ld/
[external/binutils.git] / gold / arm.cc
1 // arm.cc -- arm target support for gold.
2
3 // Copyright 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
4 // Written by Doug Kwan <dougkwan@google.com> based on the i386 code
5 // by Ian Lance Taylor <iant@google.com>.
6 // This file also contains borrowed and adapted code from
7 // bfd/elf32-arm.c.
8
9 // This file is part of gold.
10
11 // This program is free software; you can redistribute it and/or modify
12 // it under the terms of the GNU General Public License as published by
13 // the Free Software Foundation; either version 3 of the License, or
14 // (at your option) any later version.
15
16 // This program is distributed in the hope that it will be useful,
17 // but WITHOUT ANY WARRANTY; without even the implied warranty of
18 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 // GNU General Public License for more details.
20
21 // You should have received a copy of the GNU General Public License
22 // along with this program; if not, write to the Free Software
23 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
24 // MA 02110-1301, USA.
25
26 #include "gold.h"
27
28 #include <cstring>
29 #include <limits>
30 #include <cstdio>
31 #include <string>
32 #include <algorithm>
33 #include <map>
34 #include <utility>
35 #include <set>
36
37 #include "elfcpp.h"
38 #include "parameters.h"
39 #include "reloc.h"
40 #include "arm.h"
41 #include "object.h"
42 #include "symtab.h"
43 #include "layout.h"
44 #include "output.h"
45 #include "copy-relocs.h"
46 #include "target.h"
47 #include "target-reloc.h"
48 #include "target-select.h"
49 #include "tls.h"
50 #include "defstd.h"
51 #include "gc.h"
52 #include "attributes.h"
53 #include "arm-reloc-property.h"
54 #include "nacl.h"
55
56 namespace
57 {
58
59 using namespace gold;
60
61 template<bool big_endian>
62 class Output_data_plt_arm;
63
64 template<bool big_endian>
65 class Output_data_plt_arm_standard;
66
67 template<bool big_endian>
68 class Stub_table;
69
70 template<bool big_endian>
71 class Arm_input_section;
72
73 class Arm_exidx_cantunwind;
74
75 class Arm_exidx_merged_section;
76
77 class Arm_exidx_fixup;
78
79 template<bool big_endian>
80 class Arm_output_section;
81
82 class Arm_exidx_input_section;
83
84 template<bool big_endian>
85 class Arm_relobj;
86
87 template<bool big_endian>
88 class Arm_relocate_functions;
89
90 template<bool big_endian>
91 class Arm_output_data_got;
92
93 template<bool big_endian>
94 class Target_arm;
95
96 // For convenience.
97 typedef elfcpp::Elf_types<32>::Elf_Addr Arm_address;
98
99 // Maximum branch offsets for ARM, THUMB and THUMB2.
100 const int32_t ARM_MAX_FWD_BRANCH_OFFSET = ((((1 << 23) - 1) << 2) + 8);
101 const int32_t ARM_MAX_BWD_BRANCH_OFFSET = ((-((1 << 23) << 2)) + 8);
102 const int32_t THM_MAX_FWD_BRANCH_OFFSET = ((1 << 22) -2 + 4);
103 const int32_t THM_MAX_BWD_BRANCH_OFFSET = (-(1 << 22) + 4);
104 const int32_t THM2_MAX_FWD_BRANCH_OFFSET = (((1 << 24) - 2) + 4);
105 const int32_t THM2_MAX_BWD_BRANCH_OFFSET = (-(1 << 24) + 4);
106
107 // Thread Control Block size.
108 const size_t ARM_TCB_SIZE = 8;
109
110 // The arm target class.
111 //
112 // This is a very simple port of gold for ARM-EABI.  It is intended for
113 // supporting Android only for the time being.
114 //
115 // TODOs:
116 // - Implement all static relocation types documented in arm-reloc.def.
117 // - Make PLTs more flexible for different architecture features like
118 //   Thumb-2 and BE8.
119 // There are probably a lot more.
120
121 // Ideally we would like to avoid using global variables but this is used
122 // very in many places and sometimes in loops.  If we use a function
123 // returning a static instance of Arm_reloc_property_table, it will be very
124 // slow in an threaded environment since the static instance needs to be
125 // locked.  The pointer is below initialized in the
126 // Target::do_select_as_default_target() hook so that we do not spend time
127 // building the table if we are not linking ARM objects.
128 //
129 // An alternative is to to process the information in arm-reloc.def in
130 // compilation time and generate a representation of it in PODs only.  That
131 // way we can avoid initialization when the linker starts.
132
133 Arm_reloc_property_table* arm_reloc_property_table = NULL;
134
135 // Instruction template class.  This class is similar to the insn_sequence
136 // struct in bfd/elf32-arm.c.
137
138 class Insn_template
139 {
140  public:
141   // Types of instruction templates.
142   enum Type
143     {
144       THUMB16_TYPE = 1,
145       // THUMB16_SPECIAL_TYPE is used by sub-classes of Stub for instruction
146       // templates with class-specific semantics.  Currently this is used
147       // only by the Cortex_a8_stub class for handling condition codes in
148       // conditional branches.
149       THUMB16_SPECIAL_TYPE,
150       THUMB32_TYPE,
151       ARM_TYPE,
152       DATA_TYPE
153     };
154
155   // Factory methods to create instruction templates in different formats.
156
157   static const Insn_template
158   thumb16_insn(uint32_t data)
159   { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 0); }
160
161   // A Thumb conditional branch, in which the proper condition is inserted
162   // when we build the stub.
163   static const Insn_template
164   thumb16_bcond_insn(uint32_t data)
165   { return Insn_template(data, THUMB16_SPECIAL_TYPE, elfcpp::R_ARM_NONE, 1); }
166
167   static const Insn_template
168   thumb32_insn(uint32_t data)
169   { return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_NONE, 0); }
170
171   static const Insn_template
172   thumb32_b_insn(uint32_t data, int reloc_addend)
173   {
174     return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_THM_JUMP24,
175                          reloc_addend);
176   }
177
178   static const Insn_template
179   arm_insn(uint32_t data)
180   { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_NONE, 0); }
181
182   static const Insn_template
183   arm_rel_insn(unsigned data, int reloc_addend)
184   { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_JUMP24, reloc_addend); }
185
186   static const Insn_template
187   data_word(unsigned data, unsigned int r_type, int reloc_addend)
188   { return Insn_template(data, DATA_TYPE, r_type, reloc_addend); }
189
190   // Accessors.  This class is used for read-only objects so no modifiers
191   // are provided.
192
193   uint32_t
194   data() const
195   { return this->data_; }
196
197   // Return the instruction sequence type of this.
198   Type
199   type() const
200   { return this->type_; }
201
202   // Return the ARM relocation type of this.
203   unsigned int
204   r_type() const
205   { return this->r_type_; }
206
207   int32_t
208   reloc_addend() const
209   { return this->reloc_addend_; }
210
211   // Return size of instruction template in bytes.
212   size_t
213   size() const;
214
215   // Return byte-alignment of instruction template.
216   unsigned
217   alignment() const;
218
219  private:
220   // We make the constructor private to ensure that only the factory
221   // methods are used.
222   inline
223   Insn_template(unsigned data, Type type, unsigned int r_type, int reloc_addend)
224     : data_(data), type_(type), r_type_(r_type), reloc_addend_(reloc_addend)
225   { }
226
227   // Instruction specific data.  This is used to store information like
228   // some of the instruction bits.
229   uint32_t data_;
230   // Instruction template type.
231   Type type_;
232   // Relocation type if there is a relocation or R_ARM_NONE otherwise.
233   unsigned int r_type_;
234   // Relocation addend.
235   int32_t reloc_addend_;
236 };
237
238 // Macro for generating code to stub types. One entry per long/short
239 // branch stub
240
241 #define DEF_STUBS \
242   DEF_STUB(long_branch_any_any) \
243   DEF_STUB(long_branch_v4t_arm_thumb) \
244   DEF_STUB(long_branch_thumb_only) \
245   DEF_STUB(long_branch_v4t_thumb_thumb) \
246   DEF_STUB(long_branch_v4t_thumb_arm) \
247   DEF_STUB(short_branch_v4t_thumb_arm) \
248   DEF_STUB(long_branch_any_arm_pic) \
249   DEF_STUB(long_branch_any_thumb_pic) \
250   DEF_STUB(long_branch_v4t_thumb_thumb_pic) \
251   DEF_STUB(long_branch_v4t_arm_thumb_pic) \
252   DEF_STUB(long_branch_v4t_thumb_arm_pic) \
253   DEF_STUB(long_branch_thumb_only_pic) \
254   DEF_STUB(a8_veneer_b_cond) \
255   DEF_STUB(a8_veneer_b) \
256   DEF_STUB(a8_veneer_bl) \
257   DEF_STUB(a8_veneer_blx) \
258   DEF_STUB(v4_veneer_bx)
259
260 // Stub types.
261
262 #define DEF_STUB(x) arm_stub_##x,
263 typedef enum
264   {
265     arm_stub_none,
266     DEF_STUBS
267
268     // First reloc stub type.
269     arm_stub_reloc_first = arm_stub_long_branch_any_any,
270     // Last  reloc stub type.
271     arm_stub_reloc_last = arm_stub_long_branch_thumb_only_pic,
272
273     // First Cortex-A8 stub type.
274     arm_stub_cortex_a8_first = arm_stub_a8_veneer_b_cond,
275     // Last Cortex-A8 stub type.
276     arm_stub_cortex_a8_last = arm_stub_a8_veneer_blx,
277
278     // Last stub type.
279     arm_stub_type_last = arm_stub_v4_veneer_bx
280   } Stub_type;
281 #undef DEF_STUB
282
283 // Stub template class.  Templates are meant to be read-only objects.
284 // A stub template for a stub type contains all read-only attributes
285 // common to all stubs of the same type.
286
287 class Stub_template
288 {
289  public:
290   Stub_template(Stub_type, const Insn_template*, size_t);
291
292   ~Stub_template()
293   { }
294
295   // Return stub type.
296   Stub_type
297   type() const
298   { return this->type_; }
299
300   // Return an array of instruction templates.
301   const Insn_template*
302   insns() const
303   { return this->insns_; }
304
305   // Return size of template in number of instructions.
306   size_t
307   insn_count() const
308   { return this->insn_count_; }
309
310   // Return size of template in bytes.
311   size_t
312   size() const
313   { return this->size_; }
314
315   // Return alignment of the stub template.
316   unsigned
317   alignment() const
318   { return this->alignment_; }
319
320   // Return whether entry point is in thumb mode.
321   bool
322   entry_in_thumb_mode() const
323   { return this->entry_in_thumb_mode_; }
324
325   // Return number of relocations in this template.
326   size_t
327   reloc_count() const
328   { return this->relocs_.size(); }
329
330   // Return index of the I-th instruction with relocation.
331   size_t
332   reloc_insn_index(size_t i) const
333   {
334     gold_assert(i < this->relocs_.size());
335     return this->relocs_[i].first;
336   }
337
338   // Return the offset of the I-th instruction with relocation from the
339   // beginning of the stub.
340   section_size_type
341   reloc_offset(size_t i) const
342   {
343     gold_assert(i < this->relocs_.size());
344     return this->relocs_[i].second;
345   }
346
347  private:
348   // This contains information about an instruction template with a relocation
349   // and its offset from start of stub.
350   typedef std::pair<size_t, section_size_type> Reloc;
351
352   // A Stub_template may not be copied.  We want to share templates as much
353   // as possible.
354   Stub_template(const Stub_template&);
355   Stub_template& operator=(const Stub_template&);
356
357   // Stub type.
358   Stub_type type_;
359   // Points to an array of Insn_templates.
360   const Insn_template* insns_;
361   // Number of Insn_templates in insns_[].
362   size_t insn_count_;
363   // Size of templated instructions in bytes.
364   size_t size_;
365   // Alignment of templated instructions.
366   unsigned alignment_;
367   // Flag to indicate if entry is in thumb mode.
368   bool entry_in_thumb_mode_;
369   // A table of reloc instruction indices and offsets.  We can find these by
370   // looking at the instruction templates but we pre-compute and then stash
371   // them here for speed.
372   std::vector<Reloc> relocs_;
373 };
374
375 //
376 // A class for code stubs.  This is a base class for different type of
377 // stubs used in the ARM target.
378 //
379
380 class Stub
381 {
382  private:
383   static const section_offset_type invalid_offset =
384     static_cast<section_offset_type>(-1);
385
386  public:
387   Stub(const Stub_template* stub_template)
388     : stub_template_(stub_template), offset_(invalid_offset)
389   { }
390
391   virtual
392    ~Stub()
393   { }
394
395   // Return the stub template.
396   const Stub_template*
397   stub_template() const
398   { return this->stub_template_; }
399
400   // Return offset of code stub from beginning of its containing stub table.
401   section_offset_type
402   offset() const
403   {
404     gold_assert(this->offset_ != invalid_offset);
405     return this->offset_;
406   }
407
408   // Set offset of code stub from beginning of its containing stub table.
409   void
410   set_offset(section_offset_type offset)
411   { this->offset_ = offset; }
412
413   // Return the relocation target address of the i-th relocation in the
414   // stub.  This must be defined in a child class.
415   Arm_address
416   reloc_target(size_t i)
417   { return this->do_reloc_target(i); }
418
419   // Write a stub at output VIEW.  BIG_ENDIAN select how a stub is written.
420   void
421   write(unsigned char* view, section_size_type view_size, bool big_endian)
422   { this->do_write(view, view_size, big_endian); }
423
424   // Return the instruction for THUMB16_SPECIAL_TYPE instruction template
425   // for the i-th instruction.
426   uint16_t
427   thumb16_special(size_t i)
428   { return this->do_thumb16_special(i); }
429
430  protected:
431   // This must be defined in the child class.
432   virtual Arm_address
433   do_reloc_target(size_t) = 0;
434
435   // This may be overridden in the child class.
436   virtual void
437   do_write(unsigned char* view, section_size_type view_size, bool big_endian)
438   {
439     if (big_endian)
440       this->do_fixed_endian_write<true>(view, view_size);
441     else
442       this->do_fixed_endian_write<false>(view, view_size);
443   }
444
445   // This must be overridden if a child class uses the THUMB16_SPECIAL_TYPE
446   // instruction template.
447   virtual uint16_t
448   do_thumb16_special(size_t)
449   { gold_unreachable(); }
450
451  private:
452   // A template to implement do_write.
453   template<bool big_endian>
454   void inline
455   do_fixed_endian_write(unsigned char*, section_size_type);
456
457   // Its template.
458   const Stub_template* stub_template_;
459   // Offset within the section of containing this stub.
460   section_offset_type offset_;
461 };
462
463 // Reloc stub class.  These are stubs we use to fix up relocation because
464 // of limited branch ranges.
465
466 class Reloc_stub : public Stub
467 {
468  public:
469   static const unsigned int invalid_index = static_cast<unsigned int>(-1);
470   // We assume we never jump to this address.
471   static const Arm_address invalid_address = static_cast<Arm_address>(-1);
472
473   // Return destination address.
474   Arm_address
475   destination_address() const
476   {
477     gold_assert(this->destination_address_ != this->invalid_address);
478     return this->destination_address_;
479   }
480
481   // Set destination address.
482   void
483   set_destination_address(Arm_address address)
484   {
485     gold_assert(address != this->invalid_address);
486     this->destination_address_ = address;
487   }
488
489   // Reset destination address.
490   void
491   reset_destination_address()
492   { this->destination_address_ = this->invalid_address; }
493
494   // Determine stub type for a branch of a relocation of R_TYPE going
495   // from BRANCH_ADDRESS to BRANCH_TARGET.  If TARGET_IS_THUMB is set,
496   // the branch target is a thumb instruction.  TARGET is used for look
497   // up ARM-specific linker settings.
498   static Stub_type
499   stub_type_for_reloc(unsigned int r_type, Arm_address branch_address,
500                       Arm_address branch_target, bool target_is_thumb);
501
502   // Reloc_stub key.  A key is logically a triplet of a stub type, a symbol
503   // and an addend.  Since we treat global and local symbol differently, we
504   // use a Symbol object for a global symbol and a object-index pair for
505   // a local symbol.
506   class Key
507   {
508    public:
509     // If SYMBOL is not null, this is a global symbol, we ignore RELOBJ and
510     // R_SYM.  Otherwise, this is a local symbol and RELOBJ must non-NULL
511     // and R_SYM must not be invalid_index.
512     Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj,
513         unsigned int r_sym, int32_t addend)
514       : stub_type_(stub_type), addend_(addend)
515     {
516       if (symbol != NULL)
517         {
518           this->r_sym_ = Reloc_stub::invalid_index;
519           this->u_.symbol = symbol;
520         }
521       else
522         {
523           gold_assert(relobj != NULL && r_sym != invalid_index);
524           this->r_sym_ = r_sym;
525           this->u_.relobj = relobj;
526         }
527     }
528
529     ~Key()
530     { }
531
532     // Accessors: Keys are meant to be read-only object so no modifiers are
533     // provided.
534
535     // Return stub type.
536     Stub_type
537     stub_type() const
538     { return this->stub_type_; }
539
540     // Return the local symbol index or invalid_index.
541     unsigned int
542     r_sym() const
543     { return this->r_sym_; }
544
545     // Return the symbol if there is one.
546     const Symbol*
547     symbol() const
548     { return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; }
549
550     // Return the relobj if there is one.
551     const Relobj*
552     relobj() const
553     { return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; }
554
555     // Whether this equals to another key k.
556     bool
557     eq(const Key& k) const
558     {
559       return ((this->stub_type_ == k.stub_type_)
560               && (this->r_sym_ == k.r_sym_)
561               && ((this->r_sym_ != Reloc_stub::invalid_index)
562                   ? (this->u_.relobj == k.u_.relobj)
563                   : (this->u_.symbol == k.u_.symbol))
564               && (this->addend_ == k.addend_));
565     }
566
567     // Return a hash value.
568     size_t
569     hash_value() const
570     {
571       return (this->stub_type_
572               ^ this->r_sym_
573               ^ gold::string_hash<char>(
574                     (this->r_sym_ != Reloc_stub::invalid_index)
575                     ? this->u_.relobj->name().c_str()
576                     : this->u_.symbol->name())
577               ^ this->addend_);
578     }
579
580     // Functors for STL associative containers.
581     struct hash
582     {
583       size_t
584       operator()(const Key& k) const
585       { return k.hash_value(); }
586     };
587
588     struct equal_to
589     {
590       bool
591       operator()(const Key& k1, const Key& k2) const
592       { return k1.eq(k2); }
593     };
594
595     // Name of key.  This is mainly for debugging.
596     std::string
597     name() const;
598
599    private:
600     // Stub type.
601     Stub_type stub_type_;
602     // If this is a local symbol, this is the index in the defining object.
603     // Otherwise, it is invalid_index for a global symbol.
604     unsigned int r_sym_;
605     // If r_sym_ is an invalid index, this points to a global symbol.
606     // Otherwise, it points to a relobj.  We used the unsized and target
607     // independent Symbol and Relobj classes instead of Sized_symbol<32> and
608     // Arm_relobj, in order to avoid making the stub class a template
609     // as most of the stub machinery is endianness-neutral.  However, it
610     // may require a bit of casting done by users of this class.
611     union
612     {
613       const Symbol* symbol;
614       const Relobj* relobj;
615     } u_;
616     // Addend associated with a reloc.
617     int32_t addend_;
618   };
619
620  protected:
621   // Reloc_stubs are created via a stub factory.  So these are protected.
622   Reloc_stub(const Stub_template* stub_template)
623     : Stub(stub_template), destination_address_(invalid_address)
624   { }
625
626   ~Reloc_stub()
627   { }
628
629   friend class Stub_factory;
630
631   // Return the relocation target address of the i-th relocation in the
632   // stub.
633   Arm_address
634   do_reloc_target(size_t i)
635   {
636     // All reloc stub have only one relocation.
637     gold_assert(i == 0);
638     return this->destination_address_;
639   }
640
641  private:
642   // Address of destination.
643   Arm_address destination_address_;
644 };
645
646 // Cortex-A8 stub class.  We need a Cortex-A8 stub to redirect any 32-bit
647 // THUMB branch that meets the following conditions:
648 //
649 // 1. The branch straddles across a page boundary. i.e. lower 12-bit of
650 //    branch address is 0xffe.
651 // 2. The branch target address is in the same page as the first word of the
652 //    branch.
653 // 3. The branch follows a 32-bit instruction which is not a branch.
654 //
655 // To do the fix up, we need to store the address of the branch instruction
656 // and its target at least.  We also need to store the original branch
657 // instruction bits for the condition code in a conditional branch.  The
658 // condition code is used in a special instruction template.  We also want
659 // to identify input sections needing Cortex-A8 workaround quickly.  We store
660 // extra information about object and section index of the code section
661 // containing a branch being fixed up.  The information is used to mark
662 // the code section when we finalize the Cortex-A8 stubs.
663 //
664
665 class Cortex_a8_stub : public Stub
666 {
667  public:
668   ~Cortex_a8_stub()
669   { }
670
671   // Return the object of the code section containing the branch being fixed
672   // up.
673   Relobj*
674   relobj() const
675   { return this->relobj_; }
676
677   // Return the section index of the code section containing the branch being
678   // fixed up.
679   unsigned int
680   shndx() const
681   { return this->shndx_; }
682
683   // Return the source address of stub.  This is the address of the original
684   // branch instruction.  LSB is 1 always set to indicate that it is a THUMB
685   // instruction.
686   Arm_address
687   source_address() const
688   { return this->source_address_; }
689
690   // Return the destination address of the stub.  This is the branch taken
691   // address of the original branch instruction.  LSB is 1 if it is a THUMB
692   // instruction address.
693   Arm_address
694   destination_address() const
695   { return this->destination_address_; }
696
697   // Return the instruction being fixed up.
698   uint32_t
699   original_insn() const
700   { return this->original_insn_; }
701
702  protected:
703   // Cortex_a8_stubs are created via a stub factory.  So these are protected.
704   Cortex_a8_stub(const Stub_template* stub_template, Relobj* relobj,
705                  unsigned int shndx, Arm_address source_address,
706                  Arm_address destination_address, uint32_t original_insn)
707     : Stub(stub_template), relobj_(relobj), shndx_(shndx),
708       source_address_(source_address | 1U),
709       destination_address_(destination_address),
710       original_insn_(original_insn)
711   { }
712
713   friend class Stub_factory;
714
715   // Return the relocation target address of the i-th relocation in the
716   // stub.
717   Arm_address
718   do_reloc_target(size_t i)
719   {
720     if (this->stub_template()->type() == arm_stub_a8_veneer_b_cond)
721       {
722         // The conditional branch veneer has two relocations.
723         gold_assert(i < 2);
724         return i == 0 ? this->source_address_ + 4 : this->destination_address_;
725       }
726     else
727       {
728         // All other Cortex-A8 stubs have only one relocation.
729         gold_assert(i == 0);
730         return this->destination_address_;
731       }
732   }
733
734   // Return an instruction for the THUMB16_SPECIAL_TYPE instruction template.
735   uint16_t
736   do_thumb16_special(size_t);
737
738  private:
739   // Object of the code section containing the branch being fixed up.
740   Relobj* relobj_;
741   // Section index of the code section containing the branch begin fixed up.
742   unsigned int shndx_;
743   // Source address of original branch.
744   Arm_address source_address_;
745   // Destination address of the original branch.
746   Arm_address destination_address_;
747   // Original branch instruction.  This is needed for copying the condition
748   // code from a condition branch to its stub.
749   uint32_t original_insn_;
750 };
751
752 // ARMv4 BX Rx branch relocation stub class.
753 class Arm_v4bx_stub : public Stub
754 {
755  public:
756   ~Arm_v4bx_stub()
757   { }
758
759   // Return the associated register.
760   uint32_t
761   reg() const
762   { return this->reg_; }
763
764  protected:
765   // Arm V4BX stubs are created via a stub factory.  So these are protected.
766   Arm_v4bx_stub(const Stub_template* stub_template, const uint32_t reg)
767     : Stub(stub_template), reg_(reg)
768   { }
769
770   friend class Stub_factory;
771
772   // Return the relocation target address of the i-th relocation in the
773   // stub.
774   Arm_address
775   do_reloc_target(size_t)
776   { gold_unreachable(); }
777
778   // This may be overridden in the child class.
779   virtual void
780   do_write(unsigned char* view, section_size_type view_size, bool big_endian)
781   {
782     if (big_endian)
783       this->do_fixed_endian_v4bx_write<true>(view, view_size);
784     else
785       this->do_fixed_endian_v4bx_write<false>(view, view_size);
786   }
787
788  private:
789   // A template to implement do_write.
790   template<bool big_endian>
791   void inline
792   do_fixed_endian_v4bx_write(unsigned char* view, section_size_type)
793   {
794     const Insn_template* insns = this->stub_template()->insns();
795     elfcpp::Swap<32, big_endian>::writeval(view,
796                                            (insns[0].data()
797                                            + (this->reg_ << 16)));
798     view += insns[0].size();
799     elfcpp::Swap<32, big_endian>::writeval(view,
800                                            (insns[1].data() + this->reg_));
801     view += insns[1].size();
802     elfcpp::Swap<32, big_endian>::writeval(view,
803                                            (insns[2].data() + this->reg_));
804   }
805
806   // A register index (r0-r14), which is associated with the stub.
807   uint32_t reg_;
808 };
809
810 // Stub factory class.
811
812 class Stub_factory
813 {
814  public:
815   // Return the unique instance of this class.
816   static const Stub_factory&
817   get_instance()
818   {
819     static Stub_factory singleton;
820     return singleton;
821   }
822
823   // Make a relocation stub.
824   Reloc_stub*
825   make_reloc_stub(Stub_type stub_type) const
826   {
827     gold_assert(stub_type >= arm_stub_reloc_first
828                 && stub_type <= arm_stub_reloc_last);
829     return new Reloc_stub(this->stub_templates_[stub_type]);
830   }
831
832   // Make a Cortex-A8 stub.
833   Cortex_a8_stub*
834   make_cortex_a8_stub(Stub_type stub_type, Relobj* relobj, unsigned int shndx,
835                       Arm_address source, Arm_address destination,
836                       uint32_t original_insn) const
837   {
838     gold_assert(stub_type >= arm_stub_cortex_a8_first
839                 && stub_type <= arm_stub_cortex_a8_last);
840     return new Cortex_a8_stub(this->stub_templates_[stub_type], relobj, shndx,
841                               source, destination, original_insn);
842   }
843
844   // Make an ARM V4BX relocation stub.
845   // This method creates a stub from the arm_stub_v4_veneer_bx template only.
846   Arm_v4bx_stub*
847   make_arm_v4bx_stub(uint32_t reg) const
848   {
849     gold_assert(reg < 0xf);
850     return new Arm_v4bx_stub(this->stub_templates_[arm_stub_v4_veneer_bx],
851                              reg);
852   }
853
854  private:
855   // Constructor and destructor are protected since we only return a single
856   // instance created in Stub_factory::get_instance().
857
858   Stub_factory();
859
860   // A Stub_factory may not be copied since it is a singleton.
861   Stub_factory(const Stub_factory&);
862   Stub_factory& operator=(Stub_factory&);
863
864   // Stub templates.  These are initialized in the constructor.
865   const Stub_template* stub_templates_[arm_stub_type_last+1];
866 };
867
868 // A class to hold stubs for the ARM target.
869
870 template<bool big_endian>
871 class Stub_table : public Output_data
872 {
873  public:
874   Stub_table(Arm_input_section<big_endian>* owner)
875     : Output_data(), owner_(owner), reloc_stubs_(), reloc_stubs_size_(0),
876       reloc_stubs_addralign_(1), cortex_a8_stubs_(), arm_v4bx_stubs_(0xf),
877       prev_data_size_(0), prev_addralign_(1)
878   { }
879
880   ~Stub_table()
881   { }
882
883   // Owner of this stub table.
884   Arm_input_section<big_endian>*
885   owner() const
886   { return this->owner_; }
887
888   // Whether this stub table is empty.
889   bool
890   empty() const
891   {
892     return (this->reloc_stubs_.empty()
893             && this->cortex_a8_stubs_.empty()
894             && this->arm_v4bx_stubs_.empty());
895   }
896
897   // Return the current data size.
898   off_t
899   current_data_size() const
900   { return this->current_data_size_for_child(); }
901
902   // Add a STUB using KEY.  The caller is responsible for avoiding addition
903   // if a STUB with the same key has already been added.
904   void
905   add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key)
906   {
907     const Stub_template* stub_template = stub->stub_template();
908     gold_assert(stub_template->type() == key.stub_type());
909     this->reloc_stubs_[key] = stub;
910
911     // Assign stub offset early.  We can do this because we never remove
912     // reloc stubs and they are in the beginning of the stub table.
913     uint64_t align = stub_template->alignment();
914     this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_, align);
915     stub->set_offset(this->reloc_stubs_size_);
916     this->reloc_stubs_size_ += stub_template->size();
917     this->reloc_stubs_addralign_ =
918       std::max(this->reloc_stubs_addralign_, align);
919   }
920
921   // Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS.
922   // The caller is responsible for avoiding addition if a STUB with the same
923   // address has already been added.
924   void
925   add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub)
926   {
927     std::pair<Arm_address, Cortex_a8_stub*> value(address, stub);
928     this->cortex_a8_stubs_.insert(value);
929   }
930
931   // Add an ARM V4BX relocation stub. A register index will be retrieved
932   // from the stub.
933   void
934   add_arm_v4bx_stub(Arm_v4bx_stub* stub)
935   {
936     gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL);
937     this->arm_v4bx_stubs_[stub->reg()] = stub;
938   }
939
940   // Remove all Cortex-A8 stubs.
941   void
942   remove_all_cortex_a8_stubs();
943
944   // Look up a relocation stub using KEY.  Return NULL if there is none.
945   Reloc_stub*
946   find_reloc_stub(const Reloc_stub::Key& key) const
947   {
948     typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
949     return (p != this->reloc_stubs_.end()) ? p->second : NULL;
950   }
951
952   // Look up an arm v4bx relocation stub using the register index.
953   // Return NULL if there is none.
954   Arm_v4bx_stub*
955   find_arm_v4bx_stub(const uint32_t reg) const
956   {
957     gold_assert(reg < 0xf);
958     return this->arm_v4bx_stubs_[reg];
959   }
960
961   // Relocate stubs in this stub table.
962   void
963   relocate_stubs(const Relocate_info<32, big_endian>*,
964                  Target_arm<big_endian>*, Output_section*,
965                  unsigned char*, Arm_address, section_size_type);
966
967   // Update data size and alignment at the end of a relaxation pass.  Return
968   // true if either data size or alignment is different from that of the
969   // previous relaxation pass.
970   bool
971   update_data_size_and_addralign();
972
973   // Finalize stubs.  Set the offsets of all stubs and mark input sections
974   // needing the Cortex-A8 workaround.
975   void
976   finalize_stubs();
977
978   // Apply Cortex-A8 workaround to an address range.
979   void
980   apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*,
981                                               unsigned char*, Arm_address,
982                                               section_size_type);
983
984  protected:
985   // Write out section contents.
986   void
987   do_write(Output_file*);
988
989   // Return the required alignment.
990   uint64_t
991   do_addralign() const
992   { return this->prev_addralign_; }
993
994   // Reset address and file offset.
995   void
996   do_reset_address_and_file_offset()
997   { this->set_current_data_size_for_child(this->prev_data_size_); }
998
999   // Set final data size.
1000   void
1001   set_final_data_size()
1002   { this->set_data_size(this->current_data_size()); }
1003
1004  private:
1005   // Relocate one stub.
1006   void
1007   relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
1008                 Target_arm<big_endian>*, Output_section*,
1009                 unsigned char*, Arm_address, section_size_type);
1010
1011   // Unordered map of relocation stubs.
1012   typedef
1013     Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
1014                   Reloc_stub::Key::equal_to>
1015     Reloc_stub_map;
1016
1017   // List of Cortex-A8 stubs ordered by addresses of branches being
1018   // fixed up in output.
1019   typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list;
1020   // List of Arm V4BX relocation stubs ordered by associated registers.
1021   typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list;
1022
1023   // Owner of this stub table.
1024   Arm_input_section<big_endian>* owner_;
1025   // The relocation stubs.
1026   Reloc_stub_map reloc_stubs_;
1027   // Size of reloc stubs.
1028   off_t reloc_stubs_size_;
1029   // Maximum address alignment of reloc stubs.
1030   uint64_t reloc_stubs_addralign_;
1031   // The cortex_a8_stubs.
1032   Cortex_a8_stub_list cortex_a8_stubs_;
1033   // The Arm V4BX relocation stubs.
1034   Arm_v4bx_stub_list arm_v4bx_stubs_;
1035   // data size of this in the previous pass.
1036   off_t prev_data_size_;
1037   // address alignment of this in the previous pass.
1038   uint64_t prev_addralign_;
1039 };
1040
1041 // Arm_exidx_cantunwind class.  This represents an EXIDX_CANTUNWIND entry
1042 // we add to the end of an EXIDX input section that goes into the output.
1043
1044 class Arm_exidx_cantunwind : public Output_section_data
1045 {
1046  public:
1047   Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
1048     : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
1049   { }
1050
1051   // Return the object containing the section pointed by this.
1052   Relobj*
1053   relobj() const
1054   { return this->relobj_; }
1055
1056   // Return the section index of the section pointed by this.
1057   unsigned int
1058   shndx() const
1059   { return this->shndx_; }
1060
1061  protected:
1062   void
1063   do_write(Output_file* of)
1064   {
1065     if (parameters->target().is_big_endian())
1066       this->do_fixed_endian_write<true>(of);
1067     else
1068       this->do_fixed_endian_write<false>(of);
1069   }
1070
1071   // Write to a map file.
1072   void
1073   do_print_to_mapfile(Mapfile* mapfile) const
1074   { mapfile->print_output_data(this, _("** ARM cantunwind")); }
1075
1076  private:
1077   // Implement do_write for a given endianness.
1078   template<bool big_endian>
1079   void inline
1080   do_fixed_endian_write(Output_file*);
1081
1082   // The object containing the section pointed by this.
1083   Relobj* relobj_;
1084   // The section index of the section pointed by this.
1085   unsigned int shndx_;
1086 };
1087
1088 // During EXIDX coverage fix-up, we compact an EXIDX section.  The
1089 // Offset map is used to map input section offset within the EXIDX section
1090 // to the output offset from the start of this EXIDX section.
1091
1092 typedef std::map<section_offset_type, section_offset_type>
1093         Arm_exidx_section_offset_map;
1094
1095 // Arm_exidx_merged_section class.  This represents an EXIDX input section
1096 // with some of its entries merged.
1097
1098 class Arm_exidx_merged_section : public Output_relaxed_input_section
1099 {
1100  public:
1101   // Constructor for Arm_exidx_merged_section.
1102   // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
1103   // SECTION_OFFSET_MAP points to a section offset map describing how
1104   // parts of the input section are mapped to output.  DELETED_BYTES is
1105   // the number of bytes deleted from the EXIDX input section.
1106   Arm_exidx_merged_section(
1107       const Arm_exidx_input_section& exidx_input_section,
1108       const Arm_exidx_section_offset_map& section_offset_map,
1109       uint32_t deleted_bytes);
1110
1111   // Build output contents.
1112   void
1113   build_contents(const unsigned char*, section_size_type);
1114
1115   // Return the original EXIDX input section.
1116   const Arm_exidx_input_section&
1117   exidx_input_section() const
1118   { return this->exidx_input_section_; }
1119
1120   // Return the section offset map.
1121   const Arm_exidx_section_offset_map&
1122   section_offset_map() const
1123   { return this->section_offset_map_; }
1124
1125  protected:
1126   // Write merged section into file OF.
1127   void
1128   do_write(Output_file* of);
1129
1130   bool
1131   do_output_offset(const Relobj*, unsigned int, section_offset_type,
1132                   section_offset_type*) const;
1133
1134  private:
1135   // Original EXIDX input section.
1136   const Arm_exidx_input_section& exidx_input_section_;
1137   // Section offset map.
1138   const Arm_exidx_section_offset_map& section_offset_map_;
1139   // Merged section contents.  We need to keep build the merged section
1140   // and save it here to avoid accessing the original EXIDX section when
1141   // we cannot lock the sections' object.
1142   unsigned char* section_contents_;
1143 };
1144
1145 // A class to wrap an ordinary input section containing executable code.
1146
1147 template<bool big_endian>
1148 class Arm_input_section : public Output_relaxed_input_section
1149 {
1150  public:
1151   Arm_input_section(Relobj* relobj, unsigned int shndx)
1152     : Output_relaxed_input_section(relobj, shndx, 1),
1153       original_addralign_(1), original_size_(0), stub_table_(NULL),
1154       original_contents_(NULL)
1155   { }
1156
1157   ~Arm_input_section()
1158   { delete[] this->original_contents_; }
1159
1160   // Initialize.
1161   void
1162   init();
1163
1164   // Whether this is a stub table owner.
1165   bool
1166   is_stub_table_owner() const
1167   { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
1168
1169   // Return the stub table.
1170   Stub_table<big_endian>*
1171   stub_table() const
1172   { return this->stub_table_; }
1173
1174   // Set the stub_table.
1175   void
1176   set_stub_table(Stub_table<big_endian>* stub_table)
1177   { this->stub_table_ = stub_table; }
1178
1179   // Downcast a base pointer to an Arm_input_section pointer.  This is
1180   // not type-safe but we only use Arm_input_section not the base class.
1181   static Arm_input_section<big_endian>*
1182   as_arm_input_section(Output_relaxed_input_section* poris)
1183   { return static_cast<Arm_input_section<big_endian>*>(poris); }
1184
1185   // Return the original size of the section.
1186   uint32_t
1187   original_size() const
1188   { return this->original_size_; }
1189
1190  protected:
1191   // Write data to output file.
1192   void
1193   do_write(Output_file*);
1194
1195   // Return required alignment of this.
1196   uint64_t
1197   do_addralign() const
1198   {
1199     if (this->is_stub_table_owner())
1200       return std::max(this->stub_table_->addralign(),
1201                       static_cast<uint64_t>(this->original_addralign_));
1202     else
1203       return this->original_addralign_;
1204   }
1205
1206   // Finalize data size.
1207   void
1208   set_final_data_size();
1209
1210   // Reset address and file offset.
1211   void
1212   do_reset_address_and_file_offset();
1213
1214   // Output offset.
1215   bool
1216   do_output_offset(const Relobj* object, unsigned int shndx,
1217                    section_offset_type offset,
1218                    section_offset_type* poutput) const
1219   {
1220     if ((object == this->relobj())
1221         && (shndx == this->shndx())
1222         && (offset >= 0)
1223         && (offset <=
1224             convert_types<section_offset_type, uint32_t>(this->original_size_)))
1225       {
1226         *poutput = offset;
1227         return true;
1228       }
1229     else
1230       return false;
1231   }
1232
1233  private:
1234   // Copying is not allowed.
1235   Arm_input_section(const Arm_input_section&);
1236   Arm_input_section& operator=(const Arm_input_section&);
1237
1238   // Address alignment of the original input section.
1239   uint32_t original_addralign_;
1240   // Section size of the original input section.
1241   uint32_t original_size_;
1242   // Stub table.
1243   Stub_table<big_endian>* stub_table_;
1244   // Original section contents.  We have to make a copy here since the file
1245   // containing the original section may not be locked when we need to access
1246   // the contents.
1247   unsigned char* original_contents_;
1248 };
1249
1250 // Arm_exidx_fixup class.  This is used to define a number of methods
1251 // and keep states for fixing up EXIDX coverage.
1252
1253 class Arm_exidx_fixup
1254 {
1255  public:
1256   Arm_exidx_fixup(Output_section* exidx_output_section,
1257                   bool merge_exidx_entries = true)
1258     : exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE),
1259       last_inlined_entry_(0), last_input_section_(NULL),
1260       section_offset_map_(NULL), first_output_text_section_(NULL),
1261       merge_exidx_entries_(merge_exidx_entries)
1262   { }
1263
1264   ~Arm_exidx_fixup()
1265   { delete this->section_offset_map_; }
1266
1267   // Process an EXIDX section for entry merging.  SECTION_CONTENTS points
1268   // to the EXIDX contents and SECTION_SIZE is the size of the contents. Return
1269   // number of bytes to be deleted in output.  If parts of the input EXIDX
1270   // section are merged a heap allocated Arm_exidx_section_offset_map is store
1271   // in the located PSECTION_OFFSET_MAP.   The caller owns the map and is
1272   // responsible for releasing it.
1273   template<bool big_endian>
1274   uint32_t
1275   process_exidx_section(const Arm_exidx_input_section* exidx_input_section,
1276                         const unsigned char* section_contents,
1277                         section_size_type section_size,
1278                         Arm_exidx_section_offset_map** psection_offset_map);
1279
1280   // Append an EXIDX_CANTUNWIND entry pointing at the end of the last
1281   // input section, if there is not one already.
1282   void
1283   add_exidx_cantunwind_as_needed();
1284
1285   // Return the output section for the text section which is linked to the
1286   // first exidx input in output.
1287   Output_section*
1288   first_output_text_section() const
1289   { return this->first_output_text_section_; }
1290
1291  private:
1292   // Copying is not allowed.
1293   Arm_exidx_fixup(const Arm_exidx_fixup&);
1294   Arm_exidx_fixup& operator=(const Arm_exidx_fixup&);
1295
1296   // Type of EXIDX unwind entry.
1297   enum Unwind_type
1298   {
1299     // No type.
1300     UT_NONE,
1301     // EXIDX_CANTUNWIND.
1302     UT_EXIDX_CANTUNWIND,
1303     // Inlined entry.
1304     UT_INLINED_ENTRY,
1305     // Normal entry.
1306     UT_NORMAL_ENTRY,
1307   };
1308
1309   // Process an EXIDX entry.  We only care about the second word of the
1310   // entry.  Return true if the entry can be deleted.
1311   bool
1312   process_exidx_entry(uint32_t second_word);
1313
1314   // Update the current section offset map during EXIDX section fix-up.
1315   // If there is no map, create one.  INPUT_OFFSET is the offset of a
1316   // reference point, DELETED_BYTES is the number of deleted by in the
1317   // section so far.  If DELETE_ENTRY is true, the reference point and
1318   // all offsets after the previous reference point are discarded.
1319   void
1320   update_offset_map(section_offset_type input_offset,
1321                     section_size_type deleted_bytes, bool delete_entry);
1322
1323   // EXIDX output section.
1324   Output_section* exidx_output_section_;
1325   // Unwind type of the last EXIDX entry processed.
1326   Unwind_type last_unwind_type_;
1327   // Last seen inlined EXIDX entry.
1328   uint32_t last_inlined_entry_;
1329   // Last processed EXIDX input section.
1330   const Arm_exidx_input_section* last_input_section_;
1331   // Section offset map created in process_exidx_section.
1332   Arm_exidx_section_offset_map* section_offset_map_;
1333   // Output section for the text section which is linked to the first exidx
1334   // input in output.
1335   Output_section* first_output_text_section_;
1336
1337   bool merge_exidx_entries_;
1338 };
1339
1340 // Arm output section class.  This is defined mainly to add a number of
1341 // stub generation methods.
1342
1343 template<bool big_endian>
1344 class Arm_output_section : public Output_section
1345 {
1346  public:
1347   typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list;
1348
1349   // We need to force SHF_LINK_ORDER in a SHT_ARM_EXIDX section.
1350   Arm_output_section(const char* name, elfcpp::Elf_Word type,
1351                      elfcpp::Elf_Xword flags)
1352     : Output_section(name, type,
1353                      (type == elfcpp::SHT_ARM_EXIDX
1354                       ? flags | elfcpp::SHF_LINK_ORDER
1355                       : flags))
1356   {
1357     if (type == elfcpp::SHT_ARM_EXIDX)
1358       this->set_always_keeps_input_sections();
1359   }
1360
1361   ~Arm_output_section()
1362   { }
1363
1364   // Group input sections for stub generation.
1365   void
1366   group_sections(section_size_type, bool, Target_arm<big_endian>*, const Task*);
1367
1368   // Downcast a base pointer to an Arm_output_section pointer.  This is
1369   // not type-safe but we only use Arm_output_section not the base class.
1370   static Arm_output_section<big_endian>*
1371   as_arm_output_section(Output_section* os)
1372   { return static_cast<Arm_output_section<big_endian>*>(os); }
1373
1374   // Append all input text sections in this into LIST.
1375   void
1376   append_text_sections_to_list(Text_section_list* list);
1377
1378   // Fix EXIDX coverage of this EXIDX output section.  SORTED_TEXT_SECTION
1379   // is a list of text input sections sorted in ascending order of their
1380   // output addresses.
1381   void
1382   fix_exidx_coverage(Layout* layout,
1383                      const Text_section_list& sorted_text_section,
1384                      Symbol_table* symtab,
1385                      bool merge_exidx_entries,
1386                      const Task* task);
1387
1388   // Link an EXIDX section into its corresponding text section.
1389   void
1390   set_exidx_section_link();
1391
1392  private:
1393   // For convenience.
1394   typedef Output_section::Input_section Input_section;
1395   typedef Output_section::Input_section_list Input_section_list;
1396
1397   // Create a stub group.
1398   void create_stub_group(Input_section_list::const_iterator,
1399                          Input_section_list::const_iterator,
1400                          Input_section_list::const_iterator,
1401                          Target_arm<big_endian>*,
1402                          std::vector<Output_relaxed_input_section*>*,
1403                          const Task* task);
1404 };
1405
1406 // Arm_exidx_input_section class.  This represents an EXIDX input section.
1407
1408 class Arm_exidx_input_section
1409 {
1410  public:
1411   static const section_offset_type invalid_offset =
1412     static_cast<section_offset_type>(-1);
1413
1414   Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1415                           unsigned int link, uint32_t size,
1416                           uint32_t addralign, uint32_t text_size)
1417     : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1418       addralign_(addralign), text_size_(text_size), has_errors_(false)
1419   { }
1420
1421   ~Arm_exidx_input_section()
1422   { }
1423
1424   // Accessors:  This is a read-only class.
1425
1426   // Return the object containing this EXIDX input section.
1427   Relobj*
1428   relobj() const
1429   { return this->relobj_; }
1430
1431   // Return the section index of this EXIDX input section.
1432   unsigned int
1433   shndx() const
1434   { return this->shndx_; }
1435
1436   // Return the section index of linked text section in the same object.
1437   unsigned int
1438   link() const
1439   { return this->link_; }
1440
1441   // Return size of the EXIDX input section.
1442   uint32_t
1443   size() const
1444   { return this->size_; }
1445
1446   // Return address alignment of EXIDX input section.
1447   uint32_t
1448   addralign() const
1449   { return this->addralign_; }
1450
1451   // Return size of the associated text input section.
1452   uint32_t
1453   text_size() const
1454   { return this->text_size_; }
1455
1456   // Whether there are any errors in the EXIDX input section.
1457   bool
1458   has_errors() const
1459   { return this->has_errors_; }
1460
1461   // Set has-errors flag.
1462   void
1463   set_has_errors()
1464   { this->has_errors_ = true; }
1465
1466  private:
1467   // Object containing this.
1468   Relobj* relobj_;
1469   // Section index of this.
1470   unsigned int shndx_;
1471   // text section linked to this in the same object.
1472   unsigned int link_;
1473   // Size of this.  For ARM 32-bit is sufficient.
1474   uint32_t size_;
1475   // Address alignment of this.  For ARM 32-bit is sufficient.
1476   uint32_t addralign_;
1477   // Size of associated text section.
1478   uint32_t text_size_;
1479   // Whether this has any errors.
1480   bool has_errors_;
1481 };
1482
1483 // Arm_relobj class.
1484
1485 template<bool big_endian>
1486 class Arm_relobj : public Sized_relobj_file<32, big_endian>
1487 {
1488  public:
1489   static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1490
1491   Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1492              const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1493     : Sized_relobj_file<32, big_endian>(name, input_file, offset, ehdr),
1494       stub_tables_(), local_symbol_is_thumb_function_(),
1495       attributes_section_data_(NULL), mapping_symbols_info_(),
1496       section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1497       output_local_symbol_count_needs_update_(false),
1498       merge_flags_and_attributes_(true)
1499   { }
1500
1501   ~Arm_relobj()
1502   { delete this->attributes_section_data_; }
1503
1504   // Return the stub table of the SHNDX-th section if there is one.
1505   Stub_table<big_endian>*
1506   stub_table(unsigned int shndx) const
1507   {
1508     gold_assert(shndx < this->stub_tables_.size());
1509     return this->stub_tables_[shndx];
1510   }
1511
1512   // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1513   void
1514   set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1515   {
1516     gold_assert(shndx < this->stub_tables_.size());
1517     this->stub_tables_[shndx] = stub_table;
1518   }
1519
1520   // Whether a local symbol is a THUMB function.  R_SYM is the symbol table
1521   // index.  This is only valid after do_count_local_symbol is called.
1522   bool
1523   local_symbol_is_thumb_function(unsigned int r_sym) const
1524   {
1525     gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1526     return this->local_symbol_is_thumb_function_[r_sym];
1527   }
1528
1529   // Scan all relocation sections for stub generation.
1530   void
1531   scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1532                           const Layout*);
1533
1534   // Convert regular input section with index SHNDX to a relaxed section.
1535   void
1536   convert_input_section_to_relaxed_section(unsigned shndx)
1537   {
1538     // The stubs have relocations and we need to process them after writing
1539     // out the stubs.  So relocation now must follow section write.
1540     this->set_section_offset(shndx, -1ULL);
1541     this->set_relocs_must_follow_section_writes();
1542   }
1543
1544   // Downcast a base pointer to an Arm_relobj pointer.  This is
1545   // not type-safe but we only use Arm_relobj not the base class.
1546   static Arm_relobj<big_endian>*
1547   as_arm_relobj(Relobj* relobj)
1548   { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1549
1550   // Processor-specific flags in ELF file header.  This is valid only after
1551   // reading symbols.
1552   elfcpp::Elf_Word
1553   processor_specific_flags() const
1554   { return this->processor_specific_flags_; }
1555
1556   // Attribute section data  This is the contents of the .ARM.attribute section
1557   // if there is one.
1558   const Attributes_section_data*
1559   attributes_section_data() const
1560   { return this->attributes_section_data_; }
1561
1562   // Mapping symbol location.
1563   typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1564
1565   // Functor for STL container.
1566   struct Mapping_symbol_position_less
1567   {
1568     bool
1569     operator()(const Mapping_symbol_position& p1,
1570                const Mapping_symbol_position& p2) const
1571     {
1572       return (p1.first < p2.first
1573               || (p1.first == p2.first && p1.second < p2.second));
1574     }
1575   };
1576
1577   // We only care about the first character of a mapping symbol, so
1578   // we only store that instead of the whole symbol name.
1579   typedef std::map<Mapping_symbol_position, char,
1580                    Mapping_symbol_position_less> Mapping_symbols_info;
1581
1582   // Whether a section contains any Cortex-A8 workaround.
1583   bool
1584   section_has_cortex_a8_workaround(unsigned int shndx) const
1585   {
1586     return (this->section_has_cortex_a8_workaround_ != NULL
1587             && (*this->section_has_cortex_a8_workaround_)[shndx]);
1588   }
1589
1590   // Mark a section that has Cortex-A8 workaround.
1591   void
1592   mark_section_for_cortex_a8_workaround(unsigned int shndx)
1593   {
1594     if (this->section_has_cortex_a8_workaround_ == NULL)
1595       this->section_has_cortex_a8_workaround_ =
1596         new std::vector<bool>(this->shnum(), false);
1597     (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1598   }
1599
1600   // Return the EXIDX section of an text section with index SHNDX or NULL
1601   // if the text section has no associated EXIDX section.
1602   const Arm_exidx_input_section*
1603   exidx_input_section_by_link(unsigned int shndx) const
1604   {
1605     Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1606     return ((p != this->exidx_section_map_.end()
1607              && p->second->link() == shndx)
1608             ? p->second
1609             : NULL);
1610   }
1611
1612   // Return the EXIDX section with index SHNDX or NULL if there is none.
1613   const Arm_exidx_input_section*
1614   exidx_input_section_by_shndx(unsigned shndx) const
1615   {
1616     Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1617     return ((p != this->exidx_section_map_.end()
1618              && p->second->shndx() == shndx)
1619             ? p->second
1620             : NULL);
1621   }
1622
1623   // Whether output local symbol count needs updating.
1624   bool
1625   output_local_symbol_count_needs_update() const
1626   { return this->output_local_symbol_count_needs_update_; }
1627
1628   // Set output_local_symbol_count_needs_update flag to be true.
