The derived
7209 // classes below fill in those details.
7210
7211 template<bool big_endian>
7212 class Output_data_plt_arm : public Output_section_data
7213 {
7214  public:
7215   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7216     Reloc_section;
7217
7218   Output_data_plt_arm(Layout*, uint64_t addralign, Output_data_space*);
7219
7220   // Add an entry to the PLT.
7221   void
7222   add_entry(Symbol* gsym);
7223
7224   // Return the .rel.plt section data.
7225   const Reloc_section*
7226   rel_plt() const
7227   { return this->rel_; }
7228
7229   // Return the number of PLT entries.
7230   unsigned int
7231   entry_count() const
7232   { return this->count_; }
7233
7234   // Return the offset of the first non-reserved PLT entry.
7235   unsigned int
7236   first_plt_entry_offset() const
7237   { return this->do_first_plt_entry_offset(); }
7238
7239   // Return the size of a PLT entry.
7240   unsigned int
7241   get_plt_entry_size() const
7242   { return this->do_get_plt_entry_size(); }
7243
7244  protected:
7245   // Fill in the first PLT entry.
7246   void
7247   fill_first_plt_entry(unsigned char* pov,
7248                        Arm_address got_address,
7249                        Arm_address plt_address)
7250   { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
7251
7252   void
7253   fill_plt_entry(unsigned char* pov,
7254                  Arm_address got_address,
7255                  Arm_address plt_address,
7256                  unsigned int got_offset,
7257                  unsigned int plt_offset)
7258   { do_fill_plt_entry(pov, got_address, plt_address, got_offset, plt_offset); }
7259
7260   virtual unsigned int
7261   do_first_plt_entry_offset() const = 0;
7262
7263   virtual unsigned int
7264   do_get_plt_entry_size() const = 0;
7265
7266   virtual void
7267   do_fill_first_plt_entry(unsigned char* pov,
7268                           Arm_address got_address,
7269                           Arm_address plt_address) = 0;
7270
7271   virtual void
7272   do_fill_plt_entry(unsigned char* pov,
7273                     Arm_address got_address,
7274                     Arm_address plt_address,
7275                     unsigned int got_offset,
7276                     unsigned int plt_offset) = 0;
7277
7278   void
7279   do_adjust_output_section(Output_section* os);
7280
7281   // Write to a map file.
7282   void
7283   do_print_to_mapfile(Mapfile* mapfile) const
7284   { mapfile->print_output_data(this, _("** PLT")); }
7285
7286  private:
7287   // Set the final size.
7288   void
7289   set_final_data_size()
7290   {
7291     this->set_data_size(this->first_plt_entry_offset()
7292                         + this->count_ * this->get_plt_entry_size());
7293   }
7294
7295   // Write out the PLT data.
7296   void
7297   do_write(Output_file*);
7298
7299   // The reloc section.
7300   Reloc_section* rel_;
7301   // The .got.plt section.
7302   Output_data_space* got_plt_;
7303   // The number of PLT entries.
7304   unsigned int count_;
7305 };
7306
7307 // Create the PLT section.  The ordinary .got section is an argument,
7308 // since we need to refer to the start.  We also create our own .got
7309 // section just for PLT entries.
7310
7311 template<bool big_endian>
7312 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7313                                                      uint64_t addralign,
7314                                                      Output_data_space* got_plt)
7315   : Output_section_data(addralign), got_plt_(got_plt), count_(0)
7316 {
7317   this->rel_ = new Reloc_section(false);
7318   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7319                                   elfcpp::SHF_ALLOC, this->rel_,
7320                                   ORDER_DYNAMIC_PLT_RELOCS, false);
7321 }
7322
7323 template<bool big_endian>
7324 void
7325 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7326 {
7327   os->set_entsize(0);
7328 }
7329
7330 // Add an entry to the PLT.
7331
7332 template<bool big_endian>
7333 void
7334 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7335 {
7336   gold_assert(!gsym->has_plt_offset());
7337
7338   // Note that when setting the PLT offset we skip the initial
7339   // reserved PLT entry.
7340   gsym->set_plt_offset((this->count_) * this->get_plt_entry_size()
7341                        + this->first_plt_entry_offset());
7342
7343   ++this->count_;
7344
7345   section_offset_type got_offset = this->got_plt_->current_data_size();
7346
7347   // Every PLT entry needs a GOT entry which points back to the PLT
7348   // entry (this will be changed by the dynamic linker, normally
7349   // lazily when the function is called).
7350   this->got_plt_->set_current_data_size(got_offset + 4);
7351
7352   // Every PLT entry needs a reloc.
7353   gsym->set_needs_dynsym_entry();
7354   this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7355                          got_offset);
7356
7357   // Note that we don't need to save the symbol.  The contents of the
7358   // PLT are independent of which symbols are used.  The symbols only
7359   // appear in the relocations.
7360 }
7361
7362 template<bool big_endian>
7363 class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
7364 {
7365  public:
7366   Output_data_plt_arm_standard(Layout* layout, Output_data_space* got_plt)
7367     : Output_data_plt_arm<big_endian>(layout, 4, got_plt)
7368   { }
7369
7370  protected:
7371   // Return the offset of the first non-reserved PLT entry.
7372   virtual unsigned int
7373   do_first_plt_entry_offset() const
7374   { return sizeof(first_plt_entry); }
7375
7376   // Return the size of a PLT entry.
7377   virtual unsigned int
7378   do_get_plt_entry_size() const
7379   { return sizeof(plt_entry); }
7380
7381   virtual void
7382   do_fill_first_plt_entry(unsigned char* pov,
7383                           Arm_address got_address,
7384                           Arm_address plt_address);
7385
7386   virtual void
7387   do_fill_plt_entry(unsigned char* pov,
7388                     Arm_address got_address,
7389                     Arm_address plt_address,
7390                     unsigned int got_offset,
7391                     unsigned int plt_offset);
7392
7393  private:
7394   // Template for the first PLT entry.
7395   static const uint32_t first_plt_entry[5];
7396
7397   // Template for subsequent PLT entries.
7398   static const uint32_t plt_entry[3];
7399 };
7400
7401 // ARM PLTs.
7402 // FIXME:  This is not very flexible.  Right now this has only been tested
7403 // on armv5te.  If we are to support additional architecture features like
7404 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7405
7406 // The first entry in the PLT.
7407 template<bool big_endian>
7408 const uint32_t Output_data_plt_arm_standard<big_endian>::first_plt_entry[5] =
7409 {
7410   0xe52de004,   // str   lr, [sp, #-4]!
7411   0xe59fe004,   // ldr   lr, [pc, #4]
7412   0xe08fe00e,   // add   lr, pc, lr
7413   0xe5bef008,   // ldr   pc, [lr, #8]!
7414   0x00000000,   // &GOT[0] - .
7415 };
7416
7417 template<bool big_endian>
7418 void
7419 Output_data_plt_arm_standard<big_endian>::do_fill_first_plt_entry(
7420     unsigned char* pov,
7421     Arm_address got_address,
7422     Arm_address plt_address)
7423 {
7424   // Write first PLT entry.  All but the last word are constants.
7425   const size_t num_first_plt_words = (sizeof(first_plt_entry)
7426                                       / sizeof(plt_entry[0]));
7427   for (size_t i = 0; i < num_first_plt_words - 1; i++)
7428     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7429   // Last word in first PLT entry is &GOT[0] - .
7430   elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7431                                          got_address - (plt_address + 16));
7432 }
7433
7434 // Subsequent entries in the PLT.
7435
7436 template<bool big_endian>
7437 const uint32_t Output_data_plt_arm_standard<big_endian>::plt_entry[3] =
7438 {
7439   0xe28fc600,   // add   ip, pc, #0xNN00000
7440   0xe28cca00,   // add   ip, ip, #0xNN000
7441   0xe5bcf000,   // ldr   pc, [ip, #0xNNN]!
7442 };
7443
7444 template<bool big_endian>
7445 void
7446 Output_data_plt_arm_standard<big_endian>::do_fill_plt_entry(
7447     unsigned char* pov,
7448     Arm_address got_address,
7449     Arm_address plt_address,
7450     unsigned int got_offset,
7451     unsigned int plt_offset)
7452 {
7453   int32_t offset = ((got_address + got_offset)
7454                     - (plt_address + plt_offset + 8));
7455
7456   gold_assert(offset >= 0 && offset < 0x0fffffff);
7457   uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7458   elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7459   uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7460   elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7461   uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7462   elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7463 }
7464
7465 // Write out the PLT.  This uses the hand-coded instructions above,
7466 // and adjusts them as needed.  This is all specified by the arm ELF
7467 // Processor Supplement.
7468
7469 template<bool big_endian>
7470 void
7471 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7472 {
7473   const off_t offset = this->offset();
7474   const section_size_type oview_size =
7475     convert_to_section_size_type(this->data_size());
7476   unsigned char* const oview = of->get_output_view(offset, oview_size);
7477
7478   const off_t got_file_offset = this->got_plt_->offset();
7479   const section_size_type got_size =
7480     convert_to_section_size_type(this->got_plt_->data_size());
7481   unsigned char* const got_view = of->get_output_view(got_file_offset,
7482                                                       got_size);
7483   unsigned char* pov = oview;
7484
7485   Arm_address plt_address = this->address();
7486   Arm_address got_address = this->got_plt_->address();
7487
7488   // Write first PLT entry.
7489   this->fill_first_plt_entry(pov, got_address, plt_address);
7490   pov += this->first_plt_entry_offset();
7491
7492   unsigned char* got_pov = got_view;
7493
7494   memset(got_pov, 0, 12);
7495   got_pov += 12;
7496
7497   unsigned int plt_offset = this->first_plt_entry_offset();
7498   unsigned int got_offset = 12;
7499   const unsigned int count = this->count_;
7500   for (unsigned int i = 0;
7501        i < count;
7502        ++i,
7503          pov += this->get_plt_entry_size(),
7504          got_pov += 4,
7505          plt_offset += this->get_plt_entry_size(),
7506          got_offset += 4)
7507     {
7508       // Set and adjust the PLT entry itself.
7509       this->fill_plt_entry(pov, got_address, plt_address,
7510                            got_offset, plt_offset);
7511
7512       // Set the entry in the GOT.
7513       elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7514     }
7515
7516   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7517   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7518
7519   of->write_output_view(offset, oview_size, oview);
7520   of->write_output_view(got_file_offset, got_size, got_view);
7521 }
7522
7523 // Create a PLT entry for a global symbol.
7524
7525 template<bool big_endian>
7526 void
7527 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7528                                        Symbol* gsym)
7529 {
7530   if (gsym->has_plt_offset())
7531     return;
7532
7533   if (this->plt_ == NULL)
7534     {
7535       // Create the GOT sections first.
7536       this->got_section(symtab, layout);
7537
7538       this->plt_ = this->make_data_plt(layout, this->got_plt_);
7539
7540       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7541                                       (elfcpp::SHF_ALLOC
7542                                        | elfcpp::SHF_EXECINSTR),
7543                                       this->plt_, ORDER_PLT, false);
7544     }
7545   this->plt_->add_entry(gsym);
7546 }
7547
7548 // Return the number of entries in the PLT.
7549
7550 template<bool big_endian>
7551 unsigned int
7552 Target_arm<big_endian>::plt_entry_count() const
7553 {
7554   if (this->plt_ == NULL)
7555     return 0;
7556   return this->plt_->entry_count();
7557 }
7558
7559 // Return the offset of the first non-reserved PLT entry.
7560
7561 template<bool big_endian>
7562 unsigned int
7563 Target_arm<big_endian>::first_plt_entry_offset() const
7564 {
7565   return this->plt_->first_plt_entry_offset();
7566 }
7567
7568 // Return the size of each PLT entry.
7569
7570 template<bool big_endian>
7571 unsigned int
7572 Target_arm<big_endian>::plt_entry_size() const
7573 {
7574   return this->plt_->get_plt_entry_size();
7575 }
7576
7577 // Get the section to use for TLS_DESC relocations.
7578
7579 template<bool big_endian>
7580 typename Target_arm<big_endian>::Reloc_section*
7581 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7582 {
7583   return this->plt_section()->rel_tls_desc(layout);
7584 }
7585
7586 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7587
7588 template<bool big_endian>
7589 void
7590 Target_arm<big_endian>::define_tls_base_symbol(
7591     Symbol_table* symtab,
7592     Layout* layout)
7593 {
7594   if (this->tls_base_symbol_defined_)
7595     return;
7596
7597   Output_segment* tls_segment = layout->tls_segment();
7598   if (tls_segment != NULL)
7599     {
7600       bool is_exec = parameters->options().output_is_executable();
7601       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7602                                        Symbol_table::PREDEFINED,
7603                                        tls_segment, 0, 0,
7604                                        elfcpp::STT_TLS,
7605                                        elfcpp::STB_LOCAL,
7606                                        elfcpp::STV_HIDDEN, 0,
7607                                        (is_exec
7608                                         ? Symbol::SEGMENT_END
7609                                         : Symbol::SEGMENT_START),
7610                                        true);
7611     }
7612   this->tls_base_symbol_defined_ = true;
7613 }
7614
7615 // Create a GOT entry for the TLS module index.
7616
7617 template<bool big_endian>
7618 unsigned int
7619 Target_arm<big_endian>::got_mod_index_entry(
7620     Symbol_table* symtab,
7621     Layout* layout,
7622     Sized_relobj_file<32, big_endian>* object)
7623 {
7624   if (this->got_mod_index_offset_ == -1U)
7625     {
7626       gold_assert(symtab != NULL && layout != NULL && object != NULL);
7627       Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7628       unsigned int got_offset;
7629       if (!parameters->doing_static_link())
7630         {
7631           got_offset = got->add_constant(0);
7632           Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7633           rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7634                              got_offset);
7635         }
7636       else
7637         {
7638           // We are doing a static link.  Just mark it as belong to module 1,
7639           // the executable.
7640           got_offset = got->add_constant(1);
7641         }
7642
7643       got->add_constant(0);
7644       this->got_mod_index_offset_ = got_offset;
7645     }
7646   return this->got_mod_index_offset_;
7647 }
7648
7649 // Optimize the TLS relocation type based on what we know about the
7650 // symbol.  IS_FINAL is true if the final address of this symbol is
7651 // known at link time.
7652
7653 template<bool big_endian>
7654 tls::Tls_optimization
7655 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7656 {
7657   // FIXME: Currently we do not do any TLS optimization.
7658   return tls::TLSOPT_NONE;
7659 }
7660
7661 // Get the Reference_flags for a particular relocation.
7662
7663 template<bool big_endian>
7664 int
7665 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
7666 {
7667   switch (r_type)
7668     {
7669     case elfcpp::R_ARM_NONE:
7670     case elfcpp::R_ARM_V4BX:
7671     case elfcpp::R_ARM_GNU_VTENTRY:
7672     case elfcpp::R_ARM_GNU_VTINHERIT:
7673       // No symbol reference.
7674       return 0;
7675
7676     case elfcpp::R_ARM_ABS32:
7677     case elfcpp::R_ARM_ABS16:
7678     case elfcpp::R_ARM_ABS12:
7679     case elfcpp::R_ARM_THM_ABS5:
7680     case elfcpp::R_ARM_ABS8:
7681     case elfcpp::R_ARM_BASE_ABS:
7682     case elfcpp::R_ARM_MOVW_ABS_NC:
7683     case elfcpp::R_ARM_MOVT_ABS:
7684     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7685     case elfcpp::R_ARM_THM_MOVT_ABS:
7686     case elfcpp::R_ARM_ABS32_NOI:
7687       return Symbol::ABSOLUTE_REF;
7688
7689     case elfcpp::R_ARM_REL32:
7690     case elfcpp::R_ARM_LDR_PC_G0:
7691     case elfcpp::R_ARM_SBREL32:
7692     case elfcpp::R_ARM_THM_PC8:
7693     case elfcpp::R_ARM_BASE_PREL:
7694     case elfcpp::R_ARM_MOVW_PREL_NC:
7695     case elfcpp::R_ARM_MOVT_PREL:
7696     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7697     case elfcpp::R_ARM_THM_MOVT_PREL:
7698     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7699     case elfcpp::R_ARM_THM_PC12:
7700     case elfcpp::R_ARM_REL32_NOI:
7701     case elfcpp::R_ARM_ALU_PC_G0_NC:
7702     case elfcpp::R_ARM_ALU_PC_G0:
7703     case elfcpp::R_ARM_ALU_PC_G1_NC:
7704     case elfcpp::R_ARM_ALU_PC_G1:
7705     case elfcpp::R_ARM_ALU_PC_G2:
7706     case elfcpp::R_ARM_LDR_PC_G1:
7707     case elfcpp::R_ARM_LDR_PC_G2:
7708     case elfcpp::R_ARM_LDRS_PC_G0:
7709     case elfcpp::R_ARM_LDRS_PC_G1:
7710     case elfcpp::R_ARM_LDRS_PC_G2:
7711     case elfcpp::R_ARM_LDC_PC_G0:
7712     case elfcpp::R_ARM_LDC_PC_G1:
7713     case elfcpp::R_ARM_LDC_PC_G2:
7714     case elfcpp::R_ARM_ALU_SB_G0_NC:
7715     case elfcpp::R_ARM_ALU_SB_G0:
7716     case elfcpp::R_ARM_ALU_SB_G1_NC:
7717     case elfcpp::R_ARM_ALU_SB_G1:
7718     case elfcpp::R_ARM_ALU_SB_G2:
7719     case elfcpp::R_ARM_LDR_SB_G0:
7720     case elfcpp::R_ARM_LDR_SB_G1:
7721     case elfcpp::R_ARM_LDR_SB_G2:
7722     case elfcpp::R_ARM_LDRS_SB_G0:
7723     case elfcpp::R_ARM_LDRS_SB_G1:
7724     case elfcpp::R_ARM_LDRS_SB_G2:
7725     case elfcpp::R_ARM_LDC_SB_G0:
7726     case elfcpp::R_ARM_LDC_SB_G1:
7727     case elfcpp::R_ARM_LDC_SB_G2:
7728     case elfcpp::R_ARM_MOVW_BREL_NC:
7729     case elfcpp::R_ARM_MOVT_BREL:
7730     case elfcpp::R_ARM_MOVW_BREL:
7731     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7732     case elfcpp::R_ARM_THM_MOVT_BREL:
7733     case elfcpp::R_ARM_THM_MOVW_BREL:
7734     case elfcpp::R_ARM_GOTOFF32:
7735     case elfcpp::R_ARM_GOTOFF12:
7736     case elfcpp::R_ARM_SBREL31:
7737       return Symbol::RELATIVE_REF;
7738
7739     case elfcpp::R_ARM_PLT32:
7740     case elfcpp::R_ARM_CALL:
7741     case elfcpp::R_ARM_JUMP24:
7742     case elfcpp::R_ARM_THM_CALL:
7743     case elfcpp::R_ARM_THM_JUMP24:
7744     case elfcpp::R_ARM_THM_JUMP19:
7745     case elfcpp::R_ARM_THM_JUMP6:
7746     case elfcpp::R_ARM_THM_JUMP11:
7747     case elfcpp::R_ARM_THM_JUMP8:
7748     // R_ARM_PREL31 is not used to relocate call/jump instructions but
7749     // in unwind tables. It may point to functions via PLTs.
7750     // So we treat it like call/jump relocations above.
7751     case elfcpp::R_ARM_PREL31:
7752       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
7753
7754     case elfcpp::R_ARM_GOT_BREL:
7755     case elfcpp::R_ARM_GOT_ABS:
7756     case elfcpp::R_ARM_GOT_PREL:
7757       // Absolute in GOT.
7758       return Symbol::ABSOLUTE_REF;
7759
7760     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
7761     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
7762     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
7763     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
7764     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
7765       return Symbol::TLS_REF;
7766
7767     case elfcpp::R_ARM_TARGET1:
7768     case elfcpp::R_ARM_TARGET2:
7769     case elfcpp::R_ARM_COPY:
7770     case elfcpp::R_ARM_GLOB_DAT:
7771     case elfcpp::R_ARM_JUMP_SLOT:
7772     case elfcpp::R_ARM_RELATIVE:
7773     case elfcpp::R_ARM_PC24:
7774     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7775     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7776     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7777     default:
7778       // Not expected.  We will give an error later.
7779       return 0;
7780     }
7781 }
7782
7783 // Report an unsupported relocation against a local symbol.
7784
7785 template<bool big_endian>
7786 void
7787 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7788     Sized_relobj_file<32, big_endian>* object,
7789     unsigned int r_type)
7790 {
7791   gold_error(_("%s: unsupported reloc %u against local symbol"),
7792              object->name().c_str(), r_type);
7793 }
7794
7795 // We are about to emit a dynamic relocation of type R_TYPE.  If the
7796 // dynamic linker does not support it, issue an error.  The GNU linker
7797 // only issues a non-PIC error for an allocated read-only section.
7798 // Here we know the section is allocated, but we don't know that it is
7799 // read-only.  But we check for all the relocation types which the
7800 // glibc dynamic linker supports, so it seems appropriate to issue an
7801 // error even if the section is not read-only.
7802
7803 template<bool big_endian>
7804 void
7805 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7806                                             unsigned int r_type)
7807 {
7808   switch (r_type)
7809     {
7810     // These are the relocation types supported by glibc for ARM.
7811     case elfcpp::R_ARM_RELATIVE:
7812     case elfcpp::R_ARM_COPY:
7813     case elfcpp::R_ARM_GLOB_DAT:
7814     case elfcpp::R_ARM_JUMP_SLOT:
7815     case elfcpp::R_ARM_ABS32:
7816     case elfcpp::R_ARM_ABS32_NOI:
7817     case elfcpp::R_ARM_PC24:
7818     // FIXME: The following 3 types are not supported by Android's dynamic
7819     // linker.
