2010-10-20 Doug Kwan <dougkwan@google.com>
[external/binutils.git] / gold / arm.cc
1 // arm.cc -- arm target support for gold.
2
3 // Copyright 2009, 2010 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
55 namespace
56 {
57
58 using namespace gold;
59
60 template<bool big_endian>
61 class Output_data_plt_arm;
62
63 template<bool big_endian>
64 class Stub_table;
65
66 template<bool big_endian>
67 class Arm_input_section;
68
69 class Arm_exidx_cantunwind;
70
71 class Arm_exidx_merged_section;
72
73 class Arm_exidx_fixup;
74
75 template<bool big_endian>
76 class Arm_output_section;
77
78 class Arm_exidx_input_section;
79
80 template<bool big_endian>
81 class Arm_relobj;
82
83 template<bool big_endian>
84 class Arm_relocate_functions;
85
86 template<bool big_endian>
87 class Arm_output_data_got;
88
89 template<bool big_endian>
90 class Target_arm;
91
92 // For convenience.
93 typedef elfcpp::Elf_types<32>::Elf_Addr Arm_address;
94
95 // Maximum branch offsets for ARM, THUMB and THUMB2.
96 const int32_t ARM_MAX_FWD_BRANCH_OFFSET = ((((1 << 23) - 1) << 2) + 8);
97 const int32_t ARM_MAX_BWD_BRANCH_OFFSET = ((-((1 << 23) << 2)) + 8);
98 const int32_t THM_MAX_FWD_BRANCH_OFFSET = ((1 << 22) -2 + 4);
99 const int32_t THM_MAX_BWD_BRANCH_OFFSET = (-(1 << 22) + 4);
100 const int32_t THM2_MAX_FWD_BRANCH_OFFSET = (((1 << 24) - 2) + 4);
101 const int32_t THM2_MAX_BWD_BRANCH_OFFSET = (-(1 << 24) + 4);
102
103 // Thread Control Block size.
104 const size_t ARM_TCB_SIZE = 8;
105
106 // The arm target class.
107 //
108 // This is a very simple port of gold for ARM-EABI.  It is intended for
109 // supporting Android only for the time being.
110 // 
111 // TODOs:
112 // - Implement all static relocation types documented in arm-reloc.def.
113 // - Make PLTs more flexible for different architecture features like
114 //   Thumb-2 and BE8.
115 // There are probably a lot more.
116
117 // Ideally we would like to avoid using global variables but this is used
118 // very in many places and sometimes in loops.  If we use a function
119 // returning a static instance of Arm_reloc_property_table, it will very
120 // slow in an threaded environment since the static instance needs to be
121 // locked.  The pointer is below initialized in the
122 // Target::do_select_as_default_target() hook so that we do not spend time
123 // building the table if we are not linking ARM objects.
124 //
125 // An alternative is to to process the information in arm-reloc.def in
126 // compilation time and generate a representation of it in PODs only.  That
127 // way we can avoid initialization when the linker starts.
128
129 Arm_reloc_property_table* arm_reloc_property_table = NULL;
130
131 // Instruction template class.  This class is similar to the insn_sequence
132 // struct in bfd/elf32-arm.c.
133
134 class Insn_template
135 {
136  public:
137   // Types of instruction templates.
138   enum Type
139     {
140       THUMB16_TYPE = 1,
141       // THUMB16_SPECIAL_TYPE is used by sub-classes of Stub for instruction 
142       // templates with class-specific semantics.  Currently this is used
143       // only by the Cortex_a8_stub class for handling condition codes in
144       // conditional branches.
145       THUMB16_SPECIAL_TYPE,
146       THUMB32_TYPE,
147       ARM_TYPE,
148       DATA_TYPE
149     };
150
151   // Factory methods to create instruction templates in different formats.
152
153   static const Insn_template
154   thumb16_insn(uint32_t data)
155   { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 0); } 
156
157   // A Thumb conditional branch, in which the proper condition is inserted
158   // when we build the stub.
159   static const Insn_template
160   thumb16_bcond_insn(uint32_t data)
161   { return Insn_template(data, THUMB16_SPECIAL_TYPE, elfcpp::R_ARM_NONE, 1); } 
162
163   static const Insn_template
164   thumb32_insn(uint32_t data)
165   { return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_NONE, 0); } 
166
167   static const Insn_template
168   thumb32_b_insn(uint32_t data, int reloc_addend)
169   {
170     return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_THM_JUMP24,
171                          reloc_addend);
172   } 
173
174   static const Insn_template
175   arm_insn(uint32_t data)
176   { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_NONE, 0); }
177
178   static const Insn_template
179   arm_rel_insn(unsigned data, int reloc_addend)
180   { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_JUMP24, reloc_addend); }
181
182   static const Insn_template
183   data_word(unsigned data, unsigned int r_type, int reloc_addend)
184   { return Insn_template(data, DATA_TYPE, r_type, reloc_addend); } 
185
186   // Accessors.  This class is used for read-only objects so no modifiers
187   // are provided.
188
189   uint32_t
190   data() const
191   { return this->data_; }
192
193   // Return the instruction sequence type of this.
194   Type
195   type() const
196   { return this->type_; }
197
198   // Return the ARM relocation type of this.
199   unsigned int
200   r_type() const
201   { return this->r_type_; }
202
203   int32_t
204   reloc_addend() const
205   { return this->reloc_addend_; }
206
207   // Return size of instruction template in bytes.
208   size_t
209   size() const;
210
211   // Return byte-alignment of instruction template.
212   unsigned
213   alignment() const;
214
215  private:
216   // We make the constructor private to ensure that only the factory
217   // methods are used.
218   inline
219   Insn_template(unsigned data, Type type, unsigned int r_type, int reloc_addend)
220     : data_(data), type_(type), r_type_(r_type), reloc_addend_(reloc_addend)
221   { }
222
223   // Instruction specific data.  This is used to store information like
224   // some of the instruction bits.
225   uint32_t data_;
226   // Instruction template type.
227   Type type_;
228   // Relocation type if there is a relocation or R_ARM_NONE otherwise.
229   unsigned int r_type_;
230   // Relocation addend.
231   int32_t reloc_addend_;
232 };
233
234 // Macro for generating code to stub types. One entry per long/short
235 // branch stub
236
237 #define DEF_STUBS \
238   DEF_STUB(long_branch_any_any) \
239   DEF_STUB(long_branch_v4t_arm_thumb) \
240   DEF_STUB(long_branch_thumb_only) \
241   DEF_STUB(long_branch_v4t_thumb_thumb) \
242   DEF_STUB(long_branch_v4t_thumb_arm) \
243   DEF_STUB(short_branch_v4t_thumb_arm) \
244   DEF_STUB(long_branch_any_arm_pic) \
245   DEF_STUB(long_branch_any_thumb_pic) \
246   DEF_STUB(long_branch_v4t_thumb_thumb_pic) \
247   DEF_STUB(long_branch_v4t_arm_thumb_pic) \
248   DEF_STUB(long_branch_v4t_thumb_arm_pic) \
249   DEF_STUB(long_branch_thumb_only_pic) \
250   DEF_STUB(a8_veneer_b_cond) \
251   DEF_STUB(a8_veneer_b) \
252   DEF_STUB(a8_veneer_bl) \
253   DEF_STUB(a8_veneer_blx) \
254   DEF_STUB(v4_veneer_bx)
255
256 // Stub types.
257
258 #define DEF_STUB(x) arm_stub_##x,
259 typedef enum
260   {
261     arm_stub_none,
262     DEF_STUBS
263
264     // First reloc stub type.
265     arm_stub_reloc_first = arm_stub_long_branch_any_any,
266     // Last  reloc stub type.
267     arm_stub_reloc_last = arm_stub_long_branch_thumb_only_pic,
268
269     // First Cortex-A8 stub type.
270     arm_stub_cortex_a8_first = arm_stub_a8_veneer_b_cond,
271     // Last Cortex-A8 stub type.
272     arm_stub_cortex_a8_last = arm_stub_a8_veneer_blx,
273     
274     // Last stub type.
275     arm_stub_type_last = arm_stub_v4_veneer_bx
276   } Stub_type;
277 #undef DEF_STUB
278
279 // Stub template class.  Templates are meant to be read-only objects.
280 // A stub template for a stub type contains all read-only attributes
281 // common to all stubs of the same type.
282
283 class Stub_template
284 {
285  public:
286   Stub_template(Stub_type, const Insn_template*, size_t);
287
288   ~Stub_template()
289   { }
290
291   // Return stub type.
292   Stub_type
293   type() const
294   { return this->type_; }
295
296   // Return an array of instruction templates.
297   const Insn_template*
298   insns() const
299   { return this->insns_; }
300
301   // Return size of template in number of instructions.
302   size_t
303   insn_count() const
304   { return this->insn_count_; }
305
306   // Return size of template in bytes.
307   size_t
308   size() const
309   { return this->size_; }
310
311   // Return alignment of the stub template.
312   unsigned
313   alignment() const
314   { return this->alignment_; }
315   
316   // Return whether entry point is in thumb mode.
317   bool
318   entry_in_thumb_mode() const
319   { return this->entry_in_thumb_mode_; }
320
321   // Return number of relocations in this template.
322   size_t
323   reloc_count() const
324   { return this->relocs_.size(); }
325
326   // Return index of the I-th instruction with relocation.
327   size_t
328   reloc_insn_index(size_t i) const
329   {
330     gold_assert(i < this->relocs_.size());
331     return this->relocs_[i].first;
332   }
333
334   // Return the offset of the I-th instruction with relocation from the
335   // beginning of the stub.
336   section_size_type
337   reloc_offset(size_t i) const
338   {
339     gold_assert(i < this->relocs_.size());
340     return this->relocs_[i].second;
341   }
342
343  private:
344   // This contains information about an instruction template with a relocation
345   // and its offset from start of stub.
346   typedef std::pair<size_t, section_size_type> Reloc;
347
348   // A Stub_template may not be copied.  We want to share templates as much
349   // as possible.
350   Stub_template(const Stub_template&);
351   Stub_template& operator=(const Stub_template&);
352   
353   // Stub type.
354   Stub_type type_;
355   // Points to an array of Insn_templates.
356   const Insn_template* insns_;
357   // Number of Insn_templates in insns_[].
358   size_t insn_count_;
359   // Size of templated instructions in bytes.
360   size_t size_;
361   // Alignment of templated instructions.
362   unsigned alignment_;
363   // Flag to indicate if entry is in thumb mode.
364   bool entry_in_thumb_mode_;
365   // A table of reloc instruction indices and offsets.  We can find these by
366   // looking at the instruction templates but we pre-compute and then stash
367   // them here for speed. 
368   std::vector<Reloc> relocs_;
369 };
370
371 //
372 // A class for code stubs.  This is a base class for different type of
373 // stubs used in the ARM target.
374 //
375
376 class Stub
377 {
378  private:
379   static const section_offset_type invalid_offset =
380     static_cast<section_offset_type>(-1);
381
382  public:
383   Stub(const Stub_template* stub_template)
384     : stub_template_(stub_template), offset_(invalid_offset)
385   { }
386
387   virtual
388    ~Stub()
389   { }
390
391   // Return the stub template.