1629   void
1630   set_output_local_symbol_count_needs_update()
1631   { this->output_local_symbol_count_needs_update_ = true; }
1632
1633   // Update output local symbol count at the end of relaxation.
1634   void
1635   update_output_local_symbol_count();
1636
1637   // Whether we want to merge processor-specific flags and attributes.
1638   bool
1639   merge_flags_and_attributes() const
1640   { return this->merge_flags_and_attributes_; }
1641
1642   // Export list of EXIDX section indices.
1643   void
1644   get_exidx_shndx_list(std::vector<unsigned int>* list) const
1645   {
1646     list->clear();
1647     for (Exidx_section_map::const_iterator p = this->exidx_section_map_.begin();
1648          p != this->exidx_section_map_.end();
1649          ++p)
1650       {
1651         if (p->second->shndx() == p->first)
1652           list->push_back(p->first);
1653       }
1654     // Sort list to make result independent of implementation of map.
1655     std::sort(list->begin(), list->end());
1656   }
1657
1658  protected:
1659   // Post constructor setup.
1660   void
1661   do_setup()
1662   {
1663     // Call parent's setup method.
1664     Sized_relobj_file<32, big_endian>::do_setup();
1665
1666     // Initialize look-up tables.
1667     Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1668     this->stub_tables_.swap(empty_stub_table_list);
1669   }
1670
1671   // Count the local symbols.
1672   void
1673   do_count_local_symbols(Stringpool_template<char>*,
1674                          Stringpool_template<char>*);
1675
1676   void
1677   do_relocate_sections(
1678       const Symbol_table* symtab, const Layout* layout,
1679       const unsigned char* pshdrs, Output_file* of,
1680       typename Sized_relobj_file<32, big_endian>::Views* pivews);
1681
1682   // Read the symbol information.
1683   void
1684   do_read_symbols(Read_symbols_data* sd);
1685
1686   // Process relocs for garbage collection.
1687   void
1688   do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1689
1690  private:
1691
1692   // Whether a section needs to be scanned for relocation stubs.
1693   bool
1694   section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1695                                     const Relobj::Output_sections&,
1696                                     const Symbol_table*, const unsigned char*);
1697
1698   // Whether a section is a scannable text section.
1699   bool
1700   section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1701                        const Output_section*, const Symbol_table*);
1702
1703   // Whether a section needs to be scanned for the Cortex-A8 erratum.
1704   bool
1705   section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1706                                         unsigned int, Output_section*,
1707                                         const Symbol_table*);
1708
1709   // Scan a section for the Cortex-A8 erratum.
1710   void
1711   scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1712                                      unsigned int, Output_section*,
1713                                      Target_arm<big_endian>*);
1714
1715   // Find the linked text section of an EXIDX section by looking at the
1716   // first relocation of the EXIDX section.  PSHDR points to the section
1717   // headers of a relocation section and PSYMS points to the local symbols.
1718   // PSHNDX points to a location storing the text section index if found.
1719   // Return whether we can find the linked section.
1720   bool
1721   find_linked_text_section(const unsigned char* pshdr,
1722                            const unsigned char* psyms, unsigned int* pshndx);
1723
1724   //
1725   // Make a new Arm_exidx_input_section object for EXIDX section with
1726   // index SHNDX and section header SHDR.  TEXT_SHNDX is the section
1727   // index of the linked text section.
1728   void
1729   make_exidx_input_section(unsigned int shndx,
1730                            const elfcpp::Shdr<32, big_endian>& shdr,
1731                            unsigned int text_shndx,
1732                            const elfcpp::Shdr<32, big_endian>& text_shdr);
1733
1734   // Return the output address of either a plain input section or a
1735   // relaxed input section.  SHNDX is the section index.
1736   Arm_address
1737   simple_input_section_output_address(unsigned int, Output_section*);
1738
1739   typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1740   typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1741     Exidx_section_map;
1742
1743   // List of stub tables.
1744   Stub_table_list stub_tables_;
1745   // Bit vector to tell if a local symbol is a thumb function or not.
1746   // This is only valid after do_count_local_symbol is called.
1747   std::vector<bool> local_symbol_is_thumb_function_;
1748   // processor-specific flags in ELF file header.
1749   elfcpp::Elf_Word processor_specific_flags_;
1750   // Object attributes if there is an .ARM.attributes section or NULL.
1751   Attributes_section_data* attributes_section_data_;
1752   // Mapping symbols information.
1753   Mapping_symbols_info mapping_symbols_info_;
1754   // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1755   std::vector<bool>* section_has_cortex_a8_workaround_;
1756   // Map a text section to its associated .ARM.exidx section, if there is one.
1757   Exidx_section_map exidx_section_map_;
1758   // Whether output local symbol count needs updating.
1759   bool output_local_symbol_count_needs_update_;
1760   // Whether we merge processor flags and attributes of this object to
1761   // output.
1762   bool merge_flags_and_attributes_;
1763 };
1764
1765 // Arm_dynobj class.
1766
1767 template<bool big_endian>
1768 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1769 {
1770  public:
1771   Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1772              const elfcpp::Ehdr<32, big_endian>& ehdr)
1773     : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1774       processor_specific_flags_(0), attributes_section_data_(NULL)
1775   { }
1776
1777   ~Arm_dynobj()
1778   { delete this->attributes_section_data_; }
1779
1780   // Downcast a base pointer to an Arm_relobj pointer.  This is
1781   // not type-safe but we only use Arm_relobj not the base class.
1782   static Arm_dynobj<big_endian>*
1783   as_arm_dynobj(Dynobj* dynobj)
1784   { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1785
1786   // Processor-specific flags in ELF file header.  This is valid only after
1787   // reading symbols.
1788   elfcpp::Elf_Word
1789   processor_specific_flags() const
1790   { return this->processor_specific_flags_; }
1791
1792   // Attributes section data.
1793   const Attributes_section_data*
1794   attributes_section_data() const
1795   { return this->attributes_section_data_; }
1796
1797  protected:
1798   // Read the symbol information.
1799   void
1800   do_read_symbols(Read_symbols_data* sd);
1801
1802  private:
1803   // processor-specific flags in ELF file header.
1804   elfcpp::Elf_Word processor_specific_flags_;
1805   // Object attributes if there is an .ARM.attributes section or NULL.
1806   Attributes_section_data* attributes_section_data_;
1807 };
1808
1809 // Functor to read reloc addends during stub generation.
1810
1811 template<int sh_type, bool big_endian>
1812 struct Stub_addend_reader
1813 {
1814   // Return the addend for a relocation of a particular type.  Depending
1815   // on whether this is a REL or RELA relocation, read the addend from a
1816   // view or from a Reloc object.
1817   elfcpp::Elf_types<32>::Elf_Swxword
1818   operator()(
1819     unsigned int /* r_type */,
1820     const unsigned char* /* view */,
1821     const typename Reloc_types<sh_type,
1822                                32, big_endian>::Reloc& /* reloc */) const;
1823 };
1824
1825 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1826
1827 template<bool big_endian>
1828 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1829 {
1830   elfcpp::Elf_types<32>::Elf_Swxword
1831   operator()(
1832     unsigned int,
1833     const unsigned char*,
1834     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1835 };
1836
1837 // Specialized Stub_addend_reader for RELA type relocation sections.
1838 // We currently do not handle RELA type relocation sections but it is trivial
1839 // to implement the addend reader.  This is provided for completeness and to
1840 // make it easier to add support for RELA relocation sections in the future.
1841
1842 template<bool big_endian>
1843 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1844 {
1845   elfcpp::Elf_types<32>::Elf_Swxword
1846   operator()(
1847     unsigned int,
1848     const unsigned char*,
1849     const typename Reloc_types<elfcpp::SHT_RELA, 32,
1850                                big_endian>::Reloc& reloc) const
1851   { return reloc.get_r_addend(); }
1852 };
1853
1854 // Cortex_a8_reloc class.  We keep record of relocation that may need
1855 // the Cortex-A8 erratum workaround.
1856
1857 class Cortex_a8_reloc
1858 {
1859  public:
1860   Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1861                   Arm_address destination)
1862     : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1863   { }
1864
1865   ~Cortex_a8_reloc()
1866   { }
1867
1868   // Accessors:  This is a read-only class.
1869
1870   // Return the relocation stub associated with this relocation if there is
1871   // one.
1872   const Reloc_stub*
1873   reloc_stub() const
1874   { return this->reloc_stub_; }
1875
1876   // Return the relocation type.
1877   unsigned int
1878   r_type() const
1879   { return this->r_type_; }
1880
1881   // Return the destination address of the relocation.  LSB stores the THUMB
1882   // bit.
1883   Arm_address
1884   destination() const
1885   { return this->destination_; }
1886
1887  private:
1888   // Associated relocation stub if there is one, or NULL.
1889   const Reloc_stub* reloc_stub_;
1890   // Relocation type.
1891   unsigned int r_type_;
1892   // Destination address of this relocation.  LSB is used to distinguish
1893   // ARM/THUMB mode.
1894   Arm_address destination_;
1895 };
1896
1897 // Arm_output_data_got class.  We derive this from Output_data_got to add
1898 // extra methods to handle TLS relocations in a static link.
1899
1900 template<bool big_endian>
1901 class Arm_output_data_got : public Output_data_got<32, big_endian>
1902 {
1903  public:
1904   Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1905     : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1906   { }
1907
1908   // Add a static entry for the GOT entry at OFFSET.  GSYM is a global
1909   // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1910   // applied in a static link.
1911   void
1912   add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1913   { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1914
1915   // Add a static reloc for the GOT entry at OFFSET.  RELOBJ is an object
1916   // defining a local symbol with INDEX.  R_TYPE is the code of a dynamic
1917   // relocation that needs to be applied in a static link.
1918   void
1919   add_static_reloc(unsigned int got_offset, unsigned int r_type,
1920                    Sized_relobj_file<32, big_endian>* relobj,
1921                    unsigned int index)
1922   {
1923     this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1924                                                 index));
1925   }
1926
1927   // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
1928   // The first one is initialized to be 1, which is the module index for
1929   // the main executable and the second one 0.  A reloc of the type
1930   // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1931   // be applied by gold.  GSYM is a global symbol.
1932   void
1933   add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1934
1935   // Same as the above but for a local symbol in OBJECT with INDEX.
1936   void
1937   add_tls_gd32_with_static_reloc(unsigned int got_type,
1938                                  Sized_relobj_file<32, big_endian>* object,
1939                                  unsigned int index);
1940
1941  protected:
1942   // Write out the GOT table.
1943   void
1944   do_write(Output_file*);
1945
1946  private:
1947   // This class represent dynamic relocations that need to be applied by
1948   // gold because we are using TLS relocations in a static link.
1949   class Static_reloc
1950   {
1951    public:
1952     Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1953       : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1954     { this->u_.global.symbol = gsym; }
1955
1956     Static_reloc(unsigned int got_offset, unsigned int r_type,
1957           Sized_relobj_file<32, big_endian>* relobj, unsigned int index)
1958       : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1959     {
1960       this->u_.local.relobj = relobj;
1961       this->u_.local.index = index;
1962     }
1963
1964     // Return the GOT offset.
1965     unsigned int
1966     got_offset() const
1967     { return this->got_offset_; }
1968
1969     // Relocation type.
1970     unsigned int
1971     r_type() const
1972     { return this->r_type_; }
1973
1974     // Whether the symbol is global or not.
1975     bool
1976     symbol_is_global() const
1977     { return this->symbol_is_global_; }
1978
1979     // For a relocation against a global symbol, the global symbol.
1980     Symbol*
1981     symbol() const
1982     {
1983       gold_assert(this->symbol_is_global_);
1984       return this->u_.global.symbol;
1985     }
1986
1987     // For a relocation against a local symbol, the defining object.
1988     Sized_relobj_file<32, big_endian>*
1989     relobj() const
1990     {
1991       gold_assert(!this->symbol_is_global_);
1992       return this->u_.local.relobj;
1993     }
1994
1995     // For a relocation against a local symbol, the local symbol index.
1996     unsigned int
1997     index() const
1998     {
1999       gold_assert(!this->symbol_is_global_);
2000       return this->u_.local.index;
2001     }
2002
2003    private:
2004     // GOT offset of the entry to which this relocation is applied.
2005     unsigned int got_offset_;
2006     // Type of relocation.
2007     unsigned int r_type_;
2008     // Whether this relocation is against a global symbol.
2009     bool symbol_is_global_;
2010     // A global or local symbol.
2011     union
2012     {
2013       struct
2014       {
2015         // For a global symbol, the symbol itself.
2016         Symbol* symbol;
2017       } global;
2018       struct
2019       {
2020         // For a local symbol, the object defining object.
2021         Sized_relobj_file<32, big_endian>* relobj;
2022         // For a local symbol, the symbol index.
2023         unsigned int index;
2024       } local;
2025     } u_;
2026   };
2027
2028   // Symbol table of the output object.
2029   Symbol_table* symbol_table_;
2030   // Layout of the output object.
2031   Layout* layout_;
2032   // Static relocs to be applied to the GOT.
2033   std::vector<Static_reloc> static_relocs_;
2034 };
2035
2036 // The ARM target has many relocation types with odd-sizes or noncontiguous
2037 // bits.  The default handling of relocatable relocation cannot process these
2038 // relocations.  So we have to extend the default code.
2039
2040 template<bool big_endian, int sh_type, typename Classify_reloc>
2041 class Arm_scan_relocatable_relocs :
2042   public Default_scan_relocatable_relocs<sh_type, Classify_reloc>
2043 {
2044  public:
2045   // Return the strategy to use for a local symbol which is a section
2046   // symbol, given the relocation type.
2047   inline Relocatable_relocs::Reloc_strategy
2048   local_section_strategy(unsigned int r_type, Relobj*)
2049   {
2050     if (sh_type == elfcpp::SHT_RELA)
2051       return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
2052     else
2053       {
2054         if (r_type == elfcpp::R_ARM_TARGET1
2055             || r_type == elfcpp::R_ARM_TARGET2)
2056           {
2057             const Target_arm<big_endian>* arm_target =
2058               Target_arm<big_endian>::default_target();
2059             r_type = arm_target->get_real_reloc_type(r_type);
2060           }
2061
2062         switch(r_type)
2063           {
2064           // Relocations that write nothing.  These exclude R_ARM_TARGET1
2065           // and R_ARM_TARGET2.
2066           case elfcpp::R_ARM_NONE:
2067           case elfcpp::R_ARM_V4BX:
2068           case elfcpp::R_ARM_TLS_GOTDESC:
2069           case elfcpp::R_ARM_TLS_CALL:
2070           case elfcpp::R_ARM_TLS_DESCSEQ:
2071           case elfcpp::R_ARM_THM_TLS_CALL:
2072           case elfcpp::R_ARM_GOTRELAX:
2073           case elfcpp::R_ARM_GNU_VTENTRY:
2074           case elfcpp::R_ARM_GNU_VTINHERIT:
2075           case elfcpp::R_ARM_THM_TLS_DESCSEQ16:
2076           case elfcpp::R_ARM_THM_TLS_DESCSEQ32:
2077             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
2078           // These should have been converted to something else above.
2079           case elfcpp::R_ARM_TARGET1:
2080           case elfcpp::R_ARM_TARGET2:
2081             gold_unreachable();
2082           // Relocations that write full 32 bits and
2083           // have alignment of 1.
2084           case elfcpp::R_ARM_ABS32:
2085           case elfcpp::R_ARM_REL32:
2086           case elfcpp::R_ARM_SBREL32:
2087           case elfcpp::R_ARM_GOTOFF32:
2088           case elfcpp::R_ARM_BASE_PREL:
2089           case elfcpp::R_ARM_GOT_BREL:
2090           case elfcpp::R_ARM_BASE_ABS:
2091           case elfcpp::R_ARM_ABS32_NOI:
2092           case elfcpp::R_ARM_REL32_NOI:
2093           case elfcpp::R_ARM_PLT32_ABS:
2094           case elfcpp::R_ARM_GOT_ABS:
2095           case elfcpp::R_ARM_GOT_PREL:
2096           case elfcpp::R_ARM_TLS_GD32:
2097           case elfcpp::R_ARM_TLS_LDM32:
2098           case elfcpp::R_ARM_TLS_LDO32:
2099           case elfcpp::R_ARM_TLS_IE32:
2100           case elfcpp::R_ARM_TLS_LE32:
2101             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED;
2102           default:
2103             // For all other static relocations, return RELOC_SPECIAL.
2104             return Relocatable_relocs::RELOC_SPECIAL;
2105           }
2106       }
2107   }
2108 };
2109
2110 template<bool big_endian>
2111 class Target_arm : public Sized_target<32, big_endian>
2112 {
2113  public:
2114   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
2115     Reloc_section;
2116
2117   // When were are relocating a stub, we pass this as the relocation number.
2118   static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
2119
2120   Target_arm(const Target::Target_info* info = &arm_info)
2121     : Sized_target<32, big_endian>(info),
2122       got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
2123       copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL),
2124       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2125       stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2126       should_force_pic_veneer_(false),
2127       arm_input_section_map_(), attributes_section_data_(NULL),
2128       fix_cortex_a8_(false), cortex_a8_relocs_info_()
2129   { }
2130
2131   // Whether we force PCI branch veneers.
2132   bool
2133   should_force_pic_veneer() const
2134   { return this->should_force_pic_veneer_; }
2135
2136   // Set PIC veneer flag.
2137   void
2138   set_should_force_pic_veneer(bool value)
2139   { this->should_force_pic_veneer_ = value; }
2140
2141   // Whether we use THUMB-2 instructions.
2142   bool
2143   using_thumb2() const
2144   {
2145     Object_attribute* attr =
2146       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2147     int arch = attr->int_value();
2148     return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2149   }
2150
2151   // Whether we use THUMB/THUMB-2 instructions only.
2152   bool
2153   using_thumb_only() const
2154   {
2155     Object_attribute* attr =
2156       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2157
2158     if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M
2159         || attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M)
2160       return true;
2161     if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2162         && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2163       return false;
2164     attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2165     return attr->int_value() == 'M';
2166   }
2167
2168   // Whether we have an NOP instruction.  If not, use mov r0, r0 instead.
2169   bool
2170   may_use_arm_nop() const
2171   {
2172     Object_attribute* attr =
2173       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2174     int arch = attr->int_value();
2175     return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2176             || arch == elfcpp::TAG_CPU_ARCH_V6K
2177             || arch == elfcpp::TAG_CPU_ARCH_V7
2178             || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2179   }
2180
2181   // Whether we have THUMB-2 NOP.W instruction.
2182   bool
2183   may_use_thumb2_nop() const
2184   {
2185     Object_attribute* attr =
2186       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2187     int arch = attr->int_value();
2188     return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2189             || arch == elfcpp::TAG_CPU_ARCH_V7
2190             || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2191   }
2192
2193   // Whether we have v4T interworking instructions available.
2194   bool
2195   may_use_v4t_interworking() const
2196   {
2197     Object_attribute* attr =
2198       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2199     int arch = attr->int_value();
2200     return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2201             && arch != elfcpp::TAG_CPU_ARCH_V4);
2202   }
2203
2204   // Whether we have v5T interworking instructions available.
2205   bool
2206   may_use_v5t_interworking() const
2207   {
2208     Object_attribute* attr =
2209       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2210     int arch = attr->int_value();
2211     if (parameters->options().fix_arm1176())
2212       return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2213               || arch == elfcpp::TAG_CPU_ARCH_V7
2214               || arch == elfcpp::TAG_CPU_ARCH_V6_M
2215               || arch == elfcpp::TAG_CPU_ARCH_V6S_M
2216               || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2217     else
2218       return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2219               && arch != elfcpp::TAG_CPU_ARCH_V4
2220               && arch != elfcpp::TAG_CPU_ARCH_V4T);
2221   }
2222
2223   // Process the relocations to determine unreferenced sections for
2224   // garbage collection.
2225   void
2226   gc_process_relocs(Symbol_table* symtab,
2227                     Layout* layout,
2228                     Sized_relobj_file<32, big_endian>* object,
2229                     unsigned int data_shndx,
2230                     unsigned int sh_type,
2231                     const unsigned char* prelocs,
2232                     size_t reloc_count,
2233                     Output_section* output_section,
2234                     bool needs_special_offset_handling,
2235                     size_t local_symbol_count,
2236                     const unsigned char* plocal_symbols);
2237
2238   // Scan the relocations to look for symbol adjustments.
2239   void
2240   scan_relocs(Symbol_table* symtab,
2241               Layout* layout,
2242               Sized_relobj_file<32, big_endian>* object,
2243               unsigned int data_shndx,
2244               unsigned int sh_type,
2245               const unsigned char* prelocs,
2246               size_t reloc_count,
2247               Output_section* output_section,
2248               bool needs_special_offset_handling,
2249               size_t local_symbol_count,
2250               const unsigned char* plocal_symbols);
2251
2252   // Finalize the sections.
2253   void
2254   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2255
2256   // Return the value to use for a dynamic symbol which requires special
2257   // treatment.
2258   uint64_t
2259   do_dynsym_value(const Symbol*) const;
2260
2261   // Relocate a section.
2262   void
2263   relocate_section(const Relocate_info<32, big_endian>*,
2264                    unsigned int sh_type,
2265                    const unsigned char* prelocs,
2266                    size_t reloc_count,
2267                    Output_section* output_section,
2268                    bool needs_special_offset_handling,
2269                    unsigned char* view,
2270                    Arm_address view_address,
2271                    section_size_type view_size,
2272                    const Reloc_symbol_changes*);
2273
2274   // Scan the relocs during a relocatable link.
2275   void
2276   scan_relocatable_relocs(Symbol_table* symtab,
2277                           Layout* layout,
2278                           Sized_relobj_file<32, big_endian>* object,
2279                           unsigned int data_shndx,
2280                           unsigned int sh_type,
2281                           const unsigned char* prelocs,
2282                           size_t reloc_count,
2283                           Output_section* output_section,
2284                           bool needs_special_offset_handling,
2285                           size_t local_symbol_count,
2286                           const unsigned char* plocal_symbols,
2287                           Relocatable_relocs*);
2288
2289   // Emit relocations for a section.
2290   void
2291   relocate_relocs(const Relocate_info<32, big_endian>*,
2292                   unsigned int sh_type,
2293                   const unsigned char* prelocs,
2294                   size_t reloc_count,
2295                   Output_section* output_section,
2296                   typename elfcpp::Elf_types<32>::Elf_Off
2297                     offset_in_output_section,
2298                   const Relocatable_relocs*,
2299                   unsigned char* view,
2300                   Arm_address view_address,
2301                   section_size_type view_size,
2302                   unsigned char* reloc_view,
2303                   section_size_type reloc_view_size);
2304
2305   // Perform target-specific processing in a relocatable link.  This is
2306   // only used if we use the relocation strategy RELOC_SPECIAL.
2307   void
2308   relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2309                                unsigned int sh_type,
2310                                const unsigned char* preloc_in,
2311                                size_t relnum,
2312                                Output_section* output_section,
2313                                typename elfcpp::Elf_types<32>::Elf_Off
2314                                  offset_in_output_section,
2315                                unsigned char* view,
2316                                typename elfcpp::Elf_types<32>::Elf_Addr
2317                                  view_address,
2318                                section_size_type view_size,
2319                                unsigned char* preloc_out);
2320
2321   // Return whether SYM is defined by the ABI.
2322   bool
2323   do_is_defined_by_abi(const Symbol* sym) const
2324   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2325
2326   // Return whether there is a GOT section.
2327   bool
2328   has_got_section() const
2329   { return this->got_ != NULL; }
2330
2331   // Return the size of the GOT section.
2332   section_size_type
2333   got_size() const
2334   {
2335     gold_assert(this->got_ != NULL);
2336     return this->got_->data_size();
2337   }
2338
2339   // Return the number of entries in the GOT.
2340   unsigned int
2341   got_entry_count() const
2342   {
2343     if (!this->has_got_section())
2344       return 0;
2345     return this->got_size() / 4;
2346   }
2347
2348   // Return the number of entries in the PLT.
2349   unsigned int
2350   plt_entry_count() const;
2351
2352   // Return the offset of the first non-reserved PLT entry.
2353   unsigned int
2354   first_plt_entry_offset() const;
2355
2356   // Return the size of each PLT entry.
2357   unsigned int
2358   plt_entry_size() const;
2359
2360   // Map platform-specific reloc types
2361   static unsigned int
2362   get_real_reloc_type(unsigned int r_type);
2363
2364   //
2365   // Methods to support stub-generations.
2366   //
2367
2368   // Return the stub factory
2369   const Stub_factory&
2370   stub_factory() const
2371   { return this->stub_factory_; }
2372
2373   // Make a new Arm_input_section object.
2374   Arm_input_section<big_endian>*
2375   new_arm_input_section(Relobj*, unsigned int);
2376
2377   // Find the Arm_input_section object corresponding to the SHNDX-th input
2378   // section of RELOBJ.
2379   Arm_input_section<big_endian>*
2380   find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2381
2382   // Make a new Stub_table
2383   Stub_table<big_endian>*
2384   new_stub_table(Arm_input_section<big_endian>*);
2385
2386   // Scan a section for stub generation.
2387   void
2388   scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2389                          const unsigned char*, size_t, Output_section*,
2390                          bool, const unsigned char*, Arm_address,
2391                          section_size_type);
2392
2393   // Relocate a stub.
2394   void
2395   relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2396                 Output_section*, unsigned char*, Arm_address,
2397                 section_size_type);
2398
2399   // Get the default ARM target.
2400   static Target_arm<big_endian>*
2401   default_target()
2402   {
2403     gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2404                 && parameters->target().is_big_endian() == big_endian);
2405     return static_cast<Target_arm<big_endian>*>(
2406              parameters->sized_target<32, big_endian>());
2407   }
2408
2409   // Whether NAME belongs to a mapping symbol.
2410   static bool
2411   is_mapping_symbol_name(const char* name)
2412   {
2413     return (name
2414             && name[0] == '$'
2415             && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2416             && (name[2] == '\0' || name[2] == '.'));
2417   }
2418
2419   // Whether we work around the Cortex-A8 erratum.
2420   bool
2421   fix_cortex_a8() const
2422   { return this->fix_cortex_a8_; }
2423
2424   // Whether we merge exidx entries in debuginfo.
2425   bool
2426   merge_exidx_entries() const
2427   { return parameters->options().merge_exidx_entries(); }
2428
2429   // Whether we fix R_ARM_V4BX relocation.
2430   // 0 - do not fix
2431   // 1 - replace with MOV instruction (armv4 target)
2432   // 2 - make interworking veneer (>= armv4t targets only)
2433   General_options::Fix_v4bx
2434   fix_v4bx() const
2435   { return parameters->options().fix_v4bx(); }
2436
2437   // Scan a span of THUMB code section for Cortex-A8 erratum.
2438   void
2439   scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2440                                   section_size_type, section_size_type,
2441                                   const unsigned char*, Arm_address);
2442
2443   // Apply Cortex-A8 workaround to a branch.
2444   void
2445   apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2446                              unsigned char*, Arm_address);
2447
2448  protected:
2449   // Make the PLT-generator object.
2450   Output_data_plt_arm<big_endian>*
2451   make_data_plt(Layout* layout, Output_data_space* got_plt)
2452   { return this->do_make_data_plt(layout, got_plt); }
2453
2454   // Make an ELF object.
2455   Object*
2456   do_make_elf_object(const std::string&, Input_file*, off_t,
2457                      const elfcpp::Ehdr<32, big_endian>& ehdr);
2458
2459   Object*
2460   do_make_elf_object(const std::string&, Input_file*, off_t,
2461                      const elfcpp::Ehdr<32, !big_endian>&)
2462   { gold_unreachable(); }
2463
2464   Object*
2465   do_make_elf_object(const std::string&, Input_file*, off_t,
2466                       const elfcpp::Ehdr<64, false>&)
2467   { gold_unreachable(); }
2468
2469   Object*
2470   do_make_elf_object(const std::string&, Input_file*, off_t,
2471                      const elfcpp::Ehdr<64, true>&)
2472   { gold_unreachable(); }
2473
2474   // Make an output section.
2475   Output_section*
2476   do_make_output_section(const char* name, elfcpp::Elf_Word type,
2477                          elfcpp::Elf_Xword flags)
2478   { return new Arm_output_section<big_endian>(name, type, flags); }
2479
2480   void
2481   do_adjust_elf_header(unsigned char* view, int len);
2482
2483   // We only need to generate stubs, and hence perform relaxation if we are
2484   // not doing relocatable linking.
2485   bool
2486   do_may_relax() const
2487   { return !parameters->options().relocatable(); }
2488
2489   bool
2490   do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
2491
2492   // Determine whether an object attribute tag takes an integer, a
2493   // string or both.
2494   int
2495   do_attribute_arg_type(int tag) const;
2496
2497   // Reorder tags during output.
2498   int
2499   do_attributes_order(int num) const;
2500
2501   // This is called when the target is selected as the default.
2502   void
2503   do_select_as_default_target()
2504   {
2505     // No locking is required since there should only be one default target.
2506     // We cannot have both the big-endian and little-endian ARM targets
2507     // as the default.
2508     gold_assert(arm_reloc_property_table == NULL);
2509     arm_reloc_property_table = new Arm_reloc_property_table();
2510   }
2511
2512   // Virtual function which is set to return true by a target if
2513   // it can use relocation types to determine if a function's
2514   // pointer is taken.
2515   virtual bool
2516   do_can_check_for_function_pointers() const
2517   { return true; }
2518
2519   // Whether a section called SECTION_NAME may have function pointers to
2520   // sections not eligible for safe ICF folding.
2521   virtual bool
2522   do_section_may_have_icf_unsafe_pointers(const char* section_name) const
2523   {
2524     return (!is_prefix_of(".ARM.exidx", section_name)
2525             && !is_prefix_of(".ARM.extab", section_name)
2526             && Target::do_section_may_have_icf_unsafe_pointers(section_name));
2527   }
2528
2529   virtual void
2530   do_define_standard_symbols(Symbol_table*, Layout*);
2531
2532   virtual Output_data_plt_arm<big_endian>*
2533   do_make_data_plt(Layout* layout, Output_data_space* got_plt)
2534   {
2535     return new Output_data_plt_arm_standard<big_endian>(layout, got_plt);
2536   }
2537
2538  private:
2539   // The class which scans relocations.
2540   class Scan
2541   {
2542    public:
2543     Scan()
2544       : issued_non_pic_error_(false)
2545     { }
2546
2547     static inline int
2548     get_reference_flags(unsigned int r_type);
2549
2550     inline void
2551     local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2552           Sized_relobj_file<32, big_endian>* object,
2553           unsigned int data_shndx,
2554           Output_section* output_section,
2555           const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2556           const elfcpp::Sym<32, big_endian>& lsym,
2557           bool is_discarded);
2558
2559     inline void
2560     global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2561            Sized_relobj_file<32, big_endian>* object,
2562            unsigned int data_shndx,
2563            Output_section* output_section,
2564            const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2565            Symbol* gsym);
2566
2567     inline bool
2568     local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2569                                         Sized_relobj_file<32, big_endian>* ,
2570                                         unsigned int ,
2571                                         Output_section* ,
2572                                         const elfcpp::Rel<32, big_endian>& ,
2573                                         unsigned int ,
2574                                         const elfcpp::Sym<32, big_endian>&);
2575
2576     inline bool
2577     global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2578                                          Sized_relobj_file<32, big_endian>* ,
2579                                          unsigned int ,
2580                                          Output_section* ,
2581                                          const elfcpp::Rel<32, big_endian>& ,
2582                                          unsigned int , Symbol*);
2583
2584    private:
2585     static void
2586     unsupported_reloc_local(Sized_relobj_file<32, big_endian>*,
2587                             unsigned int r_type);
2588
2589     static void
2590     unsupported_reloc_global(Sized_relobj_file<32, big_endian>*,
2591                              unsigned int r_type, Symbol*);
2592
2593     void
2594     check_non_pic(Relobj*, unsigned int r_type);
2595
2596     // Almost identical to Symbol::needs_plt_entry except that it also
2597     // handles STT_ARM_TFUNC.
2598     static bool
2599     symbol_needs_plt_entry(const Symbol* sym)
2600     {
2601       // An undefined symbol from an executable does not need a PLT entry.
2602       if (sym->is_undefined() && !parameters->options().shared())
2603         return false;
2604
2605       return (!parameters->doing_static_link()
2606               && (sym->type() == elfcpp::STT_FUNC
2607                   || sym->type() == elfcpp::STT_ARM_TFUNC)
2608               && (sym->is_from_dynobj()
2609                   || sym->is_undefined()
2610                   || sym->is_preemptible()));
2611     }
2612
2613     inline bool
2614     possible_function_pointer_reloc(unsigned int r_type);
2615
2616     // Whether we have issued an error about a non-PIC compilation.
2617     bool issued_non_pic_error_;
2618   };
2619
2620   // The class which implements relocation.
2621   class Relocate
2622   {
2623    public:
2624     Relocate()
2625     { }
2626
2627     ~Relocate()
2628     { }
2629
2630     // Return whether the static relocation needs to be applied.
2631     inline bool
2632     should_apply_static_reloc(const Sized_symbol<32>* gsym,
2633                               unsigned int r_type,
2634                               bool is_32bit,
2635                               Output_section* output_section);
2636
2637     // Do a relocation.  Return false if the caller should not issue
2638     // any warnings about this relocation.
2639     inline bool
2640     relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2641              Output_section*,  size_t relnum,
2642              const elfcpp::Rel<32, big_endian>&,
2643              unsigned int r_type, const Sized_symbol<32>*,
2644              const Symbol_value<32>*,
2645              unsigned char*, Arm_address,
2646              section_size_type);
2647
2648     // Return whether we want to pass flag NON_PIC_REF for this
2649     // reloc.  This means the relocation type accesses a symbol not via
2650     // GOT or PLT.
2651     static inline bool
2652     reloc_is_non_pic(unsigned int r_type)
2653     {
2654       switch (r_type)
2655         {
2656         // These relocation types reference GOT or PLT entries explicitly.
2657         case elfcpp::R_ARM_GOT_BREL:
2658         case elfcpp::R_ARM_GOT_ABS:
2659         case elfcpp::R_ARM_GOT_PREL:
2660         case elfcpp::R_ARM_GOT_BREL12:
2661         case elfcpp::R_ARM_PLT32_ABS:
2662         case elfcpp::R_ARM_TLS_GD32:
2663         case elfcpp::R_ARM_TLS_LDM32:
2664         case elfcpp::R_ARM_TLS_IE32:
2665         case elfcpp::R_ARM_TLS_IE12GP:
2666
2667         // These relocate types may use PLT entries.
2668         case elfcpp::R_ARM_CALL:
2669         case elfcpp::R_ARM_THM_CALL:
2670         case elfcpp::R_ARM_JUMP24:
2671         case elfcpp::R_ARM_THM_JUMP24:
2672         case elfcpp::R_ARM_THM_JUMP19:
2673         case elfcpp::R_ARM_PLT32:
2674         case elfcpp::R_ARM_THM_XPC22:
2675         case elfcpp::R_ARM_PREL31:
2676         case elfcpp::R_ARM_SBREL31:
2677           return false;
2678
2679         default:
2680           return true;
2681         }
2682     }
2683
2684    private:
2685     // Do a TLS relocation.
2686     inline typename Arm_relocate_functions<big_endian>::Status
2687     relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2688                  size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2689                  const Sized_symbol<32>*, const Symbol_value<32>*,
2690                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2691                  section_size_type);
2692
2693   };
2694
2695   // A class which returns the size required for a relocation type,
2696   // used while scanning relocs during a relocatable link.
2697   class Relocatable_size_for_reloc
2698   {
2699    public:
2700     unsigned int
2701     get_size_for_reloc(unsigned int, Relobj*);
2702   };
2703
2704   // Adjust TLS relocation type based on the options and whether this
2705   // is a local symbol.
2706   static tls::Tls_optimization
2707   optimize_tls_reloc(bool is_final, int r_type);
2708
2709   // Get the GOT section, creating it if necessary.
2710   Arm_output_data_got<big_endian>*
2711   got_section(Symbol_table*, Layout*);
2712
2713   // Get the GOT PLT section.
2714   Output_data_space*
2715   got_plt_section() const
2716   {
2717     gold_assert(this->got_plt_ != NULL);
2718     return this->got_plt_;
2719   }
2720
2721   // Create a PLT entry for a global symbol.
2722   void
2723   make_plt_entry(Symbol_table*, Layout*, Symbol*);
2724
2725   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2726   void
2727   define_tls_base_symbol(Symbol_table*, Layout*);
2728
2729   // Create a GOT entry for the TLS module index.
2730   unsigned int
2731   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2732                       Sized_relobj_file<32, big_endian>* object);
2733
2734   // Get the PLT section.
2735   const Output_data_plt_arm<big_endian>*
2736   plt_section() const
2737   {
2738     gold_assert(this->plt_ != NULL);
2739     return this->plt_;
2740   }
2741
2742   // Get the dynamic reloc section, creating it if necessary.
2743   Reloc_section*
2744   rel_dyn_section(Layout*);
2745
2746   // Get the section to use for TLS_DESC relocations.
2747   Reloc_section*
2748   rel_tls_desc_section(Layout*) const;
2749
2750   // Return true if the symbol may need a COPY relocation.
2751   // References from an executable object to non-function symbols
2752   // defined in a dynamic object may need a COPY relocation.
2753   bool
2754   may_need_copy_reloc(Symbol* gsym)
2755   {
2756     return (gsym->type() != elfcpp::STT_ARM_TFUNC
2757             && gsym->may_need_copy_reloc());
2758   }
2759
2760   // Add a potential copy relocation.
2761   void
2762   copy_reloc(Symbol_table* symtab, Layout* layout,
2763              Sized_relobj_file<32, big_endian>* object,
2764              unsigned int shndx, Output_section* output_section,
2765              Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2766   {
2767     this->copy_relocs_.copy_reloc(symtab, layout,
2768                                   symtab->get_sized_symbol<32>(sym),
2769                                   object, shndx, output_section, reloc,
2770                                   this->rel_dyn_section(layout));
2771   }
2772
2773   // Whether two EABI versions are compatible.
2774   static bool
2775   are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2776
2777   // Merge processor-specific flags from input object and those in the ELF
2778   // header of the output.
2779   void
2780   merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2781
2782   // Get the secondary compatible architecture.
2783   static int
2784   get_secondary_compatible_arch(const Attributes_section_data*);
2785
2786   // Set the secondary compatible architecture.
2787   static void
2788   set_secondary_compatible_arch(Attributes_section_data*, int);
2789
2790   static int
2791   tag_cpu_arch_combine(const char*, int, int*, int, int);
2792
2793   // Helper to print AEABI enum tag value.
2794   static std::string
2795   aeabi_enum_name(unsigned int);
2796
2797   // Return string value for TAG_CPU_name.
2798   static std::string
2799   tag_cpu_name_value(unsigned int);
2800
2801   // Query attributes object to see if integer divide instructions may be
2802   // present in an object.
2803   static bool
2804   attributes_accept_div(int arch, int profile,
2805                         const Object_attribute* div_attr);
2806
2807   // Query attributes object to see if integer divide instructions are
2808   // forbidden to be in the object.  This is not the inverse of
2809   // attributes_accept_div.
2810   static bool
2811   attributes_forbid_div(const Object_attribute* div_attr);
2812
2813   // Merge object attributes from input object and those in the output.
2814   void
2815   merge_object_attributes(const char*, const Attributes_section_data*);
2816
2817   // Helper to get an AEABI object attribute
2818   Object_attribute*
2819   get_aeabi_object_attribute(int tag) const
2820   {
2821     Attributes_section_data* pasd = this->attributes_section_data_;
2822     gold_assert(pasd != NULL);
2823     Object_attribute* attr =
2824       pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2825     gold_assert(attr != NULL);
2826     return attr;
2827   }
2828
2829   //
2830   // Methods to support stub-generations.
2831   //
2832
2833   // Group input sections for stub generation.
2834   void
2835   group_sections(Layout*, section_size_type, bool, const Task*);
2836
2837   // Scan a relocation for stub generation.
2838   void
2839   scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2840                       const Sized_symbol<32>*, unsigned int,
2841                       const Symbol_value<32>*,
2842                       elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2843
2844   // Scan a relocation section for stub.
2845   template<int sh_type>
2846   void
2847   scan_reloc_section_for_stubs(
2848       const Relocate_info<32, big_endian>* relinfo,
2849       const unsigned char* prelocs,
2850       size_t reloc_count,
2851       Output_section* output_section,
2852       bool needs_special_offset_handling,
2853       const unsigned char* view,
2854       elfcpp::Elf_types<32>::Elf_Addr view_address,
2855       section_size_type);
2856
2857   // Fix .ARM.exidx section coverage.
2858   void
2859   fix_exidx_coverage(Layout*, const Input_objects*,
2860                      Arm_output_section<big_endian>*, Symbol_table*,
2861                      const Task*);
2862
2863   // Functors for STL set.
2864   struct output_section_address_less_than
2865   {
2866     bool
2867     operator()(const Output_section* s1, const Output_section* s2) const
2868     { return s1->address() < s2->address(); }
2869   };
2870
2871   // Information about this specific target which we pass to the
2872   // general Target structure.
2873   static const Target::Target_info arm_info;
2874
2875   // The types of GOT entries needed for this platform.
2876   // These values are exposed to the ABI in an incremental link.
2877   // Do not renumber existing values without changing the version
2878   // number of the .gnu_incremental_inputs section.
2879   enum Got_type
2880   {
2881     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
2882     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
2883     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
2884     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
2885     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
2886   };
2887
2888   typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2889
2890   // Map input section to Arm_input_section.
2891   typedef Unordered_map<Section_id,
2892                         Arm_input_section<big_endian>*,
2893                         Section_id_hash>
2894           Arm_input_section_map;
2895
2896   // Map output addresses to relocs for Cortex-A8 erratum.
2897   typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2898           Cortex_a8_relocs_info;
2899
2900   // The GOT section.
2901   Arm_output_data_got<big_endian>* got_;
2902   // The PLT section.
2903   Output_data_plt_arm<big_endian>* plt_;
2904   // The GOT PLT section.
2905   Output_data_space* got_plt_;
2906   // The dynamic reloc section.
2907   Reloc_section* rel_dyn_;
2908   // Relocs saved to avoid a COPY reloc.
2909   Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2910   // Space for variables copied with a COPY reloc.
2911   Output_data_space* dynbss_;
2912   // Offset of the GOT entry for the TLS module index.
2913   unsigned int got_mod_index_offset_;
2914   // True if the _TLS_MODULE_BASE_ symbol has been defined.
2915   bool tls_base_symbol_defined_;
2916   // Vector of Stub_tables created.
2917   Stub_table_list stub_tables_;
2918   // Stub factory.
2919   const Stub_factory &stub_factory_;
2920   // Whether we force PIC branch veneers.
2921   bool should_force_pic_veneer_;
2922   // Map for locating Arm_input_sections.
2923   Arm_input_section_map arm_input_section_map_;
2924   // Attributes section data in output.
2925   Attributes_section_data* attributes_section_data_;
2926   // Whether we want to fix code for Cortex-A8 erratum.
2927   bool fix_cortex_a8_;
2928   // Map addresses to relocs for Cortex-A8 erratum.
2929   Cortex_a8_relocs_info cortex_a8_relocs_info_;
2930 };
2931
2932 template<bool big_endian>
2933 const Target::Target_info Target_arm<big_endian>::arm_info =
2934 {
2935   32,                   // size
2936   big_endian,           // is_big_endian
2937   elfcpp::EM_ARM,       // machine_code
2938   false,                // has_make_symbol
2939   false,                // has_resolve
2940   false,                // has_code_fill
2941   true,                 // is_default_stack_executable
2942   false,                // can_icf_inline_merge_sections
2943   '\0',                 // wrap_char
2944   "/usr/lib/libc.so.1", // dynamic_linker
2945   0x8000,               // default_text_segment_address
2946   0x1000,               // abi_pagesize (overridable by -z max-page-size)
2947   0x1000,               // common_pagesize (overridable by -z common-page-size)
2948   false,                // isolate_execinstr
2949   0,                    // rosegment_gap
2950   elfcpp::SHN_UNDEF,    // small_common_shndx
2951   elfcpp::SHN_UNDEF,    // large_common_shndx
2952   0,                    // small_common_section_flags
2953   0,                    // large_common_section_flags
2954   ".ARM.attributes",    // attributes_section
2955   "aeabi",              // attributes_vendor
2956   "_start"              // entry_symbol_name
2957 };
2958
2959 // Arm relocate functions class
2960 //
2961
2962 template<bool big_endian>
2963 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2964 {
2965  public:
2966   typedef enum
2967   {
2968     STATUS_OKAY,        // No error during relocation.
2969     STATUS_OVERFLOW,    // Relocation overflow.
2970     STATUS_BAD_RELOC    // Relocation cannot be applied.
2971   } Status;
2972
2973  private:
2974   typedef Relocate_functions<32, big_endian> Base;
2975   typedef Arm_relocate_functions<big_endian> This;
2976
2977   // Encoding of imm16 argument for movt and movw ARM instructions
2978   // from ARM ARM:
2979   //
2980   //     imm16 := imm4 | imm12
2981   //
2982   //  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
2983   // +-------+---------------+-------+-------+-----------------------+
2984   // |       |               |imm4   |       |imm12                  |
2985   // +-------+---------------+-------+-------+-----------------------+
2986
2987   // Extract the relocation addend from VAL based on the ARM
2988   // instruction encoding described above.
2989   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2990   extract_arm_movw_movt_addend(
2991       typename elfcpp::Swap<32, big_endian>::Valtype val)
2992   {
2993     // According to the Elf ABI for ARM Architecture the immediate
2994     // field is sign-extended to form the addend.
2995     return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff));
2996   }
2997
2998   // Insert X into VAL based on the ARM instruction encoding described
2999   // above.
3000   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3001   insert_val_arm_movw_movt(
3002       typename elfcpp::Swap<32, big_endian>::Valtype val,
3003       typename elfcpp::Swap<32, big_endian>::Valtype x)
3004   {
3005     val &= 0xfff0f000;
3006     val |= x & 0x0fff;
3007     val |= (x & 0xf000) << 4;
3008     return val;
3009   }
3010
3011   // Encoding of imm16 argument for movt and movw Thumb2 instructions
3012   // from ARM ARM:
3013   //
3014   //     imm16 := imm4 | i | imm3 | imm8
3015   //
3016   //  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
3017   // +---------+-+-----------+-------++-+-----+-------+---------------+
3018   // |         |i|           |imm4   || |imm3 |       |imm8           |
3019   // +---------+-+-----------+-------++-+-----+-------+---------------+
3020
3021   // Extract the relocation addend from VAL based on the Thumb2
3022   // instruction encoding described above.
3023   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3024   extract_thumb_movw_movt_addend(
3025       typename elfcpp::Swap<32, big_endian>::Valtype val)
3026   {
3027     // According to the Elf ABI for ARM Architecture the immediate
3028     // field is sign-extended to form the addend.
3029     return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
3030                                    | ((val >> 15) & 0x0800)
3031                                    | ((val >> 4) & 0x0700)
3032                                    | (val & 0x00ff));
3033   }
3034
3035   // Insert X into VAL based on the Thumb2 instruction encoding
3036   // described above.
3037   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3038   insert_val_thumb_movw_movt(
3039       typename elfcpp::Swap<32, big_endian>::Valtype val,
3040       typename elfcpp::Swap<32, big_endian>::Valtype x)
3041   {
3042     val &= 0xfbf08f00;
3043     val |= (x & 0xf000) << 4;
3044     val |= (x & 0x0800) << 15;
3045     val |= (x & 0x0700) << 4;
3046     val |= (x & 0x00ff);
3047     return val;
3048   }
3049
3050   // Calculate the smallest constant Kn for the specified residual.
3051   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3052   static uint32_t
3053   calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3054   {
3055     int32_t msb;
3056
3057     if (residual == 0)
3058       return 0;
3059     // Determine the most significant bit in the residual and
3060     // align the resulting value to a 2-bit boundary.
3061     for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3062       ;
3063     // The desired shift is now (msb - 6), or zero, whichever
3064     // is the greater.
3065     return (((msb - 6) < 0) ? 0 : (msb - 6));
3066   }
3067
3068   // Calculate the final residual for the specified group index.
3069   // If the passed group index is less than zero, the method will return
3070   // the value of the specified residual without any change.
3071   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3072   static typename elfcpp::Swap<32, big_endian>::Valtype
3073   calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3074                     const int group)
3075   {
3076     for (int n = 0; n <= group; n++)
3077       {
3078         // Calculate which part of the value to mask.
3079         uint32_t shift = calc_grp_kn(residual);
3080         // Calculate the residual for the next time around.
3081         residual &= ~(residual & (0xff << shift));
3082       }
3083
3084     return residual;
3085   }
3086
3087   // Calculate the value of Gn for the specified group index.
3088   // We return it in the form of an encoded constant-and-rotation.
3089   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3090   static typename elfcpp::Swap<32, big_endian>::Valtype
3091   calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3092               const int group)
3093   {
3094     typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3095     uint32_t shift = 0;
3096
3097     for (int n = 0; n <= group; n++)
3098       {
3099         // Calculate which part of the value to mask.
3100         shift = calc_grp_kn(residual);
3101         // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3102         gn = residual & (0xff << shift);
3103         // Calculate the residual for the next time around.
3104         residual &= ~gn;
3105       }
3106     // Return Gn in the form of an encoded constant-and-rotation.
3107     return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3108   }
3109
3110  public:
3111   // Handle ARM long branches.
3112   static typename This::Status
3113   arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3114                     unsigned char*, const Sized_symbol<32>*,
3115                     const Arm_relobj<big_endian>*, unsigned int,
3116                     const Symbol_value<32>*, Arm_address, Arm_address, bool);
3117
3118   // Handle THUMB long branches.
3119   static typename This::Status
3120   thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3121                       unsigned char*, const Sized_symbol<32>*,
3122                       const Arm_relobj<big_endian>*, unsigned int,
3123                       const Symbol_value<32>*, Arm_address, Arm_address, bool);
3124
3125
3126   // Return the branch offset of a 32-bit THUMB branch.
3127   static inline int32_t
3128   thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3129   {
3130     // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3131     // involving the J1 and J2 bits.
3132     uint32_t s = (upper_insn & (1U << 10)) >> 10;
3133     uint32_t upper = upper_insn & 0x3ffU;
3134     uint32_t lower = lower_insn & 0x7ffU;
3135     uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3136     uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3137     uint32_t i1 = j1 ^ s ? 0 : 1;
3138     uint32_t i2 = j2 ^ s ? 0 : 1;
3139
3140     return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3141                                    | (upper << 12) | (lower << 1));
3142   }
3143
3144   // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3145   // UPPER_INSN is the original upper instruction of the branch.  Caller is
3146   // responsible for overflow checking and BLX offset adjustment.
3147   static inline uint16_t
3148   thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3149   {
3150     uint32_t s = offset < 0 ? 1 : 0;
3151     uint32_t bits = static_cast<uint32_t>(offset);
3152     return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3153   }
3154
3155   // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3156   // LOWER_INSN is the original lower instruction of the branch.  Caller is
3157   // responsible for overflow checking and BLX offset adjustment.
3158   static inline uint16_t
3159   thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3160   {
3161     uint32_t s = offset < 0 ? 1 : 0;
3162     uint32_t bits = static_cast<uint32_t>(offset);
3163     return ((lower_insn & ~0x2fffU)
3164             | ((((bits >> 23) & 1) ^ !s) << 13)
3165             | ((((bits >> 22) & 1) ^ !s) << 11)
3166             | ((bits >> 1) & 0x7ffU));
3167   }
3168
3169   // Return the branch offset of a 32-bit THUMB conditional branch.
3170   static inline int32_t
3171   thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3172   {
3173     uint32_t s = (upper_insn & 0x0400U) >> 10;
3174     uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3175     uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3176     uint32_t lower = (lower_insn & 0x07ffU);
3177     uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3178
3179     return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3180   }
3181
3182   // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3183   // instruction.  UPPER_INSN is the original upper instruction of the branch.
3184   // Caller is responsible for overflow checking.
3185   static inline uint16_t
3186   thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3187   {
3188     uint32_t s = offset < 0 ? 1 : 0;
3189     uint32_t bits = static_cast<uint32_t>(offset);
3190     return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3191   }
3192
3193   // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3194   // instruction.  LOWER_INSN is the original lower instruction of the branch.
