* output.h (Output_data_got::add_global_tls, add_local_tls,
[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
2556     inline void
2557     global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2558            Sized_relobj_file<32, big_endian>* object,
2559            unsigned int data_shndx,
2560            Output_section* output_section,
2561            const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2562            Symbol* gsym);
2563
2564     inline bool
2565     local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2566                                         Sized_relobj_file<32, big_endian>* ,
2567                                         unsigned int ,
2568                                         Output_section* ,
2569                                         const elfcpp::Rel<32, big_endian>& ,
2570                                         unsigned int ,
2571                                         const elfcpp::Sym<32, big_endian>&);
2572
2573     inline bool
2574     global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2575                                          Sized_relobj_file<32, big_endian>* ,
2576                                          unsigned int ,
2577                                          Output_section* ,
2578                                          const elfcpp::Rel<32, big_endian>& ,
2579                                          unsigned int , Symbol*);
2580
2581    private:
2582     static void
2583     unsupported_reloc_local(Sized_relobj_file<32, big_endian>*,
2584                             unsigned int r_type);
2585
2586     static void
2587     unsupported_reloc_global(Sized_relobj_file<32, big_endian>*,
2588                              unsigned int r_type, Symbol*);
2589
2590     void
2591     check_non_pic(Relobj*, unsigned int r_type);
2592
2593     // Almost identical to Symbol::needs_plt_entry except that it also
2594     // handles STT_ARM_TFUNC.
2595     static bool
2596     symbol_needs_plt_entry(const Symbol* sym)
2597     {
2598       // An undefined symbol from an executable does not need a PLT entry.
2599       if (sym->is_undefined() && !parameters->options().shared())
2600         return false;
2601
2602       return (!parameters->doing_static_link()
2603               && (sym->type() == elfcpp::STT_FUNC
2604                   || sym->type() == elfcpp::STT_ARM_TFUNC)
2605               && (sym->is_from_dynobj()
2606                   || sym->is_undefined()
2607                   || sym->is_preemptible()));
2608     }
2609
2610     inline bool
2611     possible_function_pointer_reloc(unsigned int r_type);
2612
2613     // Whether we have issued an error about a non-PIC compilation.
2614     bool issued_non_pic_error_;
2615   };
2616
2617   // The class which implements relocation.
2618   class Relocate
2619   {
2620    public:
2621     Relocate()
2622     { }
2623
2624     ~Relocate()
2625     { }
2626
2627     // Return whether the static relocation needs to be applied.
2628     inline bool
2629     should_apply_static_reloc(const Sized_symbol<32>* gsym,
2630                               unsigned int r_type,
2631                               bool is_32bit,
2632                               Output_section* output_section);
2633
2634     // Do a relocation.  Return false if the caller should not issue
2635     // any warnings about this relocation.
2636     inline bool
2637     relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2638              Output_section*,  size_t relnum,
2639              const elfcpp::Rel<32, big_endian>&,
2640              unsigned int r_type, const Sized_symbol<32>*,
2641              const Symbol_value<32>*,
2642              unsigned char*, Arm_address,
2643              section_size_type);
2644
2645     // Return whether we want to pass flag NON_PIC_REF for this
2646     // reloc.  This means the relocation type accesses a symbol not via
2647     // GOT or PLT.
2648     static inline bool
2649     reloc_is_non_pic(unsigned int r_type)
2650     {
2651       switch (r_type)
2652         {
2653         // These relocation types reference GOT or PLT entries explicitly.
2654         case elfcpp::R_ARM_GOT_BREL:
2655         case elfcpp::R_ARM_GOT_ABS:
2656         case elfcpp::R_ARM_GOT_PREL:
2657         case elfcpp::R_ARM_GOT_BREL12:
2658         case elfcpp::R_ARM_PLT32_ABS:
2659         case elfcpp::R_ARM_TLS_GD32:
2660         case elfcpp::R_ARM_TLS_LDM32:
2661         case elfcpp::R_ARM_TLS_IE32:
2662         case elfcpp::R_ARM_TLS_IE12GP:
2663
2664         // These relocate types may use PLT entries.
2665         case elfcpp::R_ARM_CALL:
2666         case elfcpp::R_ARM_THM_CALL:
2667         case elfcpp::R_ARM_JUMP24:
2668         case elfcpp::R_ARM_THM_JUMP24:
2669         case elfcpp::R_ARM_THM_JUMP19:
2670         case elfcpp::R_ARM_PLT32:
2671         case elfcpp::R_ARM_THM_XPC22:
2672         case elfcpp::R_ARM_PREL31:
2673         case elfcpp::R_ARM_SBREL31:
2674           return false;
2675
2676         default:
2677           return true;
2678         }
2679     }
2680
2681    private:
2682     // Do a TLS relocation.
2683     inline typename Arm_relocate_functions<big_endian>::Status
2684     relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2685                  size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2686                  const Sized_symbol<32>*, const Symbol_value<32>*,
2687                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2688                  section_size_type);
2689
2690   };
2691
2692   // A class which returns the size required for a relocation type,
2693   // used while scanning relocs during a relocatable link.
2694   class Relocatable_size_for_reloc
2695   {
2696    public:
2697     unsigned int
2698     get_size_for_reloc(unsigned int, Relobj*);
2699   };
2700
2701   // Adjust TLS relocation type based on the options and whether this
2702   // is a local symbol.
2703   static tls::Tls_optimization
2704   optimize_tls_reloc(bool is_final, int r_type);
2705
2706   // Get the GOT section, creating it if necessary.
2707   Arm_output_data_got<big_endian>*
2708   got_section(Symbol_table*, Layout*);
2709
2710   // Get the GOT PLT section.
2711   Output_data_space*
2712   got_plt_section() const
2713   {
2714     gold_assert(this->got_plt_ != NULL);
2715     return this->got_plt_;
2716   }
2717
2718   // Create a PLT entry for a global symbol.
2719   void
2720   make_plt_entry(Symbol_table*, Layout*, Symbol*);
2721
2722   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2723   void
2724   define_tls_base_symbol(Symbol_table*, Layout*);
2725
2726   // Create a GOT entry for the TLS module index.
2727   unsigned int
2728   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2729                       Sized_relobj_file<32, big_endian>* object);
2730
2731   // Get the PLT section.
2732   const Output_data_plt_arm<big_endian>*
2733   plt_section() const
2734   {
2735     gold_assert(this->plt_ != NULL);
2736     return this->plt_;
2737   }
2738
2739   // Get the dynamic reloc section, creating it if necessary.
2740   Reloc_section*
2741   rel_dyn_section(Layout*);
2742
2743   // Get the section to use for TLS_DESC relocations.
2744   Reloc_section*
2745   rel_tls_desc_section(Layout*) const;
2746
2747   // Return true if the symbol may need a COPY relocation.
2748   // References from an executable object to non-function symbols
2749   // defined in a dynamic object may need a COPY relocation.
2750   bool
2751   may_need_copy_reloc(Symbol* gsym)
2752   {
2753     return (gsym->type() != elfcpp::STT_ARM_TFUNC
2754             && gsym->may_need_copy_reloc());
2755   }
2756
2757   // Add a potential copy relocation.
2758   void
2759   copy_reloc(Symbol_table* symtab, Layout* layout,
2760              Sized_relobj_file<32, big_endian>* object,
2761              unsigned int shndx, Output_section* output_section,
2762              Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2763   {
2764     this->copy_relocs_.copy_reloc(symtab, layout,
2765                                   symtab->get_sized_symbol<32>(sym),
2766                                   object, shndx, output_section, reloc,
2767                                   this->rel_dyn_section(layout));
2768   }
2769
2770   // Whether two EABI versions are compatible.
2771   static bool
2772   are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2773
2774   // Merge processor-specific flags from input object and those in the ELF
2775   // header of the output.
2776   void
2777   merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2778
2779   // Get the secondary compatible architecture.
2780   static int
2781   get_secondary_compatible_arch(const Attributes_section_data*);
2782
2783   // Set the secondary compatible architecture.
2784   static void
2785   set_secondary_compatible_arch(Attributes_section_data*, int);
2786
2787   static int
2788   tag_cpu_arch_combine(const char*, int, int*, int, int);
2789
2790   // Helper to print AEABI enum tag value.
2791   static std::string
2792   aeabi_enum_name(unsigned int);
2793
2794   // Return string value for TAG_CPU_name.
2795   static std::string
2796   tag_cpu_name_value(unsigned int);
2797
2798   // Merge object attributes from input object and those in the output.
2799   void
2800   merge_object_attributes(const char*, const Attributes_section_data*);
2801
2802   // Helper to get an AEABI object attribute
2803   Object_attribute*
2804   get_aeabi_object_attribute(int tag) const
2805   {
2806     Attributes_section_data* pasd = this->attributes_section_data_;
2807     gold_assert(pasd != NULL);
2808     Object_attribute* attr =
2809       pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2810     gold_assert(attr != NULL);
2811     return attr;
2812   }
2813
2814   //
2815   // Methods to support stub-generations.
2816   //
2817
2818   // Group input sections for stub generation.
2819   void
2820   group_sections(Layout*, section_size_type, bool, const Task*);
2821
2822   // Scan a relocation for stub generation.
2823   void
2824   scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2825                       const Sized_symbol<32>*, unsigned int,
2826                       const Symbol_value<32>*,
2827                       elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2828
2829   // Scan a relocation section for stub.
2830   template<int sh_type>
2831   void
2832   scan_reloc_section_for_stubs(
2833       const Relocate_info<32, big_endian>* relinfo,
2834       const unsigned char* prelocs,
2835       size_t reloc_count,
2836       Output_section* output_section,
2837       bool needs_special_offset_handling,
2838       const unsigned char* view,
2839       elfcpp::Elf_types<32>::Elf_Addr view_address,
2840       section_size_type);
2841
2842   // Fix .ARM.exidx section coverage.
2843   void
2844   fix_exidx_coverage(Layout*, const Input_objects*,
2845                      Arm_output_section<big_endian>*, Symbol_table*,
2846                      const Task*);
2847
2848   // Functors for STL set.
2849   struct output_section_address_less_than
2850   {
2851     bool
2852     operator()(const Output_section* s1, const Output_section* s2) const
2853     { return s1->address() < s2->address(); }
2854   };
2855
2856   // Information about this specific target which we pass to the
2857   // general Target structure.
2858   static const Target::Target_info arm_info;
2859
2860   // The types of GOT entries needed for this platform.
2861   // These values are exposed to the ABI in an incremental link.
2862   // Do not renumber existing values without changing the version
2863   // number of the .gnu_incremental_inputs section.
2864   enum Got_type
2865   {
2866     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
2867     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
2868     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
2869     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
2870     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
2871   };
2872
2873   typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2874
2875   // Map input section to Arm_input_section.
2876   typedef Unordered_map<Section_id,
2877                         Arm_input_section<big_endian>*,
2878                         Section_id_hash>
2879           Arm_input_section_map;
2880
2881   // Map output addresses to relocs for Cortex-A8 erratum.
2882   typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2883           Cortex_a8_relocs_info;
2884
2885   // The GOT section.
2886   Arm_output_data_got<big_endian>* got_;
2887   // The PLT section.
2888   Output_data_plt_arm<big_endian>* plt_;
2889   // The GOT PLT section.
2890   Output_data_space* got_plt_;
2891   // The dynamic reloc section.
2892   Reloc_section* rel_dyn_;
2893   // Relocs saved to avoid a COPY reloc.
2894   Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2895   // Space for variables copied with a COPY reloc.
2896   Output_data_space* dynbss_;
2897   // Offset of the GOT entry for the TLS module index.
2898   unsigned int got_mod_index_offset_;
2899   // True if the _TLS_MODULE_BASE_ symbol has been defined.
2900   bool tls_base_symbol_defined_;
2901   // Vector of Stub_tables created.
2902   Stub_table_list stub_tables_;
2903   // Stub factory.
2904   const Stub_factory &stub_factory_;
2905   // Whether we force PIC branch veneers.
2906   bool should_force_pic_veneer_;
2907   // Map for locating Arm_input_sections.
2908   Arm_input_section_map arm_input_section_map_;
2909   // Attributes section data in output.
2910   Attributes_section_data* attributes_section_data_;
2911   // Whether we want to fix code for Cortex-A8 erratum.
2912   bool fix_cortex_a8_;
2913   // Map addresses to relocs for Cortex-A8 erratum.
2914   Cortex_a8_relocs_info cortex_a8_relocs_info_;
2915 };
2916
2917 template<bool big_endian>
2918 const Target::Target_info Target_arm<big_endian>::arm_info =
2919 {
2920   32,                   // size
2921   big_endian,           // is_big_endian
2922   elfcpp::EM_ARM,       // machine_code
2923   false,                // has_make_symbol
2924   false,                // has_resolve
2925   false,                // has_code_fill
2926   true,                 // is_default_stack_executable
2927   false,                // can_icf_inline_merge_sections
2928   '\0',                 // wrap_char
2929   "/usr/lib/libc.so.1", // dynamic_linker
2930   0x8000,               // default_text_segment_address
2931   0x1000,               // abi_pagesize (overridable by -z max-page-size)
2932   0x1000,               // common_pagesize (overridable by -z common-page-size)
2933   false,                // isolate_execinstr
2934   0,                    // rosegment_gap
2935   elfcpp::SHN_UNDEF,    // small_common_shndx
2936   elfcpp::SHN_UNDEF,    // large_common_shndx
2937   0,                    // small_common_section_flags
2938   0,                    // large_common_section_flags
2939   ".ARM.attributes",    // attributes_section
2940   "aeabi"               // attributes_vendor
2941 };
2942
2943 // Arm relocate functions class
2944 //
2945
2946 template<bool big_endian>
2947 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2948 {
2949  public:
2950   typedef enum
2951   {
2952     STATUS_OKAY,        // No error during relocation.
2953     STATUS_OVERFLOW,    // Relocation overflow.
2954     STATUS_BAD_RELOC    // Relocation cannot be applied.
2955   } Status;
2956
2957  private:
2958   typedef Relocate_functions<32, big_endian> Base;
2959   typedef Arm_relocate_functions<big_endian> This;
2960
2961   // Encoding of imm16 argument for movt and movw ARM instructions
2962   // from ARM ARM:
2963   //
2964   //     imm16 := imm4 | imm12
2965   //
2966   //  f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0
2967   // +-------+---------------+-------+-------+-----------------------+
2968   // |       |               |imm4   |       |imm12                  |
2969   // +-------+---------------+-------+-------+-----------------------+
2970
2971   // Extract the relocation addend from VAL based on the ARM
2972   // instruction encoding described above.
2973   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2974   extract_arm_movw_movt_addend(
2975       typename elfcpp::Swap<32, big_endian>::Valtype val)
2976   {
2977     // According to the Elf ABI for ARM Architecture the immediate
2978     // field is sign-extended to form the addend.
2979     return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff));
2980   }
2981
2982   // Insert X into VAL based on the ARM instruction encoding described
2983   // above.
2984   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2985   insert_val_arm_movw_movt(
2986       typename elfcpp::Swap<32, big_endian>::Valtype val,
2987       typename elfcpp::Swap<32, big_endian>::Valtype x)
2988   {
2989     val &= 0xfff0f000;
2990     val |= x & 0x0fff;
2991     val |= (x & 0xf000) << 4;
2992     return val;
2993   }
2994
2995   // Encoding of imm16 argument for movt and movw Thumb2 instructions
2996   // from ARM ARM:
2997   //
2998   //     imm16 := imm4 | i | imm3 | imm8
2999   //
3000   //  f e d c b a 9 8 7 6 5 4 3 2 1 0  f e d c b a 9 8 7 6 5 4 3 2 1 0
3001   // +---------+-+-----------+-------++-+-----+-------+---------------+
3002   // |         |i|           |imm4   || |imm3 |       |imm8           |
3003   // +---------+-+-----------+-------++-+-----+-------+---------------+
3004
3005   // Extract the relocation addend from VAL based on the Thumb2
3006   // instruction encoding described above.
3007   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3008   extract_thumb_movw_movt_addend(
3009       typename elfcpp::Swap<32, big_endian>::Valtype val)
3010   {
3011     // According to the Elf ABI for ARM Architecture the immediate
3012     // field is sign-extended to form the addend.
3013     return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
3014                                    | ((val >> 15) & 0x0800)
3015                                    | ((val >> 4) & 0x0700)
3016                                    | (val & 0x00ff));
3017   }
3018
3019   // Insert X into VAL based on the Thumb2 instruction encoding
3020   // described above.
3021   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3022   insert_val_thumb_movw_movt(
3023       typename elfcpp::Swap<32, big_endian>::Valtype val,
3024       typename elfcpp::Swap<32, big_endian>::Valtype x)
3025   {
3026     val &= 0xfbf08f00;
3027     val |= (x & 0xf000) << 4;
3028     val |= (x & 0x0800) << 15;
3029     val |= (x & 0x0700) << 4;
3030     val |= (x & 0x00ff);
3031     return val;
3032   }
3033
3034   // Calculate the smallest constant Kn for the specified residual.
3035   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3036   static uint32_t
3037   calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3038   {
3039     int32_t msb;
3040
3041     if (residual == 0)
3042       return 0;
3043     // Determine the most significant bit in the residual and
3044     // align the resulting value to a 2-bit boundary.
3045     for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3046       ;
3047     // The desired shift is now (msb - 6), or zero, whichever
3048     // is the greater.
3049     return (((msb - 6) < 0) ? 0 : (msb - 6));
3050   }
3051
3052   // Calculate the final residual for the specified group index.
3053   // If the passed group index is less than zero, the method will return
3054   // the value of the specified residual without any change.
3055   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3056   static typename elfcpp::Swap<32, big_endian>::Valtype
3057   calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3058                     const int group)
3059   {
3060     for (int n = 0; n <= group; n++)
3061       {
3062         // Calculate which part of the value to mask.
3063         uint32_t shift = calc_grp_kn(residual);
3064         // Calculate the residual for the next time around.
3065         residual &= ~(residual & (0xff << shift));
3066       }
3067
3068     return residual;
3069   }
3070
3071   // Calculate the value of Gn for the specified group index.
3072   // We return it in the form of an encoded constant-and-rotation.
3073   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3074   static typename elfcpp::Swap<32, big_endian>::Valtype
3075   calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3076               const int group)
3077   {
3078     typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3079     uint32_t shift = 0;
3080
3081     for (int n = 0; n <= group; n++)
3082       {
3083         // Calculate which part of the value to mask.
3084         shift = calc_grp_kn(residual);
3085         // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3086         gn = residual & (0xff << shift);
3087         // Calculate the residual for the next time around.
3088         residual &= ~gn;
3089       }
3090     // Return Gn in the form of an encoded constant-and-rotation.
3091     return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3092   }
3093
3094  public:
3095   // Handle ARM long branches.
3096   static typename This::Status
3097   arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3098                     unsigned char*, const Sized_symbol<32>*,
3099                     const Arm_relobj<big_endian>*, unsigned int,
3100                     const Symbol_value<32>*, Arm_address, Arm_address, bool);
3101
3102   // Handle THUMB long branches.
3103   static typename This::Status
3104   thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3105                       unsigned char*, const Sized_symbol<32>*,
3106                       const Arm_relobj<big_endian>*, unsigned int,
3107                       const Symbol_value<32>*, Arm_address, Arm_address, bool);
3108
3109
3110   // Return the branch offset of a 32-bit THUMB branch.
3111   static inline int32_t
3112   thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3113   {
3114     // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3115     // involving the J1 and J2 bits.
3116     uint32_t s = (upper_insn & (1U << 10)) >> 10;
3117     uint32_t upper = upper_insn & 0x3ffU;
3118     uint32_t lower = lower_insn & 0x7ffU;
3119     uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3120     uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3121     uint32_t i1 = j1 ^ s ? 0 : 1;
3122     uint32_t i2 = j2 ^ s ? 0 : 1;
3123
3124     return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3125                                    | (upper << 12) | (lower << 1));
3126   }
3127
3128   // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3129   // UPPER_INSN is the original upper instruction of the branch.  Caller is
3130   // responsible for overflow checking and BLX offset adjustment.
3131   static inline uint16_t
3132   thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3133   {
3134     uint32_t s = offset < 0 ? 1 : 0;
3135     uint32_t bits = static_cast<uint32_t>(offset);
3136     return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3137   }
3138
3139   // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3140   // LOWER_INSN is the original lower instruction of the branch.  Caller is
3141   // responsible for overflow checking and BLX offset adjustment.
3142   static inline uint16_t
3143   thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3144   {
3145     uint32_t s = offset < 0 ? 1 : 0;
3146     uint32_t bits = static_cast<uint32_t>(offset);
3147     return ((lower_insn & ~0x2fffU)
3148             | ((((bits >> 23) & 1) ^ !s) << 13)
3149             | ((((bits >> 22) & 1) ^ !s) << 11)
3150             | ((bits >> 1) & 0x7ffU));
3151   }
3152
3153   // Return the branch offset of a 32-bit THUMB conditional branch.
3154   static inline int32_t
3155   thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3156   {
3157     uint32_t s = (upper_insn & 0x0400U) >> 10;
3158     uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3159     uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3160     uint32_t lower = (lower_insn & 0x07ffU);
3161     uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3162
3163     return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3164   }
3165
3166   // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3167   // instruction.  UPPER_INSN is the original upper instruction of the branch.
3168   // Caller is responsible for overflow checking.
3169   static inline uint16_t
3170   thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3171   {
3172     uint32_t s = offset < 0 ? 1 : 0;
3173     uint32_t bits = static_cast<uint32_t>(offset);
3174     return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3175   }
3176
3177   // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3178   // instruction.  LOWER_INSN is the original lower instruction of the branch.
3179   // The caller is responsible for overflow checking.
3180   static inline uint16_t
3181   thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3182   {
3183     uint32_t bits = static_cast<uint32_t>(offset);
3184     uint32_t j2 = (bits & 0x00080000U) >> 19;
3185     uint32_t j1 = (bits & 0x00040000U) >> 18;
3186     uint32_t lo = (bits & 0x00000ffeU) >> 1;
3187
3188     return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3189   }
3190
3191   // R_ARM_ABS8: S + A
3192   static inline typename This::Status
3193   abs8(unsigned char* view,
3194        const Sized_relobj_file<32, big_endian>* object,
3195        const Symbol_value<32>* psymval)
3196   {
3197     typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3198     Valtype* wv = reinterpret_cast<Valtype*>(view);
3199     Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3200     int32_t addend = Bits<8>::sign_extend32(val);
3201     Arm_address x = psymval->value(object, addend);
3202     val = Bits<32>::bit_select32(val, x, 0xffU);
3203     elfcpp::Swap<8, big_endian>::writeval(wv, val);
3204
3205     // R_ARM_ABS8 permits signed or unsigned results.
3206     return (Bits<8>::has_signed_unsigned_overflow32(x)
3207             ? This::STATUS_OVERFLOW
3208             : This::STATUS_OKAY);
3209   }
3210
3211   // R_ARM_THM_ABS5: S + A
3212   static inline typename This::Status
3213   thm_abs5(unsigned char* view,
3214        const Sized_relobj_file<32, big_endian>* object,
3215        const Symbol_value<32>* psymval)
3216   {
3217     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3218     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3219     Valtype* wv = reinterpret_cast<Valtype*>(view);
3220     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3221     Reltype addend = (val & 0x7e0U) >> 6;
3222     Reltype x = psymval->value(object, addend);
3223     val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3224     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3225     return (Bits<5>::has_overflow32(x)
3226             ? This::STATUS_OVERFLOW
3227             : This::STATUS_OKAY);
3228   }
3229
3230   // R_ARM_ABS12: S + A
3231   static inline typename This::Status
3232   abs12(unsigned char* view,
3233         const Sized_relobj_file<32, big_endian>* object,
3234         const Symbol_value<32>* psymval)
3235   {
3236     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3237     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3238     Valtype* wv = reinterpret_cast<Valtype*>(view);
3239     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3240     Reltype addend = val & 0x0fffU;
3241     Reltype x = psymval->value(object, addend);
3242     val = Bits<32>::bit_select32(val, x, 0x0fffU);
3243     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3244     return (Bits<12>::has_overflow32(x)
3245             ? This::STATUS_OVERFLOW
3246             : This::STATUS_OKAY);
3247   }
3248
3249   // R_ARM_ABS16: S + A
3250   static inline typename This::Status
3251   abs16(unsigned char* view,
3252         const Sized_relobj_file<32, big_endian>* object,
3253         const Symbol_value<32>* psymval)
3254   {
3255     typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
3256     Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view);
3257     int32_t addend = Bits<16>::sign_extend32(val);
3258     Arm_address x = psymval->value(object, addend);
3259     val = Bits<32>::bit_select32(val, x, 0xffffU);
3260     elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val);
3261
3262     // R_ARM_ABS16 permits signed or unsigned results.
3263     return (Bits<16>::has_signed_unsigned_overflow32(x)
3264             ? This::STATUS_OVERFLOW
3265             : This::STATUS_OKAY);
3266   }
3267
3268   // R_ARM_ABS32: (S + A) | T
3269   static inline typename This::Status
3270   abs32(unsigned char* view,
3271         const Sized_relobj_file<32, big_endian>* object,
3272         const Symbol_value<32>* psymval,
3273         Arm_address thumb_bit)
3274   {
3275     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3276     Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3277     Valtype x = psymval->value(object, addend) | thumb_bit;
3278     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3279     return This::STATUS_OKAY;
3280   }
3281
3282   // R_ARM_REL32: (S + A) | T - P
3283   static inline typename This::Status
3284   rel32(unsigned char* view,
3285         const Sized_relobj_file<32, big_endian>* object,
3286         const Symbol_value<32>* psymval,
3287         Arm_address address,
3288         Arm_address thumb_bit)
3289   {
3290     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3291     Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3292     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3293     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3294     return This::STATUS_OKAY;
3295   }
3296
3297   // R_ARM_THM_JUMP24: (S + A) | T - P
3298   static typename This::Status
3299   thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3300              const Symbol_value<32>* psymval, Arm_address address,
3301              Arm_address thumb_bit);
3302
3303   // R_ARM_THM_JUMP6: S + A â€“ P
3304   static inline typename This::Status
3305   thm_jump6(unsigned char* view,
3306             const Sized_relobj_file<32, big_endian>* object,
3307             const Symbol_value<32>* psymval,
3308             Arm_address address)
3309   {
3310     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3311     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3312     Valtype* wv = reinterpret_cast<Valtype*>(view);
3313     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3314     // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3315     Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3316     Reltype x = (psymval->value(object, addend) - address);
3317     val = (val & 0xfd07) | ((x  & 0x0040) << 3) | ((val & 0x003e) << 2);
3318     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3319     // CZB does only forward jumps.
3320     return ((x > 0x007e)
3321             ? This::STATUS_OVERFLOW
3322             : This::STATUS_OKAY);
3323   }
3324
3325   // R_ARM_THM_JUMP8: S + A â€“ P
3326   static inline typename This::Status
3327   thm_jump8(unsigned char* view,
3328             const Sized_relobj_file<32, big_endian>* object,
3329             const Symbol_value<32>* psymval,
3330             Arm_address address)
3331   {
3332     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3333     Valtype* wv = reinterpret_cast<Valtype*>(view);
3334     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3335     int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1);
3336     int32_t x = (psymval->value(object, addend) - address);
3337     elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00)
3338                                                 | ((x & 0x01fe) >> 1)));
3339     // We do a 9-bit overflow check because x is right-shifted by 1 bit.
3340     return (Bits<9>::has_overflow32(x)
3341             ? This::STATUS_OVERFLOW
3342             : This::STATUS_OKAY);
3343   }
3344
3345   // R_ARM_THM_JUMP11: S + A â€“ P
3346   static inline typename This::Status
3347   thm_jump11(unsigned char* view,
3348             const Sized_relobj_file<32, big_endian>* object,
3349             const Symbol_value<32>* psymval,
3350             Arm_address address)
3351   {
3352     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3353     Valtype* wv = reinterpret_cast<Valtype*>(view);
3354     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3355     int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1);
3356     int32_t x = (psymval->value(object, addend) - address);
3357     elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800)
3358                                                 | ((x & 0x0ffe) >> 1)));
3359     // We do a 12-bit overflow check because x is right-shifted by 1 bit.
3360     return (Bits<12>::has_overflow32(x)
3361             ? This::STATUS_OVERFLOW
3362             : This::STATUS_OKAY);
3363   }
3364
3365   // R_ARM_BASE_PREL: B(S) + A - P
3366   static inline typename This::Status
3367   base_prel(unsigned char* view,
3368             Arm_address origin,
3369             Arm_address address)
3370   {
3371     Base::rel32(view, origin - address);
3372     return STATUS_OKAY;
3373   }
3374
3375   // R_ARM_BASE_ABS: B(S) + A
3376   static inline typename This::Status
3377   base_abs(unsigned char* view,
3378            Arm_address origin)
3379   {
3380     Base::rel32(view, origin);
3381     return STATUS_OKAY;
3382   }
3383
3384   // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3385   static inline typename This::Status
3386   got_brel(unsigned char* view,
3387            typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3388   {
3389     Base::rel32(view, got_offset);
3390     return This::STATUS_OKAY;
3391   }
3392
3393   // R_ARM_GOT_PREL: GOT(S) + A - P
3394   static inline typename This::Status
3395   got_prel(unsigned char* view,
3396            Arm_address got_entry,
3397            Arm_address address)
3398   {
3399     Base::rel32(view, got_entry - address);
3400     return This::STATUS_OKAY;
3401   }
3402
3403   // R_ARM_PREL: (S + A) | T - P
3404   static inline typename This::Status
3405   prel31(unsigned char* view,
3406          const Sized_relobj_file<32, big_endian>* object,
3407          const Symbol_value<32>* psymval,
3408          Arm_address address,
3409          Arm_address thumb_bit)
3410   {
3411     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3412     Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3413     Valtype addend = Bits<31>::sign_extend32(val);
3414     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3415     val = Bits<32>::bit_select32(val, x, 0x7fffffffU);
3416     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val);
3417     return (Bits<31>::has_overflow32(x)
3418             ? This::STATUS_OVERFLOW
3419             : This::STATUS_OKAY);
3420   }
3421
3422   // R_ARM_MOVW_ABS_NC: (S + A) | T     (relative address base is )
3423   // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3424   // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3425   // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3426   static inline typename This::Status
3427   movw(unsigned char* view,
3428        const Sized_relobj_file<32, big_endian>* object,
3429        const Symbol_value<32>* psymval,
3430        Arm_address relative_address_base,
3431        Arm_address thumb_bit,
3432        bool check_overflow)
3433   {
3434     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3435     Valtype* wv = reinterpret_cast<Valtype*>(view);
3436     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3437     Valtype addend = This::extract_arm_movw_movt_addend(val);
3438     Valtype x = ((psymval->value(object, addend) | thumb_bit)
3439                  - relative_address_base);
3440     val = This::insert_val_arm_movw_movt(val, x);
3441     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3442     return ((check_overflow && Bits<16>::has_overflow32(x))
3443             ? This::STATUS_OVERFLOW
3444             : This::STATUS_OKAY);
3445   }
3446
3447   // R_ARM_MOVT_ABS: S + A      (relative address base is 0)
3448   // R_ARM_MOVT_PREL: S + A - P
3449   // R_ARM_MOVT_BREL: S + A - B(S)
3450   static inline typename This::Status
3451   movt(unsigned char* view,
3452        const Sized_relobj_file<32, big_endian>* object,
3453        const Symbol_value<32>* psymval,
3454        Arm_address relative_address_base)
3455   {
3456     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3457     Valtype* wv = reinterpret_cast<Valtype*>(view);
3458     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3459     Valtype addend = This::extract_arm_movw_movt_addend(val);
3460     Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3461     val = This::insert_val_arm_movw_movt(val, x);
3462     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3463     // FIXME: IHI0044D says that we should check for overflow.
3464     return This::STATUS_OKAY;
3465   }
3466
3467   // R_ARM_THM_MOVW_ABS_NC: S + A | T           (relative_address_base is 0)
3468   // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3469   // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3470   // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3471   static inline typename This::Status
3472   thm_movw(unsigned char* view,
3473            const Sized_relobj_file<32, big_endian>* object,
3474            const Symbol_value<32>* psymval,
3475            Arm_address relative_address_base,
3476            Arm_address thumb_bit,
3477            bool check_overflow)
3478   {
3479     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3480     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3481     Valtype* wv = reinterpret_cast<Valtype*>(view);
3482     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3483                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3484     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3485     Reltype x =
3486       (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3487     val = This::insert_val_thumb_movw_movt(val, x);
3488     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3489     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3490     return ((check_overflow && Bits<16>::has_overflow32(x))
3491             ? This::STATUS_OVERFLOW
3492             : This::STATUS_OKAY);
3493   }
3494
3495   // R_ARM_THM_MOVT_ABS: S + A          (relative address base is 0)
3496   // R_ARM_THM_MOVT_PREL: S + A - P
3497   // R_ARM_THM_MOVT_BREL: S + A - B(S)
3498   static inline typename This::Status
3499   thm_movt(unsigned char* view,
3500            const Sized_relobj_file<32, big_endian>* object,
3501            const Symbol_value<32>* psymval,
3502            Arm_address relative_address_base)
3503   {
3504     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3505     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3506     Valtype* wv = reinterpret_cast<Valtype*>(view);
3507     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3508                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3509     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3510     Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3511     val = This::insert_val_thumb_movw_movt(val, x);
3512     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3513     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3514     return This::STATUS_OKAY;
3515   }
3516
3517   // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3518   static inline typename This::Status
3519   thm_alu11(unsigned char* view,
3520             const Sized_relobj_file<32, big_endian>* object,
3521             const Symbol_value<32>* psymval,
3522             Arm_address address,
3523             Arm_address thumb_bit)
3524   {
3525     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3526     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3527     Valtype* wv = reinterpret_cast<Valtype*>(view);
3528     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3529                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3530
3531     //        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
3532     // -----------------------------------------------------------------------
3533     // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd     |imm8
3534     // ADDW   1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd     |imm8
3535     // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd     |imm8
3536     // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd     |imm8
3537     // SUBW   1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd     |imm8
3538     // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd     |imm8
3539
3540     // Determine a sign for the addend.
3541     const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3542                       || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3543     // Thumb2 addend encoding:
3544     // imm12 := i | imm3 | imm8
3545     int32_t addend = (insn & 0xff)
3546                      | ((insn & 0x00007000) >> 4)
3547                      | ((insn & 0x04000000) >> 15);
3548     // Apply a sign to the added.
3549     addend *= sign;
3550
3551     int32_t x = (psymval->value(object, addend) | thumb_bit)
3552                 - (address & 0xfffffffc);
3553     Reltype val = abs(x);
3554     // Mask out the value and a distinct part of the ADD/SUB opcode
3555     // (bits 7:5 of opword).
3556     insn = (insn & 0xfb0f8f00)
3557            | (val & 0xff)
3558            | ((val & 0x700) << 4)
3559            | ((val & 0x800) << 15);
3560     // Set the opcode according to whether the value to go in the
3561     // place is negative.
3562     if (x < 0)
3563       insn |= 0x00a00000;
3564
3565     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3566     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3567     return ((val > 0xfff) ?
3568             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3569   }
3570
3571   // R_ARM_THM_PC8: S + A - Pa (Thumb)
3572   static inline typename This::Status
3573   thm_pc8(unsigned char* view,
3574           const Sized_relobj_file<32, big_endian>* object,
3575           const Symbol_value<32>* psymval,
3576           Arm_address address)
3577   {
3578     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3579     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3580     Valtype* wv = reinterpret_cast<Valtype*>(view);
3581     Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3582     Reltype addend = ((insn & 0x00ff) << 2);
3583     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3584     Reltype val = abs(x);
3585     insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3586
3587     elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3588     return ((val > 0x03fc)
3589             ? This::STATUS_OVERFLOW
3590             : This::STATUS_OKAY);
3591   }
3592
3593   // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3594   static inline typename This::Status
3595   thm_pc12(unsigned char* view,
3596            const Sized_relobj_file<32, big_endian>* object,
3597            const Symbol_value<32>* psymval,
3598            Arm_address address)
3599   {
3600     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3601     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3602     Valtype* wv = reinterpret_cast<Valtype*>(view);
3603     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3604                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3605     // Determine a sign for the addend (positive if the U bit is 1).
3606     const int sign = (insn & 0x00800000) ? 1 : -1;
3607     int32_t addend = (insn & 0xfff);
3608     // Apply a sign to the added.
3609     addend *= sign;
3610
3611     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3612     Reltype val = abs(x);
3613     // Mask out and apply the value and the U bit.
3614     insn = (insn & 0xff7ff000) | (val & 0xfff);
3615     // Set the U bit according to whether the value to go in the
3616     // place is positive.
3617     if (x >= 0)
3618       insn |= 0x00800000;
3619
3620     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3621     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3622     return ((val > 0xfff) ?
3623             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3624   }
3625
3626   // R_ARM_V4BX
3627   static inline typename This::Status
3628   v4bx(const Relocate_info<32, big_endian>* relinfo,
3629        unsigned char* view,
3630        const Arm_relobj<big_endian>* object,
3631        const Arm_address address,
3632        const bool is_interworking)
3633   {
3634
3635     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3636     Valtype* wv = reinterpret_cast<Valtype*>(view);
3637     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3638
3639     // Ensure that we have a BX instruction.
3640     gold_assert((val & 0x0ffffff0) == 0x012fff10);
3641     const uint32_t reg = (val & 0xf);
3642     if (is_interworking && reg != 0xf)
3643       {
3644         Stub_table<big_endian>* stub_table =
3645             object->stub_table(relinfo->data_shndx);
3646         gold_assert(stub_table != NULL);
3647
3648         Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3649         gold_assert(stub != NULL);
3650
3651         int32_t veneer_address =
3652             stub_table->address() + stub->offset() - 8 - address;
3653         gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3654                     && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3655         // Replace with a branch to veneer (B <addr>)
3656         val = (val & 0xf0000000) | 0x0a000000
3657               | ((veneer_address >> 2) & 0x00ffffff);
3658       }
3659     else
3660       {
3661         // Preserve Rm (lowest four bits) and the condition code
3662         // (highest four bits). Other bits encode MOV PC,Rm.
3663         val = (val & 0xf000000f) | 0x01a0f000;
3664       }
3665     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3666     return This::STATUS_OKAY;
3667   }
3668
3669   // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3670   // R_ARM_ALU_PC_G0:    ((S + A) | T) - P
3671   // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3672   // R_ARM_ALU_PC_G1:    ((S + A) | T) - P
3673   // R_ARM_ALU_PC_G2:    ((S + A) | T) - P
3674   // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3675   // R_ARM_ALU_SB_G0:    ((S + A) | T) - B(S)
3676   // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3677   // R_ARM_ALU_SB_G1:    ((S + A) | T) - B(S)
3678   // R_ARM_ALU_SB_G2:    ((S + A) | T) - B(S)
3679   static inline typename This::Status
3680   arm_grp_alu(unsigned char* view,
3681         const Sized_relobj_file<32, big_endian>* object,
3682         const Symbol_value<32>* psymval,
3683         const int group,
3684         Arm_address address,
3685         Arm_address thumb_bit,
3686         bool check_overflow)
3687   {
3688     gold_assert(group >= 0 && group < 3);
3689     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3690     Valtype* wv = reinterpret_cast<Valtype*>(view);
3691     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3692
3693     // ALU group relocations are allowed only for the ADD/SUB instructions.
3694     // (0x00800000 - ADD, 0x00400000 - SUB)
3695     const Valtype opcode = insn & 0x01e00000;
3696     if (opcode != 0x00800000 && opcode != 0x00400000)
3697       return This::STATUS_BAD_RELOC;
3698
3699     // Determine a sign for the addend.
3700     const int sign = (opcode == 0x00800000) ? 1 : -1;
3701     // shifter = rotate_imm * 2
3702     const uint32_t shifter = (insn & 0xf00) >> 7;
3703     // Initial addend value.
3704     int32_t addend = insn & 0xff;
3705     // Rotate addend right by shifter.
3706     addend = (addend >> shifter) | (addend << (32 - shifter));
3707     // Apply a sign to the added.
3708     addend *= sign;
3709
3710     int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3711     Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3712     // Check for overflow if required
3713     if (check_overflow
3714         && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3715       return This::STATUS_OVERFLOW;
3716
3717     // Mask out the value and the ADD/SUB part of the opcode; take care
3718     // not to destroy the S bit.
3719     insn &= 0xff1ff000;
3720     // Set the opcode according to whether the value to go in the
3721     // place is negative.
3722     insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3723     // Encode the offset (encoded Gn).
3724     insn |= gn;
3725
3726     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3727     return This::STATUS_OKAY;
3728   }
3729
3730   // R_ARM_LDR_PC_G0: S + A - P
3731   // R_ARM_LDR_PC_G1: S + A - P
3732   // R_ARM_LDR_PC_G2: S + A - P
3733   // R_ARM_LDR_SB_G0: S + A - B(S)
3734   // R_ARM_LDR_SB_G1: S + A - B(S)
3735   // R_ARM_LDR_SB_G2: S + A - B(S)
3736   static inline typename This::Status
3737   arm_grp_ldr(unsigned char* view,
3738         const Sized_relobj_file<32, big_endian>* object,
3739         const Symbol_value<32>* psymval,
3740         const int group,
3741         Arm_address address)
3742   {
3743     gold_assert(group >= 0 && group < 3);
3744     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3745     Valtype* wv = reinterpret_cast<Valtype*>(view);
3746     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3747
3748     const int sign = (insn & 0x00800000) ? 1 : -1;
3749     int32_t addend = (insn & 0xfff) * sign;
3750     int32_t x = (psymval->value(object, addend) - address);
3751     // Calculate the relevant G(n-1) value to obtain this stage residual.
3752     Valtype residual =
3753         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3754     if (residual >= 0x1000)
3755       return This::STATUS_OVERFLOW;
3756
3757     // Mask out the value and U bit.