392   const Stub_template*
393   stub_template() const
394   { return this->stub_template_; }
395
396   // Return offset of code stub from beginning of its containing stub table.
397   section_offset_type
398   offset() const
399   {
400     gold_assert(this->offset_ != invalid_offset);
401     return this->offset_;
402   }
403
404   // Set offset of code stub from beginning of its containing stub table.
405   void
406   set_offset(section_offset_type offset)
407   { this->offset_ = offset; }
408   
409   // Return the relocation target address of the i-th relocation in the
410   // stub.  This must be defined in a child class.
411   Arm_address
412   reloc_target(size_t i)
413   { return this->do_reloc_target(i); }
414
415   // Write a stub at output VIEW.  BIG_ENDIAN select how a stub is written.
416   void
417   write(unsigned char* view, section_size_type view_size, bool big_endian)
418   { this->do_write(view, view_size, big_endian); }
419
420   // Return the instruction for THUMB16_SPECIAL_TYPE instruction template
421   // for the i-th instruction.
422   uint16_t
423   thumb16_special(size_t i)
424   { return this->do_thumb16_special(i); }
425
426  protected:
427   // This must be defined in the child class.
428   virtual Arm_address
429   do_reloc_target(size_t) = 0;
430
431   // This may be overridden in the child class.
432   virtual void
433   do_write(unsigned char* view, section_size_type view_size, bool big_endian)
434   {
435     if (big_endian)
436       this->do_fixed_endian_write<true>(view, view_size);
437     else
438       this->do_fixed_endian_write<false>(view, view_size);
439   }
440   
441   // This must be overridden if a child class uses the THUMB16_SPECIAL_TYPE
442   // instruction template.
443   virtual uint16_t
444   do_thumb16_special(size_t)
445   { gold_unreachable(); }
446
447  private:
448   // A template to implement do_write.
449   template<bool big_endian>
450   void inline
451   do_fixed_endian_write(unsigned char*, section_size_type);
452
453   // Its template.
454   const Stub_template* stub_template_;
455   // Offset within the section of containing this stub.
456   section_offset_type offset_;
457 };
458
459 // Reloc stub class.  These are stubs we use to fix up relocation because
460 // of limited branch ranges.
461
462 class Reloc_stub : public Stub
463 {
464  public:
465   static const unsigned int invalid_index = static_cast<unsigned int>(-1);
466   // We assume we never jump to this address.
467   static const Arm_address invalid_address = static_cast<Arm_address>(-1);
468
469   // Return destination address.
470   Arm_address
471   destination_address() const
472   {
473     gold_assert(this->destination_address_ != this->invalid_address);
474     return this->destination_address_;
475   }
476
477   // Set destination address.
478   void
479   set_destination_address(Arm_address address)
480   {
481     gold_assert(address != this->invalid_address);
482     this->destination_address_ = address;
483   }
484
485   // Reset destination address.
486   void
487   reset_destination_address()
488   { this->destination_address_ = this->invalid_address; }
489
490   // Determine stub type for a branch of a relocation of R_TYPE going
491   // from BRANCH_ADDRESS to BRANCH_TARGET.  If TARGET_IS_THUMB is set,
492   // the branch target is a thumb instruction.  TARGET is used for look
493   // up ARM-specific linker settings.
494   static Stub_type
495   stub_type_for_reloc(unsigned int r_type, Arm_address branch_address,
496                       Arm_address branch_target, bool target_is_thumb);
497
498   // Reloc_stub key.  A key is logically a triplet of a stub type, a symbol
499   // and an addend.  Since we treat global and local symbol differently, we
500   // use a Symbol object for a global symbol and a object-index pair for
501   // a local symbol.
502   class Key
503   {
504    public:
505     // If SYMBOL is not null, this is a global symbol, we ignore RELOBJ and
506     // R_SYM.  Otherwise, this is a local symbol and RELOBJ must non-NULL
507     // and R_SYM must not be invalid_index.
508     Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj,
509         unsigned int r_sym, int32_t addend)
510       : stub_type_(stub_type), addend_(addend)
511     {
512       if (symbol != NULL)
513         {
514           this->r_sym_ = Reloc_stub::invalid_index;
515           this->u_.symbol = symbol;
516         }
517       else
518         {
519           gold_assert(relobj != NULL && r_sym != invalid_index);
520           this->r_sym_ = r_sym;
521           this->u_.relobj = relobj;
522         }
523     }
524
525     ~Key()
526     { }
527
528     // Accessors: Keys are meant to be read-only object so no modifiers are
529     // provided.
530
531     // Return stub type.
532     Stub_type
533     stub_type() const
534     { return this->stub_type_; }
535
536     // Return the local symbol index or invalid_index.
537     unsigned int
538     r_sym() const
539     { return this->r_sym_; }
540
541     // Return the symbol if there is one.
542     const Symbol*
543     symbol() const
544     { return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; }
545
546     // Return the relobj if there is one.
547     const Relobj*
548     relobj() const
549     { return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; }
550
551     // Whether this equals to another key k.
552     bool
553     eq(const Key& k) const 
554     {
555       return ((this->stub_type_ == k.stub_type_)
556               && (this->r_sym_ == k.r_sym_)
557               && ((this->r_sym_ != Reloc_stub::invalid_index)
558                   ? (this->u_.relobj == k.u_.relobj)
559                   : (this->u_.symbol == k.u_.symbol))
560               && (this->addend_ == k.addend_));
561     }
562
563     // Return a hash value.
564     size_t
565     hash_value() const
566     {
567       return (this->stub_type_
568               ^ this->r_sym_
569               ^ gold::string_hash<char>(
570                     (this->r_sym_ != Reloc_stub::invalid_index)
571                     ? this->u_.relobj->name().c_str()
572                     : this->u_.symbol->name())
573               ^ this->addend_);
574     }
575
576     // Functors for STL associative containers.
577     struct hash
578     {
579       size_t
580       operator()(const Key& k) const
581       { return k.hash_value(); }
582     };
583
584     struct equal_to
585     {
586       bool
587       operator()(const Key& k1, const Key& k2) const
588       { return k1.eq(k2); }
589     };
590
591     // Name of key.  This is mainly for debugging.
592     std::string
593     name() const;
594
595    private:
596     // Stub type.
597     Stub_type stub_type_;
598     // If this is a local symbol, this is the index in the defining object.
599     // Otherwise, it is invalid_index for a global symbol.
600     unsigned int r_sym_;
601     // If r_sym_ is invalid index.  This points to a global symbol.
602     // Otherwise, this points a relobj.  We used the unsized and target
603     // independent Symbol and Relobj classes instead of Sized_symbol<32> and  
604     // Arm_relobj.  This is done to avoid making the stub class a template
605     // as most of the stub machinery is endianness-neutral.  However, it
606     // may require a bit of casting done by users of this class.
607     union
608     {
609       const Symbol* symbol;
610       const Relobj* relobj;
611     } u_;
612     // Addend associated with a reloc.
613     int32_t addend_;
614   };
615
616  protected:
617   // Reloc_stubs are created via a stub factory.  So these are protected.
618   Reloc_stub(const Stub_template* stub_template)
619     : Stub(stub_template), destination_address_(invalid_address)
620   { }
621
622   ~Reloc_stub()
623   { }
624
625   friend class Stub_factory;
626
627   // Return the relocation target address of the i-th relocation in the
628   // stub.
629   Arm_address
630   do_reloc_target(size_t i)
631   {
632     // All reloc stub have only one relocation.
633     gold_assert(i == 0);
634     return this->destination_address_;
635   }
636
637  private:
638   // Address of destination.
639   Arm_address destination_address_;
640 };
641
642 // Cortex-A8 stub class.  We need a Cortex-A8 stub to redirect any 32-bit
643 // THUMB branch that meets the following conditions:
644 // 
645 // 1. The branch straddles across a page boundary. i.e. lower 12-bit of
646 //    branch address is 0xffe.
647 // 2. The branch target address is in the same page as the first word of the
648 //    branch.
649 // 3. The branch follows a 32-bit instruction which is not a branch.
650 //
651 // To do the fix up, we need to store the address of the branch instruction
652 // and its target at least.  We also need to store the original branch
653 // instruction bits for the condition code in a conditional branch.  The
654 // condition code is used in a special instruction template.  We also want
655 // to identify input sections needing Cortex-A8 workaround quickly.  We store
656 // extra information about object and section index of the code section
657 // containing a branch being fixed up.  The information is used to mark
658 // the code section when we finalize the Cortex-A8 stubs.
659 //
660
661 class Cortex_a8_stub : public Stub
662 {
663  public:
664   ~Cortex_a8_stub()
665   { }
666
667   // Return the object of the code section containing the branch being fixed
668   // up.
669   Relobj*
670   relobj() const
671   { return this->relobj_; }
672
673   // Return the section index of the code section containing the branch being
674   // fixed up.
675   unsigned int
676   shndx() const
677   { return this->shndx_; }
678
679   // Return the source address of stub.  This is the address of the original
680   // branch instruction.  LSB is 1 always set to indicate that it is a THUMB
681   // instruction.
682   Arm_address
683   source_address() const
684   { return this->source_address_; }
685
686   // Return the destination address of the stub.  This is the branch taken
687   // address of the original branch instruction.  LSB is 1 if it is a THUMB
688   // instruction address.
689   Arm_address
690   destination_address() const
691   { return this->destination_address_; }
692
693   // Return the instruction being fixed up.
694   uint32_t
695   original_insn() const
696   { return this->original_insn_; }
697
698  protected:
699   // Cortex_a8_stubs are created via a stub factory.  So these are protected.
700   Cortex_a8_stub(const Stub_template* stub_template, Relobj* relobj,
701                  unsigned int shndx, Arm_address source_address,
702                  Arm_address destination_address, uint32_t original_insn)
703     : Stub(stub_template), relobj_(relobj), shndx_(shndx),
704       source_address_(source_address | 1U),
705       destination_address_(destination_address),
706       original_insn_(original_insn)
707   { }
708
709   friend class Stub_factory;
710
711   // Return the relocation target address of the i-th relocation in the
712   // stub.
713   Arm_address
714   do_reloc_target(size_t i)
715   {
716     if (this->stub_template()->type() == arm_stub_a8_veneer_b_cond)
717       {
718         // The conditional branch veneer has two relocations.
719         gold_assert(i < 2);
720         return i == 0 ? this->source_address_ + 4 : this->destination_address_;
721       }
722     else
723       {
724         // All other Cortex-A8 stubs have only one relocation.
725         gold_assert(i == 0);
726         return this->destination_address_;
727       }
728   }
729
730   // Return an instruction for the THUMB16_SPECIAL_TYPE instruction template.
731   uint16_t
732   do_thumb16_special(size_t);
733
734  private:
735   // Object of the code section containing the branch being fixed up.
736   Relobj* relobj_;
737   // Section index of the code section containing the branch begin fixed up.
738   unsigned int shndx_;
739   // Source address of original branch.
740   Arm_address source_address_;
741   // Destination address of the original branch.
742   Arm_address destination_address_;
743   // Original branch instruction.  This is needed for copying the condition
744   // code from a condition branch to its stub.
745   uint32_t original_insn_;
746 };
747
748 // ARMv4 BX Rx branch relocation stub class.
749 class Arm_v4bx_stub : public Stub
750 {
751  public:
752   ~Arm_v4bx_stub()
753   { }
754
755   // Return the associated register.