3195   // The caller is responsible for overflow checking.
3196   static inline uint16_t
3197   thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3198   {
3199     uint32_t bits = static_cast<uint32_t>(offset);
3200     uint32_t j2 = (bits & 0x00080000U) >> 19;
3201     uint32_t j1 = (bits & 0x00040000U) >> 18;
3202     uint32_t lo = (bits & 0x00000ffeU) >> 1;
3203
3204     return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3205   }
3206
3207   // R_ARM_ABS8: S + A
3208   static inline typename This::Status
3209   abs8(unsigned char* view,
3210        const Sized_relobj_file<32, big_endian>* object,
3211        const Symbol_value<32>* psymval)
3212   {
3213     typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3214     Valtype* wv = reinterpret_cast<Valtype*>(view);
3215     Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3216     int32_t addend = Bits<8>::sign_extend32(val);
3217     Arm_address x = psymval->value(object, addend);
3218     val = Bits<32>::bit_select32(val, x, 0xffU);
3219     elfcpp::Swap<8, big_endian>::writeval(wv, val);
3220
3221     // R_ARM_ABS8 permits signed or unsigned results.
3222     return (Bits<8>::has_signed_unsigned_overflow32(x)
3223             ? This::STATUS_OVERFLOW
3224             : This::STATUS_OKAY);
3225   }
3226
3227   // R_ARM_THM_ABS5: S + A
3228   static inline typename This::Status
3229   thm_abs5(unsigned char* view,
3230        const Sized_relobj_file<32, big_endian>* object,
3231        const Symbol_value<32>* psymval)
3232   {
3233     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3234     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3235     Valtype* wv = reinterpret_cast<Valtype*>(view);
3236     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3237     Reltype addend = (val & 0x7e0U) >> 6;
3238     Reltype x = psymval->value(object, addend);
3239     val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3240     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3241     return (Bits<5>::has_overflow32(x)
3242             ? This::STATUS_OVERFLOW
3243             : This::STATUS_OKAY);
3244   }
3245
3246   // R_ARM_ABS12: S + A
3247   static inline typename This::Status
3248   abs12(unsigned char* view,
3249         const Sized_relobj_file<32, big_endian>* object,
3250         const Symbol_value<32>* psymval)
3251   {
3252     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3253     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3254     Valtype* wv = reinterpret_cast<Valtype*>(view);
3255     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3256     Reltype addend = val & 0x0fffU;
3257     Reltype x = psymval->value(object, addend);
3258     val = Bits<32>::bit_select32(val, x, 0x0fffU);
3259     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3260     return (Bits<12>::has_overflow32(x)
3261             ? This::STATUS_OVERFLOW
3262             : This::STATUS_OKAY);
3263   }
3264
3265   // R_ARM_ABS16: S + A
3266   static inline typename This::Status
3267   abs16(unsigned char* view,
3268         const Sized_relobj_file<32, big_endian>* object,
3269         const Symbol_value<32>* psymval)
3270   {
3271     typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
3272     Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view);
3273     int32_t addend = Bits<16>::sign_extend32(val);
3274     Arm_address x = psymval->value(object, addend);
3275     val = Bits<32>::bit_select32(val, x, 0xffffU);
3276     elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val);
3277
3278     // R_ARM_ABS16 permits signed or unsigned results.
3279     return (Bits<16>::has_signed_unsigned_overflow32(x)
3280             ? This::STATUS_OVERFLOW
3281             : This::STATUS_OKAY);
3282   }
3283
3284   // R_ARM_ABS32: (S + A) | T
3285   static inline typename This::Status
3286   abs32(unsigned char* view,
3287         const Sized_relobj_file<32, big_endian>* object,
3288         const Symbol_value<32>* psymval,
3289         Arm_address thumb_bit)
3290   {
3291     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3292     Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3293     Valtype x = psymval->value(object, addend) | thumb_bit;
3294     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3295     return This::STATUS_OKAY;
3296   }
3297
3298   // R_ARM_REL32: (S + A) | T - P
3299   static inline typename This::Status
3300   rel32(unsigned char* view,
3301         const Sized_relobj_file<32, big_endian>* object,
3302         const Symbol_value<32>* psymval,
3303         Arm_address address,
3304         Arm_address thumb_bit)
3305   {
3306     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3307     Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3308     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3309     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3310     return This::STATUS_OKAY;
3311   }
3312
3313   // R_ARM_THM_JUMP24: (S + A) | T - P
3314   static typename This::Status
3315   thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3316              const Symbol_value<32>* psymval, Arm_address address,
3317              Arm_address thumb_bit);
3318
3319   // R_ARM_THM_JUMP6: S + A â€“ P
3320   static inline typename This::Status
3321   thm_jump6(unsigned char* view,
3322             const Sized_relobj_file<32, big_endian>* object,
3323             const Symbol_value<32>* psymval,
3324             Arm_address address)
3325   {
3326     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3327     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3328     Valtype* wv = reinterpret_cast<Valtype*>(view);
3329     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3330     // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3331     Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3332     Reltype x = (psymval->value(object, addend) - address);
3333     val = (val & 0xfd07) | ((x  & 0x0040) << 3) | ((val & 0x003e) << 2);
3334     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3335     // CZB does only forward jumps.
3336     return ((x > 0x007e)
3337             ? This::STATUS_OVERFLOW
3338             : This::STATUS_OKAY);
3339   }
3340
3341   // R_ARM_THM_JUMP8: S + A â€“ P
3342   static inline typename This::Status
3343   thm_jump8(unsigned char* view,
3344             const Sized_relobj_file<32, big_endian>* object,
3345             const Symbol_value<32>* psymval,
3346             Arm_address address)
3347   {
3348     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3349     Valtype* wv = reinterpret_cast<Valtype*>(view);
3350     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3351     int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1);
3352     int32_t x = (psymval->value(object, addend) - address);
3353     elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00)
3354                                                 | ((x & 0x01fe) >> 1)));
3355     // We do a 9-bit overflow check because x is right-shifted by 1 bit.
3356     return (Bits<9>::has_overflow32(x)
3357             ? This::STATUS_OVERFLOW
3358             : This::STATUS_OKAY);
3359   }
3360
3361   // R_ARM_THM_JUMP11: S + A â€“ P
3362   static inline typename This::Status
3363   thm_jump11(unsigned char* view,
3364             const Sized_relobj_file<32, big_endian>* object,
3365             const Symbol_value<32>* psymval,
3366             Arm_address address)
3367   {
3368     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3369     Valtype* wv = reinterpret_cast<Valtype*>(view);
3370     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3371     int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1);
3372     int32_t x = (psymval->value(object, addend) - address);
3373     elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800)
3374                                                 | ((x & 0x0ffe) >> 1)));
3375     // We do a 12-bit overflow check because x is right-shifted by 1 bit.
3376     return (Bits<12>::has_overflow32(x)
3377             ? This::STATUS_OVERFLOW
3378             : This::STATUS_OKAY);
3379   }
3380
3381   // R_ARM_BASE_PREL: B(S) + A - P
3382   static inline typename This::Status
3383   base_prel(unsigned char* view,
3384             Arm_address origin,
3385             Arm_address address)
3386   {
3387     Base::rel32(view, origin - address);
3388     return STATUS_OKAY;
3389   }
3390
3391   // R_ARM_BASE_ABS: B(S) + A
3392   static inline typename This::Status
3393   base_abs(unsigned char* view,
3394            Arm_address origin)
3395   {
3396     Base::rel32(view, origin);
3397     return STATUS_OKAY;
3398   }
3399
3400   // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3401   static inline typename This::Status
3402   got_brel(unsigned char* view,
3403            typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3404   {
3405     Base::rel32(view, got_offset);
3406     return This::STATUS_OKAY;
3407   }
3408
3409   // R_ARM_GOT_PREL: GOT(S) + A - P
3410   static inline typename This::Status
3411   got_prel(unsigned char* view,
3412            Arm_address got_entry,
3413            Arm_address address)
3414   {
3415     Base::rel32(view, got_entry - address);
3416     return This::STATUS_OKAY;
3417   }
3418
3419   // R_ARM_PREL: (S + A) | T - P
3420   static inline typename This::Status
3421   prel31(unsigned char* view,
3422          const Sized_relobj_file<32, big_endian>* object,
3423          const Symbol_value<32>* psymval,
3424          Arm_address address,
3425          Arm_address thumb_bit)
3426   {
3427     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3428     Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3429     Valtype addend = Bits<31>::sign_extend32(val);
3430     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3431     val = Bits<32>::bit_select32(val, x, 0x7fffffffU);
3432     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val);
3433     return (Bits<31>::has_overflow32(x)
3434             ? This::STATUS_OVERFLOW
3435             : This::STATUS_OKAY);
3436   }
3437
3438   // R_ARM_MOVW_ABS_NC: (S + A) | T     (relative address base is )
3439   // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3440   // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3441   // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3442   static inline typename This::Status
3443   movw(unsigned char* view,
3444        const Sized_relobj_file<32, big_endian>* object,
3445        const Symbol_value<32>* psymval,
3446        Arm_address relative_address_base,
3447        Arm_address thumb_bit,
3448        bool check_overflow)
3449   {
3450     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3451     Valtype* wv = reinterpret_cast<Valtype*>(view);
3452     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3453     Valtype addend = This::extract_arm_movw_movt_addend(val);
3454     Valtype x = ((psymval->value(object, addend) | thumb_bit)
3455                  - relative_address_base);
3456     val = This::insert_val_arm_movw_movt(val, x);
3457     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3458     return ((check_overflow && Bits<16>::has_overflow32(x))
3459             ? This::STATUS_OVERFLOW
3460             : This::STATUS_OKAY);
3461   }
3462
3463   // R_ARM_MOVT_ABS: S + A      (relative address base is 0)
3464   // R_ARM_MOVT_PREL: S + A - P
3465   // R_ARM_MOVT_BREL: S + A - B(S)
3466   static inline typename This::Status
3467   movt(unsigned char* view,
3468        const Sized_relobj_file<32, big_endian>* object,
3469        const Symbol_value<32>* psymval,
3470        Arm_address relative_address_base)
3471   {
3472     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3473     Valtype* wv = reinterpret_cast<Valtype*>(view);
3474     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3475     Valtype addend = This::extract_arm_movw_movt_addend(val);
3476     Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3477     val = This::insert_val_arm_movw_movt(val, x);
3478     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3479     // FIXME: IHI0044D says that we should check for overflow.
3480     return This::STATUS_OKAY;
3481   }
3482
3483   // R_ARM_THM_MOVW_ABS_NC: S + A | T           (relative_address_base is 0)
3484   // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3485   // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3486   // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3487   static inline typename This::Status
3488   thm_movw(unsigned char* view,
3489            const Sized_relobj_file<32, big_endian>* object,
3490            const Symbol_value<32>* psymval,
3491            Arm_address relative_address_base,
3492            Arm_address thumb_bit,
3493            bool check_overflow)
3494   {
3495     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3496     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3497     Valtype* wv = reinterpret_cast<Valtype*>(view);
3498     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3499                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3500     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3501     Reltype x =
3502       (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3503     val = This::insert_val_thumb_movw_movt(val, x);
3504     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3505     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3506     return ((check_overflow && Bits<16>::has_overflow32(x))
3507             ? This::STATUS_OVERFLOW
3508             : This::STATUS_OKAY);
3509   }
3510
3511   // R_ARM_THM_MOVT_ABS: S + A          (relative address base is 0)
3512   // R_ARM_THM_MOVT_PREL: S + A - P
3513   // R_ARM_THM_MOVT_BREL: S + A - B(S)
3514   static inline typename This::Status
3515   thm_movt(unsigned char* view,
3516            const Sized_relobj_file<32, big_endian>* object,
3517            const Symbol_value<32>* psymval,
3518            Arm_address relative_address_base)
3519   {
3520     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3521     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3522     Valtype* wv = reinterpret_cast<Valtype*>(view);
3523     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3524                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3525     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3526     Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3527     val = This::insert_val_thumb_movw_movt(val, x);
3528     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3529     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3530     return This::STATUS_OKAY;
3531   }
3532
3533   // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3534   static inline typename This::Status
3535   thm_alu11(unsigned char* view,
3536             const Sized_relobj_file<32, big_endian>* object,
3537             const Symbol_value<32>* psymval,
3538             Arm_address address,
3539             Arm_address thumb_bit)
3540   {
3541     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3542     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3543     Valtype* wv = reinterpret_cast<Valtype*>(view);
3544     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3545                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3546
3547     //        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
3548     // -----------------------------------------------------------------------
3549     // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd     |imm8
3550     // ADDW   1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd     |imm8
3551     // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd     |imm8
3552     // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd     |imm8
3553     // SUBW   1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd     |imm8
3554     // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd     |imm8
3555
3556     // Determine a sign for the addend.
3557     const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3558                       || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3559     // Thumb2 addend encoding:
3560     // imm12 := i | imm3 | imm8
3561     int32_t addend = (insn & 0xff)
3562                      | ((insn & 0x00007000) >> 4)
3563                      | ((insn & 0x04000000) >> 15);
3564     // Apply a sign to the added.
3565     addend *= sign;
3566
3567     int32_t x = (psymval->value(object, addend) | thumb_bit)
3568                 - (address & 0xfffffffc);
3569     Reltype val = abs(x);
3570     // Mask out the value and a distinct part of the ADD/SUB opcode
3571     // (bits 7:5 of opword).
3572     insn = (insn & 0xfb0f8f00)
3573            | (val & 0xff)
3574            | ((val & 0x700) << 4)
3575            | ((val & 0x800) << 15);
3576     // Set the opcode according to whether the value to go in the
3577     // place is negative.
3578     if (x < 0)
3579       insn |= 0x00a00000;
3580
3581     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3582     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3583     return ((val > 0xfff) ?
3584             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3585   }
3586
3587   // R_ARM_THM_PC8: S + A - Pa (Thumb)
3588   static inline typename This::Status
3589   thm_pc8(unsigned char* view,
3590           const Sized_relobj_file<32, big_endian>* object,
3591           const Symbol_value<32>* psymval,
3592           Arm_address address)
3593   {
3594     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3595     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3596     Valtype* wv = reinterpret_cast<Valtype*>(view);
3597     Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3598     Reltype addend = ((insn & 0x00ff) << 2);
3599     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3600     Reltype val = abs(x);
3601     insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3602
3603     elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3604     return ((val > 0x03fc)
3605             ? This::STATUS_OVERFLOW
3606             : This::STATUS_OKAY);
3607   }
3608
3609   // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3610   static inline typename This::Status
3611   thm_pc12(unsigned char* view,
3612            const Sized_relobj_file<32, big_endian>* object,
3613            const Symbol_value<32>* psymval,
3614            Arm_address address)
3615   {
3616     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3617     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3618     Valtype* wv = reinterpret_cast<Valtype*>(view);
3619     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3620                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3621     // Determine a sign for the addend (positive if the U bit is 1).
3622     const int sign = (insn & 0x00800000) ? 1 : -1;
3623     int32_t addend = (insn & 0xfff);
3624     // Apply a sign to the added.
3625     addend *= sign;
3626
3627     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3628     Reltype val = abs(x);
3629     // Mask out and apply the value and the U bit.
3630     insn = (insn & 0xff7ff000) | (val & 0xfff);
3631     // Set the U bit according to whether the value to go in the
3632     // place is positive.
3633     if (x >= 0)
3634       insn |= 0x00800000;
3635
3636     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3637     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3638     return ((val > 0xfff) ?
3639             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3640   }
3641
3642   // R_ARM_V4BX
3643   static inline typename This::Status
3644   v4bx(const Relocate_info<32, big_endian>* relinfo,
3645        unsigned char* view,
3646        const Arm_relobj<big_endian>* object,
3647        const Arm_address address,
3648        const bool is_interworking)
3649   {
3650
3651     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3652     Valtype* wv = reinterpret_cast<Valtype*>(view);
3653     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3654
3655     // Ensure that we have a BX instruction.
3656     gold_assert((val & 0x0ffffff0) == 0x012fff10);
3657     const uint32_t reg = (val & 0xf);
3658     if (is_interworking && reg != 0xf)
3659       {
3660         Stub_table<big_endian>* stub_table =
3661             object->stub_table(relinfo->data_shndx);
3662         gold_assert(stub_table != NULL);
3663
3664         Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3665         gold_assert(stub != NULL);
3666
3667         int32_t veneer_address =
3668             stub_table->address() + stub->offset() - 8 - address;
3669         gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3670                     && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3671         // Replace with a branch to veneer (B <addr>)
3672         val = (val & 0xf0000000) | 0x0a000000
3673               | ((veneer_address >> 2) & 0x00ffffff);
3674       }
3675     else
3676       {
3677         // Preserve Rm (lowest four bits) and the condition code
3678         // (highest four bits). Other bits encode MOV PC,Rm.
3679         val = (val & 0xf000000f) | 0x01a0f000;
3680       }
3681     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3682     return This::STATUS_OKAY;
3683   }
3684
3685   // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3686   // R_ARM_ALU_PC_G0:    ((S + A) | T) - P
3687   // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3688   // R_ARM_ALU_PC_G1:    ((S + A) | T) - P
3689   // R_ARM_ALU_PC_G2:    ((S + A) | T) - P
3690   // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3691   // R_ARM_ALU_SB_G0:    ((S + A) | T) - B(S)
3692   // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3693   // R_ARM_ALU_SB_G1:    ((S + A) | T) - B(S)
3694   // R_ARM_ALU_SB_G2:    ((S + A) | T) - B(S)
3695   static inline typename This::Status
3696   arm_grp_alu(unsigned char* view,
3697         const Sized_relobj_file<32, big_endian>* object,
3698         const Symbol_value<32>* psymval,
3699         const int group,
3700         Arm_address address,
3701         Arm_address thumb_bit,
3702         bool check_overflow)
3703   {
3704     gold_assert(group >= 0 && group < 3);
3705     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3706     Valtype* wv = reinterpret_cast<Valtype*>(view);
3707     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3708
3709     // ALU group relocations are allowed only for the ADD/SUB instructions.
3710     // (0x00800000 - ADD, 0x00400000 - SUB)
3711     const Valtype opcode = insn & 0x01e00000;
3712     if (opcode != 0x00800000 && opcode != 0x00400000)
3713       return This::STATUS_BAD_RELOC;
3714
3715     // Determine a sign for the addend.
3716     const int sign = (opcode == 0x00800000) ? 1 : -1;
3717     // shifter = rotate_imm * 2
3718     const uint32_t shifter = (insn & 0xf00) >> 7;
3719     // Initial addend value.
3720     int32_t addend = insn & 0xff;
3721     // Rotate addend right by shifter.
3722     addend = (addend >> shifter) | (addend << (32 - shifter));
3723     // Apply a sign to the added.
3724     addend *= sign;
3725
3726     int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3727     Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3728     // Check for overflow if required
3729     if (check_overflow
3730         && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3731       return This::STATUS_OVERFLOW;
3732
3733     // Mask out the value and the ADD/SUB part of the opcode; take care
3734     // not to destroy the S bit.
3735     insn &= 0xff1ff000;
3736     // Set the opcode according to whether the value to go in the
3737     // place is negative.
3738     insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3739     // Encode the offset (encoded Gn).
3740     insn |= gn;
3741
3742     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3743     return This::STATUS_OKAY;
3744   }
3745
3746   // R_ARM_LDR_PC_G0: S + A - P
3747   // R_ARM_LDR_PC_G1: S + A - P
3748   // R_ARM_LDR_PC_G2: S + A - P
3749   // R_ARM_LDR_SB_G0: S + A - B(S)
3750   // R_ARM_LDR_SB_G1: S + A - B(S)
3751   // R_ARM_LDR_SB_G2: S + A - B(S)
3752   static inline typename This::Status
3753   arm_grp_ldr(unsigned char* view,
3754         const Sized_relobj_file<32, big_endian>* object,
3755         const Symbol_value<32>* psymval,
3756         const int group,
3757         Arm_address address)
3758   {
3759     gold_assert(group >= 0 && group < 3);
3760     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3761     Valtype* wv = reinterpret_cast<Valtype*>(view);
3762     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3763
3764     const int sign = (insn & 0x00800000) ? 1 : -1;
3765     int32_t addend = (insn & 0xfff) * sign;
3766     int32_t x = (psymval->value(object, addend) - address);
3767     // Calculate the relevant G(n-1) value to obtain this stage residual.
3768     Valtype residual =
3769         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3770     if (residual >= 0x1000)
3771       return This::STATUS_OVERFLOW;
3772
3773     // Mask out the value and U bit.
3774     insn &= 0xff7ff000;
3775     // Set the U bit for non-negative values.
3776     if (x >= 0)
3777       insn |= 0x00800000;
3778     insn |= residual;
3779
3780     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3781     return This::STATUS_OKAY;
3782   }
3783
3784   // R_ARM_LDRS_PC_G0: S + A - P
3785   // R_ARM_LDRS_PC_G1: S + A - P
3786   // R_ARM_LDRS_PC_G2: S + A - P
3787   // R_ARM_LDRS_SB_G0: S + A - B(S)
3788   // R_ARM_LDRS_SB_G1: S + A - B(S)
3789   // R_ARM_LDRS_SB_G2: S + A - B(S)
3790   static inline typename This::Status
3791   arm_grp_ldrs(unsigned char* view,
3792         const Sized_relobj_file<32, big_endian>* object,
3793         const Symbol_value<32>* psymval,
3794         const int group,
3795         Arm_address address)
3796   {
3797     gold_assert(group >= 0 && group < 3);
3798     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3799     Valtype* wv = reinterpret_cast<Valtype*>(view);
3800     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3801
3802     const int sign = (insn & 0x00800000) ? 1 : -1;
3803     int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3804     int32_t x = (psymval->value(object, addend) - address);
3805     // Calculate the relevant G(n-1) value to obtain this stage residual.
3806     Valtype residual =
3807         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3808    if (residual >= 0x100)
3809       return This::STATUS_OVERFLOW;
3810
3811     // Mask out the value and U bit.
3812     insn &= 0xff7ff0f0;
3813     // Set the U bit for non-negative values.
3814     if (x >= 0)
3815       insn |= 0x00800000;
3816     insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3817
3818     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3819     return This::STATUS_OKAY;
3820   }
3821
3822   // R_ARM_LDC_PC_G0: S + A - P
3823   // R_ARM_LDC_PC_G1: S + A - P
3824   // R_ARM_LDC_PC_G2: S + A - P
3825   // R_ARM_LDC_SB_G0: S + A - B(S)
3826   // R_ARM_LDC_SB_G1: S + A - B(S)
3827   // R_ARM_LDC_SB_G2: S + A - B(S)
3828   static inline typename This::Status
3829   arm_grp_ldc(unsigned char* view,
3830       const Sized_relobj_file<32, big_endian>* object,
3831       const Symbol_value<32>* psymval,
3832       const int group,
3833       Arm_address address)
3834   {
3835     gold_assert(group >= 0 && group < 3);
3836     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3837     Valtype* wv = reinterpret_cast<Valtype*>(view);
3838     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3839
3840     const int sign = (insn & 0x00800000) ? 1 : -1;
3841     int32_t addend = ((insn & 0xff) << 2) * sign;
3842     int32_t x = (psymval->value(object, addend) - address);
3843     // Calculate the relevant G(n-1) value to obtain this stage residual.
3844     Valtype residual =
3845       Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3846     if ((residual & 0x3) != 0 || residual >= 0x400)
3847       return This::STATUS_OVERFLOW;
3848
3849     // Mask out the value and U bit.
3850     insn &= 0xff7fff00;
3851     // Set the U bit for non-negative values.
3852     if (x >= 0)
3853       insn |= 0x00800000;
3854     insn |= (residual >> 2);
3855
3856     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3857     return This::STATUS_OKAY;
3858   }
3859 };
3860
3861 // Relocate ARM long branches.  This handles relocation types
3862 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3863 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3864 // undefined and we do not use PLT in this relocation.  In such a case,
3865 // the branch is converted into an NOP.
3866
3867 template<bool big_endian>
3868 typename Arm_relocate_functions<big_endian>::Status
3869 Arm_relocate_functions<big_endian>::arm_branch_common(
3870     unsigned int r_type,
3871     const Relocate_info<32, big_endian>* relinfo,
3872     unsigned char* view,
3873     const Sized_symbol<32>* gsym,
3874     const Arm_relobj<big_endian>* object,
3875     unsigned int r_sym,
3876     const Symbol_value<32>* psymval,
3877     Arm_address address,
3878     Arm_address thumb_bit,
3879     bool is_weakly_undefined_without_plt)
3880 {
3881   typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3882   Valtype* wv = reinterpret_cast<Valtype*>(view);
3883   Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3884
3885   bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3886                     && ((val & 0x0f000000UL) == 0x0a000000UL);
3887   bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3888   bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3889                           && ((val & 0x0f000000UL) == 0x0b000000UL);
3890   bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3891   bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3892
3893   // Check that the instruction is valid.
3894   if (r_type == elfcpp::R_ARM_CALL)
3895     {
3896       if (!insn_is_uncond_bl && !insn_is_blx)
3897         return This::STATUS_BAD_RELOC;
3898     }
3899   else if (r_type == elfcpp::R_ARM_JUMP24)
3900     {
3901       if (!insn_is_b && !insn_is_cond_bl)
3902         return This::STATUS_BAD_RELOC;
3903     }
3904   else if (r_type == elfcpp::R_ARM_PLT32)
3905     {
3906       if (!insn_is_any_branch)
3907         return This::STATUS_BAD_RELOC;
3908     }
3909   else if (r_type == elfcpp::R_ARM_XPC25)
3910     {
3911       // FIXME: AAELF document IH0044C does not say much about it other
3912       // than it being obsolete.
3913       if (!insn_is_any_branch)
3914         return This::STATUS_BAD_RELOC;
3915     }
3916   else
3917     gold_unreachable();
3918
3919   // A branch to an undefined weak symbol is turned into a jump to
3920   // the next instruction unless a PLT entry will be created.
3921   // Do the same for local undefined symbols.
3922   // The jump to the next instruction is optimized as a NOP depending
3923   // on the architecture.
3924   const Target_arm<big_endian>* arm_target =
3925     Target_arm<big_endian>::default_target();
3926   if (is_weakly_undefined_without_plt)
3927     {
3928       gold_assert(!parameters->options().relocatable());
3929       Valtype cond = val & 0xf0000000U;
3930       if (arm_target->may_use_arm_nop())
3931         val = cond | 0x0320f000;
3932       else
3933         val = cond | 0x01a00000;        // Using pre-UAL nop: mov r0, r0.
3934       elfcpp::Swap<32, big_endian>::writeval(wv, val);
3935       return This::STATUS_OKAY;
3936     }
3937
3938   Valtype addend = Bits<26>::sign_extend32(val << 2);
3939   Valtype branch_target = psymval->value(object, addend);
3940   int32_t branch_offset = branch_target - address;
3941
3942   // We need a stub if the branch offset is too large or if we need
3943   // to switch mode.
3944   bool may_use_blx = arm_target->may_use_v5t_interworking();
3945   Reloc_stub* stub = NULL;
3946
3947   if (!parameters->options().relocatable()
3948       && (Bits<26>::has_overflow32(branch_offset)
3949           || ((thumb_bit != 0)
3950               && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3951     {
3952       Valtype unadjusted_branch_target = psymval->value(object, 0);
3953
3954       Stub_type stub_type =
3955         Reloc_stub::stub_type_for_reloc(r_type, address,
3956                                         unadjusted_branch_target,
3957                                         (thumb_bit != 0));
3958       if (stub_type != arm_stub_none)
3959         {
3960           Stub_table<big_endian>* stub_table =
3961             object->stub_table(relinfo->data_shndx);
3962           gold_assert(stub_table != NULL);
3963
3964           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3965           stub = stub_table->find_reloc_stub(stub_key);
3966           gold_assert(stub != NULL);
3967           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3968           branch_target = stub_table->address() + stub->offset() + addend;
3969           branch_offset = branch_target - address;
3970           gold_assert(!Bits<26>::has_overflow32(branch_offset));
3971         }
3972     }
3973
3974   // At this point, if we still need to switch mode, the instruction
3975   // must either be a BLX or a BL that can be converted to a BLX.
3976   if (thumb_bit != 0)
3977     {
3978       // Turn BL to BLX.
3979       gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3980       val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3981     }
3982
3983   val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL);
3984   elfcpp::Swap<32, big_endian>::writeval(wv, val);
3985   return (Bits<26>::has_overflow32(branch_offset)
3986           ? This::STATUS_OVERFLOW
3987           : This::STATUS_OKAY);
3988 }
3989
3990 // Relocate THUMB long branches.  This handles relocation types
3991 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3992 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3993 // undefined and we do not use PLT in this relocation.  In such a case,
3994 // the branch is converted into an NOP.
3995
3996 template<bool big_endian>
3997 typename Arm_relocate_functions<big_endian>::Status
3998 Arm_relocate_functions<big_endian>::thumb_branch_common(
3999     unsigned int r_type,
4000     const Relocate_info<32, big_endian>* relinfo,
4001     unsigned char* view,
4002     const Sized_symbol<32>* gsym,
4003     const Arm_relobj<big_endian>* object,
4004     unsigned int r_sym,
4005     const Symbol_value<32>* psymval,
4006     Arm_address address,
4007     Arm_address thumb_bit,
4008     bool is_weakly_undefined_without_plt)
4009 {
4010   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4011   Valtype* wv = reinterpret_cast<Valtype*>(view);
4012   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4013   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4014
4015   // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
4016   // into account.
4017   bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
4018   bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
4019
4020   // Check that the instruction is valid.
4021   if (r_type == elfcpp::R_ARM_THM_CALL)
4022     {
4023       if (!is_bl_insn && !is_blx_insn)
4024         return This::STATUS_BAD_RELOC;
4025     }
4026   else if (r_type == elfcpp::R_ARM_THM_JUMP24)
4027     {
4028       // This cannot be a BLX.
4029       if (!is_bl_insn)
4030         return This::STATUS_BAD_RELOC;
4031     }
4032   else if (r_type == elfcpp::R_ARM_THM_XPC22)
4033     {
4034       // Check for Thumb to Thumb call.
4035       if (!is_blx_insn)
4036         return This::STATUS_BAD_RELOC;
4037       if (thumb_bit != 0)
4038         {
4039           gold_warning(_("%s: Thumb BLX instruction targets "
4040                          "thumb function '%s'."),
4041                          object->name().c_str(),
4042                          (gsym ? gsym->name() : "(local)"));
4043           // Convert BLX to BL.
4044           lower_insn |= 0x1000U;
4045         }
4046     }
4047   else
4048     gold_unreachable();
4049
4050   // A branch to an undefined weak symbol is turned into a jump to
4051   // the next instruction unless a PLT entry will be created.
4052   // The jump to the next instruction is optimized as a NOP.W for
4053   // Thumb-2 enabled architectures.
4054   const Target_arm<big_endian>* arm_target =
4055     Target_arm<big_endian>::default_target();
4056   if (is_weakly_undefined_without_plt)
4057     {
4058       gold_assert(!parameters->options().relocatable());
4059       if (arm_target->may_use_thumb2_nop())
4060         {
4061           elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4062           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4063         }
4064       else
4065         {
4066           elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4067           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4068         }
4069       return This::STATUS_OKAY;
4070     }
4071
4072   int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4073   Arm_address branch_target = psymval->value(object, addend);
4074
4075   // For BLX, bit 1 of target address comes from bit 1 of base address.
4076   bool may_use_blx = arm_target->may_use_v5t_interworking();
4077   if (thumb_bit == 0 && may_use_blx)
4078     branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4079
4080   int32_t branch_offset = branch_target - address;
4081
4082   // We need a stub if the branch offset is too large or if we need
4083   // to switch mode.
4084   bool thumb2 = arm_target->using_thumb2();
4085   if (!parameters->options().relocatable()
4086       && ((!thumb2 && Bits<23>::has_overflow32(branch_offset))
4087           || (thumb2 && Bits<25>::has_overflow32(branch_offset))
4088           || ((thumb_bit == 0)
4089               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4090                   || r_type == elfcpp::R_ARM_THM_JUMP24))))
4091     {
4092       Arm_address unadjusted_branch_target = psymval->value(object, 0);
4093
4094       Stub_type stub_type =
4095         Reloc_stub::stub_type_for_reloc(r_type, address,
4096                                         unadjusted_branch_target,
4097                                         (thumb_bit != 0));
4098
4099       if (stub_type != arm_stub_none)
4100         {
4101           Stub_table<big_endian>* stub_table =
4102             object->stub_table(relinfo->data_shndx);
4103           gold_assert(stub_table != NULL);
4104
4105           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4106           Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4107           gold_assert(stub != NULL);
4108           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4109           branch_target = stub_table->address() + stub->offset() + addend;
4110           if (thumb_bit == 0 && may_use_blx)
4111             branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4112           branch_offset = branch_target - address;
4113         }
4114     }
4115
4116   // At this point, if we still need to switch mode, the instruction
4117   // must either be a BLX or a BL that can be converted to a BLX.
4118   if (thumb_bit == 0)
4119     {
4120       gold_assert(may_use_blx
4121                   && (r_type == elfcpp::R_ARM_THM_CALL
4122                       || r_type == elfcpp::R_ARM_THM_XPC22));
4123       // Make sure this is a BLX.
4124       lower_insn &= ~0x1000U;
4125     }
4126   else
4127     {
4128       // Make sure this is a BL.
4129       lower_insn |= 0x1000U;
4130     }
4131
4132   // For a BLX instruction, make sure that the relocation is rounded up
4133   // to a word boundary.  This follows the semantics of the instruction
4134   // which specifies that bit 1 of the target address will come from bit
4135   // 1 of the base address.
4136   if ((lower_insn & 0x5000U) == 0x4000U)
4137     gold_assert((branch_offset & 3) == 0);
4138
4139   // Put BRANCH_OFFSET back into the insn.  Assumes two's complement.
4140   // We use the Thumb-2 encoding, which is safe even if dealing with
4141   // a Thumb-1 instruction by virtue of our overflow check above.  */
4142   upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4143   lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4144
4145   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4146   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4147
4148   gold_assert(!Bits<25>::has_overflow32(branch_offset));
4149
4150   return ((thumb2
4151            ? Bits<25>::has_overflow32(branch_offset)
4152            : Bits<23>::has_overflow32(branch_offset))
4153           ? This::STATUS_OVERFLOW
4154           : This::STATUS_OKAY);
4155 }
4156
4157 // Relocate THUMB-2 long conditional branches.
4158 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
4159 // undefined and we do not use PLT in this relocation.  In such a case,
4160 // the branch is converted into an NOP.
4161
4162 template<bool big_endian>
4163 typename Arm_relocate_functions<big_endian>::Status
4164 Arm_relocate_functions<big_endian>::thm_jump19(
4165     unsigned char* view,
4166     const Arm_relobj<big_endian>* object,
4167     const Symbol_value<32>* psymval,
4168     Arm_address address,
4169     Arm_address thumb_bit)
4170 {
4171   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4172   Valtype* wv = reinterpret_cast<Valtype*>(view);
4173   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4174   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4175   int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4176
4177   Arm_address branch_target = psymval->value(object, addend);
4178   int32_t branch_offset = branch_target - address;
4179
4180   // ??? Should handle interworking?  GCC might someday try to
4181   // use this for tail calls.
4182   // FIXME: We do support thumb entry to PLT yet.
4183   if (thumb_bit == 0)
4184     {
4185       gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4186       return This::STATUS_BAD_RELOC;
4187     }
4188
4189   // Put RELOCATION back into the insn.
4190   upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4191   lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4192
4193   // Put the relocated value back in the object file:
4194   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4195   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4196
4197   return (Bits<21>::has_overflow32(branch_offset)
4198           ? This::STATUS_OVERFLOW
4199           : This::STATUS_OKAY);
4200 }
4201
4202 // Get the GOT section, creating it if necessary.
4203
4204 template<bool big_endian>
4205 Arm_output_data_got<big_endian>*
4206 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4207 {
4208   if (this->got_ == NULL)
4209     {
4210       gold_assert(symtab != NULL && layout != NULL);
4211
4212       // When using -z now, we can treat .got as a relro section.
4213       // Without -z now, it is modified after program startup by lazy
4214       // PLT relocations.
4215       bool is_got_relro = parameters->options().now();
4216       Output_section_order got_order = (is_got_relro
4217                                         ? ORDER_RELRO_LAST
4218                                         : ORDER_DATA);
4219
4220       // Unlike some targets (.e.g x86), ARM does not use separate .got and
4221       // .got.plt sections in output.  The output .got section contains both
4222       // PLT and non-PLT GOT entries.
4223       this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4224
4225       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4226                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4227                                       this->got_, got_order, is_got_relro);
4228
4229       // The old GNU linker creates a .got.plt section.  We just
4230       // create another set of data in the .got section.  Note that we
4231       // always create a PLT if we create a GOT, although the PLT
4232       // might be empty.
4233       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4234       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4235                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4236                                       this->got_plt_, got_order, is_got_relro);
4237
4238       // The first three entries are reserved.
4239       this->got_plt_->set_current_data_size(3 * 4);
4240
4241       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4242       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4243                                     Symbol_table::PREDEFINED,
4244                                     this->got_plt_,
4245                                     0, 0, elfcpp::STT_OBJECT,
4246                                     elfcpp::STB_LOCAL,
4247                                     elfcpp::STV_HIDDEN, 0,
4248                                     false, false);
4249     }
4250   return this->got_;
4251 }
4252
4253 // Get the dynamic reloc section, creating it if necessary.
4254
4255 template<bool big_endian>
4256 typename Target_arm<big_endian>::Reloc_section*
4257 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4258 {
4259   if (this->rel_dyn_ == NULL)
4260     {
4261       gold_assert(layout != NULL);
4262       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4263       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4264                                       elfcpp::SHF_ALLOC, this->rel_dyn_,
4265                                       ORDER_DYNAMIC_RELOCS, false);
4266     }
4267   return this->rel_dyn_;
4268 }
4269
4270 // Insn_template methods.
4271
4272 // Return byte size of an instruction template.
4273
4274 size_t
4275 Insn_template::size() const
4276 {
4277   switch (this->type())
4278     {
4279     case THUMB16_TYPE:
4280     case THUMB16_SPECIAL_TYPE:
4281       return 2;
4282     case ARM_TYPE:
4283     case THUMB32_TYPE:
4284     case DATA_TYPE:
4285       return 4;
4286     default:
4287       gold_unreachable();
4288     }
4289 }
4290
4291 // Return alignment of an instruction template.
4292
4293 unsigned
4294 Insn_template::alignment() const
4295 {
4296   switch (this->type())
4297     {
4298     case THUMB16_TYPE:
4299     case THUMB16_SPECIAL_TYPE:
4300     case THUMB32_TYPE:
4301       return 2;
4302     case ARM_TYPE:
4303     case DATA_TYPE:
4304       return 4;
4305     default:
4306       gold_unreachable();
4307     }
4308 }
4309
4310 // Stub_template methods.
4311
4312 Stub_template::Stub_template(
4313     Stub_type type, const Insn_template* insns,
4314      size_t insn_count)
4315   : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4316     entry_in_thumb_mode_(false), relocs_()
4317 {
4318   off_t offset = 0;
4319
4320   // Compute byte size and alignment of stub template.
4321   for (size_t i = 0; i < insn_count; i++)
4322     {
4323       unsigned insn_alignment = insns[i].alignment();
4324       size_t insn_size = insns[i].size();
4325       gold_assert((offset & (insn_alignment - 1)) == 0);
4326       this->alignment_ = std::max(this->alignment_, insn_alignment);
4327       switch (insns[i].type())
4328         {
4329         case Insn_template::THUMB16_TYPE:
4330         case Insn_template::THUMB16_SPECIAL_TYPE:
4331           if (i == 0)
4332             this->entry_in_thumb_mode_ = true;
4333           break;
4334
4335         case Insn_template::THUMB32_TYPE:
4336           if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4337             this->relocs_.push_back(Reloc(i, offset));
4338           if (i == 0)
4339             this->entry_in_thumb_mode_ = true;
4340           break;
4341
4342         case Insn_template::ARM_TYPE:
4343           // Handle cases where the target is encoded within the
4344           // instruction.
4345           if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4346             this->relocs_.push_back(Reloc(i, offset));
4347           break;
4348
4349         case Insn_template::DATA_TYPE:
4350           // Entry point cannot be data.
4351           gold_assert(i != 0);
4352           this->relocs_.push_back(Reloc(i, offset));
4353           break;
4354
4355         default:
4356           gold_unreachable();
4357         }
4358       offset += insn_size;
4359     }
4360   this->size_ = offset;
4361 }
4362
4363 // Stub methods.
4364
4365 // Template to implement do_write for a specific target endianness.
4366
4367 template<bool big_endian>
4368 void inline
4369 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4370 {
4371   const Stub_template* stub_template = this->stub_template();
4372   const Insn_template* insns = stub_template->insns();
4373
4374   // FIXME:  We do not handle BE8 encoding yet.
4375   unsigned char* pov = view;
4376   for (size_t i = 0; i < stub_template->insn_count(); i++)
4377     {
4378       switch (insns[i].type())
4379         {
4380         case Insn_template::THUMB16_TYPE:
4381           elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4382           break;
4383         case Insn_template::THUMB16_SPECIAL_TYPE:
4384           elfcpp::Swap<16, big_endian>::writeval(
4385               pov,
4386               this->thumb16_special(i));
4387           break;
4388         case Insn_template::THUMB32_TYPE:
4389           {
4390             uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4391             uint32_t lo = insns[i].data() & 0xffff;
4392             elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4393             elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4394           }
4395           break;
4396         case Insn_template::ARM_TYPE:
4397         case Insn_template::DATA_TYPE:
4398           elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4399           break;
4400         default:
4401           gold_unreachable();
4402         }
4403       pov += insns[i].size();
4404     }
4405   gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4406 }
4407
4408 // Reloc_stub::Key methods.
4409
4410 // Dump a Key as a string for debugging.
4411
4412 std::string
4413 Reloc_stub::Key::name() const
4414 {
4415   if (this->r_sym_ == invalid_index)
4416     {
4417       // Global symbol key name
4418       // <stub-type>:<symbol name>:<addend>.
4419       const std::string sym_name = this->u_.symbol->name();
4420       // We need to print two hex number and two colons.  So just add 100 bytes
4421       // to the symbol name size.
4422       size_t len = sym_name.size() + 100;
4423       char* buffer = new char[len];
4424       int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4425                        sym_name.c_str(), this->addend_);
4426       gold_assert(c > 0 && c < static_cast<int>(len));
4427       delete[] buffer;
4428       return std::string(buffer);
4429     }
4430   else
4431     {
4432       // local symbol key name
4433       // <stub-type>:<object>:<r_sym>:<addend>.
4434       const size_t len = 200;
4435       char buffer[len];
4436       int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4437                        this->u_.relobj, this->r_sym_, this->addend_);
4438       gold_assert(c > 0 && c < static_cast<int>(len));
4439       return std::string(buffer);
4440     }
4441 }
4442
4443 // Reloc_stub methods.
4444
4445 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4446 // LOCATION to DESTINATION.
4447 // This code is based on the arm_type_of_stub function in
4448 // bfd/elf32-arm.c.  We have changed the interface a little to keep the Stub
4449 // class simple.
4450
4451 Stub_type
4452 Reloc_stub::stub_type_for_reloc(
4453    unsigned int r_type,
4454    Arm_address location,
4455    Arm_address destination,
4456    bool target_is_thumb)
4457 {
4458   Stub_type stub_type = arm_stub_none;
4459
4460   // This is a bit ugly but we want to avoid using a templated class for
4461   // big and little endianities.
4462   bool may_use_blx;
4463   bool should_force_pic_veneer;
4464   bool thumb2;
4465   bool thumb_only;
4466   if (parameters->target().is_big_endian())
4467     {
4468       const Target_arm<true>* big_endian_target =
4469         Target_arm<true>::default_target();
4470       may_use_blx = big_endian_target->may_use_v5t_interworking();
4471       should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4472       thumb2 = big_endian_target->using_thumb2();
4473       thumb_only = big_endian_target->using_thumb_only();
4474     }
4475   else
4476     {
4477       const Target_arm<false>* little_endian_target =
4478         Target_arm<false>::default_target();
4479       may_use_blx = little_endian_target->may_use_v5t_interworking();
4480       should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4481       thumb2 = little_endian_target->using_thumb2();
4482       thumb_only = little_endian_target->using_thumb_only();
4483     }
4484
4485   int64_t branch_offset;
4486   bool output_is_position_independent =
4487       parameters->options().output_is_position_independent();
4488   if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4489     {
4490       // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4491       // base address (instruction address + 4).
4492       if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4493         destination = Bits<32>::bit_select32(destination, location, 0x2);
4494       branch_offset = static_cast<int64_t>(destination) - location;
4495
4496       // Handle cases where:
4497       // - this call goes too far (different Thumb/Thumb2 max
4498       //   distance)
4499       // - it's a Thumb->Arm call and blx is not available, or it's a
4500       //   Thumb->Arm branch (not bl). A stub is needed in this case.
4501       if ((!thumb2
4502             && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4503                 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4504           || (thumb2
4505               && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4506                   || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4507           || ((!target_is_thumb)
4508               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4509                   || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4510         {
4511           if (target_is_thumb)
4512             {
4513               // Thumb to thumb.
4514               if (!thumb_only)
4515                 {
4516                   stub_type = (output_is_position_independent
4517                                || should_force_pic_veneer)
4518                     // PIC stubs.
4519                     ? ((may_use_blx
4520                         && (r_type == elfcpp::R_ARM_THM_CALL))
4521                        // V5T and above. Stub starts with ARM code, so
4522                        // we must be able to switch mode before
4523                        // reaching it, which is only possible for 'bl'
4524                        // (ie R_ARM_THM_CALL relocation).
4525                        ? arm_stub_long_branch_any_thumb_pic
4526                        // On V4T, use Thumb code only.
4527                        : arm_stub_long_branch_v4t_thumb_thumb_pic)
4528
4529                     // non-PIC stubs.
4530                     : ((may_use_blx
4531                         && (r_type == elfcpp::R_ARM_THM_CALL))
4532                        ? arm_stub_long_branch_any_any // V5T and above.
4533                        : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4534                 }
4535               else
4536                 {
4537                   stub_type = (output_is_position_independent
4538                                || should_force_pic_veneer)
4539                     ? arm_stub_long_branch_thumb_only_pic       // PIC stub.
4540                     : arm_stub_long_branch_thumb_only;  // non-PIC stub.
4541                 }
4542             }
4543           else
4544             {
4545               // Thumb to arm.
4546
4547               // FIXME: We should check that the input section is from an
4548               // object that has interwork enabled.
4549
4550               stub_type = (output_is_position_independent
4551                            || should_force_pic_veneer)
4552                 // PIC stubs.
4553                 ? ((may_use_blx
4554                     && (r_type == elfcpp::R_ARM_THM_CALL))
4555                    ? arm_stub_long_branch_any_arm_pic   // V5T and above.
4556                    : arm_stub_long_branch_v4t_thumb_arm_pic)    // V4T.
4557
4558                 // non-PIC stubs.
4559                 : ((may_use_blx
4560                     && (r_type == elfcpp::R_ARM_THM_CALL))
4561                    ? arm_stub_long_branch_any_any       // V5T and above.
4562                    : arm_stub_long_branch_v4t_thumb_arm);       // V4T.
4563
4564               // Handle v4t short branches.
4565               if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4566                   && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4567                   && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4568                 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4569             }
4570         }
4571     }
4572   else if (r_type == elfcpp::R_ARM_CALL
4573            || r_type == elfcpp::R_ARM_JUMP24
4574            || r_type == elfcpp::R_ARM_PLT32)
4575     {
4576       branch_offset = static_cast<int64_t>(destination) - location;
4577       if (target_is_thumb)
4578         {
4579           // Arm to thumb.
4580
4581           // FIXME: We should check that the input section is from an
4582           // object that has interwork enabled.
4583
4584           // We have an extra 2-bytes reach because of
4585           // the mode change (bit 24 (H) of BLX encoding).
4586           if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4587               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4588               || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4589               || (r_type == elfcpp::R_ARM_JUMP24)
4590               || (r_type == elfcpp::R_ARM_PLT32))
4591             {
4592               stub_type = (output_is_position_independent
4593                            || should_force_pic_veneer)
4594                 // PIC stubs.
4595                 ? (may_use_blx
4596                    ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4597                    : arm_stub_long_branch_v4t_arm_thumb_pic)    // V4T stub.
4598
4599                 // non-PIC stubs.
4600                 : (may_use_blx
4601                    ? arm_stub_long_branch_any_any       // V5T and above.
4602                    : arm_stub_long_branch_v4t_arm_thumb);       // V4T.
4603             }
4604         }
4605       else
4606         {
4607           // Arm to arm.
4608           if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4609               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4610             {
4611               stub_type = (output_is_position_independent
4612                            || should_force_pic_veneer)
4613                 ? arm_stub_long_branch_any_arm_pic      // PIC stubs.
4614                 : arm_stub_long_branch_any_any;         /// non-PIC.
4615             }
4616         }
4617     }
4618
4619   return stub_type;
4620 }
4621
4622 // Cortex_a8_stub methods.
4623
4624 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4625 // I is the position of the instruction template in the stub template.
4626
4627 uint16_t
4628 Cortex_a8_stub::do_thumb16_special(size_t i)
4629 {
4630   // The only use of this is to copy condition code from a conditional
4631   // branch being worked around to the corresponding conditional branch in
4632   // to the stub.
4633   gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4634               && i == 0);
4635   uint16_t data = this->stub_template()->insns()[i].data();
4636   gold_assert((data & 0xff00U) == 0xd000U);
4637   data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4638   return data;
4639 }
4640
4641 // Stub_factory methods.
4642
4643 Stub_factory::Stub_factory()
4644 {
4645   // The instruction template sequences are declared as static
4646   // objects and initialized first time the constructor runs.
4647
4648   // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4649   // to reach the stub if necessary.
4650   static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4651     {
4652       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4653       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4654                                                 // dcd   R_ARM_ABS32(X)
4655     };
4656
4657   // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4658   // available.
4659   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4660     {
4661       Insn_template::arm_insn(0xe59fc000),      // ldr   ip, [pc, #0]
4662       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4663       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4664                                                 // dcd   R_ARM_ABS32(X)
4665     };
4666
4667   // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4668   static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4669     {
4670       Insn_template::thumb16_insn(0xb401),      // push {r0}
4671       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4672       Insn_template::thumb16_insn(0x4684),      // mov  ip, r0
4673       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4674       Insn_template::thumb16_insn(0x4760),      // bx   ip
4675       Insn_template::thumb16_insn(0xbf00),      // nop
4676       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4677                                                 // dcd  R_ARM_ABS32(X)
4678     };
4679
4680   // V4T Thumb -> Thumb long branch stub. Using the stack is not
4681   // allowed.
4682   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4683     {
4684       Insn_template::thumb16_insn(0x4778),      // bx   pc
4685       Insn_template::thumb16_insn(0x46c0),      // nop
4686       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4687       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4688       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4689                                                 // dcd  R_ARM_ABS32(X)
4690     };
4691
4692   // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4693   // available.
4694   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4695     {
4696       Insn_template::thumb16_insn(0x4778),      // bx   pc
4697       Insn_template::thumb16_insn(0x46c0),      // nop
4698       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4699       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4700                                                 // dcd   R_ARM_ABS32(X)
4701     };
4702
4703   // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4704   // one, when the destination is close enough.
4705   static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4706     {
4707       Insn_template::thumb16_insn(0x4778),              // bx   pc
4708       Insn_template::thumb16_insn(0x46c0),              // nop
4709       Insn_template::arm_rel_insn(0xea000000, -8),      // b    (X-8)
4710     };
4711
4712   // ARM/Thumb -> ARM long branch stub, PIC.  On V5T and above, use
4713   // blx to reach the stub if necessary.
4714   static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4715     {
4716       Insn_template::arm_insn(0xe59fc000),      // ldr   r12, [pc]
4717       Insn_template::arm_insn(0xe08ff00c),      // add   pc, pc, ip
4718       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4719                                                 // dcd   R_ARM_REL32(X-4)
4720     };
4721
4722   // ARM/Thumb -> Thumb long branch stub, PIC.  On V5T and above, use
4723   // blx to reach the stub if necessary.  We can not add into pc;
4724   // it is not guaranteed to mode switch (different in ARMv6 and
4725   // ARMv7).