7820     case elfcpp::R_ARM_TLS_DTPMOD32:
7821     case elfcpp::R_ARM_TLS_DTPOFF32:
7822     case elfcpp::R_ARM_TLS_TPOFF32:
7823       return;
7824
7825     default:
7826       {
7827         // This prevents us from issuing more than one error per reloc
7828         // section.  But we can still wind up issuing more than one
7829         // error per object file.
7830         if (this->issued_non_pic_error_)
7831           return;
7832         const Arm_reloc_property* reloc_property =
7833           arm_reloc_property_table->get_reloc_property(r_type);
7834         gold_assert(reloc_property != NULL);
7835         object->error(_("requires unsupported dynamic reloc %s; "
7836                       "recompile with -fPIC"),
7837                       reloc_property->name().c_str());
7838         this->issued_non_pic_error_ = true;
7839         return;
7840       }
7841
7842     case elfcpp::R_ARM_NONE:
7843       gold_unreachable();
7844     }
7845 }
7846
7847 // Scan a relocation for a local symbol.
7848 // FIXME: This only handles a subset of relocation types used by Android
7849 // on ARM v5te devices.
7850
7851 template<bool big_endian>
7852 inline void
7853 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7854                                     Layout* layout,
7855                                     Target_arm* target,
7856                                     Sized_relobj_file<32, big_endian>* object,
7857                                     unsigned int data_shndx,
7858                                     Output_section* output_section,
7859                                     const elfcpp::Rel<32, big_endian>& reloc,
7860                                     unsigned int r_type,
7861                                     const elfcpp::Sym<32, big_endian>& lsym,
7862                                     bool is_discarded)
7863 {
7864   if (is_discarded)
7865     return;
7866
7867   r_type = get_real_reloc_type(r_type);
7868   switch (r_type)
7869     {
7870     case elfcpp::R_ARM_NONE:
7871     case elfcpp::R_ARM_V4BX:
7872     case elfcpp::R_ARM_GNU_VTENTRY:
7873     case elfcpp::R_ARM_GNU_VTINHERIT:
7874       break;
7875
7876     case elfcpp::R_ARM_ABS32:
7877     case elfcpp::R_ARM_ABS32_NOI:
7878       // If building a shared library (or a position-independent
7879       // executable), we need to create a dynamic relocation for
7880       // this location. The relocation applied at link time will
7881       // apply the link-time value, so we flag the location with
7882       // an R_ARM_RELATIVE relocation so the dynamic loader can
7883       // relocate it easily.
7884       if (parameters->options().output_is_position_independent())
7885         {
7886           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7887           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7888           // If we are to add more other reloc types than R_ARM_ABS32,
7889           // we need to add check_non_pic(object, r_type) here.
7890           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7891                                       output_section, data_shndx,
7892                                       reloc.get_r_offset());
7893         }
7894       break;
7895
7896     case elfcpp::R_ARM_ABS16:
7897     case elfcpp::R_ARM_ABS12:
7898     case elfcpp::R_ARM_THM_ABS5:
7899     case elfcpp::R_ARM_ABS8:
7900     case elfcpp::R_ARM_BASE_ABS:
7901     case elfcpp::R_ARM_MOVW_ABS_NC:
7902     case elfcpp::R_ARM_MOVT_ABS:
7903     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7904     case elfcpp::R_ARM_THM_MOVT_ABS:
7905       // If building a shared library (or a position-independent
7906       // executable), we need to create a dynamic relocation for
7907       // this location. Because the addend needs to remain in the
7908       // data section, we need to be careful not to apply this
7909       // relocation statically.
7910       if (parameters->options().output_is_position_independent())
7911         {
7912           check_non_pic(object, r_type);
7913           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7914           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7915           if (lsym.get_st_type() != elfcpp::STT_SECTION)
7916             rel_dyn->add_local(object, r_sym, r_type, output_section,
7917                                data_shndx, reloc.get_r_offset());
7918           else
7919             {
7920               gold_assert(lsym.get_st_value() == 0);
7921               unsigned int shndx = lsym.get_st_shndx();
7922               bool is_ordinary;
7923               shndx = object->adjust_sym_shndx(r_sym, shndx,
7924                                                &is_ordinary);
7925               if (!is_ordinary)
7926                 object->error(_("section symbol %u has bad shndx %u"),
7927                               r_sym, shndx);
7928               else
7929                 rel_dyn->add_local_section(object, shndx,
7930                                            r_type, output_section,
7931                                            data_shndx, reloc.get_r_offset());
7932             }
7933         }
7934       break;
7935
7936     case elfcpp::R_ARM_REL32:
7937     case elfcpp::R_ARM_LDR_PC_G0:
7938     case elfcpp::R_ARM_SBREL32:
7939     case elfcpp::R_ARM_THM_CALL:
7940     case elfcpp::R_ARM_THM_PC8:
7941     case elfcpp::R_ARM_BASE_PREL:
7942     case elfcpp::R_ARM_PLT32:
7943     case elfcpp::R_ARM_CALL:
7944     case elfcpp::R_ARM_JUMP24:
7945     case elfcpp::R_ARM_THM_JUMP24:
7946     case elfcpp::R_ARM_SBREL31:
7947     case elfcpp::R_ARM_PREL31:
7948     case elfcpp::R_ARM_MOVW_PREL_NC:
7949     case elfcpp::R_ARM_MOVT_PREL:
7950     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7951     case elfcpp::R_ARM_THM_MOVT_PREL:
7952     case elfcpp::R_ARM_THM_JUMP19:
7953     case elfcpp::R_ARM_THM_JUMP6:
7954     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7955     case elfcpp::R_ARM_THM_PC12:
7956     case elfcpp::R_ARM_REL32_NOI:
7957     case elfcpp::R_ARM_ALU_PC_G0_NC:
7958     case elfcpp::R_ARM_ALU_PC_G0:
7959     case elfcpp::R_ARM_ALU_PC_G1_NC:
7960     case elfcpp::R_ARM_ALU_PC_G1:
7961     case elfcpp::R_ARM_ALU_PC_G2:
7962     case elfcpp::R_ARM_LDR_PC_G1:
7963     case elfcpp::R_ARM_LDR_PC_G2:
7964     case elfcpp::R_ARM_LDRS_PC_G0:
7965     case elfcpp::R_ARM_LDRS_PC_G1:
7966     case elfcpp::R_ARM_LDRS_PC_G2:
7967     case elfcpp::R_ARM_LDC_PC_G0:
7968     case elfcpp::R_ARM_LDC_PC_G1:
7969     case elfcpp::R_ARM_LDC_PC_G2:
7970     case elfcpp::R_ARM_ALU_SB_G0_NC:
7971     case elfcpp::R_ARM_ALU_SB_G0:
7972     case elfcpp::R_ARM_ALU_SB_G1_NC:
7973     case elfcpp::R_ARM_ALU_SB_G1:
7974     case elfcpp::R_ARM_ALU_SB_G2:
7975     case elfcpp::R_ARM_LDR_SB_G0:
7976     case elfcpp::R_ARM_LDR_SB_G1:
7977     case elfcpp::R_ARM_LDR_SB_G2:
7978     case elfcpp::R_ARM_LDRS_SB_G0:
7979     case elfcpp::R_ARM_LDRS_SB_G1:
7980     case elfcpp::R_ARM_LDRS_SB_G2:
7981     case elfcpp::R_ARM_LDC_SB_G0:
7982     case elfcpp::R_ARM_LDC_SB_G1:
7983     case elfcpp::R_ARM_LDC_SB_G2:
7984     case elfcpp::R_ARM_MOVW_BREL_NC:
7985     case elfcpp::R_ARM_MOVT_BREL:
7986     case elfcpp::R_ARM_MOVW_BREL:
7987     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7988     case elfcpp::R_ARM_THM_MOVT_BREL:
7989     case elfcpp::R_ARM_THM_MOVW_BREL:
7990     case elfcpp::R_ARM_THM_JUMP11:
7991     case elfcpp::R_ARM_THM_JUMP8:
7992       // We don't need to do anything for a relative addressing relocation
7993       // against a local symbol if it does not reference the GOT.
7994       break;
7995
7996     case elfcpp::R_ARM_GOTOFF32:
7997     case elfcpp::R_ARM_GOTOFF12:
7998       // We need a GOT section:
7999       target->got_section(symtab, layout);
8000       break;
8001
8002     case elfcpp::R_ARM_GOT_BREL:
8003     case elfcpp::R_ARM_GOT_PREL:
8004       {
8005         // The symbol requires a GOT entry.
8006         Arm_output_data_got<big_endian>* got =
8007           target->got_section(symtab, layout);
8008         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8009         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
8010           {
8011             // If we are generating a shared object, we need to add a
8012             // dynamic RELATIVE relocation for this symbol's GOT entry.
8013             if (parameters->options().output_is_position_independent())
8014               {
8015                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8016                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8017                 rel_dyn->add_local_relative(
8018                     object, r_sym, elfcpp::R_ARM_RELATIVE, got,
8019                     object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
8020               }
8021           }
8022       }
8023       break;
8024
8025     case elfcpp::R_ARM_TARGET1:
8026     case elfcpp::R_ARM_TARGET2:
8027       // This should have been mapped to another type already.
8028       // Fall through.
8029     case elfcpp::R_ARM_COPY:
8030     case elfcpp::R_ARM_GLOB_DAT:
8031     case elfcpp::R_ARM_JUMP_SLOT:
8032     case elfcpp::R_ARM_RELATIVE:
8033       // These are relocations which should only be seen by the
8034       // dynamic linker, and should never be seen here.
8035       gold_error(_("%s: unexpected reloc %u in object file"),
8036                  object->name().c_str(), r_type);
8037       break;
8038
8039
8040       // These are initial TLS relocs, which are expected when
8041       // linking.
8042     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8043     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8044     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8045     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8046     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8047       {
8048         bool output_is_shared = parameters->options().shared();
8049         const tls::Tls_optimization optimized_type
8050             = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
8051                                                          r_type);
8052         switch (r_type)
8053           {
8054           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8055             if (optimized_type == tls::TLSOPT_NONE)
8056               {
8057                 // Create a pair of GOT entries for the module index and
8058                 // dtv-relative offset.
8059                 Arm_output_data_got<big_endian>* got
8060                     = target->got_section(symtab, layout);
8061                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8062                 unsigned int shndx = lsym.get_st_shndx();
8063                 bool is_ordinary;
8064                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
8065                 if (!is_ordinary)
8066                   {
8067                     object->error(_("local symbol %u has bad shndx %u"),
8068                                   r_sym, shndx);
8069                     break;
8070                   }
8071
8072                 if (!parameters->doing_static_link())
8073                   got->add_local_pair_with_rel(object, r_sym, shndx,
8074                                                GOT_TYPE_TLS_PAIR,
8075                                                target->rel_dyn_section(layout),
8076                                                elfcpp::R_ARM_TLS_DTPMOD32);
8077                 else
8078                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
8079                                                       object, r_sym);
8080               }
8081             else
8082               // FIXME: TLS optimization not supported yet.
8083               gold_unreachable();
8084             break;
8085
8086           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
8087             if (optimized_type == tls::TLSOPT_NONE)
8088               {
8089                 // Create a GOT entry for the module index.
8090                 target->got_mod_index_entry(symtab, layout, object);
8091               }
8092             else
8093               // FIXME: TLS optimization not supported yet.
8094               gold_unreachable();
8095             break;
8096
8097           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
8098             break;
8099
8100           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
8101             layout->set_has_static_tls();
8102             if (optimized_type == tls::TLSOPT_NONE)
8103               {
8104                 // Create a GOT entry for the tp-relative offset.
8105                 Arm_output_data_got<big_endian>* got
8106                   = target->got_section(symtab, layout);
8107                 unsigned int r_sym =
8108                    elfcpp::elf_r_sym<32>(reloc.get_r_info());
8109                 if (!parameters->doing_static_link())
8110                     got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
8111                                             target->rel_dyn_section(layout),
8112                                             elfcpp::R_ARM_TLS_TPOFF32);
8113                 else if (!object->local_has_got_offset(r_sym,
8114                                                        GOT_TYPE_TLS_OFFSET))
8115                   {
8116                     got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
8117                     unsigned int got_offset =
8118                       object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
8119                     got->add_static_reloc(got_offset,
8120                                           elfcpp::R_ARM_TLS_TPOFF32, object,
8121                                           r_sym);
8122                   }
8123               }
8124             else
8125               // FIXME: TLS optimization not supported yet.
8126               gold_unreachable();
8127             break;
8128
8129           case elfcpp::R_ARM_TLS_LE32:          // Local-exec
8130             layout->set_has_static_tls();
8131             if (output_is_shared)
8132               {
8133                 // We need to create a dynamic relocation.
8134                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8135                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8136                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8137                 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8138                                    output_section, data_shndx,
8139                                    reloc.get_r_offset());
8140               }
8141             break;
8142
8143           default:
8144             gold_unreachable();
8145           }
8146       }
8147       break;
8148
8149     case elfcpp::R_ARM_PC24:
8150     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8151     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8152     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8153     default:
8154       unsupported_reloc_local(object, r_type);
8155       break;
8156     }
8157 }
8158
8159 // Report an unsupported relocation against a global symbol.
8160
8161 template<bool big_endian>
8162 void
8163 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8164     Sized_relobj_file<32, big_endian>* object,
8165     unsigned int r_type,
8166     Symbol* gsym)
8167 {
8168   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8169              object->name().c_str(), r_type, gsym->demangled_name().c_str());
8170 }
8171
8172 template<bool big_endian>
8173 inline bool
8174 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8175     unsigned int r_type)
8176 {
8177   switch (r_type)
8178     {
8179     case elfcpp::R_ARM_PC24:
8180     case elfcpp::R_ARM_THM_CALL:
8181     case elfcpp::R_ARM_PLT32:
8182     case elfcpp::R_ARM_CALL:
8183     case elfcpp::R_ARM_JUMP24:
8184     case elfcpp::R_ARM_THM_JUMP24:
8185     case elfcpp::R_ARM_SBREL31:
8186     case elfcpp::R_ARM_PREL31:
8187     case elfcpp::R_ARM_THM_JUMP19:
8188     case elfcpp::R_ARM_THM_JUMP6:
8189     case elfcpp::R_ARM_THM_JUMP11:
8190     case elfcpp::R_ARM_THM_JUMP8:
8191       // All the relocations above are branches except SBREL31 and PREL31.
8192       return false;
8193
8194     default:
8195       // Be conservative and assume this is a function pointer.
8196       return true;
8197     }
8198 }
8199
8200 template<bool big_endian>
8201 inline bool
8202 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8203   Symbol_table*,
8204   Layout*,
8205   Target_arm<big_endian>* target,
8206   Sized_relobj_file<32, big_endian>*,
8207   unsigned int,
8208   Output_section*,
8209   const elfcpp::Rel<32, big_endian>&,
8210   unsigned int r_type,
8211   const elfcpp::Sym<32, big_endian>&)
8212 {
8213   r_type = target->get_real_reloc_type(r_type);
8214   return possible_function_pointer_reloc(r_type);
8215 }
8216
8217 template<bool big_endian>
8218 inline bool
8219 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8220   Symbol_table*,
8221   Layout*,
8222   Target_arm<big_endian>* target,
8223   Sized_relobj_file<32, big_endian>*,
8224   unsigned int,
8225   Output_section*,
8226   const elfcpp::Rel<32, big_endian>&,
8227   unsigned int r_type,
8228   Symbol* gsym)
8229 {
8230   // GOT is not a function.
8231   if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8232     return false;
8233
8234   r_type = target->get_real_reloc_type(r_type);
8235   return possible_function_pointer_reloc(r_type);
8236 }
8237
8238 // Scan a relocation for a global symbol.
8239
8240 template<bool big_endian>
8241 inline void
8242 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8243                                      Layout* layout,
8244                                      Target_arm* target,
8245                                      Sized_relobj_file<32, big_endian>* object,
8246                                      unsigned int data_shndx,
8247                                      Output_section* output_section,
8248                                      const elfcpp::Rel<32, big_endian>& reloc,
8249                                      unsigned int r_type,
8250                                      Symbol* gsym)
8251 {
8252   // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8253   // section.  We check here to avoid creating a dynamic reloc against
8254   // _GLOBAL_OFFSET_TABLE_.
8255   if (!target->has_got_section()
8256       && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8257     target->got_section(symtab, layout);
8258
8259   r_type = get_real_reloc_type(r_type);
8260   switch (r_type)
8261     {
8262     case elfcpp::R_ARM_NONE:
8263     case elfcpp::R_ARM_V4BX:
8264     case elfcpp::R_ARM_GNU_VTENTRY:
8265     case elfcpp::R_ARM_GNU_VTINHERIT:
8266       break;
8267
8268     case elfcpp::R_ARM_ABS32:
8269     case elfcpp::R_ARM_ABS16:
8270     case elfcpp::R_ARM_ABS12:
8271     case elfcpp::R_ARM_THM_ABS5:
8272     case elfcpp::R_ARM_ABS8:
8273     case elfcpp::R_ARM_BASE_ABS:
8274     case elfcpp::R_ARM_MOVW_ABS_NC:
8275     case elfcpp::R_ARM_MOVT_ABS:
8276     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8277     case elfcpp::R_ARM_THM_MOVT_ABS:
8278     case elfcpp::R_ARM_ABS32_NOI:
8279       // Absolute addressing relocations.
8280       {
8281         // Make a PLT entry if necessary.
8282         if (this->symbol_needs_plt_entry(gsym))
8283           {
8284             target->make_plt_entry(symtab, layout, gsym);
8285             // Since this is not a PC-relative relocation, we may be
8286             // taking the address of a function. In that case we need to
8287             // set the entry in the dynamic symbol table to the address of
8288             // the PLT entry.
8289             if (gsym->is_from_dynobj() && !parameters->options().shared())
8290               gsym->set_needs_dynsym_value();
8291           }
8292         // Make a dynamic relocation if necessary.
8293         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8294           {
8295             if (gsym->may_need_copy_reloc())
8296               {
8297                 target->copy_reloc(symtab, layout, object,
8298                                    data_shndx, output_section, gsym, reloc);
8299               }
8300             else if ((r_type == elfcpp::R_ARM_ABS32
8301                       || r_type == elfcpp::R_ARM_ABS32_NOI)
8302                      && gsym->can_use_relative_reloc(false))
8303               {
8304                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8305                 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8306                                              output_section, object,
8307                                              data_shndx, reloc.get_r_offset());
8308               }
8309             else
8310               {
8311                 check_non_pic(object, r_type);
8312                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8313                 rel_dyn->add_global(gsym, r_type, output_section, object,
8314                                     data_shndx, reloc.get_r_offset());
8315               }
8316           }
8317       }
8318       break;
8319
8320     case elfcpp::R_ARM_GOTOFF32:
8321     case elfcpp::R_ARM_GOTOFF12:
8322       // We need a GOT section.
8323       target->got_section(symtab, layout);
8324       break;
8325
8326     case elfcpp::R_ARM_REL32:
8327     case elfcpp::R_ARM_LDR_PC_G0:
8328     case elfcpp::R_ARM_SBREL32:
8329     case elfcpp::R_ARM_THM_PC8:
8330     case elfcpp::R_ARM_BASE_PREL:
8331     case elfcpp::R_ARM_MOVW_PREL_NC:
8332     case elfcpp::R_ARM_MOVT_PREL:
8333     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8334     case elfcpp::R_ARM_THM_MOVT_PREL:
8335     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8336     case elfcpp::R_ARM_THM_PC12:
8337     case elfcpp::R_ARM_REL32_NOI:
8338     case elfcpp::R_ARM_ALU_PC_G0_NC:
8339     case elfcpp::R_ARM_ALU_PC_G0:
8340     case elfcpp::R_ARM_ALU_PC_G1_NC:
8341     case elfcpp::R_ARM_ALU_PC_G1:
8342     case elfcpp::R_ARM_ALU_PC_G2:
8343     case elfcpp::R_ARM_LDR_PC_G1:
8344     case elfcpp::R_ARM_LDR_PC_G2:
8345     case elfcpp::R_ARM_LDRS_PC_G0:
8346     case elfcpp::R_ARM_LDRS_PC_G1:
8347     case elfcpp::R_ARM_LDRS_PC_G2:
8348     case elfcpp::R_ARM_LDC_PC_G0:
8349     case elfcpp::R_ARM_LDC_PC_G1:
8350     case elfcpp::R_ARM_LDC_PC_G2:
8351     case elfcpp::R_ARM_ALU_SB_G0_NC:
8352     case elfcpp::R_ARM_ALU_SB_G0:
8353     case elfcpp::R_ARM_ALU_SB_G1_NC:
8354     case elfcpp::R_ARM_ALU_SB_G1:
8355     case elfcpp::R_ARM_ALU_SB_G2:
8356     case elfcpp::R_ARM_LDR_SB_G0:
8357     case elfcpp::R_ARM_LDR_SB_G1:
8358     case elfcpp::R_ARM_LDR_SB_G2:
8359     case elfcpp::R_ARM_LDRS_SB_G0:
8360     case elfcpp::R_ARM_LDRS_SB_G1:
8361     case elfcpp::R_ARM_LDRS_SB_G2:
8362     case elfcpp::R_ARM_LDC_SB_G0:
8363     case elfcpp::R_ARM_LDC_SB_G1:
8364     case elfcpp::R_ARM_LDC_SB_G2:
8365     case elfcpp::R_ARM_MOVW_BREL_NC:
8366     case elfcpp::R_ARM_MOVT_BREL:
8367     case elfcpp::R_ARM_MOVW_BREL:
8368     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8369     case elfcpp::R_ARM_THM_MOVT_BREL:
8370     case elfcpp::R_ARM_THM_MOVW_BREL:
8371       // Relative addressing relocations.