756   uint32_t
757   reg() const
758   { return this->reg_; }
759
760  protected:
761   // Arm V4BX stubs are created via a stub factory.  So these are protected.
762   Arm_v4bx_stub(const Stub_template* stub_template, const uint32_t reg)
763     : Stub(stub_template), reg_(reg)
764   { }
765
766   friend class Stub_factory;
767
768   // Return the relocation target address of the i-th relocation in the
769   // stub.
770   Arm_address
771   do_reloc_target(size_t)
772   { gold_unreachable(); }
773
774   // This may be overridden in the child class.
775   virtual void
776   do_write(unsigned char* view, section_size_type view_size, bool big_endian)
777   {
778     if (big_endian)
779       this->do_fixed_endian_v4bx_write<true>(view, view_size);
780     else
781       this->do_fixed_endian_v4bx_write<false>(view, view_size);
782   }
783
784  private:
785   // A template to implement do_write.
786   template<bool big_endian>
787   void inline
788   do_fixed_endian_v4bx_write(unsigned char* view, section_size_type)
789   {
790     const Insn_template* insns = this->stub_template()->insns();
791     elfcpp::Swap<32, big_endian>::writeval(view,
792                                            (insns[0].data()
793                                            + (this->reg_ << 16)));
794     view += insns[0].size();
795     elfcpp::Swap<32, big_endian>::writeval(view,
796                                            (insns[1].data() + this->reg_));
797     view += insns[1].size();
798     elfcpp::Swap<32, big_endian>::writeval(view,
799                                            (insns[2].data() + this->reg_));
800   }
801
802   // A register index (r0-r14), which is associated with the stub.
803   uint32_t reg_;
804 };
805
806 // Stub factory class.
807
808 class Stub_factory
809 {
810  public:
811   // Return the unique instance of this class.
812   static const Stub_factory&
813   get_instance()
814   {
815     static Stub_factory singleton;
816     return singleton;
817   }
818
819   // Make a relocation stub.
820   Reloc_stub*
821   make_reloc_stub(Stub_type stub_type) const
822   {
823     gold_assert(stub_type >= arm_stub_reloc_first
824                 && stub_type <= arm_stub_reloc_last);
825     return new Reloc_stub(this->stub_templates_[stub_type]);
826   }
827
828   // Make a Cortex-A8 stub.
829   Cortex_a8_stub*
830   make_cortex_a8_stub(Stub_type stub_type, Relobj* relobj, unsigned int shndx,
831                       Arm_address source, Arm_address destination,
832                       uint32_t original_insn) const
833   {
834     gold_assert(stub_type >= arm_stub_cortex_a8_first
835                 && stub_type <= arm_stub_cortex_a8_last);
836     return new Cortex_a8_stub(this->stub_templates_[stub_type], relobj, shndx,
837                               source, destination, original_insn);
838   }
839
840   // Make an ARM V4BX relocation stub.
841   // This method creates a stub from the arm_stub_v4_veneer_bx template only.
842   Arm_v4bx_stub*
843   make_arm_v4bx_stub(uint32_t reg) const
844   {
845     gold_assert(reg < 0xf);
846     return new Arm_v4bx_stub(this->stub_templates_[arm_stub_v4_veneer_bx],
847                              reg);
848   }
849
850  private:
851   // Constructor and destructor are protected since we only return a single
852   // instance created in Stub_factory::get_instance().
853   
854   Stub_factory();
855
856   // A Stub_factory may not be copied since it is a singleton.
857   Stub_factory(const Stub_factory&);
858   Stub_factory& operator=(Stub_factory&);
859   
860   // Stub templates.  These are initialized in the constructor.
861   const Stub_template* stub_templates_[arm_stub_type_last+1];
862 };
863
864 // A class to hold stubs for the ARM target.
865
866 template<bool big_endian>
867 class Stub_table : public Output_data
868 {
869  public:
870   Stub_table(Arm_input_section<big_endian>* owner)
871     : Output_data(), owner_(owner), reloc_stubs_(), reloc_stubs_size_(0),
872       reloc_stubs_addralign_(1), cortex_a8_stubs_(), arm_v4bx_stubs_(0xf),
873       prev_data_size_(0), prev_addralign_(1)
874   { }
875
876   ~Stub_table()
877   { }
878
879   // Owner of this stub table.
880   Arm_input_section<big_endian>*
881   owner() const
882   { return this->owner_; }
883
884   // Whether this stub table is empty.
885   bool
886   empty() const
887   {
888     return (this->reloc_stubs_.empty()
889             && this->cortex_a8_stubs_.empty()
890             && this->arm_v4bx_stubs_.empty());
891   }
892
893   // Return the current data size.
894   off_t
895   current_data_size() const
896   { return this->current_data_size_for_child(); }
897
898   // Add a STUB with using KEY.  Caller is reponsible for avoid adding
899   // if already a STUB with the same key has been added. 
900   void
901   add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key)
902   {
903     const Stub_template* stub_template = stub->stub_template();
904     gold_assert(stub_template->type() == key.stub_type());
905     this->reloc_stubs_[key] = stub;
906
907     // Assign stub offset early.  We can do this because we never remove
908     // reloc stubs and they are in the beginning of the stub table.
909     uint64_t align = stub_template->alignment();
910     this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_, align);
911     stub->set_offset(this->reloc_stubs_size_);
912     this->reloc_stubs_size_ += stub_template->size();
913     this->reloc_stubs_addralign_ =
914       std::max(this->reloc_stubs_addralign_, align);
915   }
916
917   // Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS.
918   // Caller is reponsible for avoid adding if already a STUB with the same
919   // address has been added. 
920   void
921   add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub)
922   {
923     std::pair<Arm_address, Cortex_a8_stub*> value(address, stub);
924     this->cortex_a8_stubs_.insert(value);
925   }
926
927   // Add an ARM V4BX relocation stub. A register index will be retrieved
928   // from the stub.
929   void
930   add_arm_v4bx_stub(Arm_v4bx_stub* stub)
931   {
932     gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL);
933     this->arm_v4bx_stubs_[stub->reg()] = stub;
934   }
935
936   // Remove all Cortex-A8 stubs.
937   void
938   remove_all_cortex_a8_stubs();
939
940   // Look up a relocation stub using KEY.  Return NULL if there is none.
941   Reloc_stub*
942   find_reloc_stub(const Reloc_stub::Key& key) const
943   {
944     typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
945     return (p != this->reloc_stubs_.end()) ? p->second : NULL;
946   }
947
948   // Look up an arm v4bx relocation stub using the register index.
949   // Return NULL if there is none.
950   Arm_v4bx_stub*
951   find_arm_v4bx_stub(const uint32_t reg) const
952   {
953     gold_assert(reg < 0xf);
954     return this->arm_v4bx_stubs_[reg];
955   }
956
957   // Relocate stubs in this stub table.
958   void
959   relocate_stubs(const Relocate_info<32, big_endian>*,
960                  Target_arm<big_endian>*, Output_section*,
961                  unsigned char*, Arm_address, section_size_type);
962
963   // Update data size and alignment at the end of a relaxation pass.  Return
964   // true if either data size or alignment is different from that of the
965   // previous relaxation pass.
966   bool
967   update_data_size_and_addralign();
968
969   // Finalize stubs.  Set the offsets of all stubs and mark input sections
970   // needing the Cortex-A8 workaround.
971   void
972   finalize_stubs();
973   
974   // Apply Cortex-A8 workaround to an address range.
975   void
976   apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*,
977                                               unsigned char*, Arm_address,
978                                               section_size_type);
979
980  protected:
981   // Write out section contents.
982   void
983   do_write(Output_file*);
984  
985   // Return the required alignment.
986   uint64_t
987   do_addralign() const
988   { return this->prev_addralign_; }
989
990   // Reset address and file offset.
991   void
992   do_reset_address_and_file_offset()
993   { this->set_current_data_size_for_child(this->prev_data_size_); }
994
995   // Set final data size.
996   void
997   set_final_data_size()
998   { this->set_data_size(this->current_data_size()); }
999   
1000  private:
1001   // Relocate one stub.
1002   void
1003   relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
1004                 Target_arm<big_endian>*, Output_section*,
1005                 unsigned char*, Arm_address, section_size_type);
1006
1007   // Unordered map of relocation stubs.
1008   typedef
1009     Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
1010                   Reloc_stub::Key::equal_to>
1011     Reloc_stub_map;
1012
1013   // List of Cortex-A8 stubs ordered by addresses of branches being
1014   // fixed up in output.
1015   typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list;
1016   // List of Arm V4BX relocation stubs ordered by associated registers.
1017   typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list;
1018
1019   // Owner of this stub table.
1020   Arm_input_section<big_endian>* owner_;
1021   // The relocation stubs.
1022   Reloc_stub_map reloc_stubs_;
1023   // Size of reloc stubs.
1024   off_t reloc_stubs_size_;
1025   // Maximum address alignment of reloc stubs.
1026   uint64_t reloc_stubs_addralign_;
1027   // The cortex_a8_stubs.
1028   Cortex_a8_stub_list cortex_a8_stubs_;
1029   // The Arm V4BX relocation stubs.
1030   Arm_v4bx_stub_list arm_v4bx_stubs_;
1031   // data size of this in the previous pass.
1032   off_t prev_data_size_;
1033   // address alignment of this in the previous pass.
1034   uint64_t prev_addralign_;
1035 };
1036
1037 // Arm_exidx_cantunwind class.  This represents an EXIDX_CANTUNWIND entry
1038 // we add to the end of an EXIDX input section that goes into the output.
1039
1040 class Arm_exidx_cantunwind : public Output_section_data
1041 {
1042  public:
1043   Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
1044     : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
1045   { }
1046
1047   // Return the object containing the section pointed by this.
1048   Relobj*
1049   relobj() const
1050   { return this->relobj_; }
1051
1052   // Return the section index of the section pointed by this.
1053   unsigned int
1054   shndx() const
1055   { return this->shndx_; }
1056
1057  protected:
1058   void
1059   do_write(Output_file* of)
1060   {
1061     if (parameters->target().is_big_endian())
1062       this->do_fixed_endian_write<true>(of);
1063     else
1064       this->do_fixed_endian_write<false>(of);
1065   }
1066
1067   // Write to a map file.
1068   void
1069   do_print_to_mapfile(Mapfile* mapfile) const
1070   { mapfile->print_output_data(this, _("** ARM cantunwind")); }
1071
1072  private:
1073   // Implement do_write for a given endianness.
1074   template<bool big_endian>
1075   void inline
1076   do_fixed_endian_write(Output_file*);
1077   
1078   // The object containing the section pointed by this.
1079   Relobj* relobj_;
1080   // The section index of the section pointed by this.
1081   unsigned int shndx_;
1082 };
1083
1084 // During EXIDX coverage fix-up, we compact an EXIDX section.  The
1085 // Offset map is used to map input section offset within the EXIDX section
1086 // to the output offset from the start of this EXIDX section. 
1087
1088 typedef std::map<section_offset_type, section_offset_type>
1089         Arm_exidx_section_offset_map;
1090
1091 // Arm_exidx_merged_section class.  This represents an EXIDX input section
1092 // with some of its entries merged.