4726   static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4727     {
4728       Insn_template::arm_insn(0xe59fc004),      // ldr   r12, [pc, #4]
4729       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4730       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4731       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4732                                                 // dcd   R_ARM_REL32(X)
4733     };
4734
4735   // V4T ARM -> ARM long branch stub, PIC.
4736   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4737     {
4738       Insn_template::arm_insn(0xe59fc004),      // ldr   ip, [pc, #4]
4739       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4740       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4741       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4742                                                 // dcd   R_ARM_REL32(X)
4743     };
4744
4745   // V4T Thumb -> ARM long branch stub, PIC.
4746   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4747     {
4748       Insn_template::thumb16_insn(0x4778),      // bx   pc
4749       Insn_template::thumb16_insn(0x46c0),      // nop
4750       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4751       Insn_template::arm_insn(0xe08cf00f),      // add  pc, ip, pc
4752       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4753                                                 // dcd  R_ARM_REL32(X)
4754     };
4755
4756   // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4757   // architectures.
4758   static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4759     {
4760       Insn_template::thumb16_insn(0xb401),      // push {r0}
4761       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4762       Insn_template::thumb16_insn(0x46fc),      // mov  ip, pc
4763       Insn_template::thumb16_insn(0x4484),      // add  ip, r0
4764       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4765       Insn_template::thumb16_insn(0x4760),      // bx   ip
4766       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4767                                                 // dcd  R_ARM_REL32(X)
4768     };
4769
4770   // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4771   // allowed.
4772   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4773     {
4774       Insn_template::thumb16_insn(0x4778),      // bx   pc
4775       Insn_template::thumb16_insn(0x46c0),      // nop
4776       Insn_template::arm_insn(0xe59fc004),      // ldr  ip, [pc, #4]
4777       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4778       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4779       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4780                                                 // dcd  R_ARM_REL32(X)
4781     };
4782
4783   // Cortex-A8 erratum-workaround stubs.
4784
4785   // Stub used for conditional branches (which may be beyond +/-1MB away,
4786   // so we can't use a conditional branch to reach this stub).
4787
4788   // original code:
4789   //
4790   //    b<cond> X
4791   // after:
4792   //
4793   static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4794     {
4795       Insn_template::thumb16_bcond_insn(0xd001),        //      b<cond>.n true
4796       Insn_template::thumb32_b_insn(0xf000b800, -4),    //      b.w after
4797       Insn_template::thumb32_b_insn(0xf000b800, -4)     // true:
4798                                                         //      b.w X
4799     };
4800
4801   // Stub used for b.w and bl.w instructions.
4802
4803   static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4804     {
4805       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4806     };
4807
4808   static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4809     {
4810       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4811     };
4812
4813   // Stub used for Thumb-2 blx.w instructions.  We modified the original blx.w
4814   // instruction (which switches to ARM mode) to point to this stub.  Jump to
4815   // the real destination using an ARM-mode branch.
4816   static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4817     {
4818       Insn_template::arm_rel_insn(0xea000000, -8)       // b dest
4819     };
4820
4821   // Stub used to provide an interworking for R_ARM_V4BX relocation
4822   // (bx r[n] instruction).
4823   static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4824     {
4825       Insn_template::arm_insn(0xe3100001),              // tst   r<n>, #1
4826       Insn_template::arm_insn(0x01a0f000),              // moveq pc, r<n>
4827       Insn_template::arm_insn(0xe12fff10)               // bx    r<n>
4828     };
4829
4830   // Fill in the stub template look-up table.  Stub templates are constructed
4831   // per instance of Stub_factory for fast look-up without locking
4832   // in a thread-enabled environment.
4833
4834   this->stub_templates_[arm_stub_none] =
4835     new Stub_template(arm_stub_none, NULL, 0);
4836
4837 #define DEF_STUB(x)     \
4838   do \
4839     { \
4840       size_t array_size \
4841         = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4842       Stub_type type = arm_stub_##x; \
4843       this->stub_templates_[type] = \
4844         new Stub_template(type, elf32_arm_stub_##x, array_size); \
4845     } \
4846   while (0);
4847
4848   DEF_STUBS
4849 #undef DEF_STUB
4850 }
4851
4852 // Stub_table methods.
4853
4854 // Remove all Cortex-A8 stub.
4855
4856 template<bool big_endian>
4857 void
4858 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4859 {
4860   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4861        p != this->cortex_a8_stubs_.end();
4862        ++p)
4863     delete p->second;
4864   this->cortex_a8_stubs_.clear();
4865 }
4866
4867 // Relocate one stub.  This is a helper for Stub_table::relocate_stubs().
4868
4869 template<bool big_endian>
4870 void
4871 Stub_table<big_endian>::relocate_stub(
4872     Stub* stub,
4873     const Relocate_info<32, big_endian>* relinfo,
4874     Target_arm<big_endian>* arm_target,
4875     Output_section* output_section,
4876     unsigned char* view,
4877     Arm_address address,
4878     section_size_type view_size)
4879 {
4880   const Stub_template* stub_template = stub->stub_template();
4881   if (stub_template->reloc_count() != 0)
4882     {
4883       // Adjust view to cover the stub only.
4884       section_size_type offset = stub->offset();
4885       section_size_type stub_size = stub_template->size();
4886       gold_assert(offset + stub_size <= view_size);
4887
4888       arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4889                                 address + offset, stub_size);
4890     }
4891 }
4892
4893 // Relocate all stubs in this stub table.
4894
4895 template<bool big_endian>
4896 void
4897 Stub_table<big_endian>::relocate_stubs(
4898     const Relocate_info<32, big_endian>* relinfo,
4899     Target_arm<big_endian>* arm_target,
4900     Output_section* output_section,
4901     unsigned char* view,
4902     Arm_address address,
4903     section_size_type view_size)
4904 {
4905   // If we are passed a view bigger than the stub table's.  we need to
4906   // adjust the view.
4907   gold_assert(address == this->address()
4908               && (view_size
4909                   == static_cast<section_size_type>(this->data_size())));
4910
4911   // Relocate all relocation stubs.
4912   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4913       p != this->reloc_stubs_.end();
4914       ++p)
4915     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4916                         address, view_size);
4917
4918   // Relocate all Cortex-A8 stubs.
4919   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4920        p != this->cortex_a8_stubs_.end();
4921        ++p)
4922     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4923                         address, view_size);
4924
4925   // Relocate all ARM V4BX stubs.
4926   for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4927        p != this->arm_v4bx_stubs_.end();
4928        ++p)
4929     {
4930       if (*p != NULL)
4931         this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4932                             address, view_size);
4933     }
4934 }
4935
4936 // Write out the stubs to file.
4937
4938 template<bool big_endian>
4939 void
4940 Stub_table<big_endian>::do_write(Output_file* of)
4941 {
4942   off_t offset = this->offset();
4943   const section_size_type oview_size =
4944     convert_to_section_size_type(this->data_size());
4945   unsigned char* const oview = of->get_output_view(offset, oview_size);
4946
4947   // Write relocation stubs.
4948   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4949       p != this->reloc_stubs_.end();
4950       ++p)
4951     {
4952       Reloc_stub* stub = p->second;
4953       Arm_address address = this->address() + stub->offset();
4954       gold_assert(address
4955                   == align_address(address,
4956                                    stub->stub_template()->alignment()));
4957       stub->write(oview + stub->offset(), stub->stub_template()->size(),
4958                   big_endian);
4959     }
4960
4961   // Write Cortex-A8 stubs.
4962   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4963        p != this->cortex_a8_stubs_.end();
4964        ++p)
4965     {
4966       Cortex_a8_stub* stub = p->second;
4967       Arm_address address = this->address() + stub->offset();
4968       gold_assert(address
4969                   == align_address(address,
4970                                    stub->stub_template()->alignment()));
4971       stub->write(oview + stub->offset(), stub->stub_template()->size(),
4972                   big_endian);
4973     }
4974
4975   // Write ARM V4BX relocation stubs.
4976   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4977        p != this->arm_v4bx_stubs_.end();
4978        ++p)
4979     {
4980       if (*p == NULL)
4981         continue;
4982
4983       Arm_address address = this->address() + (*p)->offset();
4984       gold_assert(address
4985                   == align_address(address,
4986                                    (*p)->stub_template()->alignment()));
4987       (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4988                   big_endian);
4989     }
4990
4991   of->write_output_view(this->offset(), oview_size, oview);
4992 }
4993
4994 // Update the data size and address alignment of the stub table at the end
4995 // of a relaxation pass.   Return true if either the data size or the
4996 // alignment changed in this relaxation pass.
4997
4998 template<bool big_endian>
4999 bool
5000 Stub_table<big_endian>::update_data_size_and_addralign()
5001 {
5002   // Go over all stubs in table to compute data size and address alignment.
5003   off_t size = this->reloc_stubs_size_;
5004   unsigned addralign = this->reloc_stubs_addralign_;
5005
5006   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5007        p != this->cortex_a8_stubs_.end();
5008        ++p)
5009     {
5010       const Stub_template* stub_template = p->second->stub_template();
5011       addralign = std::max(addralign, stub_template->alignment());
5012       size = (align_address(size, stub_template->alignment())
5013               + stub_template->size());
5014     }
5015
5016   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5017        p != this->arm_v4bx_stubs_.end();
5018        ++p)
5019     {
5020       if (*p == NULL)
5021         continue;
5022
5023       const Stub_template* stub_template = (*p)->stub_template();
5024       addralign = std::max(addralign, stub_template->alignment());
5025       size = (align_address(size, stub_template->alignment())
5026               + stub_template->size());
5027     }
5028
5029   // Check if either data size or alignment changed in this pass.
5030   // Update prev_data_size_ and prev_addralign_.  These will be used
5031   // as the current data size and address alignment for the next pass.
5032   bool changed = size != this->prev_data_size_;
5033   this->prev_data_size_ = size;
5034
5035   if (addralign != this->prev_addralign_)
5036     changed = true;
5037   this->prev_addralign_ = addralign;
5038
5039   return changed;
5040 }
5041
5042 // Finalize the stubs.  This sets the offsets of the stubs within the stub
5043 // table.  It also marks all input sections needing Cortex-A8 workaround.
5044
5045 template<bool big_endian>
5046 void
5047 Stub_table<big_endian>::finalize_stubs()
5048 {
5049   off_t off = this->reloc_stubs_size_;
5050   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5051        p != this->cortex_a8_stubs_.end();
5052        ++p)
5053     {
5054       Cortex_a8_stub* stub = p->second;
5055       const Stub_template* stub_template = stub->stub_template();
5056       uint64_t stub_addralign = stub_template->alignment();
5057       off = align_address(off, stub_addralign);
5058       stub->set_offset(off);
5059       off += stub_template->size();
5060
5061       // Mark input section so that we can determine later if a code section
5062       // needs the Cortex-A8 workaround quickly.
5063       Arm_relobj<big_endian>* arm_relobj =
5064         Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5065       arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5066     }
5067
5068   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5069       p != this->arm_v4bx_stubs_.end();
5070       ++p)
5071     {
5072       if (*p == NULL)
5073         continue;
5074
5075       const Stub_template* stub_template = (*p)->stub_template();
5076       uint64_t stub_addralign = stub_template->alignment();
5077       off = align_address(off, stub_addralign);
5078       (*p)->set_offset(off);
5079       off += stub_template->size();
5080     }
5081
5082   gold_assert(off <= this->prev_data_size_);
5083 }
5084
5085 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5086 // and VIEW_ADDRESS + VIEW_SIZE - 1.  VIEW points to the mapped address
5087 // of the address range seen by the linker.
5088
5089 template<bool big_endian>
5090 void
5091 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5092     Target_arm<big_endian>* arm_target,
5093     unsigned char* view,
5094     Arm_address view_address,
5095     section_size_type view_size)
5096 {
5097   // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5098   for (Cortex_a8_stub_list::const_iterator p =
5099          this->cortex_a8_stubs_.lower_bound(view_address);
5100        ((p != this->cortex_a8_stubs_.end())
5101         && (p->first < (view_address + view_size)));
5102        ++p)
5103     {
5104       // We do not store the THUMB bit in the LSB of either the branch address
5105       // or the stub offset.  There is no need to strip the LSB.
5106       Arm_address branch_address = p->first;
5107       const Cortex_a8_stub* stub = p->second;
5108       Arm_address stub_address = this->address() + stub->offset();
5109
5110       // Offset of the branch instruction relative to this view.
5111       section_size_type offset =
5112         convert_to_section_size_type(branch_address - view_address);
5113       gold_assert((offset + 4) <= view_size);
5114
5115       arm_target->apply_cortex_a8_workaround(stub, stub_address,
5116                                              view + offset, branch_address);
5117     }
5118 }
5119
5120 // Arm_input_section methods.
5121
5122 // Initialize an Arm_input_section.
5123
5124 template<bool big_endian>
5125 void
5126 Arm_input_section<big_endian>::init()
5127 {
5128   Relobj* relobj = this->relobj();
5129   unsigned int shndx = this->shndx();
5130
5131   // We have to cache original size, alignment and contents to avoid locking
5132   // the original file.
5133   this->original_addralign_ =
5134     convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5135
5136   // This is not efficient but we expect only a small number of relaxed
5137   // input sections for stubs.
5138   section_size_type section_size;
5139   const unsigned char* section_contents =
5140     relobj->section_contents(shndx, &section_size, false);
5141   this->original_size_ =
5142     convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5143
5144   gold_assert(this->original_contents_ == NULL);
5145   this->original_contents_ = new unsigned char[section_size];
5146   memcpy(this->original_contents_, section_contents, section_size);
5147
5148   // We want to make this look like the original input section after
5149   // output sections are finalized.
5150   Output_section* os = relobj->output_section(shndx);
5151   off_t offset = relobj->output_section_offset(shndx);
5152   gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5153   this->set_address(os->address() + offset);
5154   this->set_file_offset(os->offset() + offset);
5155
5156   this->set_current_data_size(this->original_size_);
5157   this->finalize_data_size();
5158 }
5159
5160 template<bool big_endian>
5161 void
5162 Arm_input_section<big_endian>::do_write(Output_file* of)
5163 {
5164   // We have to write out the original section content.
5165   gold_assert(this->original_contents_ != NULL);
5166   of->write(this->offset(), this->original_contents_,
5167             this->original_size_);
5168
5169   // If this owns a stub table and it is not empty, write it.
5170   if (this->is_stub_table_owner() && !this->stub_table_->empty())
5171     this->stub_table_->write(of);
5172 }
5173
5174 // Finalize data size.
5175
5176 template<bool big_endian>
5177 void
5178 Arm_input_section<big_endian>::set_final_data_size()
5179 {
5180   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5181
5182   if (this->is_stub_table_owner())
5183     {
5184       this->stub_table_->finalize_data_size();
5185       off = align_address(off, this->stub_table_->addralign());
5186       off += this->stub_table_->data_size();
5187     }
5188   this->set_data_size(off);
5189 }
5190
5191 // Reset address and file offset.
5192
5193 template<bool big_endian>
5194 void
5195 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5196 {
5197   // Size of the original input section contents.
5198   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5199
5200   // If this is a stub table owner, account for the stub table size.
5201   if (this->is_stub_table_owner())
5202     {
5203       Stub_table<big_endian>* stub_table = this->stub_table_;
5204
5205       // Reset the stub table's address and file offset.  The
5206       // current data size for child will be updated after that.
5207       stub_table_->reset_address_and_file_offset();
5208       off = align_address(off, stub_table_->addralign());
5209       off += stub_table->current_data_size();
5210     }
5211
5212   this->set_current_data_size(off);
5213 }
5214
5215 // Arm_exidx_cantunwind methods.
5216
5217 // Write this to Output file OF for a fixed endianness.
5218
5219 template<bool big_endian>
5220 void
5221 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5222 {
5223   off_t offset = this->offset();
5224   const section_size_type oview_size = 8;
5225   unsigned char* const oview = of->get_output_view(offset, oview_size);
5226
5227   Output_section* os = this->relobj_->output_section(this->shndx_);
5228   gold_assert(os != NULL);
5229
5230   Arm_relobj<big_endian>* arm_relobj =
5231     Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5232   Arm_address output_offset =
5233     arm_relobj->get_output_section_offset(this->shndx_);
5234   Arm_address section_start;
5235   section_size_type section_size;
5236
5237   // Find out the end of the text section referred by this.
5238   if (output_offset != Arm_relobj<big_endian>::invalid_address)
5239     {
5240       section_start = os->address() + output_offset;
5241       const Arm_exidx_input_section* exidx_input_section =
5242         arm_relobj->exidx_input_section_by_link(this->shndx_);
5243       gold_assert(exidx_input_section != NULL);
5244       section_size =
5245         convert_to_section_size_type(exidx_input_section->text_size());
5246     }
5247   else
5248     {
5249       // Currently this only happens for a relaxed section.
5250       const Output_relaxed_input_section* poris =
5251         os->find_relaxed_input_section(this->relobj_, this->shndx_);
5252       gold_assert(poris != NULL);
5253       section_start = poris->address();
5254       section_size = convert_to_section_size_type(poris->data_size());
5255     }
5256
5257   // We always append this to the end of an EXIDX section.
5258   Arm_address output_address = section_start + section_size;
5259
5260   // Write out the entry.  The first word either points to the beginning
5261   // or after the end of a text section.  The second word is the special
5262   // EXIDX_CANTUNWIND value.
5263   uint32_t prel31_offset = output_address - this->address();
5264   if (Bits<31>::has_overflow32(offset))
5265     gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5266   elfcpp::Swap_unaligned<32, big_endian>::writeval(oview,
5267                                                    prel31_offset & 0x7fffffffU);
5268   elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4,
5269                                                    elfcpp::EXIDX_CANTUNWIND);
5270
5271   of->write_output_view(this->offset(), oview_size, oview);
5272 }
5273
5274 // Arm_exidx_merged_section methods.
5275
5276 // Constructor for Arm_exidx_merged_section.
5277 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5278 // SECTION_OFFSET_MAP points to a section offset map describing how
5279 // parts of the input section are mapped to output.  DELETED_BYTES is
5280 // the number of bytes deleted from the EXIDX input section.
5281
5282 Arm_exidx_merged_section::Arm_exidx_merged_section(
5283     const Arm_exidx_input_section& exidx_input_section,
5284     const Arm_exidx_section_offset_map& section_offset_map,
5285     uint32_t deleted_bytes)
5286   : Output_relaxed_input_section(exidx_input_section.relobj(),
5287                                  exidx_input_section.shndx(),
5288                                  exidx_input_section.addralign()),
5289     exidx_input_section_(exidx_input_section),
5290     section_offset_map_(section_offset_map)
5291 {
5292   // If we retain or discard the whole EXIDX input section,  we would
5293   // not be here.
5294   gold_assert(deleted_bytes != 0
5295               && deleted_bytes != this->exidx_input_section_.size());
5296
5297   // Fix size here so that we do not need to implement set_final_data_size.
5298   uint32_t size = exidx_input_section.size() - deleted_bytes;
5299   this->set_data_size(size);
5300   this->fix_data_size();
5301
5302   // Allocate buffer for section contents and build contents.
5303   this->section_contents_ = new unsigned char[size];
5304 }
5305
5306 // Build the contents of a merged EXIDX output section.
5307
5308 void
5309 Arm_exidx_merged_section::build_contents(
5310     const unsigned char* original_contents,
5311     section_size_type original_size)
5312 {
5313   // Go over spans of input offsets and write only those that are not
5314   // discarded.
5315   section_offset_type in_start = 0;
5316   section_offset_type out_start = 0;
5317   section_offset_type in_max =
5318     convert_types<section_offset_type>(original_size);
5319   section_offset_type out_max =
5320     convert_types<section_offset_type>(this->data_size());
5321   for (Arm_exidx_section_offset_map::const_iterator p =
5322         this->section_offset_map_.begin();
5323       p != this->section_offset_map_.end();
5324       ++p)
5325     {
5326       section_offset_type in_end = p->first;
5327       gold_assert(in_end >= in_start);
5328       section_offset_type out_end = p->second;
5329       size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5330       if (out_end != -1)
5331         {
5332           size_t out_chunk_size =
5333             convert_types<size_t>(out_end - out_start + 1);
5334
5335           gold_assert(out_chunk_size == in_chunk_size
5336                       && in_end < in_max && out_end < out_max);
5337
5338           memcpy(this->section_contents_ + out_start,
5339                  original_contents + in_start,
5340                  out_chunk_size);
5341           out_start += out_chunk_size;
5342         }
5343       in_start += in_chunk_size;
5344     }
5345 }
5346
5347 // Given an input OBJECT, an input section index SHNDX within that
5348 // object, and an OFFSET relative to the start of that input
5349 // section, return whether or not the corresponding offset within
5350 // the output section is known.  If this function returns true, it
5351 // sets *POUTPUT to the output offset.  The value -1 indicates that
5352 // this input offset is being discarded.
5353
5354 bool
5355 Arm_exidx_merged_section::do_output_offset(
5356     const Relobj* relobj,
5357     unsigned int shndx,
5358     section_offset_type offset,
5359     section_offset_type* poutput) const
5360 {
5361   // We only handle offsets for the original EXIDX input section.
5362   if (relobj != this->exidx_input_section_.relobj()
5363       || shndx != this->exidx_input_section_.shndx())
5364     return false;
5365
5366   section_offset_type section_size =
5367     convert_types<section_offset_type>(this->exidx_input_section_.size());
5368   if (offset < 0 || offset >= section_size)
5369     // Input offset is out of valid range.
5370     *poutput = -1;
5371   else
5372     {
5373       // We need to look up the section offset map to determine the output
5374       // offset.  Find the reference point in map that is first offset
5375       // bigger than or equal to this offset.
5376       Arm_exidx_section_offset_map::const_iterator p =
5377         this->section_offset_map_.lower_bound(offset);
5378
5379       // The section offset maps are build such that this should not happen if
5380       // input offset is in the valid range.
5381       gold_assert(p != this->section_offset_map_.end());
5382
5383       // We need to check if this is dropped.
5384      section_offset_type ref = p->first;
5385      section_offset_type mapped_ref = p->second;
5386
5387       if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5388         // Offset is present in output.
5389         *poutput = mapped_ref + (offset - ref);
5390       else
5391         // Offset is discarded owing to EXIDX entry merging.
5392         *poutput = -1;
5393     }
5394
5395   return true;
5396 }
5397
5398 // Write this to output file OF.
5399
5400 void
5401 Arm_exidx_merged_section::do_write(Output_file* of)
5402 {
5403   off_t offset = this->offset();
5404   const section_size_type oview_size = this->data_size();
5405   unsigned char* const oview = of->get_output_view(offset, oview_size);
5406
5407   Output_section* os = this->relobj()->output_section(this->shndx());
5408   gold_assert(os != NULL);
5409
5410   memcpy(oview, this->section_contents_, oview_size);
5411   of->write_output_view(this->offset(), oview_size, oview);
5412 }
5413
5414 // Arm_exidx_fixup methods.
5415
5416 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5417 // is not an EXIDX_CANTUNWIND entry already.  The new EXIDX_CANTUNWIND entry
5418 // points to the end of the last seen EXIDX section.
5419
5420 void
5421 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5422 {
5423   if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5424       && this->last_input_section_ != NULL)
5425     {
5426       Relobj* relobj = this->last_input_section_->relobj();
5427       unsigned int text_shndx = this->last_input_section_->link();
5428       Arm_exidx_cantunwind* cantunwind =
5429         new Arm_exidx_cantunwind(relobj, text_shndx);
5430       this->exidx_output_section_->add_output_section_data(cantunwind);
5431       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5432     }
5433 }
5434
5435 // Process an EXIDX section entry in input.  Return whether this entry
5436 // can be deleted in the output.  SECOND_WORD in the second word of the
5437 // EXIDX entry.
5438
5439 bool
5440 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5441 {
5442   bool delete_entry;
5443   if (second_word == elfcpp::EXIDX_CANTUNWIND)
5444     {
5445       // Merge if previous entry is also an EXIDX_CANTUNWIND.
5446       delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5447       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5448     }
5449   else if ((second_word & 0x80000000) != 0)
5450     {
5451       // Inlined unwinding data.  Merge if equal to previous.
5452       delete_entry = (merge_exidx_entries_
5453                       && this->last_unwind_type_ == UT_INLINED_ENTRY
5454                       && this->last_inlined_entry_ == second_word);
5455       this->last_unwind_type_ = UT_INLINED_ENTRY;
5456       this->last_inlined_entry_ = second_word;
5457     }
5458   else
5459     {
5460       // Normal table entry.  In theory we could merge these too,
5461       // but duplicate entries are likely to be much less common.
5462       delete_entry = false;
5463       this->last_unwind_type_ = UT_NORMAL_ENTRY;
5464     }
5465   return delete_entry;
5466 }
5467
5468 // Update the current section offset map during EXIDX section fix-up.
5469 // If there is no map, create one.  INPUT_OFFSET is the offset of a
5470 // reference point, DELETED_BYTES is the number of deleted by in the
5471 // section so far.  If DELETE_ENTRY is true, the reference point and
5472 // all offsets after the previous reference point are discarded.
5473
5474 void
5475 Arm_exidx_fixup::update_offset_map(
5476     section_offset_type input_offset,
5477     section_size_type deleted_bytes,
5478     bool delete_entry)
5479 {
5480   if (this->section_offset_map_ == NULL)
5481     this->section_offset_map_ = new Arm_exidx_section_offset_map();
5482   section_offset_type output_offset;
5483   if (delete_entry)
5484     output_offset = Arm_exidx_input_section::invalid_offset;
5485   else
5486     output_offset = input_offset - deleted_bytes;
5487   (*this->section_offset_map_)[input_offset] = output_offset;
5488 }
5489
5490 // Process EXIDX_INPUT_SECTION for EXIDX entry merging.  Return the number of
5491 // bytes deleted.  SECTION_CONTENTS points to the contents of the EXIDX
5492 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5493 // If some entries are merged, also store a pointer to a newly created
5494 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP.  The caller
5495 // owns the map and is responsible for releasing it after use.
5496
5497 template<bool big_endian>
5498 uint32_t
5499 Arm_exidx_fixup::process_exidx_section(
5500     const Arm_exidx_input_section* exidx_input_section,
5501     const unsigned char* section_contents,
5502     section_size_type section_size,
5503     Arm_exidx_section_offset_map** psection_offset_map)
5504 {
5505   Relobj* relobj = exidx_input_section->relobj();
5506   unsigned shndx = exidx_input_section->shndx();
5507
5508   if ((section_size % 8) != 0)
5509     {
5510       // Something is wrong with this section.  Better not touch it.
5511       gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5512                  relobj->name().c_str(), shndx);
5513       this->last_input_section_ = exidx_input_section;
5514       this->last_unwind_type_ = UT_NONE;
5515       return 0;
5516     }
5517
5518   uint32_t deleted_bytes = 0;
5519   bool prev_delete_entry = false;
5520   gold_assert(this->section_offset_map_ == NULL);
5521
5522   for (section_size_type i = 0; i < section_size; i += 8)
5523     {
5524       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5525       const Valtype* wv =
5526           reinterpret_cast<const Valtype*>(section_contents + i + 4);
5527       uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5528
5529       bool delete_entry = this->process_exidx_entry(second_word);
5530
5531       // Entry deletion causes changes in output offsets.  We use a std::map
5532       // to record these.  And entry (x, y) means input offset x
5533       // is mapped to output offset y.  If y is invalid_offset, then x is
5534       // dropped in the output.  Because of the way std::map::lower_bound
5535       // works, we record the last offset in a region w.r.t to keeping or
5536       // dropping.  If there is no entry (x0, y0) for an input offset x0,
5537       // the output offset y0 of it is determined by the output offset y1 of
5538       // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5539       // in the map.  If y1 is not -1, then y0 = y1 + x0 - x1.  Otherwise, y1
5540       // y0 is also -1.
5541       if (delete_entry != prev_delete_entry && i != 0)
5542         this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5543
5544       // Update total deleted bytes for this entry.
5545       if (delete_entry)
5546         deleted_bytes += 8;
5547
5548       prev_delete_entry = delete_entry;
5549     }
5550
5551   // If section offset map is not NULL, make an entry for the end of
5552   // section.
5553   if (this->section_offset_map_ != NULL)
5554     update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5555
5556   *psection_offset_map = this->section_offset_map_;
5557   this->section_offset_map_ = NULL;
5558   this->last_input_section_ = exidx_input_section;
5559
5560   // Set the first output text section so that we can link the EXIDX output
5561   // section to it.  Ignore any EXIDX input section that is completely merged.
5562   if (this->first_output_text_section_ == NULL
5563       && deleted_bytes != section_size)
5564     {
5565       unsigned int link = exidx_input_section->link();
5566       Output_section* os = relobj->output_section(link);
5567       gold_assert(os != NULL);
5568       this->first_output_text_section_ = os;
5569     }
5570
5571   return deleted_bytes;
5572 }
5573
5574 // Arm_output_section methods.
5575
5576 // Create a stub group for input sections from BEGIN to END.  OWNER
5577 // points to the input section to be the owner a new stub table.
5578
5579 template<bool big_endian>
5580 void
5581 Arm_output_section<big_endian>::create_stub_group(
5582   Input_section_list::const_iterator begin,
5583   Input_section_list::const_iterator end,
5584   Input_section_list::const_iterator owner,
5585   Target_arm<big_endian>* target,
5586   std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5587   const Task* task)
5588 {
5589   // We use a different kind of relaxed section in an EXIDX section.
5590   // The static casting from Output_relaxed_input_section to
5591   // Arm_input_section is invalid in an EXIDX section.  We are okay
5592   // because we should not be calling this for an EXIDX section.
5593   gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5594
5595   // Currently we convert ordinary input sections into relaxed sections only
5596   // at this point but we may want to support creating relaxed input section
5597   // very early.  So we check here to see if owner is already a relaxed
5598   // section.
5599
5600   Arm_input_section<big_endian>* arm_input_section;
5601   if (owner->is_relaxed_input_section())
5602     {
5603       arm_input_section =
5604         Arm_input_section<big_endian>::as_arm_input_section(
5605           owner->relaxed_input_section());
5606     }
5607   else
5608     {
5609       gold_assert(owner->is_input_section());
5610       // Create a new relaxed input section.  We need to lock the original
5611       // file.
5612       Task_lock_obj<Object> tl(task, owner->relobj());
5613       arm_input_section =
5614         target->new_arm_input_section(owner->relobj(), owner->shndx());
5615       new_relaxed_sections->push_back(arm_input_section);
5616     }
5617
5618   // Create a stub table.
5619   Stub_table<big_endian>* stub_table =
5620     target->new_stub_table(arm_input_section);
5621
5622   arm_input_section->set_stub_table(stub_table);
5623
5624   Input_section_list::const_iterator p = begin;
5625   Input_section_list::const_iterator prev_p;
5626
5627   // Look for input sections or relaxed input sections in [begin ... end].
5628   do
5629     {
5630       if (p->is_input_section() || p->is_relaxed_input_section())
5631         {
5632           // The stub table information for input sections live
5633           // in their objects.
5634           Arm_relobj<big_endian>* arm_relobj =
5635             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5636           arm_relobj->set_stub_table(p->shndx(), stub_table);
5637         }
5638       prev_p = p++;
5639     }
5640   while (prev_p != end);
5641 }
5642
5643 // Group input sections for stub generation.  GROUP_SIZE is roughly the limit
5644 // of stub groups.  We grow a stub group by adding input section until the
5645 // size is just below GROUP_SIZE.  The last input section will be converted
5646 // into a stub table.  If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5647 // input section after the stub table, effectively double the group size.
5648 //
5649 // This is similar to the group_sections() function in elf32-arm.c but is
5650 // implemented differently.
5651
5652 template<bool big_endian>
5653 void
5654 Arm_output_section<big_endian>::group_sections(
5655     section_size_type group_size,
5656     bool stubs_always_after_branch,
5657     Target_arm<big_endian>* target,
5658     const Task* task)
5659 {
5660   // States for grouping.
5661   typedef enum
5662   {
5663     // No group is being built.
5664     NO_GROUP,
5665     // A group is being built but the stub table is not found yet.
5666     // We keep group a stub group until the size is just under GROUP_SIZE.
5667     // The last input section in the group will be used as the stub table.
5668     FINDING_STUB_SECTION,
5669     // A group is being built and we have already found a stub table.
5670     // We enter this state to grow a stub group by adding input section
5671     // after the stub table.  This effectively doubles the group size.
5672     HAS_STUB_SECTION
5673   } State;
5674
5675   // Any newly created relaxed sections are stored here.
5676   std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5677
5678   State state = NO_GROUP;
5679   section_size_type off = 0;
5680   section_size_type group_begin_offset = 0;
5681   section_size_type group_end_offset = 0;
5682   section_size_type stub_table_end_offset = 0;
5683   Input_section_list::const_iterator group_begin =
5684     this->input_sections().end();
5685   Input_section_list::const_iterator stub_table =
5686     this->input_sections().end();
5687   Input_section_list::const_iterator group_end = this->input_sections().end();
5688   for (Input_section_list::const_iterator p = this->input_sections().begin();
5689        p != this->input_sections().end();
5690        ++p)
5691     {
5692       section_size_type section_begin_offset =
5693         align_address(off, p->addralign());
5694       section_size_type section_end_offset =
5695         section_begin_offset + p->data_size();
5696
5697       // Check to see if we should group the previously seen sections.
5698       switch (state)
5699         {
5700         case NO_GROUP:
5701           break;
5702
5703         case FINDING_STUB_SECTION:
5704           // Adding this section makes the group larger than GROUP_SIZE.
5705           if (section_end_offset - group_begin_offset >= group_size)
5706             {
5707               if (stubs_always_after_branch)
5708                 {
5709                   gold_assert(group_end != this->input_sections().end());
5710                   this->create_stub_group(group_begin, group_end, group_end,
5711                                           target, &new_relaxed_sections,
5712                                           task);
5713                   state = NO_GROUP;
5714                 }
5715               else
5716                 {
5717                   // But wait, there's more!  Input sections up to
5718                   // stub_group_size bytes after the stub table can be
5719                   // handled by it too.
5720                   state = HAS_STUB_SECTION;
5721                   stub_table = group_end;
5722                   stub_table_end_offset = group_end_offset;
5723                 }
5724             }
5725             break;
5726
5727         case HAS_STUB_SECTION:
5728           // Adding this section makes the post stub-section group larger
5729           // than GROUP_SIZE.
5730           if (section_end_offset - stub_table_end_offset >= group_size)
5731            {
5732              gold_assert(group_end != this->input_sections().end());
5733              this->create_stub_group(group_begin, group_end, stub_table,
5734                                      target, &new_relaxed_sections, task);
5735              state = NO_GROUP;
5736            }
5737            break;
5738
5739           default:
5740             gold_unreachable();
5741         }
5742
5743       // If we see an input section and currently there is no group, start
5744       // a new one.  Skip any empty sections.  We look at the data size
5745       // instead of calling p->relobj()->section_size() to avoid locking.
5746       if ((p->is_input_section() || p->is_relaxed_input_section())
5747           && (p->data_size() != 0))
5748         {
5749           if (state == NO_GROUP)
5750             {
5751               state = FINDING_STUB_SECTION;
5752               group_begin = p;
5753               group_begin_offset = section_begin_offset;
5754             }
5755
5756           // Keep track of the last input section seen.
5757           group_end = p;
5758           group_end_offset = section_end_offset;
5759         }
5760
5761       off = section_end_offset;
5762     }
5763
5764   // Create a stub group for any ungrouped sections.
5765   if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5766     {
5767       gold_assert(group_end != this->input_sections().end());
5768       this->create_stub_group(group_begin, group_end,
5769                               (state == FINDING_STUB_SECTION
5770                                ? group_end
5771                                : stub_table),
5772                                target, &new_relaxed_sections, task);
5773     }
5774
5775   // Convert input section into relaxed input section in a batch.
5776   if (!new_relaxed_sections.empty())
5777     this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5778
5779   // Update the section offsets
5780   for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5781     {
5782       Arm_relobj<big_endian>* arm_relobj =
5783         Arm_relobj<big_endian>::as_arm_relobj(
5784           new_relaxed_sections[i]->relobj());
5785       unsigned int shndx = new_relaxed_sections[i]->shndx();
5786       // Tell Arm_relobj that this input section is converted.
5787       arm_relobj->convert_input_section_to_relaxed_section(shndx);
5788     }
5789 }
5790
5791 // Append non empty text sections in this to LIST in ascending
5792 // order of their position in this.
5793
5794 template<bool big_endian>
5795 void
5796 Arm_output_section<big_endian>::append_text_sections_to_list(
5797     Text_section_list* list)
5798 {
5799   gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5800
5801   for (Input_section_list::const_iterator p = this->input_sections().begin();
5802        p != this->input_sections().end();
5803        ++p)
5804     {
5805       // We only care about plain or relaxed input sections.  We also
5806       // ignore any merged sections.
5807       if (p->is_input_section() || p->is_relaxed_input_section())
5808         list->push_back(Text_section_list::value_type(p->relobj(),
5809                                                       p->shndx()));
5810     }
5811 }
5812
5813 template<bool big_endian>
5814 void
5815 Arm_output_section<big_endian>::fix_exidx_coverage(
5816     Layout* layout,
5817     const Text_section_list& sorted_text_sections,
5818     Symbol_table* symtab,
5819     bool merge_exidx_entries,
5820     const Task* task)
5821 {
5822   // We should only do this for the EXIDX output section.
5823   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5824
5825   // We don't want the relaxation loop to undo these changes, so we discard
5826   // the current saved states and take another one after the fix-up.
5827   this->discard_states();
5828
5829   // Remove all input sections.
5830   uint64_t address = this->address();
5831   typedef std::list<Output_section::Input_section> Input_section_list;
5832   Input_section_list input_sections;
5833   this->reset_address_and_file_offset();
5834   this->get_input_sections(address, std::string(""), &input_sections);
5835
5836   if (!this->input_sections().empty())
5837     gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5838
5839   // Go through all the known input sections and record them.
5840   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5841   typedef Unordered_map<Section_id, const Output_section::Input_section*,
5842                         Section_id_hash> Text_to_exidx_map;
5843   Text_to_exidx_map text_to_exidx_map;
5844   for (Input_section_list::const_iterator p = input_sections.begin();
5845        p != input_sections.end();
5846        ++p)
5847     {
5848       // This should never happen.  At this point, we should only see
5849       // plain EXIDX input sections.
5850       gold_assert(!p->is_relaxed_input_section());
5851       text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5852     }
5853
5854   Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5855
5856   // Go over the sorted text sections.
5857   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5858   Section_id_set processed_input_sections;
5859   for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5860        p != sorted_text_sections.end();
5861        ++p)
5862     {
5863       Relobj* relobj = p->first;
5864       unsigned int shndx = p->second;
5865
5866       Arm_relobj<big_endian>* arm_relobj =
5867          Arm_relobj<big_endian>::as_arm_relobj(relobj);
5868       const Arm_exidx_input_section* exidx_input_section =
5869          arm_relobj->exidx_input_section_by_link(shndx);
5870
5871       // If this text section has no EXIDX section or if the EXIDX section
5872       // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5873       // of the last seen EXIDX section.
5874       if (exidx_input_section == NULL || exidx_input_section->has_errors())
5875         {
5876           exidx_fixup.add_exidx_cantunwind_as_needed();
5877           continue;
5878         }
5879
5880       Relobj* exidx_relobj = exidx_input_section->relobj();
5881       unsigned int exidx_shndx = exidx_input_section->shndx();
5882       Section_id sid(exidx_relobj, exidx_shndx);
5883       Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5884       if (iter == text_to_exidx_map.end())
5885         {
5886           // This is odd.  We have not seen this EXIDX input section before.
5887           // We cannot do fix-up.  If we saw a SECTIONS clause in a script,
5888           // issue a warning instead.  We assume the user knows what he
5889           // or she is doing.  Otherwise, this is an error.
5890           if (layout->script_options()->saw_sections_clause())
5891             gold_warning(_("unwinding may not work because EXIDX input section"
5892                            " %u of %s is not in EXIDX output section"),
5893                          exidx_shndx, exidx_relobj->name().c_str());
5894           else
5895             gold_error(_("unwinding may not work because EXIDX input section"
5896                          " %u of %s is not in EXIDX output section"),
5897                        exidx_shndx, exidx_relobj->name().c_str());
5898
5899           exidx_fixup.add_exidx_cantunwind_as_needed();
5900           continue;
5901         }
5902
5903       // We need to access the contents of the EXIDX section, lock the
5904       // object here.
5905       Task_lock_obj<Object> tl(task, exidx_relobj);
5906       section_size_type exidx_size;
5907       const unsigned char* exidx_contents =
5908         exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5909
5910       // Fix up coverage and append input section to output data list.
5911       Arm_exidx_section_offset_map* section_offset_map = NULL;
5912       uint32_t deleted_bytes =
5913         exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5914                                                       exidx_contents,
5915                                                       exidx_size,
5916                                                       &section_offset_map);
5917
5918       if (deleted_bytes == exidx_input_section->size())
5919         {
5920           // The whole EXIDX section got merged.  Remove it from output.
5921           gold_assert(section_offset_map == NULL);
5922           exidx_relobj->set_output_section(exidx_shndx, NULL);
5923
5924           // All local symbols defined in this input section will be dropped.
5925           // We need to adjust output local symbol count.
5926           arm_relobj->set_output_local_symbol_count_needs_update();
5927         }
5928       else if (deleted_bytes > 0)
5929         {
5930           // Some entries are merged.  We need to convert this EXIDX input
5931           // section into a relaxed section.
5932           gold_assert(section_offset_map != NULL);
5933
5934           Arm_exidx_merged_section* merged_section =
5935             new Arm_exidx_merged_section(*exidx_input_section,
5936                                          *section_offset_map, deleted_bytes);
5937           merged_section->build_contents(exidx_contents, exidx_size);
5938
5939           const std::string secname = exidx_relobj->section_name(exidx_shndx);
5940           this->add_relaxed_input_section(layout, merged_section, secname);
5941           arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5942
5943           // All local symbols defined in discarded portions of this input
5944           // section will be dropped.  We need to adjust output local symbol
5945           // count.
5946           arm_relobj->set_output_local_symbol_count_needs_update();
5947         }
5948       else
5949         {
5950           // Just add back the EXIDX input section.
5951           gold_assert(section_offset_map == NULL);
5952           const Output_section::Input_section* pis = iter->second;
5953           gold_assert(pis->is_input_section());
5954           this->add_script_input_section(*pis);
5955         }
5956
5957       processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5958     }
5959
5960   // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5961   exidx_fixup.add_exidx_cantunwind_as_needed();
5962
5963   // Remove any known EXIDX input sections that are not processed.
5964   for (Input_section_list::const_iterator p = input_sections.begin();
5965        p != input_sections.end();
5966        ++p)
5967     {
5968       if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5969           == processed_input_sections.end())
5970         {
5971           // We discard a known EXIDX section because its linked
5972           // text section has been folded by ICF.  We also discard an
5973           // EXIDX section with error, the output does not matter in this
5974           // case.  We do this to avoid triggering asserts.
5975           Arm_relobj<big_endian>* arm_relobj =
5976             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5977           const Arm_exidx_input_section* exidx_input_section =
5978             arm_relobj->exidx_input_section_by_shndx(p->shndx());
5979           gold_assert(exidx_input_section != NULL);
5980           if (!exidx_input_section->has_errors())
5981             {
5982               unsigned int text_shndx = exidx_input_section->link();
5983               gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5984             }
5985
5986           // Remove this from link.  We also need to recount the
5987           // local symbols.
5988           p->relobj()->set_output_section(p->shndx(), NULL);
5989           arm_relobj->set_output_local_symbol_count_needs_update();
5990         }
5991     }
5992
5993   // Link exidx output section to the first seen output section and
5994   // set correct entry size.
5995   this->set_link_section(exidx_fixup.first_output_text_section());
5996   this->set_entsize(8);
5997
5998   // Make changes permanent.
5999   this->save_states();
6000   this->set_section_offsets_need_adjustment();
6001 }
6002
6003 // Link EXIDX output sections to text output sections.
6004
6005 template<bool big_endian>
6006 void
6007 Arm_output_section<big_endian>::set_exidx_section_link()
6008 {
6009   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
6010   if (!this->input_sections().empty())
6011     {
6012       Input_section_list::const_iterator p = this->input_sections().begin();
6013       Arm_relobj<big_endian>* arm_relobj =
6014         Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6015       unsigned exidx_shndx = p->shndx();
6016       const Arm_exidx_input_section* exidx_input_section =
6017         arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6018       gold_assert(exidx_input_section != NULL);
6019       unsigned int text_shndx = exidx_input_section->link();
6020       Output_section* os = arm_relobj->output_section(text_shndx);
6021       this->set_link_section(os);
6022     }
6023 }
6024
6025 // Arm_relobj methods.
6026
6027 // Determine if an input section is scannable for stub processing.  SHDR is
6028 // the header of the section and SHNDX is the section index.  OS is the output
6029 // section for the input section and SYMTAB is the global symbol table used to
6030 // look up ICF information.
6031
6032 template<bool big_endian>
6033 bool
6034 Arm_relobj<big_endian>::section_is_scannable(
6035     const elfcpp::Shdr<32, big_endian>& shdr,
6036     unsigned int shndx,
6037     const Output_section* os,
6038     const Symbol_table* symtab)
6039 {
6040   // Skip any empty sections, unallocated sections or sections whose
6041   // type are not SHT_PROGBITS.
6042   if (shdr.get_sh_size() == 0
6043       || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6044       || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6045     return false;
6046
6047   // Skip any discarded or ICF'ed sections.
6048   if (os == NULL || symtab->is_section_folded(this, shndx))
6049     return false;
6050
6051   // If this requires special offset handling, check to see if it is
6052   // a relaxed section.  If this is not, then it is a merged section that
6053   // we cannot handle.
6054   if (this->is_output_section_offset_invalid(shndx))
6055     {
6056       const Output_relaxed_input_section* poris =
6057         os->find_relaxed_input_section(this, shndx);
6058       if (poris == NULL)
6059         return false;
6060     }
6061
6062   return true;
6063 }
6064
6065 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6066 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6067
6068 template<bool big_endian>
6069 bool
6070 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6071     const elfcpp::Shdr<32, big_endian>& shdr,
6072     const Relobj::Output_sections& out_sections,
6073     const Symbol_table* symtab,
6074     const unsigned char* pshdrs)
6075 {
6076   unsigned int sh_type = shdr.get_sh_type();
6077   if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6078     return false;
6079
6080   // Ignore empty section.
6081   off_t sh_size = shdr.get_sh_size();
6082   if (sh_size == 0)
6083     return false;
6084
6085   // Ignore reloc section with unexpected symbol table.  The
6086   // error will be reported in the final link.
6087   if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6088     return false;
6089
6090   unsigned int reloc_size;
6091   if (sh_type == elfcpp::SHT_REL)
6092     reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6093   else
6094     reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6095
6096   // Ignore reloc section with unexpected entsize or uneven size.
6097   // The error will be reported in the final link.
6098   if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6099     return false;
6100
6101   // Ignore reloc section with bad info.  This error will be
6102   // reported in the final link.
6103   unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6104   if (index >= this->shnum())
6105     return false;
6106
6107   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6108   const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6109   return this->section_is_scannable(text_shdr, index,
6110                                    out_sections[index], symtab);
6111 }
6112
6113 // Return the output address of either a plain input section or a relaxed
6114 // input section.  SHNDX is the section index.  We define and use this
6115 // instead of calling Output_section::output_address because that is slow
6116 // for large output.
6117
6118 template<bool big_endian>
6119 Arm_address
6120 Arm_relobj<big_endian>::simple_input_section_output_address(
6121     unsigned int shndx,
6122     Output_section* os)
6123 {
6124   if (this->is_output_section_offset_invalid(shndx))
6125     {
6126       const Output_relaxed_input_section* poris =
6127         os->find_relaxed_input_section(this, shndx);
6128       // We do not handle merged sections here.
6129       gold_assert(poris != NULL);
6130       return poris->address();
6131     }
6132   else
6133     return os->address() + this->get_output_section_offset(shndx);
6134 }
6135
6136 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6137 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6138
6139 template<bool big_endian>
6140 bool
6141 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6142     const elfcpp::Shdr<32, big_endian>& shdr,
6143     unsigned int shndx,
6144     Output_section* os,
6145     const Symbol_table* symtab)
6146 {
6147   if (!this->section_is_scannable(shdr, shndx, os, symtab))
6148     return false;
6149
6150   // If the section does not cross any 4K-boundaries, it does not need to
6151   // be scanned.
6152   Arm_address address = this->simple_input_section_output_address(shndx, os);
6153   if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6154     return false;
6155
6156   return true;
6157 }
6158
6159 // Scan a section for Cortex-A8 workaround.
6160
6161 template<bool big_endian>
6162 void
6163 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6164     const elfcpp::Shdr<32, big_endian>& shdr,
6165     unsigned int shndx,
6166     Output_section* os,
6167     Target_arm<big_endian>* arm_target)
6168 {
6169   // Look for the first mapping symbol in this section.  It should be
6170   // at (shndx, 0).
6171   Mapping_symbol_position section_start(shndx, 0);
6172   typename Mapping_symbols_info::const_iterator p =
6173     this->mapping_symbols_info_.lower_bound(section_start);
6174
6175   // There are no mapping symbols for this section.  Treat it as a data-only
6176   // section.  Issue a warning if section is marked as containing
6177   // instructions.
6178   if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6179     {
6180       if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6181         gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6182                        "erratum because it has no mapping symbols."),
6183                      shndx, this->name().c_str());
6184       return;
6185     }
6186
6187   Arm_address output_address =
6188     this->simple_input_section_output_address(shndx, os);
6189
6190   // Get the section contents.
6191   section_size_type input_view_size = 0;
6192   const unsigned char* input_view =
6193     this->section_contents(shndx, &input_view_size, false);
6194
6195   // We need to go through the mapping symbols to determine what to
6196   // scan.  There are two reasons.  First, we should look at THUMB code and
6197   // THUMB code only.  Second, we only want to look at the 4K-page boundary
6198   // to speed up the scanning.
6199
6200   while (p != this->mapping_symbols_info_.end()
6201         && p->first.first == shndx)
6202     {
6203       typename Mapping_symbols_info::const_iterator next =
6204         this->mapping_symbols_info_.upper_bound(p->first);
6205
6206       // Only scan part of a section with THUMB code.
6207       if (p->second == 't')
6208         {
6209           // Determine the end of this range.
6210           section_size_type span_start =
6211             convert_to_section_size_type(p->first.second);
6212           section_size_type span_end;
6213           if (next != this->mapping_symbols_info_.end()
6214               && next->first.first == shndx)
6215             span_end = convert_to_section_size_type(next->first.second);
6216           else
6217             span_end = convert_to_section_size_type(shdr.get_sh_size());
6218
6219           if (((span_start + output_address) & ~0xfffUL)
6220               != ((span_end + output_address - 1) & ~0xfffUL))
6221             {
6222               arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6223                                                           span_start, span_end,
6224                                                           input_view,
6225                                                           output_address);
6226             }
6227         }
6228
6229       p = next;
6230     }
6231 }
6232
6233 // Scan relocations for stub generation.
6234
6235 template<bool big_endian>
6236 void
6237 Arm_relobj<big_endian>::scan_sections_for_stubs(
6238     Target_arm<big_endian>* arm_target,
6239     const Symbol_table* symtab,
6240     const Layout* layout)
6241 {
6242   unsigned int shnum = this->shnum();
6243   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6244
6245   // Read the section headers.
6246   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6247                                                shnum * shdr_size,
6248                                                true, true);
6249
6250   // To speed up processing, we set up hash tables for fast lookup of
6251   // input offsets to output addresses.
6252   this->initialize_input_to_output_maps();
6253
6254   const Relobj::Output_sections& out_sections(this->output_sections());
6255
6256   Relocate_info<32, big_endian> relinfo;
6257   relinfo.symtab = symtab;
6258   relinfo.layout = layout;
6259   relinfo.object = this;
6260
6261   // Do relocation stubs scanning.
6262   const unsigned char* p = pshdrs + shdr_size;
6263   for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6264     {
6265       const elfcpp::Shdr<32, big_endian> shdr(p);
6266       if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6267                                                   pshdrs))
6268         {
6269           unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6270           Arm_address output_offset = this->get_output_section_offset(index);
6271           Arm_address output_address;
6272           if (output_offset != invalid_address)
6273             output_address = out_sections[index]->address() + output_offset;
6274           else
6275             {
6276               // Currently this only happens for a relaxed section.
6277               const Output_relaxed_input_section* poris =
6278               out_sections[index]->find_relaxed_input_section(this, index);
6279               gold_assert(poris != NULL);
6280               output_address = poris->address();
6281             }
6282
6283           // Get the relocations.