8372       {
8373         // Make a dynamic relocation if necessary.
8374         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8375           {
8376             if (target->may_need_copy_reloc(gsym))
8377               {
8378                 target->copy_reloc(symtab, layout, object,
8379                                    data_shndx, output_section, gsym, reloc);
8380               }
8381             else
8382               {
8383                 check_non_pic(object, r_type);
8384                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8385                 rel_dyn->add_global(gsym, r_type, output_section, object,
8386                                     data_shndx, reloc.get_r_offset());
8387               }
8388           }
8389       }
8390       break;
8391
8392     case elfcpp::R_ARM_THM_CALL:
8393     case elfcpp::R_ARM_PLT32:
8394     case elfcpp::R_ARM_CALL:
8395     case elfcpp::R_ARM_JUMP24:
8396     case elfcpp::R_ARM_THM_JUMP24:
8397     case elfcpp::R_ARM_SBREL31:
8398     case elfcpp::R_ARM_PREL31:
8399     case elfcpp::R_ARM_THM_JUMP19:
8400     case elfcpp::R_ARM_THM_JUMP6:
8401     case elfcpp::R_ARM_THM_JUMP11:
8402     case elfcpp::R_ARM_THM_JUMP8:
8403       // All the relocation above are branches except for the PREL31 ones.
8404       // A PREL31 relocation can point to a personality function in a shared
8405       // library.  In that case we want to use a PLT because we want to
8406       // call the personality routine and the dynamic linkers we care about
8407       // do not support dynamic PREL31 relocations. An REL31 relocation may
8408       // point to a function whose unwinding behaviour is being described but
8409       // we will not mistakenly generate a PLT for that because we should use
8410       // a local section symbol.
8411
8412       // If the symbol is fully resolved, this is just a relative
8413       // local reloc.  Otherwise we need a PLT entry.
8414       if (gsym->final_value_is_known())
8415         break;
8416       // If building a shared library, we can also skip the PLT entry
8417       // if the symbol is defined in the output file and is protected
8418       // or hidden.
8419       if (gsym->is_defined()
8420           && !gsym->is_from_dynobj()
8421           && !gsym->is_preemptible())
8422         break;
8423       target->make_plt_entry(symtab, layout, gsym);
8424       break;
8425
8426     case elfcpp::R_ARM_GOT_BREL:
8427     case elfcpp::R_ARM_GOT_ABS:
8428     case elfcpp::R_ARM_GOT_PREL:
8429       {
8430         // The symbol requires a GOT entry.
8431         Arm_output_data_got<big_endian>* got =
8432           target->got_section(symtab, layout);
8433         if (gsym->final_value_is_known())
8434           got->add_global(gsym, GOT_TYPE_STANDARD);
8435         else
8436           {
8437             // If this symbol is not fully resolved, we need to add a
8438             // GOT entry with a dynamic relocation.
8439             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8440             if (gsym->is_from_dynobj()
8441                 || gsym->is_undefined()
8442                 || gsym->is_preemptible()
8443                 || (gsym->visibility() == elfcpp::STV_PROTECTED
8444                     && parameters->options().shared()))
8445               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8446                                        rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8447             else
8448               {
8449                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
8450                   rel_dyn->add_global_relative(
8451                       gsym, elfcpp::R_ARM_RELATIVE, got,
8452                       gsym->got_offset(GOT_TYPE_STANDARD));
8453               }
8454           }
8455       }
8456       break;
8457
8458     case elfcpp::R_ARM_TARGET1:
8459     case elfcpp::R_ARM_TARGET2:
8460       // These should have been mapped to other types already.
8461       // Fall through.
8462     case elfcpp::R_ARM_COPY:
8463     case elfcpp::R_ARM_GLOB_DAT:
8464     case elfcpp::R_ARM_JUMP_SLOT:
8465     case elfcpp::R_ARM_RELATIVE:
8466       // These are relocations which should only be seen by the
8467       // dynamic linker, and should never be seen here.
8468       gold_error(_("%s: unexpected reloc %u in object file"),
8469                  object->name().c_str(), r_type);
8470       break;
8471
8472       // These are initial tls relocs, which are expected when
8473       // linking.
8474     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8475     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8476     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8477     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8478     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8479       {
8480         const bool is_final = gsym->final_value_is_known();
8481         const tls::Tls_optimization optimized_type
8482             = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8483         switch (r_type)
8484           {
8485           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8486             if (optimized_type == tls::TLSOPT_NONE)
8487               {
8488                 // Create a pair of GOT entries for the module index and
8489                 // dtv-relative offset.
8490                 Arm_output_data_got<big_endian>* got
8491                     = target->got_section(symtab, layout);
8492                 if (!parameters->doing_static_link())
8493                   got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8494                                                 target->rel_dyn_section(layout),
8495                                                 elfcpp::R_ARM_TLS_DTPMOD32,
8496                                                 elfcpp::R_ARM_TLS_DTPOFF32);
8497                 else
8498                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8499               }
8500             else
8501               // FIXME: TLS optimization not supported yet.
8502               gold_unreachable();
8503             break;
8504
8505           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
8506             if (optimized_type == tls::TLSOPT_NONE)
8507               {
8508                 // Create a GOT entry for the module index.
8509                 target->got_mod_index_entry(symtab, layout, object);
8510               }
8511             else
8512               // FIXME: TLS optimization not supported yet.
8513               gold_unreachable();
8514             break;
8515
8516           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
8517             break;
8518
8519           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
8520             layout->set_has_static_tls();
8521             if (optimized_type == tls::TLSOPT_NONE)
8522               {
8523                 // Create a GOT entry for the tp-relative offset.
8524                 Arm_output_data_got<big_endian>* got
8525                   = target->got_section(symtab, layout);
8526                 if (!parameters->doing_static_link())
8527                   got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
8528                                            target->rel_dyn_section(layout),
8529                                            elfcpp::R_ARM_TLS_TPOFF32);
8530                 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
8531                   {
8532                     got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
8533                     unsigned int got_offset =
8534                        gsym->got_offset(GOT_TYPE_TLS_OFFSET);
8535                     got->add_static_reloc(got_offset,
8536                                           elfcpp::R_ARM_TLS_TPOFF32, gsym);
8537                   }
8538               }
8539             else
8540               // FIXME: TLS optimization not supported yet.
8541               gold_unreachable();
8542             break;
8543
8544           case elfcpp::R_ARM_TLS_LE32:  // Local-exec
8545             layout->set_has_static_tls();
8546             if (parameters->options().shared())
8547               {
8548                 // We need to create a dynamic relocation.
8549                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8550                 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
8551                                     output_section, object,
8552                                     data_shndx, reloc.get_r_offset());
8553               }
8554             break;
8555
8556           default:
8557             gold_unreachable();
8558           }
8559       }
8560       break;
8561
8562     case elfcpp::R_ARM_PC24:
8563     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8564     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8565     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8566     default:
8567       unsupported_reloc_global(object, r_type, gsym);
8568       break;
8569     }
8570 }
8571
8572 // Process relocations for gc.
8573
8574 template<bool big_endian>
8575 void
8576 Target_arm<big_endian>::gc_process_relocs(
8577     Symbol_table* symtab,
8578     Layout* layout,
8579     Sized_relobj_file<32, big_endian>* object,
8580     unsigned int data_shndx,
8581     unsigned int,
8582     const unsigned char* prelocs,
8583     size_t reloc_count,
8584     Output_section* output_section,
8585     bool needs_special_offset_handling,
8586     size_t local_symbol_count,
8587     const unsigned char* plocal_symbols)
8588 {
8589   typedef Target_arm<big_endian> Arm;
8590   typedef typename Target_arm<big_endian>::Scan Scan;
8591
8592   gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
8593                           typename Target_arm::Relocatable_size_for_reloc>(
8594     symtab,
8595     layout,
8596     this,
8597     object,
8598     data_shndx,
8599     prelocs,
8600     reloc_count,
8601     output_section,
8602     needs_special_offset_handling,
8603     local_symbol_count,
8604     plocal_symbols);
8605 }
8606
8607 // Scan relocations for a section.
8608
8609 template<bool big_endian>
8610 void
8611 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
8612                                     Layout* layout,
8613                                     Sized_relobj_file<32, big_endian>* object,
8614                                     unsigned int data_shndx,
8615                                     unsigned int sh_type,
8616                                     const unsigned char* prelocs,
8617                                     size_t reloc_count,
8618                                     Output_section* output_section,
8619                                     bool needs_special_offset_handling,
8620                                     size_t local_symbol_count,
8621                                     const unsigned char* plocal_symbols)
8622 {
8623   typedef typename Target_arm<big_endian>::Scan Scan;
8624   if (sh_type == elfcpp::SHT_RELA)
8625     {
8626       gold_error(_("%s: unsupported RELA reloc section"),
8627                  object->name().c_str());
8628       return;
8629     }
8630
8631   gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
8632     symtab,
8633     layout,
8634     this,
8635     object,
8636     data_shndx,
8637     prelocs,
8638     reloc_count,
8639     output_section,
8640     needs_special_offset_handling,
8641     local_symbol_count,
8642     plocal_symbols);
8643 }
8644
8645 // Finalize the sections.
8646
8647 template<bool big_endian>
8648 void
8649 Target_arm<big_endian>::do_finalize_sections(
8650     Layout* layout,
8651     const Input_objects* input_objects,
8652     Symbol_table*)
8653 {
8654   bool merged_any_attributes = false;
8655   // Merge processor-specific flags.
8656   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
8657        p != input_objects->relobj_end();
8658        ++p)
8659     {
8660       Arm_relobj<big_endian>* arm_relobj =
8661         Arm_relobj<big_endian>::as_arm_relobj(*p);
8662       if (arm_relobj->merge_flags_and_attributes())
8663         {
8664           this->merge_processor_specific_flags(
8665               arm_relobj->name(),
8666               arm_relobj->processor_specific_flags());
8667           this->merge_object_attributes(arm_relobj->name().c_str(),
8668                                         arm_relobj->attributes_section_data());
8669           merged_any_attributes = true;
8670         }
8671     }
8672
8673   for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
8674        p != input_objects->dynobj_end();
8675        ++p)
8676     {
8677       Arm_dynobj<big_endian>* arm_dynobj =
8678         Arm_dynobj<big_endian>::as_arm_dynobj(*p);
8679       this->merge_processor_specific_flags(
8680           arm_dynobj->name(),
8681           arm_dynobj->processor_specific_flags());
8682       this->merge_object_attributes(arm_dynobj->name().c_str(),
8683                                     arm_dynobj->attributes_section_data());
8684       merged_any_attributes = true;
8685     }
8686
8687   // Create an empty uninitialized attribute section if we still don't have it
8688   // at this moment.  This happens if there is no attributes sections in all
8689   // inputs.
8690   if (this->attributes_section_data_ == NULL)
8691     this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
8692
8693   const Object_attribute* cpu_arch_attr =
8694     this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
8695   // Check if we need to use Cortex-A8 workaround.
8696   if (parameters->options().user_set_fix_cortex_a8())
8697     this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
8698   else
8699     {
8700       // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
8701       // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
8702       // profile.
8703       const Object_attribute* cpu_arch_profile_attr =
8704         this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
8705       this->fix_cortex_a8_ =
8706         (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
8707          && (cpu_arch_profile_attr->int_value() == 'A'
8708              || cpu_arch_profile_attr->int_value() == 0));
8709     }
8710
8711   // Check if we can use V4BX interworking.
8712   // The V4BX interworking stub contains BX instruction,
8713   // which is not specified for some profiles.
8714   if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
8715       && !this->may_use_v4t_interworking())
8716     gold_error(_("unable to provide V4BX reloc interworking fix up; "
8717                  "the target profile does not support BX instruction"));
8718
8719   // Fill in some more dynamic tags.
8720   const Reloc_section* rel_plt = (this->plt_ == NULL
8721                                   ? NULL
8722                                   : this->plt_->rel_plt());
8723   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
8724                                   this->rel_dyn_, true, false);
8725
8726   // Emit any relocs we saved in an attempt to avoid generating COPY
8727   // relocs.
8728   if (this->copy_relocs_.any_saved_relocs())
8729     this->copy_relocs_.emit(this->rel_dyn_section(layout));
8730
8731   // Handle the .ARM.exidx section.
8732   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8733
8734   if (!parameters->options().relocatable())
8735     {
8736       if (exidx_section != NULL
8737           && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
8738         {
8739           // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8740           // the .ARM.exidx section.
8741           if (!layout->script_options()->saw_phdrs_clause())
8742             {
8743               gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
8744                                                       0)
8745                           == NULL);
8746               Output_segment*  exidx_segment =
8747                 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8748               exidx_segment->add_output_section_to_nonload(exidx_section,
8749                                                            elfcpp::PF_R);
8750             }
8751         }
8752     }
8753
8754   // Create an .ARM.attributes section if we have merged any attributes
8755   // from inputs.
8756   if (merged_any_attributes)
8757     {
8758       Output_attributes_section_data* attributes_section =
8759       new Output_attributes_section_data(*this->attributes_section_data_);
8760       layout->add_output_section_data(".ARM.attributes",
8761                                       elfcpp::SHT_ARM_ATTRIBUTES, 0,
8762                                       attributes_section, ORDER_INVALID,
8763                                       false);
8764     }
8765
8766   // Fix up links in section EXIDX headers.
8767   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
8768        p != layout->section_list().end();
8769        ++p)
8770     if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
8771       {
8772         Arm_output_section<big_endian>* os =
8773           Arm_output_section<big_endian>::as_arm_output_section(*p);
8774         os->set_exidx_section_link();
8775       }
8776 }
8777
8778 // Return whether a direct absolute static relocation needs to be applied.
8779 // In cases where Scan::local() or Scan::global() has created
8780 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8781 // of the relocation is carried in the data, and we must not
8782 // apply the static relocation.
8783
8784 template<bool big_endian>
8785 inline bool
8786 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8787     const Sized_symbol<32>* gsym,
8788     unsigned int r_type,
8789     bool is_32bit,
8790     Output_section* output_section)
8791 {
8792   // If the output section is not allocated, then we didn't call
8793   // scan_relocs, we didn't create a dynamic reloc, and we must apply
8794   // the reloc here.
8795   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8796       return true;
8797
8798   int ref_flags = Scan::get_reference_flags(r_type);
8799
8800   // For local symbols, we will have created a non-RELATIVE dynamic
8801   // relocation only if (a) the output is position independent,
8802   // (b) the relocation is absolute (not pc- or segment-relative), and
8803   // (c) the relocation is not 32 bits wide.
8804   if (gsym == NULL)
8805     return !(parameters->options().output_is_position_independent()
8806              && (ref_flags & Symbol::ABSOLUTE_REF)
8807              && !is_32bit);
8808
8809   // For global symbols, we use the same helper routines used in the
8810   // scan pass.  If we did not create a dynamic relocation, or if we
8811   // created a RELATIVE dynamic relocation, we should apply the static
8812   // relocation.
8813   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8814   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8815                  && gsym->can_use_relative_reloc(ref_flags
8816                                                  & Symbol::FUNCTION_CALL);
8817   return !has_dyn || is_rel;
8818 }
8819
8820 // Perform a relocation.
8821
8822 template<bool big_endian>
8823 inline bool
8824 Target_arm<big_endian>::Relocate::relocate(
8825     const Relocate_info<32, big_endian>* relinfo,
8826     Target_arm* target,
8827     Output_section* output_section,
8828     size_t relnum,
8829     const elfcpp::Rel<32, big_endian>& rel,
8830     unsigned int r_type,
8831     const Sized_symbol<32>* gsym,
8832     const Symbol_value<32>* psymval,
8833     unsigned char* view,
8834     Arm_address address,
8835     section_size_type view_size)
8836 {
8837   typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8838
8839   r_type = get_real_reloc_type(r_type);
8840   const Arm_reloc_property* reloc_property =
8841     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8842   if (reloc_property == NULL)
8843     {
8844       std::string reloc_name =
8845         arm_reloc_property_table->reloc_name_in_error_message(r_type);
8846       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8847                              _("cannot relocate %s in object file"),
8848                              reloc_name.c_str());
8849       return true;
8850     }
8851
8852   const Arm_relobj<big_endian>* object =
8853     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8854
8855   // If the final branch target of a relocation is THUMB instruction, this
8856   // is 1.  Otherwise it is 0.
8857   Arm_address thumb_bit = 0;
8858   Symbol_value<32> symval;
8859   bool is_weakly_undefined_without_plt = false;
8860   bool have_got_offset = false;
8861   unsigned int got_offset = 0;
8862
8863   // If the relocation uses the GOT entry of a symbol instead of the symbol
8864   // itself, we don't care about whether the symbol is defined or what kind
8865   // of symbol it is.
8866   if (reloc_property->uses_got_entry())
8867     {
8868       // Get the GOT offset.
8869       // The GOT pointer points to the end of the GOT section.
8870       // We need to subtract the size of the GOT section to get
8871       // the actual offset to use in the relocation.
8872       // TODO: We should move GOT offset computing code in TLS relocations
8873       // to here.
8874       switch (r_type)
8875         {
8876         case elfcpp::R_ARM_GOT_BREL:
8877         case elfcpp::R_ARM_GOT_PREL:
8878           if (gsym != NULL)
8879             {
8880               gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8881               got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8882                             - target->got_size());
8883             }
8884           else
8885             {
8886               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8887               gold_assert(object->local_has_got_offset(r_sym,
8888                                                        GOT_TYPE_STANDARD));
8889               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8890                             - target->got_size());
8891             }
8892           have_got_offset = true;
8893           break;
8894
8895         default:
8896           break;
8897         }
8898     }
8899   else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8900     {
8901       if (gsym != NULL)
8902         {
8903           // This is a global symbol.  Determine if we use PLT and if the
8904           // final target is THUMB.
8905           if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
8906             {
8907               // This uses a PLT, change the symbol value.
8908               symval.set_output_value(target->plt_section()->address()
8909                                       + gsym->plt_offset());
8910               psymval = &symval;
8911             }
8912           else if (gsym->is_weak_undefined())
8913             {
8914               // This is a weakly undefined symbol and we do not use PLT
8915               // for this relocation.  A branch targeting this symbol will
8916               // be converted into an NOP.
8917               is_weakly_undefined_without_plt = true;
8918             }
8919           else if (gsym->is_undefined() && reloc_property->uses_symbol())
8920             {
8921               // This relocation uses the symbol value but the symbol is
8922               // undefined.  Exit early and have the caller reporting an
8923               // error.
8924               return true;
8925             }
8926           else
8927             {
8928               // Set thumb bit if symbol:
8929               // -Has type STT_ARM_TFUNC or
8930               // -Has type STT_FUNC, is defined and with LSB in value set.
8931               thumb_bit =
8932                 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8933                  || (gsym->type() == elfcpp::STT_FUNC
8934                      && !gsym->is_undefined()
8935                      && ((psymval->value(object, 0) & 1) != 0)))
8936                 ? 1
8937                 : 0);
8938             }
8939         }
8940       else
8941         {
8942           // This is a local symbol.  Determine if the final target is THUMB.
8943           // We saved this information when all the local symbols were read.
8944           elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8945           unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8946           thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8947         }
8948     }
8949   else
8950     {
8951       // This is a fake relocation synthesized for a stub.  It does not have
8952       // a real symbol.  We just look at the LSB of the symbol value to
8953       // determine if the target is THUMB or not.
8954       thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8955     }
8956
8957   // Strip LSB if this points to a THUMB target.
8958   if (thumb_bit != 0
8959       && reloc_property->uses_thumb_bit()
8960       && ((psymval->value(object, 0) & 1) != 0))
8961     {
8962       Arm_address stripped_value =
8963         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8964       symval.set_output_value(stripped_value);
8965       psymval = &symval;
8966     }
8967
8968   // To look up relocation stubs, we need to pass the symbol table index of
8969   // a local symbol.
8970   unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8971
8972   // Get the addressing origin of the output segment defining the
8973   // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8974   Arm_address sym_origin = 0;
8975   if (reloc_property->uses_symbol_base())
8976     {
8977       if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8978         // R_ARM_BASE_ABS with the NULL symbol will give the
8979         // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8980         // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8981         sym_origin = target->got_plt_section()->address();
8982       else if (gsym == NULL)
8983         sym_origin = 0;
8984       else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8985         sym_origin = gsym->output_segment()->vaddr();
8986       else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
8987         sym_origin = gsym->output_data()->address();
8988
8989       // TODO: Assumes the segment base to be zero for the global symbols
8990       // till the proper support for the segment-base-relative addressing
8991       // will be implemented.  This is consistent with GNU ld.
8992     }
8993
8994   // For relative addressing relocation, find out the relative address base.
8995   Arm_address relative_address_base = 0;
8996   switch(reloc_property->relative_address_base())
8997     {
8998     case Arm_reloc_property::RAB_NONE:
8999     // Relocations with relative address bases RAB_TLS and RAB_tp are
9000     // handled by relocate_tls.  So we do not need to do anything here.