3758     insn &= 0xff7ff000;
3759     // Set the U bit for non-negative values.
3760     if (x >= 0)
3761       insn |= 0x00800000;
3762     insn |= residual;
3763
3764     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3765     return This::STATUS_OKAY;
3766   }
3767
3768   // R_ARM_LDRS_PC_G0: S + A - P
3769   // R_ARM_LDRS_PC_G1: S + A - P
3770   // R_ARM_LDRS_PC_G2: S + A - P
3771   // R_ARM_LDRS_SB_G0: S + A - B(S)
3772   // R_ARM_LDRS_SB_G1: S + A - B(S)
3773   // R_ARM_LDRS_SB_G2: S + A - B(S)
3774   static inline typename This::Status
3775   arm_grp_ldrs(unsigned char* view,
3776         const Sized_relobj_file<32, big_endian>* object,
3777         const Symbol_value<32>* psymval,
3778         const int group,
3779         Arm_address address)
3780   {
3781     gold_assert(group >= 0 && group < 3);
3782     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3783     Valtype* wv = reinterpret_cast<Valtype*>(view);
3784     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3785
3786     const int sign = (insn & 0x00800000) ? 1 : -1;
3787     int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3788     int32_t x = (psymval->value(object, addend) - address);
3789     // Calculate the relevant G(n-1) value to obtain this stage residual.
3790     Valtype residual =
3791         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3792    if (residual >= 0x100)
3793       return This::STATUS_OVERFLOW;
3794
3795     // Mask out the value and U bit.
3796     insn &= 0xff7ff0f0;
3797     // Set the U bit for non-negative values.
3798     if (x >= 0)
3799       insn |= 0x00800000;
3800     insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3801
3802     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3803     return This::STATUS_OKAY;
3804   }
3805
3806   // R_ARM_LDC_PC_G0: S + A - P
3807   // R_ARM_LDC_PC_G1: S + A - P
3808   // R_ARM_LDC_PC_G2: S + A - P
3809   // R_ARM_LDC_SB_G0: S + A - B(S)
3810   // R_ARM_LDC_SB_G1: S + A - B(S)
3811   // R_ARM_LDC_SB_G2: S + A - B(S)
3812   static inline typename This::Status
3813   arm_grp_ldc(unsigned char* view,
3814       const Sized_relobj_file<32, big_endian>* object,
3815       const Symbol_value<32>* psymval,
3816       const int group,
3817       Arm_address address)
3818   {
3819     gold_assert(group >= 0 && group < 3);
3820     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3821     Valtype* wv = reinterpret_cast<Valtype*>(view);
3822     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3823
3824     const int sign = (insn & 0x00800000) ? 1 : -1;
3825     int32_t addend = ((insn & 0xff) << 2) * sign;
3826     int32_t x = (psymval->value(object, addend) - address);
3827     // Calculate the relevant G(n-1) value to obtain this stage residual.
3828     Valtype residual =
3829       Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3830     if ((residual & 0x3) != 0 || residual >= 0x400)
3831       return This::STATUS_OVERFLOW;
3832
3833     // Mask out the value and U bit.
3834     insn &= 0xff7fff00;
3835     // Set the U bit for non-negative values.
3836     if (x >= 0)
3837       insn |= 0x00800000;
3838     insn |= (residual >> 2);
3839
3840     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3841     return This::STATUS_OKAY;
3842   }
3843 };
3844
3845 // Relocate ARM long branches.  This handles relocation types
3846 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3847 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3848 // undefined and we do not use PLT in this relocation.  In such a case,
3849 // the branch is converted into an NOP.
3850
3851 template<bool big_endian>
3852 typename Arm_relocate_functions<big_endian>::Status
3853 Arm_relocate_functions<big_endian>::arm_branch_common(
3854     unsigned int r_type,
3855     const Relocate_info<32, big_endian>* relinfo,
3856     unsigned char* view,
3857     const Sized_symbol<32>* gsym,
3858     const Arm_relobj<big_endian>* object,
3859     unsigned int r_sym,
3860     const Symbol_value<32>* psymval,
3861     Arm_address address,
3862     Arm_address thumb_bit,
3863     bool is_weakly_undefined_without_plt)
3864 {
3865   typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3866   Valtype* wv = reinterpret_cast<Valtype*>(view);
3867   Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3868
3869   bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3870                     && ((val & 0x0f000000UL) == 0x0a000000UL);
3871   bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3872   bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3873                           && ((val & 0x0f000000UL) == 0x0b000000UL);
3874   bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3875   bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3876
3877   // Check that the instruction is valid.
3878   if (r_type == elfcpp::R_ARM_CALL)
3879     {
3880       if (!insn_is_uncond_bl && !insn_is_blx)
3881         return This::STATUS_BAD_RELOC;
3882     }
3883   else if (r_type == elfcpp::R_ARM_JUMP24)
3884     {
3885       if (!insn_is_b && !insn_is_cond_bl)
3886         return This::STATUS_BAD_RELOC;
3887     }
3888   else if (r_type == elfcpp::R_ARM_PLT32)
3889     {
3890       if (!insn_is_any_branch)
3891         return This::STATUS_BAD_RELOC;
3892     }
3893   else if (r_type == elfcpp::R_ARM_XPC25)
3894     {
3895       // FIXME: AAELF document IH0044C does not say much about it other
3896       // than it being obsolete.
3897       if (!insn_is_any_branch)
3898         return This::STATUS_BAD_RELOC;
3899     }
3900   else
3901     gold_unreachable();
3902
3903   // A branch to an undefined weak symbol is turned into a jump to
3904   // the next instruction unless a PLT entry will be created.
3905   // Do the same for local undefined symbols.
3906   // The jump to the next instruction is optimized as a NOP depending
3907   // on the architecture.
3908   const Target_arm<big_endian>* arm_target =
3909     Target_arm<big_endian>::default_target();
3910   if (is_weakly_undefined_without_plt)
3911     {
3912       gold_assert(!parameters->options().relocatable());
3913       Valtype cond = val & 0xf0000000U;
3914       if (arm_target->may_use_arm_nop())
3915         val = cond | 0x0320f000;
3916       else
3917         val = cond | 0x01a00000;        // Using pre-UAL nop: mov r0, r0.
3918       elfcpp::Swap<32, big_endian>::writeval(wv, val);
3919       return This::STATUS_OKAY;
3920     }
3921
3922   Valtype addend = Bits<26>::sign_extend32(val << 2);
3923   Valtype branch_target = psymval->value(object, addend);
3924   int32_t branch_offset = branch_target - address;
3925
3926   // We need a stub if the branch offset is too large or if we need
3927   // to switch mode.
3928   bool may_use_blx = arm_target->may_use_v5t_interworking();
3929   Reloc_stub* stub = NULL;
3930
3931   if (!parameters->options().relocatable()
3932       && (Bits<26>::has_overflow32(branch_offset)
3933           || ((thumb_bit != 0)
3934               && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3935     {
3936       Valtype unadjusted_branch_target = psymval->value(object, 0);
3937
3938       Stub_type stub_type =
3939         Reloc_stub::stub_type_for_reloc(r_type, address,
3940                                         unadjusted_branch_target,
3941                                         (thumb_bit != 0));
3942       if (stub_type != arm_stub_none)
3943         {
3944           Stub_table<big_endian>* stub_table =
3945             object->stub_table(relinfo->data_shndx);
3946           gold_assert(stub_table != NULL);
3947
3948           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3949           stub = stub_table->find_reloc_stub(stub_key);
3950           gold_assert(stub != NULL);
3951           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3952           branch_target = stub_table->address() + stub->offset() + addend;
3953           branch_offset = branch_target - address;
3954           gold_assert(!Bits<26>::has_overflow32(branch_offset));
3955         }
3956     }
3957
3958   // At this point, if we still need to switch mode, the instruction
3959   // must either be a BLX or a BL that can be converted to a BLX.
3960   if (thumb_bit != 0)
3961     {
3962       // Turn BL to BLX.
3963       gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3964       val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3965     }
3966
3967   val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL);
3968   elfcpp::Swap<32, big_endian>::writeval(wv, val);
3969   return (Bits<26>::has_overflow32(branch_offset)
3970           ? This::STATUS_OVERFLOW
3971           : This::STATUS_OKAY);
3972 }
3973
3974 // Relocate THUMB long branches.  This handles relocation types
3975 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3976 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3977 // undefined and we do not use PLT in this relocation.  In such a case,
3978 // the branch is converted into an NOP.
3979
3980 template<bool big_endian>
3981 typename Arm_relocate_functions<big_endian>::Status
3982 Arm_relocate_functions<big_endian>::thumb_branch_common(
3983     unsigned int r_type,
3984     const Relocate_info<32, big_endian>* relinfo,
3985     unsigned char* view,
3986     const Sized_symbol<32>* gsym,
3987     const Arm_relobj<big_endian>* object,
3988     unsigned int r_sym,
3989     const Symbol_value<32>* psymval,
3990     Arm_address address,
3991     Arm_address thumb_bit,
3992     bool is_weakly_undefined_without_plt)
3993 {
3994   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3995   Valtype* wv = reinterpret_cast<Valtype*>(view);
3996   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
3997   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
3998
3999   // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
4000   // into account.
4001   bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
4002   bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
4003
4004   // Check that the instruction is valid.
4005   if (r_type == elfcpp::R_ARM_THM_CALL)
4006     {
4007       if (!is_bl_insn && !is_blx_insn)
4008         return This::STATUS_BAD_RELOC;
4009     }
4010   else if (r_type == elfcpp::R_ARM_THM_JUMP24)
4011     {
4012       // This cannot be a BLX.
4013       if (!is_bl_insn)
4014         return This::STATUS_BAD_RELOC;
4015     }
4016   else if (r_type == elfcpp::R_ARM_THM_XPC22)
4017     {
4018       // Check for Thumb to Thumb call.
4019       if (!is_blx_insn)
4020         return This::STATUS_BAD_RELOC;
4021       if (thumb_bit != 0)
4022         {
4023           gold_warning(_("%s: Thumb BLX instruction targets "
4024                          "thumb function '%s'."),
4025                          object->name().c_str(),
4026                          (gsym ? gsym->name() : "(local)"));
4027           // Convert BLX to BL.
4028           lower_insn |= 0x1000U;
4029         }
4030     }
4031   else
4032     gold_unreachable();
4033
4034   // A branch to an undefined weak symbol is turned into a jump to
4035   // the next instruction unless a PLT entry will be created.
4036   // The jump to the next instruction is optimized as a NOP.W for
4037   // Thumb-2 enabled architectures.
4038   const Target_arm<big_endian>* arm_target =
4039     Target_arm<big_endian>::default_target();
4040   if (is_weakly_undefined_without_plt)
4041     {
4042       gold_assert(!parameters->options().relocatable());
4043       if (arm_target->may_use_thumb2_nop())
4044         {
4045           elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4046           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4047         }
4048       else
4049         {
4050           elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4051           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4052         }
4053       return This::STATUS_OKAY;
4054     }
4055
4056   int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4057   Arm_address branch_target = psymval->value(object, addend);
4058
4059   // For BLX, bit 1 of target address comes from bit 1 of base address.
4060   bool may_use_blx = arm_target->may_use_v5t_interworking();
4061   if (thumb_bit == 0 && may_use_blx)
4062     branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4063
4064   int32_t branch_offset = branch_target - address;
4065
4066   // We need a stub if the branch offset is too large or if we need
4067   // to switch mode.
4068   bool thumb2 = arm_target->using_thumb2();
4069   if (!parameters->options().relocatable()
4070       && ((!thumb2 && Bits<23>::has_overflow32(branch_offset))
4071           || (thumb2 && Bits<25>::has_overflow32(branch_offset))
4072           || ((thumb_bit == 0)
4073               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4074                   || r_type == elfcpp::R_ARM_THM_JUMP24))))
4075     {
4076       Arm_address unadjusted_branch_target = psymval->value(object, 0);
4077
4078       Stub_type stub_type =
4079         Reloc_stub::stub_type_for_reloc(r_type, address,
4080                                         unadjusted_branch_target,
4081                                         (thumb_bit != 0));
4082
4083       if (stub_type != arm_stub_none)
4084         {
4085           Stub_table<big_endian>* stub_table =
4086             object->stub_table(relinfo->data_shndx);
4087           gold_assert(stub_table != NULL);
4088
4089           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4090           Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4091           gold_assert(stub != NULL);
4092           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4093           branch_target = stub_table->address() + stub->offset() + addend;
4094           if (thumb_bit == 0 && may_use_blx)
4095             branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4096           branch_offset = branch_target - address;
4097         }
4098     }
4099
4100   // At this point, if we still need to switch mode, the instruction
4101   // must either be a BLX or a BL that can be converted to a BLX.
4102   if (thumb_bit == 0)
4103     {
4104       gold_assert(may_use_blx
4105                   && (r_type == elfcpp::R_ARM_THM_CALL
4106                       || r_type == elfcpp::R_ARM_THM_XPC22));
4107       // Make sure this is a BLX.
4108       lower_insn &= ~0x1000U;
4109     }
4110   else
4111     {
4112       // Make sure this is a BL.
4113       lower_insn |= 0x1000U;
4114     }
4115
4116   // For a BLX instruction, make sure that the relocation is rounded up
4117   // to a word boundary.  This follows the semantics of the instruction
4118   // which specifies that bit 1 of the target address will come from bit
4119   // 1 of the base address.
4120   if ((lower_insn & 0x5000U) == 0x4000U)
4121     gold_assert((branch_offset & 3) == 0);
4122
4123   // Put BRANCH_OFFSET back into the insn.  Assumes two's complement.
4124   // We use the Thumb-2 encoding, which is safe even if dealing with
4125   // a Thumb-1 instruction by virtue of our overflow check above.  */
4126   upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4127   lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4128
4129   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4130   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4131
4132   gold_assert(!Bits<25>::has_overflow32(branch_offset));
4133
4134   return ((thumb2
4135            ? Bits<25>::has_overflow32(branch_offset)
4136            : Bits<23>::has_overflow32(branch_offset))
4137           ? This::STATUS_OVERFLOW
4138           : This::STATUS_OKAY);
4139 }
4140
4141 // Relocate THUMB-2 long conditional branches.
4142 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
4143 // undefined and we do not use PLT in this relocation.  In such a case,
4144 // the branch is converted into an NOP.
4145
4146 template<bool big_endian>
4147 typename Arm_relocate_functions<big_endian>::Status
4148 Arm_relocate_functions<big_endian>::thm_jump19(
4149     unsigned char* view,
4150     const Arm_relobj<big_endian>* object,
4151     const Symbol_value<32>* psymval,
4152     Arm_address address,
4153     Arm_address thumb_bit)
4154 {
4155   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4156   Valtype* wv = reinterpret_cast<Valtype*>(view);
4157   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4158   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4159   int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4160
4161   Arm_address branch_target = psymval->value(object, addend);
4162   int32_t branch_offset = branch_target - address;
4163
4164   // ??? Should handle interworking?  GCC might someday try to
4165   // use this for tail calls.
4166   // FIXME: We do support thumb entry to PLT yet.
4167   if (thumb_bit == 0)
4168     {
4169       gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4170       return This::STATUS_BAD_RELOC;
4171     }
4172
4173   // Put RELOCATION back into the insn.
4174   upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4175   lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4176
4177   // Put the relocated value back in the object file:
4178   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4179   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4180
4181   return (Bits<21>::has_overflow32(branch_offset)
4182           ? This::STATUS_OVERFLOW
4183           : This::STATUS_OKAY);
4184 }
4185
4186 // Get the GOT section, creating it if necessary.
4187
4188 template<bool big_endian>
4189 Arm_output_data_got<big_endian>*
4190 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4191 {
4192   if (this->got_ == NULL)
4193     {
4194       gold_assert(symtab != NULL && layout != NULL);
4195
4196       // When using -z now, we can treat .got as a relro section.
4197       // Without -z now, it is modified after program startup by lazy
4198       // PLT relocations.
4199       bool is_got_relro = parameters->options().now();
4200       Output_section_order got_order = (is_got_relro
4201                                         ? ORDER_RELRO_LAST
4202                                         : ORDER_DATA);
4203
4204       // Unlike some targets (.e.g x86), ARM does not use separate .got and
4205       // .got.plt sections in output.  The output .got section contains both
4206       // PLT and non-PLT GOT entries.
4207       this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4208
4209       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4210                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4211                                       this->got_, got_order, is_got_relro);
4212
4213       // The old GNU linker creates a .got.plt section.  We just
4214       // create another set of data in the .got section.  Note that we
4215       // always create a PLT if we create a GOT, although the PLT
4216       // might be empty.
4217       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4218       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4219                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4220                                       this->got_plt_, got_order, is_got_relro);
4221
4222       // The first three entries are reserved.
4223       this->got_plt_->set_current_data_size(3 * 4);
4224
4225       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4226       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4227                                     Symbol_table::PREDEFINED,
4228                                     this->got_plt_,
4229                                     0, 0, elfcpp::STT_OBJECT,
4230                                     elfcpp::STB_LOCAL,
4231                                     elfcpp::STV_HIDDEN, 0,
4232                                     false, false);
4233     }
4234   return this->got_;
4235 }
4236
4237 // Get the dynamic reloc section, creating it if necessary.
4238
4239 template<bool big_endian>
4240 typename Target_arm<big_endian>::Reloc_section*
4241 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4242 {
4243   if (this->rel_dyn_ == NULL)
4244     {
4245       gold_assert(layout != NULL);
4246       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4247       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4248                                       elfcpp::SHF_ALLOC, this->rel_dyn_,
4249                                       ORDER_DYNAMIC_RELOCS, false);
4250     }
4251   return this->rel_dyn_;
4252 }
4253
4254 // Insn_template methods.
4255
4256 // Return byte size of an instruction template.
4257
4258 size_t
4259 Insn_template::size() const
4260 {
4261   switch (this->type())
4262     {
4263     case THUMB16_TYPE:
4264     case THUMB16_SPECIAL_TYPE:
4265       return 2;
4266     case ARM_TYPE:
4267     case THUMB32_TYPE:
4268     case DATA_TYPE:
4269       return 4;
4270     default:
4271       gold_unreachable();
4272     }
4273 }
4274
4275 // Return alignment of an instruction template.
4276
4277 unsigned
4278 Insn_template::alignment() const
4279 {
4280   switch (this->type())
4281     {
4282     case THUMB16_TYPE:
4283     case THUMB16_SPECIAL_TYPE:
4284     case THUMB32_TYPE:
4285       return 2;
4286     case ARM_TYPE:
4287     case DATA_TYPE:
4288       return 4;
4289     default:
4290       gold_unreachable();
4291     }
4292 }
4293
4294 // Stub_template methods.
4295
4296 Stub_template::Stub_template(
4297     Stub_type type, const Insn_template* insns,
4298      size_t insn_count)
4299   : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4300     entry_in_thumb_mode_(false), relocs_()
4301 {
4302   off_t offset = 0;
4303
4304   // Compute byte size and alignment of stub template.
4305   for (size_t i = 0; i < insn_count; i++)
4306     {
4307       unsigned insn_alignment = insns[i].alignment();
4308       size_t insn_size = insns[i].size();
4309       gold_assert((offset & (insn_alignment - 1)) == 0);
4310       this->alignment_ = std::max(this->alignment_, insn_alignment);
4311       switch (insns[i].type())
4312         {
4313         case Insn_template::THUMB16_TYPE:
4314         case Insn_template::THUMB16_SPECIAL_TYPE:
4315           if (i == 0)
4316             this->entry_in_thumb_mode_ = true;
4317           break;
4318
4319         case Insn_template::THUMB32_TYPE:
4320           if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4321             this->relocs_.push_back(Reloc(i, offset));
4322           if (i == 0)
4323             this->entry_in_thumb_mode_ = true;
4324           break;
4325
4326         case Insn_template::ARM_TYPE:
4327           // Handle cases where the target is encoded within the
4328           // instruction.
4329           if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4330             this->relocs_.push_back(Reloc(i, offset));
4331           break;
4332
4333         case Insn_template::DATA_TYPE:
4334           // Entry point cannot be data.
4335           gold_assert(i != 0);
4336           this->relocs_.push_back(Reloc(i, offset));
4337           break;
4338
4339         default:
4340           gold_unreachable();
4341         }
4342       offset += insn_size;
4343     }
4344   this->size_ = offset;
4345 }
4346
4347 // Stub methods.
4348
4349 // Template to implement do_write for a specific target endianness.
4350
4351 template<bool big_endian>
4352 void inline
4353 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4354 {
4355   const Stub_template* stub_template = this->stub_template();
4356   const Insn_template* insns = stub_template->insns();
4357
4358   // FIXME:  We do not handle BE8 encoding yet.
4359   unsigned char* pov = view;
4360   for (size_t i = 0; i < stub_template->insn_count(); i++)
4361     {
4362       switch (insns[i].type())
4363         {
4364         case Insn_template::THUMB16_TYPE:
4365           elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4366           break;
4367         case Insn_template::THUMB16_SPECIAL_TYPE:
4368           elfcpp::Swap<16, big_endian>::writeval(
4369               pov,
4370               this->thumb16_special(i));
4371           break;
4372         case Insn_template::THUMB32_TYPE:
4373           {
4374             uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4375             uint32_t lo = insns[i].data() & 0xffff;
4376             elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4377             elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4378           }
4379           break;
4380         case Insn_template::ARM_TYPE:
4381         case Insn_template::DATA_TYPE:
4382           elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4383           break;
4384         default:
4385           gold_unreachable();
4386         }
4387       pov += insns[i].size();
4388     }
4389   gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4390 }
4391
4392 // Reloc_stub::Key methods.
4393
4394 // Dump a Key as a string for debugging.
4395
4396 std::string
4397 Reloc_stub::Key::name() const
4398 {
4399   if (this->r_sym_ == invalid_index)
4400     {
4401       // Global symbol key name
4402       // <stub-type>:<symbol name>:<addend>.
4403       const std::string sym_name = this->u_.symbol->name();
4404       // We need to print two hex number and two colons.  So just add 100 bytes
4405       // to the symbol name size.
4406       size_t len = sym_name.size() + 100;
4407       char* buffer = new char[len];
4408       int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4409                        sym_name.c_str(), this->addend_);
4410       gold_assert(c > 0 && c < static_cast<int>(len));
4411       delete[] buffer;
4412       return std::string(buffer);
4413     }
4414   else
4415     {
4416       // local symbol key name
4417       // <stub-type>:<object>:<r_sym>:<addend>.
4418       const size_t len = 200;
4419       char buffer[len];
4420       int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4421                        this->u_.relobj, this->r_sym_, this->addend_);
4422       gold_assert(c > 0 && c < static_cast<int>(len));
4423       return std::string(buffer);
4424     }
4425 }
4426
4427 // Reloc_stub methods.
4428
4429 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4430 // LOCATION to DESTINATION.
4431 // This code is based on the arm_type_of_stub function in
4432 // bfd/elf32-arm.c.  We have changed the interface a little to keep the Stub
4433 // class simple.
4434
4435 Stub_type
4436 Reloc_stub::stub_type_for_reloc(
4437    unsigned int r_type,
4438    Arm_address location,
4439    Arm_address destination,
4440    bool target_is_thumb)
4441 {
4442   Stub_type stub_type = arm_stub_none;
4443
4444   // This is a bit ugly but we want to avoid using a templated class for
4445   // big and little endianities.
4446   bool may_use_blx;
4447   bool should_force_pic_veneer;
4448   bool thumb2;
4449   bool thumb_only;
4450   if (parameters->target().is_big_endian())
4451     {
4452       const Target_arm<true>* big_endian_target =
4453         Target_arm<true>::default_target();
4454       may_use_blx = big_endian_target->may_use_v5t_interworking();
4455       should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4456       thumb2 = big_endian_target->using_thumb2();
4457       thumb_only = big_endian_target->using_thumb_only();
4458     }
4459   else
4460     {
4461       const Target_arm<false>* little_endian_target =
4462         Target_arm<false>::default_target();
4463       may_use_blx = little_endian_target->may_use_v5t_interworking();
4464       should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4465       thumb2 = little_endian_target->using_thumb2();
4466       thumb_only = little_endian_target->using_thumb_only();
4467     }
4468
4469   int64_t branch_offset;
4470   bool output_is_position_independent =
4471       parameters->options().output_is_position_independent();
4472   if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4473     {
4474       // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4475       // base address (instruction address + 4).
4476       if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4477         destination = Bits<32>::bit_select32(destination, location, 0x2);
4478       branch_offset = static_cast<int64_t>(destination) - location;
4479
4480       // Handle cases where:
4481       // - this call goes too far (different Thumb/Thumb2 max
4482       //   distance)
4483       // - it's a Thumb->Arm call and blx is not available, or it's a
4484       //   Thumb->Arm branch (not bl). A stub is needed in this case.
4485       if ((!thumb2
4486             && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4487                 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4488           || (thumb2
4489               && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4490                   || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4491           || ((!target_is_thumb)
4492               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4493                   || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4494         {
4495           if (target_is_thumb)
4496             {
4497               // Thumb to thumb.
4498               if (!thumb_only)
4499                 {
4500                   stub_type = (output_is_position_independent
4501                                || should_force_pic_veneer)
4502                     // PIC stubs.
4503                     ? ((may_use_blx
4504                         && (r_type == elfcpp::R_ARM_THM_CALL))
4505                        // V5T and above. Stub starts with ARM code, so
4506                        // we must be able to switch mode before
4507                        // reaching it, which is only possible for 'bl'
4508                        // (ie R_ARM_THM_CALL relocation).
4509                        ? arm_stub_long_branch_any_thumb_pic
4510                        // On V4T, use Thumb code only.
4511                        : arm_stub_long_branch_v4t_thumb_thumb_pic)
4512
4513                     // non-PIC stubs.
4514                     : ((may_use_blx
4515                         && (r_type == elfcpp::R_ARM_THM_CALL))
4516                        ? arm_stub_long_branch_any_any // V5T and above.
4517                        : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4518                 }
4519               else
4520                 {
4521                   stub_type = (output_is_position_independent
4522                                || should_force_pic_veneer)
4523                     ? arm_stub_long_branch_thumb_only_pic       // PIC stub.
4524                     : arm_stub_long_branch_thumb_only;  // non-PIC stub.
4525                 }
4526             }
4527           else
4528             {
4529               // Thumb to arm.
4530
4531               // FIXME: We should check that the input section is from an
4532               // object that has interwork enabled.
4533
4534               stub_type = (output_is_position_independent
4535                            || should_force_pic_veneer)
4536                 // PIC stubs.
4537                 ? ((may_use_blx
4538                     && (r_type == elfcpp::R_ARM_THM_CALL))
4539                    ? arm_stub_long_branch_any_arm_pic   // V5T and above.
4540                    : arm_stub_long_branch_v4t_thumb_arm_pic)    // V4T.
4541
4542                 // non-PIC stubs.
4543                 : ((may_use_blx
4544                     && (r_type == elfcpp::R_ARM_THM_CALL))
4545                    ? arm_stub_long_branch_any_any       // V5T and above.
4546                    : arm_stub_long_branch_v4t_thumb_arm);       // V4T.
4547
4548               // Handle v4t short branches.
4549               if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4550                   && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4551                   && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4552                 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4553             }
4554         }
4555     }
4556   else if (r_type == elfcpp::R_ARM_CALL
4557            || r_type == elfcpp::R_ARM_JUMP24
4558            || r_type == elfcpp::R_ARM_PLT32)
4559     {
4560       branch_offset = static_cast<int64_t>(destination) - location;
4561       if (target_is_thumb)
4562         {
4563           // Arm to thumb.
4564
4565           // FIXME: We should check that the input section is from an
4566           // object that has interwork enabled.
4567
4568           // We have an extra 2-bytes reach because of
4569           // the mode change (bit 24 (H) of BLX encoding).
4570           if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4571               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4572               || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4573               || (r_type == elfcpp::R_ARM_JUMP24)
4574               || (r_type == elfcpp::R_ARM_PLT32))
4575             {
4576               stub_type = (output_is_position_independent
4577                            || should_force_pic_veneer)
4578                 // PIC stubs.
4579                 ? (may_use_blx
4580                    ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4581                    : arm_stub_long_branch_v4t_arm_thumb_pic)    // V4T stub.
4582
4583                 // non-PIC stubs.
4584                 : (may_use_blx
4585                    ? arm_stub_long_branch_any_any       // V5T and above.
4586                    : arm_stub_long_branch_v4t_arm_thumb);       // V4T.
4587             }
4588         }
4589       else
4590         {
4591           // Arm to arm.
4592           if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4593               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4594             {
4595               stub_type = (output_is_position_independent
4596                            || should_force_pic_veneer)
4597                 ? arm_stub_long_branch_any_arm_pic      // PIC stubs.
4598                 : arm_stub_long_branch_any_any;         /// non-PIC.
4599             }
4600         }
4601     }
4602
4603   return stub_type;
4604 }
4605
4606 // Cortex_a8_stub methods.
4607
4608 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4609 // I is the position of the instruction template in the stub template.
4610
4611 uint16_t
4612 Cortex_a8_stub::do_thumb16_special(size_t i)
4613 {
4614   // The only use of this is to copy condition code from a conditional
4615   // branch being worked around to the corresponding conditional branch in
4616   // to the stub.
4617   gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4618               && i == 0);
4619   uint16_t data = this->stub_template()->insns()[i].data();
4620   gold_assert((data & 0xff00U) == 0xd000U);
4621   data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4622   return data;
4623 }
4624
4625 // Stub_factory methods.
4626
4627 Stub_factory::Stub_factory()
4628 {
4629   // The instruction template sequences are declared as static
4630   // objects and initialized first time the constructor runs.
4631
4632   // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4633   // to reach the stub if necessary.
4634   static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4635     {
4636       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4637       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4638                                                 // dcd   R_ARM_ABS32(X)
4639     };
4640
4641   // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4642   // available.
4643   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4644     {
4645       Insn_template::arm_insn(0xe59fc000),      // ldr   ip, [pc, #0]
4646       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4647       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4648                                                 // dcd   R_ARM_ABS32(X)
4649     };
4650
4651   // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4652   static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4653     {
4654       Insn_template::thumb16_insn(0xb401),      // push {r0}
4655       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4656       Insn_template::thumb16_insn(0x4684),      // mov  ip, r0
4657       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4658       Insn_template::thumb16_insn(0x4760),      // bx   ip
4659       Insn_template::thumb16_insn(0xbf00),      // nop
4660       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4661                                                 // dcd  R_ARM_ABS32(X)
4662     };
4663
4664   // V4T Thumb -> Thumb long branch stub. Using the stack is not
4665   // allowed.
4666   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4667     {
4668       Insn_template::thumb16_insn(0x4778),      // bx   pc
4669       Insn_template::thumb16_insn(0x46c0),      // nop
4670       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4671       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4672       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4673                                                 // dcd  R_ARM_ABS32(X)
4674     };
4675
4676   // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4677   // available.
4678   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4679     {
4680       Insn_template::thumb16_insn(0x4778),      // bx   pc
4681       Insn_template::thumb16_insn(0x46c0),      // nop
4682       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4683       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4684                                                 // dcd   R_ARM_ABS32(X)
4685     };
4686
4687   // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4688   // one, when the destination is close enough.
4689   static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4690     {
4691       Insn_template::thumb16_insn(0x4778),              // bx   pc
4692       Insn_template::thumb16_insn(0x46c0),              // nop
4693       Insn_template::arm_rel_insn(0xea000000, -8),      // b    (X-8)
4694     };
4695
4696   // ARM/Thumb -> ARM long branch stub, PIC.  On V5T and above, use
4697   // blx to reach the stub if necessary.
4698   static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4699     {
4700       Insn_template::arm_insn(0xe59fc000),      // ldr   r12, [pc]
4701       Insn_template::arm_insn(0xe08ff00c),      // add   pc, pc, ip
4702       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4703                                                 // dcd   R_ARM_REL32(X-4)
4704     };
4705
4706   // ARM/Thumb -> Thumb long branch stub, PIC.  On V5T and above, use
4707   // blx to reach the stub if necessary.  We can not add into pc;
4708   // it is not guaranteed to mode switch (different in ARMv6 and
4709   // ARMv7).
4710   static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4711     {
4712       Insn_template::arm_insn(0xe59fc004),      // ldr   r12, [pc, #4]
4713       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4714       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4715       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4716                                                 // dcd   R_ARM_REL32(X)
4717     };
4718
4719   // V4T ARM -> ARM long branch stub, PIC.
4720   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4721     {
4722       Insn_template::arm_insn(0xe59fc004),      // ldr   ip, [pc, #4]
4723       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4724       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4725       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4726                                                 // dcd   R_ARM_REL32(X)
4727     };
4728
4729   // V4T Thumb -> ARM long branch stub, PIC.
4730   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4731     {
4732       Insn_template::thumb16_insn(0x4778),      // bx   pc
4733       Insn_template::thumb16_insn(0x46c0),      // nop
4734       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4735       Insn_template::arm_insn(0xe08cf00f),      // add  pc, ip, pc
4736       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4737                                                 // dcd  R_ARM_REL32(X)
4738     };
4739
4740   // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4741   // architectures.
4742   static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4743     {
4744       Insn_template::thumb16_insn(0xb401),      // push {r0}
4745       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4746       Insn_template::thumb16_insn(0x46fc),      // mov  ip, pc
4747       Insn_template::thumb16_insn(0x4484),      // add  ip, r0
4748       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4749       Insn_template::thumb16_insn(0x4760),      // bx   ip
4750       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4751                                                 // dcd  R_ARM_REL32(X)
4752     };
4753
4754   // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4755   // allowed.
4756   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4757     {
4758       Insn_template::thumb16_insn(0x4778),      // bx   pc
4759       Insn_template::thumb16_insn(0x46c0),      // nop
4760       Insn_template::arm_insn(0xe59fc004),      // ldr  ip, [pc, #4]
4761       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4762       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4763       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4764                                                 // dcd  R_ARM_REL32(X)
4765     };
4766
4767   // Cortex-A8 erratum-workaround stubs.
4768
4769   // Stub used for conditional branches (which may be beyond +/-1MB away,
4770   // so we can't use a conditional branch to reach this stub).
4771
4772   // original code:
4773   //
4774   //    b<cond> X
4775   // after:
4776   //
4777   static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4778     {
4779       Insn_template::thumb16_bcond_insn(0xd001),        //      b<cond>.n true
4780       Insn_template::thumb32_b_insn(0xf000b800, -4),    //      b.w after
4781       Insn_template::thumb32_b_insn(0xf000b800, -4)     // true:
4782                                                         //      b.w X
4783     };
4784
4785   // Stub used for b.w and bl.w instructions.
4786
4787   static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4788     {
4789       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4790     };
4791
4792   static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4793     {
4794       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4795     };
4796
4797   // Stub used for Thumb-2 blx.w instructions.  We modified the original blx.w
4798   // instruction (which switches to ARM mode) to point to this stub.  Jump to
4799   // the real destination using an ARM-mode branch.
4800   static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4801     {
4802       Insn_template::arm_rel_insn(0xea000000, -8)       // b dest
4803     };
4804
4805   // Stub used to provide an interworking for R_ARM_V4BX relocation
4806   // (bx r[n] instruction).
4807   static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4808     {
4809       Insn_template::arm_insn(0xe3100001),              // tst   r<n>, #1
4810       Insn_template::arm_insn(0x01a0f000),              // moveq pc, r<n>
4811       Insn_template::arm_insn(0xe12fff10)               // bx    r<n>
4812     };
4813
4814   // Fill in the stub template look-up table.  Stub templates are constructed
4815   // per instance of Stub_factory for fast look-up without locking
4816   // in a thread-enabled environment.
4817
4818   this->stub_templates_[arm_stub_none] =
4819     new Stub_template(arm_stub_none, NULL, 0);
4820
4821 #define DEF_STUB(x)     \
4822   do \
4823     { \
4824       size_t array_size \
4825         = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4826       Stub_type type = arm_stub_##x; \
4827       this->stub_templates_[type] = \
4828         new Stub_template(type, elf32_arm_stub_##x, array_size); \
4829     } \
4830   while (0);
4831
4832   DEF_STUBS
4833 #undef DEF_STUB
4834 }
4835
4836 // Stub_table methods.
4837
4838 // Remove all Cortex-A8 stub.
4839
4840 template<bool big_endian>
4841 void
4842 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4843 {
4844   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4845        p != this->cortex_a8_stubs_.end();
4846        ++p)
4847     delete p->second;
4848   this->cortex_a8_stubs_.clear();
4849 }
4850
4851 // Relocate one stub.  This is a helper for Stub_table::relocate_stubs().
4852
4853 template<bool big_endian>
4854 void
4855 Stub_table<big_endian>::relocate_stub(
4856     Stub* stub,
4857     const Relocate_info<32, big_endian>* relinfo,
4858     Target_arm<big_endian>* arm_target,
4859     Output_section* output_section,
4860     unsigned char* view,
4861     Arm_address address,
4862     section_size_type view_size)
4863 {
4864   const Stub_template* stub_template = stub->stub_template();
4865   if (stub_template->reloc_count() != 0)
4866     {
4867       // Adjust view to cover the stub only.
4868       section_size_type offset = stub->offset();
4869       section_size_type stub_size = stub_template->size();
4870       gold_assert(offset + stub_size <= view_size);
4871
4872       arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4873                                 address + offset, stub_size);
4874     }
4875 }
4876
4877 // Relocate all stubs in this stub table.
4878
4879 template<bool big_endian>
4880 void
4881 Stub_table<big_endian>::relocate_stubs(
4882     const Relocate_info<32, big_endian>* relinfo,
4883     Target_arm<big_endian>* arm_target,
4884     Output_section* output_section,
4885     unsigned char* view,
4886     Arm_address address,
4887     section_size_type view_size)
4888 {
4889   // If we are passed a view bigger than the stub table's.  we need to
4890   // adjust the view.
4891   gold_assert(address == this->address()
4892               && (view_size
4893                   == static_cast<section_size_type>(this->data_size())));
4894
4895   // Relocate all relocation stubs.
4896   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4897       p != this->reloc_stubs_.end();
4898       ++p)
4899     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4900                         address, view_size);
4901
4902   // Relocate all Cortex-A8 stubs.
4903   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4904        p != this->cortex_a8_stubs_.end();
4905        ++p)
4906     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4907                         address, view_size);
4908
4909   // Relocate all ARM V4BX stubs.
4910   for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4911        p != this->arm_v4bx_stubs_.end();
4912        ++p)
4913     {
4914       if (*p != NULL)
4915         this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4916                             address, view_size);
4917     }
4918 }
4919
4920 // Write out the stubs to file.
4921
4922 template<bool big_endian>
4923 void
4924 Stub_table<big_endian>::do_write(Output_file* of)
4925 {
4926   off_t offset = this->offset();
4927   const section_size_type oview_size =
4928     convert_to_section_size_type(this->data_size());
4929   unsigned char* const oview = of->get_output_view(offset, oview_size);
4930
4931   // Write relocation stubs.
4932   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4933       p != this->reloc_stubs_.end();
4934       ++p)
4935     {
4936       Reloc_stub* stub = p->second;
4937       Arm_address address = this->address() + stub->offset();
4938       gold_assert(address
4939                   == align_address(address,
4940                                    stub->stub_template()->alignment()));
4941       stub->write(oview + stub->offset(), stub->stub_template()->size(),
4942                   big_endian);
4943     }
4944
4945   // Write Cortex-A8 stubs.
4946   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4947        p != this->cortex_a8_stubs_.end();
4948        ++p)
4949     {
4950       Cortex_a8_stub* stub = p->second;
4951       Arm_address address = this->address() + stub->offset();
4952       gold_assert(address
4953                   == align_address(address,
4954                                    stub->stub_template()->alignment()));
4955       stub->write(oview + stub->offset(), stub->stub_template()->size(),
4956                   big_endian);
4957     }
4958
4959   // Write ARM V4BX relocation stubs.
4960   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4961        p != this->arm_v4bx_stubs_.end();
4962        ++p)
4963     {
4964       if (*p == NULL)
4965         continue;
4966
4967       Arm_address address = this->address() + (*p)->offset();
4968       gold_assert(address
4969                   == align_address(address,
4970                                    (*p)->stub_template()->alignment()));
4971       (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4972                   big_endian);
4973     }
4974
4975   of->write_output_view(this->offset(), oview_size, oview);
4976 }
4977
4978 // Update the data size and address alignment of the stub table at the end
4979 // of a relaxation pass.   Return true if either the data size or the
4980 // alignment changed in this relaxation pass.
4981
4982 template<bool big_endian>
4983 bool
4984 Stub_table<big_endian>::update_data_size_and_addralign()
4985 {
4986   // Go over all stubs in table to compute data size and address alignment.
4987   off_t size = this->reloc_stubs_size_;
4988   unsigned addralign = this->reloc_stubs_addralign_;
4989
4990   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4991        p != this->cortex_a8_stubs_.end();
4992        ++p)
4993     {
4994       const Stub_template* stub_template = p->second->stub_template();
4995       addralign = std::max(addralign, stub_template->alignment());
4996       size = (align_address(size, stub_template->alignment())
4997               + stub_template->size());
4998     }
4999
5000   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5001        p != this->arm_v4bx_stubs_.end();
5002        ++p)
5003     {
5004       if (*p == NULL)
5005         continue;
5006
5007       const Stub_template* stub_template = (*p)->stub_template();
5008       addralign = std::max(addralign, stub_template->alignment());
5009       size = (align_address(size, stub_template->alignment())
5010               + stub_template->size());
5011     }
5012
5013   // Check if either data size or alignment changed in this pass.
5014   // Update prev_data_size_ and prev_addralign_.  These will be used
5015   // as the current data size and address alignment for the next pass.