6284           const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6285                                                         shdr.get_sh_size(),
6286                                                         true, false);
6287
6288           // Get the section contents.  This does work for the case in which
6289           // we modify the contents of an input section.  We need to pass the
6290           // output view under such circumstances.
6291           section_size_type input_view_size = 0;
6292           const unsigned char* input_view =
6293             this->section_contents(index, &input_view_size, false);
6294
6295           relinfo.reloc_shndx = i;
6296           relinfo.data_shndx = index;
6297           unsigned int sh_type = shdr.get_sh_type();
6298           unsigned int reloc_size;
6299           if (sh_type == elfcpp::SHT_REL)
6300             reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6301           else
6302             reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6303
6304           Output_section* os = out_sections[index];
6305           arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6306                                              shdr.get_sh_size() / reloc_size,
6307                                              os,
6308                                              output_offset == invalid_address,
6309                                              input_view, output_address,
6310                                              input_view_size);
6311         }
6312     }
6313
6314   // Do Cortex-A8 erratum stubs scanning.  This has to be done for a section
6315   // after its relocation section, if there is one, is processed for
6316   // relocation stubs.  Merging this loop with the one above would have been
6317   // complicated since we would have had to make sure that relocation stub
6318   // scanning is done first.
6319   if (arm_target->fix_cortex_a8())
6320     {
6321       const unsigned char* p = pshdrs + shdr_size;
6322       for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6323         {
6324           const elfcpp::Shdr<32, big_endian> shdr(p);
6325           if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6326                                                           out_sections[i],
6327                                                           symtab))
6328             this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6329                                                      arm_target);
6330         }
6331     }
6332
6333   // After we've done the relocations, we release the hash tables,
6334   // since we no longer need them.
6335   this->free_input_to_output_maps();
6336 }
6337
6338 // Count the local symbols.  The ARM backend needs to know if a symbol
6339 // is a THUMB function or not.  For global symbols, it is easy because
6340 // the Symbol object keeps the ELF symbol type.  For local symbol it is
6341 // harder because we cannot access this information.   So we override the
6342 // do_count_local_symbol in parent and scan local symbols to mark
6343 // THUMB functions.  This is not the most efficient way but I do not want to
6344 // slow down other ports by calling a per symbol target hook inside
6345 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6346
6347 template<bool big_endian>
6348 void
6349 Arm_relobj<big_endian>::do_count_local_symbols(
6350     Stringpool_template<char>* pool,
6351     Stringpool_template<char>* dynpool)
6352 {
6353   // We need to fix-up the values of any local symbols whose type are
6354   // STT_ARM_TFUNC.
6355
6356   // Ask parent to count the local symbols.
6357   Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6358   const unsigned int loccount = this->local_symbol_count();
6359   if (loccount == 0)
6360     return;
6361
6362   // Initialize the thumb function bit-vector.
6363   std::vector<bool> empty_vector(loccount, false);
6364   this->local_symbol_is_thumb_function_.swap(empty_vector);
6365
6366   // Read the symbol table section header.
6367   const unsigned int symtab_shndx = this->symtab_shndx();
6368   elfcpp::Shdr<32, big_endian>
6369       symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6370   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6371
6372   // Read the local symbols.
6373   const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6374   gold_assert(loccount == symtabshdr.get_sh_info());
6375   off_t locsize = loccount * sym_size;
6376   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6377                                               locsize, true, true);
6378
6379   // For mapping symbol processing, we need to read the symbol names.
6380   unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6381   if (strtab_shndx >= this->shnum())
6382     {
6383       this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6384       return;
6385     }
6386
6387   elfcpp::Shdr<32, big_endian>
6388     strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6389   if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6390     {
6391       this->error(_("symbol table name section has wrong type: %u"),
6392                   static_cast<unsigned int>(strtabshdr.get_sh_type()));
6393       return;
6394     }
6395   const char* pnames =
6396     reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6397                                                  strtabshdr.get_sh_size(),
6398                                                  false, false));
6399
6400   // Loop over the local symbols and mark any local symbols pointing
6401   // to THUMB functions.
6402
6403   // Skip the first dummy symbol.
6404   psyms += sym_size;
6405   typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6406     this->local_values();
6407   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6408     {
6409       elfcpp::Sym<32, big_endian> sym(psyms);
6410       elfcpp::STT st_type = sym.get_st_type();
6411       Symbol_value<32>& lv((*plocal_values)[i]);
6412       Arm_address input_value = lv.input_value();
6413
6414       // Check to see if this is a mapping symbol.
6415       const char* sym_name = pnames + sym.get_st_name();
6416       if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6417         {
6418           bool is_ordinary;
6419           unsigned int input_shndx =
6420             this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6421           gold_assert(is_ordinary);
6422
6423           // Strip of LSB in case this is a THUMB symbol.
6424           Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6425           this->mapping_symbols_info_[msp] = sym_name[1];
6426         }
6427
6428       if (st_type == elfcpp::STT_ARM_TFUNC
6429           || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6430         {
6431           // This is a THUMB function.  Mark this and canonicalize the
6432           // symbol value by setting LSB.
6433           this->local_symbol_is_thumb_function_[i] = true;
6434           if ((input_value & 1) == 0)
6435             lv.set_input_value(input_value | 1);
6436         }
6437     }
6438 }
6439
6440 // Relocate sections.
6441 template<bool big_endian>
6442 void
6443 Arm_relobj<big_endian>::do_relocate_sections(
6444     const Symbol_table* symtab,
6445     const Layout* layout,
6446     const unsigned char* pshdrs,
6447     Output_file* of,
6448     typename Sized_relobj_file<32, big_endian>::Views* pviews)
6449 {
6450   // Call parent to relocate sections.
6451   Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6452                                                           pshdrs, of, pviews);
6453
6454   // We do not generate stubs if doing a relocatable link.
6455   if (parameters->options().relocatable())
6456     return;
6457
6458   // Relocate stub tables.
6459   unsigned int shnum = this->shnum();
6460
6461   Target_arm<big_endian>* arm_target =
6462     Target_arm<big_endian>::default_target();
6463
6464   Relocate_info<32, big_endian> relinfo;
6465   relinfo.symtab = symtab;
6466   relinfo.layout = layout;
6467   relinfo.object = this;
6468
6469   for (unsigned int i = 1; i < shnum; ++i)
6470     {
6471       Arm_input_section<big_endian>* arm_input_section =
6472         arm_target->find_arm_input_section(this, i);
6473
6474       if (arm_input_section != NULL
6475           && arm_input_section->is_stub_table_owner()
6476           && !arm_input_section->stub_table()->empty())
6477         {
6478           // We cannot discard a section if it owns a stub table.
6479           Output_section* os = this->output_section(i);
6480           gold_assert(os != NULL);
6481
6482           relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6483           relinfo.reloc_shdr = NULL;
6484           relinfo.data_shndx = i;
6485           relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6486
6487           gold_assert((*pviews)[i].view != NULL);
6488
6489           // We are passed the output section view.  Adjust it to cover the
6490           // stub table only.
6491           Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6492           gold_assert((stub_table->address() >= (*pviews)[i].address)
6493                       && ((stub_table->address() + stub_table->data_size())
6494                           <= (*pviews)[i].address + (*pviews)[i].view_size));
6495
6496           off_t offset = stub_table->address() - (*pviews)[i].address;
6497           unsigned char* view = (*pviews)[i].view + offset;
6498           Arm_address address = stub_table->address();
6499           section_size_type view_size = stub_table->data_size();
6500
6501           stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6502                                      view_size);
6503         }
6504
6505       // Apply Cortex A8 workaround if applicable.
6506       if (this->section_has_cortex_a8_workaround(i))
6507         {
6508           unsigned char* view = (*pviews)[i].view;
6509           Arm_address view_address = (*pviews)[i].address;
6510           section_size_type view_size = (*pviews)[i].view_size;
6511           Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6512
6513           // Adjust view to cover section.
6514           Output_section* os = this->output_section(i);
6515           gold_assert(os != NULL);
6516           Arm_address section_address =
6517             this->simple_input_section_output_address(i, os);
6518           uint64_t section_size = this->section_size(i);
6519
6520           gold_assert(section_address >= view_address
6521                       && ((section_address + section_size)
6522                           <= (view_address + view_size)));
6523
6524           unsigned char* section_view = view + (section_address - view_address);
6525
6526           // Apply the Cortex-A8 workaround to the output address range
6527           // corresponding to this input section.
6528           stub_table->apply_cortex_a8_workaround_to_address_range(
6529               arm_target,
6530               section_view,
6531               section_address,
6532               section_size);
6533         }
6534     }
6535 }
6536
6537 // Find the linked text section of an EXIDX section by looking at the first
6538 // relocation.  4.4.1 of the EHABI specifications says that an EXIDX section
6539 // must be linked to its associated code section via the sh_link field of
6540 // its section header.  However, some tools are broken and the link is not
6541 // always set.  LD just drops such an EXIDX section silently, causing the
6542 // associated code not unwindabled.   Here we try a little bit harder to
6543 // discover the linked code section.
6544 //
6545 // PSHDR points to the section header of a relocation section of an EXIDX
6546 // section.  If we can find a linked text section, return true and
6547 // store the text section index in the location PSHNDX.  Otherwise
6548 // return false.
6549
6550 template<bool big_endian>
6551 bool
6552 Arm_relobj<big_endian>::find_linked_text_section(
6553     const unsigned char* pshdr,
6554     const unsigned char* psyms,
6555     unsigned int* pshndx)
6556 {
6557   elfcpp::Shdr<32, big_endian> shdr(pshdr);
6558
6559   // If there is no relocation, we cannot find the linked text section.
6560   size_t reloc_size;
6561   if (shdr.get_sh_type() == elfcpp::SHT_REL)
6562       reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6563   else
6564       reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6565   size_t reloc_count = shdr.get_sh_size() / reloc_size;
6566
6567   // Get the relocations.
6568   const unsigned char* prelocs =
6569       this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6570
6571   // Find the REL31 relocation for the first word of the first EXIDX entry.
6572   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6573     {
6574       Arm_address r_offset;
6575       typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6576       if (shdr.get_sh_type() == elfcpp::SHT_REL)
6577         {
6578           typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6579           r_info = reloc.get_r_info();
6580           r_offset = reloc.get_r_offset();
6581         }
6582       else
6583         {
6584           typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6585           r_info = reloc.get_r_info();
6586           r_offset = reloc.get_r_offset();
6587         }
6588
6589       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6590       if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6591         continue;
6592
6593       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6594       if (r_sym == 0
6595           || r_sym >= this->local_symbol_count()
6596           || r_offset != 0)
6597         continue;
6598
6599       // This is the relocation for the first word of the first EXIDX entry.
6600       // We expect to see a local section symbol.
6601       const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6602       elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6603       if (sym.get_st_type() == elfcpp::STT_SECTION)
6604         {
6605           bool is_ordinary;
6606           *pshndx =
6607             this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6608           gold_assert(is_ordinary);
6609           return true;
6610         }
6611       else
6612         return false;
6613     }
6614
6615   return false;
6616 }
6617
6618 // Make an EXIDX input section object for an EXIDX section whose index is
6619 // SHNDX.  SHDR is the section header of the EXIDX section and TEXT_SHNDX
6620 // is the section index of the linked text section.
6621
6622 template<bool big_endian>
6623 void
6624 Arm_relobj<big_endian>::make_exidx_input_section(
6625     unsigned int shndx,
6626     const elfcpp::Shdr<32, big_endian>& shdr,
6627     unsigned int text_shndx,
6628     const elfcpp::Shdr<32, big_endian>& text_shdr)
6629 {
6630   // Create an Arm_exidx_input_section object for this EXIDX section.
6631   Arm_exidx_input_section* exidx_input_section =
6632     new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6633                                 shdr.get_sh_addralign(),
6634                                 text_shdr.get_sh_size());
6635
6636   gold_assert(this->exidx_section_map_[shndx] == NULL);
6637   this->exidx_section_map_[shndx] = exidx_input_section;
6638
6639   if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6640     {
6641       gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6642                  this->section_name(shndx).c_str(), shndx, text_shndx,
6643                  this->name().c_str());
6644       exidx_input_section->set_has_errors();
6645     }
6646   else if (this->exidx_section_map_[text_shndx] != NULL)
6647     {
6648       unsigned other_exidx_shndx =
6649         this->exidx_section_map_[text_shndx]->shndx();
6650       gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6651                    "%s(%u) in %s"),
6652                  this->section_name(shndx).c_str(), shndx,
6653                  this->section_name(other_exidx_shndx).c_str(),
6654                  other_exidx_shndx, this->section_name(text_shndx).c_str(),
6655                  text_shndx, this->name().c_str());
6656       exidx_input_section->set_has_errors();
6657     }
6658   else
6659      this->exidx_section_map_[text_shndx] = exidx_input_section;
6660
6661   // Check section flags of text section.
6662   if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6663     {
6664       gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6665                    " in %s"),
6666                  this->section_name(shndx).c_str(), shndx,
6667                  this->section_name(text_shndx).c_str(), text_shndx,
6668                  this->name().c_str());
6669       exidx_input_section->set_has_errors();
6670     }
6671   else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6672     // I would like to make this an error but currently ld just ignores
6673     // this.
6674     gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6675                    "%s(%u) in %s"),
6676                  this->section_name(shndx).c_str(), shndx,
6677                  this->section_name(text_shndx).c_str(), text_shndx,
6678                  this->name().c_str());
6679 }
6680
6681 // Read the symbol information.
6682
6683 template<bool big_endian>
6684 void
6685 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6686 {
6687   // Call parent class to read symbol information.
6688   Sized_relobj_file<32, big_endian>::do_read_symbols(sd);
6689
6690   // If this input file is a binary file, it has no processor
6691   // specific flags and attributes section.
6692   Input_file::Format format = this->input_file()->format();
6693   if (format != Input_file::FORMAT_ELF)
6694     {
6695       gold_assert(format == Input_file::FORMAT_BINARY);
6696       this->merge_flags_and_attributes_ = false;
6697       return;
6698     }
6699
6700   // Read processor-specific flags in ELF file header.
6701   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6702                                               elfcpp::Elf_sizes<32>::ehdr_size,
6703                                               true, false);
6704   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6705   this->processor_specific_flags_ = ehdr.get_e_flags();
6706
6707   // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6708   // sections.
6709   std::vector<unsigned int> deferred_exidx_sections;
6710   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6711   const unsigned char* pshdrs = sd->section_headers->data();
6712   const unsigned char* ps = pshdrs + shdr_size;
6713   bool must_merge_flags_and_attributes = false;
6714   for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6715     {
6716       elfcpp::Shdr<32, big_endian> shdr(ps);
6717
6718       // Sometimes an object has no contents except the section name string
6719       // table and an empty symbol table with the undefined symbol.  We
6720       // don't want to merge processor-specific flags from such an object.
6721       if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6722         {
6723           // Symbol table is not empty.
6724           const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6725              elfcpp::Elf_sizes<32>::sym_size;
6726           if (shdr.get_sh_size() > sym_size)
6727             must_merge_flags_and_attributes = true;
6728         }
6729       else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6730         // If this is neither an empty symbol table nor a string table,
6731         // be conservative.
6732         must_merge_flags_and_attributes = true;
6733
6734       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6735         {
6736           gold_assert(this->attributes_section_data_ == NULL);
6737           section_offset_type section_offset = shdr.get_sh_offset();
6738           section_size_type section_size =
6739             convert_to_section_size_type(shdr.get_sh_size());
6740           const unsigned char* view =
6741              this->get_view(section_offset, section_size, true, false);
6742           this->attributes_section_data_ =
6743             new Attributes_section_data(view, section_size);
6744         }
6745       else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6746         {
6747           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6748           if (text_shndx == elfcpp::SHN_UNDEF)
6749             deferred_exidx_sections.push_back(i);
6750           else
6751             {
6752               elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6753                                                      + text_shndx * shdr_size);
6754               this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6755             }
6756           // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6757           if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6758             gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6759                          this->section_name(i).c_str(), this->name().c_str());
6760         }
6761     }
6762
6763   // This is rare.
6764   if (!must_merge_flags_and_attributes)
6765     {
6766       gold_assert(deferred_exidx_sections.empty());
6767       this->merge_flags_and_attributes_ = false;
6768       return;
6769     }
6770
6771   // Some tools are broken and they do not set the link of EXIDX sections.
6772   // We look at the first relocation to figure out the linked sections.
6773   if (!deferred_exidx_sections.empty())
6774     {
6775       // We need to go over the section headers again to find the mapping
6776       // from sections being relocated to their relocation sections.  This is
6777       // a bit inefficient as we could do that in the loop above.  However,
6778       // we do not expect any deferred EXIDX sections normally.  So we do not
6779       // want to slow down the most common path.
6780       typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6781       Reloc_map reloc_map;
6782       ps = pshdrs + shdr_size;
6783       for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6784         {
6785           elfcpp::Shdr<32, big_endian> shdr(ps);
6786           elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6787           if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6788             {
6789               unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6790               if (info_shndx >= this->shnum())
6791                 gold_error(_("relocation section %u has invalid info %u"),
6792                            i, info_shndx);
6793               Reloc_map::value_type value(info_shndx, i);
6794               std::pair<Reloc_map::iterator, bool> result =
6795                 reloc_map.insert(value);
6796               if (!result.second)
6797                 gold_error(_("section %u has multiple relocation sections "
6798                              "%u and %u"),
6799                            info_shndx, i, reloc_map[info_shndx]);
6800             }
6801         }
6802
6803       // Read the symbol table section header.
6804       const unsigned int symtab_shndx = this->symtab_shndx();
6805       elfcpp::Shdr<32, big_endian>
6806           symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6807       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6808
6809       // Read the local symbols.
6810       const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6811       const unsigned int loccount = this->local_symbol_count();
6812       gold_assert(loccount == symtabshdr.get_sh_info());
6813       off_t locsize = loccount * sym_size;
6814       const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6815                                                   locsize, true, true);
6816
6817       // Process the deferred EXIDX sections.
6818       for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6819         {
6820           unsigned int shndx = deferred_exidx_sections[i];
6821           elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6822           unsigned int text_shndx = elfcpp::SHN_UNDEF;
6823           Reloc_map::const_iterator it = reloc_map.find(shndx);
6824           if (it != reloc_map.end())
6825             find_linked_text_section(pshdrs + it->second * shdr_size,
6826                                      psyms, &text_shndx);
6827           elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6828                                                  + text_shndx * shdr_size);
6829           this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6830         }
6831     }
6832 }
6833
6834 // Process relocations for garbage collection.  The ARM target uses .ARM.exidx
6835 // sections for unwinding.  These sections are referenced implicitly by
6836 // text sections linked in the section headers.  If we ignore these implicit
6837 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6838 // will be garbage-collected incorrectly.  Hence we override the same function
6839 // in the base class to handle these implicit references.
6840
6841 template<bool big_endian>
6842 void
6843 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6844                                              Layout* layout,
6845                                              Read_relocs_data* rd)
6846 {
6847   // First, call base class method to process relocations in this object.
6848   Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6849
6850   // If --gc-sections is not specified, there is nothing more to do.
6851   // This happens when --icf is used but --gc-sections is not.
6852   if (!parameters->options().gc_sections())
6853     return;
6854
6855   unsigned int shnum = this->shnum();
6856   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6857   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6858                                                shnum * shdr_size,
6859                                                true, true);
6860
6861   // Scan section headers for sections of type SHT_ARM_EXIDX.  Add references
6862   // to these from the linked text sections.
6863   const unsigned char* ps = pshdrs + shdr_size;
6864   for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6865     {
6866       elfcpp::Shdr<32, big_endian> shdr(ps);
6867       if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6868         {
6869           // Found an .ARM.exidx section, add it to the set of reachable
6870           // sections from its linked text section.
6871           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6872           symtab->gc()->add_reference(this, text_shndx, this, i);
6873         }
6874     }
6875 }
6876
6877 // Update output local symbol count.  Owing to EXIDX entry merging, some local
6878 // symbols  will be removed in output.  Adjust output local symbol count
6879 // accordingly.  We can only changed the static output local symbol count.  It
6880 // is too late to change the dynamic symbols.
6881
6882 template<bool big_endian>
6883 void
6884 Arm_relobj<big_endian>::update_output_local_symbol_count()
6885 {
6886   // Caller should check that this needs updating.  We want caller checking
6887   // because output_local_symbol_count_needs_update() is most likely inlined.
6888   gold_assert(this->output_local_symbol_count_needs_update_);
6889
6890   gold_assert(this->symtab_shndx() != -1U);
6891   if (this->symtab_shndx() == 0)
6892     {
6893       // This object has no symbols.  Weird but legal.
6894       return;
6895     }
6896
6897   // Read the symbol table section header.
6898   const unsigned int symtab_shndx = this->symtab_shndx();
6899   elfcpp::Shdr<32, big_endian>
6900     symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6901   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6902
6903   // Read the local symbols.
6904   const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6905   const unsigned int loccount = this->local_symbol_count();
6906   gold_assert(loccount == symtabshdr.get_sh_info());
6907   off_t locsize = loccount * sym_size;
6908   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6909                                               locsize, true, true);
6910
6911   // Loop over the local symbols.
6912
6913   typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6914      Output_sections;
6915   const Output_sections& out_sections(this->output_sections());
6916   unsigned int shnum = this->shnum();
6917   unsigned int count = 0;
6918   // Skip the first, dummy, symbol.
6919   psyms += sym_size;
6920   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6921     {
6922       elfcpp::Sym<32, big_endian> sym(psyms);
6923
6924       Symbol_value<32>& lv((*this->local_values())[i]);
6925
6926       // This local symbol was already discarded by do_count_local_symbols.
6927       if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6928         continue;
6929
6930       bool is_ordinary;
6931       unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6932                                                   &is_ordinary);
6933
6934       if (shndx < shnum)
6935         {
6936           Output_section* os = out_sections[shndx];
6937
6938           // This local symbol no longer has an output section.  Discard it.
6939           if (os == NULL)
6940             {
6941               lv.set_no_output_symtab_entry();
6942               continue;
6943             }
6944
6945           // Currently we only discard parts of EXIDX input sections.
6946           // We explicitly check for a merged EXIDX input section to avoid
6947           // calling Output_section_data::output_offset unless necessary.
6948           if ((this->get_output_section_offset(shndx) == invalid_address)
6949               && (this->exidx_input_section_by_shndx(shndx) != NULL))
6950             {
6951               section_offset_type output_offset =
6952                 os->output_offset(this, shndx, lv.input_value());
6953               if (output_offset == -1)
6954                 {
6955                   // This symbol is defined in a part of an EXIDX input section
6956                   // that is discarded due to entry merging.
6957                   lv.set_no_output_symtab_entry();
6958                   continue;
6959                 }
6960             }
6961         }
6962
6963       ++count;
6964     }
6965
6966   this->set_output_local_symbol_count(count);
6967   this->output_local_symbol_count_needs_update_ = false;
6968 }
6969
6970 // Arm_dynobj methods.
6971
6972 // Read the symbol information.
6973
6974 template<bool big_endian>
6975 void
6976 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6977 {
6978   // Call parent class to read symbol information.
6979   Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6980
6981   // Read processor-specific flags in ELF file header.
6982   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6983                                               elfcpp::Elf_sizes<32>::ehdr_size,
6984                                               true, false);
6985   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6986   this->processor_specific_flags_ = ehdr.get_e_flags();
6987
6988   // Read the attributes section if there is one.
6989   // We read from the end because gas seems to put it near the end of
6990   // the section headers.
6991   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6992   const unsigned char* ps =
6993     sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6994   for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6995     {
6996       elfcpp::Shdr<32, big_endian> shdr(ps);
6997       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6998         {
6999           section_offset_type section_offset = shdr.get_sh_offset();
7000           section_size_type section_size =
7001             convert_to_section_size_type(shdr.get_sh_size());
7002           const unsigned char* view =
7003             this->get_view(section_offset, section_size, true, false);
7004           this->attributes_section_data_ =
7005             new Attributes_section_data(view, section_size);
7006           break;
7007         }
7008     }
7009 }
7010
7011 // Stub_addend_reader methods.
7012
7013 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7014
7015 template<bool big_endian>
7016 elfcpp::Elf_types<32>::Elf_Swxword
7017 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7018     unsigned int r_type,
7019     const unsigned char* view,
7020     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7021 {
7022   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
7023
7024   switch (r_type)
7025     {
7026     case elfcpp::R_ARM_CALL:
7027     case elfcpp::R_ARM_JUMP24:
7028     case elfcpp::R_ARM_PLT32:
7029       {
7030         typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7031         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7032         Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7033         return Bits<26>::sign_extend32(val << 2);
7034       }
7035
7036     case elfcpp::R_ARM_THM_CALL:
7037     case elfcpp::R_ARM_THM_JUMP24:
7038     case elfcpp::R_ARM_THM_XPC22:
7039       {
7040         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7041         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7042         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7043         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7044         return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7045       }
7046
7047     case elfcpp::R_ARM_THM_JUMP19:
7048       {
7049         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7050         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7051         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7052         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7053         return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7054       }
7055
7056     default:
7057       gold_unreachable();
7058     }
7059 }
7060
7061 // Arm_output_data_got methods.
7062
7063 // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
7064 // The first one is initialized to be 1, which is the module index for
7065 // the main executable and the second one 0.  A reloc of the type
7066 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7067 // be applied by gold.  GSYM is a global symbol.
7068 //
7069 template<bool big_endian>
7070 void
7071 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7072     unsigned int got_type,
7073     Symbol* gsym)
7074 {
7075   if (gsym->has_got_offset(got_type))
7076     return;
7077
7078   // We are doing a static link.  Just mark it as belong to module 1,
7079   // the executable.
7080   unsigned int got_offset = this->add_constant(1);
7081   gsym->set_got_offset(got_type, got_offset);
7082   got_offset = this->add_constant(0);
7083   this->static_relocs_.push_back(Static_reloc(got_offset,
7084                                               elfcpp::R_ARM_TLS_DTPOFF32,
7085                                               gsym));
7086 }
7087
7088 // Same as the above but for a local symbol.
7089
7090 template<bool big_endian>
7091 void
7092 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7093   unsigned int got_type,
7094   Sized_relobj_file<32, big_endian>* object,
7095   unsigned int index)
7096 {
7097   if (object->local_has_got_offset(index, got_type))
7098     return;
7099
7100   // We are doing a static link.  Just mark it as belong to module 1,
7101   // the executable.
7102   unsigned int got_offset = this->add_constant(1);
7103   object->set_local_got_offset(index, got_type, got_offset);
7104   got_offset = this->add_constant(0);
7105   this->static_relocs_.push_back(Static_reloc(got_offset,
7106                                               elfcpp::R_ARM_TLS_DTPOFF32,
7107                                               object, index));
7108 }
7109
7110 template<bool big_endian>
7111 void
7112 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7113 {
7114   // Call parent to write out GOT.
7115   Output_data_got<32, big_endian>::do_write(of);
7116
7117   // We are done if there is no fix up.
7118   if (this->static_relocs_.empty())
7119     return;
7120
7121   gold_assert(parameters->doing_static_link());
7122
7123   const off_t offset = this->offset();
7124   const section_size_type oview_size =
7125     convert_to_section_size_type(this->data_size());
7126   unsigned char* const oview = of->get_output_view(offset, oview_size);
7127
7128   Output_segment* tls_segment = this->layout_->tls_segment();
7129   gold_assert(tls_segment != NULL);
7130
7131   // The thread pointer $tp points to the TCB, which is followed by the
7132   // TLS.  So we need to adjust $tp relative addressing by this amount.
7133   Arm_address aligned_tcb_size =
7134     align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7135
7136   for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7137     {
7138       Static_reloc& reloc(this->static_relocs_[i]);
7139
7140       Arm_address value;
7141       if (!reloc.symbol_is_global())
7142         {
7143           Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7144           const Symbol_value<32>* psymval =
7145             reloc.relobj()->local_symbol(reloc.index());
7146
7147           // We are doing static linking.  Issue an error and skip this
7148           // relocation if the symbol is undefined or in a discarded_section.
7149           bool is_ordinary;
7150           unsigned int shndx = psymval->input_shndx(&is_ordinary);
7151           if ((shndx == elfcpp::SHN_UNDEF)
7152               || (is_ordinary
7153                   && shndx != elfcpp::SHN_UNDEF
7154                   && !object->is_section_included(shndx)
7155                   && !this->symbol_table_->is_section_folded(object, shndx)))
7156             {
7157               gold_error(_("undefined or discarded local symbol %u from "
7158                            " object %s in GOT"),
7159                          reloc.index(), reloc.relobj()->name().c_str());
7160               continue;
7161             }
7162
7163           value = psymval->value(object, 0);
7164         }
7165       else
7166         {
7167           const Symbol* gsym = reloc.symbol();
7168           gold_assert(gsym != NULL);
7169           if (gsym->is_forwarder())
7170             gsym = this->symbol_table_->resolve_forwards(gsym);
7171
7172           // We are doing static linking.  Issue an error and skip this
7173           // relocation if the symbol is undefined or in a discarded_section
7174           // unless it is a weakly_undefined symbol.
7175           if ((gsym->is_defined_in_discarded_section()
7176                || gsym->is_undefined())
7177               && !gsym->is_weak_undefined())
7178             {
7179               gold_error(_("undefined or discarded symbol %s in GOT"),
7180                          gsym->name());
7181               continue;
7182             }
7183
7184           if (!gsym->is_weak_undefined())
7185             {
7186               const Sized_symbol<32>* sym =
7187                 static_cast<const Sized_symbol<32>*>(gsym);
7188               value = sym->value();
7189             }
7190           else
7191               value = 0;
7192         }
7193
7194       unsigned got_offset = reloc.got_offset();
7195       gold_assert(got_offset < oview_size);
7196
7197       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7198       Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7199       Valtype x;
7200       switch (reloc.r_type())
7201         {
7202         case elfcpp::R_ARM_TLS_DTPOFF32:
7203           x = value;
7204           break;
7205         case elfcpp::R_ARM_TLS_TPOFF32:
7206           x = value + aligned_tcb_size;
7207           break;
7208         default:
7209           gold_unreachable();
7210         }
7211       elfcpp::Swap<32, big_endian>::writeval(wv, x);
7212     }
7213
7214   of->write_output_view(offset, oview_size, oview);
7215 }
7216
7217 // A class to handle the PLT data.
7218 // This is an abstract base class that handles most of the linker details
7219 // but does not know the actual contents of PLT entries.  The derived
7220 // classes below fill in those details.
7221
7222 template<bool big_endian>
7223 class Output_data_plt_arm : public Output_section_data
7224 {
7225  public:
7226   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7227     Reloc_section;
7228
7229   Output_data_plt_arm(Layout*, uint64_t addralign, Output_data_space*);
7230
7231   // Add an entry to the PLT.
7232   void
7233   add_entry(Symbol* gsym);
7234
7235   // Return the .rel.plt section data.
7236   const Reloc_section*
7237   rel_plt() const
7238   { return this->rel_; }
7239
7240   // Return the number of PLT entries.
7241   unsigned int
7242   entry_count() const
7243   { return this->count_; }
7244
7245   // Return the offset of the first non-reserved PLT entry.
7246   unsigned int
7247   first_plt_entry_offset() const
7248   { return this->do_first_plt_entry_offset(); }
7249
7250   // Return the size of a PLT entry.
7251   unsigned int
7252   get_plt_entry_size() const
7253   { return this->do_get_plt_entry_size(); }
7254
7255  protected:
7256   // Fill in the first PLT entry.
7257   void
7258   fill_first_plt_entry(unsigned char* pov,
7259                        Arm_address got_address,
7260                        Arm_address plt_address)
7261   { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
7262
7263   void
7264   fill_plt_entry(unsigned char* pov,
7265                  Arm_address got_address,
7266                  Arm_address plt_address,
7267                  unsigned int got_offset,
7268                  unsigned int plt_offset)
7269   { do_fill_plt_entry(pov, got_address, plt_address, got_offset, plt_offset); }
7270
7271   virtual unsigned int
7272   do_first_plt_entry_offset() const = 0;
7273
7274   virtual unsigned int
7275   do_get_plt_entry_size() const = 0;
7276
7277   virtual void
7278   do_fill_first_plt_entry(unsigned char* pov,
7279                           Arm_address got_address,
7280                           Arm_address plt_address) = 0;
7281
7282   virtual void
7283   do_fill_plt_entry(unsigned char* pov,
7284                     Arm_address got_address,
7285                     Arm_address plt_address,
7286                     unsigned int got_offset,
7287                     unsigned int plt_offset) = 0;
7288
7289   void
7290   do_adjust_output_section(Output_section* os);
7291
7292   // Write to a map file.
7293   void
7294   do_print_to_mapfile(Mapfile* mapfile) const
7295   { mapfile->print_output_data(this, _("** PLT")); }
7296
7297  private:
7298   // Set the final size.
7299   void
7300   set_final_data_size()
7301   {
7302     this->set_data_size(this->first_plt_entry_offset()
7303                         + this->count_ * this->get_plt_entry_size());
7304   }
7305
7306   // Write out the PLT data.
7307   void
7308   do_write(Output_file*);
7309
7310   // The reloc section.
7311   Reloc_section* rel_;
7312   // The .got.plt section.
7313   Output_data_space* got_plt_;
7314   // The number of PLT entries.
7315   unsigned int count_;
7316 };
7317
7318 // Create the PLT section.  The ordinary .got section is an argument,
7319 // since we need to refer to the start.  We also create our own .got
7320 // section just for PLT entries.
7321
7322 template<bool big_endian>
7323 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7324                                                      uint64_t addralign,
7325                                                      Output_data_space* got_plt)
7326   : Output_section_data(addralign), got_plt_(got_plt), count_(0)
7327 {
7328   this->rel_ = new Reloc_section(false);
7329   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7330                                   elfcpp::SHF_ALLOC, this->rel_,
7331                                   ORDER_DYNAMIC_PLT_RELOCS, false);
7332 }
7333
7334 template<bool big_endian>
7335 void
7336 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7337 {
7338   os->set_entsize(0);
7339 }
7340
7341 // Add an entry to the PLT.
7342
7343 template<bool big_endian>
7344 void
7345 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7346 {
7347   gold_assert(!gsym->has_plt_offset());
7348
7349   // Note that when setting the PLT offset we skip the initial
7350   // reserved PLT entry.
7351   gsym->set_plt_offset((this->count_) * this->get_plt_entry_size()
7352                        + this->first_plt_entry_offset());
7353
7354   ++this->count_;
7355
7356   section_offset_type got_offset = this->got_plt_->current_data_size();
7357
7358   // Every PLT entry needs a GOT entry which points back to the PLT
7359   // entry (this will be changed by the dynamic linker, normally
7360   // lazily when the function is called).
7361   this->got_plt_->set_current_data_size(got_offset + 4);
7362
7363   // Every PLT entry needs a reloc.
7364   gsym->set_needs_dynsym_entry();
7365   this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7366                          got_offset);
7367
7368   // Note that we don't need to save the symbol.  The contents of the
7369   // PLT are independent of which symbols are used.  The symbols only
7370   // appear in the relocations.
7371 }
7372
7373 template<bool big_endian>
7374 class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
7375 {
7376  public:
7377   Output_data_plt_arm_standard(Layout* layout, Output_data_space* got_plt)
7378     : Output_data_plt_arm<big_endian>(layout, 4, got_plt)
7379   { }
7380
7381  protected:
7382   // Return the offset of the first non-reserved PLT entry.
7383   virtual unsigned int
7384   do_first_plt_entry_offset() const
7385   { return sizeof(first_plt_entry); }
7386
7387   // Return the size of a PLT entry.
7388   virtual unsigned int
7389   do_get_plt_entry_size() const
7390   { return sizeof(plt_entry); }
7391
7392   virtual void
7393   do_fill_first_plt_entry(unsigned char* pov,
7394                           Arm_address got_address,
7395                           Arm_address plt_address);
7396
7397   virtual void
7398   do_fill_plt_entry(unsigned char* pov,
7399                     Arm_address got_address,
7400                     Arm_address plt_address,
7401                     unsigned int got_offset,
7402                     unsigned int plt_offset);
7403
7404  private:
7405   // Template for the first PLT entry.
7406   static const uint32_t first_plt_entry[5];
7407
7408   // Template for subsequent PLT entries.
7409   static const uint32_t plt_entry[3];
7410 };
7411
7412 // ARM PLTs.
7413 // FIXME:  This is not very flexible.  Right now this has only been tested
7414 // on armv5te.  If we are to support additional architecture features like
7415 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7416
7417 // The first entry in the PLT.
7418 template<bool big_endian>
7419 const uint32_t Output_data_plt_arm_standard<big_endian>::first_plt_entry[5] =
7420 {
7421   0xe52de004,   // str   lr, [sp, #-4]!
7422   0xe59fe004,   // ldr   lr, [pc, #4]
7423   0xe08fe00e,   // add   lr, pc, lr
7424   0xe5bef008,   // ldr   pc, [lr, #8]!
7425   0x00000000,   // &GOT[0] - .
7426 };
7427
7428 template<bool big_endian>
7429 void
7430 Output_data_plt_arm_standard<big_endian>::do_fill_first_plt_entry(
7431     unsigned char* pov,
7432     Arm_address got_address,
7433     Arm_address plt_address)
7434 {
7435   // Write first PLT entry.  All but the last word are constants.
7436   const size_t num_first_plt_words = (sizeof(first_plt_entry)
7437                                       / sizeof(plt_entry[0]));
7438   for (size_t i = 0; i < num_first_plt_words - 1; i++)
7439     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7440   // Last word in first PLT entry is &GOT[0] - .
7441   elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7442                                          got_address - (plt_address + 16));
7443 }
7444
7445 // Subsequent entries in the PLT.
7446
7447 template<bool big_endian>
7448 const uint32_t Output_data_plt_arm_standard<big_endian>::plt_entry[3] =
7449 {
7450   0xe28fc600,   // add   ip, pc, #0xNN00000
7451   0xe28cca00,   // add   ip, ip, #0xNN000
7452   0xe5bcf000,   // ldr   pc, [ip, #0xNNN]!
7453 };
7454
7455 template<bool big_endian>
7456 void
7457 Output_data_plt_arm_standard<big_endian>::do_fill_plt_entry(
7458     unsigned char* pov,
7459     Arm_address got_address,
7460     Arm_address plt_address,
7461     unsigned int got_offset,
7462     unsigned int plt_offset)
7463 {
7464   int32_t offset = ((got_address + got_offset)
7465                     - (plt_address + plt_offset + 8));
7466
7467   gold_assert(offset >= 0 && offset < 0x0fffffff);
7468   uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7469   elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7470   uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7471   elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7472   uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7473   elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7474 }
7475
7476 // Write out the PLT.  This uses the hand-coded instructions above,
7477 // and adjusts them as needed.  This is all specified by the arm ELF
7478 // Processor Supplement.
7479
7480 template<bool big_endian>
7481 void
7482 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7483 {
7484   const off_t offset = this->offset();
7485   const section_size_type oview_size =
7486     convert_to_section_size_type(this->data_size());
7487   unsigned char* const oview = of->get_output_view(offset, oview_size);
7488
7489   const off_t got_file_offset = this->got_plt_->offset();
7490   const section_size_type got_size =
7491     convert_to_section_size_type(this->got_plt_->data_size());
7492   unsigned char* const got_view = of->get_output_view(got_file_offset,
7493                                                       got_size);
7494   unsigned char* pov = oview;
7495
7496   Arm_address plt_address = this->address();
7497   Arm_address got_address = this->got_plt_->address();
7498
7499   // Write first PLT entry.
7500   this->fill_first_plt_entry(pov, got_address, plt_address);
7501   pov += this->first_plt_entry_offset();
7502
7503   unsigned char* got_pov = got_view;
7504
7505   memset(got_pov, 0, 12);
7506   got_pov += 12;
7507
7508   unsigned int plt_offset = this->first_plt_entry_offset();
7509   unsigned int got_offset = 12;
7510   const unsigned int count = this->count_;
7511   for (unsigned int i = 0;
7512        i < count;
7513        ++i,
7514          pov += this->get_plt_entry_size(),
7515          got_pov += 4,
7516          plt_offset += this->get_plt_entry_size(),
7517          got_offset += 4)
7518     {
7519       // Set and adjust the PLT entry itself.
7520       this->fill_plt_entry(pov, got_address, plt_address,
7521                            got_offset, plt_offset);
7522
7523       // Set the entry in the GOT.
7524       elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7525     }
7526
7527   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7528   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7529
7530   of->write_output_view(offset, oview_size, oview);
7531   of->write_output_view(got_file_offset, got_size, got_view);
7532 }
7533
7534 // Create a PLT entry for a global symbol.
7535
7536 template<bool big_endian>
7537 void
7538 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7539                                        Symbol* gsym)
7540 {
7541   if (gsym->has_plt_offset())
7542     return;
7543
7544   if (this->plt_ == NULL)
7545     {
7546       // Create the GOT sections first.
7547       this->got_section(symtab, layout);
7548
7549       this->plt_ = this->make_data_plt(layout, this->got_plt_);
7550
7551       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7552                                       (elfcpp::SHF_ALLOC
7553                                        | elfcpp::SHF_EXECINSTR),
7554                                       this->plt_, ORDER_PLT, false);
7555     }
7556   this->plt_->add_entry(gsym);
7557 }
7558
7559 // Return the number of entries in the PLT.
7560
7561 template<bool big_endian>
7562 unsigned int
7563 Target_arm<big_endian>::plt_entry_count() const
7564 {
7565   if (this->plt_ == NULL)
7566     return 0;
7567   return this->plt_->entry_count();
7568 }
7569
7570 // Return the offset of the first non-reserved PLT entry.
7571
7572 template<bool big_endian>
7573 unsigned int
7574 Target_arm<big_endian>::first_plt_entry_offset() const
7575 {
7576   return this->plt_->first_plt_entry_offset();
7577 }
7578
7579 // Return the size of each PLT entry.
7580
7581 template<bool big_endian>
7582 unsigned int
7583 Target_arm<big_endian>::plt_entry_size() const
7584 {
7585   return this->plt_->get_plt_entry_size();
7586 }
7587
7588 // Get the section to use for TLS_DESC relocations.
7589
7590 template<bool big_endian>
7591 typename Target_arm<big_endian>::Reloc_section*
7592 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7593 {
7594   return this->plt_section()->rel_tls_desc(layout);
7595 }
7596
7597 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7598
7599 template<bool big_endian>
7600 void
7601 Target_arm<big_endian>::define_tls_base_symbol(
7602     Symbol_table* symtab,
7603     Layout* layout)
7604 {
7605   if (this->tls_base_symbol_defined_)
7606     return;
7607
7608   Output_segment* tls_segment = layout->tls_segment();
7609   if (tls_segment != NULL)
7610     {
7611       bool is_exec = parameters->options().output_is_executable();
7612       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7613                                        Symbol_table::PREDEFINED,
7614                                        tls_segment, 0, 0,
7615                                        elfcpp::STT_TLS,
7616                                        elfcpp::STB_LOCAL,
7617                                        elfcpp::STV_HIDDEN, 0,
7618                                        (is_exec
7619                                         ? Symbol::SEGMENT_END
7620                                         : Symbol::SEGMENT_START),
7621                                        true);
7622     }
7623   this->tls_base_symbol_defined_ = true;
7624 }
7625
7626 // Create a GOT entry for the TLS module index.
7627
7628 template<bool big_endian>
7629 unsigned int
7630 Target_arm<big_endian>::got_mod_index_entry(
7631     Symbol_table* symtab,
7632     Layout* layout,
7633     Sized_relobj_file<32, big_endian>* object)
7634 {
7635   if (this->got_mod_index_offset_ == -1U)
7636     {
7637       gold_assert(symtab != NULL && layout != NULL && object != NULL);
7638       Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7639       unsigned int got_offset;
7640       if (!parameters->doing_static_link())
7641         {
7642           got_offset = got->add_constant(0);
7643           Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7644           rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7645                              got_offset);
7646         }
7647       else
7648         {
7649           // We are doing a static link.  Just mark it as belong to module 1,
7650           // the executable.
7651           got_offset = got->add_constant(1);
7652         }
7653
7654       got->add_constant(0);
7655       this->got_mod_index_offset_ = got_offset;
7656     }
7657   return this->got_mod_index_offset_;
7658 }
7659
7660 // Optimize the TLS relocation type based on what we know about the
7661 // symbol.  IS_FINAL is true if the final address of this symbol is
7662 // known at link time.
7663
7664 template<bool big_endian>
7665 tls::Tls_optimization
7666 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7667 {
7668   // FIXME: Currently we do not do any TLS optimization.
7669   return tls::TLSOPT_NONE;
7670 }
7671
7672 // Get the Reference_flags for a particular relocation.
7673
7674 template<bool big_endian>
7675 int
7676 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
7677 {
7678   switch (r_type)
7679     {
7680     case elfcpp::R_ARM_NONE:
7681     case elfcpp::R_ARM_V4BX:
7682     case elfcpp::R_ARM_GNU_VTENTRY:
7683     case elfcpp::R_ARM_GNU_VTINHERIT:
7684       // No symbol reference.
7685       return 0;
7686
7687     case elfcpp::R_ARM_ABS32:
7688     case elfcpp::R_ARM_ABS16:
7689     case elfcpp::R_ARM_ABS12:
7690     case elfcpp::R_ARM_THM_ABS5:
7691     case elfcpp::R_ARM_ABS8:
7692     case elfcpp::R_ARM_BASE_ABS:
7693     case elfcpp::R_ARM_MOVW_ABS_NC:
7694     case elfcpp::R_ARM_MOVT_ABS:
7695     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7696     case elfcpp::R_ARM_THM_MOVT_ABS:
7697     case elfcpp::R_ARM_ABS32_NOI:
7698       return Symbol::ABSOLUTE_REF;
7699
7700     case elfcpp::R_ARM_REL32:
7701     case elfcpp::R_ARM_LDR_PC_G0:
7702     case elfcpp::R_ARM_SBREL32:
7703     case elfcpp::R_ARM_THM_PC8:
7704     case elfcpp::R_ARM_BASE_PREL:
7705     case elfcpp::R_ARM_MOVW_PREL_NC:
7706     case elfcpp::R_ARM_MOVT_PREL:
7707     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7708     case elfcpp::R_ARM_THM_MOVT_PREL:
7709     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7710     case elfcpp::R_ARM_THM_PC12:
7711     case elfcpp::R_ARM_REL32_NOI:
7712     case elfcpp::R_ARM_ALU_PC_G0_NC:
7713     case elfcpp::R_ARM_ALU_PC_G0:
7714     case elfcpp::R_ARM_ALU_PC_G1_NC:
7715     case elfcpp::R_ARM_ALU_PC_G1:
7716     case elfcpp::R_ARM_ALU_PC_G2:
7717     case elfcpp::R_ARM_LDR_PC_G1:
7718     case elfcpp::R_ARM_LDR_PC_G2:
7719     case elfcpp::R_ARM_LDRS_PC_G0:
7720     case elfcpp::R_ARM_LDRS_PC_G1:
7721     case elfcpp::R_ARM_LDRS_PC_G2:
7722     case elfcpp::R_ARM_LDC_PC_G0:
7723     case elfcpp::R_ARM_LDC_PC_G1:
7724     case elfcpp::R_ARM_LDC_PC_G2:
7725     case elfcpp::R_ARM_ALU_SB_G0_NC:
7726     case elfcpp::R_ARM_ALU_SB_G0:
7727     case elfcpp::R_ARM_ALU_SB_G1_NC:
7728     case elfcpp::R_ARM_ALU_SB_G1:
7729     case elfcpp::R_ARM_ALU_SB_G2:
7730     case elfcpp::R_ARM_LDR_SB_G0:
7731     case elfcpp::R_ARM_LDR_SB_G1:
7732     case elfcpp::R_ARM_LDR_SB_G2:
7733     case elfcpp::R_ARM_LDRS_SB_G0:
7734     case elfcpp::R_ARM_LDRS_SB_G1:
7735     case elfcpp::R_ARM_LDRS_SB_G2:
7736     case elfcpp::R_ARM_LDC_SB_G0:
7737     case elfcpp::R_ARM_LDC_SB_G1:
7738     case elfcpp::R_ARM_LDC_SB_G2:
7739     case elfcpp::R_ARM_MOVW_BREL_NC:
7740     case elfcpp::R_ARM_MOVT_BREL:
7741     case elfcpp::R_ARM_MOVW_BREL:
7742     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7743     case elfcpp::R_ARM_THM_MOVT_BREL:
7744     case elfcpp::R_ARM_THM_MOVW_BREL:
7745     case elfcpp::R_ARM_GOTOFF32:
7746     case elfcpp::R_ARM_GOTOFF12:
7747     case elfcpp::R_ARM_SBREL31:
7748       return Symbol::RELATIVE_REF;
7749
7750     case elfcpp::R_ARM_PLT32:
7751     case elfcpp::R_ARM_CALL:
7752     case elfcpp::R_ARM_JUMP24:
7753     case elfcpp::R_ARM_THM_CALL:
7754     case elfcpp::R_ARM_THM_JUMP24:
7755     case elfcpp::R_ARM_THM_JUMP19:
7756     case elfcpp::R_ARM_THM_JUMP6:
7757     case elfcpp::R_ARM_THM_JUMP11:
7758     case elfcpp::R_ARM_THM_JUMP8:
7759     // R_ARM_PREL31 is not used to relocate call/jump instructions but
7760     // in unwind tables. It may point to functions via PLTs.
7761     // So we treat it like call/jump relocations above.
7762     case elfcpp::R_ARM_PREL31:
7763       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
7764
7765     case elfcpp::R_ARM_GOT_BREL:
7766     case elfcpp::R_ARM_GOT_ABS:
7767     case elfcpp::R_ARM_GOT_PREL:
7768       // Absolute in GOT.
7769       return Symbol::ABSOLUTE_REF;
7770
7771     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
7772     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
7773     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
7774     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
7775     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
7776       return Symbol::TLS_REF;
7777
7778     case elfcpp::R_ARM_TARGET1:
7779     case elfcpp::R_ARM_TARGET2:
7780     case elfcpp::R_ARM_COPY:
7781     case elfcpp::R_ARM_GLOB_DAT:
7782     case elfcpp::R_ARM_JUMP_SLOT:
7783     case elfcpp::R_ARM_RELATIVE:
7784     case elfcpp::R_ARM_PC24:
7785     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7786     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7787     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7788     default:
7789       // Not expected.  We will give an error later.
7790       return 0;
7791     }
7792 }
7793
7794 // Report an unsupported relocation against a local symbol.
7795
7796 template<bool big_endian>
7797 void
7798 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7799     Sized_relobj_file<32, big_endian>* object,
7800     unsigned int r_type)
7801 {
7802   gold_error(_("%s: unsupported reloc %u against local symbol"),
7803              object->name().c_str(), r_type);
7804 }
7805
7806 // We are about to emit a dynamic relocation of type R_TYPE.  If the
7807 // dynamic linker does not support it, issue an error.  The GNU linker
7808 // only issues a non-PIC error for an allocated read-only section.
7809 // Here we know the section is allocated, but we don't know that it is
7810 // read-only.  But we check for all the relocation types which the
7811 // glibc dynamic linker supports, so it seems appropriate to issue an
7812 // error even if the section is not read-only.
7813
7814 template<bool big_endian>
7815 void
7816 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7817                                             unsigned int r_type)
7818 {
7819   switch (r_type)
7820     {
7821     // These are the relocation types supported by glibc for ARM.
7822     case elfcpp::R_ARM_RELATIVE:
7823     case elfcpp::R_ARM_COPY:
7824     case elfcpp::R_ARM_GLOB_DAT:
7825     case elfcpp::R_ARM_JUMP_SLOT:
7826     case elfcpp::R_ARM_ABS32:
7827     case elfcpp::R_ARM_ABS32_NOI:
7828     case elfcpp::R_ARM_PC24:
7829     // FIXME: The following 3 types are not supported by Android's dynamic
7830     // linker.
7831     case elfcpp::R_ARM_TLS_DTPMOD32:
7832     case elfcpp::R_ARM_TLS_DTPOFF32:
7833     case elfcpp::R_ARM_TLS_TPOFF32:
7834       return;
7835
7836     default:
7837       {
7838         // This prevents us from issuing more than one error per reloc
7839         // section.  But we can still wind up issuing more than one
7840         // error per object file.