9001     case Arm_reloc_property::RAB_TLS:
9002     case Arm_reloc_property::RAB_tp:
9003       break;
9004     case Arm_reloc_property::RAB_B_S:
9005       relative_address_base = sym_origin;
9006       break;
9007     case Arm_reloc_property::RAB_GOT_ORG:
9008       relative_address_base = target->got_plt_section()->address();
9009       break;
9010     case Arm_reloc_property::RAB_P:
9011       relative_address_base = address;
9012       break;
9013     case Arm_reloc_property::RAB_Pa:
9014       relative_address_base = address & 0xfffffffcU;
9015       break;
9016     default:
9017       gold_unreachable();
9018     }
9019
9020   typename Arm_relocate_functions::Status reloc_status =
9021         Arm_relocate_functions::STATUS_OKAY;
9022   bool check_overflow = reloc_property->checks_overflow();
9023   switch (r_type)
9024     {
9025     case elfcpp::R_ARM_NONE:
9026       break;
9027
9028     case elfcpp::R_ARM_ABS8:
9029       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9030         reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
9031       break;
9032
9033     case elfcpp::R_ARM_ABS12:
9034       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9035         reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
9036       break;
9037
9038     case elfcpp::R_ARM_ABS16:
9039       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9040         reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
9041       break;
9042
9043     case elfcpp::R_ARM_ABS32:
9044       if (should_apply_static_reloc(gsym, r_type, true, output_section))
9045         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9046                                                      thumb_bit);
9047       break;
9048
9049     case elfcpp::R_ARM_ABS32_NOI:
9050       if (should_apply_static_reloc(gsym, r_type, true, output_section))
9051         // No thumb bit for this relocation: (S + A)
9052         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9053                                                      0);
9054       break;
9055
9056     case elfcpp::R_ARM_MOVW_ABS_NC:
9057       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9058         reloc_status = Arm_relocate_functions::movw(view, object, psymval,
9059                                                     0, thumb_bit,
9060                                                     check_overflow);
9061       break;
9062
9063     case elfcpp::R_ARM_MOVT_ABS:
9064       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9065         reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
9066       break;
9067
9068     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9069       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9070         reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
9071                                                         0, thumb_bit, false);
9072       break;
9073
9074     case elfcpp::R_ARM_THM_MOVT_ABS:
9075       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9076         reloc_status = Arm_relocate_functions::thm_movt(view, object,
9077                                                         psymval, 0);
9078       break;
9079
9080     case elfcpp::R_ARM_MOVW_PREL_NC:
9081     case elfcpp::R_ARM_MOVW_BREL_NC:
9082     case elfcpp::R_ARM_MOVW_BREL:
9083       reloc_status =
9084         Arm_relocate_functions::movw(view, object, psymval,
9085                                      relative_address_base, thumb_bit,
9086                                      check_overflow);
9087       break;
9088
9089     case elfcpp::R_ARM_MOVT_PREL:
9090     case elfcpp::R_ARM_MOVT_BREL:
9091       reloc_status =
9092         Arm_relocate_functions::movt(view, object, psymval,
9093                                      relative_address_base);
9094       break;
9095
9096     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9097     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9098     case elfcpp::R_ARM_THM_MOVW_BREL:
9099       reloc_status =
9100         Arm_relocate_functions::thm_movw(view, object, psymval,
9101                                          relative_address_base,
9102                                          thumb_bit, check_overflow);
9103       break;
9104
9105     case elfcpp::R_ARM_THM_MOVT_PREL:
9106     case elfcpp::R_ARM_THM_MOVT_BREL:
9107       reloc_status =
9108         Arm_relocate_functions::thm_movt(view, object, psymval,
9109                                          relative_address_base);
9110       break;
9111
9112     case elfcpp::R_ARM_REL32:
9113       reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9114                                                    address, thumb_bit);
9115       break;
9116
9117     case elfcpp::R_ARM_THM_ABS5:
9118       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9119         reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
9120       break;
9121
9122     // Thumb long branches.
9123     case elfcpp::R_ARM_THM_CALL:
9124     case elfcpp::R_ARM_THM_XPC22:
9125     case elfcpp::R_ARM_THM_JUMP24:
9126       reloc_status =
9127         Arm_relocate_functions::thumb_branch_common(
9128             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9129             thumb_bit, is_weakly_undefined_without_plt);
9130       break;
9131
9132     case elfcpp::R_ARM_GOTOFF32:
9133       {
9134         Arm_address got_origin;
9135         got_origin = target->got_plt_section()->address();
9136         reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9137                                                      got_origin, thumb_bit);
9138       }
9139       break;
9140
9141     case elfcpp::R_ARM_BASE_PREL:
9142       gold_assert(gsym != NULL);
9143       reloc_status =
9144           Arm_relocate_functions::base_prel(view, sym_origin, address);
9145       break;
9146
9147     case elfcpp::R_ARM_BASE_ABS:
9148       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9149         reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
9150       break;
9151
9152     case elfcpp::R_ARM_GOT_BREL:
9153       gold_assert(have_got_offset);
9154       reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
9155       break;
9156
9157     case elfcpp::R_ARM_GOT_PREL:
9158       gold_assert(have_got_offset);
9159       // Get the address origin for GOT PLT, which is allocated right
9160       // after the GOT section, to calculate an absolute address of
9161       // the symbol GOT entry (got_origin + got_offset).
9162       Arm_address got_origin;
9163       got_origin = target->got_plt_section()->address();
9164       reloc_status = Arm_relocate_functions::got_prel(view,
9165                                                       got_origin + got_offset,
9166                                                       address);
9167       break;
9168
9169     case elfcpp::R_ARM_PLT32:
9170     case elfcpp::R_ARM_CALL:
9171     case elfcpp::R_ARM_JUMP24:
9172     case elfcpp::R_ARM_XPC25:
9173       gold_assert(gsym == NULL
9174                   || gsym->has_plt_offset()
9175                   || gsym->final_value_is_known()
9176                   || (gsym->is_defined()
9177                       && !gsym->is_from_dynobj()
9178                       && !gsym->is_preemptible()));
9179       reloc_status =
9180         Arm_relocate_functions::arm_branch_common(
9181             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9182             thumb_bit, is_weakly_undefined_without_plt);
9183       break;
9184
9185     case elfcpp::R_ARM_THM_JUMP19:
9186       reloc_status =
9187         Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9188                                            thumb_bit);
9189       break;
9190
9191     case elfcpp::R_ARM_THM_JUMP6:
9192       reloc_status =
9193         Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9194       break;
9195
9196     case elfcpp::R_ARM_THM_JUMP8:
9197       reloc_status =
9198         Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9199       break;
9200
9201     case elfcpp::R_ARM_THM_JUMP11:
9202       reloc_status =
9203         Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9204       break;
9205
9206     case elfcpp::R_ARM_PREL31:
9207       reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9208                                                     address, thumb_bit);
9209       break;
9210
9211     case elfcpp::R_ARM_V4BX:
9212       if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9213         {
9214           const bool is_v4bx_interworking =
9215               (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9216           reloc_status =
9217             Arm_relocate_functions::v4bx(relinfo, view, object, address,
9218                                          is_v4bx_interworking);
9219         }
9220       break;
9221
9222     case elfcpp::R_ARM_THM_PC8:
9223       reloc_status =
9224         Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9225       break;
9226
9227     case elfcpp::R_ARM_THM_PC12:
9228       reloc_status =
9229         Arm_relocate_functions::thm_pc12(view, object, psymval, address);
9230       break;
9231
9232     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9233       reloc_status =
9234         Arm_relocate_functions::thm_alu11(view, object, psymval, address,
9235                                           thumb_bit);
9236       break;
9237
9238     case elfcpp::R_ARM_ALU_PC_G0_NC:
9239     case elfcpp::R_ARM_ALU_PC_G0:
9240     case elfcpp::R_ARM_ALU_PC_G1_NC:
9241     case elfcpp::R_ARM_ALU_PC_G1:
9242     case elfcpp::R_ARM_ALU_PC_G2:
9243     case elfcpp::R_ARM_ALU_SB_G0_NC:
9244     case elfcpp::R_ARM_ALU_SB_G0:
9245     case elfcpp::R_ARM_ALU_SB_G1_NC:
9246     case elfcpp::R_ARM_ALU_SB_G1:
9247     case elfcpp::R_ARM_ALU_SB_G2:
9248       reloc_status =
9249         Arm_relocate_functions::arm_grp_alu(view, object, psymval,
9250                                             reloc_property->group_index(),
9251                                             relative_address_base,
9252                                             thumb_bit, check_overflow);
9253       break;
9254
9255     case elfcpp::R_ARM_LDR_PC_G0:
9256     case elfcpp::R_ARM_LDR_PC_G1:
9257     case elfcpp::R_ARM_LDR_PC_G2:
9258     case elfcpp::R_ARM_LDR_SB_G0:
9259     case elfcpp::R_ARM_LDR_SB_G1:
9260     case elfcpp::R_ARM_LDR_SB_G2:
9261       reloc_status =
9262           Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9263                                               reloc_property->group_index(),
9264                                               relative_address_base);
9265       break;
9266
9267     case elfcpp::R_ARM_LDRS_PC_G0:
9268     case elfcpp::R_ARM_LDRS_PC_G1:
9269     case elfcpp::R_ARM_LDRS_PC_G2:
9270     case elfcpp::R_ARM_LDRS_SB_G0:
9271     case elfcpp::R_ARM_LDRS_SB_G1:
9272     case elfcpp::R_ARM_LDRS_SB_G2:
9273       reloc_status =
9274           Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9275                                                reloc_property->group_index(),
9276                                                relative_address_base);
9277       break;
9278
9279     case elfcpp::R_ARM_LDC_PC_G0:
9280     case elfcpp::R_ARM_LDC_PC_G1:
9281     case elfcpp::R_ARM_LDC_PC_G2:
9282     case elfcpp::R_ARM_LDC_SB_G0:
9283     case elfcpp::R_ARM_LDC_SB_G1:
9284     case elfcpp::R_ARM_LDC_SB_G2:
9285       reloc_status =
9286           Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9287                                               reloc_property->group_index(),
9288                                               relative_address_base);
9289       break;
9290
9291       // These are initial tls relocs, which are expected when
9292       // linking.
9293     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9294     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9295     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9296     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9297     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9298       reloc_status =
9299         this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9300                            view, address, view_size);
9301       break;
9302
9303     // The known and unknown unsupported and/or deprecated relocations.
9304     case elfcpp::R_ARM_PC24:
9305     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9306     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9307     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9308     default:
9309       // Just silently leave the method. We should get an appropriate error
9310       // message in the scan methods.
9311       break;
9312     }
9313
9314   // Report any errors.
9315   switch (reloc_status)
9316     {
9317     case Arm_relocate_functions::STATUS_OKAY:
9318       break;
9319     case Arm_relocate_functions::STATUS_OVERFLOW:
9320       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9321                              _("relocation overflow in %s"),
9322                              reloc_property->name().c_str());
9323       break;
9324     case Arm_relocate_functions::STATUS_BAD_RELOC:
9325       gold_error_at_location(
9326         relinfo,
9327         relnum,
9328         rel.get_r_offset(),
9329         _("unexpected opcode while processing relocation %s"),
9330         reloc_property->name().c_str());
9331       break;
9332     default:
9333       gold_unreachable();
9334     }
9335
9336   return true;
9337 }
9338
9339 // Perform a TLS relocation.
9340
9341 template<bool big_endian>
9342 inline typename Arm_relocate_functions<big_endian>::Status
9343 Target_arm<big_endian>::Relocate::relocate_tls(
9344     const Relocate_info<32, big_endian>* relinfo,
9345     Target_arm<big_endian>* target,
9346     size_t relnum,
9347     const elfcpp::Rel<32, big_endian>& rel,
9348     unsigned int r_type,
9349     const Sized_symbol<32>* gsym,
9350     const Symbol_value<32>* psymval,
9351     unsigned char* view,
9352     elfcpp::Elf_types<32>::Elf_Addr address,
9353     section_size_type /*view_size*/ )
9354 {
9355   typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9356   typedef Relocate_functions<32, big_endian> RelocFuncs;
9357   Output_segment* tls_segment = relinfo->layout->tls_segment();
9358
9359   const Sized_relobj_file<32, big_endian>* object = relinfo->object;
9360
9361   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9362
9363   const bool is_final = (gsym == NULL
9364                          ? !parameters->options().shared()
9365                          : gsym->final_value_is_known());
9366   const tls::Tls_optimization optimized_type
9367       = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9368   switch (r_type)
9369     {
9370     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9371         {
9372           unsigned int got_type = GOT_TYPE_TLS_PAIR;
9373           unsigned int got_offset;
9374           if (gsym != NULL)
9375             {
9376               gold_assert(gsym->has_got_offset(got_type));
9377               got_offset = gsym->got_offset(got_type) - target->got_size();
9378             }
9379           else
9380             {
9381               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9382               gold_assert(object->local_has_got_offset(r_sym, got_type));
9383               got_offset = (object->local_got_offset(r_sym, got_type)
9384                             - target->got_size());
9385             }
9386           if (optimized_type == tls::TLSOPT_NONE)
9387             {
9388               Arm_address got_entry =
9389                 target->got_plt_section()->address() + got_offset;
9390
9391               // Relocate the field with the PC relative offset of the pair of
9392               // GOT entries.
9393               RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9394               return ArmRelocFuncs::STATUS_OKAY;
9395             }
9396         }
9397       break;
9398
9399     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9400       if (optimized_type == tls::TLSOPT_NONE)
9401         {
9402           // Relocate the field with the offset of the GOT entry for
9403           // the module index.
9404           unsigned int got_offset;
9405           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9406                         - target->got_size());
9407           Arm_address got_entry =
9408             target->got_plt_section()->address() + got_offset;
9409
9410           // Relocate the field with the PC relative offset of the pair of
9411           // GOT entries.
9412           RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9413           return ArmRelocFuncs::STATUS_OKAY;
9414         }
9415       break;
9416
9417     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9418       RelocFuncs::rel32_unaligned(view, value);
9419       return ArmRelocFuncs::STATUS_OKAY;
9420
9421     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9422       if (optimized_type == tls::TLSOPT_NONE)
9423         {
9424           // Relocate the field with the offset of the GOT entry for
9425           // the tp-relative offset of the symbol.
9426           unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9427           unsigned int got_offset;
9428           if (gsym != NULL)
9429             {
9430               gold_assert(gsym->has_got_offset(got_type));
9431               got_offset = gsym->got_offset(got_type);
9432             }
9433           else
9434             {
9435               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9436               gold_assert(object->local_has_got_offset(r_sym, got_type));
9437               got_offset = object->local_got_offset(r_sym, got_type);
9438             }
9439
9440           // All GOT offsets are relative to the end of the GOT.
9441           got_offset -= target->got_size();
9442
9443           Arm_address got_entry =
9444             target->got_plt_section()->address() + got_offset;
9445
9446           // Relocate the field with the PC relative offset of the GOT entry.
9447           RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9448           return ArmRelocFuncs::STATUS_OKAY;
9449         }
9450       break;
9451
9452     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9453       // If we're creating a shared library, a dynamic relocation will
9454       // have been created for this location, so do not apply it now.
9455       if (!parameters->options().shared())
9456         {
9457           gold_assert(tls_segment != NULL);
9458
9459           // $tp points to the TCB, which is followed by the TLS, so we
9460           // need to add TCB size to the offset.
9461           Arm_address aligned_tcb_size =
9462             align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9463           RelocFuncs::rel32_unaligned(view, value + aligned_tcb_size);
9464
9465         }
9466       return ArmRelocFuncs::STATUS_OKAY;
9467
9468     default:
9469       gold_unreachable();
9470     }
9471
9472   gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9473                          _("unsupported reloc %u"),
9474                          r_type);
9475   return ArmRelocFuncs::STATUS_BAD_RELOC;
9476 }
9477
9478 // Relocate section data.
9479
9480 template<bool big_endian>
9481 void
9482 Target_arm<big_endian>::relocate_section(
9483     const Relocate_info<32, big_endian>* relinfo,
9484     unsigned int sh_type,
9485     const unsigned char* prelocs,
9486     size_t reloc_count,
9487     Output_section* output_section,
9488     bool needs_special_offset_handling,
9489     unsigned char* view,
9490     Arm_address address,
9491     section_size_type view_size,
9492     const Reloc_symbol_changes* reloc_symbol_changes)
9493 {
9494   typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
9495   gold_assert(sh_type == elfcpp::SHT_REL);
9496
9497   // See if we are relocating a relaxed input section.  If so, the view
9498   // covers the whole output section and we need to adjust accordingly.
9499   if (needs_special_offset_handling)
9500     {
9501       const Output_relaxed_input_section* poris =
9502         output_section->find_relaxed_input_section(relinfo->object,
9503                                                    relinfo->data_shndx);
9504       if (poris != NULL)
9505         {
9506           Arm_address section_address = poris->address();
9507           section_size_type section_size = poris->data_size();
9508
9509           gold_assert((section_address >= address)
9510                       && ((section_address + section_size)
9511                           <= (address + view_size)));
9512
9513           off_t offset = section_address - address;
9514           view += offset;
9515           address += offset;
9516           view_size = section_size;
9517         }
9518     }
9519
9520   gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
9521                          Arm_relocate, gold::Default_comdat_behavior>(
9522     relinfo,
9523     this,
9524     prelocs,
9525     reloc_count,
9526     output_section,
9527     needs_special_offset_handling,
9528     view,
9529     address,
9530     view_size,
9531     reloc_symbol_changes);
9532 }
9533
9534 // Return the size of a relocation while scanning during a relocatable
9535 // link.
9536
9537 template<bool big_endian>
9538 unsigned int
9539 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
9540     unsigned int r_type,
9541     Relobj* object)
9542 {
9543   r_type = get_real_reloc_type(r_type);
9544   const Arm_reloc_property* arp =
9545       arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9546   if (arp != NULL)
9547     return arp->size();
9548   else
9549     {
9550       std::string reloc_name =
9551         arm_reloc_property_table->reloc_name_in_error_message(r_type);
9552       gold_error(_("%s: unexpected %s in object file"),
9553                  object->name().c_str(), reloc_name.c_str());
9554       return 0;
9555     }
9556 }
9557
9558 // Scan the relocs during a relocatable link.
9559
9560 template<bool big_endian>
9561 void
9562 Target_arm<big_endian>::scan_relocatable_relocs(
9563     Symbol_table* symtab,
9564     Layout* layout,
9565     Sized_relobj_file<32, big_endian>* object,
9566     unsigned int data_shndx,
9567     unsigned int sh_type,
9568     const unsigned char* prelocs,
9569     size_t reloc_count,
9570     Output_section* output_section,
9571     bool needs_special_offset_handling,
9572     size_t local_symbol_count,
9573     const unsigned char* plocal_symbols,
9574     Relocatable_relocs* rr)
9575 {
9576   gold_assert(sh_type == elfcpp::SHT_REL);
9577
9578   typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
9579     Relocatable_size_for_reloc> Scan_relocatable_relocs;
9580
9581   gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
9582       Scan_relocatable_relocs>(
9583     symtab,
9584     layout,
9585     object,
9586     data_shndx,
9587     prelocs,
9588     reloc_count,
9589     output_section,
9590     needs_special_offset_handling,
9591     local_symbol_count,
9592     plocal_symbols,
9593     rr);
9594 }
9595
9596 // Emit relocations for a section.
9597
9598 template<bool big_endian>
9599 void
9600 Target_arm<big_endian>::relocate_relocs(
9601     const Relocate_info<32, big_endian>* relinfo,
9602     unsigned int sh_type,
9603     const unsigned char* prelocs,
9604     size_t reloc_count,
9605     Output_section* output_section,
9606     off_t offset_in_output_section,
9607     const Relocatable_relocs* rr,
9608     unsigned char* view,
9609     Arm_address view_address,
9610     section_size_type view_size,
9611     unsigned char* reloc_view,
9612     section_size_type reloc_view_size)
9613 {
9614   gold_assert(sh_type == elfcpp::SHT_REL);
9615
9616   gold::relocate_relocs<32, big_endian, elfcpp::SHT_REL>(
9617     relinfo,
9618     prelocs,
9619     reloc_count,
9620     output_section,
9621     offset_in_output_section,
9622     rr,
9623     view,
9624     view_address,
9625     view_size,
9626     reloc_view,
9627     reloc_view_size);
9628 }
9629
9630 // Perform target-specific processing in a relocatable link.  This is
9631 // only used if we use the relocation strategy RELOC_SPECIAL.
9632
9633 template<bool big_endian>
9634 void
9635 Target_arm<big_endian>::relocate_special_relocatable(
9636     const Relocate_info<32, big_endian>* relinfo,
9637     unsigned int sh_type,
9638     const unsigned char* preloc_in,
9639     size_t relnum,
9640     Output_section* output_section,
9641     off_t offset_in_output_section,
9642     unsigned char* view,
9643     elfcpp::Elf_types<32>::Elf_Addr view_address,
9644     section_size_type,
9645     unsigned char* preloc_out)
9646 {
9647   // We can only handle REL type relocation sections.
9648   gold_assert(sh_type == elfcpp::SHT_REL);
9649
9650   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
9651   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
9652     Reltype_write;
9653   const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
9654
9655   const Arm_relobj<big_endian>* object =
9656     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9657   const unsigned int local_count = object->local_symbol_count();
9658
9659   Reltype reloc(preloc_in);
9660   Reltype_write reloc_write(preloc_out);
9661
9662   elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
9663   const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9664   const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
9665
9666   const Arm_reloc_property* arp =
9667     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9668   gold_assert(arp != NULL);
9669
9670   // Get the new symbol index.
9671   // We only use RELOC_SPECIAL strategy in local relocations.
9672   gold_assert(r_sym < local_count);
9673
9674   // We are adjusting a section symbol.  We need to find
9675   // the symbol table index of the section symbol for
9676   // the output section corresponding to input section
9677   // in which this symbol is defined.