1093
1094 class Arm_exidx_merged_section : public Output_relaxed_input_section
1095 {
1096  public:
1097   // Constructor for Arm_exidx_merged_section.
1098   // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
1099   // SECTION_OFFSET_MAP points to a section offset map describing how
1100   // parts of the input section are mapped to output.  DELETED_BYTES is
1101   // the number of bytes deleted from the EXIDX input section.
1102   Arm_exidx_merged_section(
1103       const Arm_exidx_input_section& exidx_input_section,
1104       const Arm_exidx_section_offset_map& section_offset_map,
1105       uint32_t deleted_bytes);
1106
1107   // Return the original EXIDX input section.
1108   const Arm_exidx_input_section&
1109   exidx_input_section() const
1110   { return this->exidx_input_section_; }
1111
1112   // Return the section offset map.
1113   const Arm_exidx_section_offset_map&
1114   section_offset_map() const
1115   { return this->section_offset_map_; }
1116
1117  protected:
1118   // Write merged section into file OF.
1119   void
1120   do_write(Output_file* of);
1121
1122   bool
1123   do_output_offset(const Relobj*, unsigned int, section_offset_type,
1124                   section_offset_type*) const;
1125
1126  private:
1127   // Original EXIDX input section.
1128   const Arm_exidx_input_section& exidx_input_section_;
1129   // Section offset map.
1130   const Arm_exidx_section_offset_map& section_offset_map_;
1131 };
1132
1133 // A class to wrap an ordinary input section containing executable code.
1134
1135 template<bool big_endian>
1136 class Arm_input_section : public Output_relaxed_input_section
1137 {
1138  public:
1139   Arm_input_section(Relobj* relobj, unsigned int shndx)
1140     : Output_relaxed_input_section(relobj, shndx, 1),
1141       original_addralign_(1), original_size_(0), stub_table_(NULL)
1142   { }
1143
1144   ~Arm_input_section()
1145   { }
1146
1147   // Initialize.
1148   void
1149   init();
1150   
1151   // Whether this is a stub table owner.
1152   bool
1153   is_stub_table_owner() const
1154   { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
1155
1156   // Return the stub table.
1157   Stub_table<big_endian>*
1158   stub_table() const
1159   { return this->stub_table_; }
1160
1161   // Set the stub_table.
1162   void
1163   set_stub_table(Stub_table<big_endian>* stub_table)
1164   { this->stub_table_ = stub_table; }
1165
1166   // Downcast a base pointer to an Arm_input_section pointer.  This is
1167   // not type-safe but we only use Arm_input_section not the base class.
1168   static Arm_input_section<big_endian>*
1169   as_arm_input_section(Output_relaxed_input_section* poris)
1170   { return static_cast<Arm_input_section<big_endian>*>(poris); }
1171
1172   // Return the original size of the section.
1173   uint32_t
1174   original_size() const
1175   { return this->original_size_; }
1176
1177  protected:
1178   // Write data to output file.
1179   void
1180   do_write(Output_file*);
1181
1182   // Return required alignment of this.
1183   uint64_t
1184   do_addralign() const
1185   {
1186     if (this->is_stub_table_owner())
1187       return std::max(this->stub_table_->addralign(),
1188                       static_cast<uint64_t>(this->original_addralign_));
1189     else
1190       return this->original_addralign_;
1191   }
1192
1193   // Finalize data size.
1194   void
1195   set_final_data_size();
1196
1197   // Reset address and file offset.
1198   void
1199   do_reset_address_and_file_offset();
1200
1201   // Output offset.
1202   bool
1203   do_output_offset(const Relobj* object, unsigned int shndx,
1204                    section_offset_type offset,
1205                    section_offset_type* poutput) const
1206   {
1207     if ((object == this->relobj())
1208         && (shndx == this->shndx())
1209         && (offset >= 0)
1210         && (offset <=
1211             convert_types<section_offset_type, uint32_t>(this->original_size_)))
1212       {
1213         *poutput = offset;
1214         return true;
1215       }
1216     else
1217       return false;
1218   }
1219
1220  private:
1221   // Copying is not allowed.
1222   Arm_input_section(const Arm_input_section&);
1223   Arm_input_section& operator=(const Arm_input_section&);
1224
1225   // Address alignment of the original input section.
1226   uint32_t original_addralign_;
1227   // Section size of the original input section.
1228   uint32_t original_size_;
1229   // Stub table.
1230   Stub_table<big_endian>* stub_table_;
1231 };
1232
1233 // Arm_exidx_fixup class.  This is used to define a number of methods
1234 // and keep states for fixing up EXIDX coverage.
1235
1236 class Arm_exidx_fixup
1237 {
1238  public:
1239   Arm_exidx_fixup(Output_section* exidx_output_section,
1240                   bool merge_exidx_entries = true)
1241     : exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE),
1242       last_inlined_entry_(0), last_input_section_(NULL),
1243       section_offset_map_(NULL), first_output_text_section_(NULL),
1244       merge_exidx_entries_(merge_exidx_entries)
1245   { }
1246
1247   ~Arm_exidx_fixup()
1248   { delete this->section_offset_map_; }
1249
1250   // Process an EXIDX section for entry merging.  Return  number of bytes to
1251   // be deleted in output.  If parts of the input EXIDX section are merged
1252   // a heap allocated Arm_exidx_section_offset_map is store in the located
1253   // PSECTION_OFFSET_MAP.  The caller owns the map and is reponsible for
1254   // releasing it.
1255   template<bool big_endian>
1256   uint32_t
1257   process_exidx_section(const Arm_exidx_input_section* exidx_input_section,
1258                         Arm_exidx_section_offset_map** psection_offset_map);
1259   
1260   // Append an EXIDX_CANTUNWIND entry pointing at the end of the last
1261   // input section, if there is not one already.
1262   void
1263   add_exidx_cantunwind_as_needed();
1264
1265   // Return the output section for the text section which is linked to the
1266   // first exidx input in output.
1267   Output_section*
1268   first_output_text_section() const
1269   { return this->first_output_text_section_; }
1270
1271  private:
1272   // Copying is not allowed.
1273   Arm_exidx_fixup(const Arm_exidx_fixup&);
1274   Arm_exidx_fixup& operator=(const Arm_exidx_fixup&);
1275
1276   // Type of EXIDX unwind entry.
1277   enum Unwind_type
1278   {
1279     // No type.
1280     UT_NONE,
1281     // EXIDX_CANTUNWIND.
1282     UT_EXIDX_CANTUNWIND,
1283     // Inlined entry.
1284     UT_INLINED_ENTRY,
1285     // Normal entry.
1286     UT_NORMAL_ENTRY,
1287   };
1288
1289   // Process an EXIDX entry.  We only care about the second word of the
1290   // entry.  Return true if the entry can be deleted.
1291   bool
1292   process_exidx_entry(uint32_t second_word);
1293
1294   // Update the current section offset map during EXIDX section fix-up.
1295   // If there is no map, create one.  INPUT_OFFSET is the offset of a
1296   // reference point, DELETED_BYTES is the number of deleted by in the
1297   // section so far.  If DELETE_ENTRY is true, the reference point and
1298   // all offsets after the previous reference point are discarded.
1299   void
1300   update_offset_map(section_offset_type input_offset,
1301                     section_size_type deleted_bytes, bool delete_entry);
1302
1303   // EXIDX output section.
1304   Output_section* exidx_output_section_;
1305   // Unwind type of the last EXIDX entry processed.
1306   Unwind_type last_unwind_type_;
1307   // Last seen inlined EXIDX entry.
1308   uint32_t last_inlined_entry_;
1309   // Last processed EXIDX input section.
1310   const Arm_exidx_input_section* last_input_section_;
1311   // Section offset map created in process_exidx_section.
1312   Arm_exidx_section_offset_map* section_offset_map_;
1313   // Output section for the text section which is linked to the first exidx
1314   // input in output.
1315   Output_section* first_output_text_section_;
1316
1317   bool merge_exidx_entries_;
1318 };
1319
1320 // Arm output section class.  This is defined mainly to add a number of
1321 // stub generation methods.
1322
1323 template<bool big_endian>
1324 class Arm_output_section : public Output_section
1325 {
1326  public:
1327   typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list;
1328
1329   Arm_output_section(const char* name, elfcpp::Elf_Word type,
1330                      elfcpp::Elf_Xword flags)
1331     : Output_section(name, type, flags)
1332   {
1333     if (type == elfcpp::SHT_ARM_EXIDX)
1334       this->set_always_keeps_input_sections();
1335   }
1336
1337   ~Arm_output_section()
1338   { }
1339   
1340   // Group input sections for stub generation.
1341   void
1342   group_sections(section_size_type, bool, Target_arm<big_endian>*);
1343
1344   // Downcast a base pointer to an Arm_output_section pointer.  This is
1345   // not type-safe but we only use Arm_output_section not the base class.
1346   static Arm_output_section<big_endian>*
1347   as_arm_output_section(Output_section* os)
1348   { return static_cast<Arm_output_section<big_endian>*>(os); }
1349
1350   // Append all input text sections in this into LIST.
1351   void
1352   append_text_sections_to_list(Text_section_list* list);
1353
1354   // Fix EXIDX coverage of this EXIDX output section.  SORTED_TEXT_SECTION
1355   // is a list of text input sections sorted in ascending order of their
1356   // output addresses.
1357   void
1358   fix_exidx_coverage(Layout* layout,
1359                      const Text_section_list& sorted_text_section,
1360                      Symbol_table* symtab,
1361                      bool merge_exidx_entries);
1362
1363   // Link an EXIDX section into its corresponding text section.
1364   void
1365   set_exidx_section_link();
1366
1367  private:
1368   // For convenience.
1369   typedef Output_section::Input_section Input_section;
1370   typedef Output_section::Input_section_list Input_section_list;
1371
1372   // Create a stub group.
1373   void create_stub_group(Input_section_list::const_iterator,
1374                          Input_section_list::const_iterator,
1375                          Input_section_list::const_iterator,
1376                          Target_arm<big_endian>*,
1377                          std::vector<Output_relaxed_input_section*>*);
1378 };
1379
1380 // Arm_exidx_input_section class.  This represents an EXIDX input section.
1381
1382 class Arm_exidx_input_section
1383 {
1384  public:
1385   static const section_offset_type invalid_offset =
1386     static_cast<section_offset_type>(-1);
1387
1388   Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1389                           unsigned int link, uint32_t size, uint32_t addralign)
1390     : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1391       addralign_(addralign), has_errors_(false)
1392   { }
1393
1394   ~Arm_exidx_input_section()
1395   { }
1396         
1397   // Accessors:  This is a read-only class.
1398
1399   // Return the object containing this EXIDX input section.
1400   Relobj*
1401   relobj() const
1402   { return this->relobj_; }
1403
1404   // Return the section index of this EXIDX input section.
1405   unsigned int
1406   shndx() const
1407   { return this->shndx_; }
1408
1409   // Return the section index of linked text section in the same object.
1410   unsigned int
1411   link() const
1412   { return this->link_; }
1413
1414   // Return size of the EXIDX input section.
1415   uint32_t
1416   size() const
1417   { return this->size_; }
1418
1419   // Reutnr address alignment of EXIDX input section.
1420   uint32_t
1421   addralign() const
1422   { return this->addralign_; }
1423
1424   // Whether there are any errors in the EXIDX input section.