5016   bool changed = size != this->prev_data_size_;
5017   this->prev_data_size_ = size;
5018
5019   if (addralign != this->prev_addralign_)
5020     changed = true;
5021   this->prev_addralign_ = addralign;
5022
5023   return changed;
5024 }
5025
5026 // Finalize the stubs.  This sets the offsets of the stubs within the stub
5027 // table.  It also marks all input sections needing Cortex-A8 workaround.
5028
5029 template<bool big_endian>
5030 void
5031 Stub_table<big_endian>::finalize_stubs()
5032 {
5033   off_t off = this->reloc_stubs_size_;
5034   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5035        p != this->cortex_a8_stubs_.end();
5036        ++p)
5037     {
5038       Cortex_a8_stub* stub = p->second;
5039       const Stub_template* stub_template = stub->stub_template();
5040       uint64_t stub_addralign = stub_template->alignment();
5041       off = align_address(off, stub_addralign);
5042       stub->set_offset(off);
5043       off += stub_template->size();
5044
5045       // Mark input section so that we can determine later if a code section
5046       // needs the Cortex-A8 workaround quickly.
5047       Arm_relobj<big_endian>* arm_relobj =
5048         Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5049       arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5050     }
5051
5052   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5053       p != this->arm_v4bx_stubs_.end();
5054       ++p)
5055     {
5056       if (*p == NULL)
5057         continue;
5058
5059       const Stub_template* stub_template = (*p)->stub_template();
5060       uint64_t stub_addralign = stub_template->alignment();
5061       off = align_address(off, stub_addralign);
5062       (*p)->set_offset(off);
5063       off += stub_template->size();
5064     }
5065
5066   gold_assert(off <= this->prev_data_size_);
5067 }
5068
5069 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5070 // and VIEW_ADDRESS + VIEW_SIZE - 1.  VIEW points to the mapped address
5071 // of the address range seen by the linker.
5072
5073 template<bool big_endian>
5074 void
5075 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5076     Target_arm<big_endian>* arm_target,
5077     unsigned char* view,
5078     Arm_address view_address,
5079     section_size_type view_size)
5080 {
5081   // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5082   for (Cortex_a8_stub_list::const_iterator p =
5083          this->cortex_a8_stubs_.lower_bound(view_address);
5084        ((p != this->cortex_a8_stubs_.end())
5085         && (p->first < (view_address + view_size)));
5086        ++p)
5087     {
5088       // We do not store the THUMB bit in the LSB of either the branch address
5089       // or the stub offset.  There is no need to strip the LSB.
5090       Arm_address branch_address = p->first;
5091       const Cortex_a8_stub* stub = p->second;
5092       Arm_address stub_address = this->address() + stub->offset();
5093
5094       // Offset of the branch instruction relative to this view.
5095       section_size_type offset =
5096         convert_to_section_size_type(branch_address - view_address);
5097       gold_assert((offset + 4) <= view_size);
5098
5099       arm_target->apply_cortex_a8_workaround(stub, stub_address,
5100                                              view + offset, branch_address);
5101     }
5102 }
5103
5104 // Arm_input_section methods.
5105
5106 // Initialize an Arm_input_section.
5107
5108 template<bool big_endian>
5109 void
5110 Arm_input_section<big_endian>::init()
5111 {
5112   Relobj* relobj = this->relobj();
5113   unsigned int shndx = this->shndx();
5114
5115   // We have to cache original size, alignment and contents to avoid locking
5116   // the original file.
5117   this->original_addralign_ =
5118     convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5119
5120   // This is not efficient but we expect only a small number of relaxed
5121   // input sections for stubs.
5122   section_size_type section_size;
5123   const unsigned char* section_contents =
5124     relobj->section_contents(shndx, &section_size, false);
5125   this->original_size_ =
5126     convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5127
5128   gold_assert(this->original_contents_ == NULL);
5129   this->original_contents_ = new unsigned char[section_size];
5130   memcpy(this->original_contents_, section_contents, section_size);
5131
5132   // We want to make this look like the original input section after
5133   // output sections are finalized.
5134   Output_section* os = relobj->output_section(shndx);
5135   off_t offset = relobj->output_section_offset(shndx);
5136   gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5137   this->set_address(os->address() + offset);
5138   this->set_file_offset(os->offset() + offset);
5139
5140   this->set_current_data_size(this->original_size_);
5141   this->finalize_data_size();
5142 }
5143
5144 template<bool big_endian>
5145 void
5146 Arm_input_section<big_endian>::do_write(Output_file* of)
5147 {
5148   // We have to write out the original section content.
5149   gold_assert(this->original_contents_ != NULL);
5150   of->write(this->offset(), this->original_contents_,
5151             this->original_size_);
5152
5153   // If this owns a stub table and it is not empty, write it.
5154   if (this->is_stub_table_owner() && !this->stub_table_->empty())
5155     this->stub_table_->write(of);
5156 }
5157
5158 // Finalize data size.
5159
5160 template<bool big_endian>
5161 void
5162 Arm_input_section<big_endian>::set_final_data_size()
5163 {
5164   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5165
5166   if (this->is_stub_table_owner())
5167     {
5168       this->stub_table_->finalize_data_size();
5169       off = align_address(off, this->stub_table_->addralign());
5170       off += this->stub_table_->data_size();
5171     }
5172   this->set_data_size(off);
5173 }
5174
5175 // Reset address and file offset.
5176
5177 template<bool big_endian>
5178 void
5179 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5180 {
5181   // Size of the original input section contents.
5182   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5183
5184   // If this is a stub table owner, account for the stub table size.
5185   if (this->is_stub_table_owner())
5186     {
5187       Stub_table<big_endian>* stub_table = this->stub_table_;
5188
5189       // Reset the stub table's address and file offset.  The
5190       // current data size for child will be updated after that.
5191       stub_table_->reset_address_and_file_offset();
5192       off = align_address(off, stub_table_->addralign());
5193       off += stub_table->current_data_size();
5194     }
5195
5196   this->set_current_data_size(off);
5197 }
5198
5199 // Arm_exidx_cantunwind methods.
5200
5201 // Write this to Output file OF for a fixed endianness.
5202
5203 template<bool big_endian>
5204 void
5205 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5206 {
5207   off_t offset = this->offset();
5208   const section_size_type oview_size = 8;
5209   unsigned char* const oview = of->get_output_view(offset, oview_size);
5210
5211   Output_section* os = this->relobj_->output_section(this->shndx_);
5212   gold_assert(os != NULL);
5213
5214   Arm_relobj<big_endian>* arm_relobj =
5215     Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5216   Arm_address output_offset =
5217     arm_relobj->get_output_section_offset(this->shndx_);
5218   Arm_address section_start;
5219   section_size_type section_size;
5220
5221   // Find out the end of the text section referred by this.
5222   if (output_offset != Arm_relobj<big_endian>::invalid_address)
5223     {
5224       section_start = os->address() + output_offset;
5225       const Arm_exidx_input_section* exidx_input_section =
5226         arm_relobj->exidx_input_section_by_link(this->shndx_);
5227       gold_assert(exidx_input_section != NULL);
5228       section_size =
5229         convert_to_section_size_type(exidx_input_section->text_size());
5230     }
5231   else
5232     {
5233       // Currently this only happens for a relaxed section.
5234       const Output_relaxed_input_section* poris =
5235         os->find_relaxed_input_section(this->relobj_, this->shndx_);
5236       gold_assert(poris != NULL);
5237       section_start = poris->address();
5238       section_size = convert_to_section_size_type(poris->data_size());
5239     }
5240
5241   // We always append this to the end of an EXIDX section.
5242   Arm_address output_address = section_start + section_size;
5243
5244   // Write out the entry.  The first word either points to the beginning
5245   // or after the end of a text section.  The second word is the special
5246   // EXIDX_CANTUNWIND value.
5247   uint32_t prel31_offset = output_address - this->address();
5248   if (Bits<31>::has_overflow32(offset))
5249     gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5250   elfcpp::Swap_unaligned<32, big_endian>::writeval(oview,
5251                                                    prel31_offset & 0x7fffffffU);
5252   elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4,
5253                                                    elfcpp::EXIDX_CANTUNWIND);
5254
5255   of->write_output_view(this->offset(), oview_size, oview);
5256 }
5257
5258 // Arm_exidx_merged_section methods.
5259
5260 // Constructor for Arm_exidx_merged_section.
5261 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5262 // SECTION_OFFSET_MAP points to a section offset map describing how
5263 // parts of the input section are mapped to output.  DELETED_BYTES is
5264 // the number of bytes deleted from the EXIDX input section.
5265
5266 Arm_exidx_merged_section::Arm_exidx_merged_section(
5267     const Arm_exidx_input_section& exidx_input_section,
5268     const Arm_exidx_section_offset_map& section_offset_map,
5269     uint32_t deleted_bytes)
5270   : Output_relaxed_input_section(exidx_input_section.relobj(),
5271                                  exidx_input_section.shndx(),
5272                                  exidx_input_section.addralign()),
5273     exidx_input_section_(exidx_input_section),
5274     section_offset_map_(section_offset_map)
5275 {
5276   // If we retain or discard the whole EXIDX input section,  we would
5277   // not be here.
5278   gold_assert(deleted_bytes != 0
5279               && deleted_bytes != this->exidx_input_section_.size());
5280
5281   // Fix size here so that we do not need to implement set_final_data_size.
5282   uint32_t size = exidx_input_section.size() - deleted_bytes;
5283   this->set_data_size(size);
5284   this->fix_data_size();
5285
5286   // Allocate buffer for section contents and build contents.
5287   this->section_contents_ = new unsigned char[size];
5288 }
5289
5290 // Build the contents of a merged EXIDX output section.
5291
5292 void
5293 Arm_exidx_merged_section::build_contents(
5294     const unsigned char* original_contents,
5295     section_size_type original_size)
5296 {
5297   // Go over spans of input offsets and write only those that are not
5298   // discarded.
5299   section_offset_type in_start = 0;
5300   section_offset_type out_start = 0;
5301   section_offset_type in_max =
5302     convert_types<section_offset_type>(original_size);
5303   section_offset_type out_max =
5304     convert_types<section_offset_type>(this->data_size());
5305   for (Arm_exidx_section_offset_map::const_iterator p =
5306         this->section_offset_map_.begin();
5307       p != this->section_offset_map_.end();
5308       ++p)
5309     {
5310       section_offset_type in_end = p->first;
5311       gold_assert(in_end >= in_start);
5312       section_offset_type out_end = p->second;
5313       size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5314       if (out_end != -1)
5315         {
5316           size_t out_chunk_size =
5317             convert_types<size_t>(out_end - out_start + 1);
5318
5319           gold_assert(out_chunk_size == in_chunk_size
5320                       && in_end < in_max && out_end < out_max);
5321
5322           memcpy(this->section_contents_ + out_start,
5323                  original_contents + in_start,
5324                  out_chunk_size);
5325           out_start += out_chunk_size;
5326         }
5327       in_start += in_chunk_size;
5328     }
5329 }
5330
5331 // Given an input OBJECT, an input section index SHNDX within that
5332 // object, and an OFFSET relative to the start of that input
5333 // section, return whether or not the corresponding offset within
5334 // the output section is known.  If this function returns true, it
5335 // sets *POUTPUT to the output offset.  The value -1 indicates that
5336 // this input offset is being discarded.
5337
5338 bool
5339 Arm_exidx_merged_section::do_output_offset(
5340     const Relobj* relobj,
5341     unsigned int shndx,
5342     section_offset_type offset,
5343     section_offset_type* poutput) const
5344 {
5345   // We only handle offsets for the original EXIDX input section.
5346   if (relobj != this->exidx_input_section_.relobj()
5347       || shndx != this->exidx_input_section_.shndx())
5348     return false;
5349
5350   section_offset_type section_size =
5351     convert_types<section_offset_type>(this->exidx_input_section_.size());
5352   if (offset < 0 || offset >= section_size)
5353     // Input offset is out of valid range.
5354     *poutput = -1;
5355   else
5356     {
5357       // We need to look up the section offset map to determine the output
5358       // offset.  Find the reference point in map that is first offset
5359       // bigger than or equal to this offset.
5360       Arm_exidx_section_offset_map::const_iterator p =
5361         this->section_offset_map_.lower_bound(offset);
5362
5363       // The section offset maps are build such that this should not happen if
5364       // input offset is in the valid range.
5365       gold_assert(p != this->section_offset_map_.end());
5366
5367       // We need to check if this is dropped.
5368      section_offset_type ref = p->first;
5369      section_offset_type mapped_ref = p->second;
5370
5371       if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5372         // Offset is present in output.
5373         *poutput = mapped_ref + (offset - ref);
5374       else
5375         // Offset is discarded owing to EXIDX entry merging.
5376         *poutput = -1;
5377     }
5378
5379   return true;
5380 }
5381
5382 // Write this to output file OF.
5383
5384 void
5385 Arm_exidx_merged_section::do_write(Output_file* of)
5386 {
5387   off_t offset = this->offset();
5388   const section_size_type oview_size = this->data_size();
5389   unsigned char* const oview = of->get_output_view(offset, oview_size);
5390
5391   Output_section* os = this->relobj()->output_section(this->shndx());
5392   gold_assert(os != NULL);
5393
5394   memcpy(oview, this->section_contents_, oview_size);
5395   of->write_output_view(this->offset(), oview_size, oview);
5396 }
5397
5398 // Arm_exidx_fixup methods.
5399
5400 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5401 // is not an EXIDX_CANTUNWIND entry already.  The new EXIDX_CANTUNWIND entry
5402 // points to the end of the last seen EXIDX section.
5403
5404 void
5405 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5406 {
5407   if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5408       && this->last_input_section_ != NULL)
5409     {
5410       Relobj* relobj = this->last_input_section_->relobj();
5411       unsigned int text_shndx = this->last_input_section_->link();
5412       Arm_exidx_cantunwind* cantunwind =
5413         new Arm_exidx_cantunwind(relobj, text_shndx);
5414       this->exidx_output_section_->add_output_section_data(cantunwind);
5415       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5416     }
5417 }
5418
5419 // Process an EXIDX section entry in input.  Return whether this entry
5420 // can be deleted in the output.  SECOND_WORD in the second word of the
5421 // EXIDX entry.
5422
5423 bool
5424 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5425 {
5426   bool delete_entry;
5427   if (second_word == elfcpp::EXIDX_CANTUNWIND)
5428     {
5429       // Merge if previous entry is also an EXIDX_CANTUNWIND.
5430       delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5431       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5432     }
5433   else if ((second_word & 0x80000000) != 0)
5434     {
5435       // Inlined unwinding data.  Merge if equal to previous.
5436       delete_entry = (merge_exidx_entries_
5437                       && this->last_unwind_type_ == UT_INLINED_ENTRY
5438                       && this->last_inlined_entry_ == second_word);
5439       this->last_unwind_type_ = UT_INLINED_ENTRY;
5440       this->last_inlined_entry_ = second_word;
5441     }
5442   else
5443     {
5444       // Normal table entry.  In theory we could merge these too,
5445       // but duplicate entries are likely to be much less common.
5446       delete_entry = false;
5447       this->last_unwind_type_ = UT_NORMAL_ENTRY;
5448     }
5449   return delete_entry;
5450 }
5451
5452 // Update the current section offset map during EXIDX section fix-up.
5453 // If there is no map, create one.  INPUT_OFFSET is the offset of a
5454 // reference point, DELETED_BYTES is the number of deleted by in the
5455 // section so far.  If DELETE_ENTRY is true, the reference point and
5456 // all offsets after the previous reference point are discarded.
5457
5458 void
5459 Arm_exidx_fixup::update_offset_map(
5460     section_offset_type input_offset,
5461     section_size_type deleted_bytes,
5462     bool delete_entry)
5463 {
5464   if (this->section_offset_map_ == NULL)
5465     this->section_offset_map_ = new Arm_exidx_section_offset_map();
5466   section_offset_type output_offset;
5467   if (delete_entry)
5468     output_offset = Arm_exidx_input_section::invalid_offset;
5469   else
5470     output_offset = input_offset - deleted_bytes;
5471   (*this->section_offset_map_)[input_offset] = output_offset;
5472 }
5473
5474 // Process EXIDX_INPUT_SECTION for EXIDX entry merging.  Return the number of
5475 // bytes deleted.  SECTION_CONTENTS points to the contents of the EXIDX
5476 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5477 // If some entries are merged, also store a pointer to a newly created
5478 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP.  The caller
5479 // owns the map and is responsible for releasing it after use.
5480
5481 template<bool big_endian>
5482 uint32_t
5483 Arm_exidx_fixup::process_exidx_section(
5484     const Arm_exidx_input_section* exidx_input_section,
5485     const unsigned char* section_contents,
5486     section_size_type section_size,
5487     Arm_exidx_section_offset_map** psection_offset_map)
5488 {
5489   Relobj* relobj = exidx_input_section->relobj();
5490   unsigned shndx = exidx_input_section->shndx();
5491
5492   if ((section_size % 8) != 0)
5493     {
5494       // Something is wrong with this section.  Better not touch it.
5495       gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5496                  relobj->name().c_str(), shndx);
5497       this->last_input_section_ = exidx_input_section;
5498       this->last_unwind_type_ = UT_NONE;
5499       return 0;
5500     }
5501
5502   uint32_t deleted_bytes = 0;
5503   bool prev_delete_entry = false;
5504   gold_assert(this->section_offset_map_ == NULL);
5505
5506   for (section_size_type i = 0; i < section_size; i += 8)
5507     {
5508       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5509       const Valtype* wv =
5510           reinterpret_cast<const Valtype*>(section_contents + i + 4);
5511       uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5512
5513       bool delete_entry = this->process_exidx_entry(second_word);
5514
5515       // Entry deletion causes changes in output offsets.  We use a std::map
5516       // to record these.  And entry (x, y) means input offset x
5517       // is mapped to output offset y.  If y is invalid_offset, then x is
5518       // dropped in the output.  Because of the way std::map::lower_bound
5519       // works, we record the last offset in a region w.r.t to keeping or
5520       // dropping.  If there is no entry (x0, y0) for an input offset x0,
5521       // the output offset y0 of it is determined by the output offset y1 of
5522       // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5523       // in the map.  If y1 is not -1, then y0 = y1 + x0 - x1.  Otherwise, y1
5524       // y0 is also -1.
5525       if (delete_entry != prev_delete_entry && i != 0)
5526         this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5527
5528       // Update total deleted bytes for this entry.
5529       if (delete_entry)
5530         deleted_bytes += 8;
5531
5532       prev_delete_entry = delete_entry;
5533     }
5534
5535   // If section offset map is not NULL, make an entry for the end of
5536   // section.
5537   if (this->section_offset_map_ != NULL)
5538     update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5539
5540   *psection_offset_map = this->section_offset_map_;
5541   this->section_offset_map_ = NULL;
5542   this->last_input_section_ = exidx_input_section;
5543
5544   // Set the first output text section so that we can link the EXIDX output
5545   // section to it.  Ignore any EXIDX input section that is completely merged.
5546   if (this->first_output_text_section_ == NULL
5547       && deleted_bytes != section_size)
5548     {
5549       unsigned int link = exidx_input_section->link();
5550       Output_section* os = relobj->output_section(link);
5551       gold_assert(os != NULL);
5552       this->first_output_text_section_ = os;
5553     }
5554
5555   return deleted_bytes;
5556 }
5557
5558 // Arm_output_section methods.
5559
5560 // Create a stub group for input sections from BEGIN to END.  OWNER
5561 // points to the input section to be the owner a new stub table.
5562
5563 template<bool big_endian>
5564 void
5565 Arm_output_section<big_endian>::create_stub_group(
5566   Input_section_list::const_iterator begin,
5567   Input_section_list::const_iterator end,
5568   Input_section_list::const_iterator owner,
5569   Target_arm<big_endian>* target,
5570   std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5571   const Task* task)
5572 {
5573   // We use a different kind of relaxed section in an EXIDX section.
5574   // The static casting from Output_relaxed_input_section to
5575   // Arm_input_section is invalid in an EXIDX section.  We are okay
5576   // because we should not be calling this for an EXIDX section.
5577   gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5578
5579   // Currently we convert ordinary input sections into relaxed sections only
5580   // at this point but we may want to support creating relaxed input section
5581   // very early.  So we check here to see if owner is already a relaxed
5582   // section.
5583
5584   Arm_input_section<big_endian>* arm_input_section;
5585   if (owner->is_relaxed_input_section())
5586     {
5587       arm_input_section =
5588         Arm_input_section<big_endian>::as_arm_input_section(
5589           owner->relaxed_input_section());
5590     }
5591   else
5592     {
5593       gold_assert(owner->is_input_section());
5594       // Create a new relaxed input section.  We need to lock the original
5595       // file.
5596       Task_lock_obj<Object> tl(task, owner->relobj());
5597       arm_input_section =
5598         target->new_arm_input_section(owner->relobj(), owner->shndx());
5599       new_relaxed_sections->push_back(arm_input_section);
5600     }
5601
5602   // Create a stub table.
5603   Stub_table<big_endian>* stub_table =
5604     target->new_stub_table(arm_input_section);
5605
5606   arm_input_section->set_stub_table(stub_table);
5607
5608   Input_section_list::const_iterator p = begin;
5609   Input_section_list::const_iterator prev_p;
5610
5611   // Look for input sections or relaxed input sections in [begin ... end].
5612   do
5613     {
5614       if (p->is_input_section() || p->is_relaxed_input_section())
5615         {
5616           // The stub table information for input sections live
5617           // in their objects.
5618           Arm_relobj<big_endian>* arm_relobj =
5619             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5620           arm_relobj->set_stub_table(p->shndx(), stub_table);
5621         }
5622       prev_p = p++;
5623     }
5624   while (prev_p != end);
5625 }
5626
5627 // Group input sections for stub generation.  GROUP_SIZE is roughly the limit
5628 // of stub groups.  We grow a stub group by adding input section until the
5629 // size is just below GROUP_SIZE.  The last input section will be converted
5630 // into a stub table.  If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5631 // input section after the stub table, effectively double the group size.
5632 //
5633 // This is similar to the group_sections() function in elf32-arm.c but is
5634 // implemented differently.
5635
5636 template<bool big_endian>
5637 void
5638 Arm_output_section<big_endian>::group_sections(
5639     section_size_type group_size,
5640     bool stubs_always_after_branch,
5641     Target_arm<big_endian>* target,
5642     const Task* task)
5643 {
5644   // We only care about sections containing code.
5645   if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
5646     return;
5647
5648   // States for grouping.
5649   typedef enum
5650   {
5651     // No group is being built.
5652     NO_GROUP,
5653     // A group is being built but the stub table is not found yet.
5654     // We keep group a stub group until the size is just under GROUP_SIZE.
5655     // The last input section in the group will be used as the stub table.
5656     FINDING_STUB_SECTION,
5657     // A group is being built and we have already found a stub table.
5658     // We enter this state to grow a stub group by adding input section
5659     // after the stub table.  This effectively doubles the group size.
5660     HAS_STUB_SECTION
5661   } State;
5662
5663   // Any newly created relaxed sections are stored here.
5664   std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5665
5666   State state = NO_GROUP;
5667   section_size_type off = 0;
5668   section_size_type group_begin_offset = 0;
5669   section_size_type group_end_offset = 0;
5670   section_size_type stub_table_end_offset = 0;
5671   Input_section_list::const_iterator group_begin =
5672     this->input_sections().end();
5673   Input_section_list::const_iterator stub_table =
5674     this->input_sections().end();
5675   Input_section_list::const_iterator group_end = this->input_sections().end();
5676   for (Input_section_list::const_iterator p = this->input_sections().begin();
5677        p != this->input_sections().end();
5678        ++p)
5679     {
5680       section_size_type section_begin_offset =
5681         align_address(off, p->addralign());
5682       section_size_type section_end_offset =
5683         section_begin_offset + p->data_size();
5684
5685       // Check to see if we should group the previously seen sections.
5686       switch (state)
5687         {
5688         case NO_GROUP:
5689           break;
5690
5691         case FINDING_STUB_SECTION:
5692           // Adding this section makes the group larger than GROUP_SIZE.
5693           if (section_end_offset - group_begin_offset >= group_size)
5694             {
5695               if (stubs_always_after_branch)
5696                 {
5697                   gold_assert(group_end != this->input_sections().end());
5698                   this->create_stub_group(group_begin, group_end, group_end,
5699                                           target, &new_relaxed_sections,
5700                                           task);
5701                   state = NO_GROUP;
5702                 }
5703               else
5704                 {
5705                   // But wait, there's more!  Input sections up to
5706                   // stub_group_size bytes after the stub table can be
5707                   // handled by it too.
5708                   state = HAS_STUB_SECTION;
5709                   stub_table = group_end;
5710                   stub_table_end_offset = group_end_offset;
5711                 }
5712             }
5713             break;
5714
5715         case HAS_STUB_SECTION:
5716           // Adding this section makes the post stub-section group larger
5717           // than GROUP_SIZE.
5718           if (section_end_offset - stub_table_end_offset >= group_size)
5719            {
5720              gold_assert(group_end != this->input_sections().end());
5721              this->create_stub_group(group_begin, group_end, stub_table,
5722                                      target, &new_relaxed_sections, task);
5723              state = NO_GROUP;
5724            }
5725            break;
5726
5727           default:
5728             gold_unreachable();
5729         }
5730
5731       // If we see an input section and currently there is no group, start
5732       // a new one.  Skip any empty sections.  We look at the data size
5733       // instead of calling p->relobj()->section_size() to avoid locking.
5734       if ((p->is_input_section() || p->is_relaxed_input_section())
5735           && (p->data_size() != 0))
5736         {
5737           if (state == NO_GROUP)
5738             {
5739               state = FINDING_STUB_SECTION;
5740               group_begin = p;
5741               group_begin_offset = section_begin_offset;
5742             }
5743
5744           // Keep track of the last input section seen.
5745           group_end = p;
5746           group_end_offset = section_end_offset;
5747         }
5748
5749       off = section_end_offset;
5750     }
5751
5752   // Create a stub group for any ungrouped sections.
5753   if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5754     {
5755       gold_assert(group_end != this->input_sections().end());
5756       this->create_stub_group(group_begin, group_end,
5757                               (state == FINDING_STUB_SECTION
5758                                ? group_end
5759                                : stub_table),
5760                                target, &new_relaxed_sections, task);
5761     }
5762
5763   // Convert input section into relaxed input section in a batch.
5764   if (!new_relaxed_sections.empty())
5765     this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5766
5767   // Update the section offsets
5768   for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5769     {
5770       Arm_relobj<big_endian>* arm_relobj =
5771         Arm_relobj<big_endian>::as_arm_relobj(
5772           new_relaxed_sections[i]->relobj());
5773       unsigned int shndx = new_relaxed_sections[i]->shndx();
5774       // Tell Arm_relobj that this input section is converted.
5775       arm_relobj->convert_input_section_to_relaxed_section(shndx);
5776     }
5777 }
5778
5779 // Append non empty text sections in this to LIST in ascending
5780 // order of their position in this.
5781
5782 template<bool big_endian>
5783 void
5784 Arm_output_section<big_endian>::append_text_sections_to_list(
5785     Text_section_list* list)
5786 {
5787   gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5788
5789   for (Input_section_list::const_iterator p = this->input_sections().begin();
5790        p != this->input_sections().end();
5791        ++p)
5792     {
5793       // We only care about plain or relaxed input sections.  We also
5794       // ignore any merged sections.
5795       if (p->is_input_section() || p->is_relaxed_input_section())
5796         list->push_back(Text_section_list::value_type(p->relobj(),
5797                                                       p->shndx()));
5798     }
5799 }
5800
5801 template<bool big_endian>
5802 void
5803 Arm_output_section<big_endian>::fix_exidx_coverage(
5804     Layout* layout,
5805     const Text_section_list& sorted_text_sections,
5806     Symbol_table* symtab,
5807     bool merge_exidx_entries,
5808     const Task* task)
5809 {
5810   // We should only do this for the EXIDX output section.
5811   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5812
5813   // We don't want the relaxation loop to undo these changes, so we discard
5814   // the current saved states and take another one after the fix-up.
5815   this->discard_states();
5816
5817   // Remove all input sections.
5818   uint64_t address = this->address();
5819   typedef std::list<Output_section::Input_section> Input_section_list;
5820   Input_section_list input_sections;
5821   this->reset_address_and_file_offset();
5822   this->get_input_sections(address, std::string(""), &input_sections);
5823
5824   if (!this->input_sections().empty())
5825     gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5826
5827   // Go through all the known input sections and record them.
5828   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5829   typedef Unordered_map<Section_id, const Output_section::Input_section*,
5830                         Section_id_hash> Text_to_exidx_map;
5831   Text_to_exidx_map text_to_exidx_map;
5832   for (Input_section_list::const_iterator p = input_sections.begin();
5833        p != input_sections.end();
5834        ++p)
5835     {
5836       // This should never happen.  At this point, we should only see
5837       // plain EXIDX input sections.
5838       gold_assert(!p->is_relaxed_input_section());
5839       text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5840     }
5841
5842   Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5843
5844   // Go over the sorted text sections.
5845   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5846   Section_id_set processed_input_sections;
5847   for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5848        p != sorted_text_sections.end();
5849        ++p)
5850     {
5851       Relobj* relobj = p->first;
5852       unsigned int shndx = p->second;
5853
5854       Arm_relobj<big_endian>* arm_relobj =
5855          Arm_relobj<big_endian>::as_arm_relobj(relobj);
5856       const Arm_exidx_input_section* exidx_input_section =
5857          arm_relobj->exidx_input_section_by_link(shndx);
5858
5859       // If this text section has no EXIDX section or if the EXIDX section
5860       // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5861       // of the last seen EXIDX section.
5862       if (exidx_input_section == NULL || exidx_input_section->has_errors())
5863         {
5864           exidx_fixup.add_exidx_cantunwind_as_needed();
5865           continue;
5866         }
5867
5868       Relobj* exidx_relobj = exidx_input_section->relobj();
5869       unsigned int exidx_shndx = exidx_input_section->shndx();
5870       Section_id sid(exidx_relobj, exidx_shndx);
5871       Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5872       if (iter == text_to_exidx_map.end())
5873         {
5874           // This is odd.  We have not seen this EXIDX input section before.
5875           // We cannot do fix-up.  If we saw a SECTIONS clause in a script,
5876           // issue a warning instead.  We assume the user knows what he
5877           // or she is doing.  Otherwise, this is an error.
5878           if (layout->script_options()->saw_sections_clause())
5879             gold_warning(_("unwinding may not work because EXIDX input section"
5880                            " %u of %s is not in EXIDX output section"),
5881                          exidx_shndx, exidx_relobj->name().c_str());
5882           else
5883             gold_error(_("unwinding may not work because EXIDX input section"
5884                          " %u of %s is not in EXIDX output section"),
5885                        exidx_shndx, exidx_relobj->name().c_str());
5886
5887           exidx_fixup.add_exidx_cantunwind_as_needed();
5888           continue;
5889         }
5890
5891       // We need to access the contents of the EXIDX section, lock the
5892       // object here.
5893       Task_lock_obj<Object> tl(task, exidx_relobj);
5894       section_size_type exidx_size;
5895       const unsigned char* exidx_contents =
5896         exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5897
5898       // Fix up coverage and append input section to output data list.
5899       Arm_exidx_section_offset_map* section_offset_map = NULL;
5900       uint32_t deleted_bytes =
5901         exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5902                                                       exidx_contents,
5903                                                       exidx_size,
5904                                                       &section_offset_map);
5905
5906       if (deleted_bytes == exidx_input_section->size())
5907         {
5908           // The whole EXIDX section got merged.  Remove it from output.
5909           gold_assert(section_offset_map == NULL);
5910           exidx_relobj->set_output_section(exidx_shndx, NULL);
5911
5912           // All local symbols defined in this input section will be dropped.
5913           // We need to adjust output local symbol count.
5914           arm_relobj->set_output_local_symbol_count_needs_update();
5915         }
5916       else if (deleted_bytes > 0)
5917         {
5918           // Some entries are merged.  We need to convert this EXIDX input
5919           // section into a relaxed section.
5920           gold_assert(section_offset_map != NULL);
5921
5922           Arm_exidx_merged_section* merged_section =
5923             new Arm_exidx_merged_section(*exidx_input_section,
5924                                          *section_offset_map, deleted_bytes);
5925           merged_section->build_contents(exidx_contents, exidx_size);
5926
5927           const std::string secname = exidx_relobj->section_name(exidx_shndx);
5928           this->add_relaxed_input_section(layout, merged_section, secname);
5929           arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5930
5931           // All local symbols defined in discarded portions of this input
5932           // section will be dropped.  We need to adjust output local symbol
5933           // count.
5934           arm_relobj->set_output_local_symbol_count_needs_update();
5935         }
5936       else
5937         {
5938           // Just add back the EXIDX input section.
5939           gold_assert(section_offset_map == NULL);
5940           const Output_section::Input_section* pis = iter->second;
5941           gold_assert(pis->is_input_section());
5942           this->add_script_input_section(*pis);
5943         }
5944
5945       processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5946     }
5947
5948   // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5949   exidx_fixup.add_exidx_cantunwind_as_needed();
5950
5951   // Remove any known EXIDX input sections that are not processed.
5952   for (Input_section_list::const_iterator p = input_sections.begin();
5953        p != input_sections.end();
5954        ++p)
5955     {
5956       if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5957           == processed_input_sections.end())
5958         {
5959           // We discard a known EXIDX section because its linked
5960           // text section has been folded by ICF.  We also discard an
5961           // EXIDX section with error, the output does not matter in this
5962           // case.  We do this to avoid triggering asserts.
5963           Arm_relobj<big_endian>* arm_relobj =
5964             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5965           const Arm_exidx_input_section* exidx_input_section =
5966             arm_relobj->exidx_input_section_by_shndx(p->shndx());
5967           gold_assert(exidx_input_section != NULL);
5968           if (!exidx_input_section->has_errors())
5969             {
5970               unsigned int text_shndx = exidx_input_section->link();
5971               gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5972             }
5973
5974           // Remove this from link.  We also need to recount the
5975           // local symbols.
5976           p->relobj()->set_output_section(p->shndx(), NULL);
5977           arm_relobj->set_output_local_symbol_count_needs_update();
5978         }
5979     }
5980
5981   // Link exidx output section to the first seen output section and
5982   // set correct entry size.
5983   this->set_link_section(exidx_fixup.first_output_text_section());
5984   this->set_entsize(8);
5985
5986   // Make changes permanent.
5987   this->save_states();
5988   this->set_section_offsets_need_adjustment();
5989 }
5990
5991 // Link EXIDX output sections to text output sections.
5992
5993 template<bool big_endian>
5994 void
5995 Arm_output_section<big_endian>::set_exidx_section_link()
5996 {
5997   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5998   if (!this->input_sections().empty())
5999     {
6000       Input_section_list::const_iterator p = this->input_sections().begin();
6001       Arm_relobj<big_endian>* arm_relobj =
6002         Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6003       unsigned exidx_shndx = p->shndx();
6004       const Arm_exidx_input_section* exidx_input_section =
6005         arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6006       gold_assert(exidx_input_section != NULL);
6007       unsigned int text_shndx = exidx_input_section->link();
6008       Output_section* os = arm_relobj->output_section(text_shndx);
6009       this->set_link_section(os);
6010     }
6011 }
6012
6013 // Arm_relobj methods.
6014
6015 // Determine if an input section is scannable for stub processing.  SHDR is
6016 // the header of the section and SHNDX is the section index.  OS is the output
6017 // section for the input section and SYMTAB is the global symbol table used to
6018 // look up ICF information.
6019
6020 template<bool big_endian>
6021 bool
6022 Arm_relobj<big_endian>::section_is_scannable(
6023     const elfcpp::Shdr<32, big_endian>& shdr,
6024     unsigned int shndx,
6025     const Output_section* os,
6026     const Symbol_table* symtab)
6027 {
6028   // Skip any empty sections, unallocated sections or sections whose
6029   // type are not SHT_PROGBITS.
6030   if (shdr.get_sh_size() == 0
6031       || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6032       || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6033     return false;
6034
6035   // Skip any discarded or ICF'ed sections.
6036   if (os == NULL || symtab->is_section_folded(this, shndx))
6037     return false;
6038
6039   // If this requires special offset handling, check to see if it is
6040   // a relaxed section.  If this is not, then it is a merged section that
6041   // we cannot handle.
6042   if (this->is_output_section_offset_invalid(shndx))
6043     {
6044       const Output_relaxed_input_section* poris =
6045         os->find_relaxed_input_section(this, shndx);
6046       if (poris == NULL)
6047         return false;
6048     }
6049
6050   return true;
6051 }
6052
6053 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6054 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6055
6056 template<bool big_endian>
6057 bool
6058 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6059     const elfcpp::Shdr<32, big_endian>& shdr,
6060     const Relobj::Output_sections& out_sections,
6061     const Symbol_table* symtab,
6062     const unsigned char* pshdrs)
6063 {
6064   unsigned int sh_type = shdr.get_sh_type();
6065   if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6066     return false;
6067
6068   // Ignore empty section.
6069   off_t sh_size = shdr.get_sh_size();
6070   if (sh_size == 0)
6071     return false;
6072
6073   // Ignore reloc section with unexpected symbol table.  The
6074   // error will be reported in the final link.
6075   if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6076     return false;
6077
6078   unsigned int reloc_size;
6079   if (sh_type == elfcpp::SHT_REL)
6080     reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6081   else
6082     reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6083
6084   // Ignore reloc section with unexpected entsize or uneven size.
6085   // The error will be reported in the final link.
6086   if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6087     return false;
6088
6089   // Ignore reloc section with bad info.  This error will be
6090   // reported in the final link.
6091   unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6092   if (index >= this->shnum())
6093     return false;
6094
6095   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6096   const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6097   return this->section_is_scannable(text_shdr, index,
6098                                    out_sections[index], symtab);
6099 }
6100
6101 // Return the output address of either a plain input section or a relaxed
6102 // input section.  SHNDX is the section index.  We define and use this
6103 // instead of calling Output_section::output_address because that is slow
6104 // for large output.
6105
6106 template<bool big_endian>
6107 Arm_address
6108 Arm_relobj<big_endian>::simple_input_section_output_address(
6109     unsigned int shndx,
6110     Output_section* os)
6111 {
6112   if (this->is_output_section_offset_invalid(shndx))
6113     {
6114       const Output_relaxed_input_section* poris =
6115         os->find_relaxed_input_section(this, shndx);
6116       // We do not handle merged sections here.
6117       gold_assert(poris != NULL);
6118       return poris->address();
6119     }
6120   else
6121     return os->address() + this->get_output_section_offset(shndx);
6122 }
6123
6124 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6125 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6126
6127 template<bool big_endian>
6128 bool
6129 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6130     const elfcpp::Shdr<32, big_endian>& shdr,
6131     unsigned int shndx,
6132     Output_section* os,
6133     const Symbol_table* symtab)
6134 {
6135   if (!this->section_is_scannable(shdr, shndx, os, symtab))
6136     return false;
6137
6138   // If the section does not cross any 4K-boundaries, it does not need to
6139   // be scanned.
6140   Arm_address address = this->simple_input_section_output_address(shndx, os);
6141   if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6142     return false;
6143
6144   return true;
6145 }
6146
6147 // Scan a section for Cortex-A8 workaround.
6148
6149 template<bool big_endian>
6150 void
6151 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6152     const elfcpp::Shdr<32, big_endian>& shdr,
6153     unsigned int shndx,
6154     Output_section* os,
6155     Target_arm<big_endian>* arm_target)
6156 {
6157   // Look for the first mapping symbol in this section.  It should be
6158   // at (shndx, 0).
6159   Mapping_symbol_position section_start(shndx, 0);
6160   typename Mapping_symbols_info::const_iterator p =
6161     this->mapping_symbols_info_.lower_bound(section_start);
6162
6163   // There are no mapping symbols for this section.  Treat it as a data-only
6164   // section.  Issue a warning if section is marked as containing
6165   // instructions.
6166   if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6167     {
6168       if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6169         gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6170                        "erratum because it has no mapping symbols."),
6171                      shndx, this->name().c_str());
6172       return;
6173     }
6174
6175   Arm_address output_address =
6176     this->simple_input_section_output_address(shndx, os);
6177
6178   // Get the section contents.
6179   section_size_type input_view_size = 0;
6180   const unsigned char* input_view =
6181     this->section_contents(shndx, &input_view_size, false);
6182
6183   // We need to go through the mapping symbols to determine what to
6184   // scan.  There are two reasons.  First, we should look at THUMB code and
6185   // THUMB code only.  Second, we only want to look at the 4K-page boundary
6186   // to speed up the scanning.
6187
6188   while (p != this->mapping_symbols_info_.end()
6189         && p->first.first == shndx)
6190     {
6191       typename Mapping_symbols_info::const_iterator next =
6192         this->mapping_symbols_info_.upper_bound(p->first);
6193
6194       // Only scan part of a section with THUMB code.
6195       if (p->second == 't')
6196         {
6197           // Determine the end of this range.
6198           section_size_type span_start =
6199             convert_to_section_size_type(p->first.second);
6200           section_size_type span_end;
6201           if (next != this->mapping_symbols_info_.end()
6202               && next->first.first == shndx)
6203             span_end = convert_to_section_size_type(next->first.second);
6204           else
6205             span_end = convert_to_section_size_type(shdr.get_sh_size());
6206
6207           if (((span_start + output_address) & ~0xfffUL)
6208               != ((span_end + output_address - 1) & ~0xfffUL))
6209             {
6210               arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6211                                                           span_start, span_end,
6212                                                           input_view,
6213                                                           output_address);
6214             }
6215         }
6216
6217       p = next;
6218     }
6219 }
6220
6221 // Scan relocations for stub generation.
6222
6223 template<bool big_endian>
6224 void
6225 Arm_relobj<big_endian>::scan_sections_for_stubs(
6226     Target_arm<big_endian>* arm_target,
6227     const Symbol_table* symtab,
6228     const Layout* layout)
6229 {
6230   unsigned int shnum = this->shnum();
6231   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6232
6233   // Read the section headers.