9678   bool is_ordinary;
9679   unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
9680   gold_assert(is_ordinary);
9681   Output_section* os = object->output_section(shndx);
9682   gold_assert(os != NULL);
9683   gold_assert(os->needs_symtab_index());
9684   unsigned int new_symndx = os->symtab_index();
9685
9686   // Get the new offset--the location in the output section where
9687   // this relocation should be applied.
9688
9689   Arm_address offset = reloc.get_r_offset();
9690   Arm_address new_offset;
9691   if (offset_in_output_section != invalid_address)
9692     new_offset = offset + offset_in_output_section;
9693   else
9694     {
9695       section_offset_type sot_offset =
9696           convert_types<section_offset_type, Arm_address>(offset);
9697       section_offset_type new_sot_offset =
9698           output_section->output_offset(object, relinfo->data_shndx,
9699                                         sot_offset);
9700       gold_assert(new_sot_offset != -1);
9701       new_offset = new_sot_offset;
9702     }
9703
9704   // In an object file, r_offset is an offset within the section.
9705   // In an executable or dynamic object, generated by
9706   // --emit-relocs, r_offset is an absolute address.
9707   if (!parameters->options().relocatable())
9708     {
9709       new_offset += view_address;
9710       if (offset_in_output_section != invalid_address)
9711         new_offset -= offset_in_output_section;
9712     }
9713
9714   reloc_write.put_r_offset(new_offset);
9715   reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
9716
9717   // Handle the reloc addend.
9718   // The relocation uses a section symbol in the input file.
9719   // We are adjusting it to use a section symbol in the output
9720   // file.  The input section symbol refers to some address in
9721   // the input section.  We need the relocation in the output
9722   // file to refer to that same address.  This adjustment to
9723   // the addend is the same calculation we use for a simple
9724   // absolute relocation for the input section symbol.
9725
9726   const Symbol_value<32>* psymval = object->local_symbol(r_sym);
9727
9728   // Handle THUMB bit.
9729   Symbol_value<32> symval;
9730   Arm_address thumb_bit =
9731      object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9732   if (thumb_bit != 0
9733       && arp->uses_thumb_bit()
9734       && ((psymval->value(object, 0) & 1) != 0))
9735     {
9736       Arm_address stripped_value =
9737         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9738       symval.set_output_value(stripped_value);
9739       psymval = &symval;
9740     }
9741
9742   unsigned char* paddend = view + offset;
9743   typename Arm_relocate_functions<big_endian>::Status reloc_status =
9744         Arm_relocate_functions<big_endian>::STATUS_OKAY;
9745   switch (r_type)
9746     {
9747     case elfcpp::R_ARM_ABS8:
9748       reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
9749                                                               psymval);
9750       break;
9751
9752     case elfcpp::R_ARM_ABS12:
9753       reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
9754                                                                psymval);
9755       break;
9756
9757     case elfcpp::R_ARM_ABS16:
9758       reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
9759                                                                psymval);
9760       break;
9761
9762     case elfcpp::R_ARM_THM_ABS5:
9763       reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
9764                                                                   object,
9765                                                                   psymval);
9766       break;
9767
9768     case elfcpp::R_ARM_MOVW_ABS_NC:
9769     case elfcpp::R_ARM_MOVW_PREL_NC:
9770     case elfcpp::R_ARM_MOVW_BREL_NC:
9771     case elfcpp::R_ARM_MOVW_BREL:
9772       reloc_status = Arm_relocate_functions<big_endian>::movw(
9773           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9774       break;
9775
9776     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9777     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9778     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9779     case elfcpp::R_ARM_THM_MOVW_BREL:
9780       reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
9781           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9782       break;
9783
9784     case elfcpp::R_ARM_THM_CALL:
9785     case elfcpp::R_ARM_THM_XPC22:
9786     case elfcpp::R_ARM_THM_JUMP24:
9787       reloc_status =
9788         Arm_relocate_functions<big_endian>::thumb_branch_common(
9789             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9790             false);
9791       break;
9792
9793     case elfcpp::R_ARM_PLT32:
9794     case elfcpp::R_ARM_CALL:
9795     case elfcpp::R_ARM_JUMP24:
9796     case elfcpp::R_ARM_XPC25:
9797       reloc_status =
9798         Arm_relocate_functions<big_endian>::arm_branch_common(
9799             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9800             false);
9801       break;
9802
9803     case elfcpp::R_ARM_THM_JUMP19:
9804       reloc_status =
9805         Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
9806                                                        psymval, 0, thumb_bit);
9807       break;
9808
9809     case elfcpp::R_ARM_THM_JUMP6:
9810       reloc_status =
9811         Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
9812                                                       0);
9813       break;
9814
9815     case elfcpp::R_ARM_THM_JUMP8:
9816       reloc_status =
9817         Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
9818                                                       0);
9819       break;
9820
9821     case elfcpp::R_ARM_THM_JUMP11:
9822       reloc_status =
9823         Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
9824                                                        0);
9825       break;
9826
9827     case elfcpp::R_ARM_PREL31:
9828       reloc_status =
9829         Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
9830                                                    thumb_bit);
9831       break;
9832
9833     case elfcpp::R_ARM_THM_PC8:
9834       reloc_status =
9835         Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
9836                                                     0);
9837       break;
9838
9839     case elfcpp::R_ARM_THM_PC12:
9840       reloc_status =
9841         Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
9842                                                      0);
9843       break;
9844
9845     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9846       reloc_status =
9847         Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
9848                                                       0, thumb_bit);
9849       break;
9850
9851     // These relocation truncate relocation results so we cannot handle them
9852     // in a relocatable link.
9853     case elfcpp::R_ARM_MOVT_ABS:
9854     case elfcpp::R_ARM_THM_MOVT_ABS:
9855     case elfcpp::R_ARM_MOVT_PREL:
9856     case elfcpp::R_ARM_MOVT_BREL:
9857     case elfcpp::R_ARM_THM_MOVT_PREL:
9858     case elfcpp::R_ARM_THM_MOVT_BREL:
9859     case elfcpp::R_ARM_ALU_PC_G0_NC:
9860     case elfcpp::R_ARM_ALU_PC_G0:
9861     case elfcpp::R_ARM_ALU_PC_G1_NC:
9862     case elfcpp::R_ARM_ALU_PC_G1:
9863     case elfcpp::R_ARM_ALU_PC_G2:
9864     case elfcpp::R_ARM_ALU_SB_G0_NC:
9865     case elfcpp::R_ARM_ALU_SB_G0:
9866     case elfcpp::R_ARM_ALU_SB_G1_NC:
9867     case elfcpp::R_ARM_ALU_SB_G1:
9868     case elfcpp::R_ARM_ALU_SB_G2:
9869     case elfcpp::R_ARM_LDR_PC_G0:
9870     case elfcpp::R_ARM_LDR_PC_G1:
9871     case elfcpp::R_ARM_LDR_PC_G2:
9872     case elfcpp::R_ARM_LDR_SB_G0:
9873     case elfcpp::R_ARM_LDR_SB_G1:
9874     case elfcpp::R_ARM_LDR_SB_G2:
9875     case elfcpp::R_ARM_LDRS_PC_G0:
9876     case elfcpp::R_ARM_LDRS_PC_G1:
9877     case elfcpp::R_ARM_LDRS_PC_G2:
9878     case elfcpp::R_ARM_LDRS_SB_G0:
9879     case elfcpp::R_ARM_LDRS_SB_G1:
9880     case elfcpp::R_ARM_LDRS_SB_G2:
9881     case elfcpp::R_ARM_LDC_PC_G0:
9882     case elfcpp::R_ARM_LDC_PC_G1:
9883     case elfcpp::R_ARM_LDC_PC_G2:
9884     case elfcpp::R_ARM_LDC_SB_G0:
9885     case elfcpp::R_ARM_LDC_SB_G1:
9886     case elfcpp::R_ARM_LDC_SB_G2:
9887       gold_error(_("cannot handle %s in a relocatable link"),
9888                  arp->name().c_str());
9889       break;
9890
9891     default:
9892       gold_unreachable();
9893     }
9894
9895   // Report any errors.
9896   switch (reloc_status)
9897     {
9898     case Arm_relocate_functions<big_endian>::STATUS_OKAY:
9899       break;
9900     case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
9901       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9902                              _("relocation overflow in %s"),
9903                              arp->name().c_str());
9904       break;
9905     case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
9906       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9907         _("unexpected opcode while processing relocation %s"),
9908         arp->name().c_str());
9909       break;
9910     default:
9911       gold_unreachable();
9912     }
9913 }
9914
9915 // Return the value to use for a dynamic symbol which requires special
9916 // treatment.  This is how we support equality comparisons of function
9917 // pointers across shared library boundaries, as described in the
9918 // processor specific ABI supplement.
9919
9920 template<bool big_endian>
9921 uint64_t
9922 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
9923 {
9924   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
9925   return this->plt_section()->address() + gsym->plt_offset();
9926 }
9927
9928 // Map platform-specific relocs to real relocs
9929 //
9930 template<bool big_endian>
9931 unsigned int
9932 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
9933 {
9934   switch (r_type)
9935     {
9936     case elfcpp::R_ARM_TARGET1:
9937       // This is either R_ARM_ABS32 or R_ARM_REL32;
9938       return elfcpp::R_ARM_ABS32;
9939
9940     case elfcpp::R_ARM_TARGET2:
9941       // This can be any reloc type but usually is R_ARM_GOT_PREL
9942       return elfcpp::R_ARM_GOT_PREL;
9943
9944     default:
9945       return r_type;
9946     }
9947 }
9948
9949 // Whether if two EABI versions V1 and V2 are compatible.
9950
9951 template<bool big_endian>
9952 bool
9953 Target_arm<big_endian>::are_eabi_versions_compatible(
9954     elfcpp::Elf_Word v1,
9955     elfcpp::Elf_Word v2)
9956 {
9957   // v4 and v5 are the same spec before and after it was released,
9958   // so allow mixing them.
9959   if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
9960       || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
9961       || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
9962     return true;
9963
9964   return v1 == v2;
9965 }
9966
9967 // Combine FLAGS from an input object called NAME and the processor-specific
9968 // flags in the ELF header of the output.  Much of this is adapted from the
9969 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
9970 // in bfd/elf32-arm.c.
9971
9972 template<bool big_endian>
9973 void
9974 Target_arm<big_endian>::merge_processor_specific_flags(
9975     const std::string& name,
9976     elfcpp::Elf_Word flags)
9977 {
9978   if (this->are_processor_specific_flags_set())
9979     {
9980       elfcpp::Elf_Word out_flags = this->processor_specific_flags();
9981
9982       // Nothing to merge if flags equal to those in output.
9983       if (flags == out_flags)
9984         return;
9985
9986       // Complain about various flag mismatches.
9987       elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
9988       elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
9989       if (!this->are_eabi_versions_compatible(version1, version2)
9990           && parameters->options().warn_mismatch())
9991         gold_error(_("Source object %s has EABI version %d but output has "
9992                      "EABI version %d."),
9993                    name.c_str(),
9994                    (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
9995                    (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
9996     }
9997   else
9998     {
9999       // If the input is the default architecture and had the default
10000       // flags then do not bother setting the flags for the output
10001       // architecture, instead allow future merges to do this.  If no
10002       // future merges ever set these flags then they will retain their
10003       // uninitialised values, which surprise surprise, correspond
10004       // to the default values.
10005       if (flags == 0)
10006         return;
10007
10008       // This is the first time, just copy the flags.
10009       // We only copy the EABI version for now.
10010       this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
10011     }
10012 }
10013
10014 // Adjust ELF file header.
10015 template<bool big_endian>
10016 void
10017 Target_arm<big_endian>::do_adjust_elf_header(
10018     unsigned char* view,
10019     int len) const
10020 {
10021   gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
10022
10023   elfcpp::Ehdr<32, big_endian> ehdr(view);
10024   unsigned char e_ident[elfcpp::EI_NIDENT];
10025   memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
10026
10027   if (elfcpp::arm_eabi_version(this->processor_specific_flags())
10028       == elfcpp::EF_ARM_EABI_UNKNOWN)
10029     e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
10030   else
10031     e_ident[elfcpp::EI_OSABI] = 0;
10032   e_ident[elfcpp::EI_ABIVERSION] = 0;
10033
10034   // FIXME: Do EF_ARM_BE8 adjustment.
10035
10036   elfcpp::Ehdr_write<32, big_endian> oehdr(view);
10037   oehdr.put_e_ident(e_ident);
10038 }
10039
10040 // do_make_elf_object to override the same function in the base class.
10041 // We need to use a target-specific sub-class of
10042 // Sized_relobj_file<32, big_endian> to store ARM specific information.
10043 // Hence we need to have our own ELF object creation.
10044
10045 template<bool big_endian>
10046 Object*
10047 Target_arm<big_endian>::do_make_elf_object(
10048     const std::string& name,
10049     Input_file* input_file,
10050     off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
10051 {
10052   int et = ehdr.get_e_type();
10053   // ET_EXEC files are valid input for --just-symbols/-R,
10054   // and we treat them as relocatable objects.
10055   if (et == elfcpp::ET_REL
10056       || (et == elfcpp::ET_EXEC && input_file->just_symbols()))
10057     {
10058       Arm_relobj<big_endian>* obj =
10059         new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
10060       obj->setup();
10061       return obj;
10062     }
10063   else if (et == elfcpp::ET_DYN)
10064     {
10065       Sized_dynobj<32, big_endian>* obj =
10066         new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
10067       obj->setup();
10068       return obj;
10069     }
10070   else
10071     {
10072       gold_error(_("%s: unsupported ELF file type %d"),
10073                  name.c_str(), et);
10074       return NULL;
10075     }
10076 }
10077
10078 // Read the architecture from the Tag_also_compatible_with attribute, if any.
10079 // Returns -1 if no architecture could be read.
10080 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
10081
10082 template<bool big_endian>
10083 int
10084 Target_arm<big_endian>::get_secondary_compatible_arch(
10085     const Attributes_section_data* pasd)
10086 {
10087   const Object_attribute* known_attributes =
10088     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10089
10090   // Note: the tag and its argument below are uleb128 values, though
10091   // currently-defined values fit in one byte for each.
10092   const std::string& sv =
10093     known_attributes[elfcpp::Tag_also_compatible_with].string_value();
10094   if (sv.size() == 2
10095       && sv.data()[0] == elfcpp::Tag_CPU_arch
10096       && (sv.data()[1] & 128) != 128)
10097    return sv.data()[1];
10098
10099   // This tag is "safely ignorable", so don't complain if it looks funny.
10100   return -1;
10101 }
10102
10103 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10104 // The tag is removed if ARCH is -1.
10105 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10106
10107 template<bool big_endian>
10108 void
10109 Target_arm<big_endian>::set_secondary_compatible_arch(
10110     Attributes_section_data* pasd,
10111     int arch)
10112 {
10113   Object_attribute* known_attributes =
10114     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10115
10116   if (arch == -1)
10117     {
10118       known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10119       return;
10120     }
10121
10122   // Note: the tag and its argument below are uleb128 values, though
10123   // currently-defined values fit in one byte for each.
10124   char sv[3];
10125   sv[0] = elfcpp::Tag_CPU_arch;
10126   gold_assert(arch != 0);
10127   sv[1] = arch;
10128   sv[2] = '\0';
10129
10130   known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10131 }
10132
10133 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10134 // into account.
10135 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10136
10137 template<bool big_endian>
10138 int
10139 Target_arm<big_endian>::tag_cpu_arch_combine(
10140     const char* name,
10141     int oldtag,
10142     int* secondary_compat_out,
10143     int newtag,
10144     int secondary_compat)
10145 {
10146 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10147   static const int v6t2[] =
10148     {
10149       T(V6T2),   // PRE_V4.
10150       T(V6T2),   // V4.
10151       T(V6T2),   // V4T.
10152       T(V6T2),   // V5T.
10153       T(V6T2),   // V5TE.
10154       T(V6T2),   // V5TEJ.
10155       T(V6T2),   // V6.
10156       T(V7),     // V6KZ.
10157       T(V6T2)    // V6T2.
10158     };
10159   static const int v6k[] =
10160     {
10161       T(V6K),    // PRE_V4.
10162       T(V6K),    // V4.
10163       T(V6K),    // V4T.
10164       T(V6K),    // V5T.
10165       T(V6K),    // V5TE.
10166       T(V6K),    // V5TEJ.
10167       T(V6K),    // V6.
10168       T(V6KZ),   // V6KZ.
10169       T(V7),     // V6T2.
10170       T(V6K)     // V6K.
10171     };
10172   static const int v7[] =
10173     {
10174       T(V7),     // PRE_V4.
10175       T(V7),     // V4.
10176       T(V7),     // V4T.
10177       T(V7),     // V5T.
10178       T(V7),     // V5TE.
10179       T(V7),     // V5TEJ.
10180       T(V7),     // V6.
10181       T(V7),     // V6KZ.
10182       T(V7),     // V6T2.
10183       T(V7),     // V6K.
10184       T(V7)      // V7.
10185     };
10186   static const int v6_m[] =
10187     {
10188       -1,        // PRE_V4.
10189       -1,        // V4.
10190       T(V6K),    // V4T.
10191       T(V6K),    // V5T.
10192       T(V6K),    // V5TE.
10193       T(V6K),    // V5TEJ.
10194       T(V6K),    // V6.
10195       T(V6KZ),   // V6KZ.
10196       T(V7),     // V6T2.
10197       T(V6K),    // V6K.
10198       T(V7),     // V7.
10199       T(V6_M)    // V6_M.
10200     };
10201   static const int v6s_m[] =
10202     {
10203       -1,        // PRE_V4.
10204       -1,        // V4.
10205       T(V6K),    // V4T.
10206       T(V6K),    // V5T.
10207       T(V6K),    // V5TE.
10208       T(V6K),    // V5TEJ.
10209       T(V6K),    // V6.
10210       T(V6KZ),   // V6KZ.
10211       T(V7),     // V6T2.
10212       T(V6K),    // V6K.
10213       T(V7),     // V7.
10214       T(V6S_M),  // V6_M.
10215       T(V6S_M)   // V6S_M.
10216     };
10217   static const int v7e_m[] =
10218     {
10219       -1,       // PRE_V4.
10220       -1,       // V4.
10221       T(V7E_M), // V4T.
10222       T(V7E_M), // V5T.
10223       T(V7E_M), // V5TE.
10224       T(V7E_M), // V5TEJ.
10225       T(V7E_M), // V6.
10226       T(V7E_M), // V6KZ.
10227       T(V7E_M), // V6T2.
10228       T(V7E_M), // V6K.
10229       T(V7E_M), // V7.
10230       T(V7E_M), // V6_M.
10231       T(V7E_M), // V6S_M.
10232       T(V7E_M)  // V7E_M.
10233     };
10234   static const int v4t_plus_v6_m[] =
10235     {
10236       -1,               // PRE_V4.
10237       -1,               // V4.
10238       T(V4T),           // V4T.
10239       T(V5T),           // V5T.
10240       T(V5TE),          // V5TE.
10241       T(V5TEJ),         // V5TEJ.
10242       T(V6),            // V6.
10243       T(V6KZ),          // V6KZ.
10244       T(V6T2),          // V6T2.
10245       T(V6K),           // V6K.
10246       T(V7),            // V7.
10247       T(V6_M),          // V6_M.
10248       T(V6S_M),         // V6S_M.
10249       T(V7E_M),         // V7E_M.
10250       T(V4T_PLUS_V6_M)  // V4T plus V6_M.
10251     };
10252   static const int* comb[] =
10253     {
10254       v6t2,
10255       v6k,
10256       v7,
10257       v6_m,
10258       v6s_m,
10259       v7e_m,
10260       // Pseudo-architecture.
10261       v4t_plus_v6_m
10262     };
10263
10264   // Check we've not got a higher architecture than we know about.
10265
10266   if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
10267     {
10268       gold_error(_("%s: unknown CPU architecture"), name);
10269       return -1;
10270     }
10271
10272   // Override old tag if we have a Tag_also_compatible_with on the output.
10273
10274   if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10275       || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10276     oldtag = T(V4T_PLUS_V6_M);
10277
10278   // And override the new tag if we have a Tag_also_compatible_with on the
10279   // input.
10280
10281   if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10282       || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10283     newtag = T(V4T_PLUS_V6_M);
10284
10285   // Architectures before V6KZ add features monotonically.
10286   int tagh = std::max(oldtag, newtag);
10287   if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10288     return tagh;
10289
10290   int tagl = std::min(oldtag, newtag);
10291   int result = comb[tagh - T(V6T2)][tagl];
10292
10293   // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10294   // as the canonical version.
10295   if (result == T(V4T_PLUS_V6_M))
10296     {
10297       result = T(V4T);
10298       *secondary_compat_out = T(V6_M);
10299     }
10300   else
10301     *secondary_compat_out = -1;
10302
10303   if (result == -1)
10304     {
10305       gold_error(_("%s: conflicting CPU architectures %d/%d"),
10306                  name, oldtag, newtag);
10307       return -1;
10308     }
10309
10310   return result;
10311 #undef T
10312 }
10313
10314 // Helper to print AEABI enum tag value.
10315
10316 template<bool big_endian>
10317 std::string
10318 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10319 {
10320   static const char* aeabi_enum_names[] =
10321     { "", "variable-size", "32-bit", "" };
10322   const size_t aeabi_enum_names_size =
10323     sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10324
10325   if (value < aeabi_enum_names_size)
10326     return std::string(aeabi_enum_names[value]);
10327   else
10328     {
10329       char buffer[100];
10330       sprintf(buffer, "<unknown value %u>", value);
10331       return std::string(buffer);
10332     }
10333 }
10334
10335 // Return the string value to store in TAG_CPU_name.