1425   bool
1426   has_errors() const
1427   { return this->has_errors_; }
1428
1429   // Set has-errors flag.
1430   void
1431   set_has_errors()
1432   { this->has_errors_ = true; }
1433
1434  private:
1435   // Object containing this.
1436   Relobj* relobj_;
1437   // Section index of this.
1438   unsigned int shndx_;
1439   // text section linked to this in the same object.
1440   unsigned int link_;
1441   // Size of this.  For ARM 32-bit is sufficient.
1442   uint32_t size_;
1443   // Address alignment of this.  For ARM 32-bit is sufficient.
1444   uint32_t addralign_;
1445   // Whether this has any errors.
1446   bool has_errors_;
1447 };
1448
1449 // Arm_relobj class.
1450
1451 template<bool big_endian>
1452 class Arm_relobj : public Sized_relobj<32, big_endian>
1453 {
1454  public:
1455   static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1456
1457   Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1458              const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1459     : Sized_relobj<32, big_endian>(name, input_file, offset, ehdr),
1460       stub_tables_(), local_symbol_is_thumb_function_(),
1461       attributes_section_data_(NULL), mapping_symbols_info_(),
1462       section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1463       output_local_symbol_count_needs_update_(false),
1464       merge_flags_and_attributes_(true)
1465   { }
1466
1467   ~Arm_relobj()
1468   { delete this->attributes_section_data_; }
1469  
1470   // Return the stub table of the SHNDX-th section if there is one.
1471   Stub_table<big_endian>*
1472   stub_table(unsigned int shndx) const
1473   {
1474     gold_assert(shndx < this->stub_tables_.size());
1475     return this->stub_tables_[shndx];
1476   }
1477
1478   // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1479   void
1480   set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1481   {
1482     gold_assert(shndx < this->stub_tables_.size());
1483     this->stub_tables_[shndx] = stub_table;
1484   }
1485
1486   // Whether a local symbol is a THUMB function.  R_SYM is the symbol table
1487   // index.  This is only valid after do_count_local_symbol is called.
1488   bool
1489   local_symbol_is_thumb_function(unsigned int r_sym) const
1490   {
1491     gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1492     return this->local_symbol_is_thumb_function_[r_sym];
1493   }
1494   
1495   // Scan all relocation sections for stub generation.
1496   void
1497   scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1498                           const Layout*);
1499
1500   // Convert regular input section with index SHNDX to a relaxed section.
1501   void
1502   convert_input_section_to_relaxed_section(unsigned shndx)
1503   {
1504     // The stubs have relocations and we need to process them after writing
1505     // out the stubs.  So relocation now must follow section write.
1506     this->set_section_offset(shndx, -1ULL);
1507     this->set_relocs_must_follow_section_writes();
1508   }
1509
1510   // Downcast a base pointer to an Arm_relobj pointer.  This is
1511   // not type-safe but we only use Arm_relobj not the base class.
1512   static Arm_relobj<big_endian>*
1513   as_arm_relobj(Relobj* relobj)
1514   { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1515
1516   // Processor-specific flags in ELF file header.  This is valid only after
1517   // reading symbols.
1518   elfcpp::Elf_Word
1519   processor_specific_flags() const
1520   { return this->processor_specific_flags_; }
1521
1522   // Attribute section data  This is the contents of the .ARM.attribute section
1523   // if there is one.
1524   const Attributes_section_data*
1525   attributes_section_data() const
1526   { return this->attributes_section_data_; }
1527
1528   // Mapping symbol location.
1529   typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1530
1531   // Functor for STL container.
1532   struct Mapping_symbol_position_less
1533   {
1534     bool
1535     operator()(const Mapping_symbol_position& p1,
1536                const Mapping_symbol_position& p2) const
1537     {
1538       return (p1.first < p2.first
1539               || (p1.first == p2.first && p1.second < p2.second));
1540     }
1541   };
1542   
1543   // We only care about the first character of a mapping symbol, so
1544   // we only store that instead of the whole symbol name.
1545   typedef std::map<Mapping_symbol_position, char,
1546                    Mapping_symbol_position_less> Mapping_symbols_info;
1547
1548   // Whether a section contains any Cortex-A8 workaround.
1549   bool
1550   section_has_cortex_a8_workaround(unsigned int shndx) const
1551   { 
1552     return (this->section_has_cortex_a8_workaround_ != NULL
1553             && (*this->section_has_cortex_a8_workaround_)[shndx]);
1554   }
1555   
1556   // Mark a section that has Cortex-A8 workaround.
1557   void
1558   mark_section_for_cortex_a8_workaround(unsigned int shndx)
1559   {
1560     if (this->section_has_cortex_a8_workaround_ == NULL)
1561       this->section_has_cortex_a8_workaround_ =
1562         new std::vector<bool>(this->shnum(), false);
1563     (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1564   }
1565
1566   // Return the EXIDX section of an text section with index SHNDX or NULL
1567   // if the text section has no associated EXIDX section.
1568   const Arm_exidx_input_section*
1569   exidx_input_section_by_link(unsigned int shndx) const
1570   {
1571     Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1572     return ((p != this->exidx_section_map_.end()
1573              && p->second->link() == shndx)
1574             ? p->second
1575             : NULL);
1576   }
1577
1578   // Return the EXIDX section with index SHNDX or NULL if there is none.
1579   const Arm_exidx_input_section*
1580   exidx_input_section_by_shndx(unsigned shndx) const
1581   {
1582     Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1583     return ((p != this->exidx_section_map_.end()
1584              && p->second->shndx() == shndx)
1585             ? p->second
1586             : NULL);
1587   }
1588
1589   // Whether output local symbol count needs updating.
1590   bool
1591   output_local_symbol_count_needs_update() const
1592   { return this->output_local_symbol_count_needs_update_; }
1593
1594   // Set output_local_symbol_count_needs_update flag to be true.
1595   void
1596   set_output_local_symbol_count_needs_update()
1597   { this->output_local_symbol_count_needs_update_ = true; }
1598   
1599   // Update output local symbol count at the end of relaxation.
1600   void
1601   update_output_local_symbol_count();
1602
1603   // Whether we want to merge processor-specific flags and attributes.
1604   bool
1605   merge_flags_and_attributes() const
1606   { return this->merge_flags_and_attributes_; }
1607   
1608   // Export list of EXIDX section indices.
1609   void
1610   get_exidx_shndx_list(std::vector<unsigned int>* list) const
1611   {
1612     list->clear();
1613     for (Exidx_section_map::const_iterator p = this->exidx_section_map_.begin();
1614          p != this->exidx_section_map_.end();
1615          ++p)
1616       {
1617         if (p->second->shndx() == p->first)
1618           list->push_back(p->first);
1619       }
1620     // Sort list to make result independent of implementation of map. 
1621     std::sort(list->begin(), list->end());
1622   }
1623
1624  protected:
1625   // Post constructor setup.
1626   void
1627   do_setup()
1628   {
1629     // Call parent's setup method.
1630     Sized_relobj<32, big_endian>::do_setup();
1631
1632     // Initialize look-up tables.
1633     Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1634     this->stub_tables_.swap(empty_stub_table_list);
1635   }
1636
1637   // Count the local symbols.
1638   void
1639   do_count_local_symbols(Stringpool_template<char>*,
1640                          Stringpool_template<char>*);
1641
1642   void
1643   do_relocate_sections(const Symbol_table* symtab, const Layout* layout,
1644                        const unsigned char* pshdrs, Output_file* of,
1645                        typename Sized_relobj<32, big_endian>::Views* pivews);
1646
1647   // Read the symbol information.
1648   void
1649   do_read_symbols(Read_symbols_data* sd);
1650
1651   // Process relocs for garbage collection.
1652   void
1653   do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1654
1655  private:
1656
1657   // Whether a section needs to be scanned for relocation stubs.
1658   bool
1659   section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1660                                     const Relobj::Output_sections&,
1661                                     const Symbol_table*, const unsigned char*);
1662
1663   // Whether a section is a scannable text section.
1664   bool
1665   section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1666                        const Output_section*, const Symbol_table*);
1667
1668   // Whether a section needs to be scanned for the Cortex-A8 erratum.
1669   bool
1670   section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1671                                         unsigned int, Output_section*,
1672                                         const Symbol_table*);
1673
1674   // Scan a section for the Cortex-A8 erratum.
1675   void
1676   scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1677                                      unsigned int, Output_section*,
1678                                      Target_arm<big_endian>*);
1679
1680   // Find the linked text section of an EXIDX section by looking at the
1681   // first reloction of the EXIDX section.  PSHDR points to the section
1682   // headers of a relocation section and PSYMS points to the local symbols.
1683   // PSHNDX points to a location storing the text section index if found.
1684   // Return whether we can find the linked section.
1685   bool
1686   find_linked_text_section(const unsigned char* pshdr,
1687                            const unsigned char* psyms, unsigned int* pshndx);
1688
1689   //
1690   // Make a new Arm_exidx_input_section object for EXIDX section with
1691   // index SHNDX and section header SHDR.  TEXT_SHNDX is the section
1692   // index of the linked text section.
1693   void
1694   make_exidx_input_section(unsigned int shndx,
1695                            const elfcpp::Shdr<32, big_endian>& shdr,
1696                            unsigned int text_shndx,
1697                            const elfcpp::Shdr<32, big_endian>& text_shdr);
1698
1699   // Return the output address of either a plain input section or a
1700   // relaxed input section.  SHNDX is the section index.
1701   Arm_address
1702   simple_input_section_output_address(unsigned int, Output_section*);
1703
1704   typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1705   typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1706     Exidx_section_map;
1707
1708   // List of stub tables.
1709   Stub_table_list stub_tables_;
1710   // Bit vector to tell if a local symbol is a thumb function or not.
1711   // This is only valid after do_count_local_symbol is called.
1712   std::vector<bool> local_symbol_is_thumb_function_;
1713   // processor-specific flags in ELF file header.
1714   elfcpp::Elf_Word processor_specific_flags_;
1715   // Object attributes if there is an .ARM.attributes section or NULL.
1716   Attributes_section_data* attributes_section_data_;
1717   // Mapping symbols information.
1718   Mapping_symbols_info mapping_symbols_info_;
1719   // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1720   std::vector<bool>* section_has_cortex_a8_workaround_;
1721   // Map a text section to its associated .ARM.exidx section, if there is one.
1722   Exidx_section_map exidx_section_map_;
1723   // Whether output local symbol count needs updating.
1724   bool output_local_symbol_count_needs_update_;
1725   // Whether we merge processor flags and attributes of this object to
1726   // output.
1727   bool merge_flags_and_attributes_;
1728 };
1729
1730 // Arm_dynobj class.
1731
1732 template<bool big_endian>
1733 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1734 {
1735  public:
1736   Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1737              const elfcpp::Ehdr<32, big_endian>& ehdr)
1738     : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1739       processor_specific_flags_(0), attributes_section_data_(NULL)
1740   { }
1741  
1742   ~Arm_dynobj()
1743   { delete this->attributes_section_data_; }
1744
1745   // Downcast a base pointer to an Arm_relobj pointer.  This is
1746   // not type-safe but we only use Arm_relobj not the base class.