6234   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6235                                                shnum * shdr_size,
6236                                                true, true);
6237
6238   // To speed up processing, we set up hash tables for fast lookup of
6239   // input offsets to output addresses.
6240   this->initialize_input_to_output_maps();
6241
6242   const Relobj::Output_sections& out_sections(this->output_sections());
6243
6244   Relocate_info<32, big_endian> relinfo;
6245   relinfo.symtab = symtab;
6246   relinfo.layout = layout;
6247   relinfo.object = this;
6248
6249   // Do relocation stubs scanning.
6250   const unsigned char* p = pshdrs + shdr_size;
6251   for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6252     {
6253       const elfcpp::Shdr<32, big_endian> shdr(p);
6254       if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6255                                                   pshdrs))
6256         {
6257           unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6258           Arm_address output_offset = this->get_output_section_offset(index);
6259           Arm_address output_address;
6260           if (output_offset != invalid_address)
6261             output_address = out_sections[index]->address() + output_offset;
6262           else
6263             {
6264               // Currently this only happens for a relaxed section.
6265               const Output_relaxed_input_section* poris =
6266               out_sections[index]->find_relaxed_input_section(this, index);
6267               gold_assert(poris != NULL);
6268               output_address = poris->address();
6269             }
6270
6271           // Get the relocations.
6272           const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6273                                                         shdr.get_sh_size(),
6274                                                         true, false);
6275
6276           // Get the section contents.  This does work for the case in which
6277           // we modify the contents of an input section.  We need to pass the
6278           // output view under such circumstances.
6279           section_size_type input_view_size = 0;
6280           const unsigned char* input_view =
6281             this->section_contents(index, &input_view_size, false);
6282
6283           relinfo.reloc_shndx = i;
6284           relinfo.data_shndx = index;
6285           unsigned int sh_type = shdr.get_sh_type();
6286           unsigned int reloc_size;
6287           if (sh_type == elfcpp::SHT_REL)
6288             reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6289           else
6290             reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6291
6292           Output_section* os = out_sections[index];
6293           arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6294                                              shdr.get_sh_size() / reloc_size,
6295                                              os,
6296                                              output_offset == invalid_address,
6297                                              input_view, output_address,
6298                                              input_view_size);
6299         }
6300     }
6301
6302   // Do Cortex-A8 erratum stubs scanning.  This has to be done for a section
6303   // after its relocation section, if there is one, is processed for
6304   // relocation stubs.  Merging this loop with the one above would have been
6305   // complicated since we would have had to make sure that relocation stub
6306   // scanning is done first.
6307   if (arm_target->fix_cortex_a8())
6308     {
6309       const unsigned char* p = pshdrs + shdr_size;
6310       for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6311         {
6312           const elfcpp::Shdr<32, big_endian> shdr(p);
6313           if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6314                                                           out_sections[i],
6315                                                           symtab))
6316             this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6317                                                      arm_target);
6318         }
6319     }
6320
6321   // After we've done the relocations, we release the hash tables,
6322   // since we no longer need them.
6323   this->free_input_to_output_maps();
6324 }
6325
6326 // Count the local symbols.  The ARM backend needs to know if a symbol
6327 // is a THUMB function or not.  For global symbols, it is easy because
6328 // the Symbol object keeps the ELF symbol type.  For local symbol it is
6329 // harder because we cannot access this information.   So we override the
6330 // do_count_local_symbol in parent and scan local symbols to mark
6331 // THUMB functions.  This is not the most efficient way but I do not want to
6332 // slow down other ports by calling a per symbol target hook inside
6333 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6334
6335 template<bool big_endian>
6336 void
6337 Arm_relobj<big_endian>::do_count_local_symbols(
6338     Stringpool_template<char>* pool,
6339     Stringpool_template<char>* dynpool)
6340 {
6341   // We need to fix-up the values of any local symbols whose type are
6342   // STT_ARM_TFUNC.
6343
6344   // Ask parent to count the local symbols.
6345   Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6346   const unsigned int loccount = this->local_symbol_count();
6347   if (loccount == 0)
6348     return;
6349
6350   // Initialize the thumb function bit-vector.
6351   std::vector<bool> empty_vector(loccount, false);
6352   this->local_symbol_is_thumb_function_.swap(empty_vector);
6353
6354   // Read the symbol table section header.
6355   const unsigned int symtab_shndx = this->symtab_shndx();
6356   elfcpp::Shdr<32, big_endian>
6357       symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6358   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6359
6360   // Read the local symbols.
6361   const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6362   gold_assert(loccount == symtabshdr.get_sh_info());
6363   off_t locsize = loccount * sym_size;
6364   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6365                                               locsize, true, true);
6366
6367   // For mapping symbol processing, we need to read the symbol names.
6368   unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6369   if (strtab_shndx >= this->shnum())
6370     {
6371       this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6372       return;
6373     }
6374
6375   elfcpp::Shdr<32, big_endian>
6376     strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6377   if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6378     {
6379       this->error(_("symbol table name section has wrong type: %u"),
6380                   static_cast<unsigned int>(strtabshdr.get_sh_type()));
6381       return;
6382     }
6383   const char* pnames =
6384     reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6385                                                  strtabshdr.get_sh_size(),
6386                                                  false, false));
6387
6388   // Loop over the local symbols and mark any local symbols pointing
6389   // to THUMB functions.
6390
6391   // Skip the first dummy symbol.
6392   psyms += sym_size;
6393   typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6394     this->local_values();
6395   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6396     {
6397       elfcpp::Sym<32, big_endian> sym(psyms);
6398       elfcpp::STT st_type = sym.get_st_type();
6399       Symbol_value<32>& lv((*plocal_values)[i]);
6400       Arm_address input_value = lv.input_value();
6401
6402       // Check to see if this is a mapping symbol.
6403       const char* sym_name = pnames + sym.get_st_name();
6404       if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6405         {
6406           bool is_ordinary;
6407           unsigned int input_shndx =
6408             this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6409           gold_assert(is_ordinary);
6410
6411           // Strip of LSB in case this is a THUMB symbol.
6412           Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6413           this->mapping_symbols_info_[msp] = sym_name[1];
6414         }
6415
6416       if (st_type == elfcpp::STT_ARM_TFUNC
6417           || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6418         {
6419           // This is a THUMB function.  Mark this and canonicalize the
6420           // symbol value by setting LSB.
6421           this->local_symbol_is_thumb_function_[i] = true;
6422           if ((input_value & 1) == 0)
6423             lv.set_input_value(input_value | 1);
6424         }
6425     }
6426 }
6427
6428 // Relocate sections.
6429 template<bool big_endian>
6430 void
6431 Arm_relobj<big_endian>::do_relocate_sections(
6432     const Symbol_table* symtab,
6433     const Layout* layout,
6434     const unsigned char* pshdrs,
6435     Output_file* of,
6436     typename Sized_relobj_file<32, big_endian>::Views* pviews)
6437 {
6438   // Call parent to relocate sections.
6439   Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6440                                                           pshdrs, of, pviews);
6441
6442   // We do not generate stubs if doing a relocatable link.
6443   if (parameters->options().relocatable())
6444     return;
6445
6446   // Relocate stub tables.
6447   unsigned int shnum = this->shnum();
6448
6449   Target_arm<big_endian>* arm_target =
6450     Target_arm<big_endian>::default_target();
6451
6452   Relocate_info<32, big_endian> relinfo;
6453   relinfo.symtab = symtab;
6454   relinfo.layout = layout;
6455   relinfo.object = this;
6456
6457   for (unsigned int i = 1; i < shnum; ++i)
6458     {
6459       Arm_input_section<big_endian>* arm_input_section =
6460         arm_target->find_arm_input_section(this, i);
6461
6462       if (arm_input_section != NULL
6463           && arm_input_section->is_stub_table_owner()
6464           && !arm_input_section->stub_table()->empty())
6465         {
6466           // We cannot discard a section if it owns a stub table.
6467           Output_section* os = this->output_section(i);
6468           gold_assert(os != NULL);
6469
6470           relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6471           relinfo.reloc_shdr = NULL;
6472           relinfo.data_shndx = i;
6473           relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6474
6475           gold_assert((*pviews)[i].view != NULL);
6476
6477           // We are passed the output section view.  Adjust it to cover the
6478           // stub table only.
6479           Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6480           gold_assert((stub_table->address() >= (*pviews)[i].address)
6481                       && ((stub_table->address() + stub_table->data_size())
6482                           <= (*pviews)[i].address + (*pviews)[i].view_size));
6483
6484           off_t offset = stub_table->address() - (*pviews)[i].address;
6485           unsigned char* view = (*pviews)[i].view + offset;
6486           Arm_address address = stub_table->address();
6487           section_size_type view_size = stub_table->data_size();
6488
6489           stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6490                                      view_size);
6491         }
6492
6493       // Apply Cortex A8 workaround if applicable.
6494       if (this->section_has_cortex_a8_workaround(i))
6495         {
6496           unsigned char* view = (*pviews)[i].view;
6497           Arm_address view_address = (*pviews)[i].address;
6498           section_size_type view_size = (*pviews)[i].view_size;
6499           Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6500
6501           // Adjust view to cover section.
6502           Output_section* os = this->output_section(i);
6503           gold_assert(os != NULL);
6504           Arm_address section_address =
6505             this->simple_input_section_output_address(i, os);
6506           uint64_t section_size = this->section_size(i);
6507
6508           gold_assert(section_address >= view_address
6509                       && ((section_address + section_size)
6510                           <= (view_address + view_size)));
6511
6512           unsigned char* section_view = view + (section_address - view_address);
6513
6514           // Apply the Cortex-A8 workaround to the output address range
6515           // corresponding to this input section.
6516           stub_table->apply_cortex_a8_workaround_to_address_range(
6517               arm_target,
6518               section_view,
6519               section_address,
6520               section_size);
6521         }
6522     }
6523 }
6524
6525 // Find the linked text section of an EXIDX section by looking at the first
6526 // relocation.  4.4.1 of the EHABI specifications says that an EXIDX section
6527 // must be linked to its associated code section via the sh_link field of
6528 // its section header.  However, some tools are broken and the link is not
6529 // always set.  LD just drops such an EXIDX section silently, causing the
6530 // associated code not unwindabled.   Here we try a little bit harder to
6531 // discover the linked code section.
6532 //
6533 // PSHDR points to the section header of a relocation section of an EXIDX
6534 // section.  If we can find a linked text section, return true and
6535 // store the text section index in the location PSHNDX.  Otherwise
6536 // return false.
6537
6538 template<bool big_endian>
6539 bool
6540 Arm_relobj<big_endian>::find_linked_text_section(
6541     const unsigned char* pshdr,
6542     const unsigned char* psyms,
6543     unsigned int* pshndx)
6544 {
6545   elfcpp::Shdr<32, big_endian> shdr(pshdr);
6546
6547   // If there is no relocation, we cannot find the linked text section.
6548   size_t reloc_size;
6549   if (shdr.get_sh_type() == elfcpp::SHT_REL)
6550       reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6551   else
6552       reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6553   size_t reloc_count = shdr.get_sh_size() / reloc_size;
6554
6555   // Get the relocations.
6556   const unsigned char* prelocs =
6557       this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6558
6559   // Find the REL31 relocation for the first word of the first EXIDX entry.
6560   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6561     {
6562       Arm_address r_offset;
6563       typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6564       if (shdr.get_sh_type() == elfcpp::SHT_REL)
6565         {
6566           typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6567           r_info = reloc.get_r_info();
6568           r_offset = reloc.get_r_offset();
6569         }
6570       else
6571         {
6572           typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6573           r_info = reloc.get_r_info();
6574           r_offset = reloc.get_r_offset();
6575         }
6576
6577       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6578       if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6579         continue;
6580
6581       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6582       if (r_sym == 0
6583           || r_sym >= this->local_symbol_count()
6584           || r_offset != 0)
6585         continue;
6586
6587       // This is the relocation for the first word of the first EXIDX entry.
6588       // We expect to see a local section symbol.
6589       const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6590       elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6591       if (sym.get_st_type() == elfcpp::STT_SECTION)
6592         {
6593           bool is_ordinary;
6594           *pshndx =
6595             this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6596           gold_assert(is_ordinary);
6597           return true;
6598         }
6599       else
6600         return false;
6601     }
6602
6603   return false;
6604 }
6605
6606 // Make an EXIDX input section object for an EXIDX section whose index is
6607 // SHNDX.  SHDR is the section header of the EXIDX section and TEXT_SHNDX
6608 // is the section index of the linked text section.
6609
6610 template<bool big_endian>
6611 void
6612 Arm_relobj<big_endian>::make_exidx_input_section(
6613     unsigned int shndx,
6614     const elfcpp::Shdr<32, big_endian>& shdr,
6615     unsigned int text_shndx,
6616     const elfcpp::Shdr<32, big_endian>& text_shdr)
6617 {
6618   // Create an Arm_exidx_input_section object for this EXIDX section.
6619   Arm_exidx_input_section* exidx_input_section =
6620     new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6621                                 shdr.get_sh_addralign(),
6622                                 text_shdr.get_sh_size());
6623
6624   gold_assert(this->exidx_section_map_[shndx] == NULL);
6625   this->exidx_section_map_[shndx] = exidx_input_section;
6626
6627   if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6628     {
6629       gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6630                  this->section_name(shndx).c_str(), shndx, text_shndx,
6631                  this->name().c_str());
6632       exidx_input_section->set_has_errors();
6633     }
6634   else if (this->exidx_section_map_[text_shndx] != NULL)
6635     {
6636       unsigned other_exidx_shndx =
6637         this->exidx_section_map_[text_shndx]->shndx();
6638       gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6639                    "%s(%u) in %s"),
6640                  this->section_name(shndx).c_str(), shndx,
6641                  this->section_name(other_exidx_shndx).c_str(),
6642                  other_exidx_shndx, this->section_name(text_shndx).c_str(),
6643                  text_shndx, this->name().c_str());
6644       exidx_input_section->set_has_errors();
6645     }
6646   else
6647      this->exidx_section_map_[text_shndx] = exidx_input_section;
6648
6649   // Check section flags of text section.
6650   if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6651     {
6652       gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6653                    " in %s"),
6654                  this->section_name(shndx).c_str(), shndx,
6655                  this->section_name(text_shndx).c_str(), text_shndx,
6656                  this->name().c_str());
6657       exidx_input_section->set_has_errors();
6658     }
6659   else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6660     // I would like to make this an error but currently ld just ignores
6661     // this.
6662     gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6663                    "%s(%u) in %s"),
6664                  this->section_name(shndx).c_str(), shndx,
6665                  this->section_name(text_shndx).c_str(), text_shndx,
6666                  this->name().c_str());
6667 }
6668
6669 // Read the symbol information.
6670
6671 template<bool big_endian>
6672 void
6673 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6674 {
6675   // Call parent class to read symbol information.
6676   Sized_relobj_file<32, big_endian>::do_read_symbols(sd);
6677
6678   // If this input file is a binary file, it has no processor
6679   // specific flags and attributes section.
6680   Input_file::Format format = this->input_file()->format();
6681   if (format != Input_file::FORMAT_ELF)
6682     {
6683       gold_assert(format == Input_file::FORMAT_BINARY);
6684       this->merge_flags_and_attributes_ = false;
6685       return;
6686     }
6687
6688   // Read processor-specific flags in ELF file header.
6689   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6690                                               elfcpp::Elf_sizes<32>::ehdr_size,
6691                                               true, false);
6692   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6693   this->processor_specific_flags_ = ehdr.get_e_flags();
6694
6695   // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6696   // sections.
6697   std::vector<unsigned int> deferred_exidx_sections;
6698   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6699   const unsigned char* pshdrs = sd->section_headers->data();
6700   const unsigned char* ps = pshdrs + shdr_size;
6701   bool must_merge_flags_and_attributes = false;
6702   for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6703     {
6704       elfcpp::Shdr<32, big_endian> shdr(ps);
6705
6706       // Sometimes an object has no contents except the section name string
6707       // table and an empty symbol table with the undefined symbol.  We
6708       // don't want to merge processor-specific flags from such an object.
6709       if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6710         {
6711           // Symbol table is not empty.
6712           const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6713              elfcpp::Elf_sizes<32>::sym_size;
6714           if (shdr.get_sh_size() > sym_size)
6715             must_merge_flags_and_attributes = true;
6716         }
6717       else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6718         // If this is neither an empty symbol table nor a string table,
6719         // be conservative.
6720         must_merge_flags_and_attributes = true;
6721
6722       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6723         {
6724           gold_assert(this->attributes_section_data_ == NULL);
6725           section_offset_type section_offset = shdr.get_sh_offset();
6726           section_size_type section_size =
6727             convert_to_section_size_type(shdr.get_sh_size());
6728           const unsigned char* view =
6729              this->get_view(section_offset, section_size, true, false);
6730           this->attributes_section_data_ =
6731             new Attributes_section_data(view, section_size);
6732         }
6733       else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6734         {
6735           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6736           if (text_shndx == elfcpp::SHN_UNDEF)
6737             deferred_exidx_sections.push_back(i);
6738           else
6739             {
6740               elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6741                                                      + text_shndx * shdr_size);
6742               this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6743             }
6744           // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6745           if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6746             gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6747                          this->section_name(i).c_str(), this->name().c_str());
6748         }
6749     }
6750
6751   // This is rare.
6752   if (!must_merge_flags_and_attributes)
6753     {
6754       gold_assert(deferred_exidx_sections.empty());
6755       this->merge_flags_and_attributes_ = false;
6756       return;
6757     }
6758
6759   // Some tools are broken and they do not set the link of EXIDX sections.
6760   // We look at the first relocation to figure out the linked sections.
6761   if (!deferred_exidx_sections.empty())
6762     {
6763       // We need to go over the section headers again to find the mapping
6764       // from sections being relocated to their relocation sections.  This is
6765       // a bit inefficient as we could do that in the loop above.  However,
6766       // we do not expect any deferred EXIDX sections normally.  So we do not
6767       // want to slow down the most common path.
6768       typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6769       Reloc_map reloc_map;
6770       ps = pshdrs + shdr_size;
6771       for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6772         {
6773           elfcpp::Shdr<32, big_endian> shdr(ps);
6774           elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6775           if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6776             {
6777               unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6778               if (info_shndx >= this->shnum())
6779                 gold_error(_("relocation section %u has invalid info %u"),
6780                            i, info_shndx);
6781               Reloc_map::value_type value(info_shndx, i);
6782               std::pair<Reloc_map::iterator, bool> result =
6783                 reloc_map.insert(value);
6784               if (!result.second)
6785                 gold_error(_("section %u has multiple relocation sections "
6786                              "%u and %u"),
6787                            info_shndx, i, reloc_map[info_shndx]);
6788             }
6789         }
6790
6791       // Read the symbol table section header.
6792       const unsigned int symtab_shndx = this->symtab_shndx();
6793       elfcpp::Shdr<32, big_endian>
6794           symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6795       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6796
6797       // Read the local symbols.
6798       const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6799       const unsigned int loccount = this->local_symbol_count();
6800       gold_assert(loccount == symtabshdr.get_sh_info());
6801       off_t locsize = loccount * sym_size;
6802       const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6803                                                   locsize, true, true);
6804
6805       // Process the deferred EXIDX sections.
6806       for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6807         {
6808           unsigned int shndx = deferred_exidx_sections[i];
6809           elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6810           unsigned int text_shndx = elfcpp::SHN_UNDEF;
6811           Reloc_map::const_iterator it = reloc_map.find(shndx);
6812           if (it != reloc_map.end())
6813             find_linked_text_section(pshdrs + it->second * shdr_size,
6814                                      psyms, &text_shndx);
6815           elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6816                                                  + text_shndx * shdr_size);
6817           this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6818         }
6819     }
6820 }
6821
6822 // Process relocations for garbage collection.  The ARM target uses .ARM.exidx
6823 // sections for unwinding.  These sections are referenced implicitly by
6824 // text sections linked in the section headers.  If we ignore these implicit
6825 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6826 // will be garbage-collected incorrectly.  Hence we override the same function
6827 // in the base class to handle these implicit references.
6828
6829 template<bool big_endian>
6830 void
6831 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6832                                              Layout* layout,
6833                                              Read_relocs_data* rd)
6834 {
6835   // First, call base class method to process relocations in this object.
6836   Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6837
6838   // If --gc-sections is not specified, there is nothing more to do.
6839   // This happens when --icf is used but --gc-sections is not.
6840   if (!parameters->options().gc_sections())
6841     return;
6842
6843   unsigned int shnum = this->shnum();
6844   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6845   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6846                                                shnum * shdr_size,
6847                                                true, true);
6848
6849   // Scan section headers for sections of type SHT_ARM_EXIDX.  Add references
6850   // to these from the linked text sections.
6851   const unsigned char* ps = pshdrs + shdr_size;
6852   for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6853     {
6854       elfcpp::Shdr<32, big_endian> shdr(ps);
6855       if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6856         {
6857           // Found an .ARM.exidx section, add it to the set of reachable
6858           // sections from its linked text section.
6859           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6860           symtab->gc()->add_reference(this, text_shndx, this, i);
6861         }
6862     }
6863 }
6864
6865 // Update output local symbol count.  Owing to EXIDX entry merging, some local
6866 // symbols  will be removed in output.  Adjust output local symbol count
6867 // accordingly.  We can only changed the static output local symbol count.  It
6868 // is too late to change the dynamic symbols.
6869
6870 template<bool big_endian>
6871 void
6872 Arm_relobj<big_endian>::update_output_local_symbol_count()
6873 {
6874   // Caller should check that this needs updating.  We want caller checking
6875   // because output_local_symbol_count_needs_update() is most likely inlined.
6876   gold_assert(this->output_local_symbol_count_needs_update_);
6877
6878   gold_assert(this->symtab_shndx() != -1U);
6879   if (this->symtab_shndx() == 0)
6880     {
6881       // This object has no symbols.  Weird but legal.
6882       return;
6883     }
6884
6885   // Read the symbol table section header.
6886   const unsigned int symtab_shndx = this->symtab_shndx();
6887   elfcpp::Shdr<32, big_endian>
6888     symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6889   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6890
6891   // Read the local symbols.
6892   const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6893   const unsigned int loccount = this->local_symbol_count();
6894   gold_assert(loccount == symtabshdr.get_sh_info());
6895   off_t locsize = loccount * sym_size;
6896   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6897                                               locsize, true, true);
6898
6899   // Loop over the local symbols.
6900
6901   typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6902      Output_sections;
6903   const Output_sections& out_sections(this->output_sections());
6904   unsigned int shnum = this->shnum();
6905   unsigned int count = 0;
6906   // Skip the first, dummy, symbol.
6907   psyms += sym_size;
6908   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6909     {
6910       elfcpp::Sym<32, big_endian> sym(psyms);
6911
6912       Symbol_value<32>& lv((*this->local_values())[i]);
6913
6914       // This local symbol was already discarded by do_count_local_symbols.
6915       if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6916         continue;
6917
6918       bool is_ordinary;
6919       unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6920                                                   &is_ordinary);
6921
6922       if (shndx < shnum)
6923         {
6924           Output_section* os = out_sections[shndx];
6925
6926           // This local symbol no longer has an output section.  Discard it.
6927           if (os == NULL)
6928             {
6929               lv.set_no_output_symtab_entry();
6930               continue;
6931             }
6932
6933           // Currently we only discard parts of EXIDX input sections.
6934           // We explicitly check for a merged EXIDX input section to avoid
6935           // calling Output_section_data::output_offset unless necessary.
6936           if ((this->get_output_section_offset(shndx) == invalid_address)
6937               && (this->exidx_input_section_by_shndx(shndx) != NULL))
6938             {
6939               section_offset_type output_offset =
6940                 os->output_offset(this, shndx, lv.input_value());
6941               if (output_offset == -1)
6942                 {
6943                   // This symbol is defined in a part of an EXIDX input section
6944                   // that is discarded due to entry merging.
6945                   lv.set_no_output_symtab_entry();
6946                   continue;
6947                 }
6948             }
6949         }
6950
6951       ++count;
6952     }
6953
6954   this->set_output_local_symbol_count(count);
6955   this->output_local_symbol_count_needs_update_ = false;
6956 }
6957
6958 // Arm_dynobj methods.
6959
6960 // Read the symbol information.
6961
6962 template<bool big_endian>
6963 void
6964 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6965 {
6966   // Call parent class to read symbol information.
6967   Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6968
6969   // Read processor-specific flags in ELF file header.
6970   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6971                                               elfcpp::Elf_sizes<32>::ehdr_size,
6972                                               true, false);
6973   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6974   this->processor_specific_flags_ = ehdr.get_e_flags();
6975
6976   // Read the attributes section if there is one.
6977   // We read from the end because gas seems to put it near the end of
6978   // the section headers.
6979   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6980   const unsigned char* ps =
6981     sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6982   for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6983     {
6984       elfcpp::Shdr<32, big_endian> shdr(ps);
6985       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6986         {
6987           section_offset_type section_offset = shdr.get_sh_offset();
6988           section_size_type section_size =
6989             convert_to_section_size_type(shdr.get_sh_size());
6990           const unsigned char* view =
6991             this->get_view(section_offset, section_size, true, false);
6992           this->attributes_section_data_ =
6993             new Attributes_section_data(view, section_size);
6994           break;
6995         }
6996     }
6997 }
6998
6999 // Stub_addend_reader methods.
7000
7001 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7002
7003 template<bool big_endian>
7004 elfcpp::Elf_types<32>::Elf_Swxword
7005 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7006     unsigned int r_type,
7007     const unsigned char* view,
7008     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7009 {
7010   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
7011
7012   switch (r_type)
7013     {
7014     case elfcpp::R_ARM_CALL:
7015     case elfcpp::R_ARM_JUMP24:
7016     case elfcpp::R_ARM_PLT32:
7017       {
7018         typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7019         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7020         Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7021         return Bits<26>::sign_extend32(val << 2);
7022       }
7023
7024     case elfcpp::R_ARM_THM_CALL:
7025     case elfcpp::R_ARM_THM_JUMP24:
7026     case elfcpp::R_ARM_THM_XPC22:
7027       {
7028         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7029         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7030         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7031         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7032         return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7033       }
7034
7035     case elfcpp::R_ARM_THM_JUMP19:
7036       {
7037         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7038         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7039         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7040         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7041         return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7042       }
7043
7044     default:
7045       gold_unreachable();
7046     }
7047 }
7048
7049 // Arm_output_data_got methods.
7050
7051 // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
7052 // The first one is initialized to be 1, which is the module index for
7053 // the main executable and the second one 0.  A reloc of the type
7054 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7055 // be applied by gold.  GSYM is a global symbol.
7056 //
7057 template<bool big_endian>
7058 void
7059 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7060     unsigned int got_type,
7061     Symbol* gsym)
7062 {
7063   if (gsym->has_got_offset(got_type))
7064     return;
7065
7066   // We are doing a static link.  Just mark it as belong to module 1,
7067   // the executable.
7068   unsigned int got_offset = this->add_constant(1);
7069   gsym->set_got_offset(got_type, got_offset);
7070   got_offset = this->add_constant(0);
7071   this->static_relocs_.push_back(Static_reloc(got_offset,
7072                                               elfcpp::R_ARM_TLS_DTPOFF32,
7073                                               gsym));
7074 }
7075
7076 // Same as the above but for a local symbol.
7077
7078 template<bool big_endian>
7079 void
7080 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7081   unsigned int got_type,
7082   Sized_relobj_file<32, big_endian>* object,
7083   unsigned int index)
7084 {
7085   if (object->local_has_got_offset(index, got_type))
7086     return;
7087
7088   // We are doing a static link.  Just mark it as belong to module 1,
7089   // the executable.
7090   unsigned int got_offset = this->add_constant(1);
7091   object->set_local_got_offset(index, got_type, got_offset);
7092   got_offset = this->add_constant(0);
7093   this->static_relocs_.push_back(Static_reloc(got_offset,
7094                                               elfcpp::R_ARM_TLS_DTPOFF32,
7095                                               object, index));
7096 }
7097
7098 template<bool big_endian>
7099 void
7100 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7101 {
7102   // Call parent to write out GOT.
7103   Output_data_got<32, big_endian>::do_write(of);
7104
7105   // We are done if there is no fix up.
7106   if (this->static_relocs_.empty())
7107     return;
7108
7109   gold_assert(parameters->doing_static_link());
7110
7111   const off_t offset = this->offset();
7112   const section_size_type oview_size =
7113     convert_to_section_size_type(this->data_size());
7114   unsigned char* const oview = of->get_output_view(offset, oview_size);
7115
7116   Output_segment* tls_segment = this->layout_->tls_segment();
7117   gold_assert(tls_segment != NULL);
7118
7119   // The thread pointer $tp points to the TCB, which is followed by the
7120   // TLS.  So we need to adjust $tp relative addressing by this amount.
7121   Arm_address aligned_tcb_size =
7122     align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7123
7124   for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7125     {
7126       Static_reloc& reloc(this->static_relocs_[i]);
7127
7128       Arm_address value;
7129       if (!reloc.symbol_is_global())
7130         {
7131           Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7132           const Symbol_value<32>* psymval =
7133             reloc.relobj()->local_symbol(reloc.index());
7134
7135           // We are doing static linking.  Issue an error and skip this
7136           // relocation if the symbol is undefined or in a discarded_section.
7137           bool is_ordinary;
7138           unsigned int shndx = psymval->input_shndx(&is_ordinary);
7139           if ((shndx == elfcpp::SHN_UNDEF)
7140               || (is_ordinary
7141                   && shndx != elfcpp::SHN_UNDEF
7142                   && !object->is_section_included(shndx)
7143                   && !this->symbol_table_->is_section_folded(object, shndx)))
7144             {
7145               gold_error(_("undefined or discarded local symbol %u from "
7146                            " object %s in GOT"),
7147                          reloc.index(), reloc.relobj()->name().c_str());
7148               continue;
7149             }
7150
7151           value = psymval->value(object, 0);
7152         }
7153       else
7154         {
7155           const Symbol* gsym = reloc.symbol();
7156           gold_assert(gsym != NULL);
7157           if (gsym->is_forwarder())
7158             gsym = this->symbol_table_->resolve_forwards(gsym);
7159
7160           // We are doing static linking.  Issue an error and skip this
7161           // relocation if the symbol is undefined or in a discarded_section
7162           // unless it is a weakly_undefined symbol.
7163           if ((gsym->is_defined_in_discarded_section()
7164                || gsym->is_undefined())
7165               && !gsym->is_weak_undefined())
7166             {
7167               gold_error(_("undefined or discarded symbol %s in GOT"),
7168                          gsym->name());
7169               continue;
7170             }
7171
7172           if (!gsym->is_weak_undefined())
7173             {
7174               const Sized_symbol<32>* sym =
7175                 static_cast<const Sized_symbol<32>*>(gsym);
7176               value = sym->value();
7177             }
7178           else
7179               value = 0;
7180         }
7181
7182       unsigned got_offset = reloc.got_offset();
7183       gold_assert(got_offset < oview_size);
7184
7185       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7186       Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7187       Valtype x;
7188       switch (reloc.r_type())
7189         {
7190         case elfcpp::R_ARM_TLS_DTPOFF32:
7191           x = value;
7192           break;
7193         case elfcpp::R_ARM_TLS_TPOFF32:
7194           x = value + aligned_tcb_size;
7195           break;
7196         default:
7197           gold_unreachable();
7198         }
7199       elfcpp::Swap<32, big_endian>::writeval(wv, x);
7200     }
7201
7202   of->write_output_view(offset, oview_size, oview);
7203 }
7204
7205 // A class to handle the PLT data.
7206 // This is an abstract base class that handles most of the linker details
7207 // but does not know the actual contents of PLT entries.  The derived
7208 // classes below fill in those details.
7209
7210 template<bool big_endian>
7211 class Output_data_plt_arm : public Output_section_data
7212 {
7213  public:
7214   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7215     Reloc_section;
7216
7217   Output_data_plt_arm(Layout*, uint64_t addralign, Output_data_space*);
7218
7219   // Add an entry to the PLT.
7220   void
7221   add_entry(Symbol* gsym);
7222
7223   // Return the .rel.plt section data.
7224   const Reloc_section*
7225   rel_plt() const
7226   { return this->rel_; }
7227
7228   // Return the number of PLT entries.
7229   unsigned int
7230   entry_count() const
7231   { return this->count_; }
7232
7233   // Return the offset of the first non-reserved PLT entry.
7234   unsigned int
7235   first_plt_entry_offset() const
7236   { return this->do_first_plt_entry_offset(); }
7237
7238   // Return the size of a PLT entry.
7239   unsigned int
7240   get_plt_entry_size() const
7241   { return this->do_get_plt_entry_size(); }
7242
7243  protected:
7244   // Fill in the first PLT entry.
7245   void
7246   fill_first_plt_entry(unsigned char* pov,
7247                        Arm_address got_address,
7248                        Arm_address plt_address)
7249   { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
7250
7251   void
7252   fill_plt_entry(unsigned char* pov,
7253                  Arm_address got_address,
7254                  Arm_address plt_address,
7255                  unsigned int got_offset,
7256                  unsigned int plt_offset)
7257   { do_fill_plt_entry(pov, got_address, plt_address, got_offset, plt_offset); }
7258
7259   virtual unsigned int
7260   do_first_plt_entry_offset() const = 0;
7261
7262   virtual unsigned int
7263   do_get_plt_entry_size() const = 0;
7264
7265   virtual void
7266   do_fill_first_plt_entry(unsigned char* pov,
7267                           Arm_address got_address,
7268                           Arm_address plt_address) = 0;
7269
7270   virtual void
7271   do_fill_plt_entry(unsigned char* pov,
7272                     Arm_address got_address,
7273                     Arm_address plt_address,
7274                     unsigned int got_offset,
7275                     unsigned int plt_offset) = 0;
7276
7277   void
7278   do_adjust_output_section(Output_section* os);
7279
7280   // Write to a map file.
7281   void
7282   do_print_to_mapfile(Mapfile* mapfile) const
7283   { mapfile->print_output_data(this, _("** PLT")); }
7284
7285  private:
7286   // Set the final size.
7287   void
7288   set_final_data_size()
7289   {
7290     this->set_data_size(this->first_plt_entry_offset()
7291                         + this->count_ * this->get_plt_entry_size());
7292   }
7293
7294   // Write out the PLT data.
7295   void
7296   do_write(Output_file*);
7297
7298   // The reloc section.
7299   Reloc_section* rel_;
7300   // The .got.plt section.
7301   Output_data_space* got_plt_;
7302   // The number of PLT entries.
7303   unsigned int count_;
7304 };
7305
7306 // Create the PLT section.  The ordinary .got section is an argument,
7307 // since we need to refer to the start.  We also create our own .got
7308 // section just for PLT entries.
7309
7310 template<bool big_endian>
7311 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7312                                                      uint64_t addralign,
7313                                                      Output_data_space* got_plt)
7314   : Output_section_data(addralign), got_plt_(got_plt), count_(0)
7315 {
7316   this->rel_ = new Reloc_section(false);
7317   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7318                                   elfcpp::SHF_ALLOC, this->rel_,
7319                                   ORDER_DYNAMIC_PLT_RELOCS, false);
7320 }
7321
7322 template<bool big_endian>
7323 void
7324 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7325 {
7326   os->set_entsize(0);
7327 }
7328
7329 // Add an entry to the PLT.
7330
7331 template<bool big_endian>
7332 void
7333 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7334 {
7335   gold_assert(!gsym->has_plt_offset());
7336
7337   // Note that when setting the PLT offset we skip the initial
7338   // reserved PLT entry.
7339   gsym->set_plt_offset((this->count_) * this->get_plt_entry_size()
7340                        + this->first_plt_entry_offset());
7341
7342   ++this->count_;
7343
7344   section_offset_type got_offset = this->got_plt_->current_data_size();
7345
7346   // Every PLT entry needs a GOT entry which points back to the PLT
7347   // entry (this will be changed by the dynamic linker, normally
7348   // lazily when the function is called).
7349   this->got_plt_->set_current_data_size(got_offset + 4);
7350
7351   // Every PLT entry needs a reloc.
7352   gsym->set_needs_dynsym_entry();
7353   this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7354                          got_offset);
7355
7356   // Note that we don't need to save the symbol.  The contents of the
7357   // PLT are independent of which symbols are used.  The symbols only
7358   // appear in the relocations.
7359 }
7360
7361 template<bool big_endian>
7362 class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
7363 {
7364  public:
7365   Output_data_plt_arm_standard(Layout* layout, Output_data_space* got_plt)
7366     : Output_data_plt_arm<big_endian>(layout, 4, got_plt)
7367   { }
7368
7369  protected:
7370   // Return the offset of the first non-reserved PLT entry.
7371   virtual unsigned int
7372   do_first_plt_entry_offset() const
7373   { return sizeof(first_plt_entry); }
7374
7375   // Return the size of a PLT entry.
7376   virtual unsigned int
7377   do_get_plt_entry_size() const
7378   { return sizeof(plt_entry); }
7379
7380   virtual void
7381   do_fill_first_plt_entry(unsigned char* pov,
7382                           Arm_address got_address,
7383                           Arm_address plt_address);
7384
7385   virtual void
7386   do_fill_plt_entry(unsigned char* pov,
7387                     Arm_address got_address,
7388                     Arm_address plt_address,
7389                     unsigned int got_offset,
7390                     unsigned int plt_offset);
7391
7392  private:
7393   // Template for the first PLT entry.
7394   static const uint32_t first_plt_entry[5];
7395
7396   // Template for subsequent PLT entries.
7397   static const uint32_t plt_entry[3];
7398 };
7399
7400 // ARM PLTs.
7401 // FIXME:  This is not very flexible.  Right now this has only been tested
7402 // on armv5te.  If we are to support additional architecture features like
7403 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7404
7405 // The first entry in the PLT.
7406 template<bool big_endian>
7407 const uint32_t Output_data_plt_arm_standard<big_endian>::first_plt_entry[5] =
7408 {
7409   0xe52de004,   // str   lr, [sp, #-4]!
7410   0xe59fe004,   // ldr   lr, [pc, #4]
7411   0xe08fe00e,   // add   lr, pc, lr
7412   0xe5bef008,   // ldr   pc, [lr, #8]!
7413   0x00000000,   // &GOT[0] - .
7414 };
7415
7416 template<bool big_endian>
7417 void
7418 Output_data_plt_arm_standard<big_endian>::do_fill_first_plt_entry(
7419     unsigned char* pov,
7420     Arm_address got_address,
7421     Arm_address plt_address)
7422 {
7423   // Write first PLT entry.  All but the last word are constants.
7424   const size_t num_first_plt_words = (sizeof(first_plt_entry)
7425                                       / sizeof(plt_entry[0]));
7426   for (size_t i = 0; i < num_first_plt_words - 1; i++)
7427     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7428   // Last word in first PLT entry is &GOT[0] - .
7429   elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7430                                          got_address - (plt_address + 16));
7431 }
7432
7433 // Subsequent entries in the PLT.
7434
7435 template<bool big_endian>
7436 const uint32_t Output_data_plt_arm_standard<big_endian>::plt_entry[3] =
7437 {
7438   0xe28fc600,   // add   ip, pc, #0xNN00000
7439   0xe28cca00,   // add   ip, ip, #0xNN000
7440   0xe5bcf000,   // ldr   pc, [ip, #0xNNN]!
7441 };
7442
7443 template<bool big_endian>
7444 void
7445 Output_data_plt_arm_standard<big_endian>::do_fill_plt_entry(
7446     unsigned char* pov,
7447     Arm_address got_address,
7448     Arm_address plt_address,
7449     unsigned int got_offset,
7450     unsigned int plt_offset)
7451 {
7452   int32_t offset = ((got_address + got_offset)
7453                     - (plt_address + plt_offset + 8));
7454
7455   gold_assert(offset >= 0 && offset < 0x0fffffff);
7456   uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7457   elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7458   uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7459   elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7460   uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7461   elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7462 }
7463
7464 // Write out the PLT.  This uses the hand-coded instructions above,
7465 // and adjusts them as needed.  This is all specified by the arm ELF
7466 // Processor Supplement.
7467
7468 template<bool big_endian>
7469 void
7470 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7471 {
7472   const off_t offset = this->offset();
7473   const section_size_type oview_size =
7474     convert_to_section_size_type(this->data_size());
7475   unsigned char* const oview = of->get_output_view(offset, oview_size);
7476
7477   const off_t got_file_offset = this->got_plt_->offset();
7478   const section_size_type got_size =
7479     convert_to_section_size_type(this->got_plt_->data_size());
7480   unsigned char* const got_view = of->get_output_view(got_file_offset,
7481                                                       got_size);
7482   unsigned char* pov = oview;
7483
7484   Arm_address plt_address = this->address();
7485   Arm_address got_address = this->got_plt_->address();
7486
7487   // Write first PLT entry.
7488   this->fill_first_plt_entry(pov, got_address, plt_address);
7489   pov += this->first_plt_entry_offset();
7490
7491   unsigned char* got_pov = got_view;
7492
7493   memset(got_pov, 0, 12);
7494   got_pov += 12;
7495
7496   unsigned int plt_offset = this->first_plt_entry_offset();
7497   unsigned int got_offset = 12;
7498   const unsigned int count = this->count_;
7499   for (unsigned int i = 0;
7500        i < count;
7501        ++i,
7502          pov += this->get_plt_entry_size(),
7503          got_pov += 4,
7504          plt_offset += this->get_plt_entry_size(),
7505          got_offset += 4)
7506     {
7507       // Set and adjust the PLT entry itself.
7508       this->fill_plt_entry(pov, got_address, plt_address,
7509                            got_offset, plt_offset);
7510
7511       // Set the entry in the GOT.