10336
10337 template<bool big_endian>
10338 std::string
10339 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10340 {
10341   static const char* name_table[] = {
10342     // These aren't real CPU names, but we can't guess
10343     // that from the architecture version alone.
10344    "Pre v4",
10345    "ARM v4",
10346    "ARM v4T",
10347    "ARM v5T",
10348    "ARM v5TE",
10349    "ARM v5TEJ",
10350    "ARM v6",
10351    "ARM v6KZ",
10352    "ARM v6T2",
10353    "ARM v6K",
10354    "ARM v7",
10355    "ARM v6-M",
10356    "ARM v6S-M",
10357    "ARM v7E-M"
10358  };
10359  const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10360
10361   if (value < name_table_size)
10362     return std::string(name_table[value]);
10363   else
10364     {
10365       char buffer[100];
10366       sprintf(buffer, "<unknown CPU value %u>", value);
10367       return std::string(buffer);
10368     }
10369 }
10370
10371 // Merge object attributes from input file called NAME with those of the
10372 // output.  The input object attributes are in the object pointed by PASD.
10373
10374 template<bool big_endian>
10375 void
10376 Target_arm<big_endian>::merge_object_attributes(
10377     const char* name,
10378     const Attributes_section_data* pasd)
10379 {
10380   // Return if there is no attributes section data.
10381   if (pasd == NULL)
10382     return;
10383
10384   // If output has no object attributes, just copy.
10385   const int vendor = Object_attribute::OBJ_ATTR_PROC;
10386   if (this->attributes_section_data_ == NULL)
10387     {
10388       this->attributes_section_data_ = new Attributes_section_data(*pasd);
10389       Object_attribute* out_attr =
10390         this->attributes_section_data_->known_attributes(vendor);
10391
10392       // We do not output objects with Tag_MPextension_use_legacy - we move
10393       //  the attribute's value to Tag_MPextension_use.  */
10394       if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10395         {
10396           if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10397               && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10398                 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10399             {
10400               gold_error(_("%s has both the current and legacy "
10401                            "Tag_MPextension_use attributes"),
10402                          name);
10403             }
10404
10405           out_attr[elfcpp::Tag_MPextension_use] =
10406             out_attr[elfcpp::Tag_MPextension_use_legacy];
10407           out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10408           out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10409         }
10410
10411       return;
10412     }
10413
10414   const Object_attribute* in_attr = pasd->known_attributes(vendor);
10415   Object_attribute* out_attr =
10416     this->attributes_section_data_->known_attributes(vendor);
10417
10418   // This needs to happen before Tag_ABI_FP_number_model is merged.  */
10419   if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10420       != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
10421     {
10422       // Ignore mismatches if the object doesn't use floating point.  */
10423       if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
10424         out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10425             in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10426       else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
10427                && parameters->options().warn_mismatch())
10428         gold_error(_("%s uses VFP register arguments, output does not"),
10429                    name);
10430     }
10431
10432   for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10433     {
10434       // Merge this attribute with existing attributes.
10435       switch (i)
10436         {
10437         case elfcpp::Tag_CPU_raw_name:
10438         case elfcpp::Tag_CPU_name:
10439           // These are merged after Tag_CPU_arch.
10440           break;
10441
10442         case elfcpp::Tag_ABI_optimization_goals:
10443         case elfcpp::Tag_ABI_FP_optimization_goals:
10444           // Use the first value seen.
10445           break;
10446
10447         case elfcpp::Tag_CPU_arch:
10448           {
10449             unsigned int saved_out_attr = out_attr->int_value();
10450             // Merge Tag_CPU_arch and Tag_also_compatible_with.
10451             int secondary_compat =
10452               this->get_secondary_compatible_arch(pasd);
10453             int secondary_compat_out =
10454               this->get_secondary_compatible_arch(
10455                   this->attributes_section_data_);
10456             out_attr[i].set_int_value(
10457                 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10458                                      &secondary_compat_out,
10459                                      in_attr[i].int_value(),
10460                                      secondary_compat));
10461             this->set_secondary_compatible_arch(this->attributes_section_data_,
10462                                                 secondary_compat_out);
10463
10464             // Merge Tag_CPU_name and Tag_CPU_raw_name.
10465             if (out_attr[i].int_value() == saved_out_attr)
10466               ; // Leave the names alone.
10467             else if (out_attr[i].int_value() == in_attr[i].int_value())
10468               {
10469                 // The output architecture has been changed to match the
10470                 // input architecture.  Use the input names.
10471                 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10472                     in_attr[elfcpp::Tag_CPU_name].string_value());
10473                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10474                     in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10475               }
10476             else
10477               {
10478                 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10479                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10480               }
10481
10482             // If we still don't have a value for Tag_CPU_name,
10483             // make one up now.  Tag_CPU_raw_name remains blank.
10484             if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10485               {
10486                 const std::string cpu_name =
10487                   this->tag_cpu_name_value(out_attr[i].int_value());
10488                 // FIXME:  If we see an unknown CPU, this will be set
10489                 // to "<unknown CPU n>", where n is the attribute value.
10490                 // This is different from BFD, which leaves the name alone.
10491                 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10492               }
10493           }
10494           break;
10495
10496         case elfcpp::Tag_ARM_ISA_use:
10497         case elfcpp::Tag_THUMB_ISA_use:
10498         case elfcpp::Tag_WMMX_arch:
10499         case elfcpp::Tag_Advanced_SIMD_arch:
10500           // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10501         case elfcpp::Tag_ABI_FP_rounding:
10502         case elfcpp::Tag_ABI_FP_exceptions:
10503         case elfcpp::Tag_ABI_FP_user_exceptions:
10504         case elfcpp::Tag_ABI_FP_number_model:
10505         case elfcpp::Tag_VFP_HP_extension:
10506         case elfcpp::Tag_CPU_unaligned_access:
10507         case elfcpp::Tag_T2EE_use:
10508         case elfcpp::Tag_Virtualization_use:
10509         case elfcpp::Tag_MPextension_use:
10510           // Use the largest value specified.
10511           if (in_attr[i].int_value() > out_attr[i].int_value())
10512             out_attr[i].set_int_value(in_attr[i].int_value());
10513           break;
10514
10515         case elfcpp::Tag_ABI_align8_preserved:
10516         case elfcpp::Tag_ABI_PCS_RO_data:
10517           // Use the smallest value specified.
10518           if (in_attr[i].int_value() < out_attr[i].int_value())
10519             out_attr[i].set_int_value(in_attr[i].int_value());
10520           break;
10521
10522         case elfcpp::Tag_ABI_align8_needed:
10523           if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10524               && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10525                   || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10526                       == 0)))
10527             {
10528               // This error message should be enabled once all non-conforming
10529               // binaries in the toolchain have had the attributes set
10530               // properly.
10531               // gold_error(_("output 8-byte data alignment conflicts with %s"),
10532               //            name);
10533             }
10534           // Fall through.
10535         case elfcpp::Tag_ABI_FP_denormal:
10536         case elfcpp::Tag_ABI_PCS_GOT_use:
10537           {
10538             // These tags have 0 = don't care, 1 = strong requirement,
10539             // 2 = weak requirement.
10540             static const int order_021[3] = {0, 2, 1};
10541
10542             // Use the "greatest" from the sequence 0, 2, 1, or the largest
10543             // value if greater than 2 (for future-proofing).
10544             if ((in_attr[i].int_value() > 2
10545                  && in_attr[i].int_value() > out_attr[i].int_value())
10546                 || (in_attr[i].int_value() <= 2
10547                     && out_attr[i].int_value() <= 2
10548                     && (order_021[in_attr[i].int_value()]
10549                         > order_021[out_attr[i].int_value()])))
10550               out_attr[i].set_int_value(in_attr[i].int_value());
10551           }
10552           break;
10553
10554         case elfcpp::Tag_CPU_arch_profile:
10555           if (out_attr[i].int_value() != in_attr[i].int_value())
10556             {
10557               // 0 will merge with anything.
10558               // 'A' and 'S' merge to 'A'.
10559               // 'R' and 'S' merge to 'R'.
10560               // 'M' and 'A|R|S' is an error.
10561               if (out_attr[i].int_value() == 0
10562                   || (out_attr[i].int_value() == 'S'
10563                       && (in_attr[i].int_value() == 'A'
10564                           || in_attr[i].int_value() == 'R')))
10565                 out_attr[i].set_int_value(in_attr[i].int_value());
10566               else if (in_attr[i].int_value() == 0
10567                        || (in_attr[i].int_value() == 'S'
10568                            && (out_attr[i].int_value() == 'A'
10569                                || out_attr[i].int_value() == 'R')))
10570                 ; // Do nothing.
10571               else if (parameters->options().warn_mismatch())
10572                 {
10573                   gold_error
10574                     (_("conflicting architecture profiles %c/%c"),
10575                      in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10576                      out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10577                 }
10578             }
10579           break;
10580         case elfcpp::Tag_VFP_arch:
10581             {
10582               static const struct
10583               {
10584                   int ver;
10585                   int regs;
10586               } vfp_versions[7] =
10587                 {
10588                   {0, 0},
10589                   {1, 16},
10590                   {2, 16},
10591                   {3, 32},
10592                   {3, 16},
10593                   {4, 32},
10594                   {4, 16}
10595                 };
10596
10597               // Values greater than 6 aren't defined, so just pick the
10598               // biggest.
10599               if (in_attr[i].int_value() > 6
10600                   && in_attr[i].int_value() > out_attr[i].int_value())
10601                 {
10602                   *out_attr = *in_attr;
10603                   break;
10604                 }
10605               // The output uses the superset of input features
10606               // (ISA version) and registers.
10607               int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10608                                  vfp_versions[out_attr[i].int_value()].ver);
10609               int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10610                                   vfp_versions[out_attr[i].int_value()].regs);
10611               // This assumes all possible supersets are also a valid
10612               // options.
10613               int newval;
10614               for (newval = 6; newval > 0; newval--)
10615                 {
10616                   if (regs == vfp_versions[newval].regs
10617                       && ver == vfp_versions[newval].ver)
10618                     break;
10619                 }
10620               out_attr[i].set_int_value(newval);
10621             }
10622           break;
10623         case elfcpp::Tag_PCS_config:
10624           if (out_attr[i].int_value() == 0)
10625             out_attr[i].set_int_value(in_attr[i].int_value());
10626           else if (in_attr[i].int_value() != 0
10627                    && out_attr[i].int_value() != 0
10628                    && parameters->options().warn_mismatch())
10629             {
10630               // It's sometimes ok to mix different configs, so this is only
10631               // a warning.
10632               gold_warning(_("%s: conflicting platform configuration"), name);
10633             }
10634           break;
10635         case elfcpp::Tag_ABI_PCS_R9_use:
10636           if (in_attr[i].int_value() != out_attr[i].int_value()
10637               && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10638               && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10639               && parameters->options().warn_mismatch())
10640             {
10641               gold_error(_("%s: conflicting use of R9"), name);
10642             }
10643           if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10644             out_attr[i].set_int_value(in_attr[i].int_value());
10645           break;
10646         case elfcpp::Tag_ABI_PCS_RW_data:
10647           if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10648               && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10649                   != elfcpp::AEABI_R9_SB)
10650               && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10651                   != elfcpp::AEABI_R9_unused)
10652               && parameters->options().warn_mismatch())
10653             {
10654               gold_error(_("%s: SB relative addressing conflicts with use "
10655                            "of R9"),
10656                            name);
10657             }
10658           // Use the smallest value specified.
10659           if (in_attr[i].int_value() < out_attr[i].int_value())
10660             out_attr[i].set_int_value(in_attr[i].int_value());
10661           break;
10662         case elfcpp::Tag_ABI_PCS_wchar_t:
10663           if (out_attr[i].int_value()
10664               && in_attr[i].int_value()
10665               && out_attr[i].int_value() != in_attr[i].int_value()
10666               && parameters->options().warn_mismatch()
10667               && parameters->options().wchar_size_warning())
10668             {
10669               gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10670                              "use %u-byte wchar_t; use of wchar_t values "
10671                              "across objects may fail"),
10672                            name, in_attr[i].int_value(),
10673                            out_attr[i].int_value());
10674             }
10675           else if (in_attr[i].int_value() && !out_attr[i].int_value())
10676             out_attr[i].set_int_value(in_attr[i].int_value());
10677           break;
10678         case elfcpp::Tag_ABI_enum_size:
10679           if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10680             {
10681               if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10682                   || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10683                 {
10684                   // The existing object is compatible with anything.
10685                   // Use whatever requirements the new object has.
10686                   out_attr[i].set_int_value(in_attr[i].int_value());
10687                 }
10688               else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10689                        && out_attr[i].int_value() != in_attr[i].int_value()
10690                        && parameters->options().warn_mismatch()
10691                        && parameters->options().enum_size_warning())
10692                 {
10693                   unsigned int in_value = in_attr[i].int_value();
10694                   unsigned int out_value = out_attr[i].int_value();
10695                   gold_warning(_("%s uses %s enums yet the output is to use "
10696                                  "%s enums; use of enum values across objects "
10697                                  "may fail"),
10698                                name,
10699                                this->aeabi_enum_name(in_value).c_str(),
10700                                this->aeabi_enum_name(out_value).c_str());
10701                 }
10702             }
10703           break;
10704         case elfcpp::Tag_ABI_VFP_args:
10705           // Already done.
10706           break;
10707         case elfcpp::Tag_ABI_WMMX_args:
10708           if (in_attr[i].int_value() != out_attr[i].int_value()
10709               && parameters->options().warn_mismatch())
10710             {
10711               gold_error(_("%s uses iWMMXt register arguments, output does "
10712                            "not"),
10713                          name);
10714             }
10715           break;
10716         case Object_attribute::Tag_compatibility:
10717           // Merged in target-independent code.
10718           break;
10719         case elfcpp::Tag_ABI_HardFP_use:
10720           // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10721           if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10722               || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10723             out_attr[i].set_int_value(3);
10724           else if (in_attr[i].int_value() > out_attr[i].int_value())
10725             out_attr[i].set_int_value(in_attr[i].int_value());
10726           break;
10727         case elfcpp::Tag_ABI_FP_16bit_format:
10728           if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10729             {
10730               if (in_attr[i].int_value() != out_attr[i].int_value()
10731                   && parameters->options().warn_mismatch())
10732                 gold_error(_("fp16 format mismatch between %s and output"),
10733                            name);
10734             }
10735           if (in_attr[i].int_value() != 0)
10736             out_attr[i].set_int_value(in_attr[i].int_value());
10737           break;
10738
10739         case elfcpp::Tag_DIV_use:
10740           // This tag is set to zero if we can use UDIV and SDIV in Thumb
10741           // mode on a v7-M or v7-R CPU; to one if we can not use UDIV or
10742           // SDIV at all; and to two if we can use UDIV or SDIV on a v7-A
10743           // CPU.  We will merge as follows: If the input attribute's value
10744           // is one then the output attribute's value remains unchanged.  If
10745           // the input attribute's value is zero or two then if the output
10746           // attribute's value is one the output value is set to the input
10747           // value, otherwise the output value must be the same as the
10748           // inputs.  */
10749           if (in_attr[i].int_value() != 1 && out_attr[i].int_value() != 1)
10750             {
10751               if (in_attr[i].int_value() != out_attr[i].int_value())
10752                 {
10753                   gold_error(_("DIV usage mismatch between %s and output"),
10754                              name);
10755                 }
10756             }
10757
10758           if (in_attr[i].int_value() != 1)
10759             out_attr[i].set_int_value(in_attr[i].int_value());
10760
10761           break;
10762
10763         case elfcpp::Tag_MPextension_use_legacy:
10764           // We don't output objects with Tag_MPextension_use_legacy - we
10765           // move the value to Tag_MPextension_use.
10766           if (in_attr[i].int_value() != 0
10767               && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10768             {
10769               if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10770                   != in_attr[i].int_value())
10771                 {
10772                   gold_error(_("%s has has both the current and legacy "
10773                                "Tag_MPextension_use attributes"),
10774                              name);
10775                 }
10776             }
10777
10778           if (in_attr[i].int_value()
10779               > out_attr[elfcpp::Tag_MPextension_use].int_value())
10780             out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10781
10782           break;
10783
10784         case elfcpp::Tag_nodefaults:
10785           // This tag is set if it exists, but the value is unused (and is
10786           // typically zero).  We don't actually need to do anything here -
10787           // the merge happens automatically when the type flags are merged
10788           // below.
10789           break;
10790         case elfcpp::Tag_also_compatible_with:
10791           // Already done in Tag_CPU_arch.
10792           break;
10793         case elfcpp::Tag_conformance:
10794           // Keep the attribute if it matches.  Throw it away otherwise.
10795           // No attribute means no claim to conform.
10796           if (in_attr[i].string_value() != out_attr[i].string_value())
10797             out_attr[i].set_string_value("");
10798           break;
10799
10800         default:
10801           {
10802             const char* err_object = NULL;
10803
10804             // The "known_obj_attributes" table does contain some undefined
10805             // attributes.  Ensure that there are unused.
10806             if (out_attr[i].int_value() != 0
10807                 || out_attr[i].string_value() != "")
10808               err_object = "output";
10809             else if (in_attr[i].int_value() != 0
10810                      || in_attr[i].string_value() != "")
10811               err_object = name;
10812
10813             if (err_object != NULL
10814                 && parameters->options().warn_mismatch())
10815               {
10816                 // Attribute numbers >=64 (mod 128) can be safely ignored.
10817                 if ((i & 127) < 64)
10818                   gold_error(_("%s: unknown mandatory EABI object attribute "
10819                                "%d"),
10820                              err_object, i);
10821                 else
10822                   gold_warning(_("%s: unknown EABI object attribute %d"),
10823                                err_object, i);
10824               }
10825
10826             // Only pass on attributes that match in both inputs.
10827             if (!in_attr[i].matches(out_attr[i]))
10828               {
10829                 out_attr[i].set_int_value(0);
10830                 out_attr[i].set_string_value("");
10831               }
10832           }
10833         }
10834
10835       // If out_attr was copied from in_attr then it won't have a type yet.
10836       if (in_attr[i].type() && !out_attr[i].type())
10837         out_attr[i].set_type(in_attr[i].type());
10838     }
10839
10840   // Merge Tag_compatibility attributes and any common GNU ones.
10841   this->attributes_section_data_->merge(name, pasd);
10842
10843   // Check for any attributes not known on ARM.
10844   typedef Vendor_object_attributes::Other_attributes Other_attributes;
10845   const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10846   Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10847   Other_attributes* out_other_attributes =
10848     this->attributes_section_data_->other_attributes(vendor);
10849   Other_attributes::iterator out_iter = out_other_attributes->begin();
10850
10851   while (in_iter != in_other_attributes->end()
10852          || out_iter != out_other_attributes->end())
10853     {
10854       const char* err_object = NULL;
10855       int err_tag = 0;
10856
10857       // The tags for each list are in numerical order.
10858       // If the tags are equal, then merge.
10859       if (out_iter != out_other_attributes->end()
10860           && (in_iter == in_other_attributes->end()
10861               || in_iter->first > out_iter->first))
10862         {
10863           // This attribute only exists in output.  We can't merge, and we
10864           // don't know what the tag means, so delete it.
10865           err_object = "output";
10866           err_tag = out_iter->first;
10867           int saved_tag = out_iter->first;
10868           delete out_iter->second;
10869           out_other_attributes->erase(out_iter);
10870           out_iter = out_other_attributes->upper_bound(saved_tag);
10871         }
10872       else if (in_iter != in_other_attributes->end()
10873                && (out_iter != out_other_attributes->end()
10874                    || in_iter->first < out_iter->first))
10875         {
10876           // This attribute only exists in input. We can't merge, and we
10877           // don't know what the tag means, so ignore it.
10878           err_object = name;
10879           err_tag = in_iter->first;
10880           ++in_iter;
10881         }
10882       else // The tags are equal.
10883         {
10884           // As present, all attributes in the list are unknown, and
10885           // therefore can't be merged meaningfully.
10886           err_object = "output";
10887           err_tag = out_iter->first;
10888
10889           //  Only pass on attributes that match in both inputs.
10890           if (!in_iter->second->matches(*(out_iter->second)))
10891             {
10892               // No match.  Delete the attribute.
10893               int saved_tag = out_iter->first;
10894               delete out_iter->second;
10895               out_other_attributes->erase(out_iter);
10896               out_iter = out_other_attributes->upper_bound(saved_tag);
10897             }
10898           else
10899             {
10900               // Matched.  Keep the attribute and move to the next.
10901               ++out_iter;
10902               ++in_iter;
10903             }
10904         }
10905
10906       if (err_object && parameters->options().warn_mismatch())
10907         {
10908           // Attribute numbers >=64 (mod 128) can be safely ignored.  */
10909           if ((err_tag & 127) < 64)
10910             {
10911               gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10912                          err_object, err_tag);
10913             }
10914           else
10915             {
10916               gold_warning(_("%s: unknown EABI object attribute %d"),
10917                            err_object, err_tag);
10918             }
10919         }
10920     }
10921 }
10922
10923 // Stub-generation methods for Target_arm.
10924
10925 // Make a new Arm_input_section object.
10926
10927 template<bool big_endian>
10928 Arm_input_section<big_endian>*
10929 Target_arm<big_endian>::new_arm_input_section(
10930     Relobj* relobj,
10931     unsigned int shndx)
10932 {
10933   Section_id sid(relobj, shndx);
10934
10935   Arm_input_section<big_endian>* arm_input_section =
10936     new Arm_input_section<big_endian>(relobj, shndx);
10937   arm_input_section->init();
10938
10939   // Register new Arm_input_section in map for look-up.