7841         if (this->issued_non_pic_error_)
7842           return;
7843         const Arm_reloc_property* reloc_property =
7844           arm_reloc_property_table->get_reloc_property(r_type);
7845         gold_assert(reloc_property != NULL);
7846         object->error(_("requires unsupported dynamic reloc %s; "
7847                       "recompile with -fPIC"),
7848                       reloc_property->name().c_str());
7849         this->issued_non_pic_error_ = true;
7850         return;
7851       }
7852
7853     case elfcpp::R_ARM_NONE:
7854       gold_unreachable();
7855     }
7856 }
7857
7858 // Scan a relocation for a local symbol.
7859 // FIXME: This only handles a subset of relocation types used by Android
7860 // on ARM v5te devices.
7861
7862 template<bool big_endian>
7863 inline void
7864 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7865                                     Layout* layout,
7866                                     Target_arm* target,
7867                                     Sized_relobj_file<32, big_endian>* object,
7868                                     unsigned int data_shndx,
7869                                     Output_section* output_section,
7870                                     const elfcpp::Rel<32, big_endian>& reloc,
7871                                     unsigned int r_type,
7872                                     const elfcpp::Sym<32, big_endian>& lsym,
7873                                     bool is_discarded)
7874 {
7875   if (is_discarded)
7876     return;
7877
7878   r_type = get_real_reloc_type(r_type);
7879   switch (r_type)
7880     {
7881     case elfcpp::R_ARM_NONE:
7882     case elfcpp::R_ARM_V4BX:
7883     case elfcpp::R_ARM_GNU_VTENTRY:
7884     case elfcpp::R_ARM_GNU_VTINHERIT:
7885       break;
7886
7887     case elfcpp::R_ARM_ABS32:
7888     case elfcpp::R_ARM_ABS32_NOI:
7889       // If building a shared library (or a position-independent
7890       // executable), we need to create a dynamic relocation for
7891       // this location. The relocation applied at link time will
7892       // apply the link-time value, so we flag the location with
7893       // an R_ARM_RELATIVE relocation so the dynamic loader can
7894       // relocate it easily.
7895       if (parameters->options().output_is_position_independent())
7896         {
7897           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7898           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7899           // If we are to add more other reloc types than R_ARM_ABS32,
7900           // we need to add check_non_pic(object, r_type) here.
7901           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7902                                       output_section, data_shndx,
7903                                       reloc.get_r_offset());
7904         }
7905       break;
7906
7907     case elfcpp::R_ARM_ABS16:
7908     case elfcpp::R_ARM_ABS12:
7909     case elfcpp::R_ARM_THM_ABS5:
7910     case elfcpp::R_ARM_ABS8:
7911     case elfcpp::R_ARM_BASE_ABS:
7912     case elfcpp::R_ARM_MOVW_ABS_NC:
7913     case elfcpp::R_ARM_MOVT_ABS:
7914     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7915     case elfcpp::R_ARM_THM_MOVT_ABS:
7916       // If building a shared library (or a position-independent
7917       // executable), we need to create a dynamic relocation for
7918       // this location. Because the addend needs to remain in the
7919       // data section, we need to be careful not to apply this
7920       // relocation statically.
7921       if (parameters->options().output_is_position_independent())
7922         {
7923           check_non_pic(object, r_type);
7924           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7925           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7926           if (lsym.get_st_type() != elfcpp::STT_SECTION)
7927             rel_dyn->add_local(object, r_sym, r_type, output_section,
7928                                data_shndx, reloc.get_r_offset());
7929           else
7930             {
7931               gold_assert(lsym.get_st_value() == 0);
7932               unsigned int shndx = lsym.get_st_shndx();
7933               bool is_ordinary;
7934               shndx = object->adjust_sym_shndx(r_sym, shndx,
7935                                                &is_ordinary);
7936               if (!is_ordinary)
7937                 object->error(_("section symbol %u has bad shndx %u"),
7938                               r_sym, shndx);
7939               else
7940                 rel_dyn->add_local_section(object, shndx,
7941                                            r_type, output_section,
7942                                            data_shndx, reloc.get_r_offset());
7943             }
7944         }
7945       break;
7946
7947     case elfcpp::R_ARM_REL32:
7948     case elfcpp::R_ARM_LDR_PC_G0:
7949     case elfcpp::R_ARM_SBREL32:
7950     case elfcpp::R_ARM_THM_CALL:
7951     case elfcpp::R_ARM_THM_PC8:
7952     case elfcpp::R_ARM_BASE_PREL:
7953     case elfcpp::R_ARM_PLT32:
7954     case elfcpp::R_ARM_CALL:
7955     case elfcpp::R_ARM_JUMP24:
7956     case elfcpp::R_ARM_THM_JUMP24:
7957     case elfcpp::R_ARM_SBREL31:
7958     case elfcpp::R_ARM_PREL31:
7959     case elfcpp::R_ARM_MOVW_PREL_NC:
7960     case elfcpp::R_ARM_MOVT_PREL:
7961     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7962     case elfcpp::R_ARM_THM_MOVT_PREL:
7963     case elfcpp::R_ARM_THM_JUMP19:
7964     case elfcpp::R_ARM_THM_JUMP6:
7965     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7966     case elfcpp::R_ARM_THM_PC12:
7967     case elfcpp::R_ARM_REL32_NOI:
7968     case elfcpp::R_ARM_ALU_PC_G0_NC:
7969     case elfcpp::R_ARM_ALU_PC_G0:
7970     case elfcpp::R_ARM_ALU_PC_G1_NC:
7971     case elfcpp::R_ARM_ALU_PC_G1:
7972     case elfcpp::R_ARM_ALU_PC_G2:
7973     case elfcpp::R_ARM_LDR_PC_G1:
7974     case elfcpp::R_ARM_LDR_PC_G2:
7975     case elfcpp::R_ARM_LDRS_PC_G0:
7976     case elfcpp::R_ARM_LDRS_PC_G1:
7977     case elfcpp::R_ARM_LDRS_PC_G2:
7978     case elfcpp::R_ARM_LDC_PC_G0:
7979     case elfcpp::R_ARM_LDC_PC_G1:
7980     case elfcpp::R_ARM_LDC_PC_G2:
7981     case elfcpp::R_ARM_ALU_SB_G0_NC:
7982     case elfcpp::R_ARM_ALU_SB_G0:
7983     case elfcpp::R_ARM_ALU_SB_G1_NC:
7984     case elfcpp::R_ARM_ALU_SB_G1:
7985     case elfcpp::R_ARM_ALU_SB_G2:
7986     case elfcpp::R_ARM_LDR_SB_G0:
7987     case elfcpp::R_ARM_LDR_SB_G1:
7988     case elfcpp::R_ARM_LDR_SB_G2:
7989     case elfcpp::R_ARM_LDRS_SB_G0:
7990     case elfcpp::R_ARM_LDRS_SB_G1:
7991     case elfcpp::R_ARM_LDRS_SB_G2:
7992     case elfcpp::R_ARM_LDC_SB_G0:
7993     case elfcpp::R_ARM_LDC_SB_G1:
7994     case elfcpp::R_ARM_LDC_SB_G2:
7995     case elfcpp::R_ARM_MOVW_BREL_NC:
7996     case elfcpp::R_ARM_MOVT_BREL:
7997     case elfcpp::R_ARM_MOVW_BREL:
7998     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7999     case elfcpp::R_ARM_THM_MOVT_BREL:
8000     case elfcpp::R_ARM_THM_MOVW_BREL:
8001     case elfcpp::R_ARM_THM_JUMP11:
8002     case elfcpp::R_ARM_THM_JUMP8:
8003       // We don't need to do anything for a relative addressing relocation
8004       // against a local symbol if it does not reference the GOT.
8005       break;
8006
8007     case elfcpp::R_ARM_GOTOFF32:
8008     case elfcpp::R_ARM_GOTOFF12:
8009       // We need a GOT section:
8010       target->got_section(symtab, layout);
8011       break;
8012
8013     case elfcpp::R_ARM_GOT_BREL:
8014     case elfcpp::R_ARM_GOT_PREL:
8015       {
8016         // The symbol requires a GOT entry.
8017         Arm_output_data_got<big_endian>* got =
8018           target->got_section(symtab, layout);
8019         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8020         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
8021           {
8022             // If we are generating a shared object, we need to add a
8023             // dynamic RELATIVE relocation for this symbol's GOT entry.
8024             if (parameters->options().output_is_position_independent())
8025               {
8026                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8027                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8028                 rel_dyn->add_local_relative(
8029                     object, r_sym, elfcpp::R_ARM_RELATIVE, got,
8030                     object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
8031               }
8032           }
8033       }
8034       break;
8035
8036     case elfcpp::R_ARM_TARGET1:
8037     case elfcpp::R_ARM_TARGET2:
8038       // This should have been mapped to another type already.
8039       // Fall through.
8040     case elfcpp::R_ARM_COPY:
8041     case elfcpp::R_ARM_GLOB_DAT:
8042     case elfcpp::R_ARM_JUMP_SLOT:
8043     case elfcpp::R_ARM_RELATIVE:
8044       // These are relocations which should only be seen by the
8045       // dynamic linker, and should never be seen here.
8046       gold_error(_("%s: unexpected reloc %u in object file"),
8047                  object->name().c_str(), r_type);
8048       break;
8049
8050
8051       // These are initial TLS relocs, which are expected when
8052       // linking.
8053     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8054     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8055     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8056     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8057     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8058       {
8059         bool output_is_shared = parameters->options().shared();
8060         const tls::Tls_optimization optimized_type
8061             = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
8062                                                          r_type);
8063         switch (r_type)
8064           {
8065           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8066             if (optimized_type == tls::TLSOPT_NONE)
8067               {
8068                 // Create a pair of GOT entries for the module index and
8069                 // dtv-relative offset.
8070                 Arm_output_data_got<big_endian>* got
8071                     = target->got_section(symtab, layout);
8072                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8073                 unsigned int shndx = lsym.get_st_shndx();
8074                 bool is_ordinary;
8075                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
8076                 if (!is_ordinary)
8077                   {
8078                     object->error(_("local symbol %u has bad shndx %u"),
8079                                   r_sym, shndx);
8080                     break;
8081                   }
8082
8083                 if (!parameters->doing_static_link())
8084                   got->add_local_pair_with_rel(object, r_sym, shndx,
8085                                                GOT_TYPE_TLS_PAIR,
8086                                                target->rel_dyn_section(layout),
8087                                                elfcpp::R_ARM_TLS_DTPMOD32);
8088                 else
8089                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
8090                                                       object, r_sym);
8091               }
8092             else
8093               // FIXME: TLS optimization not supported yet.
8094               gold_unreachable();
8095             break;
8096
8097           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
8098             if (optimized_type == tls::TLSOPT_NONE)
8099               {
8100                 // Create a GOT entry for the module index.
8101                 target->got_mod_index_entry(symtab, layout, object);
8102               }
8103             else
8104               // FIXME: TLS optimization not supported yet.
8105               gold_unreachable();
8106             break;
8107
8108           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
8109             break;
8110
8111           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
8112             layout->set_has_static_tls();
8113             if (optimized_type == tls::TLSOPT_NONE)
8114               {
8115                 // Create a GOT entry for the tp-relative offset.
8116                 Arm_output_data_got<big_endian>* got
8117                   = target->got_section(symtab, layout);
8118                 unsigned int r_sym =
8119                    elfcpp::elf_r_sym<32>(reloc.get_r_info());
8120                 if (!parameters->doing_static_link())
8121                     got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
8122                                             target->rel_dyn_section(layout),
8123                                             elfcpp::R_ARM_TLS_TPOFF32);
8124                 else if (!object->local_has_got_offset(r_sym,
8125                                                        GOT_TYPE_TLS_OFFSET))
8126                   {
8127                     got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
8128                     unsigned int got_offset =
8129                       object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
8130                     got->add_static_reloc(got_offset,
8131                                           elfcpp::R_ARM_TLS_TPOFF32, object,
8132                                           r_sym);
8133                   }
8134               }
8135             else
8136               // FIXME: TLS optimization not supported yet.
8137               gold_unreachable();
8138             break;
8139
8140           case elfcpp::R_ARM_TLS_LE32:          // Local-exec
8141             layout->set_has_static_tls();
8142             if (output_is_shared)
8143               {
8144                 // We need to create a dynamic relocation.
8145                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8146                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8147                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8148                 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8149                                    output_section, data_shndx,
8150                                    reloc.get_r_offset());
8151               }
8152             break;
8153
8154           default:
8155             gold_unreachable();
8156           }
8157       }
8158       break;
8159
8160     case elfcpp::R_ARM_PC24:
8161     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8162     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8163     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8164     default:
8165       unsupported_reloc_local(object, r_type);
8166       break;
8167     }
8168 }
8169
8170 // Report an unsupported relocation against a global symbol.
8171
8172 template<bool big_endian>
8173 void
8174 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8175     Sized_relobj_file<32, big_endian>* object,
8176     unsigned int r_type,
8177     Symbol* gsym)
8178 {
8179   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8180              object->name().c_str(), r_type, gsym->demangled_name().c_str());
8181 }
8182
8183 template<bool big_endian>
8184 inline bool
8185 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8186     unsigned int r_type)
8187 {
8188   switch (r_type)
8189     {
8190     case elfcpp::R_ARM_PC24:
8191     case elfcpp::R_ARM_THM_CALL:
8192     case elfcpp::R_ARM_PLT32:
8193     case elfcpp::R_ARM_CALL:
8194     case elfcpp::R_ARM_JUMP24:
8195     case elfcpp::R_ARM_THM_JUMP24:
8196     case elfcpp::R_ARM_SBREL31:
8197     case elfcpp::R_ARM_PREL31:
8198     case elfcpp::R_ARM_THM_JUMP19:
8199     case elfcpp::R_ARM_THM_JUMP6:
8200     case elfcpp::R_ARM_THM_JUMP11:
8201     case elfcpp::R_ARM_THM_JUMP8:
8202       // All the relocations above are branches except SBREL31 and PREL31.
8203       return false;
8204
8205     default:
8206       // Be conservative and assume this is a function pointer.
8207       return true;
8208     }
8209 }
8210
8211 template<bool big_endian>
8212 inline bool
8213 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8214   Symbol_table*,
8215   Layout*,
8216   Target_arm<big_endian>* target,
8217   Sized_relobj_file<32, big_endian>*,
8218   unsigned int,
8219   Output_section*,
8220   const elfcpp::Rel<32, big_endian>&,
8221   unsigned int r_type,
8222   const elfcpp::Sym<32, big_endian>&)
8223 {
8224   r_type = target->get_real_reloc_type(r_type);
8225   return possible_function_pointer_reloc(r_type);
8226 }
8227
8228 template<bool big_endian>
8229 inline bool
8230 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8231   Symbol_table*,
8232   Layout*,
8233   Target_arm<big_endian>* target,
8234   Sized_relobj_file<32, big_endian>*,
8235   unsigned int,
8236   Output_section*,
8237   const elfcpp::Rel<32, big_endian>&,
8238   unsigned int r_type,
8239   Symbol* gsym)
8240 {
8241   // GOT is not a function.
8242   if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8243     return false;
8244
8245   r_type = target->get_real_reloc_type(r_type);
8246   return possible_function_pointer_reloc(r_type);
8247 }
8248
8249 // Scan a relocation for a global symbol.
8250
8251 template<bool big_endian>
8252 inline void
8253 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8254                                      Layout* layout,
8255                                      Target_arm* target,
8256                                      Sized_relobj_file<32, big_endian>* object,
8257                                      unsigned int data_shndx,
8258                                      Output_section* output_section,
8259                                      const elfcpp::Rel<32, big_endian>& reloc,
8260                                      unsigned int r_type,
8261                                      Symbol* gsym)
8262 {
8263   // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8264   // section.  We check here to avoid creating a dynamic reloc against
8265   // _GLOBAL_OFFSET_TABLE_.
8266   if (!target->has_got_section()
8267       && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8268     target->got_section(symtab, layout);
8269
8270   r_type = get_real_reloc_type(r_type);
8271   switch (r_type)
8272     {
8273     case elfcpp::R_ARM_NONE:
8274     case elfcpp::R_ARM_V4BX:
8275     case elfcpp::R_ARM_GNU_VTENTRY:
8276     case elfcpp::R_ARM_GNU_VTINHERIT:
8277       break;
8278
8279     case elfcpp::R_ARM_ABS32:
8280     case elfcpp::R_ARM_ABS16:
8281     case elfcpp::R_ARM_ABS12:
8282     case elfcpp::R_ARM_THM_ABS5:
8283     case elfcpp::R_ARM_ABS8:
8284     case elfcpp::R_ARM_BASE_ABS:
8285     case elfcpp::R_ARM_MOVW_ABS_NC:
8286     case elfcpp::R_ARM_MOVT_ABS:
8287     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8288     case elfcpp::R_ARM_THM_MOVT_ABS:
8289     case elfcpp::R_ARM_ABS32_NOI:
8290       // Absolute addressing relocations.
8291       {
8292         // Make a PLT entry if necessary.
8293         if (this->symbol_needs_plt_entry(gsym))
8294           {
8295             target->make_plt_entry(symtab, layout, gsym);
8296             // Since this is not a PC-relative relocation, we may be
8297             // taking the address of a function. In that case we need to
8298             // set the entry in the dynamic symbol table to the address of
8299             // the PLT entry.
8300             if (gsym->is_from_dynobj() && !parameters->options().shared())
8301               gsym->set_needs_dynsym_value();
8302           }
8303         // Make a dynamic relocation if necessary.
8304         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8305           {
8306             if (gsym->may_need_copy_reloc())
8307               {
8308                 target->copy_reloc(symtab, layout, object,
8309                                    data_shndx, output_section, gsym, reloc);
8310               }
8311             else if ((r_type == elfcpp::R_ARM_ABS32
8312                       || r_type == elfcpp::R_ARM_ABS32_NOI)
8313                      && gsym->can_use_relative_reloc(false))
8314               {
8315                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8316                 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8317                                              output_section, object,
8318                                              data_shndx, reloc.get_r_offset());
8319               }
8320             else
8321               {
8322                 check_non_pic(object, r_type);
8323                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8324                 rel_dyn->add_global(gsym, r_type, output_section, object,
8325                                     data_shndx, reloc.get_r_offset());
8326               }
8327           }
8328       }
8329       break;
8330
8331     case elfcpp::R_ARM_GOTOFF32:
8332     case elfcpp::R_ARM_GOTOFF12:
8333       // We need a GOT section.
8334       target->got_section(symtab, layout);
8335       break;
8336
8337     case elfcpp::R_ARM_REL32:
8338     case elfcpp::R_ARM_LDR_PC_G0:
8339     case elfcpp::R_ARM_SBREL32:
8340     case elfcpp::R_ARM_THM_PC8:
8341     case elfcpp::R_ARM_BASE_PREL:
8342     case elfcpp::R_ARM_MOVW_PREL_NC:
8343     case elfcpp::R_ARM_MOVT_PREL:
8344     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8345     case elfcpp::R_ARM_THM_MOVT_PREL:
8346     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8347     case elfcpp::R_ARM_THM_PC12:
8348     case elfcpp::R_ARM_REL32_NOI:
8349     case elfcpp::R_ARM_ALU_PC_G0_NC:
8350     case elfcpp::R_ARM_ALU_PC_G0:
8351     case elfcpp::R_ARM_ALU_PC_G1_NC:
8352     case elfcpp::R_ARM_ALU_PC_G1:
8353     case elfcpp::R_ARM_ALU_PC_G2:
8354     case elfcpp::R_ARM_LDR_PC_G1:
8355     case elfcpp::R_ARM_LDR_PC_G2:
8356     case elfcpp::R_ARM_LDRS_PC_G0:
8357     case elfcpp::R_ARM_LDRS_PC_G1:
8358     case elfcpp::R_ARM_LDRS_PC_G2:
8359     case elfcpp::R_ARM_LDC_PC_G0:
8360     case elfcpp::R_ARM_LDC_PC_G1:
8361     case elfcpp::R_ARM_LDC_PC_G2:
8362     case elfcpp::R_ARM_ALU_SB_G0_NC:
8363     case elfcpp::R_ARM_ALU_SB_G0:
8364     case elfcpp::R_ARM_ALU_SB_G1_NC:
8365     case elfcpp::R_ARM_ALU_SB_G1:
8366     case elfcpp::R_ARM_ALU_SB_G2:
8367     case elfcpp::R_ARM_LDR_SB_G0:
8368     case elfcpp::R_ARM_LDR_SB_G1:
8369     case elfcpp::R_ARM_LDR_SB_G2:
8370     case elfcpp::R_ARM_LDRS_SB_G0:
8371     case elfcpp::R_ARM_LDRS_SB_G1:
8372     case elfcpp::R_ARM_LDRS_SB_G2:
8373     case elfcpp::R_ARM_LDC_SB_G0:
8374     case elfcpp::R_ARM_LDC_SB_G1:
8375     case elfcpp::R_ARM_LDC_SB_G2:
8376     case elfcpp::R_ARM_MOVW_BREL_NC:
8377     case elfcpp::R_ARM_MOVT_BREL:
8378     case elfcpp::R_ARM_MOVW_BREL:
8379     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8380     case elfcpp::R_ARM_THM_MOVT_BREL:
8381     case elfcpp::R_ARM_THM_MOVW_BREL:
8382       // Relative addressing relocations.
8383       {
8384         // Make a dynamic relocation if necessary.
8385         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8386           {
8387             if (target->may_need_copy_reloc(gsym))
8388               {
8389                 target->copy_reloc(symtab, layout, object,
8390                                    data_shndx, output_section, gsym, reloc);
8391               }
8392             else
8393               {
8394                 check_non_pic(object, r_type);
8395                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8396                 rel_dyn->add_global(gsym, r_type, output_section, object,
8397                                     data_shndx, reloc.get_r_offset());
8398               }
8399           }
8400       }
8401       break;
8402
8403     case elfcpp::R_ARM_THM_CALL:
8404     case elfcpp::R_ARM_PLT32:
8405     case elfcpp::R_ARM_CALL:
8406     case elfcpp::R_ARM_JUMP24:
8407     case elfcpp::R_ARM_THM_JUMP24:
8408     case elfcpp::R_ARM_SBREL31:
8409     case elfcpp::R_ARM_PREL31:
8410     case elfcpp::R_ARM_THM_JUMP19:
8411     case elfcpp::R_ARM_THM_JUMP6:
8412     case elfcpp::R_ARM_THM_JUMP11:
8413     case elfcpp::R_ARM_THM_JUMP8:
8414       // All the relocation above are branches except for the PREL31 ones.
8415       // A PREL31 relocation can point to a personality function in a shared
8416       // library.  In that case we want to use a PLT because we want to
8417       // call the personality routine and the dynamic linkers we care about
8418       // do not support dynamic PREL31 relocations. An REL31 relocation may
8419       // point to a function whose unwinding behaviour is being described but
8420       // we will not mistakenly generate a PLT for that because we should use
8421       // a local section symbol.
8422
8423       // If the symbol is fully resolved, this is just a relative
8424       // local reloc.  Otherwise we need a PLT entry.
8425       if (gsym->final_value_is_known())
8426         break;
8427       // If building a shared library, we can also skip the PLT entry
8428       // if the symbol is defined in the output file and is protected
8429       // or hidden.
8430       if (gsym->is_defined()
8431           && !gsym->is_from_dynobj()
8432           && !gsym->is_preemptible())
8433         break;
8434       target->make_plt_entry(symtab, layout, gsym);
8435       break;
8436
8437     case elfcpp::R_ARM_GOT_BREL:
8438     case elfcpp::R_ARM_GOT_ABS:
8439     case elfcpp::R_ARM_GOT_PREL:
8440       {
8441         // The symbol requires a GOT entry.
8442         Arm_output_data_got<big_endian>* got =
8443           target->got_section(symtab, layout);
8444         if (gsym->final_value_is_known())
8445           got->add_global(gsym, GOT_TYPE_STANDARD);
8446         else
8447           {
8448             // If this symbol is not fully resolved, we need to add a
8449             // GOT entry with a dynamic relocation.
8450             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8451             if (gsym->is_from_dynobj()
8452                 || gsym->is_undefined()
8453                 || gsym->is_preemptible()
8454                 || (gsym->visibility() == elfcpp::STV_PROTECTED
8455                     && parameters->options().shared()))
8456               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8457                                        rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8458             else
8459               {
8460                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
8461                   rel_dyn->add_global_relative(
8462                       gsym, elfcpp::R_ARM_RELATIVE, got,
8463                       gsym->got_offset(GOT_TYPE_STANDARD));
8464               }
8465           }
8466       }
8467       break;
8468
8469     case elfcpp::R_ARM_TARGET1:
8470     case elfcpp::R_ARM_TARGET2:
8471       // These should have been mapped to other types already.
8472       // Fall through.
8473     case elfcpp::R_ARM_COPY:
8474     case elfcpp::R_ARM_GLOB_DAT:
8475     case elfcpp::R_ARM_JUMP_SLOT:
8476     case elfcpp::R_ARM_RELATIVE:
8477       // These are relocations which should only be seen by the
8478       // dynamic linker, and should never be seen here.
8479       gold_error(_("%s: unexpected reloc %u in object file"),
8480                  object->name().c_str(), r_type);
8481       break;
8482
8483       // These are initial tls relocs, which are expected when
8484       // linking.
8485     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8486     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8487     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8488     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8489     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8490       {
8491         const bool is_final = gsym->final_value_is_known();
8492         const tls::Tls_optimization optimized_type
8493             = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8494         switch (r_type)
8495           {
8496           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8497             if (optimized_type == tls::TLSOPT_NONE)
8498               {
8499                 // Create a pair of GOT entries for the module index and
8500                 // dtv-relative offset.
8501                 Arm_output_data_got<big_endian>* got
8502                     = target->got_section(symtab, layout);
8503                 if (!parameters->doing_static_link())
8504                   got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8505                                                 target->rel_dyn_section(layout),
8506                                                 elfcpp::R_ARM_TLS_DTPMOD32,
8507                                                 elfcpp::R_ARM_TLS_DTPOFF32);
8508                 else
8509                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8510               }
8511             else
8512               // FIXME: TLS optimization not supported yet.
8513               gold_unreachable();
8514             break;
8515
8516           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
8517             if (optimized_type == tls::TLSOPT_NONE)
8518               {
8519                 // Create a GOT entry for the module index.
8520                 target->got_mod_index_entry(symtab, layout, object);
8521               }
8522             else
8523               // FIXME: TLS optimization not supported yet.
8524               gold_unreachable();
8525             break;
8526
8527           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
8528             break;
8529
8530           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
8531             layout->set_has_static_tls();
8532             if (optimized_type == tls::TLSOPT_NONE)
8533               {
8534                 // Create a GOT entry for the tp-relative offset.
8535                 Arm_output_data_got<big_endian>* got
8536                   = target->got_section(symtab, layout);
8537                 if (!parameters->doing_static_link())
8538                   got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
8539                                            target->rel_dyn_section(layout),
8540                                            elfcpp::R_ARM_TLS_TPOFF32);
8541                 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
8542                   {
8543                     got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
8544                     unsigned int got_offset =
8545                        gsym->got_offset(GOT_TYPE_TLS_OFFSET);
8546                     got->add_static_reloc(got_offset,
8547                                           elfcpp::R_ARM_TLS_TPOFF32, gsym);
8548                   }
8549               }
8550             else
8551               // FIXME: TLS optimization not supported yet.
8552               gold_unreachable();
8553             break;
8554
8555           case elfcpp::R_ARM_TLS_LE32:  // Local-exec
8556             layout->set_has_static_tls();
8557             if (parameters->options().shared())
8558               {
8559                 // We need to create a dynamic relocation.
8560                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8561                 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
8562                                     output_section, object,
8563                                     data_shndx, reloc.get_r_offset());
8564               }
8565             break;
8566
8567           default:
8568             gold_unreachable();
8569           }
8570       }
8571       break;
8572
8573     case elfcpp::R_ARM_PC24:
8574     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8575     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8576     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8577     default:
8578       unsupported_reloc_global(object, r_type, gsym);
8579       break;
8580     }
8581 }
8582
8583 // Process relocations for gc.
8584
8585 template<bool big_endian>
8586 void
8587 Target_arm<big_endian>::gc_process_relocs(
8588     Symbol_table* symtab,
8589     Layout* layout,
8590     Sized_relobj_file<32, big_endian>* object,
8591     unsigned int data_shndx,
8592     unsigned int,
8593     const unsigned char* prelocs,
8594     size_t reloc_count,
8595     Output_section* output_section,
8596     bool needs_special_offset_handling,
8597     size_t local_symbol_count,
8598     const unsigned char* plocal_symbols)
8599 {
8600   typedef Target_arm<big_endian> Arm;
8601   typedef typename Target_arm<big_endian>::Scan Scan;
8602
8603   gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
8604                           typename Target_arm::Relocatable_size_for_reloc>(
8605     symtab,
8606     layout,
8607     this,
8608     object,
8609     data_shndx,
8610     prelocs,
8611     reloc_count,
8612     output_section,
8613     needs_special_offset_handling,
8614     local_symbol_count,
8615     plocal_symbols);
8616 }
8617
8618 // Scan relocations for a section.
8619
8620 template<bool big_endian>
8621 void
8622 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
8623                                     Layout* layout,
8624                                     Sized_relobj_file<32, big_endian>* object,
8625                                     unsigned int data_shndx,
8626                                     unsigned int sh_type,
8627                                     const unsigned char* prelocs,
8628                                     size_t reloc_count,
8629                                     Output_section* output_section,
8630                                     bool needs_special_offset_handling,
8631                                     size_t local_symbol_count,
8632                                     const unsigned char* plocal_symbols)
8633 {
8634   typedef typename Target_arm<big_endian>::Scan Scan;
8635   if (sh_type == elfcpp::SHT_RELA)
8636     {
8637       gold_error(_("%s: unsupported RELA reloc section"),
8638                  object->name().c_str());
8639       return;
8640     }
8641
8642   gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
8643     symtab,
8644     layout,
8645     this,
8646     object,
8647     data_shndx,
8648     prelocs,
8649     reloc_count,
8650     output_section,
8651     needs_special_offset_handling,
8652     local_symbol_count,
8653     plocal_symbols);
8654 }
8655
8656 // Finalize the sections.
8657
8658 template<bool big_endian>
8659 void
8660 Target_arm<big_endian>::do_finalize_sections(
8661     Layout* layout,
8662     const Input_objects* input_objects,
8663     Symbol_table*)
8664 {
8665   bool merged_any_attributes = false;
8666   // Merge processor-specific flags.
8667   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
8668        p != input_objects->relobj_end();
8669        ++p)
8670     {
8671       Arm_relobj<big_endian>* arm_relobj =
8672         Arm_relobj<big_endian>::as_arm_relobj(*p);
8673       if (arm_relobj->merge_flags_and_attributes())
8674         {
8675           this->merge_processor_specific_flags(
8676               arm_relobj->name(),
8677               arm_relobj->processor_specific_flags());
8678           this->merge_object_attributes(arm_relobj->name().c_str(),
8679                                         arm_relobj->attributes_section_data());
8680           merged_any_attributes = true;
8681         }
8682     }
8683
8684   for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
8685        p != input_objects->dynobj_end();
8686        ++p)
8687     {
8688       Arm_dynobj<big_endian>* arm_dynobj =
8689         Arm_dynobj<big_endian>::as_arm_dynobj(*p);
8690       this->merge_processor_specific_flags(
8691           arm_dynobj->name(),
8692           arm_dynobj->processor_specific_flags());
8693       this->merge_object_attributes(arm_dynobj->name().c_str(),
8694                                     arm_dynobj->attributes_section_data());
8695       merged_any_attributes = true;
8696     }
8697
8698   // Create an empty uninitialized attribute section if we still don't have it
8699   // at this moment.  This happens if there is no attributes sections in all
8700   // inputs.
8701   if (this->attributes_section_data_ == NULL)
8702     this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
8703
8704   const Object_attribute* cpu_arch_attr =
8705     this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
8706   // Check if we need to use Cortex-A8 workaround.
8707   if (parameters->options().user_set_fix_cortex_a8())
8708     this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
8709   else
8710     {
8711       // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
8712       // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
8713       // profile.
8714       const Object_attribute* cpu_arch_profile_attr =
8715         this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
8716       this->fix_cortex_a8_ =
8717         (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
8718          && (cpu_arch_profile_attr->int_value() == 'A'
8719              || cpu_arch_profile_attr->int_value() == 0));
8720     }
8721
8722   // Check if we can use V4BX interworking.
8723   // The V4BX interworking stub contains BX instruction,
8724   // which is not specified for some profiles.
8725   if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
8726       && !this->may_use_v4t_interworking())
8727     gold_error(_("unable to provide V4BX reloc interworking fix up; "
8728                  "the target profile does not support BX instruction"));
8729
8730   // Fill in some more dynamic tags.
8731   const Reloc_section* rel_plt = (this->plt_ == NULL
8732                                   ? NULL
8733                                   : this->plt_->rel_plt());
8734   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
8735                                   this->rel_dyn_, true, false);
8736
8737   // Emit any relocs we saved in an attempt to avoid generating COPY
8738   // relocs.
8739   if (this->copy_relocs_.any_saved_relocs())
8740     this->copy_relocs_.emit(this->rel_dyn_section(layout));
8741
8742   // Handle the .ARM.exidx section.
8743   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8744
8745   if (!parameters->options().relocatable())
8746     {
8747       if (exidx_section != NULL
8748           && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
8749         {
8750           // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8751           // the .ARM.exidx section.
8752           if (!layout->script_options()->saw_phdrs_clause())
8753             {
8754               gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
8755                                                       0)
8756                           == NULL);
8757               Output_segment*  exidx_segment =
8758                 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8759               exidx_segment->add_output_section_to_nonload(exidx_section,
8760                                                            elfcpp::PF_R);
8761             }
8762         }
8763     }
8764
8765   // Create an .ARM.attributes section if we have merged any attributes
8766   // from inputs.
8767   if (merged_any_attributes)
8768     {
8769       Output_attributes_section_data* attributes_section =
8770       new Output_attributes_section_data(*this->attributes_section_data_);
8771       layout->add_output_section_data(".ARM.attributes",
8772                                       elfcpp::SHT_ARM_ATTRIBUTES, 0,
8773                                       attributes_section, ORDER_INVALID,
8774                                       false);
8775     }
8776
8777   // Fix up links in section EXIDX headers.
8778   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
8779        p != layout->section_list().end();
8780        ++p)
8781     if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
8782       {
8783         Arm_output_section<big_endian>* os =
8784           Arm_output_section<big_endian>::as_arm_output_section(*p);
8785         os->set_exidx_section_link();
8786       }
8787 }
8788
8789 // Return whether a direct absolute static relocation needs to be applied.
8790 // In cases where Scan::local() or Scan::global() has created
8791 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8792 // of the relocation is carried in the data, and we must not
8793 // apply the static relocation.
8794
8795 template<bool big_endian>
8796 inline bool
8797 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8798     const Sized_symbol<32>* gsym,
8799     unsigned int r_type,
8800     bool is_32bit,
8801     Output_section* output_section)
8802 {
8803   // If the output section is not allocated, then we didn't call
8804   // scan_relocs, we didn't create a dynamic reloc, and we must apply
8805   // the reloc here.
8806   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8807       return true;
8808
8809   int ref_flags = Scan::get_reference_flags(r_type);
8810
8811   // For local symbols, we will have created a non-RELATIVE dynamic
8812   // relocation only if (a) the output is position independent,
8813   // (b) the relocation is absolute (not pc- or segment-relative), and
8814   // (c) the relocation is not 32 bits wide.
8815   if (gsym == NULL)
8816     return !(parameters->options().output_is_position_independent()
8817              && (ref_flags & Symbol::ABSOLUTE_REF)
8818              && !is_32bit);
8819
8820   // For global symbols, we use the same helper routines used in the
8821   // scan pass.  If we did not create a dynamic relocation, or if we
8822   // created a RELATIVE dynamic relocation, we should apply the static
8823   // relocation.
8824   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8825   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8826                  && gsym->can_use_relative_reloc(ref_flags
8827                                                  & Symbol::FUNCTION_CALL);
8828   return !has_dyn || is_rel;
8829 }
8830
8831 // Perform a relocation.
8832
8833 template<bool big_endian>
8834 inline bool
8835 Target_arm<big_endian>::Relocate::relocate(
8836     const Relocate_info<32, big_endian>* relinfo,
8837     Target_arm* target,
8838     Output_section* output_section,
8839     size_t relnum,
8840     const elfcpp::Rel<32, big_endian>& rel,
8841     unsigned int r_type,
8842     const Sized_symbol<32>* gsym,
8843     const Symbol_value<32>* psymval,
8844     unsigned char* view,
8845     Arm_address address,
8846     section_size_type view_size)
8847 {
8848   if (view == NULL)
8849     return true;
8850
8851   typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8852
8853   r_type = get_real_reloc_type(r_type);
8854   const Arm_reloc_property* reloc_property =
8855     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8856   if (reloc_property == NULL)
8857     {
8858       std::string reloc_name =
8859         arm_reloc_property_table->reloc_name_in_error_message(r_type);
8860       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8861                              _("cannot relocate %s in object file"),
8862                              reloc_name.c_str());
8863       return true;
8864     }
8865
8866   const Arm_relobj<big_endian>* object =
8867     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8868
8869   // If the final branch target of a relocation is THUMB instruction, this
8870   // is 1.  Otherwise it is 0.
8871   Arm_address thumb_bit = 0;
8872   Symbol_value<32> symval;
8873   bool is_weakly_undefined_without_plt = false;
8874   bool have_got_offset = false;
8875   unsigned int got_offset = 0;
8876
8877   // If the relocation uses the GOT entry of a symbol instead of the symbol
8878   // itself, we don't care about whether the symbol is defined or what kind
8879   // of symbol it is.
8880   if (reloc_property->uses_got_entry())
8881     {
8882       // Get the GOT offset.
8883       // The GOT pointer points to the end of the GOT section.
8884       // We need to subtract the size of the GOT section to get
8885       // the actual offset to use in the relocation.
8886       // TODO: We should move GOT offset computing code in TLS relocations
8887       // to here.
8888       switch (r_type)
8889         {
8890         case elfcpp::R_ARM_GOT_BREL:
8891         case elfcpp::R_ARM_GOT_PREL:
8892           if (gsym != NULL)
8893             {
8894               gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8895               got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8896                             - target->got_size());
8897             }
8898           else
8899             {
8900               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8901               gold_assert(object->local_has_got_offset(r_sym,
8902                                                        GOT_TYPE_STANDARD));
8903               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8904                             - target->got_size());
8905             }
8906           have_got_offset = true;
8907           break;
8908
8909         default:
8910           break;
8911         }
8912     }
8913   else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8914     {
8915       if (gsym != NULL)
8916         {
8917           // This is a global symbol.  Determine if we use PLT and if the
8918           // final target is THUMB.
8919           if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
8920             {
8921               // This uses a PLT, change the symbol value.
8922               symval.set_output_value(target->plt_section()->address()
8923                                       + gsym->plt_offset());
8924               psymval = &symval;
8925             }
8926           else if (gsym->is_weak_undefined())
8927             {
8928               // This is a weakly undefined symbol and we do not use PLT
8929               // for this relocation.  A branch targeting this symbol will
8930               // be converted into an NOP.
8931               is_weakly_undefined_without_plt = true;
8932             }
8933           else if (gsym->is_undefined() && reloc_property->uses_symbol())
8934             {
8935               // This relocation uses the symbol value but the symbol is
8936               // undefined.  Exit early and have the caller reporting an
8937               // error.
8938               return true;
8939             }
8940           else
8941             {
8942               // Set thumb bit if symbol:
8943               // -Has type STT_ARM_TFUNC or
8944               // -Has type STT_FUNC, is defined and with LSB in value set.
8945               thumb_bit =
8946                 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8947                  || (gsym->type() == elfcpp::STT_FUNC
8948                      && !gsym->is_undefined()
8949                      && ((psymval->value(object, 0) & 1) != 0)))
8950                 ? 1
8951                 : 0);
8952             }
8953         }
8954       else
8955         {
8956           // This is a local symbol.  Determine if the final target is THUMB.
8957           // We saved this information when all the local symbols were read.
8958           elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8959           unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8960           thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8961         }
8962     }
8963   else
8964     {
8965       // This is a fake relocation synthesized for a stub.  It does not have
8966       // a real symbol.  We just look at the LSB of the symbol value to
8967       // determine if the target is THUMB or not.
8968       thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8969     }
8970
8971   // Strip LSB if this points to a THUMB target.
8972   if (thumb_bit != 0
8973       && reloc_property->uses_thumb_bit()
8974       && ((psymval->value(object, 0) & 1) != 0))
8975     {
8976       Arm_address stripped_value =
8977         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8978       symval.set_output_value(stripped_value);
8979       psymval = &symval;
8980     }
8981
8982   // To look up relocation stubs, we need to pass the symbol table index of
8983   // a local symbol.
8984   unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8985
8986   // Get the addressing origin of the output segment defining the
8987   // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8988   Arm_address sym_origin = 0;
8989   if (reloc_property->uses_symbol_base())
8990     {
8991       if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8992         // R_ARM_BASE_ABS with the NULL symbol will give the
8993         // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8994         // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8995         sym_origin = target->got_plt_section()->address();
8996       else if (gsym == NULL)
8997         sym_origin = 0;
8998       else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8999         sym_origin = gsym->output_segment()->vaddr();
9000       else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
9001         sym_origin = gsym->output_data()->address();
9002
9003       // TODO: Assumes the segment base to be zero for the global symbols
9004       // till the proper support for the segment-base-relative addressing
9005       // will be implemented.  This is consistent with GNU ld.
9006     }
9007
9008   // For relative addressing relocation, find out the relative address base.
9009   Arm_address relative_address_base = 0;
9010   switch(reloc_property->relative_address_base())
9011     {
9012     case Arm_reloc_property::RAB_NONE:
9013     // Relocations with relative address bases RAB_TLS and RAB_tp are
9014     // handled by relocate_tls.  So we do not need to do anything here.
9015     case Arm_reloc_property::RAB_TLS:
9016     case Arm_reloc_property::RAB_tp:
9017       break;
9018     case Arm_reloc_property::RAB_B_S:
9019       relative_address_base = sym_origin;
9020       break;
9021     case Arm_reloc_property::RAB_GOT_ORG:
9022       relative_address_base = target->got_plt_section()->address();
9023       break;
9024     case Arm_reloc_property::RAB_P:
9025       relative_address_base = address;
9026       break;
9027     case Arm_reloc_property::RAB_Pa:
9028       relative_address_base = address & 0xfffffffcU;
9029       break;
9030     default:
9031       gold_unreachable();
9032     }
9033
9034   typename Arm_relocate_functions::Status reloc_status =
9035         Arm_relocate_functions::STATUS_OKAY;
9036   bool check_overflow = reloc_property->checks_overflow();
9037   switch (r_type)
9038     {
9039     case elfcpp::R_ARM_NONE:
9040       break;
9041
9042     case elfcpp::R_ARM_ABS8:
9043       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9044         reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
9045       break;
9046
9047     case elfcpp::R_ARM_ABS12:
9048       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9049         reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
9050       break;
9051
9052     case elfcpp::R_ARM_ABS16:
9053       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9054         reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
9055       break;
9056
9057     case elfcpp::R_ARM_ABS32:
9058       if (should_apply_static_reloc(gsym, r_type, true, output_section))
9059         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9060                                                      thumb_bit);
9061       break;
9062
9063     case elfcpp::R_ARM_ABS32_NOI:
9064       if (should_apply_static_reloc(gsym, r_type, true, output_section))
9065         // No thumb bit for this relocation: (S + A)
9066         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9067                                                      0);
9068       break;
9069
9070     case elfcpp::R_ARM_MOVW_ABS_NC:
9071       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9072         reloc_status = Arm_relocate_functions::movw(view, object, psymval,
9073                                                     0, thumb_bit,
9074                                                     check_overflow);
9075       break;
9076
9077     case elfcpp::R_ARM_MOVT_ABS:
9078       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9079         reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
9080       break;
9081
9082     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9083       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9084         reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
9085                                                         0, thumb_bit, false);
9086       break;
9087
9088     case elfcpp::R_ARM_THM_MOVT_ABS:
9089       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9090         reloc_status = Arm_relocate_functions::thm_movt(view, object,
9091                                                         psymval, 0);
9092       break;
9093
9094     case elfcpp::R_ARM_MOVW_PREL_NC:
9095     case elfcpp::R_ARM_MOVW_BREL_NC:
9096     case elfcpp::R_ARM_MOVW_BREL:
9097       reloc_status =
9098         Arm_relocate_functions::movw(view, object, psymval,
9099                                      relative_address_base, thumb_bit,
9100                                      check_overflow);
9101       break;
9102
9103     case elfcpp::R_ARM_MOVT_PREL:
9104     case elfcpp::R_ARM_MOVT_BREL:
9105       reloc_status =
9106         Arm_relocate_functions::movt(view, object, psymval,
9107                                      relative_address_base);
9108       break;
9109
9110     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9111     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9112     case elfcpp::R_ARM_THM_MOVW_BREL:
9113       reloc_status =
9114         Arm_relocate_functions::thm_movw(view, object, psymval,
9115                                          relative_address_base,
9116                                          thumb_bit, check_overflow);
9117       break;
9118
9119     case elfcpp::R_ARM_THM_MOVT_PREL:
9120     case elfcpp::R_ARM_THM_MOVT_BREL:
9121       reloc_status =
9122         Arm_relocate_functions::thm_movt(view, object, psymval,
9123                                          relative_address_base);
9124       break;
9125
9126     case elfcpp::R_ARM_REL32:
9127       reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9128                                                    address, thumb_bit);
9129       break;
9130
9131     case elfcpp::R_ARM_THM_ABS5:
9132       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9133         reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
9134       break;
9135
9136     // Thumb long branches.
9137     case elfcpp::R_ARM_THM_CALL:
9138     case elfcpp::R_ARM_THM_XPC22:
9139     case elfcpp::R_ARM_THM_JUMP24:
9140       reloc_status =
9141         Arm_relocate_functions::thumb_branch_common(
9142             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9143             thumb_bit, is_weakly_undefined_without_plt);
9144       break;
9145
9146     case elfcpp::R_ARM_GOTOFF32:
9147       {
9148         Arm_address got_origin;
9149         got_origin = target->got_plt_section()->address();
9150         reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9151                                                      got_origin, thumb_bit);
9152       }
9153       break;
9154
9155     case elfcpp::R_ARM_BASE_PREL:
9156       gold_assert(gsym != NULL);
9157       reloc_status =
9158           Arm_relocate_functions::base_prel(view, sym_origin, address);
9159       break;
9160
9161     case elfcpp::R_ARM_BASE_ABS:
9162       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9163         reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
9164       break;
9165
9166     case elfcpp::R_ARM_GOT_BREL:
9167       gold_assert(have_got_offset);
9168       reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
9169       break;
9170
9171     case elfcpp::R_ARM_GOT_PREL:
9172       gold_assert(have_got_offset);
9173       // Get the address origin for GOT PLT, which is allocated right
9174       // after the GOT section, to calculate an absolute address of
9175       // the symbol GOT entry (got_origin + got_offset).
9176       Arm_address got_origin;
9177       got_origin = target->got_plt_section()->address();
9178       reloc_status = Arm_relocate_functions::got_prel(view,
9179                                                       got_origin + got_offset,
9180                                                       address);
9181       break;
9182
9183     case elfcpp::R_ARM_PLT32:
9184     case elfcpp::R_ARM_CALL:
9185     case elfcpp::R_ARM_JUMP24:
9186     case elfcpp::R_ARM_XPC25:
9187       gold_assert(gsym == NULL
9188                   || gsym->has_plt_offset()
9189                   || gsym->final_value_is_known()
9190                   || (gsym->is_defined()
9191                       && !gsym->is_from_dynobj()
9192                       && !gsym->is_preemptible()));
9193       reloc_status =
9194         Arm_relocate_functions::arm_branch_common(
9195             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9196             thumb_bit, is_weakly_undefined_without_plt);
9197       break;
9198
9199     case elfcpp::R_ARM_THM_JUMP19:
9200       reloc_status =
9201         Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9202                                            thumb_bit);
9203       break;
9204
9205     case elfcpp::R_ARM_THM_JUMP6:
9206       reloc_status =
9207         Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9208       break;
9209
9210     case elfcpp::R_ARM_THM_JUMP8:
9211       reloc_status =
9212         Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9213       break;
9214
9215     case elfcpp::R_ARM_THM_JUMP11:
9216       reloc_status =
9217         Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9218       break;
9219
9220     case elfcpp::R_ARM_PREL31:
9221       reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9222                                                     address, thumb_bit);
9223       break;
9224
9225     case elfcpp::R_ARM_V4BX:
9226       if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9227         {
9228           const bool is_v4bx_interworking =
9229               (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9230           reloc_status =
9231             Arm_relocate_functions::v4bx(relinfo, view, object, address,
9232                                          is_v4bx_interworking);
9233         }
9234       break;
9235
9236     case elfcpp::R_ARM_THM_PC8:
9237       reloc_status =
9238         Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9239       break;
9240
9241     case elfcpp::R_ARM_THM_PC12:
9242       reloc_status =
9243         Arm_relocate_functions::thm_pc12(view, object, psymval, address);
9244       break;
9245
9246     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9247       reloc_status =
9248         Arm_relocate_functions::thm_alu11(view, object, psymval, address,
9249                                           thumb_bit);
9250       break;
9251
9252     case elfcpp::R_ARM_ALU_PC_G0_NC:
9253     case elfcpp::R_ARM_ALU_PC_G0:
9254     case elfcpp::R_ARM_ALU_PC_G1_NC:
9255     case elfcpp::R_ARM_ALU_PC_G1:
9256     case elfcpp::R_ARM_ALU_PC_G2:
9257     case elfcpp::R_ARM_ALU_SB_G0_NC:
9258     case elfcpp::R_ARM_ALU_SB_G0:
9259     case elfcpp::R_ARM_ALU_SB_G1_NC:
9260     case elfcpp::R_ARM_ALU_SB_G1:
9261     case elfcpp::R_ARM_ALU_SB_G2:
9262       reloc_status =
9263         Arm_relocate_functions::arm_grp_alu(view, object, psymval,
9264                                             reloc_property->group_index(),
9265                                             relative_address_base,
9266                                             thumb_bit, check_overflow);
9267       break;
9268
9269     case elfcpp::R_ARM_LDR_PC_G0:
9270     case elfcpp::R_ARM_LDR_PC_G1:
9271     case elfcpp::R_ARM_LDR_PC_G2:
9272     case elfcpp::R_ARM_LDR_SB_G0:
9273     case elfcpp::R_ARM_LDR_SB_G1:
9274     case elfcpp::R_ARM_LDR_SB_G2:
9275       reloc_status =
9276           Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9277                                               reloc_property->group_index(),
9278                                               relative_address_base);
9279       break;
9280
9281     case elfcpp::R_ARM_LDRS_PC_G0:
9282     case elfcpp::R_ARM_LDRS_PC_G1:
9283     case elfcpp::R_ARM_LDRS_PC_G2:
9284     case elfcpp::R_ARM_LDRS_SB_G0:
9285     case elfcpp::R_ARM_LDRS_SB_G1:
9286     case elfcpp::R_ARM_LDRS_SB_G2:
9287       reloc_status =
9288           Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9289                                                reloc_property->group_index(),
9290                                                relative_address_base);
9291       break;
9292
9293     case elfcpp::R_ARM_LDC_PC_G0:
9294     case elfcpp::R_ARM_LDC_PC_G1:
9295     case elfcpp::R_ARM_LDC_PC_G2:
9296     case elfcpp::R_ARM_LDC_SB_G0:
9297     case elfcpp::R_ARM_LDC_SB_G1:
9298     case elfcpp::R_ARM_LDC_SB_G2:
9299       reloc_status =
9300           Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9301                                               reloc_property->group_index(),
9302                                               relative_address_base);
9303       break;
9304
9305       // These are initial tls relocs, which are expected when
9306       // linking.
9307     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9308     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9309     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9310     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9311     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9312       reloc_status =
9313         this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9314                            view, address, view_size);
9315       break;
9316
9317     // The known and unknown unsupported and/or deprecated relocations.
9318     case elfcpp::R_ARM_PC24:
9319     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9320     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9321     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9322     default:
9323       // Just silently leave the method. We should get an appropriate error
9324       // message in the scan methods.
9325       break;
9326     }
9327
9328   // Report any errors.