1747   static Arm_dynobj<big_endian>*
1748   as_arm_dynobj(Dynobj* dynobj)
1749   { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1750
1751   // Processor-specific flags in ELF file header.  This is valid only after
1752   // reading symbols.
1753   elfcpp::Elf_Word
1754   processor_specific_flags() const
1755   { return this->processor_specific_flags_; }
1756
1757   // Attributes section data.
1758   const Attributes_section_data*
1759   attributes_section_data() const
1760   { return this->attributes_section_data_; }
1761
1762  protected:
1763   // Read the symbol information.
1764   void
1765   do_read_symbols(Read_symbols_data* sd);
1766
1767  private:
1768   // processor-specific flags in ELF file header.
1769   elfcpp::Elf_Word processor_specific_flags_;
1770   // Object attributes if there is an .ARM.attributes section or NULL.
1771   Attributes_section_data* attributes_section_data_;
1772 };
1773
1774 // Functor to read reloc addends during stub generation.
1775
1776 template<int sh_type, bool big_endian>
1777 struct Stub_addend_reader
1778 {
1779   // Return the addend for a relocation of a particular type.  Depending
1780   // on whether this is a REL or RELA relocation, read the addend from a
1781   // view or from a Reloc object.
1782   elfcpp::Elf_types<32>::Elf_Swxword
1783   operator()(
1784     unsigned int /* r_type */,
1785     const unsigned char* /* view */,
1786     const typename Reloc_types<sh_type,
1787                                32, big_endian>::Reloc& /* reloc */) const;
1788 };
1789
1790 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1791
1792 template<bool big_endian>
1793 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1794 {
1795   elfcpp::Elf_types<32>::Elf_Swxword
1796   operator()(
1797     unsigned int,
1798     const unsigned char*,
1799     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1800 };
1801
1802 // Specialized Stub_addend_reader for RELA type relocation sections.
1803 // We currently do not handle RELA type relocation sections but it is trivial
1804 // to implement the addend reader.  This is provided for completeness and to
1805 // make it easier to add support for RELA relocation sections in the future.
1806
1807 template<bool big_endian>
1808 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1809 {
1810   elfcpp::Elf_types<32>::Elf_Swxword
1811   operator()(
1812     unsigned int,
1813     const unsigned char*,
1814     const typename Reloc_types<elfcpp::SHT_RELA, 32,
1815                                big_endian>::Reloc& reloc) const
1816   { return reloc.get_r_addend(); }
1817 };
1818
1819 // Cortex_a8_reloc class.  We keep record of relocation that may need
1820 // the Cortex-A8 erratum workaround.
1821
1822 class Cortex_a8_reloc
1823 {
1824  public:
1825   Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1826                   Arm_address destination)
1827     : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1828   { }
1829
1830   ~Cortex_a8_reloc()
1831   { }
1832
1833   // Accessors:  This is a read-only class.
1834   
1835   // Return the relocation stub associated with this relocation if there is
1836   // one.
1837   const Reloc_stub*
1838   reloc_stub() const
1839   { return this->reloc_stub_; } 
1840   
1841   // Return the relocation type.
1842   unsigned int
1843   r_type() const
1844   { return this->r_type_; }
1845
1846   // Return the destination address of the relocation.  LSB stores the THUMB
1847   // bit.
1848   Arm_address
1849   destination() const
1850   { return this->destination_; }
1851
1852  private:
1853   // Associated relocation stub if there is one, or NULL.
1854   const Reloc_stub* reloc_stub_;
1855   // Relocation type.
1856   unsigned int r_type_;
1857   // Destination address of this relocation.  LSB is used to distinguish
1858   // ARM/THUMB mode.
1859   Arm_address destination_;
1860 };
1861
1862 // Arm_output_data_got class.  We derive this from Output_data_got to add
1863 // extra methods to handle TLS relocations in a static link.
1864
1865 template<bool big_endian>
1866 class Arm_output_data_got : public Output_data_got<32, big_endian>
1867 {
1868  public:
1869   Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1870     : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1871   { }
1872
1873   // Add a static entry for the GOT entry at OFFSET.  GSYM is a global
1874   // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1875   // applied in a static link.
1876   void
1877   add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1878   { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1879
1880   // Add a static reloc for the GOT entry at OFFSET.  RELOBJ is an object
1881   // defining a local symbol with INDEX.  R_TYPE is the code of a dynamic
1882   // relocation that needs to be applied in a static link.
1883   void
1884   add_static_reloc(unsigned int got_offset, unsigned int r_type,
1885                    Sized_relobj<32, big_endian>* relobj, unsigned int index)
1886   {
1887     this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1888                                                 index));
1889   }
1890
1891   // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
1892   // The first one is initialized to be 1, which is the module index for
1893   // the main executable and the second one 0.  A reloc of the type
1894   // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1895   // be applied by gold.  GSYM is a global symbol.
1896   void
1897   add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1898
1899   // Same as the above but for a local symbol in OBJECT with INDEX.
1900   void
1901   add_tls_gd32_with_static_reloc(unsigned int got_type,
1902                                  Sized_relobj<32, big_endian>* object,
1903                                  unsigned int index);
1904
1905  protected:
1906   // Write out the GOT table.
1907   void
1908   do_write(Output_file*);
1909
1910  private:
1911   // This class represent dynamic relocations that need to be applied by
1912   // gold because we are using TLS relocations in a static link.
1913   class Static_reloc
1914   {
1915    public:
1916     Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1917       : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1918     { this->u_.global.symbol = gsym; }
1919
1920     Static_reloc(unsigned int got_offset, unsigned int r_type,
1921           Sized_relobj<32, big_endian>* relobj, unsigned int index)
1922       : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1923     {
1924       this->u_.local.relobj = relobj;
1925       this->u_.local.index = index;
1926     }
1927
1928     // Return the GOT offset.
1929     unsigned int
1930     got_offset() const
1931     { return this->got_offset_; }
1932
1933     // Relocation type.
1934     unsigned int
1935     r_type() const
1936     { return this->r_type_; }
1937
1938     // Whether the symbol is global or not.
1939     bool
1940     symbol_is_global() const
1941     { return this->symbol_is_global_; }
1942
1943     // For a relocation against a global symbol, the global symbol.
1944     Symbol*
1945     symbol() const
1946     {
1947       gold_assert(this->symbol_is_global_);
1948       return this->u_.global.symbol;
1949     }
1950
1951     // For a relocation against a local symbol, the defining object.
1952     Sized_relobj<32, big_endian>*
1953     relobj() const
1954     {
1955       gold_assert(!this->symbol_is_global_);
1956       return this->u_.local.relobj;
1957     }
1958
1959     // For a relocation against a local symbol, the local symbol index.
1960     unsigned int
1961     index() const
1962     {
1963       gold_assert(!this->symbol_is_global_);
1964       return this->u_.local.index;
1965     }
1966
1967    private:
1968     // GOT offset of the entry to which this relocation is applied.
1969     unsigned int got_offset_;
1970     // Type of relocation.
1971     unsigned int r_type_;
1972     // Whether this relocation is against a global symbol.
1973     bool symbol_is_global_;
1974     // A global or local symbol.
1975     union
1976     {
1977       struct
1978       {
1979         // For a global symbol, the symbol itself.
1980         Symbol* symbol;
1981       } global;
1982       struct
1983       {
1984         // For a local symbol, the object defining object.
1985         Sized_relobj<32, big_endian>* relobj;
1986         // For a local symbol, the symbol index.
1987         unsigned int index;
1988       } local;
1989     } u_;
1990   };
1991
1992   // Symbol table of the output object.
1993   Symbol_table* symbol_table_;
1994   // Layout of the output object.
1995   Layout* layout_;
1996   // Static relocs to be applied to the GOT.
1997   std::vector<Static_reloc> static_relocs_;
1998 };
1999
2000 // The ARM target has many relocation types with odd-sizes or incontigious
2001 // bits.  The default handling of relocatable relocation cannot process these
2002 // relocations.  So we have to extend the default code.
2003
2004 template<bool big_endian, int sh_type, typename Classify_reloc>
2005 class Arm_scan_relocatable_relocs :
2006   public Default_scan_relocatable_relocs<sh_type, Classify_reloc>
2007 {
2008  public:
2009   // Return the strategy to use for a local symbol which is a section
2010   // symbol, given the relocation type.
2011   inline Relocatable_relocs::Reloc_strategy
2012   local_section_strategy(unsigned int r_type, Relobj*)
2013   {
2014     if (sh_type == elfcpp::SHT_RELA)
2015       return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
2016     else
2017       {
2018         if (r_type == elfcpp::R_ARM_TARGET1
2019             || r_type == elfcpp::R_ARM_TARGET2)
2020           {
2021             const Target_arm<big_endian>* arm_target =
2022               Target_arm<big_endian>::default_target();
2023             r_type = arm_target->get_real_reloc_type(r_type);
2024           }
2025
2026         switch(r_type)
2027           {
2028           // Relocations that write nothing.  These exclude R_ARM_TARGET1
2029           // and R_ARM_TARGET2.
2030           case elfcpp::R_ARM_NONE:
2031           case elfcpp::R_ARM_V4BX:
2032           case elfcpp::R_ARM_TLS_GOTDESC:
2033           case elfcpp::R_ARM_TLS_CALL:
2034           case elfcpp::R_ARM_TLS_DESCSEQ:
2035           case elfcpp::R_ARM_THM_TLS_CALL:
2036           case elfcpp::R_ARM_GOTRELAX:
2037           case elfcpp::R_ARM_GNU_VTENTRY:
2038           case elfcpp::R_ARM_GNU_VTINHERIT:
2039           case elfcpp::R_ARM_THM_TLS_DESCSEQ16:
2040           case elfcpp::R_ARM_THM_TLS_DESCSEQ32:
2041             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
2042           // These should have been converted to something else above.
2043           case elfcpp::R_ARM_TARGET1:
2044           case elfcpp::R_ARM_TARGET2:
2045             gold_unreachable();
2046           // Relocations that write full 32 bits.
2047           case elfcpp::R_ARM_ABS32:
2048           case elfcpp::R_ARM_REL32:
2049           case elfcpp::R_ARM_SBREL32:
2050           case elfcpp::R_ARM_GOTOFF32:
2051           case elfcpp::R_ARM_BASE_PREL:
2052           case elfcpp::R_ARM_GOT_BREL:
2053           case elfcpp::R_ARM_BASE_ABS:
2054           case elfcpp::R_ARM_ABS32_NOI:
2055           case elfcpp::R_ARM_REL32_NOI:
2056           case elfcpp::R_ARM_PLT32_ABS:
2057           case elfcpp::R_ARM_GOT_ABS:
2058           case elfcpp::R_ARM_GOT_PREL:
2059           case elfcpp::R_ARM_TLS_GD32:
2060           case elfcpp::R_ARM_TLS_LDM32:
2061           case elfcpp::R_ARM_TLS_LDO32:
2062           case elfcpp::R_ARM_TLS_IE32:
2063           case elfcpp::R_ARM_TLS_LE32:
2064             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4;
2065           default:
2066             // For all other static relocations, return RELOC_SPECIAL.
2067             return Relocatable_relocs::RELOC_SPECIAL;
2068           }
2069       }
2070   }
2071 };
2072
2073 // Utilities for manipulating integers of up to 32-bits
2074
2075 namespace utils
2076 {
2077   // Sign extend an n-bit unsigned integer stored in an uint32_t into
2078   // an int32_t.  NO_BITS must be between 1 to 32.