7512       elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7513     }
7514
7515   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7516   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7517
7518   of->write_output_view(offset, oview_size, oview);
7519   of->write_output_view(got_file_offset, got_size, got_view);
7520 }
7521
7522 // Create a PLT entry for a global symbol.
7523
7524 template<bool big_endian>
7525 void
7526 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7527                                        Symbol* gsym)
7528 {
7529   if (gsym->has_plt_offset())
7530     return;
7531
7532   if (this->plt_ == NULL)
7533     {
7534       // Create the GOT sections first.
7535       this->got_section(symtab, layout);
7536
7537       this->plt_ = this->make_data_plt(layout, this->got_plt_);
7538
7539       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7540                                       (elfcpp::SHF_ALLOC
7541                                        | elfcpp::SHF_EXECINSTR),
7542                                       this->plt_, ORDER_PLT, false);
7543     }
7544   this->plt_->add_entry(gsym);
7545 }
7546
7547 // Return the number of entries in the PLT.
7548
7549 template<bool big_endian>
7550 unsigned int
7551 Target_arm<big_endian>::plt_entry_count() const
7552 {
7553   if (this->plt_ == NULL)
7554     return 0;
7555   return this->plt_->entry_count();
7556 }
7557
7558 // Return the offset of the first non-reserved PLT entry.
7559
7560 template<bool big_endian>
7561 unsigned int
7562 Target_arm<big_endian>::first_plt_entry_offset() const
7563 {
7564   return this->plt_->first_plt_entry_offset();
7565 }
7566
7567 // Return the size of each PLT entry.
7568
7569 template<bool big_endian>
7570 unsigned int
7571 Target_arm<big_endian>::plt_entry_size() const
7572 {
7573   return this->plt_->get_plt_entry_size();
7574 }
7575
7576 // Get the section to use for TLS_DESC relocations.
7577
7578 template<bool big_endian>
7579 typename Target_arm<big_endian>::Reloc_section*
7580 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7581 {
7582   return this->plt_section()->rel_tls_desc(layout);
7583 }
7584
7585 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7586
7587 template<bool big_endian>
7588 void
7589 Target_arm<big_endian>::define_tls_base_symbol(
7590     Symbol_table* symtab,
7591     Layout* layout)
7592 {
7593   if (this->tls_base_symbol_defined_)
7594     return;
7595
7596   Output_segment* tls_segment = layout->tls_segment();
7597   if (tls_segment != NULL)
7598     {
7599       bool is_exec = parameters->options().output_is_executable();
7600       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7601                                        Symbol_table::PREDEFINED,
7602                                        tls_segment, 0, 0,
7603                                        elfcpp::STT_TLS,
7604                                        elfcpp::STB_LOCAL,
7605                                        elfcpp::STV_HIDDEN, 0,
7606                                        (is_exec
7607                                         ? Symbol::SEGMENT_END
7608                                         : Symbol::SEGMENT_START),
7609                                        true);
7610     }
7611   this->tls_base_symbol_defined_ = true;
7612 }
7613
7614 // Create a GOT entry for the TLS module index.
7615
7616 template<bool big_endian>
7617 unsigned int
7618 Target_arm<big_endian>::got_mod_index_entry(
7619     Symbol_table* symtab,
7620     Layout* layout,
7621     Sized_relobj_file<32, big_endian>* object)
7622 {
7623   if (this->got_mod_index_offset_ == -1U)
7624     {
7625       gold_assert(symtab != NULL && layout != NULL && object != NULL);
7626       Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7627       unsigned int got_offset;
7628       if (!parameters->doing_static_link())
7629         {
7630           got_offset = got->add_constant(0);
7631           Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7632           rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7633                              got_offset);
7634         }
7635       else
7636         {
7637           // We are doing a static link.  Just mark it as belong to module 1,
7638           // the executable.
7639           got_offset = got->add_constant(1);
7640         }
7641
7642       got->add_constant(0);
7643       this->got_mod_index_offset_ = got_offset;
7644     }
7645   return this->got_mod_index_offset_;
7646 }
7647
7648 // Optimize the TLS relocation type based on what we know about the
7649 // symbol.  IS_FINAL is true if the final address of this symbol is
7650 // known at link time.
7651
7652 template<bool big_endian>
7653 tls::Tls_optimization
7654 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7655 {
7656   // FIXME: Currently we do not do any TLS optimization.
7657   return tls::TLSOPT_NONE;
7658 }
7659
7660 // Get the Reference_flags for a particular relocation.
7661
7662 template<bool big_endian>
7663 int
7664 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
7665 {
7666   switch (r_type)
7667     {
7668     case elfcpp::R_ARM_NONE:
7669     case elfcpp::R_ARM_V4BX:
7670     case elfcpp::R_ARM_GNU_VTENTRY:
7671     case elfcpp::R_ARM_GNU_VTINHERIT:
7672       // No symbol reference.
7673       return 0;
7674
7675     case elfcpp::R_ARM_ABS32:
7676     case elfcpp::R_ARM_ABS16:
7677     case elfcpp::R_ARM_ABS12:
7678     case elfcpp::R_ARM_THM_ABS5:
7679     case elfcpp::R_ARM_ABS8:
7680     case elfcpp::R_ARM_BASE_ABS:
7681     case elfcpp::R_ARM_MOVW_ABS_NC:
7682     case elfcpp::R_ARM_MOVT_ABS:
7683     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7684     case elfcpp::R_ARM_THM_MOVT_ABS:
7685     case elfcpp::R_ARM_ABS32_NOI:
7686       return Symbol::ABSOLUTE_REF;
7687
7688     case elfcpp::R_ARM_REL32:
7689     case elfcpp::R_ARM_LDR_PC_G0:
7690     case elfcpp::R_ARM_SBREL32:
7691     case elfcpp::R_ARM_THM_PC8:
7692     case elfcpp::R_ARM_BASE_PREL:
7693     case elfcpp::R_ARM_MOVW_PREL_NC:
7694     case elfcpp::R_ARM_MOVT_PREL:
7695     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7696     case elfcpp::R_ARM_THM_MOVT_PREL:
7697     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7698     case elfcpp::R_ARM_THM_PC12:
7699     case elfcpp::R_ARM_REL32_NOI:
7700     case elfcpp::R_ARM_ALU_PC_G0_NC:
7701     case elfcpp::R_ARM_ALU_PC_G0:
7702     case elfcpp::R_ARM_ALU_PC_G1_NC:
7703     case elfcpp::R_ARM_ALU_PC_G1:
7704     case elfcpp::R_ARM_ALU_PC_G2:
7705     case elfcpp::R_ARM_LDR_PC_G1:
7706     case elfcpp::R_ARM_LDR_PC_G2:
7707     case elfcpp::R_ARM_LDRS_PC_G0:
7708     case elfcpp::R_ARM_LDRS_PC_G1:
7709     case elfcpp::R_ARM_LDRS_PC_G2:
7710     case elfcpp::R_ARM_LDC_PC_G0:
7711     case elfcpp::R_ARM_LDC_PC_G1:
7712     case elfcpp::R_ARM_LDC_PC_G2:
7713     case elfcpp::R_ARM_ALU_SB_G0_NC:
7714     case elfcpp::R_ARM_ALU_SB_G0:
7715     case elfcpp::R_ARM_ALU_SB_G1_NC:
7716     case elfcpp::R_ARM_ALU_SB_G1:
7717     case elfcpp::R_ARM_ALU_SB_G2:
7718     case elfcpp::R_ARM_LDR_SB_G0:
7719     case elfcpp::R_ARM_LDR_SB_G1:
7720     case elfcpp::R_ARM_LDR_SB_G2:
7721     case elfcpp::R_ARM_LDRS_SB_G0:
7722     case elfcpp::R_ARM_LDRS_SB_G1:
7723     case elfcpp::R_ARM_LDRS_SB_G2:
7724     case elfcpp::R_ARM_LDC_SB_G0:
7725     case elfcpp::R_ARM_LDC_SB_G1:
7726     case elfcpp::R_ARM_LDC_SB_G2:
7727     case elfcpp::R_ARM_MOVW_BREL_NC:
7728     case elfcpp::R_ARM_MOVT_BREL:
7729     case elfcpp::R_ARM_MOVW_BREL:
7730     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7731     case elfcpp::R_ARM_THM_MOVT_BREL:
7732     case elfcpp::R_ARM_THM_MOVW_BREL:
7733     case elfcpp::R_ARM_GOTOFF32:
7734     case elfcpp::R_ARM_GOTOFF12:
7735     case elfcpp::R_ARM_SBREL31:
7736       return Symbol::RELATIVE_REF;
7737
7738     case elfcpp::R_ARM_PLT32:
7739     case elfcpp::R_ARM_CALL:
7740     case elfcpp::R_ARM_JUMP24:
7741     case elfcpp::R_ARM_THM_CALL:
7742     case elfcpp::R_ARM_THM_JUMP24:
7743     case elfcpp::R_ARM_THM_JUMP19:
7744     case elfcpp::R_ARM_THM_JUMP6:
7745     case elfcpp::R_ARM_THM_JUMP11:
7746     case elfcpp::R_ARM_THM_JUMP8:
7747     // R_ARM_PREL31 is not used to relocate call/jump instructions but
7748     // in unwind tables. It may point to functions via PLTs.
7749     // So we treat it like call/jump relocations above.
7750     case elfcpp::R_ARM_PREL31:
7751       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
7752
7753     case elfcpp::R_ARM_GOT_BREL:
7754     case elfcpp::R_ARM_GOT_ABS:
7755     case elfcpp::R_ARM_GOT_PREL:
7756       // Absolute in GOT.
7757       return Symbol::ABSOLUTE_REF;
7758
7759     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
7760     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
7761     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
7762     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
7763     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
7764       return Symbol::TLS_REF;
7765
7766     case elfcpp::R_ARM_TARGET1:
7767     case elfcpp::R_ARM_TARGET2:
7768     case elfcpp::R_ARM_COPY:
7769     case elfcpp::R_ARM_GLOB_DAT:
7770     case elfcpp::R_ARM_JUMP_SLOT:
7771     case elfcpp::R_ARM_RELATIVE:
7772     case elfcpp::R_ARM_PC24:
7773     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7774     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7775     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7776     default:
7777       // Not expected.  We will give an error later.
7778       return 0;
7779     }
7780 }
7781
7782 // Report an unsupported relocation against a local symbol.
7783
7784 template<bool big_endian>
7785 void
7786 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7787     Sized_relobj_file<32, big_endian>* object,
7788     unsigned int r_type)
7789 {
7790   gold_error(_("%s: unsupported reloc %u against local symbol"),
7791              object->name().c_str(), r_type);
7792 }
7793
7794 // We are about to emit a dynamic relocation of type R_TYPE.  If the
7795 // dynamic linker does not support it, issue an error.  The GNU linker
7796 // only issues a non-PIC error for an allocated read-only section.
7797 // Here we know the section is allocated, but we don't know that it is
7798 // read-only.  But we check for all the relocation types which the
7799 // glibc dynamic linker supports, so it seems appropriate to issue an
7800 // error even if the section is not read-only.
7801
7802 template<bool big_endian>
7803 void
7804 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7805                                             unsigned int r_type)
7806 {
7807   switch (r_type)
7808     {
7809     // These are the relocation types supported by glibc for ARM.
7810     case elfcpp::R_ARM_RELATIVE:
7811     case elfcpp::R_ARM_COPY:
7812     case elfcpp::R_ARM_GLOB_DAT:
7813     case elfcpp::R_ARM_JUMP_SLOT:
7814     case elfcpp::R_ARM_ABS32:
7815     case elfcpp::R_ARM_ABS32_NOI:
7816     case elfcpp::R_ARM_PC24:
7817     // FIXME: The following 3 types are not supported by Android's dynamic
7818     // linker.
7819     case elfcpp::R_ARM_TLS_DTPMOD32:
7820     case elfcpp::R_ARM_TLS_DTPOFF32:
7821     case elfcpp::R_ARM_TLS_TPOFF32:
7822       return;
7823
7824     default:
7825       {
7826         // This prevents us from issuing more than one error per reloc
7827         // section.  But we can still wind up issuing more than one
7828         // error per object file.
7829         if (this->issued_non_pic_error_)
7830           return;
7831         const Arm_reloc_property* reloc_property =
7832           arm_reloc_property_table->get_reloc_property(r_type);
7833         gold_assert(reloc_property != NULL);
7834         object->error(_("requires unsupported dynamic reloc %s; "
7835                       "recompile with -fPIC"),
7836                       reloc_property->name().c_str());
7837         this->issued_non_pic_error_ = true;
7838         return;
7839       }
7840
7841     case elfcpp::R_ARM_NONE:
7842       gold_unreachable();
7843     }
7844 }
7845
7846 // Scan a relocation for a local symbol.
7847 // FIXME: This only handles a subset of relocation types used by Android
7848 // on ARM v5te devices.
7849
7850 template<bool big_endian>
7851 inline void
7852 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7853                                     Layout* layout,
7854                                     Target_arm* target,
7855                                     Sized_relobj_file<32, big_endian>* object,
7856                                     unsigned int data_shndx,
7857                                     Output_section* output_section,
7858                                     const elfcpp::Rel<32, big_endian>& reloc,
7859                                     unsigned int r_type,
7860                                     const elfcpp::Sym<32, big_endian>& lsym)
7861 {
7862   r_type = get_real_reloc_type(r_type);
7863   switch (r_type)
7864     {
7865     case elfcpp::R_ARM_NONE:
7866     case elfcpp::R_ARM_V4BX:
7867     case elfcpp::R_ARM_GNU_VTENTRY:
7868     case elfcpp::R_ARM_GNU_VTINHERIT:
7869       break;
7870
7871     case elfcpp::R_ARM_ABS32:
7872     case elfcpp::R_ARM_ABS32_NOI:
7873       // If building a shared library (or a position-independent
7874       // executable), we need to create a dynamic relocation for
7875       // this location. The relocation applied at link time will
7876       // apply the link-time value, so we flag the location with
7877       // an R_ARM_RELATIVE relocation so the dynamic loader can
7878       // relocate it easily.
7879       if (parameters->options().output_is_position_independent())
7880         {
7881           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7882           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7883           // If we are to add more other reloc types than R_ARM_ABS32,
7884           // we need to add check_non_pic(object, r_type) here.
7885           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7886                                       output_section, data_shndx,
7887                                       reloc.get_r_offset());
7888         }
7889       break;
7890
7891     case elfcpp::R_ARM_ABS16:
7892     case elfcpp::R_ARM_ABS12:
7893     case elfcpp::R_ARM_THM_ABS5:
7894     case elfcpp::R_ARM_ABS8:
7895     case elfcpp::R_ARM_BASE_ABS:
7896     case elfcpp::R_ARM_MOVW_ABS_NC:
7897     case elfcpp::R_ARM_MOVT_ABS:
7898     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7899     case elfcpp::R_ARM_THM_MOVT_ABS:
7900       // If building a shared library (or a position-independent
7901       // executable), we need to create a dynamic relocation for
7902       // this location. Because the addend needs to remain in the
7903       // data section, we need to be careful not to apply this
7904       // relocation statically.
7905       if (parameters->options().output_is_position_independent())
7906         {
7907           check_non_pic(object, r_type);
7908           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7909           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7910           if (lsym.get_st_type() != elfcpp::STT_SECTION)
7911             rel_dyn->add_local(object, r_sym, r_type, output_section,
7912                                data_shndx, reloc.get_r_offset());
7913           else
7914             {
7915               gold_assert(lsym.get_st_value() == 0);
7916               unsigned int shndx = lsym.get_st_shndx();
7917               bool is_ordinary;
7918               shndx = object->adjust_sym_shndx(r_sym, shndx,
7919                                                &is_ordinary);
7920               if (!is_ordinary)
7921                 object->error(_("section symbol %u has bad shndx %u"),
7922                               r_sym, shndx);
7923               else
7924                 rel_dyn->add_local_section(object, shndx,
7925                                            r_type, output_section,
7926                                            data_shndx, reloc.get_r_offset());
7927             }
7928         }
7929       break;
7930
7931     case elfcpp::R_ARM_REL32:
7932     case elfcpp::R_ARM_LDR_PC_G0:
7933     case elfcpp::R_ARM_SBREL32:
7934     case elfcpp::R_ARM_THM_CALL:
7935     case elfcpp::R_ARM_THM_PC8:
7936     case elfcpp::R_ARM_BASE_PREL:
7937     case elfcpp::R_ARM_PLT32:
7938     case elfcpp::R_ARM_CALL:
7939     case elfcpp::R_ARM_JUMP24:
7940     case elfcpp::R_ARM_THM_JUMP24:
7941     case elfcpp::R_ARM_SBREL31:
7942     case elfcpp::R_ARM_PREL31:
7943     case elfcpp::R_ARM_MOVW_PREL_NC:
7944     case elfcpp::R_ARM_MOVT_PREL:
7945     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7946     case elfcpp::R_ARM_THM_MOVT_PREL:
7947     case elfcpp::R_ARM_THM_JUMP19:
7948     case elfcpp::R_ARM_THM_JUMP6:
7949     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7950     case elfcpp::R_ARM_THM_PC12:
7951     case elfcpp::R_ARM_REL32_NOI:
7952     case elfcpp::R_ARM_ALU_PC_G0_NC:
7953     case elfcpp::R_ARM_ALU_PC_G0:
7954     case elfcpp::R_ARM_ALU_PC_G1_NC:
7955     case elfcpp::R_ARM_ALU_PC_G1:
7956     case elfcpp::R_ARM_ALU_PC_G2:
7957     case elfcpp::R_ARM_LDR_PC_G1:
7958     case elfcpp::R_ARM_LDR_PC_G2:
7959     case elfcpp::R_ARM_LDRS_PC_G0:
7960     case elfcpp::R_ARM_LDRS_PC_G1:
7961     case elfcpp::R_ARM_LDRS_PC_G2:
7962     case elfcpp::R_ARM_LDC_PC_G0:
7963     case elfcpp::R_ARM_LDC_PC_G1:
7964     case elfcpp::R_ARM_LDC_PC_G2:
7965     case elfcpp::R_ARM_ALU_SB_G0_NC:
7966     case elfcpp::R_ARM_ALU_SB_G0:
7967     case elfcpp::R_ARM_ALU_SB_G1_NC:
7968     case elfcpp::R_ARM_ALU_SB_G1:
7969     case elfcpp::R_ARM_ALU_SB_G2:
7970     case elfcpp::R_ARM_LDR_SB_G0:
7971     case elfcpp::R_ARM_LDR_SB_G1:
7972     case elfcpp::R_ARM_LDR_SB_G2:
7973     case elfcpp::R_ARM_LDRS_SB_G0:
7974     case elfcpp::R_ARM_LDRS_SB_G1:
7975     case elfcpp::R_ARM_LDRS_SB_G2:
7976     case elfcpp::R_ARM_LDC_SB_G0:
7977     case elfcpp::R_ARM_LDC_SB_G1:
7978     case elfcpp::R_ARM_LDC_SB_G2:
7979     case elfcpp::R_ARM_MOVW_BREL_NC:
7980     case elfcpp::R_ARM_MOVT_BREL:
7981     case elfcpp::R_ARM_MOVW_BREL:
7982     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7983     case elfcpp::R_ARM_THM_MOVT_BREL:
7984     case elfcpp::R_ARM_THM_MOVW_BREL:
7985     case elfcpp::R_ARM_THM_JUMP11:
7986     case elfcpp::R_ARM_THM_JUMP8:
7987       // We don't need to do anything for a relative addressing relocation
7988       // against a local symbol if it does not reference the GOT.
7989       break;
7990
7991     case elfcpp::R_ARM_GOTOFF32:
7992     case elfcpp::R_ARM_GOTOFF12:
7993       // We need a GOT section:
7994       target->got_section(symtab, layout);
7995       break;
7996
7997     case elfcpp::R_ARM_GOT_BREL:
7998     case elfcpp::R_ARM_GOT_PREL:
7999       {
8000         // The symbol requires a GOT entry.
8001         Arm_output_data_got<big_endian>* got =
8002           target->got_section(symtab, layout);
8003         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8004         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
8005           {
8006             // If we are generating a shared object, we need to add a
8007             // dynamic RELATIVE relocation for this symbol's GOT entry.
8008             if (parameters->options().output_is_position_independent())
8009               {
8010                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8011                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8012                 rel_dyn->add_local_relative(
8013                     object, r_sym, elfcpp::R_ARM_RELATIVE, got,
8014                     object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
8015               }
8016           }
8017       }
8018       break;
8019
8020     case elfcpp::R_ARM_TARGET1:
8021     case elfcpp::R_ARM_TARGET2:
8022       // This should have been mapped to another type already.
8023       // Fall through.
8024     case elfcpp::R_ARM_COPY:
8025     case elfcpp::R_ARM_GLOB_DAT:
8026     case elfcpp::R_ARM_JUMP_SLOT:
8027     case elfcpp::R_ARM_RELATIVE:
8028       // These are relocations which should only be seen by the
8029       // dynamic linker, and should never be seen here.
8030       gold_error(_("%s: unexpected reloc %u in object file"),
8031                  object->name().c_str(), r_type);
8032       break;
8033
8034
8035       // These are initial TLS relocs, which are expected when
8036       // linking.
8037     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8038     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8039     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8040     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8041     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8042       {
8043         bool output_is_shared = parameters->options().shared();
8044         const tls::Tls_optimization optimized_type
8045             = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
8046                                                          r_type);
8047         switch (r_type)
8048           {
8049           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8050             if (optimized_type == tls::TLSOPT_NONE)
8051               {
8052                 // Create a pair of GOT entries for the module index and
8053                 // dtv-relative offset.
8054                 Arm_output_data_got<big_endian>* got
8055                     = target->got_section(symtab, layout);
8056                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8057                 unsigned int shndx = lsym.get_st_shndx();
8058                 bool is_ordinary;
8059                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
8060                 if (!is_ordinary)
8061                   {
8062                     object->error(_("local symbol %u has bad shndx %u"),
8063                                   r_sym, shndx);
8064                     break;
8065                   }
8066
8067                 if (!parameters->doing_static_link())
8068                   got->add_local_pair_with_rel(object, r_sym, shndx,
8069                                                GOT_TYPE_TLS_PAIR,
8070                                                target->rel_dyn_section(layout),
8071                                                elfcpp::R_ARM_TLS_DTPMOD32);
8072                 else
8073                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
8074                                                       object, r_sym);
8075               }
8076             else
8077               // FIXME: TLS optimization not supported yet.
8078               gold_unreachable();
8079             break;
8080
8081           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
8082             if (optimized_type == tls::TLSOPT_NONE)
8083               {
8084                 // Create a GOT entry for the module index.
8085                 target->got_mod_index_entry(symtab, layout, object);
8086               }
8087             else
8088               // FIXME: TLS optimization not supported yet.
8089               gold_unreachable();
8090             break;
8091
8092           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
8093             break;
8094
8095           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
8096             layout->set_has_static_tls();
8097             if (optimized_type == tls::TLSOPT_NONE)
8098               {
8099                 // Create a GOT entry for the tp-relative offset.
8100                 Arm_output_data_got<big_endian>* got
8101                   = target->got_section(symtab, layout);
8102                 unsigned int r_sym =
8103                    elfcpp::elf_r_sym<32>(reloc.get_r_info());
8104                 if (!parameters->doing_static_link())
8105                     got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
8106                                             target->rel_dyn_section(layout),
8107                                             elfcpp::R_ARM_TLS_TPOFF32);
8108                 else if (!object->local_has_got_offset(r_sym,
8109                                                        GOT_TYPE_TLS_OFFSET))
8110                   {
8111                     got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
8112                     unsigned int got_offset =
8113                       object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
8114                     got->add_static_reloc(got_offset,
8115                                           elfcpp::R_ARM_TLS_TPOFF32, object,
8116                                           r_sym);
8117                   }
8118               }
8119             else
8120               // FIXME: TLS optimization not supported yet.
8121               gold_unreachable();
8122             break;
8123
8124           case elfcpp::R_ARM_TLS_LE32:          // Local-exec
8125             layout->set_has_static_tls();
8126             if (output_is_shared)
8127               {
8128                 // We need to create a dynamic relocation.
8129                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8130                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8131                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8132                 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8133                                    output_section, data_shndx,
8134                                    reloc.get_r_offset());
8135               }
8136             break;
8137
8138           default:
8139             gold_unreachable();
8140           }
8141       }
8142       break;
8143
8144     case elfcpp::R_ARM_PC24:
8145     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8146     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8147     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8148     default:
8149       unsupported_reloc_local(object, r_type);
8150       break;
8151     }
8152 }
8153
8154 // Report an unsupported relocation against a global symbol.
8155
8156 template<bool big_endian>
8157 void
8158 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8159     Sized_relobj_file<32, big_endian>* object,
8160     unsigned int r_type,
8161     Symbol* gsym)
8162 {
8163   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8164              object->name().c_str(), r_type, gsym->demangled_name().c_str());
8165 }
8166
8167 template<bool big_endian>
8168 inline bool
8169 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8170     unsigned int r_type)
8171 {
8172   switch (r_type)
8173     {
8174     case elfcpp::R_ARM_PC24:
8175     case elfcpp::R_ARM_THM_CALL:
8176     case elfcpp::R_ARM_PLT32:
8177     case elfcpp::R_ARM_CALL:
8178     case elfcpp::R_ARM_JUMP24:
8179     case elfcpp::R_ARM_THM_JUMP24:
8180     case elfcpp::R_ARM_SBREL31:
8181     case elfcpp::R_ARM_PREL31:
8182     case elfcpp::R_ARM_THM_JUMP19:
8183     case elfcpp::R_ARM_THM_JUMP6:
8184     case elfcpp::R_ARM_THM_JUMP11:
8185     case elfcpp::R_ARM_THM_JUMP8:
8186       // All the relocations above are branches except SBREL31 and PREL31.
8187       return false;
8188
8189     default:
8190       // Be conservative and assume this is a function pointer.
8191       return true;
8192     }
8193 }
8194
8195 template<bool big_endian>
8196 inline bool
8197 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8198   Symbol_table*,
8199   Layout*,
8200   Target_arm<big_endian>* target,
8201   Sized_relobj_file<32, big_endian>*,
8202   unsigned int,
8203   Output_section*,
8204   const elfcpp::Rel<32, big_endian>&,
8205   unsigned int r_type,
8206   const elfcpp::Sym<32, big_endian>&)
8207 {
8208   r_type = target->get_real_reloc_type(r_type);
8209   return possible_function_pointer_reloc(r_type);
8210 }
8211
8212 template<bool big_endian>
8213 inline bool
8214 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8215   Symbol_table*,
8216   Layout*,
8217   Target_arm<big_endian>* target,
8218   Sized_relobj_file<32, big_endian>*,
8219   unsigned int,
8220   Output_section*,
8221   const elfcpp::Rel<32, big_endian>&,
8222   unsigned int r_type,
8223   Symbol* gsym)
8224 {
8225   // GOT is not a function.
8226   if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8227     return false;
8228
8229   r_type = target->get_real_reloc_type(r_type);
8230   return possible_function_pointer_reloc(r_type);
8231 }
8232
8233 // Scan a relocation for a global symbol.
8234
8235 template<bool big_endian>
8236 inline void
8237 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8238                                      Layout* layout,
8239                                      Target_arm* target,
8240                                      Sized_relobj_file<32, big_endian>* object,
8241                                      unsigned int data_shndx,
8242                                      Output_section* output_section,
8243                                      const elfcpp::Rel<32, big_endian>& reloc,
8244                                      unsigned int r_type,
8245                                      Symbol* gsym)
8246 {
8247   // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8248   // section.  We check here to avoid creating a dynamic reloc against
8249   // _GLOBAL_OFFSET_TABLE_.
8250   if (!target->has_got_section()
8251       && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8252     target->got_section(symtab, layout);
8253
8254   r_type = get_real_reloc_type(r_type);
8255   switch (r_type)
8256     {
8257     case elfcpp::R_ARM_NONE:
8258     case elfcpp::R_ARM_V4BX:
8259     case elfcpp::R_ARM_GNU_VTENTRY:
8260     case elfcpp::R_ARM_GNU_VTINHERIT:
8261       break;
8262
8263     case elfcpp::R_ARM_ABS32:
8264     case elfcpp::R_ARM_ABS16:
8265     case elfcpp::R_ARM_ABS12:
8266     case elfcpp::R_ARM_THM_ABS5:
8267     case elfcpp::R_ARM_ABS8:
8268     case elfcpp::R_ARM_BASE_ABS:
8269     case elfcpp::R_ARM_MOVW_ABS_NC:
8270     case elfcpp::R_ARM_MOVT_ABS:
8271     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8272     case elfcpp::R_ARM_THM_MOVT_ABS:
8273     case elfcpp::R_ARM_ABS32_NOI:
8274       // Absolute addressing relocations.
8275       {
8276         // Make a PLT entry if necessary.
8277         if (this->symbol_needs_plt_entry(gsym))
8278           {
8279             target->make_plt_entry(symtab, layout, gsym);
8280             // Since this is not a PC-relative relocation, we may be
8281             // taking the address of a function. In that case we need to
8282             // set the entry in the dynamic symbol table to the address of
8283             // the PLT entry.
8284             if (gsym->is_from_dynobj() && !parameters->options().shared())
8285               gsym->set_needs_dynsym_value();
8286           }
8287         // Make a dynamic relocation if necessary.
8288         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8289           {
8290             if (gsym->may_need_copy_reloc())
8291               {
8292                 target->copy_reloc(symtab, layout, object,
8293                                    data_shndx, output_section, gsym, reloc);
8294               }
8295             else if ((r_type == elfcpp::R_ARM_ABS32
8296                       || r_type == elfcpp::R_ARM_ABS32_NOI)
8297                      && gsym->can_use_relative_reloc(false))
8298               {
8299                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8300                 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8301                                              output_section, object,
8302                                              data_shndx, reloc.get_r_offset());
8303               }
8304             else
8305               {
8306                 check_non_pic(object, r_type);
8307                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8308                 rel_dyn->add_global(gsym, r_type, output_section, object,
8309                                     data_shndx, reloc.get_r_offset());
8310               }
8311           }
8312       }
8313       break;
8314
8315     case elfcpp::R_ARM_GOTOFF32:
8316     case elfcpp::R_ARM_GOTOFF12:
8317       // We need a GOT section.
8318       target->got_section(symtab, layout);
8319       break;
8320
8321     case elfcpp::R_ARM_REL32:
8322     case elfcpp::R_ARM_LDR_PC_G0:
8323     case elfcpp::R_ARM_SBREL32:
8324     case elfcpp::R_ARM_THM_PC8:
8325     case elfcpp::R_ARM_BASE_PREL:
8326     case elfcpp::R_ARM_MOVW_PREL_NC:
8327     case elfcpp::R_ARM_MOVT_PREL:
8328     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8329     case elfcpp::R_ARM_THM_MOVT_PREL:
8330     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8331     case elfcpp::R_ARM_THM_PC12:
8332     case elfcpp::R_ARM_REL32_NOI:
8333     case elfcpp::R_ARM_ALU_PC_G0_NC:
8334     case elfcpp::R_ARM_ALU_PC_G0:
8335     case elfcpp::R_ARM_ALU_PC_G1_NC:
8336     case elfcpp::R_ARM_ALU_PC_G1:
8337     case elfcpp::R_ARM_ALU_PC_G2:
8338     case elfcpp::R_ARM_LDR_PC_G1:
8339     case elfcpp::R_ARM_LDR_PC_G2:
8340     case elfcpp::R_ARM_LDRS_PC_G0:
8341     case elfcpp::R_ARM_LDRS_PC_G1:
8342     case elfcpp::R_ARM_LDRS_PC_G2:
8343     case elfcpp::R_ARM_LDC_PC_G0:
8344     case elfcpp::R_ARM_LDC_PC_G1:
8345     case elfcpp::R_ARM_LDC_PC_G2:
8346     case elfcpp::R_ARM_ALU_SB_G0_NC:
8347     case elfcpp::R_ARM_ALU_SB_G0:
8348     case elfcpp::R_ARM_ALU_SB_G1_NC:
8349     case elfcpp::R_ARM_ALU_SB_G1:
8350     case elfcpp::R_ARM_ALU_SB_G2:
8351     case elfcpp::R_ARM_LDR_SB_G0:
8352     case elfcpp::R_ARM_LDR_SB_G1:
8353     case elfcpp::R_ARM_LDR_SB_G2:
8354     case elfcpp::R_ARM_LDRS_SB_G0:
8355     case elfcpp::R_ARM_LDRS_SB_G1:
8356     case elfcpp::R_ARM_LDRS_SB_G2:
8357     case elfcpp::R_ARM_LDC_SB_G0:
8358     case elfcpp::R_ARM_LDC_SB_G1:
8359     case elfcpp::R_ARM_LDC_SB_G2:
8360     case elfcpp::R_ARM_MOVW_BREL_NC:
8361     case elfcpp::R_ARM_MOVT_BREL:
8362     case elfcpp::R_ARM_MOVW_BREL:
8363     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8364     case elfcpp::R_ARM_THM_MOVT_BREL:
8365     case elfcpp::R_ARM_THM_MOVW_BREL:
8366       // Relative addressing relocations.
8367       {
8368         // Make a dynamic relocation if necessary.
8369         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8370           {
8371             if (target->may_need_copy_reloc(gsym))
8372               {
8373                 target->copy_reloc(symtab, layout, object,
8374                                    data_shndx, output_section, gsym, reloc);
8375               }
8376             else
8377               {
8378                 check_non_pic(object, r_type);
8379                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8380                 rel_dyn->add_global(gsym, r_type, output_section, object,
8381                                     data_shndx, reloc.get_r_offset());
8382               }
8383           }
8384       }
8385       break;
8386
8387     case elfcpp::R_ARM_THM_CALL:
8388     case elfcpp::R_ARM_PLT32:
8389     case elfcpp::R_ARM_CALL:
8390     case elfcpp::R_ARM_JUMP24:
8391     case elfcpp::R_ARM_THM_JUMP24:
8392     case elfcpp::R_ARM_SBREL31:
8393     case elfcpp::R_ARM_PREL31:
8394     case elfcpp::R_ARM_THM_JUMP19:
8395     case elfcpp::R_ARM_THM_JUMP6:
8396     case elfcpp::R_ARM_THM_JUMP11:
8397     case elfcpp::R_ARM_THM_JUMP8:
8398       // All the relocation above are branches except for the PREL31 ones.
8399       // A PREL31 relocation can point to a personality function in a shared
8400       // library.  In that case we want to use a PLT because we want to
8401       // call the personality routine and the dynamic linkers we care about
8402       // do not support dynamic PREL31 relocations. An REL31 relocation may
8403       // point to a function whose unwinding behaviour is being described but
8404       // we will not mistakenly generate a PLT for that because we should use
8405       // a local section symbol.
8406
8407       // If the symbol is fully resolved, this is just a relative
8408       // local reloc.  Otherwise we need a PLT entry.
8409       if (gsym->final_value_is_known())
8410         break;
8411       // If building a shared library, we can also skip the PLT entry
8412       // if the symbol is defined in the output file and is protected
8413       // or hidden.
8414       if (gsym->is_defined()
8415           && !gsym->is_from_dynobj()
8416           && !gsym->is_preemptible())
8417         break;
8418       target->make_plt_entry(symtab, layout, gsym);
8419       break;
8420
8421     case elfcpp::R_ARM_GOT_BREL:
8422     case elfcpp::R_ARM_GOT_ABS:
8423     case elfcpp::R_ARM_GOT_PREL:
8424       {
8425         // The symbol requires a GOT entry.
8426         Arm_output_data_got<big_endian>* got =
8427           target->got_section(symtab, layout);
8428         if (gsym->final_value_is_known())
8429           got->add_global(gsym, GOT_TYPE_STANDARD);
8430         else
8431           {
8432             // If this symbol is not fully resolved, we need to add a
8433             // GOT entry with a dynamic relocation.
8434             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8435             if (gsym->is_from_dynobj()
8436                 || gsym->is_undefined()
8437                 || gsym->is_preemptible()
8438                 || (gsym->visibility() == elfcpp::STV_PROTECTED
8439                     && parameters->options().shared()))
8440               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8441                                        rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8442             else
8443               {
8444                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
8445                   rel_dyn->add_global_relative(
8446                       gsym, elfcpp::R_ARM_RELATIVE, got,
8447                       gsym->got_offset(GOT_TYPE_STANDARD));
8448               }
8449           }
8450       }
8451       break;
8452
8453     case elfcpp::R_ARM_TARGET1:
8454     case elfcpp::R_ARM_TARGET2:
8455       // These should have been mapped to other types already.
8456       // Fall through.
8457     case elfcpp::R_ARM_COPY:
8458     case elfcpp::R_ARM_GLOB_DAT:
8459     case elfcpp::R_ARM_JUMP_SLOT:
8460     case elfcpp::R_ARM_RELATIVE:
8461       // These are relocations which should only be seen by the
8462       // dynamic linker, and should never be seen here.
8463       gold_error(_("%s: unexpected reloc %u in object file"),
8464                  object->name().c_str(), r_type);
8465       break;
8466
8467       // These are initial tls relocs, which are expected when
8468       // linking.
8469     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8470     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8471     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8472     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8473     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8474       {
8475         const bool is_final = gsym->final_value_is_known();
8476         const tls::Tls_optimization optimized_type
8477             = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8478         switch (r_type)
8479           {
8480           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8481             if (optimized_type == tls::TLSOPT_NONE)
8482               {
8483                 // Create a pair of GOT entries for the module index and
8484                 // dtv-relative offset.
8485                 Arm_output_data_got<big_endian>* got
8486                     = target->got_section(symtab, layout);
8487                 if (!parameters->doing_static_link())
8488                   got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8489                                                 target->rel_dyn_section(layout),
8490                                                 elfcpp::R_ARM_TLS_DTPMOD32,
8491                                                 elfcpp::R_ARM_TLS_DTPOFF32);
8492                 else
8493                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8494               }
8495             else
8496               // FIXME: TLS optimization not supported yet.
8497               gold_unreachable();
8498             break;
8499
8500           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
8501             if (optimized_type == tls::TLSOPT_NONE)
8502               {
8503                 // Create a GOT entry for the module index.
8504                 target->got_mod_index_entry(symtab, layout, object);
8505               }
8506             else
8507               // FIXME: TLS optimization not supported yet.
8508               gold_unreachable();
8509             break;
8510
8511           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
8512             break;
8513
8514           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
8515             layout->set_has_static_tls();
8516             if (optimized_type == tls::TLSOPT_NONE)
8517               {
8518                 // Create a GOT entry for the tp-relative offset.
8519                 Arm_output_data_got<big_endian>* got
8520                   = target->got_section(symtab, layout);
8521                 if (!parameters->doing_static_link())
8522                   got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
8523                                            target->rel_dyn_section(layout),
8524                                            elfcpp::R_ARM_TLS_TPOFF32);
8525                 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
8526                   {
8527                     got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
8528                     unsigned int got_offset =
8529                        gsym->got_offset(GOT_TYPE_TLS_OFFSET);
8530                     got->add_static_reloc(got_offset,
8531                                           elfcpp::R_ARM_TLS_TPOFF32, gsym);
8532                   }
8533               }
8534             else
8535               // FIXME: TLS optimization not supported yet.
8536               gold_unreachable();
8537             break;
8538
8539           case elfcpp::R_ARM_TLS_LE32:  // Local-exec
8540             layout->set_has_static_tls();
8541             if (parameters->options().shared())
8542               {
8543                 // We need to create a dynamic relocation.
8544                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8545                 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
8546                                     output_section, object,
8547                                     data_shndx, reloc.get_r_offset());
8548               }
8549             break;
8550
8551           default:
8552             gold_unreachable();
8553           }
8554       }
8555       break;
8556
8557     case elfcpp::R_ARM_PC24:
8558     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8559     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8560     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8561     default:
8562       unsupported_reloc_global(object, r_type, gsym);
8563       break;
8564     }
8565 }
8566
8567 // Process relocations for gc.
8568
8569 template<bool big_endian>
8570 void
8571 Target_arm<big_endian>::gc_process_relocs(
8572     Symbol_table* symtab,
8573     Layout* layout,
8574     Sized_relobj_file<32, big_endian>* object,
8575     unsigned int data_shndx,
8576     unsigned int,
8577     const unsigned char* prelocs,
8578     size_t reloc_count,
8579     Output_section* output_section,
8580     bool needs_special_offset_handling,
8581     size_t local_symbol_count,
8582     const unsigned char* plocal_symbols)
8583 {
8584   typedef Target_arm<big_endian> Arm;
8585   typedef typename Target_arm<big_endian>::Scan Scan;
8586
8587   gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
8588                           typename Target_arm::Relocatable_size_for_reloc>(
8589     symtab,
8590     layout,
8591     this,
8592     object,
8593     data_shndx,
8594     prelocs,
8595     reloc_count,
8596     output_section,
8597     needs_special_offset_handling,
8598     local_symbol_count,
8599     plocal_symbols);
8600 }
8601
8602 // Scan relocations for a section.
8603
8604 template<bool big_endian>
8605 void
8606 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
8607                                     Layout* layout,
8608                                     Sized_relobj_file<32, big_endian>* object,
8609                                     unsigned int data_shndx,
8610                                     unsigned int sh_type,
8611                                     const unsigned char* prelocs,
8612                                     size_t reloc_count,
8613                                     Output_section* output_section,
8614                                     bool needs_special_offset_handling,
8615                                     size_t local_symbol_count,
8616                                     const unsigned char* plocal_symbols)
8617 {
8618   typedef typename Target_arm<big_endian>::Scan Scan;
8619   if (sh_type == elfcpp::SHT_RELA)
8620     {
8621       gold_error(_("%s: unsupported RELA reloc section"),
8622                  object->name().c_str());
8623       return;
8624     }
8625
8626   gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
8627     symtab,
8628     layout,
8629     this,
8630     object,
8631     data_shndx,
8632     prelocs,
8633     reloc_count,
8634     output_section,
8635     needs_special_offset_handling,
8636     local_symbol_count,
8637     plocal_symbols);
8638 }
8639
8640 // Finalize the sections.