9329   switch (reloc_status)
9330     {
9331     case Arm_relocate_functions::STATUS_OKAY:
9332       break;
9333     case Arm_relocate_functions::STATUS_OVERFLOW:
9334       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9335                              _("relocation overflow in %s"),
9336                              reloc_property->name().c_str());
9337       break;
9338     case Arm_relocate_functions::STATUS_BAD_RELOC:
9339       gold_error_at_location(
9340         relinfo,
9341         relnum,
9342         rel.get_r_offset(),
9343         _("unexpected opcode while processing relocation %s"),
9344         reloc_property->name().c_str());
9345       break;
9346     default:
9347       gold_unreachable();
9348     }
9349
9350   return true;
9351 }
9352
9353 // Perform a TLS relocation.
9354
9355 template<bool big_endian>
9356 inline typename Arm_relocate_functions<big_endian>::Status
9357 Target_arm<big_endian>::Relocate::relocate_tls(
9358     const Relocate_info<32, big_endian>* relinfo,
9359     Target_arm<big_endian>* target,
9360     size_t relnum,
9361     const elfcpp::Rel<32, big_endian>& rel,
9362     unsigned int r_type,
9363     const Sized_symbol<32>* gsym,
9364     const Symbol_value<32>* psymval,
9365     unsigned char* view,
9366     elfcpp::Elf_types<32>::Elf_Addr address,
9367     section_size_type /*view_size*/ )
9368 {
9369   typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9370   typedef Relocate_functions<32, big_endian> RelocFuncs;
9371   Output_segment* tls_segment = relinfo->layout->tls_segment();
9372
9373   const Sized_relobj_file<32, big_endian>* object = relinfo->object;
9374
9375   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9376
9377   const bool is_final = (gsym == NULL
9378                          ? !parameters->options().shared()
9379                          : gsym->final_value_is_known());
9380   const tls::Tls_optimization optimized_type
9381       = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9382   switch (r_type)
9383     {
9384     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9385         {
9386           unsigned int got_type = GOT_TYPE_TLS_PAIR;
9387           unsigned int got_offset;
9388           if (gsym != NULL)
9389             {
9390               gold_assert(gsym->has_got_offset(got_type));
9391               got_offset = gsym->got_offset(got_type) - target->got_size();
9392             }
9393           else
9394             {
9395               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9396               gold_assert(object->local_has_got_offset(r_sym, got_type));
9397               got_offset = (object->local_got_offset(r_sym, got_type)
9398                             - target->got_size());
9399             }
9400           if (optimized_type == tls::TLSOPT_NONE)
9401             {
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         }
9411       break;
9412
9413     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9414       if (optimized_type == tls::TLSOPT_NONE)
9415         {
9416           // Relocate the field with the offset of the GOT entry for
9417           // the module index.
9418           unsigned int got_offset;
9419           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9420                         - target->got_size());
9421           Arm_address got_entry =
9422             target->got_plt_section()->address() + got_offset;
9423
9424           // Relocate the field with the PC relative offset of the pair of
9425           // GOT entries.
9426           RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9427           return ArmRelocFuncs::STATUS_OKAY;
9428         }
9429       break;
9430
9431     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9432       RelocFuncs::rel32_unaligned(view, value);
9433       return ArmRelocFuncs::STATUS_OKAY;
9434
9435     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9436       if (optimized_type == tls::TLSOPT_NONE)
9437         {
9438           // Relocate the field with the offset of the GOT entry for
9439           // the tp-relative offset of the symbol.
9440           unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9441           unsigned int got_offset;
9442           if (gsym != NULL)
9443             {
9444               gold_assert(gsym->has_got_offset(got_type));
9445               got_offset = gsym->got_offset(got_type);
9446             }
9447           else
9448             {
9449               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9450               gold_assert(object->local_has_got_offset(r_sym, got_type));
9451               got_offset = object->local_got_offset(r_sym, got_type);
9452             }
9453
9454           // All GOT offsets are relative to the end of the GOT.
9455           got_offset -= target->got_size();
9456
9457           Arm_address got_entry =
9458             target->got_plt_section()->address() + got_offset;
9459
9460           // Relocate the field with the PC relative offset of the GOT entry.
9461           RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9462           return ArmRelocFuncs::STATUS_OKAY;
9463         }
9464       break;
9465
9466     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9467       // If we're creating a shared library, a dynamic relocation will
9468       // have been created for this location, so do not apply it now.
9469       if (!parameters->options().shared())
9470         {
9471           gold_assert(tls_segment != NULL);
9472
9473           // $tp points to the TCB, which is followed by the TLS, so we
9474           // need to add TCB size to the offset.
9475           Arm_address aligned_tcb_size =
9476             align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9477           RelocFuncs::rel32_unaligned(view, value + aligned_tcb_size);
9478
9479         }
9480       return ArmRelocFuncs::STATUS_OKAY;
9481
9482     default:
9483       gold_unreachable();
9484     }
9485
9486   gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9487                          _("unsupported reloc %u"),
9488                          r_type);
9489   return ArmRelocFuncs::STATUS_BAD_RELOC;
9490 }
9491
9492 // Relocate section data.
9493
9494 template<bool big_endian>
9495 void
9496 Target_arm<big_endian>::relocate_section(
9497     const Relocate_info<32, big_endian>* relinfo,
9498     unsigned int sh_type,
9499     const unsigned char* prelocs,
9500     size_t reloc_count,
9501     Output_section* output_section,
9502     bool needs_special_offset_handling,
9503     unsigned char* view,
9504     Arm_address address,
9505     section_size_type view_size,
9506     const Reloc_symbol_changes* reloc_symbol_changes)
9507 {
9508   typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
9509   gold_assert(sh_type == elfcpp::SHT_REL);
9510
9511   // See if we are relocating a relaxed input section.  If so, the view
9512   // covers the whole output section and we need to adjust accordingly.
9513   if (needs_special_offset_handling)
9514     {
9515       const Output_relaxed_input_section* poris =
9516         output_section->find_relaxed_input_section(relinfo->object,
9517                                                    relinfo->data_shndx);
9518       if (poris != NULL)
9519         {
9520           Arm_address section_address = poris->address();
9521           section_size_type section_size = poris->data_size();
9522
9523           gold_assert((section_address >= address)
9524                       && ((section_address + section_size)
9525                           <= (address + view_size)));
9526
9527           off_t offset = section_address - address;
9528           view += offset;
9529           address += offset;
9530           view_size = section_size;
9531         }
9532     }
9533
9534   gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
9535                          Arm_relocate, gold::Default_comdat_behavior>(
9536     relinfo,
9537     this,
9538     prelocs,
9539     reloc_count,
9540     output_section,
9541     needs_special_offset_handling,
9542     view,
9543     address,
9544     view_size,
9545     reloc_symbol_changes);
9546 }
9547
9548 // Return the size of a relocation while scanning during a relocatable
9549 // link.
9550
9551 template<bool big_endian>
9552 unsigned int
9553 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
9554     unsigned int r_type,
9555     Relobj* object)
9556 {
9557   r_type = get_real_reloc_type(r_type);
9558   const Arm_reloc_property* arp =
9559       arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9560   if (arp != NULL)
9561     return arp->size();
9562   else
9563     {
9564       std::string reloc_name =
9565         arm_reloc_property_table->reloc_name_in_error_message(r_type);
9566       gold_error(_("%s: unexpected %s in object file"),
9567                  object->name().c_str(), reloc_name.c_str());
9568       return 0;
9569     }
9570 }
9571
9572 // Scan the relocs during a relocatable link.
9573
9574 template<bool big_endian>
9575 void
9576 Target_arm<big_endian>::scan_relocatable_relocs(
9577     Symbol_table* symtab,
9578     Layout* layout,
9579     Sized_relobj_file<32, big_endian>* object,
9580     unsigned int data_shndx,
9581     unsigned int sh_type,
9582     const unsigned char* prelocs,
9583     size_t reloc_count,
9584     Output_section* output_section,
9585     bool needs_special_offset_handling,
9586     size_t local_symbol_count,
9587     const unsigned char* plocal_symbols,
9588     Relocatable_relocs* rr)
9589 {
9590   gold_assert(sh_type == elfcpp::SHT_REL);
9591
9592   typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
9593     Relocatable_size_for_reloc> Scan_relocatable_relocs;
9594
9595   gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
9596       Scan_relocatable_relocs>(
9597     symtab,
9598     layout,
9599     object,
9600     data_shndx,
9601     prelocs,
9602     reloc_count,
9603     output_section,
9604     needs_special_offset_handling,
9605     local_symbol_count,
9606     plocal_symbols,
9607     rr);
9608 }
9609
9610 // Emit relocations for a section.
9611
9612 template<bool big_endian>
9613 void
9614 Target_arm<big_endian>::relocate_relocs(
9615     const Relocate_info<32, big_endian>* relinfo,
9616     unsigned int sh_type,
9617     const unsigned char* prelocs,
9618     size_t reloc_count,
9619     Output_section* output_section,
9620     typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
9621     const Relocatable_relocs* rr,
9622     unsigned char* view,
9623     Arm_address view_address,
9624     section_size_type view_size,
9625     unsigned char* reloc_view,
9626     section_size_type reloc_view_size)
9627 {
9628   gold_assert(sh_type == elfcpp::SHT_REL);
9629
9630   gold::relocate_relocs<32, big_endian, elfcpp::SHT_REL>(
9631     relinfo,
9632     prelocs,
9633     reloc_count,
9634     output_section,
9635     offset_in_output_section,
9636     rr,
9637     view,
9638     view_address,
9639     view_size,
9640     reloc_view,
9641     reloc_view_size);
9642 }
9643
9644 // Perform target-specific processing in a relocatable link.  This is
9645 // only used if we use the relocation strategy RELOC_SPECIAL.
9646
9647 template<bool big_endian>
9648 void
9649 Target_arm<big_endian>::relocate_special_relocatable(
9650     const Relocate_info<32, big_endian>* relinfo,
9651     unsigned int sh_type,
9652     const unsigned char* preloc_in,
9653     size_t relnum,
9654     Output_section* output_section,
9655     typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
9656     unsigned char* view,
9657     elfcpp::Elf_types<32>::Elf_Addr view_address,
9658     section_size_type,
9659     unsigned char* preloc_out)
9660 {
9661   // We can only handle REL type relocation sections.
9662   gold_assert(sh_type == elfcpp::SHT_REL);
9663
9664   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
9665   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
9666     Reltype_write;
9667   const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
9668
9669   const Arm_relobj<big_endian>* object =
9670     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9671   const unsigned int local_count = object->local_symbol_count();
9672
9673   Reltype reloc(preloc_in);
9674   Reltype_write reloc_write(preloc_out);
9675
9676   elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
9677   const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9678   const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
9679
9680   const Arm_reloc_property* arp =
9681     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9682   gold_assert(arp != NULL);
9683
9684   // Get the new symbol index.
9685   // We only use RELOC_SPECIAL strategy in local relocations.
9686   gold_assert(r_sym < local_count);
9687
9688   // We are adjusting a section symbol.  We need to find
9689   // the symbol table index of the section symbol for
9690   // the output section corresponding to input section
9691   // in which this symbol is defined.
9692   bool is_ordinary;
9693   unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
9694   gold_assert(is_ordinary);
9695   Output_section* os = object->output_section(shndx);
9696   gold_assert(os != NULL);
9697   gold_assert(os->needs_symtab_index());
9698   unsigned int new_symndx = os->symtab_index();
9699
9700   // Get the new offset--the location in the output section where
9701   // this relocation should be applied.
9702
9703   Arm_address offset = reloc.get_r_offset();
9704   Arm_address new_offset;
9705   if (offset_in_output_section != invalid_address)
9706     new_offset = offset + offset_in_output_section;
9707   else
9708     {
9709       section_offset_type sot_offset =
9710           convert_types<section_offset_type, Arm_address>(offset);
9711       section_offset_type new_sot_offset =
9712           output_section->output_offset(object, relinfo->data_shndx,
9713                                         sot_offset);
9714       gold_assert(new_sot_offset != -1);
9715       new_offset = new_sot_offset;
9716     }
9717
9718   // In an object file, r_offset is an offset within the section.
9719   // In an executable or dynamic object, generated by
9720   // --emit-relocs, r_offset is an absolute address.
9721   if (!parameters->options().relocatable())
9722     {
9723       new_offset += view_address;
9724       if (offset_in_output_section != invalid_address)
9725         new_offset -= offset_in_output_section;
9726     }
9727
9728   reloc_write.put_r_offset(new_offset);
9729   reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
9730
9731   // Handle the reloc addend.
9732   // The relocation uses a section symbol in the input file.
9733   // We are adjusting it to use a section symbol in the output
9734   // file.  The input section symbol refers to some address in
9735   // the input section.  We need the relocation in the output
9736   // file to refer to that same address.  This adjustment to
9737   // the addend is the same calculation we use for a simple
9738   // absolute relocation for the input section symbol.
9739
9740   const Symbol_value<32>* psymval = object->local_symbol(r_sym);
9741
9742   // Handle THUMB bit.
9743   Symbol_value<32> symval;
9744   Arm_address thumb_bit =
9745      object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9746   if (thumb_bit != 0
9747       && arp->uses_thumb_bit()
9748       && ((psymval->value(object, 0) & 1) != 0))
9749     {
9750       Arm_address stripped_value =
9751         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9752       symval.set_output_value(stripped_value);
9753       psymval = &symval;
9754     }
9755
9756   unsigned char* paddend = view + offset;
9757   typename Arm_relocate_functions<big_endian>::Status reloc_status =
9758         Arm_relocate_functions<big_endian>::STATUS_OKAY;
9759   switch (r_type)
9760     {
9761     case elfcpp::R_ARM_ABS8:
9762       reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
9763                                                               psymval);
9764       break;
9765
9766     case elfcpp::R_ARM_ABS12:
9767       reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
9768                                                                psymval);
9769       break;
9770
9771     case elfcpp::R_ARM_ABS16:
9772       reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
9773                                                                psymval);
9774       break;
9775
9776     case elfcpp::R_ARM_THM_ABS5:
9777       reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
9778                                                                   object,
9779                                                                   psymval);
9780       break;
9781
9782     case elfcpp::R_ARM_MOVW_ABS_NC:
9783     case elfcpp::R_ARM_MOVW_PREL_NC:
9784     case elfcpp::R_ARM_MOVW_BREL_NC:
9785     case elfcpp::R_ARM_MOVW_BREL:
9786       reloc_status = Arm_relocate_functions<big_endian>::movw(
9787           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9788       break;
9789
9790     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9791     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9792     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9793     case elfcpp::R_ARM_THM_MOVW_BREL:
9794       reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
9795           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9796       break;
9797
9798     case elfcpp::R_ARM_THM_CALL:
9799     case elfcpp::R_ARM_THM_XPC22:
9800     case elfcpp::R_ARM_THM_JUMP24:
9801       reloc_status =
9802         Arm_relocate_functions<big_endian>::thumb_branch_common(
9803             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9804             false);
9805       break;
9806
9807     case elfcpp::R_ARM_PLT32:
9808     case elfcpp::R_ARM_CALL:
9809     case elfcpp::R_ARM_JUMP24:
9810     case elfcpp::R_ARM_XPC25:
9811       reloc_status =
9812         Arm_relocate_functions<big_endian>::arm_branch_common(
9813             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9814             false);
9815       break;
9816
9817     case elfcpp::R_ARM_THM_JUMP19:
9818       reloc_status =
9819         Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
9820                                                        psymval, 0, thumb_bit);
9821       break;
9822
9823     case elfcpp::R_ARM_THM_JUMP6:
9824       reloc_status =
9825         Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
9826                                                       0);
9827       break;
9828
9829     case elfcpp::R_ARM_THM_JUMP8:
9830       reloc_status =
9831         Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
9832                                                       0);
9833       break;
9834
9835     case elfcpp::R_ARM_THM_JUMP11:
9836       reloc_status =
9837         Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
9838                                                        0);
9839       break;
9840
9841     case elfcpp::R_ARM_PREL31:
9842       reloc_status =
9843         Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
9844                                                    thumb_bit);
9845       break;
9846
9847     case elfcpp::R_ARM_THM_PC8:
9848       reloc_status =
9849         Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
9850                                                     0);
9851       break;
9852
9853     case elfcpp::R_ARM_THM_PC12:
9854       reloc_status =
9855         Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
9856                                                      0);
9857       break;
9858
9859     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9860       reloc_status =
9861         Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
9862                                                       0, thumb_bit);
9863       break;
9864
9865     // These relocation truncate relocation results so we cannot handle them
9866     // in a relocatable link.
9867     case elfcpp::R_ARM_MOVT_ABS:
9868     case elfcpp::R_ARM_THM_MOVT_ABS:
9869     case elfcpp::R_ARM_MOVT_PREL:
9870     case elfcpp::R_ARM_MOVT_BREL:
9871     case elfcpp::R_ARM_THM_MOVT_PREL:
9872     case elfcpp::R_ARM_THM_MOVT_BREL:
9873     case elfcpp::R_ARM_ALU_PC_G0_NC:
9874     case elfcpp::R_ARM_ALU_PC_G0:
9875     case elfcpp::R_ARM_ALU_PC_G1_NC:
9876     case elfcpp::R_ARM_ALU_PC_G1:
9877     case elfcpp::R_ARM_ALU_PC_G2:
9878     case elfcpp::R_ARM_ALU_SB_G0_NC:
9879     case elfcpp::R_ARM_ALU_SB_G0:
9880     case elfcpp::R_ARM_ALU_SB_G1_NC:
9881     case elfcpp::R_ARM_ALU_SB_G1:
9882     case elfcpp::R_ARM_ALU_SB_G2:
9883     case elfcpp::R_ARM_LDR_PC_G0:
9884     case elfcpp::R_ARM_LDR_PC_G1:
9885     case elfcpp::R_ARM_LDR_PC_G2:
9886     case elfcpp::R_ARM_LDR_SB_G0:
9887     case elfcpp::R_ARM_LDR_SB_G1:
9888     case elfcpp::R_ARM_LDR_SB_G2:
9889     case elfcpp::R_ARM_LDRS_PC_G0:
9890     case elfcpp::R_ARM_LDRS_PC_G1:
9891     case elfcpp::R_ARM_LDRS_PC_G2:
9892     case elfcpp::R_ARM_LDRS_SB_G0:
9893     case elfcpp::R_ARM_LDRS_SB_G1:
9894     case elfcpp::R_ARM_LDRS_SB_G2:
9895     case elfcpp::R_ARM_LDC_PC_G0:
9896     case elfcpp::R_ARM_LDC_PC_G1:
9897     case elfcpp::R_ARM_LDC_PC_G2:
9898     case elfcpp::R_ARM_LDC_SB_G0:
9899     case elfcpp::R_ARM_LDC_SB_G1:
9900     case elfcpp::R_ARM_LDC_SB_G2:
9901       gold_error(_("cannot handle %s in a relocatable link"),
9902                  arp->name().c_str());
9903       break;
9904
9905     default:
9906       gold_unreachable();
9907     }
9908
9909   // Report any errors.
9910   switch (reloc_status)
9911     {
9912     case Arm_relocate_functions<big_endian>::STATUS_OKAY:
9913       break;
9914     case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
9915       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9916                              _("relocation overflow in %s"),
9917                              arp->name().c_str());
9918       break;
9919     case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
9920       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9921         _("unexpected opcode while processing relocation %s"),
9922         arp->name().c_str());
9923       break;
9924     default:
9925       gold_unreachable();
9926     }
9927 }
9928
9929 // Return the value to use for a dynamic symbol which requires special
9930 // treatment.  This is how we support equality comparisons of function
9931 // pointers across shared library boundaries, as described in the
9932 // processor specific ABI supplement.
9933
9934 template<bool big_endian>
9935 uint64_t
9936 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
9937 {
9938   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
9939   return this->plt_section()->address() + gsym->plt_offset();
9940 }
9941
9942 // Map platform-specific relocs to real relocs
9943 //
9944 template<bool big_endian>
9945 unsigned int
9946 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
9947 {
9948   switch (r_type)
9949     {
9950     case elfcpp::R_ARM_TARGET1:
9951       // This is either R_ARM_ABS32 or R_ARM_REL32;
9952       return elfcpp::R_ARM_ABS32;
9953
9954     case elfcpp::R_ARM_TARGET2:
9955       // This can be any reloc type but usually is R_ARM_GOT_PREL
9956       return elfcpp::R_ARM_GOT_PREL;
9957
9958     default:
9959       return r_type;
9960     }
9961 }
9962
9963 // Whether if two EABI versions V1 and V2 are compatible.
9964
9965 template<bool big_endian>
9966 bool
9967 Target_arm<big_endian>::are_eabi_versions_compatible(
9968     elfcpp::Elf_Word v1,
9969     elfcpp::Elf_Word v2)
9970 {
9971   // v4 and v5 are the same spec before and after it was released,
9972   // so allow mixing them.
9973   if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
9974       || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
9975       || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
9976     return true;
9977
9978   return v1 == v2;
9979 }
9980
9981 // Combine FLAGS from an input object called NAME and the processor-specific
9982 // flags in the ELF header of the output.  Much of this is adapted from the
9983 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
9984 // in bfd/elf32-arm.c.
9985
9986 template<bool big_endian>
9987 void
9988 Target_arm<big_endian>::merge_processor_specific_flags(
9989     const std::string& name,
9990     elfcpp::Elf_Word flags)
9991 {
9992   if (this->are_processor_specific_flags_set())
9993     {
9994       elfcpp::Elf_Word out_flags = this->processor_specific_flags();
9995
9996       // Nothing to merge if flags equal to those in output.
9997       if (flags == out_flags)
9998         return;
9999
10000       // Complain about various flag mismatches.
10001       elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
10002       elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
10003       if (!this->are_eabi_versions_compatible(version1, version2)
10004           && parameters->options().warn_mismatch())
10005         gold_error(_("Source object %s has EABI version %d but output has "
10006                      "EABI version %d."),
10007                    name.c_str(),
10008                    (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
10009                    (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
10010     }
10011   else
10012     {
10013       // If the input is the default architecture and had the default
10014       // flags then do not bother setting the flags for the output
10015       // architecture, instead allow future merges to do this.  If no
10016       // future merges ever set these flags then they will retain their
10017       // uninitialised values, which surprise surprise, correspond
10018       // to the default values.
10019       if (flags == 0)
10020         return;
10021
10022       // This is the first time, just copy the flags.
10023       // We only copy the EABI version for now.
10024       this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
10025     }
10026 }
10027
10028 // Adjust ELF file header.
10029 template<bool big_endian>
10030 void
10031 Target_arm<big_endian>::do_adjust_elf_header(
10032     unsigned char* view,
10033     int len)
10034 {
10035   gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
10036
10037   elfcpp::Ehdr<32, big_endian> ehdr(view);
10038   elfcpp::Elf_Word flags = this->processor_specific_flags();
10039   unsigned char e_ident[elfcpp::EI_NIDENT];
10040   memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
10041
10042   if (elfcpp::arm_eabi_version(flags)
10043       == elfcpp::EF_ARM_EABI_UNKNOWN)
10044     e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
10045   else
10046     e_ident[elfcpp::EI_OSABI] = 0;
10047   e_ident[elfcpp::EI_ABIVERSION] = 0;
10048
10049   // FIXME: Do EF_ARM_BE8 adjustment.
10050
10051   // If we're working in EABI_VER5, set the hard/soft float ABI flags
10052   // as appropriate.
10053   if (elfcpp::arm_eabi_version(flags) == elfcpp::EF_ARM_EABI_VER5)
10054   {
10055     elfcpp::Elf_Half type = ehdr.get_e_type();
10056     if (type == elfcpp::ET_EXEC || type == elfcpp::ET_DYN)
10057       {
10058         Object_attribute* attr = this->get_aeabi_object_attribute(elfcpp::Tag_ABI_VFP_args);
10059         if (attr->int_value())
10060           flags |= elfcpp::EF_ARM_ABI_FLOAT_HARD;
10061         else
10062           flags |= elfcpp::EF_ARM_ABI_FLOAT_SOFT;
10063         this->set_processor_specific_flags(flags);
10064       }
10065   }
10066   elfcpp::Ehdr_write<32, big_endian> oehdr(view);
10067   oehdr.put_e_ident(e_ident);
10068 }
10069
10070 // do_make_elf_object to override the same function in the base class.
10071 // We need to use a target-specific sub-class of
10072 // Sized_relobj_file<32, big_endian> to store ARM specific information.
10073 // Hence we need to have our own ELF object creation.
10074
10075 template<bool big_endian>
10076 Object*
10077 Target_arm<big_endian>::do_make_elf_object(
10078     const std::string& name,
10079     Input_file* input_file,
10080     off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
10081 {
10082   int et = ehdr.get_e_type();
10083   // ET_EXEC files are valid input for --just-symbols/-R,
10084   // and we treat them as relocatable objects.
10085   if (et == elfcpp::ET_REL
10086       || (et == elfcpp::ET_EXEC && input_file->just_symbols()))
10087     {
10088       Arm_relobj<big_endian>* obj =
10089         new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
10090       obj->setup();
10091       return obj;
10092     }
10093   else if (et == elfcpp::ET_DYN)
10094     {
10095       Sized_dynobj<32, big_endian>* obj =
10096         new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
10097       obj->setup();
10098       return obj;
10099     }
10100   else
10101     {
10102       gold_error(_("%s: unsupported ELF file type %d"),
10103                  name.c_str(), et);
10104       return NULL;
10105     }
10106 }
10107
10108 // Read the architecture from the Tag_also_compatible_with attribute, if any.
10109 // Returns -1 if no architecture could be read.
10110 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
10111
10112 template<bool big_endian>
10113 int
10114 Target_arm<big_endian>::get_secondary_compatible_arch(
10115     const Attributes_section_data* pasd)
10116 {
10117   const Object_attribute* known_attributes =
10118     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10119
10120   // Note: the tag and its argument below are uleb128 values, though
10121   // currently-defined values fit in one byte for each.
10122   const std::string& sv =
10123     known_attributes[elfcpp::Tag_also_compatible_with].string_value();
10124   if (sv.size() == 2
10125       && sv.data()[0] == elfcpp::Tag_CPU_arch
10126       && (sv.data()[1] & 128) != 128)
10127    return sv.data()[1];
10128
10129   // This tag is "safely ignorable", so don't complain if it looks funny.
10130   return -1;
10131 }
10132
10133 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10134 // The tag is removed if ARCH is -1.
10135 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10136
10137 template<bool big_endian>
10138 void
10139 Target_arm<big_endian>::set_secondary_compatible_arch(
10140     Attributes_section_data* pasd,
10141     int arch)
10142 {
10143   Object_attribute* known_attributes =
10144     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10145
10146   if (arch == -1)
10147     {
10148       known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10149       return;
10150     }
10151
10152   // Note: the tag and its argument below are uleb128 values, though
10153   // currently-defined values fit in one byte for each.
10154   char sv[3];
10155   sv[0] = elfcpp::Tag_CPU_arch;
10156   gold_assert(arch != 0);
10157   sv[1] = arch;
10158   sv[2] = '\0';
10159
10160   known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10161 }
10162
10163 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10164 // into account.
10165 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10166
10167 template<bool big_endian>
10168 int
10169 Target_arm<big_endian>::tag_cpu_arch_combine(
10170     const char* name,
10171     int oldtag,
10172     int* secondary_compat_out,
10173     int newtag,
10174     int secondary_compat)
10175 {
10176 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10177   static const int v6t2[] =
10178     {
10179       T(V6T2),   // PRE_V4.
10180       T(V6T2),   // V4.
10181       T(V6T2),   // V4T.
10182       T(V6T2),   // V5T.
10183       T(V6T2),   // V5TE.
10184       T(V6T2),   // V5TEJ.
10185       T(V6T2),   // V6.
10186       T(V7),     // V6KZ.
10187       T(V6T2)    // V6T2.
10188     };
10189   static const int v6k[] =
10190     {
10191       T(V6K),    // PRE_V4.
10192       T(V6K),    // V4.
10193       T(V6K),    // V4T.
10194       T(V6K),    // V5T.
10195       T(V6K),    // V5TE.
10196       T(V6K),    // V5TEJ.
10197       T(V6K),    // V6.
10198       T(V6KZ),   // V6KZ.
10199       T(V7),     // V6T2.
10200       T(V6K)     // V6K.
10201     };
10202   static const int v7[] =
10203     {
10204       T(V7),     // PRE_V4.
10205       T(V7),     // V4.
10206       T(V7),     // V4T.
10207       T(V7),     // V5T.
10208       T(V7),     // V5TE.
10209       T(V7),     // V5TEJ.
10210       T(V7),     // V6.
10211       T(V7),     // V6KZ.
10212       T(V7),     // V6T2.
10213       T(V7),     // V6K.
10214       T(V7)      // V7.
10215     };
10216   static const int v6_m[] =
10217     {
10218       -1,        // PRE_V4.
10219       -1,        // V4.
10220       T(V6K),    // V4T.
10221       T(V6K),    // V5T.
10222       T(V6K),    // V5TE.
10223       T(V6K),    // V5TEJ.
10224       T(V6K),    // V6.
10225       T(V6KZ),   // V6KZ.
10226       T(V7),     // V6T2.
10227       T(V6K),    // V6K.
10228       T(V7),     // V7.
10229       T(V6_M)    // V6_M.
10230     };
10231   static const int v6s_m[] =
10232     {
10233       -1,        // PRE_V4.
10234       -1,        // V4.
10235       T(V6K),    // V4T.
10236       T(V6K),    // V5T.
10237       T(V6K),    // V5TE.
10238       T(V6K),    // V5TEJ.
10239       T(V6K),    // V6.
10240       T(V6KZ),   // V6KZ.
10241       T(V7),     // V6T2.
10242       T(V6K),    // V6K.
10243       T(V7),     // V7.
10244       T(V6S_M),  // V6_M.
10245       T(V6S_M)   // V6S_M.
10246     };
10247   static const int v7e_m[] =
10248     {
10249       -1,       // PRE_V4.
10250       -1,       // V4.
10251       T(V7E_M), // V4T.
10252       T(V7E_M), // V5T.
10253       T(V7E_M), // V5TE.
10254       T(V7E_M), // V5TEJ.
10255       T(V7E_M), // V6.
10256       T(V7E_M), // V6KZ.
10257       T(V7E_M), // V6T2.
10258       T(V7E_M), // V6K.
10259       T(V7E_M), // V7.
10260       T(V7E_M), // V6_M.
10261       T(V7E_M), // V6S_M.
10262       T(V7E_M)  // V7E_M.
10263     };
10264   static const int v4t_plus_v6_m[] =
10265     {
10266       -1,               // PRE_V4.
10267       -1,               // V4.
10268       T(V4T),           // V4T.
10269       T(V5T),           // V5T.
10270       T(V5TE),          // V5TE.
10271       T(V5TEJ),         // V5TEJ.
10272       T(V6),            // V6.
10273       T(V6KZ),          // V6KZ.
10274       T(V6T2),          // V6T2.
10275       T(V6K),           // V6K.
10276       T(V7),            // V7.
10277       T(V6_M),          // V6_M.
10278       T(V6S_M),         // V6S_M.
10279       T(V7E_M),         // V7E_M.
10280       T(V4T_PLUS_V6_M)  // V4T plus V6_M.
10281     };
10282   static const int* comb[] =
10283     {
10284       v6t2,
10285       v6k,
10286       v7,
10287       v6_m,
10288       v6s_m,
10289       v7e_m,
10290       // Pseudo-architecture.
10291       v4t_plus_v6_m
10292     };
10293
10294   // Check we've not got a higher architecture than we know about.
10295
10296   if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
10297     {
10298       gold_error(_("%s: unknown CPU architecture"), name);
10299       return -1;
10300     }
10301
10302   // Override old tag if we have a Tag_also_compatible_with on the output.
10303
10304   if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10305       || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10306     oldtag = T(V4T_PLUS_V6_M);
10307
10308   // And override the new tag if we have a Tag_also_compatible_with on the
10309   // input.
10310
10311   if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10312       || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10313     newtag = T(V4T_PLUS_V6_M);
10314
10315   // Architectures before V6KZ add features monotonically.
10316   int tagh = std::max(oldtag, newtag);
10317   if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10318     return tagh;
10319
10320   int tagl = std::min(oldtag, newtag);
10321   int result = comb[tagh - T(V6T2)][tagl];
10322
10323   // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10324   // as the canonical version.
10325   if (result == T(V4T_PLUS_V6_M))
10326     {
10327       result = T(V4T);
10328       *secondary_compat_out = T(V6_M);
10329     }
10330   else
10331     *secondary_compat_out = -1;
10332
10333   if (result == -1)
10334     {
10335       gold_error(_("%s: conflicting CPU architectures %d/%d"),
10336                  name, oldtag, newtag);
10337       return -1;
10338     }
10339
10340   return result;
10341 #undef T
10342 }
10343
10344 // Helper to print AEABI enum tag value.
10345
10346 template<bool big_endian>
10347 std::string
10348 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10349 {
10350   static const char* aeabi_enum_names[] =
10351     { "", "variable-size", "32-bit", "" };
10352   const size_t aeabi_enum_names_size =
10353     sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10354
10355   if (value < aeabi_enum_names_size)
10356     return std::string(aeabi_enum_names[value]);
10357   else
10358     {
10359       char buffer[100];
10360       sprintf(buffer, "<unknown value %u>", value);
10361       return std::string(buffer);
10362     }
10363 }
10364
10365 // Return the string value to store in TAG_CPU_name.
10366
10367 template<bool big_endian>
10368 std::string
10369 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10370 {
10371   static const char* name_table[] = {
10372     // These aren't real CPU names, but we can't guess
10373     // that from the architecture version alone.
10374    "Pre v4",
10375    "ARM v4",
10376    "ARM v4T",
10377    "ARM v5T",
10378    "ARM v5TE",
10379    "ARM v5TEJ",
10380    "ARM v6",
10381    "ARM v6KZ",
10382    "ARM v6T2",
10383    "ARM v6K",
10384    "ARM v7",
10385    "ARM v6-M",
10386    "ARM v6S-M",
10387    "ARM v7E-M"
10388  };
10389  const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10390
10391   if (value < name_table_size)
10392     return std::string(name_table[value]);
10393   else
10394     {
10395       char buffer[100];
10396       sprintf(buffer, "<unknown CPU value %u>", value);
10397       return std::string(buffer);
10398     }
10399 }
10400
10401 // Query attributes object to see if integer divide instructions may be
10402 // present in an object.
10403
10404 template<bool big_endian>
10405 bool
10406 Target_arm<big_endian>::attributes_accept_div(int arch, int profile,
10407     const Object_attribute* div_attr)
10408 {
10409   switch (div_attr->int_value())
10410     {
10411     case 0:
10412       // Integer divide allowed if instruction contained in
10413       // archetecture.
10414       if (arch == elfcpp::TAG_CPU_ARCH_V7 && (profile == 'R' || profile == 'M'))
10415         return true;
10416       else if (arch >= elfcpp::TAG_CPU_ARCH_V7E_M)
10417         return true;
10418       else
10419         return false;
10420
10421     case 1:
10422       // Integer divide explicitly prohibited.
10423       return false;
10424
10425     default:
10426       // Unrecognised case - treat as allowing divide everywhere.
10427     case 2:
10428       // Integer divide allowed in ARM state.
10429       return true;
10430     }
10431 }
10432
10433 // Query attributes object to see if integer divide instructions are
10434 // forbidden to be in the object.  This is not the inverse of
10435 // attributes_accept_div.
10436
10437 template<bool big_endian>
10438 bool
10439 Target_arm<big_endian>::attributes_forbid_div(const Object_attribute* div_attr)
10440 {
10441   return div_attr->int_value() == 1;
10442 }
10443
10444 // Merge object attributes from input file called NAME with those of the
10445 // output.  The input object attributes are in the object pointed by PASD.
10446
10447 template<bool big_endian>
10448 void
10449 Target_arm<big_endian>::merge_object_attributes(
10450     const char* name,
10451     const Attributes_section_data* pasd)
10452 {
10453   // Return if there is no attributes section data.
10454   if (pasd == NULL)
10455     return;
10456
10457   // If output has no object attributes, just copy.
10458   const int vendor = Object_attribute::OBJ_ATTR_PROC;
10459   if (this->attributes_section_data_ == NULL)
10460     {
10461       this->attributes_section_data_ = new Attributes_section_data(*pasd);
10462       Object_attribute* out_attr =
10463         this->attributes_section_data_->known_attributes(vendor);
10464
10465       // We do not output objects with Tag_MPextension_use_legacy - we move
10466       //  the attribute's value to Tag_MPextension_use.  */
10467       if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10468         {
10469           if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10470               && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10471                 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10472             {
10473               gold_error(_("%s has both the current and legacy "
10474                            "Tag_MPextension_use attributes"),
10475                          name);
10476             }
10477
10478           out_attr[elfcpp::Tag_MPextension_use] =
10479             out_attr[elfcpp::Tag_MPextension_use_legacy];
10480           out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10481           out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10482         }
10483
10484       return;
10485     }
10486
10487   const Object_attribute* in_attr = pasd->known_attributes(vendor);
10488   Object_attribute* out_attr =
10489     this->attributes_section_data_->known_attributes(vendor);
10490
10491   // This needs to happen before Tag_ABI_FP_number_model is merged.  */
10492   if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10493       != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
10494     {
10495       // Ignore mismatches if the object doesn't use floating point.  */
10496       if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
10497         out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10498             in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10499       else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
10500                && parameters->options().warn_mismatch())
10501         gold_error(_("%s uses VFP register arguments, output does not"),
10502                    name);
10503     }
10504
10505   for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10506     {
10507       // Merge this attribute with existing attributes.
10508       switch (i)
10509         {
10510         case elfcpp::Tag_CPU_raw_name:
10511         case elfcpp::Tag_CPU_name:
10512           // These are merged after Tag_CPU_arch.
10513           break;
10514
10515         case elfcpp::Tag_ABI_optimization_goals:
10516         case elfcpp::Tag_ABI_FP_optimization_goals:
10517           // Use the first value seen.
10518           break;
10519
10520         case elfcpp::Tag_CPU_arch:
10521           {
10522             unsigned int saved_out_attr = out_attr->int_value();
10523             // Merge Tag_CPU_arch and Tag_also_compatible_with.
10524             int secondary_compat =
10525               this->get_secondary_compatible_arch(pasd);
10526             int secondary_compat_out =
10527               this->get_secondary_compatible_arch(
10528                   this->attributes_section_data_);
10529             out_attr[i].set_int_value(
10530                 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10531                                      &secondary_compat_out,
10532                                      in_attr[i].int_value(),
10533                                      secondary_compat));
10534             this->set_secondary_compatible_arch(this->attributes_section_data_,
10535                                                 secondary_compat_out);
10536
10537             // Merge Tag_CPU_name and Tag_CPU_raw_name.
10538             if (out_attr[i].int_value() == saved_out_attr)
10539               ; // Leave the names alone.
10540             else if (out_attr[i].int_value() == in_attr[i].int_value())
10541               {
10542                 // The output architecture has been changed to match the
10543                 // input architecture.  Use the input names.
10544                 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10545                     in_attr[elfcpp::Tag_CPU_name].string_value());
10546                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10547                     in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10548               }
10549             else
10550               {
10551                 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10552                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10553               }
10554
10555             // If we still don't have a value for Tag_CPU_name,
10556             // make one up now.  Tag_CPU_raw_name remains blank.
10557             if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10558               {
10559                 const std::string cpu_name =
10560                   this->tag_cpu_name_value(out_attr[i].int_value());
10561                 // FIXME:  If we see an unknown CPU, this will be set
10562                 // to "<unknown CPU n>", where n is the attribute value.
10563                 // This is different from BFD, which leaves the name alone.
10564                 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10565               }
10566           }
10567           break;
10568
10569         case elfcpp::Tag_ARM_ISA_use:
10570         case elfcpp::Tag_THUMB_ISA_use:
10571         case elfcpp::Tag_WMMX_arch:
10572         case elfcpp::Tag_Advanced_SIMD_arch:
10573           // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10574         case elfcpp::Tag_ABI_FP_rounding:
10575         case elfcpp::Tag_ABI_FP_exceptions:
10576         case elfcpp::Tag_ABI_FP_user_exceptions:
10577         case elfcpp::Tag_ABI_FP_number_model:
10578         case elfcpp::Tag_VFP_HP_extension:
10579         case elfcpp::Tag_CPU_unaligned_access:
10580         case elfcpp::Tag_T2EE_use:
10581         case elfcpp::Tag_Virtualization_use:
10582         case elfcpp::Tag_MPextension_use:
10583           // Use the largest value specified.
10584           if (in_attr[i].int_value() > out_attr[i].int_value())
10585             out_attr[i].set_int_value(in_attr[i].int_value());
10586           break;
10587
10588         case elfcpp::Tag_ABI_align8_preserved:
10589         case elfcpp::Tag_ABI_PCS_RO_data:
10590           // Use the smallest value specified.
10591           if (in_attr[i].int_value() < out_attr[i].int_value())
10592             out_attr[i].set_int_value(in_attr[i].int_value());
10593           break;
10594
10595         case elfcpp::Tag_ABI_align8_needed:
10596           if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10597               && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10598                   || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10599                       == 0)))
10600             {
10601               // This error message should be enabled once all non-conforming
10602               // binaries in the toolchain have had the attributes set
10603               // properly.
10604               // gold_error(_("output 8-byte data alignment conflicts with %s"),
10605               //            name);
10606             }
10607           // Fall through.
10608         case elfcpp::Tag_ABI_FP_denormal:
10609         case elfcpp::Tag_ABI_PCS_GOT_use:
10610           {
10611             // These tags have 0 = don't care, 1 = strong requirement,
10612             // 2 = weak requirement.
10613             static const int order_021[3] = {0, 2, 1};
10614
10615             // Use the "greatest" from the sequence 0, 2, 1, or the largest
10616             // value if greater than 2 (for future-proofing).
10617             if ((in_attr[i].int_value() > 2
10618                  && in_attr[i].int_value() > out_attr[i].int_value())
10619                 || (in_attr[i].int_value() <= 2
10620                     && out_attr[i].int_value() <= 2
10621                     && (order_021[in_attr[i].int_value()]
10622                         > order_021[out_attr[i].int_value()])))
10623               out_attr[i].set_int_value(in_attr[i].int_value());
10624           }
10625           break;
10626
10627         case elfcpp::Tag_CPU_arch_profile:
10628           if (out_attr[i].int_value() != in_attr[i].int_value())
10629             {
10630               // 0 will merge with anything.
10631               // 'A' and 'S' merge to 'A'.
10632               // 'R' and 'S' merge to 'R'.
10633               // 'M' and 'A|R|S' is an error.
10634               if (out_attr[i].int_value() == 0
10635                   || (out_attr[i].int_value() == 'S'
10636                       && (in_attr[i].int_value() == 'A'
10637                           || in_attr[i].int_value() == 'R')))
10638                 out_attr[i].set_int_value(in_attr[i].int_value());
10639               else if (in_attr[i].int_value() == 0
10640                        || (in_attr[i].int_value() == 'S'
10641                            && (out_attr[i].int_value() == 'A'
10642                                || out_attr[i].int_value() == 'R')))
10643                 ; // Do nothing.
10644               else if (parameters->options().warn_mismatch())
10645                 {
10646                   gold_error
10647                     (_("conflicting architecture profiles %c/%c"),
10648                      in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10649                      out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10650                 }
10651             }
10652           break;
10653         case elfcpp::Tag_VFP_arch:
10654             {
10655               static const struct
10656               {
10657                   int ver;
10658                   int regs;
10659               } vfp_versions[7] =
10660                 {
10661                   {0, 0},
10662                   {1, 16},
10663                   {2, 16},
10664                   {3, 32},
10665                   {3, 16},
10666                   {4, 32},
10667                   {4, 16}
10668                 };
10669
10670               // Values greater than 6 aren't defined, so just pick the
10671               // biggest.
10672               if (in_attr[i].int_value() > 6
10673                   && in_attr[i].int_value() > out_attr[i].int_value())
10674                 {
10675                   *out_attr = *in_attr;
10676                   break;
10677                 }
10678               // The output uses the superset of input features
10679               // (ISA version) and registers.
10680               int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10681                                  vfp_versions[out_attr[i].int_value()].ver);
10682               int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10683                                   vfp_versions[out_attr[i].int_value()].regs);
10684               // This assumes all possible supersets are also a valid
10685               // options.
10686               int newval;
10687               for (newval = 6; newval > 0; newval--)
10688                 {
10689                   if (regs == vfp_versions[newval].regs
10690                       && ver == vfp_versions[newval].ver)
10691                     break;
10692                 }
10693               out_attr[i].set_int_value(newval);
10694             }
10695           break;
10696         case elfcpp::Tag_PCS_config:
10697           if (out_attr[i].int_value() == 0)
10698             out_attr[i].set_int_value(in_attr[i].int_value());
10699           else if (in_attr[i].int_value() != 0
10700                    && out_attr[i].int_value() != 0
10701                    && parameters->options().warn_mismatch())
10702             {
10703               // It's sometimes ok to mix different configs, so this is only
10704               // a warning.
10705               gold_warning(_("%s: conflicting platform configuration"), name);
10706             }
10707           break;
10708         case elfcpp::Tag_ABI_PCS_R9_use:
10709           if (in_attr[i].int_value() != out_attr[i].int_value()
10710               && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10711               && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10712               && parameters->options().warn_mismatch())
10713             {
10714               gold_error(_("%s: conflicting use of R9"), name);
10715             }
10716           if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10717             out_attr[i].set_int_value(in_attr[i].int_value());
10718           break;
10719         case elfcpp::Tag_ABI_PCS_RW_data:
10720           if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10721               && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10722                   != elfcpp::AEABI_R9_SB)
10723               && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10724                   != elfcpp::AEABI_R9_unused)
10725               && parameters->options().warn_mismatch())
10726             {
10727               gold_error(_("%s: SB relative addressing conflicts with use "
10728                            "of R9"),
10729                            name);
10730             }
10731           // Use the smallest value specified.
10732           if (in_attr[i].int_value() < out_attr[i].int_value())
10733             out_attr[i].set_int_value(in_attr[i].int_value());
10734           break;
10735         case elfcpp::Tag_ABI_PCS_wchar_t:
10736           if (out_attr[i].int_value()
10737               && in_attr[i].int_value()
10738               && out_attr[i].int_value() != in_attr[i].int_value()
10739               && parameters->options().warn_mismatch()
10740               && parameters->options().wchar_size_warning())
10741             {
10742               gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10743                              "use %u-byte wchar_t; use of wchar_t values "
10744                              "across objects may fail"),
10745                            name, in_attr[i].int_value(),
10746                            out_attr[i].int_value());
10747             }
10748           else if (in_attr[i].int_value() && !out_attr[i].int_value())
10749             out_attr[i].set_int_value(in_attr[i].int_value());
10750           break;
10751         case elfcpp::Tag_ABI_enum_size:
10752           if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10753             {
10754               if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10755                   || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10756                 {
10757                   // The existing object is compatible with anything.
10758                   // Use whatever requirements the new object has.
10759                   out_attr[i].set_int_value(in_attr[i].int_value());
10760                 }
10761               else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10762                        && out_attr[i].int_value() != in_attr[i].int_value()
10763                        && parameters->options().warn_mismatch()
10764                        && parameters->options().enum_size_warning())
10765                 {
10766                   unsigned int in_value = in_attr[i].int_value();
10767                   unsigned int out_value = out_attr[i].int_value();
10768                   gold_warning(_("%s uses %s enums yet the output is to use "
10769                                  "%s enums; use of enum values across objects "
10770                                  "may fail"),
10771                                name,
10772                                this->aeabi_enum_name(in_value).c_str(),
10773                                this->aeabi_enum_name(out_value).c_str());
10774                 }
10775             }
10776           break;
10777         case elfcpp::Tag_ABI_VFP_args:
10778           // Already done.
10779           break;
10780         case elfcpp::Tag_ABI_WMMX_args:
10781           if (in_attr[i].int_value() != out_attr[i].int_value()
10782               && parameters->options().warn_mismatch())
10783             {
10784               gold_error(_("%s uses iWMMXt register arguments, output does "
10785                            "not"),
10786                          name);
10787             }
10788           break;
10789         case Object_attribute::Tag_compatibility:
10790           // Merged in target-independent code.
10791           break;
10792         case elfcpp::Tag_ABI_HardFP_use:
10793           // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10794           if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10795               || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10796             out_attr[i].set_int_value(3);
10797           else if (in_attr[i].int_value() > out_attr[i].int_value())
10798             out_attr[i].set_int_value(in_attr[i].int_value());
10799           break;
10800         case elfcpp::Tag_ABI_FP_16bit_format:
10801           if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10802             {
10803               if (in_attr[i].int_value() != out_attr[i].int_value()
10804                   && parameters->options().warn_mismatch())
10805                 gold_error(_("fp16 format mismatch between %s and output"),
10806                            name);
10807             }
10808           if (in_attr[i].int_value() != 0)
10809             out_attr[i].set_int_value(in_attr[i].int_value());
10810           break;
10811
10812         case elfcpp::Tag_DIV_use:
10813           {
10814             // A value of zero on input means that the divide
10815             // instruction may be used if available in the base
10816             // architecture as specified via Tag_CPU_arch and
10817             // Tag_CPU_arch_profile.  A value of 1 means that the user
10818             // did not want divide instructions.  A value of 2
10819             // explicitly means that divide instructions were allowed
10820             // in ARM and Thumb state.
10821             int arch = this->
10822               get_aeabi_object_attribute(elfcpp::Tag_CPU_arch)->
10823               int_value();
10824             int profile = this->
10825               get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile)->
10826               int_value();
10827             if (in_attr[i].int_value() == out_attr[i].int_value())
10828               {
10829                 // Do nothing.
10830               }
10831             else if (attributes_forbid_div(&in_attr[i])
10832                      && !attributes_accept_div(arch, profile, &out_attr[i])) 
10833               out_attr[i].set_int_value(1);
10834             else if (attributes_forbid_div(&out_attr[i])
10835                      && attributes_accept_div(arch, profile, &in_attr[i]))
10836               out_attr[i].set_int_value(in_attr[i].int_value());
10837             else if (in_attr[i].int_value() == 2)
10838               out_attr[i].set_int_value(in_attr[i].int_value());
10839           }
10840           break;
10841
10842         case elfcpp::Tag_MPextension_use_legacy:
10843           // We don't output objects with Tag_MPextension_use_legacy - we
10844           // move the value to Tag_MPextension_use.
10845           if (in_attr[i].int_value() != 0
10846               && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10847             {
10848               if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10849                   != in_attr[i].int_value())
10850                 {
10851                   gold_error(_("%s has has both the current and legacy "
10852                                "Tag_MPextension_use attributes"),
10853                              name);
10854                 }
10855             }
10856
10857           if (in_attr[i].int_value()
10858               > out_attr[elfcpp::Tag_MPextension_use].int_value())
10859             out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10860
10861           break;
10862
10863         case elfcpp::Tag_nodefaults:
10864           // This tag is set if it exists, but the value is unused (and is
10865           // typically zero).  We don't actually need to do anything here -
10866           // the merge happens automatically when the type flags are merged
10867           // below.
10868           break;
10869         case elfcpp::Tag_also_compatible_with:
10870           // Already done in Tag_CPU_arch.
10871           break;
10872         case elfcpp::Tag_conformance:
10873           // Keep the attribute if it matches.  Throw it away otherwise.
10874           // No attribute means no claim to conform.
10875           if (in_attr[i].string_value() != out_attr[i].string_value())
10876             out_attr[i].set_string_value("");
10877           break;
10878
10879         default:
10880           {
10881             const char* err_object = NULL;
10882
10883             // The "known_obj_attributes" table does contain some undefined
10884             // attributes.  Ensure that there are unused.
10885             if (out_attr[i].int_value() != 0
10886                 || out_attr[i].string_value() != "")
10887               err_object = "output";
10888             else if (in_attr[i].int_value() != 0
10889                      || in_attr[i].string_value() != "")
10890               err_object = name;
10891
10892             if (err_object != NULL
10893                 && parameters->options().warn_mismatch())
10894               {
10895                 // Attribute numbers >=64 (mod 128) can be safely ignored.
10896                 if ((i & 127) < 64)
10897                   gold_error(_("%s: unknown mandatory EABI object attribute "
10898                                "%d"),
10899                              err_object, i);
10900                 else
10901                   gold_warning(_("%s: unknown EABI object attribute %d"),
10902                                err_object, i);
10903               }
10904
10905             // Only pass on attributes that match in both inputs.