10940   std::pair<typename Arm_input_section_map::iterator, bool> ins =
10941     this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
10942
10943   // Make sure that it we have not created another Arm_input_section
10944   // for this input section already.
10945   gold_assert(ins.second);
10946
10947   return arm_input_section;
10948 }
10949
10950 // Find the Arm_input_section object corresponding to the SHNDX-th input
10951 // section of RELOBJ.
10952
10953 template<bool big_endian>
10954 Arm_input_section<big_endian>*
10955 Target_arm<big_endian>::find_arm_input_section(
10956     Relobj* relobj,
10957     unsigned int shndx) const
10958 {
10959   Section_id sid(relobj, shndx);
10960   typename Arm_input_section_map::const_iterator p =
10961     this->arm_input_section_map_.find(sid);
10962   return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
10963 }
10964
10965 // Make a new stub table.
10966
10967 template<bool big_endian>
10968 Stub_table<big_endian>*
10969 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
10970 {
10971   Stub_table<big_endian>* stub_table =
10972     new Stub_table<big_endian>(owner);
10973   this->stub_tables_.push_back(stub_table);
10974
10975   stub_table->set_address(owner->address() + owner->data_size());
10976   stub_table->set_file_offset(owner->offset() + owner->data_size());
10977   stub_table->finalize_data_size();
10978
10979   return stub_table;
10980 }
10981
10982 // Scan a relocation for stub generation.
10983
10984 template<bool big_endian>
10985 void
10986 Target_arm<big_endian>::scan_reloc_for_stub(
10987     const Relocate_info<32, big_endian>* relinfo,
10988     unsigned int r_type,
10989     const Sized_symbol<32>* gsym,
10990     unsigned int r_sym,
10991     const Symbol_value<32>* psymval,
10992     elfcpp::Elf_types<32>::Elf_Swxword addend,
10993     Arm_address address)
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   gold::Default_comdat_behavior default_comdat_behavior;
11154   Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11155
11156   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11157     {
11158       Reltype reloc(prelocs);
11159
11160       typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11161       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11162       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11163
11164       r_type = this->get_real_reloc_type(r_type);
11165
11166       // Only a few relocation types need stubs.
11167       if ((r_type != elfcpp::R_ARM_CALL)
11168          && (r_type != elfcpp::R_ARM_JUMP24)
11169          && (r_type != elfcpp::R_ARM_PLT32)
11170          && (r_type != elfcpp::R_ARM_THM_CALL)
11171          && (r_type != elfcpp::R_ARM_THM_XPC22)
11172          && (r_type != elfcpp::R_ARM_THM_JUMP24)
11173          && (r_type != elfcpp::R_ARM_THM_JUMP19)
11174          && (r_type != elfcpp::R_ARM_V4BX))
11175         continue;
11176
11177       section_offset_type offset =
11178         convert_to_section_size_type(reloc.get_r_offset());
11179
11180       if (needs_special_offset_handling)
11181         {
11182           offset = output_section->output_offset(relinfo->object,
11183                                                  relinfo->data_shndx,
11184                                                  offset);
11185           if (offset == -1)
11186             continue;
11187         }
11188
11189       // Create a v4bx stub if --fix-v4bx-interworking is used.
11190       if (r_type == elfcpp::R_ARM_V4BX)
11191         {
11192           if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11193             {
11194               // Get the BX instruction.
11195               typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11196               const Valtype* wv =
11197                 reinterpret_cast<const Valtype*>(view + offset);
11198               elfcpp::Elf_types<32>::Elf_Swxword insn =
11199                 elfcpp::Swap<32, big_endian>::readval(wv);
11200               const uint32_t reg = (insn & 0xf);
11201
11202               if (reg < 0xf)
11203                 {
11204                   // Try looking up an existing stub from a stub table.
11205                   Stub_table<big_endian>* stub_table =
11206                     arm_object->stub_table(relinfo->data_shndx);
11207                   gold_assert(stub_table != NULL);
11208
11209                   if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11210                     {
11211                       // create a new stub and add it to stub table.
11212                       Arm_v4bx_stub* stub =
11213                         this->stub_factory().make_arm_v4bx_stub(reg);
11214                       gold_assert(stub != NULL);
11215                       stub_table->add_arm_v4bx_stub(stub);
11216                     }
11217                 }
11218             }
11219           continue;
11220         }
11221
11222       // Get the addend.
11223       Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11224       elfcpp::Elf_types<32>::Elf_Swxword addend =
11225         stub_addend_reader(r_type, view + offset, reloc);
11226
11227       const Sized_symbol<32>* sym;
11228
11229       Symbol_value<32> symval;
11230       const Symbol_value<32> *psymval;
11231       bool is_defined_in_discarded_section;
11232       unsigned int shndx;
11233       if (r_sym < local_count)
11234         {
11235           sym = NULL;
11236           psymval = arm_object->local_symbol(r_sym);
11237
11238           // If the local symbol belongs to a section we are discarding,
11239           // and that section is a debug section, try to find the
11240           // corresponding kept section and map this symbol to its
11241           // counterpart in the kept section.  The symbol must not
11242           // correspond to a section we are folding.
11243           bool is_ordinary;
11244           shndx = psymval->input_shndx(&is_ordinary);
11245           is_defined_in_discarded_section =
11246             (is_ordinary
11247              && shndx != elfcpp::SHN_UNDEF
11248              && !arm_object->is_section_included(shndx)
11249              && !relinfo->symtab->is_section_folded(arm_object, shndx));
11250
11251           // We need to compute the would-be final value of this local
11252           // symbol.
11253           if (!is_defined_in_discarded_section)
11254             {
11255               typedef Sized_relobj_file<32, big_endian> ObjType;
11256               typename ObjType::Compute_final_local_value_status status =
11257                 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11258                                                       relinfo->symtab);
11259               if (status == ObjType::CFLV_OK)
11260                 {
11261                   // Currently we cannot handle a branch to a target in
11262                   // a merged section.  If this is the case, issue an error
11263                   // and also free the merge symbol value.
11264                   if (!symval.has_output_value())
11265                     {
11266                       const std::string& section_name =
11267                         arm_object->section_name(shndx);
11268                       arm_object->error(_("cannot handle branch to local %u "
11269                                           "in a merged section %s"),
11270                                         r_sym, section_name.c_str());
11271                     }
11272                   psymval = &symval;
11273                 }
11274               else
11275                 {
11276                   // We cannot determine the final value.
11277                   continue;
11278                 }
11279             }
11280         }
11281       else
11282         {
11283           const Symbol* gsym;
11284           gsym = arm_object->global_symbol(r_sym);
11285           gold_assert(gsym != NULL);
11286           if (gsym->is_forwarder())
11287             gsym = relinfo->symtab->resolve_forwards(gsym);
11288
11289           sym = static_cast<const Sized_symbol<32>*>(gsym);
11290           if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11291             symval.set_output_symtab_index(sym->symtab_index());
11292           else
11293             symval.set_no_output_symtab_entry();
11294
11295           // We need to compute the would-be final value of this global
11296           // symbol.
11297           const Symbol_table* symtab = relinfo->symtab;
11298           const Sized_symbol<32>* sized_symbol =
11299             symtab->get_sized_symbol<32>(gsym);
11300           Symbol_table::Compute_final_value_status status;
11301           Arm_address value =
11302             symtab->compute_final_value<32>(sized_symbol, &status);
11303
11304           // Skip this if the symbol has not output section.
11305           if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11306             continue;
11307           symval.set_output_value(value);
11308
11309           if (gsym->type() == elfcpp::STT_TLS)
11310             symval.set_is_tls_symbol();
11311           else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11312             symval.set_is_ifunc_symbol();
11313           psymval = &symval;
11314
11315           is_defined_in_discarded_section =
11316             (gsym->is_defined_in_discarded_section()
11317              && gsym->is_undefined());
11318           shndx = 0;
11319         }
11320
11321       Symbol_value<32> symval2;
11322       if (is_defined_in_discarded_section)
11323         {
11324           if (comdat_behavior == CB_UNDETERMINED)
11325             {
11326               std::string name = arm_object->section_name(relinfo->data_shndx);
11327               comdat_behavior = default_comdat_behavior.get(name.c_str());
11328             }
11329           if (comdat_behavior == CB_PRETEND)
11330             {
11331               // FIXME: This case does not work for global symbols.
11332               // We have no place to store the original section index.
11333               // Fortunately this does not matter for comdat sections,
11334               // only for sections explicitly discarded by a linker
11335               // script.
11336               bool found;
11337               typename elfcpp::Elf_types<32>::Elf_Addr value =
11338                 arm_object->map_to_kept_section(shndx, &found);
11339               if (found)
11340                 symval2.set_output_value(value + psymval->input_value());
11341               else
11342                 symval2.set_output_value(0);
11343             }
11344           else
11345             {
11346               if (comdat_behavior == CB_WARNING)
11347                 gold_warning_at_location(relinfo, i, offset,
11348                                          _("relocation refers to discarded "
11349                                            "section"));
11350               symval2.set_output_value(0);
11351             }
11352           symval2.set_no_output_symtab_entry();
11353           psymval = &symval2;
11354         }
11355
11356       // If symbol is a section symbol, we don't know the actual type of
11357       // destination.  Give up.
11358       if (psymval->is_section_symbol())
11359         continue;
11360
11361       this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11362                                 addend, view_address + offset);
11363     }
11364 }
11365
11366 // Scan an input section for stub generation.
11367
11368 template<bool big_endian>
11369 void
11370 Target_arm<big_endian>::scan_section_for_stubs(
11371     const Relocate_info<32, big_endian>* relinfo,
11372     unsigned int sh_type,
11373     const unsigned char* prelocs,
11374     size_t reloc_count,
11375     Output_section* output_section,
11376     bool needs_special_offset_handling,
11377     const unsigned char* view,
11378     Arm_address view_address,
11379     section_size_type view_size)
11380 {
11381   if (sh_type == elfcpp::SHT_REL)
11382     this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11383         relinfo,
11384         prelocs,
11385         reloc_count,
11386         output_section,
11387         needs_special_offset_handling,
11388         view,
11389         view_address,
11390         view_size);
11391   else if (sh_type == elfcpp::SHT_RELA)
11392     // We do not support RELA type relocations yet.  This is provided for
11393     // completeness.
11394     this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11395         relinfo,
11396         prelocs,
11397         reloc_count,
11398         output_section,
11399         needs_special_offset_handling,
11400         view,
11401         view_address,
11402         view_size);
11403   else
11404     gold_unreachable();
11405 }
11406
11407 // Group input sections for stub generation.
11408 //
11409 // We group input sections in an output section so that the total size,
11410 // including any padding space due to alignment is smaller than GROUP_SIZE
11411 // unless the only input section in group is bigger than GROUP_SIZE already.
11412 // Then an ARM stub table is created to follow the last input section
11413 // in group.  For each group an ARM stub table is created an is placed
11414 // after the last group.  If STUB_ALWAYS_AFTER_BRANCH is false, we further
11415 // extend the group after the stub table.
11416
11417 template<bool big_endian>
11418 void
11419 Target_arm<big_endian>::group_sections(
11420     Layout* layout,
11421     section_size_type group_size,
11422     bool stubs_always_after_branch,
11423     const Task* task)
11424 {
11425   // Group input sections and insert stub table
11426   Layout::Section_list section_list;
11427   layout->get_allocated_sections(&section_list);
11428   for (Layout::Section_list::const_iterator p = section_list.begin();
11429        p != section_list.end();
11430        ++p)
11431     {
11432       Arm_output_section<big_endian>* output_section =
11433         Arm_output_section<big_endian>::as_arm_output_section(*p);
11434       output_section->group_sections(group_size, stubs_always_after_branch,
11435                                      this, task);
11436     }
11437 }
11438
11439 // Relaxation hook.  This is where we do stub generation.
11440
11441 template<bool big_endian>
11442 bool
11443 Target_arm<big_endian>::do_relax(
11444     int pass,
11445     const Input_objects* input_objects,
11446     Symbol_table* symtab,
11447     Layout* layout,
11448     const Task* task)
11449 {
11450   // No need to generate stubs if this is a relocatable link.
11451   gold_assert(!parameters->options().relocatable());
11452
11453   // If this is the first pass, we need to group input sections into
11454   // stub groups.
11455   bool done_exidx_fixup = false;
11456   typedef typename Stub_table_list::iterator Stub_table_iterator;
11457   if (pass == 1)
11458     {
11459       // Determine the stub group size.  The group size is the absolute
11460       // value of the parameter --stub-group-size.  If --stub-group-size
11461       // is passed a negative value, we restrict stubs to be always after
11462       // the stubbed branches.
11463       int32_t stub_group_size_param =
11464         parameters->options().stub_group_size();
11465       bool stubs_always_after_branch = stub_group_size_param < 0;
11466       section_size_type stub_group_size = abs(stub_group_size_param);
11467
11468       if (stub_group_size == 1)
11469         {
11470           // Default value.
11471           // Thumb branch range is +-4MB has to be used as the default
11472           // maximum size (a given section can contain both ARM and Thumb
11473           // code, so the worst case has to be taken into account).  If we are
11474           // fixing cortex-a8 errata, the branch range has to be even smaller,
11475           // since wide conditional branch has a range of +-1MB only.
11476           //
11477           // This value is 48K less than that, which allows for 4096
11478           // 12-byte stubs.  If we exceed that, then we will fail to link.
11479           // The user will have to relink with an explicit group size
11480           // option.
11481             stub_group_size = 4145152;
11482         }
11483
11484       // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11485       // page as the first half of a 32-bit branch straddling two 4K pages.
11486       // This is a crude way of enforcing that.  In addition, long conditional
11487       // branches of THUMB-2 have a range of +-1M.  If we are fixing cortex-A8
11488       // erratum, limit the group size to  (1M - 12k) to avoid unreachable
11489       // cortex-A8 stubs from long conditional branches.
11490       if (this->fix_cortex_a8_)
11491         {
11492           stubs_always_after_branch = true;
11493           const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11494           stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11495         }
11496
11497       group_sections(layout, stub_group_size, stubs_always_after_branch, task);
11498
11499       // Also fix .ARM.exidx section coverage.
11500       Arm_output_section<big_endian>* exidx_output_section = NULL;
11501       for (Layout::Section_list::const_iterator p =
11502              layout->section_list().begin();
11503            p != layout->section_list().end();
11504            ++p)
11505         if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11506           {
11507             if (exidx_output_section == NULL)
11508               exidx_output_section =
11509                 Arm_output_section<big_endian>::as_arm_output_section(*p);
11510             else
11511               // We cannot handle this now.
11512               gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11513                            "non-relocatable link"),
11514                           exidx_output_section->name(),
11515                           (*p)->name());
11516           }
11517
11518       if (exidx_output_section != NULL)
11519         {
11520           this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11521                                    symtab, task);
11522           done_exidx_fixup = true;
11523         }
11524     }
11525   else
11526     {
11527       // If this is not the first pass, addresses and file offsets have
11528       // been reset at this point, set them here.
11529       for (Stub_table_iterator sp = this->stub_tables_.begin();
11530            sp != this->stub_tables_.end();
11531            ++sp)
11532         {
11533           Arm_input_section<big_endian>* owner = (*sp)->owner();
11534           off_t off = align_address(owner->original_size(),
11535                                     (*sp)->addralign());
11536           (*sp)->set_address_and_file_offset(owner->address() + off,
11537                                              owner->offset() + off);
11538         }
11539     }
11540
11541   // The Cortex-A8 stubs are sensitive to layout of code sections.  At the
11542   // beginning of each relaxation pass, just blow away all the stubs.
11543   // Alternatively, we could selectively remove only the stubs and reloc
11544   // information for code sections that have moved since the last pass.
11545   // That would require more book-keeping.
11546   if (this->fix_cortex_a8_)
11547     {
11548       // Clear all Cortex-A8 reloc information.
11549       for (typename Cortex_a8_relocs_info::const_iterator p =
11550              this->cortex_a8_relocs_info_.begin();
11551            p != this->cortex_a8_relocs_info_.end();
11552            ++p)
11553         delete p->second;
11554       this->cortex_a8_relocs_info_.clear();
11555
11556       // Remove all Cortex-A8 stubs.
11557       for (Stub_table_iterator sp = this->stub_tables_.begin();
11558            sp != this->stub_tables_.end();
11559            ++sp)
11560         (*sp)->remove_all_cortex_a8_stubs();
11561     }
11562
11563   // Scan relocs for relocation stubs
11564   for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11565        op != input_objects->relobj_end();
11566        ++op)
11567     {
11568       Arm_relobj<big_endian>* arm_relobj =
11569         Arm_relobj<big_endian>::as_arm_relobj(*op);
11570       // Lock the object so we can read from it.  This is only called
11571       // single-threaded from Layout::finalize, so it is OK to lock.
11572       Task_lock_obj<Object> tl(task, arm_relobj);
11573       arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11574     }
11575
11576   // Check all stub tables to see if any of them have their data sizes
11577   // or addresses alignments changed.  These are the only things that
11578   // matter.
11579   bool any_stub_table_changed = false;
11580   Unordered_set<const Output_section*> sections_needing_adjustment;
11581   for (Stub_table_iterator sp = this->stub_tables_.begin();
11582        (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11583        ++sp)
11584     {
11585       if ((*sp)->update_data_size_and_addralign())
11586         {
11587           // Update data size of stub table owner.
11588           Arm_input_section<big_endian>* owner = (*sp)->owner();
11589           uint64_t address = owner->address();
11590           off_t offset = owner->offset();
11591           owner->reset_address_and_file_offset();
11592           owner->set_address_and_file_offset(address, offset);
11593
11594           sections_needing_adjustment.insert(owner->output_section());
11595           any_stub_table_changed = true;
11596         }
11597     }
11598
11599   // Output_section_data::output_section() returns a const pointer but we
11600   // need to update output sections, so we record all output sections needing
11601   // update above and scan the sections here to find out what sections need
11602   // to be updated.
11603   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
11604       p != layout->section_list().end();
11605       ++p)
11606     {
11607       if (sections_needing_adjustment.find(*p)
11608           != sections_needing_adjustment.end())
11609         (*p)->set_section_offsets_need_adjustment();
11610     }
11611
11612   // Stop relaxation if no EXIDX fix-up and no stub table change.
11613   bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11614
11615   // Finalize the stubs in the last relaxation pass.
11616   if (!continue_relaxation)
11617     {
11618       for (Stub_table_iterator sp = this->stub_tables_.begin();
11619            (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11620             ++sp)
11621         (*sp)->finalize_stubs();
11622
11623       // Update output local symbol counts of objects if necessary.
11624       for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11625            op != input_objects->relobj_end();
11626            ++op)
11627         {
11628           Arm_relobj<big_endian>* arm_relobj =
11629             Arm_relobj<big_endian>::as_arm_relobj(*op);
11630
11631           // Update output local symbol counts.  We need to discard local
11632           // symbols defined in parts of input sections that are discarded by
11633           // relaxation.
11634           if (arm_relobj->output_local_symbol_count_needs_update())
11635             {
11636               // We need to lock the object's file to update it.
11637               Task_lock_obj<Object> tl(task, arm_relobj);
11638               arm_relobj->update_output_local_symbol_count();
11639             }
11640         }
11641     }
11642
11643   return continue_relaxation;
11644 }
11645
11646 // Relocate a stub.
11647
11648 template<bool big_endian>
11649 void
11650 Target_arm<big_endian>::relocate_stub(
11651     Stub* stub,
11652     const Relocate_info<32, big_endian>* relinfo,
11653     Output_section* output_section,
11654     unsigned char* view,
11655     Arm_address address,
11656     section_size_type view_size)
11657 {
11658   Relocate relocate;
11659   const Stub_template* stub_template = stub->stub_template();
11660   for (size_t i = 0; i < stub_template->reloc_count(); i++)
11661     {
11662       size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11663       const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11664
11665       unsigned int r_type = insn->r_type();
11666       section_size_type reloc_offset = stub_template->reloc_offset(i);
11667       section_size_type reloc_size = insn->size();
11668       gold_assert(reloc_offset + reloc_size <= view_size);
11669
11670       // This is the address of the stub destination.
11671       Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11672       Symbol_value<32> symval;
11673       symval.set_output_value(target);
11674
11675       // Synthesize a fake reloc just in case.  We don't have a symbol so
11676       // we use 0.
11677       unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11678       memset(reloc_buffer, 0, sizeof(reloc_buffer));
11679       elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11680       reloc_write.put_r_offset(reloc_offset);
11681       reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11682       elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11683
11684       relocate.relocate(relinfo, this, output_section,
11685                         this->fake_relnum_for_stubs, rel, r_type,
11686                         NULL, &symval, view + reloc_offset,
11687                         address + reloc_offset, reloc_size);
11688     }
11689 }
11690
11691 // Determine whether an object attribute tag takes an integer, a
11692 // string or both.
11693
11694 template<bool big_endian>
11695 int
11696 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11697 {
11698   if (tag == Object_attribute::Tag_compatibility)
11699     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11700             | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11701   else if (tag == elfcpp::Tag_nodefaults)
11702     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11703             | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11704   else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11705     return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11706   else if (tag < 32)
11707     return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11708   else
11709     return ((tag & 1) != 0
11710             ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11711             : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11712 }
11713
11714 // Reorder attributes.
11715 //
11716 // The ABI defines that Tag_conformance should be emitted first, and that
11717 // Tag_nodefaults should be second (if either is defined).  This sets those
11718 // two positions, and bumps up the position of all the remaining tags to
11719 // compensate.
11720
11721 template<bool big_endian>
11722 int
11723 Target_arm<big_endian>::do_attributes_order(int num) const
11724 {
11725   // Reorder the known object attributes in output.  We want to move
11726   // Tag_conformance to position 4 and Tag_conformance to position 5
11727   // and shift everything between 4 .. Tag_conformance - 1 to make room.