2079   template<int no_bits>
2080   static inline int32_t
2081   sign_extend(uint32_t bits)
2082   {
2083     gold_assert(no_bits >= 0 && no_bits <= 32);
2084     if (no_bits == 32)
2085       return static_cast<int32_t>(bits);
2086     uint32_t mask = (~((uint32_t) 0)) >> (32 - no_bits);
2087     bits &= mask;
2088     uint32_t top_bit = 1U << (no_bits - 1);
2089     int32_t as_signed = static_cast<int32_t>(bits);
2090     return (bits & top_bit) ? as_signed + (-top_bit * 2) : as_signed;
2091   }
2092
2093   // Detects overflow of an NO_BITS integer stored in a uint32_t.
2094   template<int no_bits>
2095   static inline bool
2096   has_overflow(uint32_t bits)
2097   {
2098     gold_assert(no_bits >= 0 && no_bits <= 32);
2099     if (no_bits == 32)
2100       return false;
2101     int32_t max = (1 << (no_bits - 1)) - 1;
2102     int32_t min = -(1 << (no_bits - 1));
2103     int32_t as_signed = static_cast<int32_t>(bits);
2104     return as_signed > max || as_signed < min;
2105   }
2106
2107   // Detects overflow of an NO_BITS integer stored in a uint32_t when it
2108   // fits in the given number of bits as either a signed or unsigned value.
2109   // For example, has_signed_unsigned_overflow<8> would check
2110   // -128 <= bits <= 255
2111   template<int no_bits>
2112   static inline bool
2113   has_signed_unsigned_overflow(uint32_t bits)
2114   {
2115     gold_assert(no_bits >= 2 && no_bits <= 32);
2116     if (no_bits == 32)
2117       return false;
2118     int32_t max = static_cast<int32_t>((1U << no_bits) - 1);
2119     int32_t min = -(1 << (no_bits - 1));
2120     int32_t as_signed = static_cast<int32_t>(bits);
2121     return as_signed > max || as_signed < min;
2122   }
2123
2124   // Select bits from A and B using bits in MASK.  For each n in [0..31],
2125   // the n-th bit in the result is chosen from the n-th bits of A and B.
2126   // A zero selects A and a one selects B.
2127   static inline uint32_t
2128   bit_select(uint32_t a, uint32_t b, uint32_t mask)
2129   { return (a & ~mask) | (b & mask); }
2130 };
2131
2132 template<bool big_endian>
2133 class Target_arm : public Sized_target<32, big_endian>
2134 {
2135  public:
2136   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
2137     Reloc_section;
2138
2139   // When were are relocating a stub, we pass this as the relocation number.
2140   static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
2141
2142   Target_arm()
2143     : Sized_target<32, big_endian>(&arm_info),
2144       got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
2145       copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL), 
2146       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2147       stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2148       may_use_blx_(false), should_force_pic_veneer_(false),
2149       arm_input_section_map_(), attributes_section_data_(NULL),
2150       fix_cortex_a8_(false), cortex_a8_relocs_info_()
2151   { }
2152
2153   // Virtual function which is set to return true by a target if
2154   // it can use relocation types to determine if a function's
2155   // pointer is taken.
2156   virtual bool
2157   can_check_for_function_pointers() const
2158   { return true; }
2159
2160   // Whether a section called SECTION_NAME may have function pointers to
2161   // sections not eligible for safe ICF folding.
2162   virtual bool
2163   section_may_have_icf_unsafe_pointers(const char* section_name) const
2164   {
2165     return (!is_prefix_of(".ARM.exidx", section_name)
2166             && !is_prefix_of(".ARM.extab", section_name)
2167             && Target::section_may_have_icf_unsafe_pointers(section_name));
2168   }
2169   
2170   // Whether we can use BLX.
2171   bool
2172   may_use_blx() const
2173   { return this->may_use_blx_; }
2174
2175   // Set use-BLX flag.
2176   void
2177   set_may_use_blx(bool value)
2178   { this->may_use_blx_ = value; }
2179   
2180   // Whether we force PCI branch veneers.
2181   bool
2182   should_force_pic_veneer() const
2183   { return this->should_force_pic_veneer_; }
2184
2185   // Set PIC veneer flag.
2186   void
2187   set_should_force_pic_veneer(bool value)
2188   { this->should_force_pic_veneer_ = value; }
2189   
2190   // Whether we use THUMB-2 instructions.
2191   bool
2192   using_thumb2() const
2193   {
2194     Object_attribute* attr =
2195       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2196     int arch = attr->int_value();
2197     return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2198   }
2199
2200   // Whether we use THUMB/THUMB-2 instructions only.
2201   bool
2202   using_thumb_only() const
2203   {
2204     Object_attribute* attr =
2205       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2206
2207     if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M
2208         || attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M)
2209       return true;
2210     if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2211         && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2212       return false;
2213     attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2214     return attr->int_value() == 'M';
2215   }
2216
2217   // Whether we have an NOP instruction.  If not, use mov r0, r0 instead.
2218   bool
2219   may_use_arm_nop() const
2220   {
2221     Object_attribute* attr =
2222       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2223     int arch = attr->int_value();
2224     return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2225             || arch == elfcpp::TAG_CPU_ARCH_V6K
2226             || arch == elfcpp::TAG_CPU_ARCH_V7
2227             || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2228   }
2229
2230   // Whether we have THUMB-2 NOP.W instruction.
2231   bool
2232   may_use_thumb2_nop() const
2233   {
2234     Object_attribute* attr =
2235       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2236     int arch = attr->int_value();
2237     return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2238             || arch == elfcpp::TAG_CPU_ARCH_V7
2239             || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2240   }
2241   
2242   // Process the relocations to determine unreferenced sections for 
2243   // garbage collection.
2244   void
2245   gc_process_relocs(Symbol_table* symtab,
2246                     Layout* layout,
2247                     Sized_relobj<32, big_endian>* object,
2248                     unsigned int data_shndx,
2249                     unsigned int sh_type,
2250                     const unsigned char* prelocs,
2251                     size_t reloc_count,
2252                     Output_section* output_section,
2253                     bool needs_special_offset_handling,
2254                     size_t local_symbol_count,
2255                     const unsigned char* plocal_symbols);
2256
2257   // Scan the relocations to look for symbol adjustments.
2258   void
2259   scan_relocs(Symbol_table* symtab,
2260               Layout* layout,
2261               Sized_relobj<32, big_endian>* object,
2262               unsigned int data_shndx,
2263               unsigned int sh_type,
2264               const unsigned char* prelocs,
2265               size_t reloc_count,
2266               Output_section* output_section,
2267               bool needs_special_offset_handling,
2268               size_t local_symbol_count,
2269               const unsigned char* plocal_symbols);
2270
2271   // Finalize the sections.
2272   void
2273   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2274
2275   // Return the value to use for a dynamic symbol which requires special
2276   // treatment.
2277   uint64_t
2278   do_dynsym_value(const Symbol*) const;
2279
2280   // Relocate a section.
2281   void
2282   relocate_section(const Relocate_info<32, big_endian>*,
2283                    unsigned int sh_type,
2284                    const unsigned char* prelocs,
2285                    size_t reloc_count,
2286                    Output_section* output_section,
2287                    bool needs_special_offset_handling,
2288                    unsigned char* view,
2289                    Arm_address view_address,
2290                    section_size_type view_size,
2291                    const Reloc_symbol_changes*);
2292
2293   // Scan the relocs during a relocatable link.
2294   void
2295   scan_relocatable_relocs(Symbol_table* symtab,
2296                           Layout* layout,
2297                           Sized_relobj<32, big_endian>* object,
2298                           unsigned int data_shndx,
2299                           unsigned int sh_type,
2300                           const unsigned char* prelocs,
2301                           size_t reloc_count,
2302                           Output_section* output_section,
2303                           bool needs_special_offset_handling,
2304                           size_t local_symbol_count,
2305                           const unsigned char* plocal_symbols,
2306                           Relocatable_relocs*);
2307
2308   // Relocate a section during a relocatable link.
2309   void
2310   relocate_for_relocatable(const Relocate_info<32, big_endian>*,
2311                            unsigned int sh_type,
2312                            const unsigned char* prelocs,
2313                            size_t reloc_count,
2314                            Output_section* output_section,
2315                            off_t offset_in_output_section,
2316                            const Relocatable_relocs*,
2317                            unsigned char* view,
2318                            Arm_address view_address,
2319                            section_size_type view_size,
2320                            unsigned char* reloc_view,
2321                            section_size_type reloc_view_size);
2322
2323   // Perform target-specific processing in a relocatable link.  This is
2324   // only used if we use the relocation strategy RELOC_SPECIAL.
2325   void
2326   relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2327                                unsigned int sh_type,
2328                                const unsigned char* preloc_in,
2329                                size_t relnum,
2330                                Output_section* output_section,
2331                                off_t offset_in_output_section,
2332                                unsigned char* view,
2333                                typename elfcpp::Elf_types<32>::Elf_Addr
2334                                  view_address,
2335                                section_size_type view_size,
2336                                unsigned char* preloc_out);
2337  
2338   // Return whether SYM is defined by the ABI.
2339   bool
2340   do_is_defined_by_abi(Symbol* sym) const
2341   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2342
2343   // Return whether there is a GOT section.
2344   bool
2345   has_got_section() const
2346   { return this->got_ != NULL; }
2347
2348   // Return the size of the GOT section.
2349   section_size_type
2350   got_size() const
2351   {
2352     gold_assert(this->got_ != NULL);
2353     return this->got_->data_size();
2354   }
2355
2356   // Return the number of entries in the GOT.
2357   unsigned int
2358   got_entry_count() const
2359   {
2360     if (!this->has_got_section())
2361       return 0;
2362     return this->got_size() / 4;
2363   }
2364
2365   // Return the number of entries in the PLT.
2366   unsigned int
2367   plt_entry_count() const;
2368
2369   // Return the offset of the first non-reserved PLT entry.
2370   unsigned int
2371   first_plt_entry_offset() const;
2372
2373   // Return the size of each PLT entry.
2374   unsigned int
2375   plt_entry_size() const;
2376
2377   // Map platform-specific reloc types
2378   static unsigned int
2379   get_real_reloc_type(unsigned int r_type);
2380
2381   //
2382   // Methods to support stub-generations.
2383   //
2384   
2385   // Return the stub factory
2386   const Stub_factory&
2387   stub_factory() const
2388   { return this->stub_factory_; }
2389
2390   // Make a new Arm_input_section object.
2391   Arm_input_section<big_endian>*
2392   new_arm_input_section(Relobj*, unsigned int);
2393
2394   // Find the Arm_input_section object corresponding to the SHNDX-th input
2395   // section of RELOBJ.
2396   Arm_input_section<big_endian>*
2397   find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2398
2399   // Make a new Stub_table
2400   Stub_table<big_endian>*
2401   new_stub_table(Arm_input_section<big_endian>*);
2402
2403   // Scan a section for stub generation.
2404   void
2405   scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2406                          const unsigned char*, size_t, Output_section*,
2407                          bool, const unsigned char*, Arm_address,
2408                          section_size_type);
2409
2410   // Relocate a stub. 