10906             if (!in_attr[i].matches(out_attr[i]))
10907               {
10908                 out_attr[i].set_int_value(0);
10909                 out_attr[i].set_string_value("");
10910               }
10911           }
10912         }
10913
10914       // If out_attr was copied from in_attr then it won't have a type yet.
10915       if (in_attr[i].type() && !out_attr[i].type())
10916         out_attr[i].set_type(in_attr[i].type());
10917     }
10918
10919   // Merge Tag_compatibility attributes and any common GNU ones.
10920   this->attributes_section_data_->merge(name, pasd);
10921
10922   // Check for any attributes not known on ARM.
10923   typedef Vendor_object_attributes::Other_attributes Other_attributes;
10924   const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10925   Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10926   Other_attributes* out_other_attributes =
10927     this->attributes_section_data_->other_attributes(vendor);
10928   Other_attributes::iterator out_iter = out_other_attributes->begin();
10929
10930   while (in_iter != in_other_attributes->end()
10931          || out_iter != out_other_attributes->end())
10932     {
10933       const char* err_object = NULL;
10934       int err_tag = 0;
10935
10936       // The tags for each list are in numerical order.
10937       // If the tags are equal, then merge.
10938       if (out_iter != out_other_attributes->end()
10939           && (in_iter == in_other_attributes->end()
10940               || in_iter->first > out_iter->first))
10941         {
10942           // This attribute only exists in output.  We can't merge, and we
10943           // don't know what the tag means, so delete it.
10944           err_object = "output";
10945           err_tag = out_iter->first;
10946           int saved_tag = out_iter->first;
10947           delete out_iter->second;
10948           out_other_attributes->erase(out_iter);
10949           out_iter = out_other_attributes->upper_bound(saved_tag);
10950         }
10951       else if (in_iter != in_other_attributes->end()
10952                && (out_iter != out_other_attributes->end()
10953                    || in_iter->first < out_iter->first))
10954         {
10955           // This attribute only exists in input. We can't merge, and we
10956           // don't know what the tag means, so ignore it.
10957           err_object = name;
10958           err_tag = in_iter->first;
10959           ++in_iter;
10960         }
10961       else // The tags are equal.
10962         {
10963           // As present, all attributes in the list are unknown, and
10964           // therefore can't be merged meaningfully.
10965           err_object = "output";
10966           err_tag = out_iter->first;
10967
10968           //  Only pass on attributes that match in both inputs.
10969           if (!in_iter->second->matches(*(out_iter->second)))
10970             {
10971               // No match.  Delete the attribute.
10972               int saved_tag = out_iter->first;
10973               delete out_iter->second;
10974               out_other_attributes->erase(out_iter);
10975               out_iter = out_other_attributes->upper_bound(saved_tag);
10976             }
10977           else
10978             {
10979               // Matched.  Keep the attribute and move to the next.
10980               ++out_iter;
10981               ++in_iter;
10982             }
10983         }
10984
10985       if (err_object && parameters->options().warn_mismatch())
10986         {
10987           // Attribute numbers >=64 (mod 128) can be safely ignored.  */
10988           if ((err_tag & 127) < 64)
10989             {
10990               gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10991                          err_object, err_tag);
10992             }
10993           else
10994             {
10995               gold_warning(_("%s: unknown EABI object attribute %d"),
10996                            err_object, err_tag);
10997             }
10998         }
10999     }
11000 }
11001
11002 // Stub-generation methods for Target_arm.
11003
11004 // Make a new Arm_input_section object.
11005
11006 template<bool big_endian>
11007 Arm_input_section<big_endian>*
11008 Target_arm<big_endian>::new_arm_input_section(
11009     Relobj* relobj,
11010     unsigned int shndx)
11011 {
11012   Section_id sid(relobj, shndx);
11013
11014   Arm_input_section<big_endian>* arm_input_section =
11015     new Arm_input_section<big_endian>(relobj, shndx);
11016   arm_input_section->init();
11017
11018   // Register new Arm_input_section in map for look-up.
11019   std::pair<typename Arm_input_section_map::iterator, bool> ins =
11020     this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
11021
11022   // Make sure that it we have not created another Arm_input_section
11023   // for this input section already.
11024   gold_assert(ins.second);
11025
11026   return arm_input_section;
11027 }
11028
11029 // Find the Arm_input_section object corresponding to the SHNDX-th input
11030 // section of RELOBJ.
11031
11032 template<bool big_endian>
11033 Arm_input_section<big_endian>*
11034 Target_arm<big_endian>::find_arm_input_section(
11035     Relobj* relobj,
11036     unsigned int shndx) const
11037 {
11038   Section_id sid(relobj, shndx);
11039   typename Arm_input_section_map::const_iterator p =
11040     this->arm_input_section_map_.find(sid);
11041   return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
11042 }
11043
11044 // Make a new stub table.
11045
11046 template<bool big_endian>
11047 Stub_table<big_endian>*
11048 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
11049 {
11050   Stub_table<big_endian>* stub_table =
11051     new Stub_table<big_endian>(owner);
11052   this->stub_tables_.push_back(stub_table);
11053
11054   stub_table->set_address(owner->address() + owner->data_size());
11055   stub_table->set_file_offset(owner->offset() + owner->data_size());
11056   stub_table->finalize_data_size();
11057
11058   return stub_table;
11059 }
11060
11061 // Scan a relocation for stub generation.
11062
11063 template<bool big_endian>
11064 void
11065 Target_arm<big_endian>::scan_reloc_for_stub(
11066     const Relocate_info<32, big_endian>* relinfo,
11067     unsigned int r_type,
11068     const Sized_symbol<32>* gsym,
11069     unsigned int r_sym,
11070     const Symbol_value<32>* psymval,
11071     elfcpp::Elf_types<32>::Elf_Swxword addend,
11072     Arm_address address)
11073 {
11074   const Arm_relobj<big_endian>* arm_relobj =
11075     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11076
11077   bool target_is_thumb;
11078   Symbol_value<32> symval;
11079   if (gsym != NULL)
11080     {
11081       // This is a global symbol.  Determine if we use PLT and if the
11082       // final target is THUMB.
11083       if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
11084         {
11085           // This uses a PLT, change the symbol value.
11086           symval.set_output_value(this->plt_section()->address()
11087                                   + gsym->plt_offset());
11088           psymval = &symval;
11089           target_is_thumb = false;
11090         }
11091       else if (gsym->is_undefined())
11092         // There is no need to generate a stub symbol is undefined.
11093         return;
11094       else
11095         {
11096           target_is_thumb =
11097             ((gsym->type() == elfcpp::STT_ARM_TFUNC)
11098              || (gsym->type() == elfcpp::STT_FUNC
11099                  && !gsym->is_undefined()
11100                  && ((psymval->value(arm_relobj, 0) & 1) != 0)));
11101         }
11102     }
11103   else
11104     {
11105       // This is a local symbol.  Determine if the final target is THUMB.
11106       target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
11107     }
11108
11109   // Strip LSB if this points to a THUMB target.
11110   const Arm_reloc_property* reloc_property =
11111     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
11112   gold_assert(reloc_property != NULL);
11113   if (target_is_thumb
11114       && reloc_property->uses_thumb_bit()
11115       && ((psymval->value(arm_relobj, 0) & 1) != 0))
11116     {
11117       Arm_address stripped_value =
11118         psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
11119       symval.set_output_value(stripped_value);
11120       psymval = &symval;
11121     }
11122
11123   // Get the symbol value.
11124   Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
11125
11126   // Owing to pipelining, the PC relative branches below actually skip
11127   // two instructions when the branch offset is 0.
11128   Arm_address destination;
11129   switch (r_type)
11130     {
11131     case elfcpp::R_ARM_CALL:
11132     case elfcpp::R_ARM_JUMP24:
11133     case elfcpp::R_ARM_PLT32:
11134       // ARM branches.
11135       destination = value + addend + 8;
11136       break;
11137     case elfcpp::R_ARM_THM_CALL:
11138     case elfcpp::R_ARM_THM_XPC22:
11139     case elfcpp::R_ARM_THM_JUMP24:
11140     case elfcpp::R_ARM_THM_JUMP19:
11141       // THUMB branches.
11142       destination = value + addend + 4;
11143       break;
11144     default:
11145       gold_unreachable();
11146     }
11147
11148   Reloc_stub* stub = NULL;
11149   Stub_type stub_type =
11150     Reloc_stub::stub_type_for_reloc(r_type, address, destination,
11151                                     target_is_thumb);
11152   if (stub_type != arm_stub_none)
11153     {
11154       // Try looking up an existing stub from a stub table.
11155       Stub_table<big_endian>* stub_table =
11156         arm_relobj->stub_table(relinfo->data_shndx);
11157       gold_assert(stub_table != NULL);
11158
11159       // Locate stub by destination.
11160       Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
11161
11162       // Create a stub if there is not one already
11163       stub = stub_table->find_reloc_stub(stub_key);
11164       if (stub == NULL)
11165         {
11166           // create a new stub and add it to stub table.
11167           stub = this->stub_factory().make_reloc_stub(stub_type);
11168           stub_table->add_reloc_stub(stub, stub_key);
11169         }
11170
11171       // Record the destination address.
11172       stub->set_destination_address(destination
11173                                     | (target_is_thumb ? 1 : 0));
11174     }
11175
11176   // For Cortex-A8, we need to record a relocation at 4K page boundary.
11177   if (this->fix_cortex_a8_
11178       && (r_type == elfcpp::R_ARM_THM_JUMP24
11179           || r_type == elfcpp::R_ARM_THM_JUMP19
11180           || r_type == elfcpp::R_ARM_THM_CALL
11181           || r_type == elfcpp::R_ARM_THM_XPC22)
11182       && (address & 0xfffU) == 0xffeU)
11183     {
11184       // Found a candidate.  Note we haven't checked the destination is
11185       // within 4K here: if we do so (and don't create a record) we can't
11186       // tell that a branch should have been relocated when scanning later.
11187       this->cortex_a8_relocs_info_[address] =
11188         new Cortex_a8_reloc(stub, r_type,
11189                             destination | (target_is_thumb ? 1 : 0));
11190     }
11191 }
11192
11193 // This function scans a relocation sections for stub generation.
11194 // The template parameter Relocate must be a class type which provides
11195 // a single function, relocate(), which implements the machine
11196 // specific part of a relocation.
11197
11198 // BIG_ENDIAN is the endianness of the data.  SH_TYPE is the section type:
11199 // SHT_REL or SHT_RELA.
11200
11201 // PRELOCS points to the relocation data.  RELOC_COUNT is the number
11202 // of relocs.  OUTPUT_SECTION is the output section.
11203 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
11204 // mapped to output offsets.
11205
11206 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
11207 // VIEW_SIZE is the size.  These refer to the input section, unless
11208 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
11209 // the output section.
11210
11211 template<bool big_endian>
11212 template<int sh_type>
11213 void inline
11214 Target_arm<big_endian>::scan_reloc_section_for_stubs(
11215     const Relocate_info<32, big_endian>* relinfo,
11216     const unsigned char* prelocs,
11217     size_t reloc_count,
11218     Output_section* output_section,
11219     bool needs_special_offset_handling,
11220     const unsigned char* view,
11221     elfcpp::Elf_types<32>::Elf_Addr view_address,
11222     section_size_type)
11223 {
11224   typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
11225   const int reloc_size =
11226     Reloc_types<sh_type, 32, big_endian>::reloc_size;
11227
11228   Arm_relobj<big_endian>* arm_object =
11229     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11230   unsigned int local_count = arm_object->local_symbol_count();
11231
11232   gold::Default_comdat_behavior default_comdat_behavior;
11233   Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11234
11235   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11236     {
11237       Reltype reloc(prelocs);
11238
11239       typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11240       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11241       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11242
11243       r_type = this->get_real_reloc_type(r_type);
11244
11245       // Only a few relocation types need stubs.
11246       if ((r_type != elfcpp::R_ARM_CALL)
11247          && (r_type != elfcpp::R_ARM_JUMP24)
11248          && (r_type != elfcpp::R_ARM_PLT32)
11249          && (r_type != elfcpp::R_ARM_THM_CALL)
11250          && (r_type != elfcpp::R_ARM_THM_XPC22)
11251          && (r_type != elfcpp::R_ARM_THM_JUMP24)
11252          && (r_type != elfcpp::R_ARM_THM_JUMP19)
11253          && (r_type != elfcpp::R_ARM_V4BX))
11254         continue;
11255
11256       section_offset_type offset =
11257         convert_to_section_size_type(reloc.get_r_offset());
11258
11259       if (needs_special_offset_handling)
11260         {
11261           offset = output_section->output_offset(relinfo->object,
11262                                                  relinfo->data_shndx,
11263                                                  offset);
11264           if (offset == -1)
11265             continue;
11266         }
11267
11268       // Create a v4bx stub if --fix-v4bx-interworking is used.
11269       if (r_type == elfcpp::R_ARM_V4BX)
11270         {
11271           if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11272             {
11273               // Get the BX instruction.
11274               typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11275               const Valtype* wv =
11276                 reinterpret_cast<const Valtype*>(view + offset);
11277               elfcpp::Elf_types<32>::Elf_Swxword insn =
11278                 elfcpp::Swap<32, big_endian>::readval(wv);
11279               const uint32_t reg = (insn & 0xf);
11280
11281               if (reg < 0xf)
11282                 {
11283                   // Try looking up an existing stub from a stub table.
11284                   Stub_table<big_endian>* stub_table =
11285                     arm_object->stub_table(relinfo->data_shndx);
11286                   gold_assert(stub_table != NULL);
11287
11288                   if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11289                     {
11290                       // create a new stub and add it to stub table.
11291                       Arm_v4bx_stub* stub =
11292                         this->stub_factory().make_arm_v4bx_stub(reg);
11293                       gold_assert(stub != NULL);
11294                       stub_table->add_arm_v4bx_stub(stub);
11295                     }
11296                 }
11297             }
11298           continue;
11299         }
11300
11301       // Get the addend.
11302       Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11303       elfcpp::Elf_types<32>::Elf_Swxword addend =
11304         stub_addend_reader(r_type, view + offset, reloc);
11305
11306       const Sized_symbol<32>* sym;
11307
11308       Symbol_value<32> symval;
11309       const Symbol_value<32> *psymval;
11310       bool is_defined_in_discarded_section;
11311       unsigned int shndx;
11312       if (r_sym < local_count)
11313         {
11314           sym = NULL;
11315           psymval = arm_object->local_symbol(r_sym);
11316
11317           // If the local symbol belongs to a section we are discarding,
11318           // and that section is a debug section, try to find the
11319           // corresponding kept section and map this symbol to its
11320           // counterpart in the kept section.  The symbol must not
11321           // correspond to a section we are folding.
11322           bool is_ordinary;
11323           shndx = psymval->input_shndx(&is_ordinary);
11324           is_defined_in_discarded_section =
11325             (is_ordinary
11326              && shndx != elfcpp::SHN_UNDEF
11327              && !arm_object->is_section_included(shndx)
11328              && !relinfo->symtab->is_section_folded(arm_object, shndx));
11329
11330           // We need to compute the would-be final value of this local
11331           // symbol.
11332           if (!is_defined_in_discarded_section)
11333             {
11334               typedef Sized_relobj_file<32, big_endian> ObjType;
11335               typename ObjType::Compute_final_local_value_status status =
11336                 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11337                                                       relinfo->symtab);
11338               if (status == ObjType::CFLV_OK)
11339                 {
11340                   // Currently we cannot handle a branch to a target in
11341                   // a merged section.  If this is the case, issue an error
11342                   // and also free the merge symbol value.
11343                   if (!symval.has_output_value())
11344                     {
11345                       const std::string& section_name =
11346                         arm_object->section_name(shndx);
11347                       arm_object->error(_("cannot handle branch to local %u "
11348                                           "in a merged section %s"),
11349                                         r_sym, section_name.c_str());
11350                     }
11351                   psymval = &symval;
11352                 }
11353               else
11354                 {
11355                   // We cannot determine the final value.
11356                   continue;
11357                 }
11358             }
11359         }
11360       else
11361         {
11362           const Symbol* gsym;
11363           gsym = arm_object->global_symbol(r_sym);
11364           gold_assert(gsym != NULL);
11365           if (gsym->is_forwarder())
11366             gsym = relinfo->symtab->resolve_forwards(gsym);
11367
11368           sym = static_cast<const Sized_symbol<32>*>(gsym);
11369           if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11370             symval.set_output_symtab_index(sym->symtab_index());
11371           else
11372             symval.set_no_output_symtab_entry();
11373
11374           // We need to compute the would-be final value of this global
11375           // symbol.
11376           const Symbol_table* symtab = relinfo->symtab;
11377           const Sized_symbol<32>* sized_symbol =
11378             symtab->get_sized_symbol<32>(gsym);
11379           Symbol_table::Compute_final_value_status status;
11380           Arm_address value =
11381             symtab->compute_final_value<32>(sized_symbol, &status);
11382
11383           // Skip this if the symbol has not output section.
11384           if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11385             continue;
11386           symval.set_output_value(value);
11387
11388           if (gsym->type() == elfcpp::STT_TLS)
11389             symval.set_is_tls_symbol();
11390           else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11391             symval.set_is_ifunc_symbol();
11392           psymval = &symval;
11393
11394           is_defined_in_discarded_section =
11395             (gsym->is_defined_in_discarded_section()
11396              && gsym->is_undefined());
11397           shndx = 0;
11398         }
11399
11400       Symbol_value<32> symval2;
11401       if (is_defined_in_discarded_section)
11402         {
11403           if (comdat_behavior == CB_UNDETERMINED)
11404             {
11405               std::string name = arm_object->section_name(relinfo->data_shndx);
11406               comdat_behavior = default_comdat_behavior.get(name.c_str());
11407             }
11408           if (comdat_behavior == CB_PRETEND)
11409             {
11410               // FIXME: This case does not work for global symbols.
11411               // We have no place to store the original section index.
11412               // Fortunately this does not matter for comdat sections,
11413               // only for sections explicitly discarded by a linker
11414               // script.
11415               bool found;
11416               typename elfcpp::Elf_types<32>::Elf_Addr value =
11417                 arm_object->map_to_kept_section(shndx, &found);
11418               if (found)
11419                 symval2.set_output_value(value + psymval->input_value());
11420               else
11421                 symval2.set_output_value(0);
11422             }
11423           else
11424             {
11425               if (comdat_behavior == CB_WARNING)
11426                 gold_warning_at_location(relinfo, i, offset,
11427                                          _("relocation refers to discarded "
11428                                            "section"));
11429               symval2.set_output_value(0);
11430             }
11431           symval2.set_no_output_symtab_entry();
11432           psymval = &symval2;
11433         }
11434
11435       // If symbol is a section symbol, we don't know the actual type of
11436       // destination.  Give up.
11437       if (psymval->is_section_symbol())
11438         continue;
11439
11440       this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11441                                 addend, view_address + offset);
11442     }
11443 }
11444
11445 // Scan an input section for stub generation.
11446
11447 template<bool big_endian>
11448 void
11449 Target_arm<big_endian>::scan_section_for_stubs(
11450     const Relocate_info<32, big_endian>* relinfo,
11451     unsigned int sh_type,
11452     const unsigned char* prelocs,
11453     size_t reloc_count,
11454     Output_section* output_section,
11455     bool needs_special_offset_handling,
11456     const unsigned char* view,
11457     Arm_address view_address,
11458     section_size_type view_size)
11459 {
11460   if (sh_type == elfcpp::SHT_REL)
11461     this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11462         relinfo,
11463         prelocs,
11464         reloc_count,
11465         output_section,
11466         needs_special_offset_handling,
11467         view,
11468         view_address,
11469         view_size);
11470   else if (sh_type == elfcpp::SHT_RELA)
11471     // We do not support RELA type relocations yet.  This is provided for
11472     // completeness.
11473     this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11474         relinfo,
11475         prelocs,
11476         reloc_count,
11477         output_section,
11478         needs_special_offset_handling,
11479         view,
11480         view_address,
11481         view_size);
11482   else
11483     gold_unreachable();
11484 }
11485
11486 // Group input sections for stub generation.
11487 //
11488 // We group input sections in an output section so that the total size,
11489 // including any padding space due to alignment is smaller than GROUP_SIZE
11490 // unless the only input section in group is bigger than GROUP_SIZE already.
11491 // Then an ARM stub table is created to follow the last input section
11492 // in group.  For each group an ARM stub table is created an is placed
11493 // after the last group.  If STUB_ALWAYS_AFTER_BRANCH is false, we further
11494 // extend the group after the stub table.
11495
11496 template<bool big_endian>
11497 void
11498 Target_arm<big_endian>::group_sections(
11499     Layout* layout,
11500     section_size_type group_size,
11501     bool stubs_always_after_branch,
11502     const Task* task)
11503 {
11504   // Group input sections and insert stub table
11505   Layout::Section_list section_list;
11506   layout->get_executable_sections(&section_list);
11507   for (Layout::Section_list::const_iterator p = section_list.begin();
11508        p != section_list.end();
11509        ++p)
11510     {
11511       Arm_output_section<big_endian>* output_section =
11512         Arm_output_section<big_endian>::as_arm_output_section(*p);
11513       output_section->group_sections(group_size, stubs_always_after_branch,
11514                                      this, task);
11515     }
11516 }
11517
11518 // Relaxation hook.  This is where we do stub generation.
11519
11520 template<bool big_endian>
11521 bool
11522 Target_arm<big_endian>::do_relax(
11523     int pass,
11524     const Input_objects* input_objects,
11525     Symbol_table* symtab,
11526     Layout* layout,
11527     const Task* task)
11528 {
11529   // No need to generate stubs if this is a relocatable link.
11530   gold_assert(!parameters->options().relocatable());
11531
11532   // If this is the first pass, we need to group input sections into
11533   // stub groups.
11534   bool done_exidx_fixup = false;
11535   typedef typename Stub_table_list::iterator Stub_table_iterator;
11536   if (pass == 1)
11537     {
11538       // Determine the stub group size.  The group size is the absolute
11539       // value of the parameter --stub-group-size.  If --stub-group-size
11540       // is passed a negative value, we restrict stubs to be always after
11541       // the stubbed branches.
11542       int32_t stub_group_size_param =
11543         parameters->options().stub_group_size();
11544       bool stubs_always_after_branch = stub_group_size_param < 0;
11545       section_size_type stub_group_size = abs(stub_group_size_param);
11546
11547       if (stub_group_size == 1)
11548         {
11549           // Default value.
11550           // Thumb branch range is +-4MB has to be used as the default
11551           // maximum size (a given section can contain both ARM and Thumb
11552           // code, so the worst case has to be taken into account).  If we are
11553           // fixing cortex-a8 errata, the branch range has to be even smaller,
11554           // since wide conditional branch has a range of +-1MB only.
11555           //
11556           // This value is 48K less than that, which allows for 4096
11557           // 12-byte stubs.  If we exceed that, then we will fail to link.
11558           // The user will have to relink with an explicit group size
11559           // option.
11560             stub_group_size = 4145152;
11561         }
11562
11563       // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11564       // page as the first half of a 32-bit branch straddling two 4K pages.
11565       // This is a crude way of enforcing that.  In addition, long conditional
11566       // branches of THUMB-2 have a range of +-1M.  If we are fixing cortex-A8
11567       // erratum, limit the group size to  (1M - 12k) to avoid unreachable
11568       // cortex-A8 stubs from long conditional branches.
11569       if (this->fix_cortex_a8_)
11570         {
11571           stubs_always_after_branch = true;
11572           const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11573           stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11574         }
11575
11576       group_sections(layout, stub_group_size, stubs_always_after_branch, task);
11577
11578       // Also fix .ARM.exidx section coverage.
11579       Arm_output_section<big_endian>* exidx_output_section = NULL;
11580       for (Layout::Section_list::const_iterator p =
11581              layout->section_list().begin();
11582            p != layout->section_list().end();
11583            ++p)
11584         if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11585           {
11586             if (exidx_output_section == NULL)
11587               exidx_output_section =
11588                 Arm_output_section<big_endian>::as_arm_output_section(*p);
11589             else
11590               // We cannot handle this now.
11591               gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11592                            "non-relocatable link"),
11593                           exidx_output_section->name(),
11594                           (*p)->name());
11595           }
11596
11597       if (exidx_output_section != NULL)
11598         {
11599           this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11600                                    symtab, task);
11601           done_exidx_fixup = true;
11602         }
11603     }
11604   else
11605     {
11606       // If this is not the first pass, addresses and file offsets have
11607       // been reset at this point, set them here.
11608       for (Stub_table_iterator sp = this->stub_tables_.begin();
11609            sp != this->stub_tables_.end();
11610            ++sp)
11611         {
11612           Arm_input_section<big_endian>* owner = (*sp)->owner();
11613           off_t off = align_address(owner->original_size(),
11614                                     (*sp)->addralign());
11615           (*sp)->set_address_and_file_offset(owner->address() + off,
11616                                              owner->offset() + off);
11617         }
11618     }
11619
11620   // The Cortex-A8 stubs are sensitive to layout of code sections.  At the
11621   // beginning of each relaxation pass, just blow away all the stubs.
11622   // Alternatively, we could selectively remove only the stubs and reloc
11623   // information for code sections that have moved since the last pass.
11624   // That would require more book-keeping.
11625   if (this->fix_cortex_a8_)
11626     {
11627       // Clear all Cortex-A8 reloc information.
11628       for (typename Cortex_a8_relocs_info::const_iterator p =
11629              this->cortex_a8_relocs_info_.begin();
11630            p != this->cortex_a8_relocs_info_.end();
11631            ++p)
11632         delete p->second;
11633       this->cortex_a8_relocs_info_.clear();
11634
11635       // Remove all Cortex-A8 stubs.
11636       for (Stub_table_iterator sp = this->stub_tables_.begin();
11637            sp != this->stub_tables_.end();
11638            ++sp)
11639         (*sp)->remove_all_cortex_a8_stubs();
11640     }
11641
11642   // Scan relocs for relocation stubs
11643   for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11644        op != input_objects->relobj_end();
11645        ++op)
11646     {
11647       Arm_relobj<big_endian>* arm_relobj =
11648         Arm_relobj<big_endian>::as_arm_relobj(*op);
11649       // Lock the object so we can read from it.  This is only called
11650       // single-threaded from Layout::finalize, so it is OK to lock.
11651       Task_lock_obj<Object> tl(task, arm_relobj);
11652       arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11653     }
11654
11655   // Check all stub tables to see if any of them have their data sizes
11656   // or addresses alignments changed.  These are the only things that
11657   // matter.
11658   bool any_stub_table_changed = false;
11659   Unordered_set<const Output_section*> sections_needing_adjustment;
11660   for (Stub_table_iterator sp = this->stub_tables_.begin();
11661        (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11662        ++sp)
11663     {
11664       if ((*sp)->update_data_size_and_addralign())
11665         {
11666           // Update data size of stub table owner.
11667           Arm_input_section<big_endian>* owner = (*sp)->owner();
11668           uint64_t address = owner->address();
11669           off_t offset = owner->offset();
11670           owner->reset_address_and_file_offset();
11671           owner->set_address_and_file_offset(address, offset);
11672
11673           sections_needing_adjustment.insert(owner->output_section());
11674           any_stub_table_changed = true;
11675         }
11676     }
11677
11678   // Output_section_data::output_section() returns a const pointer but we
11679   // need to update output sections, so we record all output sections needing
11680   // update above and scan the sections here to find out what sections need
11681   // to be updated.
11682   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
11683       p != layout->section_list().end();
11684       ++p)
11685     {
11686       if (sections_needing_adjustment.find(*p)
11687           != sections_needing_adjustment.end())
11688         (*p)->set_section_offsets_need_adjustment();
11689     }
11690
11691   // Stop relaxation if no EXIDX fix-up and no stub table change.
11692   bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11693
11694   // Finalize the stubs in the last relaxation pass.
11695   if (!continue_relaxation)
11696     {
11697       for (Stub_table_iterator sp = this->stub_tables_.begin();
11698            (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11699             ++sp)
11700         (*sp)->finalize_stubs();
11701
11702       // Update output local symbol counts of objects if necessary.
11703       for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11704            op != input_objects->relobj_end();
11705            ++op)
11706         {
11707           Arm_relobj<big_endian>* arm_relobj =
11708             Arm_relobj<big_endian>::as_arm_relobj(*op);
11709
11710           // Update output local symbol counts.  We need to discard local
11711           // symbols defined in parts of input sections that are discarded by
11712           // relaxation.
11713           if (arm_relobj->output_local_symbol_count_needs_update())
11714             {
11715               // We need to lock the object's file to update it.
11716               Task_lock_obj<Object> tl(task, arm_relobj);
11717               arm_relobj->update_output_local_symbol_count();
11718             }
11719         }
11720     }
11721
11722   return continue_relaxation;
11723 }
11724
11725 // Relocate a stub.
11726
11727 template<bool big_endian>
11728 void
11729 Target_arm<big_endian>::relocate_stub(
11730     Stub* stub,
11731     const Relocate_info<32, big_endian>* relinfo,
11732     Output_section* output_section,
11733     unsigned char* view,
11734     Arm_address address,
11735     section_size_type view_size)
11736 {
11737   Relocate relocate;
11738   const Stub_template* stub_template = stub->stub_template();
11739   for (size_t i = 0; i < stub_template->reloc_count(); i++)
11740     {
11741       size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11742       const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11743
11744       unsigned int r_type = insn->r_type();
11745       section_size_type reloc_offset = stub_template->reloc_offset(i);
11746       section_size_type reloc_size = insn->size();
11747       gold_assert(reloc_offset + reloc_size <= view_size);
11748
11749       // This is the address of the stub destination.
11750       Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11751       Symbol_value<32> symval;
11752       symval.set_output_value(target);
11753
11754       // Synthesize a fake reloc just in case.  We don't have a symbol so
11755       // we use 0.
11756       unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11757       memset(reloc_buffer, 0, sizeof(reloc_buffer));
11758       elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11759       reloc_write.put_r_offset(reloc_offset);
11760       reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11761       elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11762
11763       relocate.relocate(relinfo, this, output_section,
11764                         this->fake_relnum_for_stubs, rel, r_type,
11765                         NULL, &symval, view + reloc_offset,
11766                         address + reloc_offset, reloc_size);
11767     }
11768 }
11769
11770 // Determine whether an object attribute tag takes an integer, a
11771 // string or both.
11772
11773 template<bool big_endian>
11774 int
11775 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11776 {
11777   if (tag == Object_attribute::Tag_compatibility)
11778     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11779             | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11780   else if (tag == elfcpp::Tag_nodefaults)
11781     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11782             | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11783   else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11784     return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11785   else if (tag < 32)
11786     return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11787   else
11788     return ((tag & 1) != 0
11789             ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11790             : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11791 }
11792
11793 // Reorder attributes.
11794 //
11795 // The ABI defines that Tag_conformance should be emitted first, and that
11796 // Tag_nodefaults should be second (if either is defined).  This sets those
11797 // two positions, and bumps up the position of all the remaining tags to
11798 // compensate.
11799
11800 template<bool big_endian>
11801 int
11802 Target_arm<big_endian>::do_attributes_order(int num) const
11803 {
11804   // Reorder the known object attributes in output.  We want to move
11805   // Tag_conformance to position 4 and Tag_conformance to position 5
11806   // and shift everything between 4 .. Tag_conformance - 1 to make room.
11807   if (num == 4)
11808     return elfcpp::Tag_conformance;
11809   if (num == 5)
11810     return elfcpp::Tag_nodefaults;
11811   if ((num - 2) < elfcpp::Tag_nodefaults)
11812     return num - 2;
11813   if ((num - 1) < elfcpp::Tag_conformance)
11814     return num - 1;
11815   return num;
11816 }
11817
11818 // Scan a span of THUMB code for Cortex-A8 erratum.
11819
11820 template<bool big_endian>
11821 void
11822 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11823     Arm_relobj<big_endian>* arm_relobj,
11824     unsigned int shndx,
11825     section_size_type span_start,
11826     section_size_type span_end,
11827     const unsigned char* view,
11828     Arm_address address)
11829 {
11830   // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11831   //
11832   // The opcode is BLX.W, BL.W, B.W, Bcc.W
11833   // The branch target is in the same 4KB region as the
11834   // first half of the branch.
11835   // The instruction before the branch is a 32-bit
11836   // length non-branch instruction.
11837   section_size_type i = span_start;
11838   bool last_was_32bit = false;
11839   bool last_was_branch = false;
11840   while (i < span_end)
11841     {
11842       typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11843       const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11844       uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11845       bool is_blx = false, is_b = false;
11846       bool is_bl = false, is_bcc = false;
11847
11848       bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11849       if (insn_32bit)
11850         {
11851           // Load the rest of the insn (in manual-friendly order).
11852           insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11853
11854           // Encoding T4: B<c>.W.
11855           is_b = (insn & 0xf800d000U) == 0xf0009000U;
11856           // Encoding T1: BL<c>.W.
11857           is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11858           // Encoding T2: BLX<c>.W.
11859           is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11860           // Encoding T3: B<c>.W (not permitted in IT block).
11861           is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11862                     && (insn & 0x07f00000U) != 0x03800000U);
11863         }
11864
11865       bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11866
11867       // If this instruction is a 32-bit THUMB branch that crosses a 4K
11868       // page boundary and it follows 32-bit non-branch instruction,
11869       // we need to work around.
11870       if (is_32bit_branch
11871           && ((address + i) & 0xfffU) == 0xffeU
11872           && last_was_32bit
11873           && !last_was_branch)
11874         {
11875           // Check to see if there is a relocation stub for this branch.
11876           bool force_target_arm = false;
11877           bool force_target_thumb = false;
11878           const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11879           Cortex_a8_relocs_info::const_iterator p =
11880             this->cortex_a8_relocs_info_.find(address + i);
11881
11882           if (p != this->cortex_a8_relocs_info_.end())
11883             {
11884               cortex_a8_reloc = p->second;
11885               bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11886
11887               if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11888                   && !target_is_thumb)
11889                 force_target_arm = true;
11890               else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11891                        && target_is_thumb)
11892                 force_target_thumb = true;
11893             }
11894
11895           off_t offset;
11896           Stub_type stub_type = arm_stub_none;
11897
11898           // Check if we have an offending branch instruction.
11899           uint16_t upper_insn = (insn >> 16) & 0xffffU;
11900           uint16_t lower_insn = insn & 0xffffU;
11901           typedef class Arm_relocate_functions<big_endian> RelocFuncs;
11902
11903           if (cortex_a8_reloc != NULL
11904               && cortex_a8_reloc->reloc_stub() != NULL)
11905             // We've already made a stub for this instruction, e.g.
11906             // it's a long branch or a Thumb->ARM stub.  Assume that
11907             // stub will suffice to work around the A8 erratum (see
11908             // setting of always_after_branch above).
11909             ;
11910           else if (is_bcc)
11911             {
11912               offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11913                                                               lower_insn);
11914               stub_type = arm_stub_a8_veneer_b_cond;
11915             }
11916           else if (is_b || is_bl || is_blx)
11917             {
11918               offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11919                                                          lower_insn);
11920               if (is_blx)
11921                 offset &= ~3;
11922
11923               stub_type = (is_blx
11924                            ? arm_stub_a8_veneer_blx
11925                            : (is_bl
11926                               ? arm_stub_a8_veneer_bl
11927                               : arm_stub_a8_veneer_b));
11928             }
11929
11930           if (stub_type != arm_stub_none)
11931             {
11932               Arm_address pc_for_insn = address + i + 4;
11933
11934               // The original instruction is a BL, but the target is
11935               // an ARM instruction.  If we were not making a stub,
11936               // the BL would have been converted to a BLX.  Use the
11937               // BLX stub instead in that case.
11938               if (this->may_use_v5t_interworking() && force_target_arm
11939                   && stub_type == arm_stub_a8_veneer_bl)
11940                 {
11941                   stub_type = arm_stub_a8_veneer_blx;
11942                   is_blx = true;
11943                   is_bl = false;
11944                 }
11945               // Conversely, if the original instruction was
11946               // BLX but the target is Thumb mode, use the BL stub.
11947               else if (force_target_thumb
11948                        && stub_type == arm_stub_a8_veneer_blx)
11949                 {
11950                   stub_type = arm_stub_a8_veneer_bl;
11951                   is_blx = false;
11952                   is_bl = true;
11953                 }
11954
11955               if (is_blx)
11956                 pc_for_insn &= ~3;
11957
11958               // If we found a relocation, use the proper destination,
11959               // not the offset in the (unrelocated) instruction.
11960               // Note this is always done if we switched the stub type above.
11961               if (cortex_a8_reloc != NULL)
11962                 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11963
11964               Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11965
11966               // Add a new stub if destination address in in the same page.
11967               if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11968                 {
11969                   Cortex_a8_stub* stub =
11970                     this->stub_factory_.make_cortex_a8_stub(stub_type,
11971                                                             arm_relobj, shndx,
11972                                                             address + i,
11973                                                             target, insn);
11974                   Stub_table<big_endian>* stub_table =
11975                     arm_relobj->stub_table(shndx);
11976                   gold_assert(stub_table != NULL);
11977                   stub_table->add_cortex_a8_stub(address + i, stub);
11978                 }
11979             }
11980         }
11981
11982       i += insn_32bit ? 4 : 2;
11983       last_was_32bit = insn_32bit;
11984       last_was_branch = is_32bit_branch;
11985     }
11986 }
11987
11988 // Apply the Cortex-A8 workaround.
11989
11990 template<bool big_endian>
11991 void
11992 Target_arm<big_endian>::apply_cortex_a8_workaround(
11993     const Cortex_a8_stub* stub,
11994     Arm_address stub_address,
11995     unsigned char* insn_view,
11996     Arm_address insn_address)
11997 {
11998   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11999   Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
12000   Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
12001   Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
12002   off_t branch_offset = stub_address - (insn_address + 4);
12003
12004   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
12005   switch (stub->stub_template()->type())
12006     {
12007     case arm_stub_a8_veneer_b_cond:
12008       // For a conditional branch, we re-write it to be an unconditional
12009       // branch to the stub.  We use the THUMB-2 encoding here.
12010       upper_insn = 0xf000U;
12011       lower_insn = 0xb800U;
12012       // Fall through
12013     case arm_stub_a8_veneer_b:
12014     case arm_stub_a8_veneer_bl:
12015     case arm_stub_a8_veneer_blx:
12016       if ((lower_insn & 0x5000U) == 0x4000U)
12017         // For a BLX instruction, make sure that the relocation is
12018         // rounded up to a word boundary.  This follows the semantics of
12019         // the instruction which specifies that bit 1 of the target
12020         // address will come from bit 1 of the base address.
12021         branch_offset = (branch_offset + 2) & ~3;
12022
12023       // Put BRANCH_OFFSET back into the insn.
12024       gold_assert(!Bits<25>::has_overflow32(branch_offset));
12025       upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
12026       lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
12027       break;
12028
12029     default:
12030       gold_unreachable();
12031     }
12032
12033   // Put the relocated value back in the object file:
12034   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
12035   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
12036 }
12037
12038 // Target selector for ARM.  Note this is never instantiated directly.
12039 // It's only used in Target_selector_arm_nacl, below.
12040
12041 template<bool big_endian>
12042 class Target_selector_arm : public Target_selector
12043 {
12044  public:
12045   Target_selector_arm()
12046     : Target_selector(elfcpp::EM_ARM, 32, big_endian,
12047                       (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
12048                       (big_endian ? "armelfb" : "armelf"))
12049   { }
12050
12051   Target*
12052   do_instantiate_target()
12053   { return new Target_arm<big_endian>(); }
12054 };
12055
12056 // Fix .ARM.exidx section coverage.
12057
12058 template<bool big_endian>
12059 void
12060 Target_arm<big_endian>::fix_exidx_coverage(
12061     Layout* layout,
12062     const Input_objects* input_objects,
12063     Arm_output_section<big_endian>* exidx_section,
12064     Symbol_table* symtab,
12065     const Task* task)
12066 {
12067   // We need to look at all the input sections in output in ascending
12068   // order of of output address.  We do that by building a sorted list
12069   // of output sections by addresses.  Then we looks at the output sections
12070   // in order.  The input sections in an output section are already sorted
12071   // by addresses within the output section.
12072
12073   typedef std::set<Output_section*, output_section_address_less_than>
12074       Sorted_output_section_list;
12075   Sorted_output_section_list sorted_output_sections;
12076
12077   // Find out all the output sections of input sections pointed by
12078   // EXIDX input sections.
12079   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
12080        p != input_objects->relobj_end();
12081        ++p)
12082     {
12083       Arm_relobj<big_endian>* arm_relobj =
12084         Arm_relobj<big_endian>::as_arm_relobj(*p);
12085       std::vector<unsigned int> shndx_list;
12086       arm_relobj->get_exidx_shndx_list(&shndx_list);
12087       for (size_t i = 0; i < shndx_list.size(); ++i)
12088         {
12089           const Arm_exidx_input_section* exidx_input_section =
12090             arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
12091           gold_assert(exidx_input_section != NULL);
12092           if (!exidx_input_section->has_errors())
12093             {
12094               unsigned int text_shndx = exidx_input_section->link();
12095               Output_section* os = arm_relobj->output_section(text_shndx);
12096               if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
12097                 sorted_output_sections.insert(os);
12098             }
12099         }
12100     }
12101
12102   // Go over the output sections in ascending order of output addresses.
12103   typedef typename Arm_output_section<big_endian>::Text_section_list
12104       Text_section_list;
12105   Text_section_list sorted_text_sections;
12106   for (typename Sorted_output_section_list::iterator p =
12107         sorted_output_sections.begin();
12108       p != sorted_output_sections.end();
12109       ++p)
12110     {
12111       Arm_output_section<big_endian>* arm_output_section =
12112         Arm_output_section<big_endian>::as_arm_output_section(*p);
12113       arm_output_section->append_text_sections_to_list(&sorted_text_sections);
12114     }
12115
12116   exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
12117                                     merge_exidx_entries(), task);
12118 }
12119
12120 template<bool big_endian>
12121 void
12122 Target_arm<big_endian>::do_define_standard_symbols(
12123     Symbol_table* symtab,
12124     Layout* layout)
12125 {
12126   // Handle the .ARM.exidx section.
12127   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
12128
12129   if (exidx_section != NULL)
12130     {
12131       // Create __exidx_start and __exidx_end symbols.
12132       symtab->define_in_output_data("__exidx_start",
12133                                     NULL, // version
12134                                     Symbol_table::PREDEFINED,
12135                                     exidx_section,
12136                                     0, // value
12137                                     0, // symsize
12138                                     elfcpp::STT_NOTYPE,
12139                                     elfcpp::STB_GLOBAL,
12140                                     elfcpp::STV_HIDDEN,
12141                                     0, // nonvis
12142                                     false, // offset_is_from_end
12143                                     true); // only_if_ref
12144
12145       symtab->define_in_output_data("__exidx_end",
12146                                     NULL, // version
12147                                     Symbol_table::PREDEFINED,
12148                                     exidx_section,
12149                                     0, // value
12150                                     0, // symsize
12151                                     elfcpp::STT_NOTYPE,
12152                                     elfcpp::STB_GLOBAL,
12153                                     elfcpp::STV_HIDDEN,
12154                                     0, // nonvis
12155                                     true, // offset_is_from_end
12156                                     true); // only_if_ref
12157     }
12158   else
12159     {
12160       // Define __exidx_start and __exidx_end even when .ARM.exidx
12161       // section is missing to match ld's behaviour.
12162       symtab->define_as_constant("__exidx_start", NULL,
12163                                  Symbol_table::PREDEFINED,
12164                                  0, 0, elfcpp::STT_OBJECT,
12165                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12166                                  true, false);
12167       symtab->define_as_constant("__exidx_end", NULL,
12168                                  Symbol_table::PREDEFINED,
12169                                  0, 0, elfcpp::STT_OBJECT,
12170                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12171                                  true, false);
12172     }
12173 }
12174
12175 // NaCl variant.  It uses different PLT contents.
12176
12177 template<bool big_endian>
12178 class Output_data_plt_arm_nacl;
12179
12180 template<bool big_endian>
12181 class Target_arm_nacl : public Target_arm<big_endian>
12182 {
12183  public:
12184   Target_arm_nacl()
12185     : Target_arm<big_endian>(&arm_nacl_info)
12186   { }
12187
12188  protected:
12189   virtual Output_data_plt_arm<big_endian>*
12190   do_make_data_plt(Layout* layout, Output_data_space* got_plt)
12191   { return new Output_data_plt_arm_nacl<big_endian>(layout, got_plt); }
12192
12193  private:
12194   static const Target::Target_info arm_nacl_info;
12195 };
12196
12197 template<bool big_endian>
12198 const Target::Target_info Target_arm_nacl<big_endian>::arm_nacl_info =
12199 {
12200   32,                   // size
12201   big_endian,           // is_big_endian
12202   elfcpp::EM_ARM,       // machine_code
12203   false,                // has_make_symbol
12204   false,                // has_resolve
12205   false,                // has_code_fill
12206   true,                 // is_default_stack_executable
12207   false,                // can_icf_inline_merge_sections
12208   '\0',                 // wrap_char
12209   "/lib/ld-nacl-arm.so.1", // dynamic_linker
12210   0x20000,              // default_text_segment_address
12211   0x10000,              // abi_pagesize (overridable by -z max-page-size)
12212   0x10000,              // common_pagesize (overridable by -z common-page-size)
12213   true,                 // isolate_execinstr
12214   0x10000000,           // rosegment_gap
12215   elfcpp::SHN_UNDEF,    // small_common_shndx
12216   elfcpp::SHN_UNDEF,    // large_common_shndx
12217   0,                    // small_common_section_flags
12218   0,                    // large_common_section_flags
12219   ".ARM.attributes",    // attributes_section
12220   "aeabi",              // attributes_vendor
12221   "_start"              // entry_symbol_name
12222 };
12223
12224 template<bool big_endian>
12225 class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
12226 {
12227  public:
12228   Output_data_plt_arm_nacl(Layout* layout, Output_data_space* got_plt)
12229     : Output_data_plt_arm<big_endian>(layout, 16, got_plt)
12230   { }
12231
12232  protected:
12233   // Return the offset of the first non-reserved PLT entry.
12234   virtual unsigned int
12235   do_first_plt_entry_offset() const
12236   { return sizeof(first_plt_entry); }
12237
12238   // Return the size of a PLT entry.
12239   virtual unsigned int
12240   do_get_plt_entry_size() const
12241   { return sizeof(plt_entry); }
12242
12243   virtual void
12244   do_fill_first_plt_entry(unsigned char* pov,
12245                           Arm_address got_address,
12246                           Arm_address plt_address);
12247
12248   virtual void
12249   do_fill_plt_entry(unsigned char* pov,
12250                     Arm_address got_address,
12251                     Arm_address plt_address,
12252                     unsigned int got_offset,
12253                     unsigned int plt_offset);
12254
12255  private:
12256   inline uint32_t arm_movw_immediate(uint32_t value)
12257   {
12258     return (value & 0x00000fff) | ((value & 0x0000f000) << 4);
12259   }
12260
12261   inline uint32_t arm_movt_immediate(uint32_t value)
12262   {
12263     return ((value & 0x0fff0000) >> 16) | ((value & 0xf0000000) >> 12);
12264   }
12265
12266   // Template for the first PLT entry.
12267   static const uint32_t first_plt_entry[16];
12268
12269   // Template for subsequent PLT entries.
12270   static const uint32_t plt_entry[4];
12271 };
12272
12273 // The first entry in the PLT.
12274 template<bool big_endian>
12275 const uint32_t Output_data_plt_arm_nacl<big_endian>::first_plt_entry[16] =
12276 {
12277   // First bundle:
12278   0xe300c000,                           // movw ip, #:lower16:&GOT[2]-.+8
12279   0xe340c000,                           // movt ip, #:upper16:&GOT[2]-.+8
12280   0xe08cc00f,                           // add  ip, ip, pc
12281   0xe52dc008,                           // str  ip, [sp, #-8]!
12282   // Second bundle:
12283   0xe3ccc103,                           // bic  ip, ip, #0xc0000000
12284   0xe59cc000,                           // ldr  ip, [ip]
12285   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
12286   0xe12fff1c,                           // bx   ip
12287   // Third bundle:
12288   0xe320f000,                           // nop
12289   0xe320f000,                           // nop
12290   0xe320f000,                           // nop
12291   // .Lplt_tail:
12292   0xe50dc004,                           // str  ip, [sp, #-4]
12293   // Fourth bundle:
12294   0xe3ccc103,                           // bic  ip, ip, #0xc0000000
12295   0xe59cc000,                           // ldr  ip, [ip]
12296   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
12297   0xe12fff1c,                           // bx   ip
12298 };
12299
12300 template<bool big_endian>
12301 void
12302 Output_data_plt_arm_nacl<big_endian>::do_fill_first_plt_entry(
12303     unsigned char* pov,
12304     Arm_address got_address,
12305     Arm_address plt_address)
12306 {
12307   // Write first PLT entry.  All but first two words are constants.
12308   const size_t num_first_plt_words = (sizeof(first_plt_entry)
12309                                       / sizeof(first_plt_entry[0]));
12310
12311   int32_t got_displacement = got_address + 8 - (plt_address + 16);
12312
12313   elfcpp::Swap<32, big_endian>::writeval
12314     (pov + 0, first_plt_entry[0] | arm_movw_immediate (got_displacement));
12315   elfcpp::Swap<32, big_endian>::writeval
12316     (pov + 4, first_plt_entry[1] | arm_movt_immediate (got_displacement));
12317
12318   for (size_t i = 2; i < num_first_plt_words; ++i)
12319     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
12320 }
12321
12322 // Subsequent entries in the PLT.
12323
12324 template<bool big_endian>
12325 const uint32_t Output_data_plt_arm_nacl<big_endian>::plt_entry[4] =
12326 {
12327   0xe300c000,                           // movw ip, #:lower16:&GOT[n]-.+8
12328   0xe340c000,                           // movt ip, #:upper16:&GOT[n]-.+8
12329   0xe08cc00f,                           // add  ip, ip, pc
12330   0xea000000,                           // b    .Lplt_tail
12331 };
12332
12333 template<bool big_endian>
12334 void
12335 Output_data_plt_arm_nacl<big_endian>::do_fill_plt_entry(
12336     unsigned char* pov,
12337     Arm_address got_address,
12338     Arm_address plt_address,
12339     unsigned int got_offset,
12340     unsigned int plt_offset)
12341 {
12342   // Calculate the displacement between the PLT slot and the
12343   // common tail that's part of the special initial PLT slot.
12344   int32_t tail_displacement = (plt_address + (11 * sizeof(uint32_t))
12345                                - (plt_address + plt_offset
12346                                   + sizeof(plt_entry) + sizeof(uint32_t)));
12347   gold_assert((tail_displacement & 3) == 0);
12348   tail_displacement >>= 2;
12349
12350   gold_assert ((tail_displacement & 0xff000000) == 0
12351                || (-tail_displacement & 0xff000000) == 0);
12352
12353   // Calculate the displacement between the PLT slot and the entry
12354   // in the GOT.  The offset accounts for the value produced by
12355   // adding to pc in the penultimate instruction of the PLT stub.
12356   const int32_t got_displacement = (got_address + got_offset
12357                                     - (plt_address + sizeof(plt_entry)));
12358
12359   elfcpp::Swap<32, big_endian>::writeval
12360     (pov + 0, plt_entry[0] | arm_movw_immediate (got_displacement));
12361   elfcpp::Swap<32, big_endian>::writeval
12362     (pov + 4, plt_entry[1] | arm_movt_immediate (got_displacement));
12363   elfcpp::Swap<32, big_endian>::writeval
12364     (pov + 8, plt_entry[2]);
12365   elfcpp::Swap<32, big_endian>::writeval
12366     (pov + 12, plt_entry[3] | (tail_displacement & 0x00ffffff));
12367 }
12368
12369 // Target selectors.
12370
12371 template<bool big_endian>
12372 class Target_selector_arm_nacl
12373   : public Target_selector_nacl<Target_selector_arm<big_endian>,
12374                                 Target_arm_nacl<big_endian> >
12375 {
12376  public:
12377   Target_selector_arm_nacl()
12378     : Target_selector_nacl<Target_selector_arm<big_endian>,
12379                            Target_arm_nacl<big_endian> >(
12380           "arm",
12381           big_endian ? "elf32-bigarm-nacl" : "elf32-littlearm-nacl",
12382           big_endian ? "armelfb_nacl" : "armelf_nacl")
12383   { }
12384 };
12385
12386 Target_selector_arm_nacl<false> target_selector_arm;
12387 Target_selector_arm_nacl<true> target_selector_armbe;
12388
12389 } // End anonymous namespace.