11728   if (num == 4)
11729     return elfcpp::Tag_conformance;
11730   if (num == 5)
11731     return elfcpp::Tag_nodefaults;
11732   if ((num - 2) < elfcpp::Tag_nodefaults)
11733     return num - 2;
11734   if ((num - 1) < elfcpp::Tag_conformance)
11735     return num - 1;
11736   return num;
11737 }
11738
11739 // Scan a span of THUMB code for Cortex-A8 erratum.
11740
11741 template<bool big_endian>
11742 void
11743 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11744     Arm_relobj<big_endian>* arm_relobj,
11745     unsigned int shndx,
11746     section_size_type span_start,
11747     section_size_type span_end,
11748     const unsigned char* view,
11749     Arm_address address)
11750 {
11751   // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11752   //
11753   // The opcode is BLX.W, BL.W, B.W, Bcc.W
11754   // The branch target is in the same 4KB region as the
11755   // first half of the branch.
11756   // The instruction before the branch is a 32-bit
11757   // length non-branch instruction.
11758   section_size_type i = span_start;
11759   bool last_was_32bit = false;
11760   bool last_was_branch = false;
11761   while (i < span_end)
11762     {
11763       typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11764       const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11765       uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11766       bool is_blx = false, is_b = false;
11767       bool is_bl = false, is_bcc = false;
11768
11769       bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11770       if (insn_32bit)
11771         {
11772           // Load the rest of the insn (in manual-friendly order).
11773           insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11774
11775           // Encoding T4: B<c>.W.
11776           is_b = (insn & 0xf800d000U) == 0xf0009000U;
11777           // Encoding T1: BL<c>.W.
11778           is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11779           // Encoding T2: BLX<c>.W.
11780           is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11781           // Encoding T3: B<c>.W (not permitted in IT block).
11782           is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11783                     && (insn & 0x07f00000U) != 0x03800000U);
11784         }
11785
11786       bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11787
11788       // If this instruction is a 32-bit THUMB branch that crosses a 4K
11789       // page boundary and it follows 32-bit non-branch instruction,
11790       // we need to work around.
11791       if (is_32bit_branch
11792           && ((address + i) & 0xfffU) == 0xffeU
11793           && last_was_32bit
11794           && !last_was_branch)
11795         {
11796           // Check to see if there is a relocation stub for this branch.
11797           bool force_target_arm = false;
11798           bool force_target_thumb = false;
11799           const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11800           Cortex_a8_relocs_info::const_iterator p =
11801             this->cortex_a8_relocs_info_.find(address + i);
11802
11803           if (p != this->cortex_a8_relocs_info_.end())
11804             {
11805               cortex_a8_reloc = p->second;
11806               bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11807
11808               if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11809                   && !target_is_thumb)
11810                 force_target_arm = true;
11811               else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11812                        && target_is_thumb)
11813                 force_target_thumb = true;
11814             }
11815
11816           off_t offset;
11817           Stub_type stub_type = arm_stub_none;
11818
11819           // Check if we have an offending branch instruction.
11820           uint16_t upper_insn = (insn >> 16) & 0xffffU;
11821           uint16_t lower_insn = insn & 0xffffU;
11822           typedef class Arm_relocate_functions<big_endian> RelocFuncs;
11823
11824           if (cortex_a8_reloc != NULL
11825               && cortex_a8_reloc->reloc_stub() != NULL)
11826             // We've already made a stub for this instruction, e.g.
11827             // it's a long branch or a Thumb->ARM stub.  Assume that
11828             // stub will suffice to work around the A8 erratum (see
11829             // setting of always_after_branch above).
11830             ;
11831           else if (is_bcc)
11832             {
11833               offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11834                                                               lower_insn);
11835               stub_type = arm_stub_a8_veneer_b_cond;
11836             }
11837           else if (is_b || is_bl || is_blx)
11838             {
11839               offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11840                                                          lower_insn);
11841               if (is_blx)
11842                 offset &= ~3;
11843
11844               stub_type = (is_blx
11845                            ? arm_stub_a8_veneer_blx
11846                            : (is_bl
11847                               ? arm_stub_a8_veneer_bl
11848                               : arm_stub_a8_veneer_b));
11849             }
11850
11851           if (stub_type != arm_stub_none)
11852             {
11853               Arm_address pc_for_insn = address + i + 4;
11854
11855               // The original instruction is a BL, but the target is
11856               // an ARM instruction.  If we were not making a stub,
11857               // the BL would have been converted to a BLX.  Use the
11858               // BLX stub instead in that case.
11859               if (this->may_use_v5t_interworking() && force_target_arm
11860                   && stub_type == arm_stub_a8_veneer_bl)
11861                 {
11862                   stub_type = arm_stub_a8_veneer_blx;
11863                   is_blx = true;
11864                   is_bl = false;
11865                 }
11866               // Conversely, if the original instruction was
11867               // BLX but the target is Thumb mode, use the BL stub.
11868               else if (force_target_thumb
11869                        && stub_type == arm_stub_a8_veneer_blx)
11870                 {
11871                   stub_type = arm_stub_a8_veneer_bl;
11872                   is_blx = false;
11873                   is_bl = true;
11874                 }
11875
11876               if (is_blx)
11877                 pc_for_insn &= ~3;
11878
11879               // If we found a relocation, use the proper destination,
11880               // not the offset in the (unrelocated) instruction.
11881               // Note this is always done if we switched the stub type above.
11882               if (cortex_a8_reloc != NULL)
11883                 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11884
11885               Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11886
11887               // Add a new stub if destination address in in the same page.
11888               if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11889                 {
11890                   Cortex_a8_stub* stub =
11891                     this->stub_factory_.make_cortex_a8_stub(stub_type,
11892                                                             arm_relobj, shndx,
11893                                                             address + i,
11894                                                             target, insn);
11895                   Stub_table<big_endian>* stub_table =
11896                     arm_relobj->stub_table(shndx);
11897                   gold_assert(stub_table != NULL);
11898                   stub_table->add_cortex_a8_stub(address + i, stub);
11899                 }
11900             }
11901         }
11902
11903       i += insn_32bit ? 4 : 2;
11904       last_was_32bit = insn_32bit;
11905       last_was_branch = is_32bit_branch;
11906     }
11907 }
11908
11909 // Apply the Cortex-A8 workaround.
11910
11911 template<bool big_endian>
11912 void
11913 Target_arm<big_endian>::apply_cortex_a8_workaround(
11914     const Cortex_a8_stub* stub,
11915     Arm_address stub_address,
11916     unsigned char* insn_view,
11917     Arm_address insn_address)
11918 {
11919   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11920   Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
11921   Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
11922   Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
11923   off_t branch_offset = stub_address - (insn_address + 4);
11924
11925   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
11926   switch (stub->stub_template()->type())
11927     {
11928     case arm_stub_a8_veneer_b_cond:
11929       // For a conditional branch, we re-write it to be an unconditional
11930       // branch to the stub.  We use the THUMB-2 encoding here.
11931       upper_insn = 0xf000U;
11932       lower_insn = 0xb800U;
11933       // Fall through
11934     case arm_stub_a8_veneer_b:
11935     case arm_stub_a8_veneer_bl:
11936     case arm_stub_a8_veneer_blx:
11937       if ((lower_insn & 0x5000U) == 0x4000U)
11938         // For a BLX instruction, make sure that the relocation is
11939         // rounded up to a word boundary.  This follows the semantics of
11940         // the instruction which specifies that bit 1 of the target
11941         // address will come from bit 1 of the base address.
11942         branch_offset = (branch_offset + 2) & ~3;
11943
11944       // Put BRANCH_OFFSET back into the insn.
11945       gold_assert(!Bits<25>::has_overflow32(branch_offset));
11946       upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
11947       lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
11948       break;
11949
11950     default:
11951       gold_unreachable();
11952     }
11953
11954   // Put the relocated value back in the object file:
11955   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
11956   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
11957 }
11958
11959 // Target selector for ARM.  Note this is never instantiated directly.
11960 // It's only used in Target_selector_arm_nacl, below.
11961
11962 template<bool big_endian>
11963 class Target_selector_arm : public Target_selector
11964 {
11965  public:
11966   Target_selector_arm()
11967     : Target_selector(elfcpp::EM_ARM, 32, big_endian,
11968                       (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
11969                       (big_endian ? "armelfb" : "armelf"))
11970   { }
11971
11972   Target*
11973   do_instantiate_target()
11974   { return new Target_arm<big_endian>(); }
11975 };
11976
11977 // Fix .ARM.exidx section coverage.
11978
11979 template<bool big_endian>
11980 void
11981 Target_arm<big_endian>::fix_exidx_coverage(
11982     Layout* layout,
11983     const Input_objects* input_objects,
11984     Arm_output_section<big_endian>* exidx_section,
11985     Symbol_table* symtab,
11986     const Task* task)
11987 {
11988   // We need to look at all the input sections in output in ascending
11989   // order of of output address.  We do that by building a sorted list
11990   // of output sections by addresses.  Then we looks at the output sections
11991   // in order.  The input sections in an output section are already sorted
11992   // by addresses within the output section.
11993
11994   typedef std::set<Output_section*, output_section_address_less_than>
11995       Sorted_output_section_list;
11996   Sorted_output_section_list sorted_output_sections;
11997
11998   // Find out all the output sections of input sections pointed by
11999   // EXIDX input sections.
12000   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
12001        p != input_objects->relobj_end();
12002        ++p)
12003     {
12004       Arm_relobj<big_endian>* arm_relobj =
12005         Arm_relobj<big_endian>::as_arm_relobj(*p);
12006       std::vector<unsigned int> shndx_list;
12007       arm_relobj->get_exidx_shndx_list(&shndx_list);
12008       for (size_t i = 0; i < shndx_list.size(); ++i)
12009         {
12010           const Arm_exidx_input_section* exidx_input_section =
12011             arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
12012           gold_assert(exidx_input_section != NULL);
12013           if (!exidx_input_section->has_errors())
12014             {
12015               unsigned int text_shndx = exidx_input_section->link();
12016               Output_section* os = arm_relobj->output_section(text_shndx);
12017               if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
12018                 sorted_output_sections.insert(os);
12019             }
12020         }
12021     }
12022
12023   // Go over the output sections in ascending order of output addresses.
12024   typedef typename Arm_output_section<big_endian>::Text_section_list
12025       Text_section_list;
12026   Text_section_list sorted_text_sections;
12027   for (typename Sorted_output_section_list::iterator p =
12028         sorted_output_sections.begin();
12029       p != sorted_output_sections.end();
12030       ++p)
12031     {
12032       Arm_output_section<big_endian>* arm_output_section =
12033         Arm_output_section<big_endian>::as_arm_output_section(*p);
12034       arm_output_section->append_text_sections_to_list(&sorted_text_sections);
12035     }
12036
12037   exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
12038                                     merge_exidx_entries(), task);
12039 }
12040
12041 template<bool big_endian>
12042 void
12043 Target_arm<big_endian>::do_define_standard_symbols(
12044     Symbol_table* symtab,
12045     Layout* layout)
12046 {
12047   // Handle the .ARM.exidx section.
12048   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
12049
12050   if (exidx_section != NULL)
12051     {
12052       // Create __exidx_start and __exidx_end symbols.
12053       symtab->define_in_output_data("__exidx_start",
12054                                     NULL, // version
12055                                     Symbol_table::PREDEFINED,
12056                                     exidx_section,
12057                                     0, // value
12058                                     0, // symsize
12059                                     elfcpp::STT_NOTYPE,
12060                                     elfcpp::STB_GLOBAL,
12061                                     elfcpp::STV_HIDDEN,
12062                                     0, // nonvis
12063                                     false, // offset_is_from_end
12064                                     true); // only_if_ref
12065
12066       symtab->define_in_output_data("__exidx_end",
12067                                     NULL, // version
12068                                     Symbol_table::PREDEFINED,
12069                                     exidx_section,
12070                                     0, // value
12071                                     0, // symsize
12072                                     elfcpp::STT_NOTYPE,
12073                                     elfcpp::STB_GLOBAL,
12074                                     elfcpp::STV_HIDDEN,
12075                                     0, // nonvis
12076                                     true, // offset_is_from_end
12077                                     true); // only_if_ref
12078     }
12079   else
12080     {
12081       // Define __exidx_start and __exidx_end even when .ARM.exidx
12082       // section is missing to match ld's behaviour.
12083       symtab->define_as_constant("__exidx_start", NULL,
12084                                  Symbol_table::PREDEFINED,
12085                                  0, 0, elfcpp::STT_OBJECT,
12086                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12087                                  true, false);
12088       symtab->define_as_constant("__exidx_end", NULL,
12089                                  Symbol_table::PREDEFINED,
12090                                  0, 0, elfcpp::STT_OBJECT,
12091                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12092                                  true, false);
12093     }
12094 }
12095
12096 // NaCl variant.  It uses different PLT contents.
12097
12098 template<bool big_endian>
12099 class Output_data_plt_arm_nacl;
12100
12101 template<bool big_endian>
12102 class Target_arm_nacl : public Target_arm<big_endian>
12103 {
12104  public:
12105   Target_arm_nacl()
12106     : Target_arm<big_endian>(&arm_nacl_info)
12107   { }
12108
12109  protected:
12110   virtual Output_data_plt_arm<big_endian>*
12111   do_make_data_plt(Layout* layout, Output_data_space* got_plt)
12112   { return new Output_data_plt_arm_nacl<big_endian>(layout, got_plt); }
12113
12114  private:
12115   static const Target::Target_info arm_nacl_info;
12116 };
12117
12118 template<bool big_endian>
12119 const Target::Target_info Target_arm_nacl<big_endian>::arm_nacl_info =
12120 {
12121   32,                   // size
12122   big_endian,           // is_big_endian
12123   elfcpp::EM_ARM,       // machine_code
12124   false,                // has_make_symbol
12125   false,                // has_resolve
12126   false,                // has_code_fill
12127   true,                 // is_default_stack_executable
12128   false,                // can_icf_inline_merge_sections
12129   '\0',                 // wrap_char
12130   "/lib/ld-nacl-arm.so.1", // dynamic_linker
12131   0x20000,              // default_text_segment_address
12132   0x10000,              // abi_pagesize (overridable by -z max-page-size)
12133   0x10000,              // common_pagesize (overridable by -z common-page-size)
12134   true,                 // isolate_execinstr
12135   0x10000000,           // rosegment_gap
12136   elfcpp::SHN_UNDEF,    // small_common_shndx
12137   elfcpp::SHN_UNDEF,    // large_common_shndx
12138   0,                    // small_common_section_flags
12139   0,                    // large_common_section_flags
12140   ".ARM.attributes",    // attributes_section
12141   "aeabi"               // attributes_vendor
12142 };
12143
12144 template<bool big_endian>
12145 class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
12146 {
12147  public:
12148   Output_data_plt_arm_nacl(Layout* layout, Output_data_space* got_plt)
12149     : Output_data_plt_arm<big_endian>(layout, 16, got_plt)
12150   { }
12151
12152  protected:
12153   // Return the offset of the first non-reserved PLT entry.
12154   virtual unsigned int
12155   do_first_plt_entry_offset() const
12156   { return sizeof(first_plt_entry); }
12157
12158   // Return the size of a PLT entry.
12159   virtual unsigned int
12160   do_get_plt_entry_size() const
12161   { return sizeof(plt_entry); }
12162
12163   virtual void
12164   do_fill_first_plt_entry(unsigned char* pov,
12165                           Arm_address got_address,
12166                           Arm_address plt_address);
12167
12168   virtual void
12169   do_fill_plt_entry(unsigned char* pov,
12170                     Arm_address got_address,
12171                     Arm_address plt_address,
12172                     unsigned int got_offset,
12173                     unsigned int plt_offset);
12174
12175  private:
12176   inline uint32_t arm_movw_immediate(uint32_t value)
12177   {
12178     return (value & 0x00000fff) | ((value & 0x0000f000) << 4);
12179   }
12180
12181   inline uint32_t arm_movt_immediate(uint32_t value)
12182   {
12183     return ((value & 0x0fff0000) >> 16) | ((value & 0xf0000000) >> 12);
12184   }
12185
12186   // Template for the first PLT entry.
12187   static const uint32_t first_plt_entry[16];
12188
12189   // Template for subsequent PLT entries.
12190   static const uint32_t plt_entry[4];
12191 };
12192
12193 // The first entry in the PLT.
12194 template<bool big_endian>
12195 const uint32_t Output_data_plt_arm_nacl<big_endian>::first_plt_entry[16] =
12196 {
12197   // First bundle:
12198   0xe300c000,                           // movw ip, #:lower16:&GOT[2]-.+8
12199   0xe340c000,                           // movt ip, #:upper16:&GOT[2]-.+8
12200   0xe08cc00f,                           // add  ip, ip, pc
12201   0xe52dc008,                           // str  ip, [sp, #-8]!
12202   // Second bundle:
12203   0xe7dfcf1f,                           // bfc  ip, #30, #2
12204   0xe59cc000,                           // ldr  ip, [ip]
12205   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
12206   0xe12fff1c,                           // bx   ip
12207   // Third bundle:
12208   0xe320f000,                           // nop
12209   0xe320f000,                           // nop
12210   0xe320f000,                           // nop
12211   // .Lplt_tail:
12212   0xe50dc004,                           // str  ip, [sp, #-4]
12213   // Fourth bundle:
12214   0xe7dfcf1f,                           // bfc  ip, #30, #2
12215   0xe59cc000,                           // ldr  ip, [ip]
12216   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
12217   0xe12fff1c,                           // bx   ip
12218 };
12219
12220 template<bool big_endian>
12221 void
12222 Output_data_plt_arm_nacl<big_endian>::do_fill_first_plt_entry(
12223     unsigned char* pov,
12224     Arm_address got_address,
12225     Arm_address plt_address)
12226 {
12227   // Write first PLT entry.  All but first two words are constants.
12228   const size_t num_first_plt_words = (sizeof(first_plt_entry)
12229                                       / sizeof(first_plt_entry[0]));
12230
12231   int32_t got_displacement = got_address + 8 - (plt_address + 16);
12232
12233   elfcpp::Swap<32, big_endian>::writeval
12234     (pov + 0, first_plt_entry[0] | arm_movw_immediate (got_displacement));
12235   elfcpp::Swap<32, big_endian>::writeval
12236     (pov + 4, first_plt_entry[1] | arm_movt_immediate (got_displacement));
12237
12238   for (size_t i = 2; i < num_first_plt_words; ++i)
12239     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
12240 }
12241
12242 // Subsequent entries in the PLT.
12243
12244 template<bool big_endian>
12245 const uint32_t Output_data_plt_arm_nacl<big_endian>::plt_entry[4] =
12246 {
12247   0xe300c000,                           // movw ip, #:lower16:&GOT[n]-.+8
12248   0xe340c000,                           // movt ip, #:upper16:&GOT[n]-.+8
12249   0xe08cc00f,                           // add  ip, ip, pc
12250   0xea000000,                           // b    .Lplt_tail
12251 };
12252
12253 template<bool big_endian>
12254 void
12255 Output_data_plt_arm_nacl<big_endian>::do_fill_plt_entry(
12256     unsigned char* pov,
12257     Arm_address got_address,
12258     Arm_address plt_address,
12259     unsigned int got_offset,
12260     unsigned int plt_offset)
12261 {
12262   // Calculate the displacement between the PLT slot and the
12263   // common tail that's part of the special initial PLT slot.
12264   int32_t tail_displacement = (plt_address + (11 * sizeof(uint32_t))
12265                                - (plt_address + plt_offset
12266                                   + sizeof(plt_entry) + sizeof(uint32_t)));
12267   gold_assert((tail_displacement & 3) == 0);
12268   tail_displacement >>= 2;
12269
12270   gold_assert ((tail_displacement & 0xff000000) == 0
12271                || (-tail_displacement & 0xff000000) == 0);
12272
12273   // Calculate the displacement between the PLT slot and the entry
12274   // in the GOT.  The offset accounts for the value produced by
12275   // adding to pc in the penultimate instruction of the PLT stub.
12276   const int32_t got_displacement = (got_address + got_offset
12277                                     - (plt_address + sizeof(plt_entry)));
12278
12279   elfcpp::Swap<32, big_endian>::writeval
12280     (pov + 0, plt_entry[0] | arm_movw_immediate (got_displacement));
12281   elfcpp::Swap<32, big_endian>::writeval
12282     (pov + 4, plt_entry[1] | arm_movt_immediate (got_displacement));
12283   elfcpp::Swap<32, big_endian>::writeval
12284     (pov + 8, plt_entry[2]);
12285   elfcpp::Swap<32, big_endian>::writeval
12286     (pov + 12, plt_entry[3] | (tail_displacement & 0x00ffffff));
12287 }
12288
12289 // Target selectors.
12290
12291 template<bool big_endian>
12292 class Target_selector_arm_nacl
12293   : public Target_selector_nacl<Target_selector_arm<big_endian>,
12294                                 Target_arm_nacl<big_endian> >
12295 {
12296  public:
12297   Target_selector_arm_nacl()
12298     : Target_selector_nacl<Target_selector_arm<big_endian>,
12299                            Target_arm_nacl<big_endian> >(
12300           "arm",
12301           big_endian ? "elf32-bigarm-nacl" : "elf32-littlearm-nacl",
12302           big_endian ? "armelfb_nacl" : "armelf_nacl")
12303   { }
12304 };
12305
12306 Target_selector_arm_nacl<false> target_selector_arm;
12307 Target_selector_arm_nacl<true> target_selector_armbe;
12308
12309 } // End anonymous namespace.