8641
8642 template<bool big_endian>
8643 void
8644 Target_arm<big_endian>::do_finalize_sections(
8645     Layout* layout,
8646     const Input_objects* input_objects,
8647     Symbol_table*)
8648 {
8649   bool merged_any_attributes = false;
8650   // Merge processor-specific flags.
8651   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
8652        p != input_objects->relobj_end();
8653        ++p)
8654     {
8655       Arm_relobj<big_endian>* arm_relobj =
8656         Arm_relobj<big_endian>::as_arm_relobj(*p);
8657       if (arm_relobj->merge_flags_and_attributes())
8658         {
8659           this->merge_processor_specific_flags(
8660               arm_relobj->name(),
8661               arm_relobj->processor_specific_flags());
8662           this->merge_object_attributes(arm_relobj->name().c_str(),
8663                                         arm_relobj->attributes_section_data());
8664           merged_any_attributes = true;
8665         }
8666     }
8667
8668   for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
8669        p != input_objects->dynobj_end();
8670        ++p)
8671     {
8672       Arm_dynobj<big_endian>* arm_dynobj =
8673         Arm_dynobj<big_endian>::as_arm_dynobj(*p);
8674       this->merge_processor_specific_flags(
8675           arm_dynobj->name(),
8676           arm_dynobj->processor_specific_flags());
8677       this->merge_object_attributes(arm_dynobj->name().c_str(),
8678                                     arm_dynobj->attributes_section_data());
8679       merged_any_attributes = true;
8680     }
8681
8682   // Create an empty uninitialized attribute section if we still don't have it
8683   // at this moment.  This happens if there is no attributes sections in all
8684   // inputs.
8685   if (this->attributes_section_data_ == NULL)
8686     this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
8687
8688   const Object_attribute* cpu_arch_attr =
8689     this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
8690   // Check if we need to use Cortex-A8 workaround.
8691   if (parameters->options().user_set_fix_cortex_a8())
8692     this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
8693   else
8694     {
8695       // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
8696       // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
8697       // profile.
8698       const Object_attribute* cpu_arch_profile_attr =
8699         this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
8700       this->fix_cortex_a8_ =
8701         (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
8702          && (cpu_arch_profile_attr->int_value() == 'A'
8703              || cpu_arch_profile_attr->int_value() == 0));
8704     }
8705
8706   // Check if we can use V4BX interworking.
8707   // The V4BX interworking stub contains BX instruction,
8708   // which is not specified for some profiles.
8709   if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
8710       && !this->may_use_v4t_interworking())
8711     gold_error(_("unable to provide V4BX reloc interworking fix up; "
8712                  "the target profile does not support BX instruction"));
8713
8714   // Fill in some more dynamic tags.
8715   const Reloc_section* rel_plt = (this->plt_ == NULL
8716                                   ? NULL
8717                                   : this->plt_->rel_plt());
8718   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
8719                                   this->rel_dyn_, true, false);
8720
8721   // Emit any relocs we saved in an attempt to avoid generating COPY
8722   // relocs.
8723   if (this->copy_relocs_.any_saved_relocs())
8724     this->copy_relocs_.emit(this->rel_dyn_section(layout));
8725
8726   // Handle the .ARM.exidx section.
8727   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8728
8729   if (!parameters->options().relocatable())
8730     {
8731       if (exidx_section != NULL
8732           && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
8733         {
8734           // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8735           // the .ARM.exidx section.
8736           if (!layout->script_options()->saw_phdrs_clause())
8737             {
8738               gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
8739                                                       0)
8740                           == NULL);
8741               Output_segment*  exidx_segment =
8742                 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8743               exidx_segment->add_output_section_to_nonload(exidx_section,
8744                                                            elfcpp::PF_R);
8745             }
8746         }
8747     }
8748
8749   // Create an .ARM.attributes section if we have merged any attributes
8750   // from inputs.
8751   if (merged_any_attributes)
8752     {
8753       Output_attributes_section_data* attributes_section =
8754       new Output_attributes_section_data(*this->attributes_section_data_);
8755       layout->add_output_section_data(".ARM.attributes",
8756                                       elfcpp::SHT_ARM_ATTRIBUTES, 0,
8757                                       attributes_section, ORDER_INVALID,
8758                                       false);
8759     }
8760
8761   // Fix up links in section EXIDX headers.
8762   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
8763        p != layout->section_list().end();
8764        ++p)
8765     if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
8766       {
8767         Arm_output_section<big_endian>* os =
8768           Arm_output_section<big_endian>::as_arm_output_section(*p);
8769         os->set_exidx_section_link();
8770       }
8771 }
8772
8773 // Return whether a direct absolute static relocation needs to be applied.
8774 // In cases where Scan::local() or Scan::global() has created
8775 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8776 // of the relocation is carried in the data, and we must not
8777 // apply the static relocation.
8778
8779 template<bool big_endian>
8780 inline bool
8781 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8782     const Sized_symbol<32>* gsym,
8783     unsigned int r_type,
8784     bool is_32bit,
8785     Output_section* output_section)
8786 {
8787   // If the output section is not allocated, then we didn't call
8788   // scan_relocs, we didn't create a dynamic reloc, and we must apply
8789   // the reloc here.
8790   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8791       return true;
8792
8793   int ref_flags = Scan::get_reference_flags(r_type);
8794
8795   // For local symbols, we will have created a non-RELATIVE dynamic
8796   // relocation only if (a) the output is position independent,
8797   // (b) the relocation is absolute (not pc- or segment-relative), and
8798   // (c) the relocation is not 32 bits wide.
8799   if (gsym == NULL)
8800     return !(parameters->options().output_is_position_independent()
8801              && (ref_flags & Symbol::ABSOLUTE_REF)
8802              && !is_32bit);
8803
8804   // For global symbols, we use the same helper routines used in the
8805   // scan pass.  If we did not create a dynamic relocation, or if we
8806   // created a RELATIVE dynamic relocation, we should apply the static
8807   // relocation.
8808   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8809   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8810                  && gsym->can_use_relative_reloc(ref_flags
8811                                                  & Symbol::FUNCTION_CALL);
8812   return !has_dyn || is_rel;
8813 }
8814
8815 // Perform a relocation.
8816
8817 template<bool big_endian>
8818 inline bool
8819 Target_arm<big_endian>::Relocate::relocate(
8820     const Relocate_info<32, big_endian>* relinfo,
8821     Target_arm* target,
8822     Output_section* output_section,
8823     size_t relnum,
8824     const elfcpp::Rel<32, big_endian>& rel,
8825     unsigned int r_type,
8826     const Sized_symbol<32>* gsym,
8827     const Symbol_value<32>* psymval,
8828     unsigned char* view,
8829     Arm_address address,
8830     section_size_type view_size)
8831 {
8832   typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8833
8834   r_type = get_real_reloc_type(r_type);
8835   const Arm_reloc_property* reloc_property =
8836     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8837   if (reloc_property == NULL)
8838     {
8839       std::string reloc_name =
8840         arm_reloc_property_table->reloc_name_in_error_message(r_type);
8841       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8842                              _("cannot relocate %s in object file"),
8843                              reloc_name.c_str());
8844       return true;
8845     }
8846
8847   const Arm_relobj<big_endian>* object =
8848     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8849
8850   // If the final branch target of a relocation is THUMB instruction, this
8851   // is 1.  Otherwise it is 0.
8852   Arm_address thumb_bit = 0;
8853   Symbol_value<32> symval;
8854   bool is_weakly_undefined_without_plt = false;
8855   bool have_got_offset = false;
8856   unsigned int got_offset = 0;
8857
8858   // If the relocation uses the GOT entry of a symbol instead of the symbol
8859   // itself, we don't care about whether the symbol is defined or what kind
8860   // of symbol it is.
8861   if (reloc_property->uses_got_entry())
8862     {
8863       // Get the GOT offset.
8864       // The GOT pointer points to the end of the GOT section.
8865       // We need to subtract the size of the GOT section to get
8866       // the actual offset to use in the relocation.
8867       // TODO: We should move GOT offset computing code in TLS relocations
8868       // to here.
8869       switch (r_type)
8870         {
8871         case elfcpp::R_ARM_GOT_BREL:
8872         case elfcpp::R_ARM_GOT_PREL:
8873           if (gsym != NULL)
8874             {
8875               gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8876               got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8877                             - target->got_size());
8878             }
8879           else
8880             {
8881               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8882               gold_assert(object->local_has_got_offset(r_sym,
8883                                                        GOT_TYPE_STANDARD));
8884               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8885                             - target->got_size());
8886             }
8887           have_got_offset = true;
8888           break;
8889
8890         default:
8891           break;
8892         }
8893     }
8894   else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8895     {
8896       if (gsym != NULL)
8897         {
8898           // This is a global symbol.  Determine if we use PLT and if the
8899           // final target is THUMB.
8900           if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
8901             {
8902               // This uses a PLT, change the symbol value.
8903               symval.set_output_value(target->plt_section()->address()
8904                                       + gsym->plt_offset());
8905               psymval = &symval;
8906             }
8907           else if (gsym->is_weak_undefined())
8908             {
8909               // This is a weakly undefined symbol and we do not use PLT
8910               // for this relocation.  A branch targeting this symbol will
8911               // be converted into an NOP.
8912               is_weakly_undefined_without_plt = true;
8913             }
8914           else if (gsym->is_undefined() && reloc_property->uses_symbol())
8915             {
8916               // This relocation uses the symbol value but the symbol is
8917               // undefined.  Exit early and have the caller reporting an
8918               // error.
8919               return true;
8920             }
8921           else
8922             {
8923               // Set thumb bit if symbol:
8924               // -Has type STT_ARM_TFUNC or
8925               // -Has type STT_FUNC, is defined and with LSB in value set.
8926               thumb_bit =
8927                 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8928                  || (gsym->type() == elfcpp::STT_FUNC
8929                      && !gsym->is_undefined()
8930                      && ((psymval->value(object, 0) & 1) != 0)))
8931                 ? 1
8932                 : 0);
8933             }
8934         }
8935       else
8936         {
8937           // This is a local symbol.  Determine if the final target is THUMB.
8938           // We saved this information when all the local symbols were read.
8939           elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8940           unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8941           thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8942         }
8943     }
8944   else
8945     {
8946       // This is a fake relocation synthesized for a stub.  It does not have
8947       // a real symbol.  We just look at the LSB of the symbol value to
8948       // determine if the target is THUMB or not.
8949       thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8950     }
8951
8952   // Strip LSB if this points to a THUMB target.
8953   if (thumb_bit != 0
8954       && reloc_property->uses_thumb_bit()
8955       && ((psymval->value(object, 0) & 1) != 0))
8956     {
8957       Arm_address stripped_value =
8958         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8959       symval.set_output_value(stripped_value);
8960       psymval = &symval;
8961     }
8962
8963   // To look up relocation stubs, we need to pass the symbol table index of
8964   // a local symbol.
8965   unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8966
8967   // Get the addressing origin of the output segment defining the
8968   // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8969   Arm_address sym_origin = 0;
8970   if (reloc_property->uses_symbol_base())
8971     {
8972       if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8973         // R_ARM_BASE_ABS with the NULL symbol will give the
8974         // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8975         // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8976         sym_origin = target->got_plt_section()->address();
8977       else if (gsym == NULL)
8978         sym_origin = 0;
8979       else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8980         sym_origin = gsym->output_segment()->vaddr();
8981       else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
8982         sym_origin = gsym->output_data()->address();
8983
8984       // TODO: Assumes the segment base to be zero for the global symbols
8985       // till the proper support for the segment-base-relative addressing
8986       // will be implemented.  This is consistent with GNU ld.
8987     }
8988
8989   // For relative addressing relocation, find out the relative address base.
8990   Arm_address relative_address_base = 0;
8991   switch(reloc_property->relative_address_base())
8992     {
8993     case Arm_reloc_property::RAB_NONE:
8994     // Relocations with relative address bases RAB_TLS and RAB_tp are
8995     // handled by relocate_tls.  So we do not need to do anything here.
8996     case Arm_reloc_property::RAB_TLS:
8997     case Arm_reloc_property::RAB_tp:
8998       break;
8999     case Arm_reloc_property::RAB_B_S:
9000       relative_address_base = sym_origin;
9001       break;
9002     case Arm_reloc_property::RAB_GOT_ORG:
9003       relative_address_base = target->got_plt_section()->address();
9004       break;
9005     case Arm_reloc_property::RAB_P:
9006       relative_address_base = address;
9007       break;
9008     case Arm_reloc_property::RAB_Pa:
9009       relative_address_base = address & 0xfffffffcU;
9010       break;
9011     default:
9012       gold_unreachable();
9013     }
9014
9015   typename Arm_relocate_functions::Status reloc_status =
9016         Arm_relocate_functions::STATUS_OKAY;
9017   bool check_overflow = reloc_property->checks_overflow();
9018   switch (r_type)
9019     {
9020     case elfcpp::R_ARM_NONE:
9021       break;
9022
9023     case elfcpp::R_ARM_ABS8:
9024       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9025         reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
9026       break;
9027
9028     case elfcpp::R_ARM_ABS12:
9029       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9030         reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
9031       break;
9032
9033     case elfcpp::R_ARM_ABS16:
9034       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9035         reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
9036       break;
9037
9038     case elfcpp::R_ARM_ABS32:
9039       if (should_apply_static_reloc(gsym, r_type, true, output_section))
9040         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9041                                                      thumb_bit);
9042       break;
9043
9044     case elfcpp::R_ARM_ABS32_NOI:
9045       if (should_apply_static_reloc(gsym, r_type, true, output_section))
9046         // No thumb bit for this relocation: (S + A)
9047         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9048                                                      0);
9049       break;
9050
9051     case elfcpp::R_ARM_MOVW_ABS_NC:
9052       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9053         reloc_status = Arm_relocate_functions::movw(view, object, psymval,
9054                                                     0, thumb_bit,
9055                                                     check_overflow);
9056       break;
9057
9058     case elfcpp::R_ARM_MOVT_ABS:
9059       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9060         reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
9061       break;
9062
9063     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9064       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9065         reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
9066                                                         0, thumb_bit, false);
9067       break;
9068
9069     case elfcpp::R_ARM_THM_MOVT_ABS:
9070       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9071         reloc_status = Arm_relocate_functions::thm_movt(view, object,
9072                                                         psymval, 0);
9073       break;
9074
9075     case elfcpp::R_ARM_MOVW_PREL_NC:
9076     case elfcpp::R_ARM_MOVW_BREL_NC:
9077     case elfcpp::R_ARM_MOVW_BREL:
9078       reloc_status =
9079         Arm_relocate_functions::movw(view, object, psymval,
9080                                      relative_address_base, thumb_bit,
9081                                      check_overflow);
9082       break;
9083
9084     case elfcpp::R_ARM_MOVT_PREL:
9085     case elfcpp::R_ARM_MOVT_BREL:
9086       reloc_status =
9087         Arm_relocate_functions::movt(view, object, psymval,
9088                                      relative_address_base);
9089       break;
9090
9091     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9092     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9093     case elfcpp::R_ARM_THM_MOVW_BREL:
9094       reloc_status =
9095         Arm_relocate_functions::thm_movw(view, object, psymval,
9096                                          relative_address_base,
9097                                          thumb_bit, check_overflow);
9098       break;
9099
9100     case elfcpp::R_ARM_THM_MOVT_PREL:
9101     case elfcpp::R_ARM_THM_MOVT_BREL:
9102       reloc_status =
9103         Arm_relocate_functions::thm_movt(view, object, psymval,
9104                                          relative_address_base);
9105       break;
9106
9107     case elfcpp::R_ARM_REL32:
9108       reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9109                                                    address, thumb_bit);
9110       break;
9111
9112     case elfcpp::R_ARM_THM_ABS5:
9113       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9114         reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
9115       break;
9116
9117     // Thumb long branches.
9118     case elfcpp::R_ARM_THM_CALL:
9119     case elfcpp::R_ARM_THM_XPC22:
9120     case elfcpp::R_ARM_THM_JUMP24:
9121       reloc_status =
9122         Arm_relocate_functions::thumb_branch_common(
9123             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9124             thumb_bit, is_weakly_undefined_without_plt);
9125       break;
9126
9127     case elfcpp::R_ARM_GOTOFF32:
9128       {
9129         Arm_address got_origin;
9130         got_origin = target->got_plt_section()->address();
9131         reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9132                                                      got_origin, thumb_bit);
9133       }
9134       break;
9135
9136     case elfcpp::R_ARM_BASE_PREL:
9137       gold_assert(gsym != NULL);
9138       reloc_status =
9139           Arm_relocate_functions::base_prel(view, sym_origin, address);
9140       break;
9141
9142     case elfcpp::R_ARM_BASE_ABS:
9143       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9144         reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
9145       break;
9146
9147     case elfcpp::R_ARM_GOT_BREL:
9148       gold_assert(have_got_offset);
9149       reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
9150       break;
9151
9152     case elfcpp::R_ARM_GOT_PREL:
9153       gold_assert(have_got_offset);
9154       // Get the address origin for GOT PLT, which is allocated right
9155       // after the GOT section, to calculate an absolute address of
9156       // the symbol GOT entry (got_origin + got_offset).
9157       Arm_address got_origin;
9158       got_origin = target->got_plt_section()->address();
9159       reloc_status = Arm_relocate_functions::got_prel(view,
9160                                                       got_origin + got_offset,
9161                                                       address);
9162       break;
9163
9164     case elfcpp::R_ARM_PLT32:
9165     case elfcpp::R_ARM_CALL:
9166     case elfcpp::R_ARM_JUMP24:
9167     case elfcpp::R_ARM_XPC25:
9168       gold_assert(gsym == NULL
9169                   || gsym->has_plt_offset()
9170                   || gsym->final_value_is_known()
9171                   || (gsym->is_defined()
9172                       && !gsym->is_from_dynobj()
9173                       && !gsym->is_preemptible()));
9174       reloc_status =
9175         Arm_relocate_functions::arm_branch_common(
9176             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9177             thumb_bit, is_weakly_undefined_without_plt);
9178       break;
9179
9180     case elfcpp::R_ARM_THM_JUMP19:
9181       reloc_status =
9182         Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9183                                            thumb_bit);
9184       break;
9185
9186     case elfcpp::R_ARM_THM_JUMP6:
9187       reloc_status =
9188         Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9189       break;
9190
9191     case elfcpp::R_ARM_THM_JUMP8:
9192       reloc_status =
9193         Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9194       break;
9195
9196     case elfcpp::R_ARM_THM_JUMP11:
9197       reloc_status =
9198         Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9199       break;
9200
9201     case elfcpp::R_ARM_PREL31:
9202       reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9203                                                     address, thumb_bit);
9204       break;
9205
9206     case elfcpp::R_ARM_V4BX:
9207       if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9208         {
9209           const bool is_v4bx_interworking =
9210               (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9211           reloc_status =
9212             Arm_relocate_functions::v4bx(relinfo, view, object, address,
9213                                          is_v4bx_interworking);
9214         }
9215       break;
9216
9217     case elfcpp::R_ARM_THM_PC8:
9218       reloc_status =
9219         Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9220       break;
9221
9222     case elfcpp::R_ARM_THM_PC12:
9223       reloc_status =
9224         Arm_relocate_functions::thm_pc12(view, object, psymval, address);
9225       break;
9226
9227     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9228       reloc_status =
9229         Arm_relocate_functions::thm_alu11(view, object, psymval, address,
9230                                           thumb_bit);
9231       break;
9232
9233     case elfcpp::R_ARM_ALU_PC_G0_NC:
9234     case elfcpp::R_ARM_ALU_PC_G0:
9235     case elfcpp::R_ARM_ALU_PC_G1_NC:
9236     case elfcpp::R_ARM_ALU_PC_G1:
9237     case elfcpp::R_ARM_ALU_PC_G2:
9238     case elfcpp::R_ARM_ALU_SB_G0_NC:
9239     case elfcpp::R_ARM_ALU_SB_G0:
9240     case elfcpp::R_ARM_ALU_SB_G1_NC:
9241     case elfcpp::R_ARM_ALU_SB_G1:
9242     case elfcpp::R_ARM_ALU_SB_G2:
9243       reloc_status =
9244         Arm_relocate_functions::arm_grp_alu(view, object, psymval,
9245                                             reloc_property->group_index(),
9246                                             relative_address_base,
9247                                             thumb_bit, check_overflow);
9248       break;
9249
9250     case elfcpp::R_ARM_LDR_PC_G0:
9251     case elfcpp::R_ARM_LDR_PC_G1:
9252     case elfcpp::R_ARM_LDR_PC_G2:
9253     case elfcpp::R_ARM_LDR_SB_G0:
9254     case elfcpp::R_ARM_LDR_SB_G1:
9255     case elfcpp::R_ARM_LDR_SB_G2:
9256       reloc_status =
9257           Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9258                                               reloc_property->group_index(),
9259                                               relative_address_base);
9260       break;
9261
9262     case elfcpp::R_ARM_LDRS_PC_G0:
9263     case elfcpp::R_ARM_LDRS_PC_G1:
9264     case elfcpp::R_ARM_LDRS_PC_G2:
9265     case elfcpp::R_ARM_LDRS_SB_G0:
9266     case elfcpp::R_ARM_LDRS_SB_G1:
9267     case elfcpp::R_ARM_LDRS_SB_G2:
9268       reloc_status =
9269           Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9270                                                reloc_property->group_index(),
9271                                                relative_address_base);
9272       break;
9273
9274     case elfcpp::R_ARM_LDC_PC_G0:
9275     case elfcpp::R_ARM_LDC_PC_G1:
9276     case elfcpp::R_ARM_LDC_PC_G2:
9277     case elfcpp::R_ARM_LDC_SB_G0:
9278     case elfcpp::R_ARM_LDC_SB_G1:
9279     case elfcpp::R_ARM_LDC_SB_G2:
9280       reloc_status =
9281           Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9282                                               reloc_property->group_index(),
9283                                               relative_address_base);
9284       break;
9285
9286       // These are initial tls relocs, which are expected when
9287       // linking.
9288     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9289     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9290     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9291     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9292     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9293       reloc_status =
9294         this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9295                            view, address, view_size);
9296       break;
9297
9298     // The known and unknown unsupported and/or deprecated relocations.
9299     case elfcpp::R_ARM_PC24:
9300     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9301     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9302     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9303     default:
9304       // Just silently leave the method. We should get an appropriate error
9305       // message in the scan methods.
9306       break;
9307     }
9308
9309   // Report any errors.
9310   switch (reloc_status)
9311     {
9312     case Arm_relocate_functions::STATUS_OKAY:
9313       break;
9314     case Arm_relocate_functions::STATUS_OVERFLOW:
9315       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9316                              _("relocation overflow in %s"),
9317                              reloc_property->name().c_str());
9318       break;
9319     case Arm_relocate_functions::STATUS_BAD_RELOC:
9320       gold_error_at_location(
9321         relinfo,
9322         relnum,
9323         rel.get_r_offset(),
9324         _("unexpected opcode while processing relocation %s"),
9325         reloc_property->name().c_str());
9326       break;
9327     default:
9328       gold_unreachable();
9329     }
9330
9331   return true;
9332 }
9333
9334 // Perform a TLS relocation.
9335
9336 template<bool big_endian>
9337 inline typename Arm_relocate_functions<big_endian>::Status
9338 Target_arm<big_endian>::Relocate::relocate_tls(
9339     const Relocate_info<32, big_endian>* relinfo,
9340     Target_arm<big_endian>* target,
9341     size_t relnum,
9342     const elfcpp::Rel<32, big_endian>& rel,
9343     unsigned int r_type,
9344     const Sized_symbol<32>* gsym,
9345     const Symbol_value<32>* psymval,
9346     unsigned char* view,
9347     elfcpp::Elf_types<32>::Elf_Addr address,
9348     section_size_type /*view_size*/ )
9349 {
9350   typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9351   typedef Relocate_functions<32, big_endian> RelocFuncs;
9352   Output_segment* tls_segment = relinfo->layout->tls_segment();
9353
9354   const Sized_relobj_file<32, big_endian>* object = relinfo->object;
9355
9356   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9357
9358   const bool is_final = (gsym == NULL
9359                          ? !parameters->options().shared()
9360                          : gsym->final_value_is_known());
9361   const tls::Tls_optimization optimized_type
9362       = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9363   switch (r_type)
9364     {
9365     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9366         {
9367           unsigned int got_type = GOT_TYPE_TLS_PAIR;
9368           unsigned int got_offset;
9369           if (gsym != NULL)
9370             {
9371               gold_assert(gsym->has_got_offset(got_type));
9372               got_offset = gsym->got_offset(got_type) - target->got_size();
9373             }
9374           else
9375             {
9376               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9377               gold_assert(object->local_has_got_offset(r_sym, got_type));
9378               got_offset = (object->local_got_offset(r_sym, got_type)
9379                             - target->got_size());
9380             }
9381           if (optimized_type == tls::TLSOPT_NONE)
9382             {
9383               Arm_address got_entry =
9384                 target->got_plt_section()->address() + got_offset;
9385
9386               // Relocate the field with the PC relative offset of the pair of
9387               // GOT entries.
9388               RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9389               return ArmRelocFuncs::STATUS_OKAY;
9390             }
9391         }
9392       break;
9393
9394     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9395       if (optimized_type == tls::TLSOPT_NONE)
9396         {
9397           // Relocate the field with the offset of the GOT entry for
9398           // the module index.
9399           unsigned int got_offset;
9400           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9401                         - target->got_size());
9402           Arm_address got_entry =
9403             target->got_plt_section()->address() + got_offset;
9404
9405           // Relocate the field with the PC relative offset of the pair of
9406           // GOT entries.
9407           RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9408           return ArmRelocFuncs::STATUS_OKAY;
9409         }
9410       break;
9411
9412     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9413       RelocFuncs::rel32_unaligned(view, value);
9414       return ArmRelocFuncs::STATUS_OKAY;
9415
9416     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9417       if (optimized_type == tls::TLSOPT_NONE)
9418         {
9419           // Relocate the field with the offset of the GOT entry for
9420           // the tp-relative offset of the symbol.
9421           unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9422           unsigned int got_offset;
9423           if (gsym != NULL)
9424             {
9425               gold_assert(gsym->has_got_offset(got_type));
9426               got_offset = gsym->got_offset(got_type);
9427             }
9428           else
9429             {
9430               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9431               gold_assert(object->local_has_got_offset(r_sym, got_type));
9432               got_offset = object->local_got_offset(r_sym, got_type);
9433             }
9434
9435           // All GOT offsets are relative to the end of the GOT.
9436           got_offset -= target->got_size();
9437
9438           Arm_address got_entry =
9439             target->got_plt_section()->address() + got_offset;
9440
9441           // Relocate the field with the PC relative offset of the GOT entry.
9442           RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9443           return ArmRelocFuncs::STATUS_OKAY;
9444         }
9445       break;
9446
9447     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9448       // If we're creating a shared library, a dynamic relocation will
9449       // have been created for this location, so do not apply it now.
9450       if (!parameters->options().shared())
9451         {
9452           gold_assert(tls_segment != NULL);
9453
9454           // $tp points to the TCB, which is followed by the TLS, so we
9455           // need to add TCB size to the offset.
9456           Arm_address aligned_tcb_size =
9457             align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9458           RelocFuncs::rel32_unaligned(view, value + aligned_tcb_size);
9459
9460         }
9461       return ArmRelocFuncs::STATUS_OKAY;
9462
9463     default:
9464       gold_unreachable();
9465     }
9466
9467   gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9468                          _("unsupported reloc %u"),
9469                          r_type);
9470   return ArmRelocFuncs::STATUS_BAD_RELOC;
9471 }
9472
9473 // Relocate section data.
9474
9475 template<bool big_endian>
9476 void
9477 Target_arm<big_endian>::relocate_section(
9478     const Relocate_info<32, big_endian>* relinfo,
9479     unsigned int sh_type,
9480     const unsigned char* prelocs,
9481     size_t reloc_count,
9482     Output_section* output_section,
9483     bool needs_special_offset_handling,
9484     unsigned char* view,
9485     Arm_address address,
9486     section_size_type view_size,
9487     const Reloc_symbol_changes* reloc_symbol_changes)
9488 {
9489   typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
9490   gold_assert(sh_type == elfcpp::SHT_REL);
9491
9492   // See if we are relocating a relaxed input section.  If so, the view
9493   // covers the whole output section and we need to adjust accordingly.
9494   if (needs_special_offset_handling)
9495     {
9496       const Output_relaxed_input_section* poris =
9497         output_section->find_relaxed_input_section(relinfo->object,
9498                                                    relinfo->data_shndx);
9499       if (poris != NULL)
9500         {
9501           Arm_address section_address = poris->address();
9502           section_size_type section_size = poris->data_size();
9503
9504           gold_assert((section_address >= address)
9505                       && ((section_address + section_size)
9506                           <= (address + view_size)));
9507
9508           off_t offset = section_address - address;
9509           view += offset;
9510           address += offset;
9511           view_size = section_size;
9512         }
9513     }
9514
9515   gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
9516                          Arm_relocate>(
9517     relinfo,
9518     this,
9519     prelocs,
9520     reloc_count,
9521     output_section,
9522     needs_special_offset_handling,
9523     view,
9524     address,
9525     view_size,
9526     reloc_symbol_changes);
9527 }
9528
9529 // Return the size of a relocation while scanning during a relocatable
9530 // link.
9531
9532 template<bool big_endian>
9533 unsigned int
9534 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
9535     unsigned int r_type,
9536     Relobj* object)
9537 {
9538   r_type = get_real_reloc_type(r_type);
9539   const Arm_reloc_property* arp =
9540       arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9541   if (arp != NULL)
9542     return arp->size();
9543   else
9544     {
9545       std::string reloc_name =
9546         arm_reloc_property_table->reloc_name_in_error_message(r_type);
9547       gold_error(_("%s: unexpected %s in object file"),
9548                  object->name().c_str(), reloc_name.c_str());
9549       return 0;
9550     }
9551 }
9552
9553 // Scan the relocs during a relocatable link.
9554
9555 template<bool big_endian>
9556 void
9557 Target_arm<big_endian>::scan_relocatable_relocs(
9558     Symbol_table* symtab,
9559     Layout* layout,
9560     Sized_relobj_file<32, big_endian>* object,
9561     unsigned int data_shndx,
9562     unsigned int sh_type,
9563     const unsigned char* prelocs,
9564     size_t reloc_count,
9565     Output_section* output_section,
9566     bool needs_special_offset_handling,
9567     size_t local_symbol_count,
9568     const unsigned char* plocal_symbols,
9569     Relocatable_relocs* rr)
9570 {
9571   gold_assert(sh_type == elfcpp::SHT_REL);
9572
9573   typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
9574     Relocatable_size_for_reloc> Scan_relocatable_relocs;
9575
9576   gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
9577       Scan_relocatable_relocs>(
9578     symtab,
9579     layout,
9580     object,
9581     data_shndx,
9582     prelocs,
9583     reloc_count,
9584     output_section,
9585     needs_special_offset_handling,
9586     local_symbol_count,
9587     plocal_symbols,
9588     rr);
9589 }
9590
9591 // Emit relocations for a section.
9592
9593 template<bool big_endian>
9594 void
9595 Target_arm<big_endian>::relocate_relocs(
9596     const Relocate_info<32, big_endian>* relinfo,
9597     unsigned int sh_type,
9598     const unsigned char* prelocs,
9599     size_t reloc_count,
9600     Output_section* output_section,
9601     off_t offset_in_output_section,
9602     const Relocatable_relocs* rr,
9603     unsigned char* view,
9604     Arm_address view_address,
9605     section_size_type view_size,
9606     unsigned char* reloc_view,
9607     section_size_type reloc_view_size)
9608 {
9609   gold_assert(sh_type == elfcpp::SHT_REL);
9610
9611   gold::relocate_relocs<32, big_endian, elfcpp::SHT_REL>(
9612     relinfo,
9613     prelocs,
9614     reloc_count,
9615     output_section,
9616     offset_in_output_section,
9617     rr,
9618     view,
9619     view_address,
9620     view_size,
9621     reloc_view,
9622     reloc_view_size);
9623 }
9624
9625 // Perform target-specific processing in a relocatable link.  This is
9626 // only used if we use the relocation strategy RELOC_SPECIAL.
9627
9628 template<bool big_endian>
9629 void
9630 Target_arm<big_endian>::relocate_special_relocatable(
9631     const Relocate_info<32, big_endian>* relinfo,
9632     unsigned int sh_type,
9633     const unsigned char* preloc_in,
9634     size_t relnum,
9635     Output_section* output_section,
9636     off_t offset_in_output_section,
9637     unsigned char* view,
9638     elfcpp::Elf_types<32>::Elf_Addr view_address,
9639     section_size_type,
9640     unsigned char* preloc_out)
9641 {
9642   // We can only handle REL type relocation sections.
9643   gold_assert(sh_type == elfcpp::SHT_REL);
9644
9645   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
9646   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
9647     Reltype_write;
9648   const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
9649
9650   const Arm_relobj<big_endian>* object =
9651     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9652   const unsigned int local_count = object->local_symbol_count();
9653
9654   Reltype reloc(preloc_in);
9655   Reltype_write reloc_write(preloc_out);
9656
9657   elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
9658   const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9659   const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
9660
9661   const Arm_reloc_property* arp =
9662     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9663   gold_assert(arp != NULL);
9664
9665   // Get the new symbol index.
9666   // We only use RELOC_SPECIAL strategy in local relocations.
9667   gold_assert(r_sym < local_count);
9668
9669   // We are adjusting a section symbol.  We need to find
9670   // the symbol table index of the section symbol for
9671   // the output section corresponding to input section
9672   // in which this symbol is defined.
9673   bool is_ordinary;
9674   unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
9675   gold_assert(is_ordinary);
9676   Output_section* os = object->output_section(shndx);
9677   gold_assert(os != NULL);
9678   gold_assert(os->needs_symtab_index());
9679   unsigned int new_symndx = os->symtab_index();
9680
9681   // Get the new offset--the location in the output section where
9682   // this relocation should be applied.
9683
9684   Arm_address offset = reloc.get_r_offset();
9685   Arm_address new_offset;
9686   if (offset_in_output_section != invalid_address)
9687     new_offset = offset + offset_in_output_section;
9688   else
9689     {
9690       section_offset_type sot_offset =
9691           convert_types<section_offset_type, Arm_address>(offset);
9692       section_offset_type new_sot_offset =
9693           output_section->output_offset(object, relinfo->data_shndx,
9694                                         sot_offset);
9695       gold_assert(new_sot_offset != -1);
9696       new_offset = new_sot_offset;
9697     }
9698
9699   // In an object file, r_offset is an offset within the section.
9700   // In an executable or dynamic object, generated by
9701   // --emit-relocs, r_offset is an absolute address.
9702   if (!parameters->options().relocatable())
9703     {
9704       new_offset += view_address;
9705       if (offset_in_output_section != invalid_address)
9706         new_offset -= offset_in_output_section;
9707     }
9708
9709   reloc_write.put_r_offset(new_offset);
9710   reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
9711
9712   // Handle the reloc addend.
9713   // The relocation uses a section symbol in the input file.
9714   // We are adjusting it to use a section symbol in the output
9715   // file.  The input section symbol refers to some address in
9716   // the input section.  We need the relocation in the output
9717   // file to refer to that same address.  This adjustment to
9718   // the addend is the same calculation we use for a simple
9719   // absolute relocation for the input section symbol.
9720
9721   const Symbol_value<32>* psymval = object->local_symbol(r_sym);
9722
9723   // Handle THUMB bit.
9724   Symbol_value<32> symval;
9725   Arm_address thumb_bit =
9726      object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9727   if (thumb_bit != 0
9728       && arp->uses_thumb_bit()
9729       && ((psymval->value(object, 0) & 1) != 0))
9730     {
9731       Arm_address stripped_value =
9732         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9733       symval.set_output_value(stripped_value);
9734       psymval = &symval;
9735     }
9736
9737   unsigned char* paddend = view + offset;
9738   typename Arm_relocate_functions<big_endian>::Status reloc_status =
9739         Arm_relocate_functions<big_endian>::STATUS_OKAY;
9740   switch (r_type)
9741     {
9742     case elfcpp::R_ARM_ABS8:
9743       reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
9744                                                               psymval);
9745       break;
9746
9747     case elfcpp::R_ARM_ABS12:
9748       reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
9749                                                                psymval);
9750       break;
9751
9752     case elfcpp::R_ARM_ABS16:
9753       reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
9754                                                                psymval);
9755       break;
9756
9757     case elfcpp::R_ARM_THM_ABS5:
9758       reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
9759                                                                   object,
9760                                                                   psymval);
9761       break;
9762
9763     case elfcpp::R_ARM_MOVW_ABS_NC:
9764     case elfcpp::R_ARM_MOVW_PREL_NC:
9765     case elfcpp::R_ARM_MOVW_BREL_NC:
9766     case elfcpp::R_ARM_MOVW_BREL:
9767       reloc_status = Arm_relocate_functions<big_endian>::movw(
9768           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9769       break;
9770
9771     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9772     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9773     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9774     case elfcpp::R_ARM_THM_MOVW_BREL:
9775       reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
9776           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9777       break;
9778
9779     case elfcpp::R_ARM_THM_CALL:
9780     case elfcpp::R_ARM_THM_XPC22:
9781     case elfcpp::R_ARM_THM_JUMP24:
9782       reloc_status =
9783         Arm_relocate_functions<big_endian>::thumb_branch_common(
9784             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9785             false);
9786       break;
9787
9788     case elfcpp::R_ARM_PLT32:
9789     case elfcpp::R_ARM_CALL:
9790     case elfcpp::R_ARM_JUMP24:
9791     case elfcpp::R_ARM_XPC25:
9792       reloc_status =
9793         Arm_relocate_functions<big_endian>::arm_branch_common(
9794             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9795             false);
9796       break;
9797
9798     case elfcpp::R_ARM_THM_JUMP19:
9799       reloc_status =
9800         Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
9801                                                        psymval, 0, thumb_bit);
9802       break;
9803
9804     case elfcpp::R_ARM_THM_JUMP6:
9805       reloc_status =
9806         Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
9807                                                       0);
9808       break;
9809
9810     case elfcpp::R_ARM_THM_JUMP8:
9811       reloc_status =
9812         Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
9813                                                       0);
9814       break;
9815
9816     case elfcpp::R_ARM_THM_JUMP11:
9817       reloc_status =
9818         Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
9819                                                        0);
9820       break;
9821
9822     case elfcpp::R_ARM_PREL31:
9823       reloc_status =
9824         Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
9825                                                    thumb_bit);
9826       break;
9827
9828     case elfcpp::R_ARM_THM_PC8:
9829       reloc_status =
9830         Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
9831                                                     0);
9832       break;
9833
9834     case elfcpp::R_ARM_THM_PC12:
9835       reloc_status =
9836         Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
9837                                                      0);
9838       break;
9839
9840     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9841       reloc_status =
9842         Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
9843                                                       0, thumb_bit);
9844       break;
9845
9846     // These relocation truncate relocation results so we cannot handle them
9847     // in a relocatable link.
9848     case elfcpp::R_ARM_MOVT_ABS:
9849     case elfcpp::R_ARM_THM_MOVT_ABS:
9850     case elfcpp::R_ARM_MOVT_PREL:
9851     case elfcpp::R_ARM_MOVT_BREL:
9852     case elfcpp::R_ARM_THM_MOVT_PREL:
9853     case elfcpp::R_ARM_THM_MOVT_BREL:
9854     case elfcpp::R_ARM_ALU_PC_G0_NC:
9855     case elfcpp::R_ARM_ALU_PC_G0:
9856     case elfcpp::R_ARM_ALU_PC_G1_NC:
9857     case elfcpp::R_ARM_ALU_PC_G1:
9858     case elfcpp::R_ARM_ALU_PC_G2:
9859     case elfcpp::R_ARM_ALU_SB_G0_NC:
9860     case elfcpp::R_ARM_ALU_SB_G0:
9861     case elfcpp::R_ARM_ALU_SB_G1_NC:
9862     case elfcpp::R_ARM_ALU_SB_G1:
9863     case elfcpp::R_ARM_ALU_SB_G2:
9864     case elfcpp::R_ARM_LDR_PC_G0:
9865     case elfcpp::R_ARM_LDR_PC_G1:
9866     case elfcpp::R_ARM_LDR_PC_G2:
9867     case elfcpp::R_ARM_LDR_SB_G0:
9868     case elfcpp::R_ARM_LDR_SB_G1:
9869     case elfcpp::R_ARM_LDR_SB_G2:
9870     case elfcpp::R_ARM_LDRS_PC_G0:
9871     case elfcpp::R_ARM_LDRS_PC_G1:
9872     case elfcpp::R_ARM_LDRS_PC_G2:
9873     case elfcpp::R_ARM_LDRS_SB_G0:
9874     case elfcpp::R_ARM_LDRS_SB_G1:
9875     case elfcpp::R_ARM_LDRS_SB_G2:
9876     case elfcpp::R_ARM_LDC_PC_G0:
9877     case elfcpp::R_ARM_LDC_PC_G1:
9878     case elfcpp::R_ARM_LDC_PC_G2:
9879     case elfcpp::R_ARM_LDC_SB_G0:
9880     case elfcpp::R_ARM_LDC_SB_G1:
9881     case elfcpp::R_ARM_LDC_SB_G2:
9882       gold_error(_("cannot handle %s in a relocatable link"),
9883                  arp->name().c_str());
9884       break;
9885
9886     default:
9887       gold_unreachable();
9888     }
9889
9890   // Report any errors.
9891   switch (reloc_status)
9892     {
9893     case Arm_relocate_functions<big_endian>::STATUS_OKAY:
9894       break;
9895     case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
9896       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9897                              _("relocation overflow in %s"),
9898                              arp->name().c_str());
9899       break;
9900     case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
9901       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9902         _("unexpected opcode while processing relocation %s"),
9903         arp->name().c_str());
9904       break;
9905     default:
9906       gold_unreachable();
9907     }
9908 }
9909
9910 // Return the value to use for a dynamic symbol which requires special
9911 // treatment.  This is how we support equality comparisons of function
9912 // pointers across shared library boundaries, as described in the
9913 // processor specific ABI supplement.
9914
9915 template<bool big_endian>
9916 uint64_t
9917 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
9918 {
9919   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
9920   return this->plt_section()->address() + gsym->plt_offset();
9921 }
9922
9923 // Map platform-specific relocs to real relocs
9924 //
9925 template<bool big_endian>
9926 unsigned int
9927 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
9928 {
9929   switch (r_type)
9930     {
9931     case elfcpp::R_ARM_TARGET1:
9932       // This is either R_ARM_ABS32 or R_ARM_REL32;
9933       return elfcpp::R_ARM_ABS32;
9934
9935     case elfcpp::R_ARM_TARGET2:
9936       // This can be any reloc type but usually is R_ARM_GOT_PREL
9937       return elfcpp::R_ARM_GOT_PREL;
9938
9939     default:
9940       return r_type;
9941     }
9942 }
9943
9944 // Whether if two EABI versions V1 and V2 are compatible.
9945
9946 template<bool big_endian>
9947 bool
9948 Target_arm<big_endian>::are_eabi_versions_compatible(
9949     elfcpp::Elf_Word v1,
9950     elfcpp::Elf_Word v2)
9951 {
9952   // v4 and v5 are the same spec before and after it was released,
9953   // so allow mixing them.
9954   if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
9955       || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
9956       || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
9957     return true;
9958
9959   return v1 == v2;
9960 }
9961
9962 // Combine FLAGS from an input object called NAME and the processor-specific
9963 // flags in the ELF header of the output.  Much of this is adapted from the
9964 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
9965 // in bfd/elf32-arm.c.
9966
9967 template<bool big_endian>
9968 void
9969 Target_arm<big_endian>::merge_processor_specific_flags(
9970     const std::string& name,
9971     elfcpp::Elf_Word flags)
9972 {
9973   if (this->are_processor_specific_flags_set())
9974     {
9975       elfcpp::Elf_Word out_flags = this->processor_specific_flags();
9976
9977       // Nothing to merge if flags equal to those in output.
9978       if (flags == out_flags)
9979         return;
9980
9981       // Complain about various flag mismatches.
9982       elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
9983       elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
9984       if (!this->are_eabi_versions_compatible(version1, version2)
9985           && parameters->options().warn_mismatch())
9986         gold_error(_("Source object %s has EABI version %d but output has "
9987                      "EABI version %d."),
9988                    name.c_str(),
9989                    (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
9990                    (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
9991     }
9992   else
9993     {
9994       // If the input is the default architecture and had the default
9995       // flags then do not bother setting the flags for the output
9996       // architecture, instead allow future merges to do this.  If no
9997       // future merges ever set these flags then they will retain their
9998       // uninitialised values, which surprise surprise, correspond
9999       // to the default values.
10000       if (flags == 0)
10001         return;
10002
10003       // This is the first time, just copy the flags.
10004       // We only copy the EABI version for now.
10005       this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
10006     }
10007 }
10008
10009 // Adjust ELF file header.
10010 template<bool big_endian>
10011 void
10012 Target_arm<big_endian>::do_adjust_elf_header(
10013     unsigned char* view,
10014     int len) const
10015 {
10016   gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
10017
10018   elfcpp::Ehdr<32, big_endian> ehdr(view);
10019   unsigned char e_ident[elfcpp::EI_NIDENT];
10020   memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
10021
10022   if (elfcpp::arm_eabi_version(this->processor_specific_flags())
10023       == elfcpp::EF_ARM_EABI_UNKNOWN)
10024     e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
10025   else
10026     e_ident[elfcpp::EI_OSABI] = 0;
10027   e_ident[elfcpp::EI_ABIVERSION] = 0;
10028
10029   // FIXME: Do EF_ARM_BE8 adjustment.
10030
10031   elfcpp::Ehdr_write<32, big_endian> oehdr(view);
10032   oehdr.put_e_ident(e_ident);
10033 }
10034
10035 // do_make_elf_object to override the same function in the base class.
10036 // We need to use a target-specific sub-class of
10037 // Sized_relobj_file<32, big_endian> to store ARM specific information.
10038 // Hence we need to have our own ELF object creation.
10039
10040 template<bool big_endian>
10041 Object*
10042 Target_arm<big_endian>::do_make_elf_object(
10043     const std::string& name,
10044     Input_file* input_file,
10045     off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
10046 {
10047   int et = ehdr.get_e_type();
10048   // ET_EXEC files are valid input for --just-symbols/-R,
10049   // and we treat them as relocatable objects.
10050   if (et == elfcpp::ET_REL
10051       || (et == elfcpp::ET_EXEC && input_file->just_symbols()))
10052     {
10053       Arm_relobj<big_endian>* obj =
10054         new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
10055       obj->setup();
10056       return obj;
10057     }
10058   else if (et == elfcpp::ET_DYN)
10059     {
10060       Sized_dynobj<32, big_endian>* obj =
10061         new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
10062       obj->setup();
10063       return obj;
10064     }
10065   else
10066     {
10067       gold_error(_("%s: unsupported ELF file type %d"),
10068                  name.c_str(), et);
10069       return NULL;
10070     }
10071 }
10072
10073 // Read the architecture from the Tag_also_compatible_with attribute, if any.
10074 // Returns -1 if no architecture could be read.
10075 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
10076
10077 template<bool big_endian>
10078 int
10079 Target_arm<big_endian>::get_secondary_compatible_arch(
10080     const Attributes_section_data* pasd)
10081 {
10082   const Object_attribute* known_attributes =
10083     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10084
10085   // Note: the tag and its argument below are uleb128 values, though
10086   // currently-defined values fit in one byte for each.
10087   const std::string& sv =
10088     known_attributes[elfcpp::Tag_also_compatible_with].string_value();
10089   if (sv.size() == 2
10090       && sv.data()[0] == elfcpp::Tag_CPU_arch
10091       && (sv.data()[1] & 128) != 128)
10092    return sv.data()[1];
10093
10094   // This tag is "safely ignorable", so don't complain if it looks funny.
10095   return -1;
10096 }
10097
10098 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10099 // The tag is removed if ARCH is -1.
10100 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10101
10102 template<bool big_endian>
10103 void
10104 Target_arm<big_endian>::set_secondary_compatible_arch(
10105     Attributes_section_data* pasd,
10106     int arch)
10107 {
10108   Object_attribute* known_attributes =
10109     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10110
10111   if (arch == -1)
10112     {
10113       known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10114       return;
10115     }
10116
10117   // Note: the tag and its argument below are uleb128 values, though
10118   // currently-defined values fit in one byte for each.
10119   char sv[3];
10120   sv[0] = elfcpp::Tag_CPU_arch;
10121   gold_assert(arch != 0);
10122   sv[1] = arch;
10123   sv[2] = '\0';
10124
10125   known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10126 }
10127
10128 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10129 // into account.
10130 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10131
10132 template<bool big_endian>
10133 int
10134 Target_arm<big_endian>::tag_cpu_arch_combine(
10135     const char* name,
10136     int oldtag,
10137     int* secondary_compat_out,
10138     int newtag,
10139     int secondary_compat)
10140 {
10141 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10142   static const int v6t2[] =
10143     {
10144       T(V6T2),   // PRE_V4.
10145       T(V6T2),   // V4.
10146       T(V6T2),   // V4T.
10147       T(V6T2),   // V5T.
10148       T(V6T2),   // V5TE.
10149       T(V6T2),   // V5TEJ.
10150       T(V6T2),   // V6.
10151       T(V7),     // V6KZ.
10152       T(V6T2)    // V6T2.
10153     };
10154   static const int v6k[] =
10155     {
10156       T(V6K),    // PRE_V4.
10157       T(V6K),    // V4.
10158       T(V6K),    // V4T.
10159       T(V6K),    // V5T.
10160       T(V6K),    // V5TE.
10161       T(V6K),    // V5TEJ.
10162       T(V6K),    // V6.
10163       T(V6KZ),   // V6KZ.
10164       T(V7),     // V6T2.
10165       T(V6K)     // V6K.
10166     };
10167   static const int v7[] =
10168     {
10169       T(V7),     // PRE_V4.
10170       T(V7),     // V4.
10171       T(V7),     // V4T.
10172       T(V7),     // V5T.
10173       T(V7),     // V5TE.
10174       T(V7),     // V5TEJ.
10175       T(V7),     // V6.
10176       T(V7),     // V6KZ.
10177       T(V7),     // V6T2.
10178       T(V7),     // V6K.
10179       T(V7)      // V7.
10180     };
10181   static const int v6_m[] =
10182     {
10183       -1,        // PRE_V4.
10184       -1,        // V4.
10185       T(V6K),    // V4T.
10186       T(V6K),    // V5T.
10187       T(V6K),    // V5TE.
10188       T(V6K),    // V5TEJ.
10189       T(V6K),    // V6.
10190       T(V6KZ),   // V6KZ.
10191       T(V7),     // V6T2.
10192       T(V6K),    // V6K.
10193       T(V7),     // V7.
10194       T(V6_M)    // V6_M.
10195     };
10196   static const int v6s_m[] =
10197     {
10198       -1,        // PRE_V4.
10199       -1,        // V4.
10200       T(V6K),    // V4T.
10201       T(V6K),    // V5T.
10202       T(V6K),    // V5TE.
10203       T(V6K),    // V5TEJ.
10204       T(V6K),    // V6.
10205       T(V6KZ),   // V6KZ.
10206       T(V7),     // V6T2.
10207       T(V6K),    // V6K.
10208       T(V7),     // V7.
10209       T(V6S_M),  // V6_M.
10210       T(V6S_M)   // V6S_M.
10211     };
10212   static const int v7e_m[] =
10213     {
10214       -1,       // PRE_V4.
10215       -1,       // V4.
10216       T(V7E_M), // V4T.
10217       T(V7E_M), // V5T.
10218       T(V7E_M), // V5TE.
10219       T(V7E_M), // V5TEJ.
10220       T(V7E_M), // V6.
10221       T(V7E_M), // V6KZ.
10222       T(V7E_M), // V6T2.
10223       T(V7E_M), // V6K.
10224       T(V7E_M), // V7.
10225       T(V7E_M), // V6_M.
10226       T(V7E_M), // V6S_M.
10227       T(V7E_M)  // V7E_M.
10228     };
10229   static const int v4t_plus_v6_m[] =
10230     {
10231       -1,               // PRE_V4.
10232       -1,               // V4.
10233       T(V4T),           // V4T.
10234       T(V5T),           // V5T.
10235       T(V5TE),          // V5TE.
10236       T(V5TEJ),         // V5TEJ.
10237       T(V6),            // V6.
10238       T(V6KZ),          // V6KZ.
10239       T(V6T2),          // V6T2.
10240       T(V6K),           // V6K.
10241       T(V7),            // V7.
10242       T(V6_M),          // V6_M.
10243       T(V6S_M),         // V6S_M.
10244       T(V7E_M),         // V7E_M.
10245       T(V4T_PLUS_V6_M)  // V4T plus V6_M.
10246     };
10247   static const int* comb[] =
10248     {
10249       v6t2,
10250       v6k,
10251       v7,
10252       v6_m,
10253       v6s_m,
10254       v7e_m,
10255       // Pseudo-architecture.
10256       v4t_plus_v6_m
10257     };
10258
10259   // Check we've not got a higher architecture than we know about.
10260
10261   if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
10262     {
10263       gold_error(_("%s: unknown CPU architecture"), name);
10264       return -1;
10265     }
10266
10267   // Override old tag if we have a Tag_also_compatible_with on the output.
10268
10269   if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10270       || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10271     oldtag = T(V4T_PLUS_V6_M);
10272
10273   // And override the new tag if we have a Tag_also_compatible_with on the
10274   // input.
10275
10276   if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10277       || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10278     newtag = T(V4T_PLUS_V6_M);
10279
10280   // Architectures before V6KZ add features monotonically.
10281   int tagh = std::max(oldtag, newtag);
10282   if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10283     return tagh;
10284
10285   int tagl = std::min(oldtag, newtag);
10286   int result = comb[tagh - T(V6T2)][tagl];
10287
10288   // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10289   // as the canonical version.
10290   if (result == T(V4T_PLUS_V6_M))
10291     {
10292       result = T(V4T);
10293       *secondary_compat_out = T(V6_M);
10294     }
10295   else
10296     *secondary_compat_out = -1;
10297
10298   if (result == -1)
10299     {
10300       gold_error(_("%s: conflicting CPU architectures %d/%d"),
10301                  name, oldtag, newtag);
10302       return -1;
10303     }
10304
10305   return result;
10306 #undef T
10307 }
10308
10309 // Helper to print AEABI enum tag value.
10310
10311 template<bool big_endian>
10312 std::string
10313 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10314 {
10315   static const char* aeabi_enum_names[] =
10316     { "", "variable-size", "32-bit", "" };
10317   const size_t aeabi_enum_names_size =
10318     sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10319
10320   if (value < aeabi_enum_names_size)
10321     return std::string(aeabi_enum_names[value]);
10322   else
10323     {
10324       char buffer[100];
10325       sprintf(buffer, "<unknown value %u>", value);
10326       return std::string(buffer);
10327     }
10328 }
10329
10330 // Return the string value to store in TAG_CPU_name.
10331
10332 template<bool big_endian>
10333 std::string
10334 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10335 {
10336   static const char* name_table[] = {
10337     // These aren't real CPU names, but we can't guess
10338     // that from the architecture version alone.
10339    "Pre v4",
10340    "ARM v4",
10341    "ARM v4T",
10342    "ARM v5T",
10343    "ARM v5TE",
10344    "ARM v5TEJ",
10345    "ARM v6",
10346    "ARM v6KZ",
10347    "ARM v6T2",
10348    "ARM v6K",
10349    "ARM v7",
10350    "ARM v6-M",
10351    "ARM v6S-M",
10352    "ARM v7E-M"
10353  };
10354  const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10355
10356   if (value < name_table_size)
10357     return std::string(name_table[value]);
10358   else
10359     {
10360       char buffer[100];
10361       sprintf(buffer, "<unknown CPU value %u>", value);
10362       return std::string(buffer);
10363     }
10364 }
10365
10366 // Merge object attributes from input file called NAME with those of the
10367 // output.  The input object attributes are in the object pointed by PASD.
10368
10369 template<bool big_endian>
10370 void
10371 Target_arm<big_endian>::merge_object_attributes(
10372     const char* name,
10373     const Attributes_section_data* pasd)
10374 {
10375   // Return if there is no attributes section data.
10376   if (pasd == NULL)
10377     return;
10378
10379   // If output has no object attributes, just copy.
10380   const int vendor = Object_attribute::OBJ_ATTR_PROC;
10381   if (this->attributes_section_data_ == NULL)
10382     {
10383       this->attributes_section_data_ = new Attributes_section_data(*pasd);
10384       Object_attribute* out_attr =
10385         this->attributes_section_data_->known_attributes(vendor);
10386
10387       // We do not output objects with Tag_MPextension_use_legacy - we move
10388       //  the attribute's value to Tag_MPextension_use.  */
10389       if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10390         {
10391           if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10392               && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10393                 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10394             {
10395               gold_error(_("%s has both the current and legacy "
10396                            "Tag_MPextension_use attributes"),
10397                          name);
10398             }
10399
10400           out_attr[elfcpp::Tag_MPextension_use] =
10401             out_attr[elfcpp::Tag_MPextension_use_legacy];
10402           out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10403           out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10404         }
10405
10406       return;
10407     }
10408
10409   const Object_attribute* in_attr = pasd->known_attributes(vendor);
10410   Object_attribute* out_attr =
10411     this->attributes_section_data_->known_attributes(vendor);
10412
10413   // This needs to happen before Tag_ABI_FP_number_model is merged.  */
10414   if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10415       != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
10416     {
10417       // Ignore mismatches if the object doesn't use floating point.  */
10418       if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
10419         out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10420             in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10421       else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
10422                && parameters->options().warn_mismatch())
10423         gold_error(_("%s uses VFP register arguments, output does not"),
10424                    name);
10425     }
10426
10427   for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10428     {
10429       // Merge this attribute with existing attributes.
10430       switch (i)
10431         {
10432         case elfcpp::Tag_CPU_raw_name:
10433         case elfcpp::Tag_CPU_name:
10434           // These are merged after Tag_CPU_arch.
10435           break;
10436
10437         case elfcpp::Tag_ABI_optimization_goals:
10438         case elfcpp::Tag_ABI_FP_optimization_goals:
10439           // Use the first value seen.
10440           break;
10441
10442         case elfcpp::Tag_CPU_arch:
10443           {
10444             unsigned int saved_out_attr = out_attr->int_value();
10445             // Merge Tag_CPU_arch and Tag_also_compatible_with.
10446             int secondary_compat =
10447               this->get_secondary_compatible_arch(pasd);
10448             int secondary_compat_out =
10449               this->get_secondary_compatible_arch(
10450                   this->attributes_section_data_);
10451             out_attr[i].set_int_value(
10452                 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10453                                      &secondary_compat_out,
10454                                      in_attr[i].int_value(),
10455                                      secondary_compat));
10456             this->set_secondary_compatible_arch(this->attributes_section_data_,
10457                                                 secondary_compat_out);
10458
10459             // Merge Tag_CPU_name and Tag_CPU_raw_name.
10460             if (out_attr[i].int_value() == saved_out_attr)
10461               ; // Leave the names alone.
10462             else if (out_attr[i].int_value() == in_attr[i].int_value())
10463               {
10464                 // The output architecture has been changed to match the
10465                 // input architecture.  Use the input names.
10466                 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10467                     in_attr[elfcpp::Tag_CPU_name].string_value());
10468                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10469                     in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10470               }
10471             else
10472               {
10473                 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10474                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10475               }
10476
10477             // If we still don't have a value for Tag_CPU_name,
10478             // make one up now.  Tag_CPU_raw_name remains blank.
10479             if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10480               {
10481                 const std::string cpu_name =
10482                   this->tag_cpu_name_value(out_attr[i].int_value());
10483                 // FIXME:  If we see an unknown CPU, this will be set
10484                 // to "<unknown CPU n>", where n is the attribute value.
10485                 // This is different from BFD, which leaves the name alone.
10486                 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10487               }
10488           }
10489           break;
10490
10491         case elfcpp::Tag_ARM_ISA_use:
10492         case elfcpp::Tag_THUMB_ISA_use:
10493         case elfcpp::Tag_WMMX_arch:
10494         case elfcpp::Tag_Advanced_SIMD_arch:
10495           // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10496         case elfcpp::Tag_ABI_FP_rounding:
10497         case elfcpp::Tag_ABI_FP_exceptions:
10498         case elfcpp::Tag_ABI_FP_user_exceptions:
10499         case elfcpp::Tag_ABI_FP_number_model:
10500         case elfcpp::Tag_VFP_HP_extension:
10501         case elfcpp::Tag_CPU_unaligned_access:
10502         case elfcpp::Tag_T2EE_use:
10503         case elfcpp::Tag_Virtualization_use:
10504         case elfcpp::Tag_MPextension_use:
10505           // Use the largest value specified.
10506           if (in_attr[i].int_value() > out_attr[i].int_value())
10507             out_attr[i].set_int_value(in_attr[i].int_value());
10508           break;
10509
10510         case elfcpp::Tag_ABI_align8_preserved:
10511         case elfcpp::Tag_ABI_PCS_RO_data:
10512           // Use the smallest value specified.
10513           if (in_attr[i].int_value() < out_attr[i].int_value())
10514             out_attr[i].set_int_value(in_attr[i].int_value());
10515           break;
10516
10517         case elfcpp::Tag_ABI_align8_needed:
10518           if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10519               && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10520                   || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10521                       == 0)))
10522             {
10523               // This error message should be enabled once all non-conforming
10524               // binaries in the toolchain have had the attributes set
10525               // properly.
10526               // gold_error(_("output 8-byte data alignment conflicts with %s"),
10527               //            name);
10528             }
10529           // Fall through.
10530         case elfcpp::Tag_ABI_FP_denormal:
10531         case elfcpp::Tag_ABI_PCS_GOT_use:
10532           {
10533             // These tags have 0 = don't care, 1 = strong requirement,
10534             // 2 = weak requirement.
10535             static const int order_021[3] = {0, 2, 1};
10536
10537             // Use the "greatest" from the sequence 0, 2, 1, or the largest
10538             // value if greater than 2 (for future-proofing).
10539             if ((in_attr[i].int_value() > 2
10540                  && in_attr[i].int_value() > out_attr[i].int_value())
10541                 || (in_attr[i].int_value() <= 2
10542                     && out_attr[i].int_value() <= 2
10543                     && (order_021[in_attr[i].int_value()]
10544                         > order_021[out_attr[i].int_value()])))
10545               out_attr[i].set_int_value(in_attr[i].int_value());
10546           }
10547           break;
10548
10549         case elfcpp::Tag_CPU_arch_profile:
10550           if (out_attr[i].int_value() != in_attr[i].int_value())
10551             {
10552               // 0 will merge with anything.
10553               // 'A' and 'S' merge to 'A'.
10554               // 'R' and 'S' merge to 'R'.
10555               // 'M' and 'A|R|S' is an error.
10556               if (out_attr[i].int_value() == 0
10557                   || (out_attr[i].int_value() == 'S'
10558                       && (in_attr[i].int_value() == 'A'
10559                           || in_attr[i].int_value() == 'R')))
10560                 out_attr[i].set_int_value(in_attr[i].int_value());
10561               else if (in_attr[i].int_value() == 0
10562                        || (in_attr[i].int_value() == 'S'
10563                            && (out_attr[i].int_value() == 'A'
10564                                || out_attr[i].int_value() == 'R')))
10565                 ; // Do nothing.
10566               else if (parameters->options().warn_mismatch())
10567                 {
10568                   gold_error
10569                     (_("conflicting architecture profiles %c/%c"),
10570                      in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10571                      out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10572                 }
10573             }
10574           break;
10575         case elfcpp::Tag_VFP_arch:
10576             {
10577               static const struct
10578               {
10579                   int ver;
10580                   int regs;
10581               } vfp_versions[7] =
10582                 {
10583                   {0, 0},
10584                   {1, 16},
10585                   {2, 16},
10586                   {3, 32},
10587                   {3, 16},
10588                   {4, 32},
10589                   {4, 16}
10590                 };
10591
10592               // Values greater than 6 aren't defined, so just pick the
10593               // biggest.
10594               if (in_attr[i].int_value() > 6
10595                   && in_attr[i].int_value() > out_attr[i].int_value())
10596                 {
10597                   *out_attr = *in_attr;
10598                   break;
10599                 }
10600               // The output uses the superset of input features
10601               // (ISA version) and registers.
10602               int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10603                                  vfp_versions[out_attr[i].int_value()].ver);
10604               int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10605                                   vfp_versions[out_attr[i].int_value()].regs);
10606               // This assumes all possible supersets are also a valid
10607               // options.
10608               int newval;
10609               for (newval = 6; newval > 0; newval--)
10610                 {
10611                   if (regs == vfp_versions[newval].regs
10612                       && ver == vfp_versions[newval].ver)
10613                     break;
10614                 }
10615               out_attr[i].set_int_value(newval);
10616             }
10617           break;
10618         case elfcpp::Tag_PCS_config:
10619           if (out_attr[i].int_value() == 0)
10620             out_attr[i].set_int_value(in_attr[i].int_value());
10621           else if (in_attr[i].int_value() != 0
10622                    && out_attr[i].int_value() != 0
10623                    && parameters->options().warn_mismatch())
10624             {
10625               // It's sometimes ok to mix different configs, so this is only
10626               // a warning.
10627               gold_warning(_("%s: conflicting platform configuration"), name);
10628             }
10629           break;
10630         case elfcpp::Tag_ABI_PCS_R9_use:
10631           if (in_attr[i].int_value() != out_attr[i].int_value()
10632               && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10633               && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10634               && parameters->options().warn_mismatch())
10635             {
10636               gold_error(_("%s: conflicting use of R9"), name);
10637             }
10638           if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10639             out_attr[i].set_int_value(in_attr[i].int_value());
10640           break;
10641         case elfcpp::Tag_ABI_PCS_RW_data:
10642           if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10643               && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10644                   != elfcpp::AEABI_R9_SB)
10645               && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10646                   != elfcpp::AEABI_R9_unused)
10647               && parameters->options().warn_mismatch())
10648             {
10649               gold_error(_("%s: SB relative addressing conflicts with use "
10650                            "of R9"),
10651                            name);
10652             }
10653           // Use the smallest value specified.
10654           if (in_attr[i].int_value() < out_attr[i].int_value())
10655             out_attr[i].set_int_value(in_attr[i].int_value());
10656           break;
10657         case elfcpp::Tag_ABI_PCS_wchar_t:
10658           if (out_attr[i].int_value()
10659               && in_attr[i].int_value()
10660               && out_attr[i].int_value() != in_attr[i].int_value()
10661               && parameters->options().warn_mismatch()
10662               && parameters->options().wchar_size_warning())
10663             {
10664               gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10665                              "use %u-byte wchar_t; use of wchar_t values "
10666                              "across objects may fail"),
10667                            name, in_attr[i].int_value(),
10668                            out_attr[i].int_value());
10669             }
10670           else if (in_attr[i].int_value() && !out_attr[i].int_value())
10671             out_attr[i].set_int_value(in_attr[i].int_value());
10672           break;
10673         case elfcpp::Tag_ABI_enum_size:
10674           if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10675             {
10676               if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10677                   || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10678                 {
10679                   // The existing object is compatible with anything.
10680                   // Use whatever requirements the new object has.
10681                   out_attr[i].set_int_value(in_attr[i].int_value());
10682                 }
10683               else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10684                        && out_attr[i].int_value() != in_attr[i].int_value()
10685                        && parameters->options().warn_mismatch()
10686                        && parameters->options().enum_size_warning())
10687                 {
10688                   unsigned int in_value = in_attr[i].int_value();
10689                   unsigned int out_value = out_attr[i].int_value();
10690                   gold_warning(_("%s uses %s enums yet the output is to use "
10691                                  "%s enums; use of enum values across objects "
10692                                  "may fail"),
10693                                name,
10694                                this->aeabi_enum_name(in_value).c_str(),
10695                                this->aeabi_enum_name(out_value).c_str());
10696                 }
10697             }
10698           break;
10699         case elfcpp::Tag_ABI_VFP_args:
10700           // Already done.
10701           break;
10702         case elfcpp::Tag_ABI_WMMX_args:
10703           if (in_attr[i].int_value() != out_attr[i].int_value()
10704               && parameters->options().warn_mismatch())
10705             {
10706               gold_error(_("%s uses iWMMXt register arguments, output does "
10707                            "not"),
10708                          name);
10709             }
10710           break;
10711         case Object_attribute::Tag_compatibility:
10712           // Merged in target-independent code.
10713           break;
10714         case elfcpp::Tag_ABI_HardFP_use:
10715           // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10716           if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10717               || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10718             out_attr[i].set_int_value(3);
10719           else if (in_attr[i].int_value() > out_attr[i].int_value())
10720             out_attr[i].set_int_value(in_attr[i].int_value());
10721           break;
10722         case elfcpp::Tag_ABI_FP_16bit_format:
10723           if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10724             {
10725               if (in_attr[i].int_value() != out_attr[i].int_value()
10726                   && parameters->options().warn_mismatch())
10727                 gold_error(_("fp16 format mismatch between %s and output"),
10728                            name);
10729             }
10730           if (in_attr[i].int_value() != 0)
10731             out_attr[i].set_int_value(in_attr[i].int_value());
10732           break;
10733
10734         case elfcpp::Tag_DIV_use:
10735           // This tag is set to zero if we can use UDIV and SDIV in Thumb
10736           // mode on a v7-M or v7-R CPU; to one if we can not use UDIV or
10737           // SDIV at all; and to two if we can use UDIV or SDIV on a v7-A
10738           // CPU.  We will merge as follows: If the input attribute's value
10739           // is one then the output attribute's value remains unchanged.  If
10740           // the input attribute's value is zero or two then if the output
10741           // attribute's value is one the output value is set to the input
10742           // value, otherwise the output value must be the same as the
10743           // inputs.  */
10744           if (in_attr[i].int_value() != 1 && out_attr[i].int_value() != 1)
10745             {
10746               if (in_attr[i].int_value() != out_attr[i].int_value())
10747                 {
10748                   gold_error(_("DIV usage mismatch between %s and output"),
10749                              name);
10750                 }
10751             }
10752
10753           if (in_attr[i].int_value() != 1)
10754             out_attr[i].set_int_value(in_attr[i].int_value());
10755
10756           break;
10757
10758         case elfcpp::Tag_MPextension_use_legacy:
10759           // We don't output objects with Tag_MPextension_use_legacy - we
10760           // move the value to Tag_MPextension_use.
10761           if (in_attr[i].int_value() != 0
10762               && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10763             {
10764               if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10765                   != in_attr[i].int_value())
10766                 {
10767                   gold_error(_("%s has has both the current and legacy "
10768                                "Tag_MPextension_use attributes"),
10769                              name);
10770                 }
10771             }
10772
10773           if (in_attr[i].int_value()
10774               > out_attr[elfcpp::Tag_MPextension_use].int_value())
10775             out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10776
10777           break;
10778
10779         case elfcpp::Tag_nodefaults:
10780           // This tag is set if it exists, but the value is unused (and is
10781           // typically zero).  We don't actually need to do anything here -
10782           // the merge happens automatically when the type flags are merged
10783           // below.
10784           break;
10785         case elfcpp::Tag_also_compatible_with:
10786           // Already done in Tag_CPU_arch.
10787           break;
10788         case elfcpp::Tag_conformance:
10789           // Keep the attribute if it matches.  Throw it away otherwise.
10790           // No attribute means no claim to conform.
10791           if (in_attr[i].string_value() != out_attr[i].string_value())
10792             out_attr[i].set_string_value("");
10793           break;
10794
10795         default:
10796           {
10797             const char* err_object = NULL;
10798
10799             // The "known_obj_attributes" table does contain some undefined
10800             // attributes.  Ensure that there are unused.
10801             if (out_attr[i].int_value() != 0
10802                 || out_attr[i].string_value() != "")
10803               err_object = "output";
10804             else if (in_attr[i].int_value() != 0
10805                      || in_attr[i].string_value() != "")
10806               err_object = name;
10807
10808             if (err_object != NULL
10809                 && parameters->options().warn_mismatch())
10810               {
10811                 // Attribute numbers >=64 (mod 128) can be safely ignored.
10812                 if ((i & 127) < 64)
10813                   gold_error(_("%s: unknown mandatory EABI object attribute "
10814                                "%d"),
10815                              err_object, i);
10816                 else
10817                   gold_warning(_("%s: unknown EABI object attribute %d"),
10818                                err_object, i);
10819               }
10820
10821             // Only pass on attributes that match in both inputs.
10822             if (!in_attr[i].matches(out_attr[i]))
10823               {
10824                 out_attr[i].set_int_value(0);
10825                 out_attr[i].set_string_value("");
10826               }
10827           }
10828         }
10829
10830       // If out_attr was copied from in_attr then it won't have a type yet.
10831       if (in_attr[i].type() && !out_attr[i].type())
10832         out_attr[i].set_type(in_attr[i].type());
10833     }
10834
10835   // Merge Tag_compatibility attributes and any common GNU ones.
10836   this->attributes_section_data_->merge(name, pasd);
10837
10838   // Check for any attributes not known on ARM.
10839   typedef Vendor_object_attributes::Other_attributes Other_attributes;
10840   const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10841   Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10842   Other_attributes* out_other_attributes =
10843     this->attributes_section_data_->other_attributes(vendor);
10844   Other_attributes::iterator out_iter = out_other_attributes->begin();
10845
10846   while (in_iter != in_other_attributes->end()
10847          || out_iter != out_other_attributes->end())
10848     {
10849       const char* err_object = NULL;
10850       int err_tag = 0;
10851
10852       // The tags for each list are in numerical order.
10853       // If the tags are equal, then merge.
10854       if (out_iter != out_other_attributes->end()
10855           && (in_iter == in_other_attributes->end()
10856               || in_iter->first > out_iter->first))
10857         {
10858           // This attribute only exists in output.  We can't merge, and we
10859           // don't know what the tag means, so delete it.
10860           err_object = "output";
10861           err_tag = out_iter->first;
10862           int saved_tag = out_iter->first;
10863           delete out_iter->second;
10864           out_other_attributes->erase(out_iter);
10865           out_iter = out_other_attributes->upper_bound(saved_tag);
10866         }
10867       else if (in_iter != in_other_attributes->end()
10868                && (out_iter != out_other_attributes->end()
10869                    || in_iter->first < out_iter->first))
10870         {
10871           // This attribute only exists in input. We can't merge, and we
10872           // don't know what the tag means, so ignore it.
10873           err_object = name;
10874           err_tag = in_iter->first;
10875           ++in_iter;
10876         }
10877       else // The tags are equal.
10878         {
10879           // As present, all attributes in the list are unknown, and
10880           // therefore can't be merged meaningfully.
10881           err_object = "output";
10882           err_tag = out_iter->first;
10883
10884           //  Only pass on attributes that match in both inputs.
10885           if (!in_iter->second->matches(*(out_iter->second)))
10886             {
10887               // No match.  Delete the attribute.
10888               int saved_tag = out_iter->first;
10889               delete out_iter->second;
10890               out_other_attributes->erase(out_iter);
10891               out_iter = out_other_attributes->upper_bound(saved_tag);
10892             }
10893           else
10894             {
10895               // Matched.  Keep the attribute and move to the next.
10896               ++out_iter;
10897               ++in_iter;
10898             }
10899         }
10900
10901       if (err_object && parameters->options().warn_mismatch())
10902         {
10903           // Attribute numbers >=64 (mod 128) can be safely ignored.  */
10904           if ((err_tag & 127) < 64)
10905             {
10906               gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10907                          err_object, err_tag);
10908             }
10909           else
10910             {
10911               gold_warning(_("%s: unknown EABI object attribute %d"),
10912                            err_object, err_tag);
10913             }
10914         }
10915     }
10916 }
10917
10918 // Stub-generation methods for Target_arm.
10919
10920 // Make a new Arm_input_section object.
10921
10922 template<bool big_endian>
10923 Arm_input_section<big_endian>*
10924 Target_arm<big_endian>::new_arm_input_section(
10925     Relobj* relobj,
10926     unsigned int shndx)
10927 {
10928   Section_id sid(relobj, shndx);
10929
10930   Arm_input_section<big_endian>* arm_input_section =
10931     new Arm_input_section<big_endian>(relobj, shndx);
10932   arm_input_section->init();
10933
10934   // Register new Arm_input_section in map for look-up.
10935   std::pair<typename Arm_input_section_map::iterator, bool> ins =
10936     this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
10937
10938   // Make sure that it we have not created another Arm_input_section
10939   // for this input section already.
10940   gold_assert(ins.second);
10941
10942   return arm_input_section;
10943 }
10944
10945 // Find the Arm_input_section object corresponding to the SHNDX-th input
10946 // section of RELOBJ.
10947
10948 template<bool big_endian>
10949 Arm_input_section<big_endian>*
10950 Target_arm<big_endian>::find_arm_input_section(
10951     Relobj* relobj,
10952     unsigned int shndx) const
10953 {
10954   Section_id sid(relobj, shndx);
10955   typename Arm_input_section_map::const_iterator p =
10956     this->arm_input_section_map_.find(sid);
10957   return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
10958 }
10959
10960 // Make a new stub table.
10961
10962 template<bool big_endian>
10963 Stub_table<big_endian>*
10964 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
10965 {
10966   Stub_table<big_endian>* stub_table =
10967     new Stub_table<big_endian>(owner);
10968   this->stub_tables_.push_back(stub_table);
10969
10970   stub_table->set_address(owner->address() + owner->data_size());
10971   stub_table->set_file_offset(owner->offset() + owner->data_size());
10972   stub_table->finalize_data_size();
10973
10974   return stub_table;
10975 }
10976
10977 // Scan a relocation for stub generation.
10978
10979 template<bool big_endian>
10980 void
10981 Target_arm<big_endian>::scan_reloc_for_stub(
10982     const Relocate_info<32, big_endian>* relinfo,
10983     unsigned int r_type,
10984     const Sized_symbol<32>* gsym,
10985     unsigned int r_sym,
10986     const Symbol_value<32>* psymval,
10987     elfcpp::Elf_types<32>::Elf_Swxword addend,
10988     Arm_address address)
10989 {
10990   const Arm_relobj<big_endian>* arm_relobj =
10991     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10992
10993   bool target_is_thumb;
10994   Symbol_value<32> symval;
10995   if (gsym != NULL)
10996     {
10997       // This is a global symbol.  Determine if we use PLT and if the
10998       // final target is THUMB.
10999       if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
11000         {
11001           // This uses a PLT, change the symbol value.
11002           symval.set_output_value(this->plt_section()->address()
11003                                   + gsym->plt_offset());
11004           psymval = &symval;
11005           target_is_thumb = false;
11006         }
11007       else if (gsym->is_undefined())
11008         // There is no need to generate a stub symbol is undefined.
11009         return;
11010       else
11011         {
11012           target_is_thumb =
11013             ((gsym->type() == elfcpp::STT_ARM_TFUNC)
11014              || (gsym->type() == elfcpp::STT_FUNC
11015                  && !gsym->is_undefined()
11016                  && ((psymval->value(arm_relobj, 0) & 1) != 0)));
11017         }
11018     }
11019   else
11020     {
11021       // This is a local symbol.  Determine if the final target is THUMB.
11022       target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
11023     }
11024
11025   // Strip LSB if this points to a THUMB target.
11026   const Arm_reloc_property* reloc_property =
11027     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
11028   gold_assert(reloc_property != NULL);
11029   if (target_is_thumb
11030       && reloc_property->uses_thumb_bit()
11031       && ((psymval->value(arm_relobj, 0) & 1) != 0))
11032     {
11033       Arm_address stripped_value =
11034         psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
11035       symval.set_output_value(stripped_value);
11036       psymval = &symval;
11037     }
11038
11039   // Get the symbol value.
11040   Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
11041
11042   // Owing to pipelining, the PC relative branches below actually skip
11043   // two instructions when the branch offset is 0.
11044   Arm_address destination;
11045   switch (r_type)
11046     {
11047     case elfcpp::R_ARM_CALL:
11048     case elfcpp::R_ARM_JUMP24:
11049     case elfcpp::R_ARM_PLT32:
11050       // ARM branches.
11051       destination = value + addend + 8;
11052       break;
11053     case elfcpp::R_ARM_THM_CALL:
11054     case elfcpp::R_ARM_THM_XPC22:
11055     case elfcpp::R_ARM_THM_JUMP24:
11056     case elfcpp::R_ARM_THM_JUMP19:
11057       // THUMB branches.
11058       destination = value + addend + 4;
11059       break;
11060     default:
11061       gold_unreachable();
11062     }
11063
11064   Reloc_stub* stub = NULL;
11065   Stub_type stub_type =
11066     Reloc_stub::stub_type_for_reloc(r_type, address, destination,
11067                                     target_is_thumb);
11068   if (stub_type != arm_stub_none)
11069     {
11070       // Try looking up an existing stub from a stub table.
11071       Stub_table<big_endian>* stub_table =
11072         arm_relobj->stub_table(relinfo->data_shndx);
11073       gold_assert(stub_table != NULL);
11074
11075       // Locate stub by destination.
11076       Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
11077
11078       // Create a stub if there is not one already
11079       stub = stub_table->find_reloc_stub(stub_key);
11080       if (stub == NULL)
11081         {
11082           // create a new stub and add it to stub table.
11083           stub = this->stub_factory().make_reloc_stub(stub_type);
11084           stub_table->add_reloc_stub(stub, stub_key);
11085         }
11086
11087       // Record the destination address.
11088       stub->set_destination_address(destination
11089                                     | (target_is_thumb ? 1 : 0));
11090     }
11091
11092   // For Cortex-A8, we need to record a relocation at 4K page boundary.
11093   if (this->fix_cortex_a8_
11094       && (r_type == elfcpp::R_ARM_THM_JUMP24
11095           || r_type == elfcpp::R_ARM_THM_JUMP19
11096           || r_type == elfcpp::R_ARM_THM_CALL
11097           || r_type == elfcpp::R_ARM_THM_XPC22)
11098       && (address & 0xfffU) == 0xffeU)
11099     {
11100       // Found a candidate.  Note we haven't checked the destination is
11101       // within 4K here: if we do so (and don't create a record) we can't
11102       // tell that a branch should have been relocated when scanning later.
11103       this->cortex_a8_relocs_info_[address] =
11104         new Cortex_a8_reloc(stub, r_type,
11105                             destination | (target_is_thumb ? 1 : 0));
11106     }
11107 }
11108
11109 // This function scans a relocation sections for stub generation.
11110 // The template parameter Relocate must be a class type which provides
11111 // a single function, relocate(), which implements the machine
11112 // specific part of a relocation.
11113
11114 // BIG_ENDIAN is the endianness of the data.  SH_TYPE is the section type:
11115 // SHT_REL or SHT_RELA.
11116
11117 // PRELOCS points to the relocation data.  RELOC_COUNT is the number
11118 // of relocs.  OUTPUT_SECTION is the output section.
11119 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
11120 // mapped to output offsets.
11121
11122 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
11123 // VIEW_SIZE is the size.  These refer to the input section, unless
11124 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
11125 // the output section.
11126
11127 template<bool big_endian>
11128 template<int sh_type>
11129 void inline
11130 Target_arm<big_endian>::scan_reloc_section_for_stubs(
11131     const Relocate_info<32, big_endian>* relinfo,
11132     const unsigned char* prelocs,
11133     size_t reloc_count,
11134     Output_section* output_section,
11135     bool needs_special_offset_handling,
11136     const unsigned char* view,
11137     elfcpp::Elf_types<32>::Elf_Addr view_address,
11138     section_size_type)
11139 {
11140   typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
11141   const int reloc_size =
11142     Reloc_types<sh_type, 32, big_endian>::reloc_size;
11143
11144   Arm_relobj<big_endian>* arm_object =
11145     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11146   unsigned int local_count = arm_object->local_symbol_count();
11147
11148   Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11149
11150   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11151     {
11152       Reltype reloc(prelocs);
11153
11154       typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11155       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11156       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11157
11158       r_type = this->get_real_reloc_type(r_type);
11159
11160       // Only a few relocation types need stubs.
11161       if ((r_type != elfcpp::R_ARM_CALL)
11162          && (r_type != elfcpp::R_ARM_JUMP24)
11163          && (r_type != elfcpp::R_ARM_PLT32)
11164          && (r_type != elfcpp::R_ARM_THM_CALL)
11165          && (r_type != elfcpp::R_ARM_THM_XPC22)
11166          && (r_type != elfcpp::R_ARM_THM_JUMP24)
11167          && (r_type != elfcpp::R_ARM_THM_JUMP19)
11168          && (r_type != elfcpp::R_ARM_V4BX))
11169         continue;
11170
11171       section_offset_type offset =
11172         convert_to_section_size_type(reloc.get_r_offset());
11173
11174       if (needs_special_offset_handling)
11175         {
11176           offset = output_section->output_offset(relinfo->object,
11177                                                  relinfo->data_shndx,
11178                                                  offset);
11179           if (offset == -1)
11180             continue;
11181         }
11182
11183       // Create a v4bx stub if --fix-v4bx-interworking is used.
11184       if (r_type == elfcpp::R_ARM_V4BX)
11185         {
11186           if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11187             {
11188               // Get the BX instruction.
11189               typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11190               const Valtype* wv =
11191                 reinterpret_cast<const Valtype*>(view + offset);
11192               elfcpp::Elf_types<32>::Elf_Swxword insn =
11193                 elfcpp::Swap<32, big_endian>::readval(wv);
11194               const uint32_t reg = (insn & 0xf);
11195
11196               if (reg < 0xf)
11197                 {
11198                   // Try looking up an existing stub from a stub table.
11199                   Stub_table<big_endian>* stub_table =
11200                     arm_object->stub_table(relinfo->data_shndx);
11201                   gold_assert(stub_table != NULL);
11202
11203                   if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11204                     {
11205                       // create a new stub and add it to stub table.
11206                       Arm_v4bx_stub* stub =
11207                         this->stub_factory().make_arm_v4bx_stub(reg);
11208                       gold_assert(stub != NULL);
11209                       stub_table->add_arm_v4bx_stub(stub);
11210                     }
11211                 }
11212             }
11213           continue;
11214         }
11215
11216       // Get the addend.
11217       Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11218       elfcpp::Elf_types<32>::Elf_Swxword addend =
11219         stub_addend_reader(r_type, view + offset, reloc);
11220
11221       const Sized_symbol<32>* sym;
11222
11223       Symbol_value<32> symval;
11224       const Symbol_value<32> *psymval;
11225       bool is_defined_in_discarded_section;
11226       unsigned int shndx;
11227       if (r_sym < local_count)
11228         {
11229           sym = NULL;
11230           psymval = arm_object->local_symbol(r_sym);
11231
11232           // If the local symbol belongs to a section we are discarding,
11233           // and that section is a debug section, try to find the
11234           // corresponding kept section and map this symbol to its
11235           // counterpart in the kept section.  The symbol must not
11236           // correspond to a section we are folding.
11237           bool is_ordinary;
11238           shndx = psymval->input_shndx(&is_ordinary);
11239           is_defined_in_discarded_section =
11240             (is_ordinary
11241              && shndx != elfcpp::SHN_UNDEF
11242              && !arm_object->is_section_included(shndx)
11243              && !relinfo->symtab->is_section_folded(arm_object, shndx));
11244
11245           // We need to compute the would-be final value of this local
11246           // symbol.
11247           if (!is_defined_in_discarded_section)
11248             {
11249               typedef Sized_relobj_file<32, big_endian> ObjType;
11250               typename ObjType::Compute_final_local_value_status status =
11251                 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11252                                                       relinfo->symtab);
11253               if (status == ObjType::CFLV_OK)
11254                 {
11255                   // Currently we cannot handle a branch to a target in
11256                   // a merged section.  If this is the case, issue an error
11257                   // and also free the merge symbol value.
11258                   if (!symval.has_output_value())
11259                     {
11260                       const std::string& section_name =
11261                         arm_object->section_name(shndx);
11262                       arm_object->error(_("cannot handle branch to local %u "
11263                                           "in a merged section %s"),
11264                                         r_sym, section_name.c_str());
11265                     }
11266                   psymval = &symval;
11267                 }
11268               else
11269                 {
11270                   // We cannot determine the final value.
11271                   continue;
11272                 }
11273             }
11274         }
11275       else
11276         {
11277           const Symbol* gsym;
11278           gsym = arm_object->global_symbol(r_sym);
11279           gold_assert(gsym != NULL);
11280           if (gsym->is_forwarder())
11281             gsym = relinfo->symtab->resolve_forwards(gsym);
11282
11283           sym = static_cast<const Sized_symbol<32>*>(gsym);
11284           if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11285             symval.set_output_symtab_index(sym->symtab_index());
11286           else
11287             symval.set_no_output_symtab_entry();
11288
11289           // We need to compute the would-be final value of this global
11290           // symbol.
11291           const Symbol_table* symtab = relinfo->symtab;
11292           const Sized_symbol<32>* sized_symbol =
11293             symtab->get_sized_symbol<32>(gsym);
11294           Symbol_table::Compute_final_value_status status;
11295           Arm_address value =
11296             symtab->compute_final_value<32>(sized_symbol, &status);
11297
11298           // Skip this if the symbol has not output section.
11299           if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11300             continue;
11301           symval.set_output_value(value);
11302
11303           if (gsym->type() == elfcpp::STT_TLS)
11304             symval.set_is_tls_symbol();
11305           else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11306             symval.set_is_ifunc_symbol();
11307           psymval = &symval;
11308
11309           is_defined_in_discarded_section =
11310             (gsym->is_defined_in_discarded_section()
11311              && gsym->is_undefined());
11312           shndx = 0;
11313         }
11314
11315       Symbol_value<32> symval2;
11316       if (is_defined_in_discarded_section)
11317         {
11318           if (comdat_behavior == CB_UNDETERMINED)
11319             {
11320               std::string name = arm_object->section_name(relinfo->data_shndx);
11321               comdat_behavior = get_comdat_behavior(name.c_str());
11322             }
11323           if (comdat_behavior == CB_PRETEND)
11324             {
11325               // FIXME: This case does not work for global symbols.
11326               // We have no place to store the original section index.
11327               // Fortunately this does not matter for comdat sections,
11328               // only for sections explicitly discarded by a linker
11329               // script.
11330               bool found;
11331               typename elfcpp::Elf_types<32>::Elf_Addr value =
11332                 arm_object->map_to_kept_section(shndx, &found);
11333               if (found)
11334                 symval2.set_output_value(value + psymval->input_value());
11335               else
11336                 symval2.set_output_value(0);
11337             }
11338           else
11339             {
11340               if (comdat_behavior == CB_WARNING)
11341                 gold_warning_at_location(relinfo, i, offset,
11342                                          _("relocation refers to discarded "
11343                                            "section"));
11344               symval2.set_output_value(0);
11345             }
11346           symval2.set_no_output_symtab_entry();
11347           psymval = &symval2;
11348         }
11349
11350       // If symbol is a section symbol, we don't know the actual type of
11351       // destination.  Give up.
11352       if (psymval->is_section_symbol())
11353         continue;
11354
11355       this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11356                                 addend, view_address + offset);
11357     }
11358 }
11359
11360 // Scan an input section for stub generation.
11361
11362 template<bool big_endian>
11363 void
11364 Target_arm<big_endian>::scan_section_for_stubs(
11365     const Relocate_info<32, big_endian>* relinfo,
11366     unsigned int sh_type,
11367     const unsigned char* prelocs,
11368     size_t reloc_count,
11369     Output_section* output_section,
11370     bool needs_special_offset_handling,
11371     const unsigned char* view,
11372     Arm_address view_address,
11373     section_size_type view_size)
11374 {
11375   if (sh_type == elfcpp::SHT_REL)
11376     this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11377         relinfo,
11378         prelocs,
11379         reloc_count,
11380         output_section,
11381         needs_special_offset_handling,
11382         view,
11383         view_address,
11384         view_size);
11385   else if (sh_type == elfcpp::SHT_RELA)
11386     // We do not support RELA type relocations yet.  This is provided for
11387     // completeness.
11388     this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11389         relinfo,
11390         prelocs,
11391         reloc_count,
11392         output_section,
11393         needs_special_offset_handling,
11394         view,
11395         view_address,
11396         view_size);
11397   else
11398     gold_unreachable();
11399 }
11400
11401 // Group input sections for stub generation.
11402 //
11403 // We group input sections in an output section so that the total size,
11404 // including any padding space due to alignment is smaller than GROUP_SIZE
11405 // unless the only input section in group is bigger than GROUP_SIZE already.
11406 // Then an ARM stub table is created to follow the last input section
11407 // in group.  For each group an ARM stub table is created an is placed
11408 // after the last group.  If STUB_ALWAYS_AFTER_BRANCH is false, we further
11409 // extend the group after the stub table.
11410
11411 template<bool big_endian>
11412 void
11413 Target_arm<big_endian>::group_sections(
11414     Layout* layout,
11415     section_size_type group_size,
11416     bool stubs_always_after_branch,
11417     const Task* task)
11418 {
11419   // Group input sections and insert stub table
11420   Layout::Section_list section_list;
11421   layout->get_allocated_sections(&section_list);
11422   for (Layout::Section_list::const_iterator p = section_list.begin();
11423        p != section_list.end();
11424        ++p)
11425     {
11426       Arm_output_section<big_endian>* output_section =
11427         Arm_output_section<big_endian>::as_arm_output_section(*p);
11428       output_section->group_sections(group_size, stubs_always_after_branch,
11429                                      this, task);
11430     }
11431 }
11432
11433 // Relaxation hook.  This is where we do stub generation.
11434
11435 template<bool big_endian>
11436 bool
11437 Target_arm<big_endian>::do_relax(
11438     int pass,
11439     const Input_objects* input_objects,
11440     Symbol_table* symtab,
11441     Layout* layout,
11442     const Task* task)
11443 {
11444   // No need to generate stubs if this is a relocatable link.
11445   gold_assert(!parameters->options().relocatable());
11446
11447   // If this is the first pass, we need to group input sections into
11448   // stub groups.
11449   bool done_exidx_fixup = false;
11450   typedef typename Stub_table_list::iterator Stub_table_iterator;
11451   if (pass == 1)
11452     {
11453       // Determine the stub group size.  The group size is the absolute
11454       // value of the parameter --stub-group-size.  If --stub-group-size
11455       // is passed a negative value, we restrict stubs to be always after
11456       // the stubbed branches.
11457       int32_t stub_group_size_param =
11458         parameters->options().stub_group_size();
11459       bool stubs_always_after_branch = stub_group_size_param < 0;
11460       section_size_type stub_group_size = abs(stub_group_size_param);
11461
11462       if (stub_group_size == 1)
11463         {
11464           // Default value.
11465           // Thumb branch range is +-4MB has to be used as the default
11466           // maximum size (a given section can contain both ARM and Thumb
11467           // code, so the worst case has to be taken into account).  If we are
11468           // fixing cortex-a8 errata, the branch range has to be even smaller,
11469           // since wide conditional branch has a range of +-1MB only.
11470           //
11471           // This value is 48K less than that, which allows for 4096
11472           // 12-byte stubs.  If we exceed that, then we will fail to link.
11473           // The user will have to relink with an explicit group size
11474           // option.
11475             stub_group_size = 4145152;
11476         }
11477
11478       // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11479       // page as the first half of a 32-bit branch straddling two 4K pages.
11480       // This is a crude way of enforcing that.  In addition, long conditional
11481       // branches of THUMB-2 have a range of +-1M.  If we are fixing cortex-A8
11482       // erratum, limit the group size to  (1M - 12k) to avoid unreachable
11483       // cortex-A8 stubs from long conditional branches.
11484       if (this->fix_cortex_a8_)
11485         {
11486           stubs_always_after_branch = true;
11487           const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11488           stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11489         }
11490
11491       group_sections(layout, stub_group_size, stubs_always_after_branch, task);
11492
11493       // Also fix .ARM.exidx section coverage.
11494       Arm_output_section<big_endian>* exidx_output_section = NULL;
11495       for (Layout::Section_list::const_iterator p =
11496              layout->section_list().begin();
11497            p != layout->section_list().end();
11498            ++p)
11499         if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11500           {
11501             if (exidx_output_section == NULL)
11502               exidx_output_section =
11503                 Arm_output_section<big_endian>::as_arm_output_section(*p);
11504             else
11505               // We cannot handle this now.
11506               gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11507                            "non-relocatable link"),
11508                           exidx_output_section->name(),
11509                           (*p)->name());
11510           }
11511
11512       if (exidx_output_section != NULL)
11513         {
11514           this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11515                                    symtab, task);
11516           done_exidx_fixup = true;
11517         }
11518     }
11519   else
11520     {
11521       // If this is not the first pass, addresses and file offsets have
11522       // been reset at this point, set them here.
11523       for (Stub_table_iterator sp = this->stub_tables_.begin();
11524            sp != this->stub_tables_.end();
11525            ++sp)
11526         {
11527           Arm_input_section<big_endian>* owner = (*sp)->owner();
11528           off_t off = align_address(owner->original_size(),
11529                                     (*sp)->addralign());
11530           (*sp)->set_address_and_file_offset(owner->address() + off,
11531                                              owner->offset() + off);
11532         }
11533     }
11534
11535   // The Cortex-A8 stubs are sensitive to layout of code sections.  At the
11536   // beginning of each relaxation pass, just blow away all the stubs.
11537   // Alternatively, we could selectively remove only the stubs and reloc
11538   // information for code sections that have moved since the last pass.
11539   // That would require more book-keeping.
11540   if (this->fix_cortex_a8_)
11541     {
11542       // Clear all Cortex-A8 reloc information.
11543       for (typename Cortex_a8_relocs_info::const_iterator p =
11544              this->cortex_a8_relocs_info_.begin();
11545            p != this->cortex_a8_relocs_info_.end();
11546            ++p)
11547         delete p->second;
11548       this->cortex_a8_relocs_info_.clear();
11549
11550       // Remove all Cortex-A8 stubs.
11551       for (Stub_table_iterator sp = this->stub_tables_.begin();
11552            sp != this->stub_tables_.end();
11553            ++sp)
11554         (*sp)->remove_all_cortex_a8_stubs();
11555     }
11556
11557   // Scan relocs for relocation stubs
11558   for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11559        op != input_objects->relobj_end();
11560        ++op)
11561     {
11562       Arm_relobj<big_endian>* arm_relobj =
11563         Arm_relobj<big_endian>::as_arm_relobj(*op);
11564       // Lock the object so we can read from it.  This is only called
11565       // single-threaded from Layout::finalize, so it is OK to lock.
11566       Task_lock_obj<Object> tl(task, arm_relobj);
11567       arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11568     }
11569
11570   // Check all stub tables to see if any of them have their data sizes
11571   // or addresses alignments changed.  These are the only things that
11572   // matter.
11573   bool any_stub_table_changed = false;
11574   Unordered_set<const Output_section*> sections_needing_adjustment;
11575   for (Stub_table_iterator sp = this->stub_tables_.begin();
11576        (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11577        ++sp)
11578     {
11579       if ((*sp)->update_data_size_and_addralign())
11580         {
11581           // Update data size of stub table owner.
11582           Arm_input_section<big_endian>* owner = (*sp)->owner();
11583           uint64_t address = owner->address();
11584           off_t offset = owner->offset();
11585           owner->reset_address_and_file_offset();
11586           owner->set_address_and_file_offset(address, offset);
11587
11588           sections_needing_adjustment.insert(owner->output_section());
11589           any_stub_table_changed = true;
11590         }
11591     }
11592
11593   // Output_section_data::output_section() returns a const pointer but we
11594   // need to update output sections, so we record all output sections needing
11595   // update above and scan the sections here to find out what sections need
11596   // to be updated.
11597   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
11598       p != layout->section_list().end();
11599       ++p)
11600     {
11601       if (sections_needing_adjustment.find(*p)
11602           != sections_needing_adjustment.end())
11603         (*p)->set_section_offsets_need_adjustment();
11604     }
11605
11606   // Stop relaxation if no EXIDX fix-up and no stub table change.
11607   bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11608
11609   // Finalize the stubs in the last relaxation pass.
11610   if (!continue_relaxation)
11611     {
11612       for (Stub_table_iterator sp = this->stub_tables_.begin();
11613            (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11614             ++sp)
11615         (*sp)->finalize_stubs();
11616
11617       // Update output local symbol counts of objects if necessary.
11618       for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11619            op != input_objects->relobj_end();
11620            ++op)
11621         {
11622           Arm_relobj<big_endian>* arm_relobj =
11623             Arm_relobj<big_endian>::as_arm_relobj(*op);
11624
11625           // Update output local symbol counts.  We need to discard local
11626           // symbols defined in parts of input sections that are discarded by
11627           // relaxation.
11628           if (arm_relobj->output_local_symbol_count_needs_update())
11629             {
11630               // We need to lock the object's file to update it.
11631               Task_lock_obj<Object> tl(task, arm_relobj);
11632               arm_relobj->update_output_local_symbol_count();
11633             }
11634         }
11635     }
11636
11637   return continue_relaxation;
11638 }
11639
11640 // Relocate a stub.
11641
11642 template<bool big_endian>
11643 void
11644 Target_arm<big_endian>::relocate_stub(
11645     Stub* stub,
11646     const Relocate_info<32, big_endian>* relinfo,
11647     Output_section* output_section,
11648     unsigned char* view,
11649     Arm_address address,
11650     section_size_type view_size)
11651 {
11652   Relocate relocate;
11653   const Stub_template* stub_template = stub->stub_template();
11654   for (size_t i = 0; i < stub_template->reloc_count(); i++)
11655     {
11656       size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11657       const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11658
11659       unsigned int r_type = insn->r_type();
11660       section_size_type reloc_offset = stub_template->reloc_offset(i);
11661       section_size_type reloc_size = insn->size();
11662       gold_assert(reloc_offset + reloc_size <= view_size);
11663
11664       // This is the address of the stub destination.
11665       Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11666       Symbol_value<32> symval;
11667       symval.set_output_value(target);
11668
11669       // Synthesize a fake reloc just in case.  We don't have a symbol so
11670       // we use 0.
11671       unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11672       memset(reloc_buffer, 0, sizeof(reloc_buffer));
11673       elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11674       reloc_write.put_r_offset(reloc_offset);
11675       reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11676       elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11677
11678       relocate.relocate(relinfo, this, output_section,
11679                         this->fake_relnum_for_stubs, rel, r_type,
11680                         NULL, &symval, view + reloc_offset,
11681                         address + reloc_offset, reloc_size);
11682     }
11683 }
11684
11685 // Determine whether an object attribute tag takes an integer, a
11686 // string or both.
11687
11688 template<bool big_endian>
11689 int
11690 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11691 {
11692   if (tag == Object_attribute::Tag_compatibility)
11693     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11694             | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11695   else if (tag == elfcpp::Tag_nodefaults)
11696     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11697             | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11698   else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11699     return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11700   else if (tag < 32)
11701     return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11702   else
11703     return ((tag & 1) != 0
11704             ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11705             : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11706 }
11707
11708 // Reorder attributes.
11709 //
11710 // The ABI defines that Tag_conformance should be emitted first, and that
11711 // Tag_nodefaults should be second (if either is defined).  This sets those
11712 // two positions, and bumps up the position of all the remaining tags to
11713 // compensate.
11714
11715 template<bool big_endian>
11716 int
11717 Target_arm<big_endian>::do_attributes_order(int num) const
11718 {
11719   // Reorder the known object attributes in output.  We want to move
11720   // Tag_conformance to position 4 and Tag_conformance to position 5
11721   // and shift everything between 4 .. Tag_conformance - 1 to make room.
11722   if (num == 4)
11723     return elfcpp::Tag_conformance;
11724   if (num == 5)
11725     return elfcpp::Tag_nodefaults;
11726   if ((num - 2) < elfcpp::Tag_nodefaults)
11727     return num - 2;
11728   if ((num - 1) < elfcpp::Tag_conformance)
11729     return num - 1;
11730   return num;
11731 }
11732
11733 // Scan a span of THUMB code for Cortex-A8 erratum.
11734
11735 template<bool big_endian>
11736 void
11737 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11738     Arm_relobj<big_endian>* arm_relobj,
11739     unsigned int shndx,
11740     section_size_type span_start,
11741     section_size_type span_end,
11742     const unsigned char* view,
11743     Arm_address address)
11744 {
11745   // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11746   //
11747   // The opcode is BLX.W, BL.W, B.W, Bcc.W
11748   // The branch target is in the same 4KB region as the
11749   // first half of the branch.
11750   // The instruction before the branch is a 32-bit
11751   // length non-branch instruction.
11752   section_size_type i = span_start;
11753   bool last_was_32bit = false;
11754   bool last_was_branch = false;
11755   while (i < span_end)
11756     {
11757       typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11758       const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11759       uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11760       bool is_blx = false, is_b = false;
11761       bool is_bl = false, is_bcc = false;
11762
11763       bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11764       if (insn_32bit)
11765         {
11766           // Load the rest of the insn (in manual-friendly order).
11767           insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11768
11769           // Encoding T4: B<c>.W.
11770           is_b = (insn & 0xf800d000U) == 0xf0009000U;
11771           // Encoding T1: BL<c>.W.
11772           is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11773           // Encoding T2: BLX<c>.W.
11774           is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11775           // Encoding T3: B<c>.W (not permitted in IT block).
11776           is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11777                     && (insn & 0x07f00000U) != 0x03800000U);
11778         }
11779
11780       bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11781
11782       // If this instruction is a 32-bit THUMB branch that crosses a 4K
11783       // page boundary and it follows 32-bit non-branch instruction,
11784       // we need to work around.
11785       if (is_32bit_branch
11786           && ((address + i) & 0xfffU) == 0xffeU
11787           && last_was_32bit
11788           && !last_was_branch)
11789         {
11790           // Check to see if there is a relocation stub for this branch.
11791           bool force_target_arm = false;
11792           bool force_target_thumb = false;
11793           const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11794           Cortex_a8_relocs_info::const_iterator p =
11795             this->cortex_a8_relocs_info_.find(address + i);
11796
11797           if (p != this->cortex_a8_relocs_info_.end())
11798             {
11799               cortex_a8_reloc = p->second;
11800               bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11801
11802               if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11803                   && !target_is_thumb)
11804                 force_target_arm = true;
11805               else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11806                        && target_is_thumb)
11807                 force_target_thumb = true;
11808             }
11809
11810           off_t offset;
11811           Stub_type stub_type = arm_stub_none;
11812
11813           // Check if we have an offending branch instruction.
11814           uint16_t upper_insn = (insn >> 16) & 0xffffU;
11815           uint16_t lower_insn = insn & 0xffffU;
11816           typedef class Arm_relocate_functions<big_endian> RelocFuncs;
11817
11818           if (cortex_a8_reloc != NULL
11819               && cortex_a8_reloc->reloc_stub() != NULL)
11820             // We've already made a stub for this instruction, e.g.
11821             // it's a long branch or a Thumb->ARM stub.  Assume that
11822             // stub will suffice to work around the A8 erratum (see
11823             // setting of always_after_branch above).
11824             ;
11825           else if (is_bcc)
11826             {
11827               offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11828                                                               lower_insn);
11829               stub_type = arm_stub_a8_veneer_b_cond;
11830             }
11831           else if (is_b || is_bl || is_blx)
11832             {
11833               offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11834                                                          lower_insn);
11835               if (is_blx)
11836                 offset &= ~3;
11837
11838               stub_type = (is_blx
11839                            ? arm_stub_a8_veneer_blx
11840                            : (is_bl
11841                               ? arm_stub_a8_veneer_bl
11842                               : arm_stub_a8_veneer_b));
11843             }
11844
11845           if (stub_type != arm_stub_none)
11846             {
11847               Arm_address pc_for_insn = address + i + 4;
11848
11849               // The original instruction is a BL, but the target is
11850               // an ARM instruction.  If we were not making a stub,
11851               // the BL would have been converted to a BLX.  Use the
11852               // BLX stub instead in that case.
11853               if (this->may_use_v5t_interworking() && force_target_arm
11854                   && stub_type == arm_stub_a8_veneer_bl)
11855                 {
11856                   stub_type = arm_stub_a8_veneer_blx;
11857                   is_blx = true;
11858                   is_bl = false;
11859                 }
11860               // Conversely, if the original instruction was
11861               // BLX but the target is Thumb mode, use the BL stub.
11862               else if (force_target_thumb
11863                        && stub_type == arm_stub_a8_veneer_blx)
11864                 {
11865                   stub_type = arm_stub_a8_veneer_bl;
11866                   is_blx = false;
11867                   is_bl = true;
11868                 }
11869
11870               if (is_blx)
11871                 pc_for_insn &= ~3;
11872
11873               // If we found a relocation, use the proper destination,
11874               // not the offset in the (unrelocated) instruction.
11875               // Note this is always done if we switched the stub type above.
11876               if (cortex_a8_reloc != NULL)
11877                 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11878
11879               Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11880
11881               // Add a new stub if destination address in in the same page.
11882               if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11883                 {
11884                   Cortex_a8_stub* stub =
11885                     this->stub_factory_.make_cortex_a8_stub(stub_type,
11886                                                             arm_relobj, shndx,
11887                                                             address + i,
11888                                                             target, insn);
11889                   Stub_table<big_endian>* stub_table =
11890                     arm_relobj->stub_table(shndx);
11891                   gold_assert(stub_table != NULL);
11892                   stub_table->add_cortex_a8_stub(address + i, stub);
11893                 }
11894             }
11895         }
11896
11897       i += insn_32bit ? 4 : 2;
11898       last_was_32bit = insn_32bit;
11899       last_was_branch = is_32bit_branch;
11900     }
11901 }
11902
11903 // Apply the Cortex-A8 workaround.
11904
11905 template<bool big_endian>
11906 void
11907 Target_arm<big_endian>::apply_cortex_a8_workaround(
11908     const Cortex_a8_stub* stub,
11909     Arm_address stub_address,
11910     unsigned char* insn_view,
11911     Arm_address insn_address)
11912 {
11913   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11914   Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
11915   Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
11916   Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
11917   off_t branch_offset = stub_address - (insn_address + 4);
11918
11919   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
11920   switch (stub->stub_template()->type())
11921     {
11922     case arm_stub_a8_veneer_b_cond:
11923       // For a conditional branch, we re-write it to be an unconditional
11924       // branch to the stub.  We use the THUMB-2 encoding here.
11925       upper_insn = 0xf000U;
11926       lower_insn = 0xb800U;
11927       // Fall through
11928     case arm_stub_a8_veneer_b:
11929     case arm_stub_a8_veneer_bl:
11930     case arm_stub_a8_veneer_blx:
11931       if ((lower_insn & 0x5000U) == 0x4000U)
11932         // For a BLX instruction, make sure that the relocation is
11933         // rounded up to a word boundary.  This follows the semantics of
11934         // the instruction which specifies that bit 1 of the target
11935         // address will come from bit 1 of the base address.
11936         branch_offset = (branch_offset + 2) & ~3;
11937
11938       // Put BRANCH_OFFSET back into the insn.
11939       gold_assert(!Bits<25>::has_overflow32(branch_offset));
11940       upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
11941       lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
11942       break;
11943
11944     default:
11945       gold_unreachable();
11946     }
11947
11948   // Put the relocated value back in the object file:
11949   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
11950   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
11951 }
11952
11953 // Target selector for ARM.  Note this is never instantiated directly.
11954 // It's only used in Target_selector_arm_nacl, below.
11955
11956 template<bool big_endian>
11957 class Target_selector_arm : public Target_selector
11958 {
11959  public:
11960   Target_selector_arm()
11961     : Target_selector(elfcpp::EM_ARM, 32, big_endian,
11962                       (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
11963                       (big_endian ? "armelfb" : "armelf"))
11964   { }
11965
11966   Target*
11967   do_instantiate_target()
11968   { return new Target_arm<big_endian>(); }
11969 };
11970
11971 // Fix .ARM.exidx section coverage.
11972
11973 template<bool big_endian>
11974 void
11975 Target_arm<big_endian>::fix_exidx_coverage(
11976     Layout* layout,
11977     const Input_objects* input_objects,
11978     Arm_output_section<big_endian>* exidx_section,
11979     Symbol_table* symtab,
11980     const Task* task)
11981 {
11982   // We need to look at all the input sections in output in ascending
11983   // order of of output address.  We do that by building a sorted list
11984   // of output sections by addresses.  Then we looks at the output sections
11985   // in order.  The input sections in an output section are already sorted
11986   // by addresses within the output section.
11987
11988   typedef std::set<Output_section*, output_section_address_less_than>
11989       Sorted_output_section_list;
11990   Sorted_output_section_list sorted_output_sections;
11991
11992   // Find out all the output sections of input sections pointed by
11993   // EXIDX input sections.
11994   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
11995        p != input_objects->relobj_end();
11996        ++p)
11997     {
11998       Arm_relobj<big_endian>* arm_relobj =
11999         Arm_relobj<big_endian>::as_arm_relobj(*p);
12000       std::vector<unsigned int> shndx_list;
12001       arm_relobj->get_exidx_shndx_list(&shndx_list);
12002       for (size_t i = 0; i < shndx_list.size(); ++i)
12003         {
12004           const Arm_exidx_input_section* exidx_input_section =
12005             arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
12006           gold_assert(exidx_input_section != NULL);
12007           if (!exidx_input_section->has_errors())
12008             {
12009               unsigned int text_shndx = exidx_input_section->link();
12010               Output_section* os = arm_relobj->output_section(text_shndx);
12011               if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
12012                 sorted_output_sections.insert(os);
12013             }
12014         }
12015     }
12016
12017   // Go over the output sections in ascending order of output addresses.
12018   typedef typename Arm_output_section<big_endian>::Text_section_list
12019       Text_section_list;
12020   Text_section_list sorted_text_sections;
12021   for (typename Sorted_output_section_list::iterator p =
12022         sorted_output_sections.begin();
12023       p != sorted_output_sections.end();
12024       ++p)
12025     {
12026       Arm_output_section<big_endian>* arm_output_section =
12027         Arm_output_section<big_endian>::as_arm_output_section(*p);
12028       arm_output_section->append_text_sections_to_list(&sorted_text_sections);
12029     }
12030
12031   exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
12032                                     merge_exidx_entries(), task);
12033 }
12034
12035 template<bool big_endian>
12036 void
12037 Target_arm<big_endian>::do_define_standard_symbols(
12038     Symbol_table* symtab,
12039     Layout* layout)
12040 {
12041   // Handle the .ARM.exidx section.
12042   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
12043
12044   if (exidx_section != NULL)
12045     {
12046       // Create __exidx_start and __exidx_end symbols.
12047       symtab->define_in_output_data("__exidx_start",
12048                                     NULL, // version
12049                                     Symbol_table::PREDEFINED,
12050                                     exidx_section,
12051                                     0, // value
12052                                     0, // symsize
12053                                     elfcpp::STT_NOTYPE,
12054                                     elfcpp::STB_GLOBAL,
12055                                     elfcpp::STV_HIDDEN,
12056                                     0, // nonvis
12057                                     false, // offset_is_from_end
12058                                     true); // only_if_ref
12059
12060       symtab->define_in_output_data("__exidx_end",
12061                                     NULL, // version
12062                                     Symbol_table::PREDEFINED,
12063                                     exidx_section,
12064                                     0, // value
12065                                     0, // symsize
12066                                     elfcpp::STT_NOTYPE,
12067                                     elfcpp::STB_GLOBAL,
12068                                     elfcpp::STV_HIDDEN,
12069                                     0, // nonvis
12070                                     true, // offset_is_from_end
12071                                     true); // only_if_ref
12072     }
12073   else
12074     {
12075       // Define __exidx_start and __exidx_end even when .ARM.exidx
12076       // section is missing to match ld's behaviour.
12077       symtab->define_as_constant("__exidx_start", NULL,
12078                                  Symbol_table::PREDEFINED,
12079                                  0, 0, elfcpp::STT_OBJECT,
12080                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12081                                  true, false);
12082       symtab->define_as_constant("__exidx_end", NULL,
12083                                  Symbol_table::PREDEFINED,
12084                                  0, 0, elfcpp::STT_OBJECT,
12085                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12086                                  true, false);
12087     }
12088 }
12089
12090 // NaCl variant.  It uses different PLT contents.
12091
12092 template<bool big_endian>
12093 class Output_data_plt_arm_nacl;
12094
12095 template<bool big_endian>
12096 class Target_arm_nacl : public Target_arm<big_endian>
12097 {
12098  public:
12099   Target_arm_nacl()
12100     : Target_arm<big_endian>(&arm_nacl_info)
12101   { }
12102
12103  protected:
12104   virtual Output_data_plt_arm<big_endian>*
12105   do_make_data_plt(Layout* layout, Output_data_space* got_plt)
12106   { return new Output_data_plt_arm_nacl<big_endian>(layout, got_plt); }
12107
12108  private:
12109   static const Target::Target_info arm_nacl_info;
12110 };
12111
12112 template<bool big_endian>
12113 const Target::Target_info Target_arm_nacl<big_endian>::arm_nacl_info =
12114 {
12115   32,                   // size
12116   big_endian,           // is_big_endian
12117   elfcpp::EM_ARM,       // machine_code
12118   false,                // has_make_symbol
12119   false,                // has_resolve
12120   false,                // has_code_fill
12121   true,                 // is_default_stack_executable
12122   false,                // can_icf_inline_merge_sections
12123   '\0',                 // wrap_char
12124   "/lib/ld-nacl-arm.so.1", // dynamic_linker
12125   0x20000,              // default_text_segment_address
12126   0x10000,              // abi_pagesize (overridable by -z max-page-size)
12127   0x10000,              // common_pagesize (overridable by -z common-page-size)
12128   true,                 // isolate_execinstr
12129   0x10000000,           // rosegment_gap
12130   elfcpp::SHN_UNDEF,    // small_common_shndx
12131   elfcpp::SHN_UNDEF,    // large_common_shndx
12132   0,                    // small_common_section_flags
12133   0,                    // large_common_section_flags
12134   ".ARM.attributes",    // attributes_section
12135   "aeabi"               // attributes_vendor
12136 };
12137
12138 template<bool big_endian>
12139 class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
12140 {
12141  public:
12142   Output_data_plt_arm_nacl(Layout* layout, Output_data_space* got_plt)
12143     : Output_data_plt_arm<big_endian>(layout, 16, got_plt)
12144   { }
12145
12146  protected:
12147   // Return the offset of the first non-reserved PLT entry.
12148   virtual unsigned int
12149   do_first_plt_entry_offset() const
12150   { return sizeof(first_plt_entry); }
12151
12152   // Return the size of a PLT entry.
12153   virtual unsigned int
12154   do_get_plt_entry_size() const
12155   { return sizeof(plt_entry); }
12156
12157   virtual void
12158   do_fill_first_plt_entry(unsigned char* pov,
12159                           Arm_address got_address,
12160                           Arm_address plt_address);
12161
12162   virtual void
12163   do_fill_plt_entry(unsigned char* pov,
12164                     Arm_address got_address,
12165                     Arm_address plt_address,
12166                     unsigned int got_offset,
12167                     unsigned int plt_offset);
12168
12169  private:
12170   inline uint32_t arm_movw_immediate(uint32_t value)
12171   {
12172     return (value & 0x00000fff) | ((value & 0x0000f000) << 4);
12173   }
12174
12175   inline uint32_t arm_movt_immediate(uint32_t value)
12176   {
12177     return ((value & 0x0fff0000) >> 16) | ((value & 0xf0000000) >> 12);
12178   }
12179
12180   // Template for the first PLT entry.
12181   static const uint32_t first_plt_entry[16];
12182
12183   // Template for subsequent PLT entries.
12184   static const uint32_t plt_entry[4];
12185 };
12186
12187 // The first entry in the PLT.
12188 template<bool big_endian>
12189 const uint32_t Output_data_plt_arm_nacl<big_endian>::first_plt_entry[16] =
12190 {
12191   // First bundle:
12192   0xe300c000,                           // movw ip, #:lower16:&GOT[2]-.+8
12193   0xe340c000,                           // movt ip, #:upper16:&GOT[2]-.+8
12194   0xe08cc00f,                           // add  ip, ip, pc
12195   0xe52dc008,                           // str  ip, [sp, #-8]!
12196   // Second bundle:
12197   0xe7dfcf1f,                           // bfc  ip, #30, #2
12198   0xe59cc000,                           // ldr  ip, [ip]
12199   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
12200   0xe12fff1c,                           // bx   ip
12201   // Third bundle:
12202   0xe320f000,                           // nop
12203   0xe320f000,                           // nop
12204   0xe320f000,                           // nop
12205   // .Lplt_tail:
12206   0xe50dc004,                           // str  ip, [sp, #-4]
12207   // Fourth bundle:
12208   0xe7dfcf1f,                           // bfc  ip, #30, #2
12209   0xe59cc000,                           // ldr  ip, [ip]
12210   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
12211   0xe12fff1c,                           // bx   ip
12212 };
12213
12214 template<bool big_endian>
12215 void
12216 Output_data_plt_arm_nacl<big_endian>::do_fill_first_plt_entry(
12217     unsigned char* pov,
12218     Arm_address got_address,
12219     Arm_address plt_address)
12220 {
12221   // Write first PLT entry.  All but first two words are constants.
12222   const size_t num_first_plt_words = (sizeof(first_plt_entry)
12223                                       / sizeof(first_plt_entry[0]));
12224
12225   int32_t got_displacement = got_address + 8 - (plt_address + 16);
12226
12227   elfcpp::Swap<32, big_endian>::writeval
12228     (pov + 0, first_plt_entry[0] | arm_movw_immediate (got_displacement));
12229   elfcpp::Swap<32, big_endian>::writeval
12230     (pov + 4, first_plt_entry[1] | arm_movt_immediate (got_displacement));
12231
12232   for (size_t i = 2; i < num_first_plt_words; ++i)
12233     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
12234 }
12235
12236 // Subsequent entries in the PLT.
12237
12238 template<bool big_endian>
12239 const uint32_t Output_data_plt_arm_nacl<big_endian>::plt_entry[4] =
12240 {
12241   0xe300c000,                           // movw ip, #:lower16:&GOT[n]-.+8
12242   0xe340c000,                           // movt ip, #:upper16:&GOT[n]-.+8
12243   0xe08cc00f,                           // add  ip, ip, pc
12244   0xea000000,                           // b    .Lplt_tail
12245 };
12246
12247 template<bool big_endian>
12248 void
12249 Output_data_plt_arm_nacl<big_endian>::do_fill_plt_entry(
12250     unsigned char* pov,
12251     Arm_address got_address,
12252     Arm_address plt_address,
12253     unsigned int got_offset,
12254     unsigned int plt_offset)
12255 {
12256   // Calculate the displacement between the PLT slot and the
12257   // common tail that's part of the special initial PLT slot.
12258   int32_t tail_displacement = (plt_address + (11 * sizeof(uint32_t))
12259                                - (plt_address + plt_offset
12260                                   + sizeof(plt_entry) + sizeof(uint32_t)));
12261   gold_assert((tail_displacement & 3) == 0);
12262   tail_displacement >>= 2;
12263
12264   gold_assert ((tail_displacement & 0xff000000) == 0
12265                || (-tail_displacement & 0xff000000) == 0);
12266
12267   // Calculate the displacement between the PLT slot and the entry
12268   // in the GOT.  The offset accounts for the value produced by
12269   // adding to pc in the penultimate instruction of the PLT stub.
12270   const int32_t got_displacement = (got_address + got_offset
12271                                     - (plt_address + sizeof(plt_entry)));
12272
12273   elfcpp::Swap<32, big_endian>::writeval
12274     (pov + 0, plt_entry[0] | arm_movw_immediate (got_displacement));
12275   elfcpp::Swap<32, big_endian>::writeval
12276     (pov + 4, plt_entry[1] | arm_movt_immediate (got_displacement));
12277   elfcpp::Swap<32, big_endian>::writeval
12278     (pov + 8, plt_entry[2]);
12279   elfcpp::Swap<32, big_endian>::writeval
12280     (pov + 12, plt_entry[3] | (tail_displacement & 0x00ffffff));
12281 }
12282
12283 // Target selectors.
12284
12285 template<bool big_endian>
12286 class Target_selector_arm_nacl
12287   : public Target_selector_nacl<Target_selector_arm<big_endian>,
12288                                 Target_arm_nacl<big_endian> >
12289 {
12290  public:
12291   Target_selector_arm_nacl()
12292     : Target_selector_nacl<Target_selector_arm<big_endian>,
12293                            Target_arm_nacl<big_endian> >(
12294           "arm",
12295           big_endian ? "elf32-bigarm-nacl" : "elf32-littlearm-nacl",
12296           big_endian ? "armelfb_nacl" : "armelf_nacl")
12297   { }
12298 };
12299
12300 Target_selector_arm_nacl<false> target_selector_arm;
12301 Target_selector_arm_nacl<true> target_selector_armbe;
12302
12303 } // End anonymous namespace.