2411   void
2412   relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2413                 Output_section*, unsigned char*, Arm_address,
2414                 section_size_type);
2415  
2416   // Get the default ARM target.
2417   static Target_arm<big_endian>*
2418   default_target()
2419   {
2420     gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2421                 && parameters->target().is_big_endian() == big_endian);
2422     return static_cast<Target_arm<big_endian>*>(
2423              parameters->sized_target<32, big_endian>());
2424   }
2425
2426   // Whether NAME belongs to a mapping symbol.
2427   static bool
2428   is_mapping_symbol_name(const char* name)
2429   {
2430     return (name
2431             && name[0] == '$'
2432             && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2433             && (name[2] == '\0' || name[2] == '.'));
2434   }
2435
2436   // Whether we work around the Cortex-A8 erratum.
2437   bool
2438   fix_cortex_a8() const
2439   { return this->fix_cortex_a8_; }
2440
2441   // Whether we merge exidx entries in debuginfo.
2442   bool
2443   merge_exidx_entries() const
2444   { return parameters->options().merge_exidx_entries(); }
2445
2446   // Whether we fix R_ARM_V4BX relocation.
2447   // 0 - do not fix
2448   // 1 - replace with MOV instruction (armv4 target)
2449   // 2 - make interworking veneer (>= armv4t targets only)
2450   General_options::Fix_v4bx
2451   fix_v4bx() const
2452   { return parameters->options().fix_v4bx(); }
2453
2454   // Scan a span of THUMB code section for Cortex-A8 erratum.
2455   void
2456   scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2457                                   section_size_type, section_size_type,
2458                                   const unsigned char*, Arm_address);
2459
2460   // Apply Cortex-A8 workaround to a branch.
2461   void
2462   apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2463                              unsigned char*, Arm_address);
2464
2465  protected:
2466   // Make an ELF object.
2467   Object*
2468   do_make_elf_object(const std::string&, Input_file*, off_t,
2469                      const elfcpp::Ehdr<32, big_endian>& ehdr);
2470
2471   Object*
2472   do_make_elf_object(const std::string&, Input_file*, off_t,
2473                      const elfcpp::Ehdr<32, !big_endian>&)
2474   { gold_unreachable(); }
2475
2476   Object*
2477   do_make_elf_object(const std::string&, Input_file*, off_t,
2478                       const elfcpp::Ehdr<64, false>&)
2479   { gold_unreachable(); }
2480
2481   Object*
2482   do_make_elf_object(const std::string&, Input_file*, off_t,
2483                      const elfcpp::Ehdr<64, true>&)
2484   { gold_unreachable(); }
2485
2486   // Make an output section.
2487   Output_section*
2488   do_make_output_section(const char* name, elfcpp::Elf_Word type,
2489                          elfcpp::Elf_Xword flags)
2490   { return new Arm_output_section<big_endian>(name, type, flags); }
2491
2492   void
2493   do_adjust_elf_header(unsigned char* view, int len) const;
2494
2495   // We only need to generate stubs, and hence perform relaxation if we are
2496   // not doing relocatable linking.
2497   bool
2498   do_may_relax() const
2499   { return !parameters->options().relocatable(); }
2500
2501   bool
2502   do_relax(int, const Input_objects*, Symbol_table*, Layout*);
2503
2504   // Determine whether an object attribute tag takes an integer, a
2505   // string or both.
2506   int
2507   do_attribute_arg_type(int tag) const;
2508
2509   // Reorder tags during output.
2510   int
2511   do_attributes_order(int num) const;
2512
2513   // This is called when the target is selected as the default.
2514   void
2515   do_select_as_default_target()
2516   {
2517     // No locking is required since there should only be one default target.
2518     // We cannot have both the big-endian and little-endian ARM targets
2519     // as the default.
2520     gold_assert(arm_reloc_property_table == NULL);
2521     arm_reloc_property_table = new Arm_reloc_property_table();
2522   }
2523
2524  private:
2525   // The class which scans relocations.
2526   class Scan
2527   {
2528    public:
2529     Scan()
2530       : issued_non_pic_error_(false)
2531     { }
2532
2533     inline void
2534     local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2535           Sized_relobj<32, big_endian>* object,
2536           unsigned int data_shndx,
2537           Output_section* output_section,
2538           const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2539           const elfcpp::Sym<32, big_endian>& lsym);
2540
2541     inline void
2542     global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2543            Sized_relobj<32, big_endian>* object,
2544            unsigned int data_shndx,
2545            Output_section* output_section,
2546            const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2547            Symbol* gsym);
2548
2549     inline bool
2550     local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2551                                         Sized_relobj<32, big_endian>* ,
2552                                         unsigned int ,
2553                                         Output_section* ,
2554                                         const elfcpp::Rel<32, big_endian>& ,
2555                                         unsigned int ,
2556                                         const elfcpp::Sym<32, big_endian>&);
2557
2558     inline bool
2559     global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2560                                          Sized_relobj<32, big_endian>* ,
2561                                          unsigned int ,
2562                                          Output_section* ,
2563                                          const elfcpp::Rel<32, big_endian>& ,
2564                                          unsigned int , Symbol*);
2565
2566    private:
2567     static void
2568     unsupported_reloc_local(Sized_relobj<32, big_endian>*,
2569                             unsigned int r_type);
2570
2571     static void
2572     unsupported_reloc_global(Sized_relobj<32, big_endian>*,
2573                              unsigned int r_type, Symbol*);
2574
2575     void
2576     check_non_pic(Relobj*, unsigned int r_type);
2577
2578     // Almost identical to Symbol::needs_plt_entry except that it also
2579     // handles STT_ARM_TFUNC.
2580     static bool
2581     symbol_needs_plt_entry(const Symbol* sym)
2582     {
2583       // An undefined symbol from an executable does not need a PLT entry.
2584       if (sym->is_undefined() && !parameters->options().shared())
2585         return false;
2586
2587       return (!parameters->doing_static_link()
2588               && (sym->type() == elfcpp::STT_FUNC
2589                   || sym->type() == elfcpp::STT_ARM_TFUNC)
2590               && (sym->is_from_dynobj()
2591                   || sym->is_undefined()
2592                   || sym->is_preemptible()));
2593     }
2594
2595     inline bool
2596     possible_function_pointer_reloc(unsigned int r_type);
2597
2598     // Whether we have issued an error about a non-PIC compilation.
2599     bool issued_non_pic_error_;
2600   };
2601
2602   // The class which implements relocation.
2603   class Relocate
2604   {
2605    public:
2606     Relocate()
2607     { }
2608
2609     ~Relocate()
2610     { }
2611
2612     // Return whether the static relocation needs to be applied.
2613     inline bool
2614     should_apply_static_reloc(const Sized_symbol<32>* gsym,
2615                               int ref_flags,
2616                               bool is_32bit,
2617                               Output_section* output_section);
2618
2619     // Do a relocation.  Return false if the caller should not issue
2620     // any warnings about this relocation.
2621     inline bool
2622     relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2623              Output_section*,  size_t relnum,
2624              const elfcpp::Rel<32, big_endian>&,
2625              unsigned int r_type, const Sized_symbol<32>*,
2626              const Symbol_value<32>*,
2627              unsigned char*, Arm_address,
2628              section_size_type);
2629
2630     // Return whether we want to pass flag NON_PIC_REF for this
2631     // reloc.  This means the relocation type accesses a symbol not via
2632     // GOT or PLT.
2633     static inline bool
2634     reloc_is_non_pic(unsigned int r_type)
2635     {
2636       switch (r_type)
2637         {
2638         // These relocation types reference GOT or PLT entries explicitly.
2639         case elfcpp::R_ARM_GOT_BREL:
2640         case elfcpp::R_ARM_GOT_ABS:
2641         case elfcpp::R_ARM_GOT_PREL:
2642         case elfcpp::R_ARM_GOT_BREL12:
2643         case elfcpp::R_ARM_PLT32_ABS:
2644         case elfcpp::R_ARM_TLS_GD32:
2645         case elfcpp::R_ARM_TLS_LDM32:
2646         case elfcpp::R_ARM_TLS_IE32:
2647         case elfcpp::R_ARM_TLS_IE12GP:
2648
2649         // These relocate types may use PLT entries.
2650         case elfcpp::R_ARM_CALL:
2651         case elfcpp::R_ARM_THM_CALL:
2652         case elfcpp::R_ARM_JUMP24:
2653         case elfcpp::R_ARM_THM_JUMP24:
2654         case elfcpp::R_ARM_THM_JUMP19:
2655         case elfcpp::R_ARM_PLT32:
2656         case elfcpp::R_ARM_THM_XPC22:
2657         case elfcpp::R_ARM_PREL31:
2658         case elfcpp::R_ARM_SBREL31:
2659           return false;
2660
2661         default:
2662           return true;
2663         }
2664     }
2665
2666    private:
2667     // Do a TLS relocation.
2668     inline typename Arm_relocate_functions<big_endian>::Status
2669     relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2670                  size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2671                  const Sized_symbol<32>*, const Symbol_value<32>*,
2672                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2673                  section_size_type);
2674
2675   };
2676
2677   // A class which returns the size required for a relocation type,
2678   // used while scanning relocs during a relocatable link.
2679   class Relocatable_size_for_reloc
2680   {
2681    public:
2682     unsigned int
2683     get_size_for_reloc(unsigned int, Relobj*);
2684   };
2685
2686   // Adjust TLS relocation type based on the options and whether this
2687   // is a local symbol.
2688   static tls::Tls_optimization
2689   optimize_tls_reloc(bool is_final, int r_type);
2690
2691   // Get the GOT section, creating it if necessary.
2692   Arm_output_data_got<big_endian>*
2693   got_section(Symbol_table*, Layout*);
2694
2695   // Get the GOT PLT section.
2696   Output_data_space*
2697   got_plt_section() const
2698   {
2699     gold_assert(this->got_plt_ != NULL);
2700     return this->got_plt_;
2701   }
2702
2703   // Create a PLT entry for a global symbol.
2704   void
2705   make_plt_entry(Symbol_table*, Layout*, Symbol*);
2706
2707   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2708   void
2709   define_tls_base_symbol(Symbol_table*, Layout*);
2710
2711   // Create a GOT entry for the TLS module index.
2712   unsigned int
2713   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2714                       Sized_relobj<32, big_endian>* object);
2715
2716   // Get the PLT section.
2717   const Output_data_plt_arm<big_endian>*
2718   plt_section() const
2719   {
2720     gold_assert(this->plt_ != NULL);
2721     return this->plt_;
2722   }
2723
2724   // Get the dynamic reloc section, creating it if necessary.
2725   Reloc_section*
2726   rel_dyn_section(Layout*);
2727
2728   // Get the section to use for TLS_DESC relocations.
2729   Reloc_section*
2730   rel_tls_desc_section(Layout*) const;
2731
2732   // Return true if the symbol may need a COPY relocation.
2733   // References from an executable object to non-function symbols
2734   // defined in a dynamic object may need a COPY relocation.
2735   bool
2736   may_need_copy_reloc(Symbol* gsym)
2737   {
2738     return (gsym->type() != elfcpp::STT_ARM_TFUNC
2739             && gsym->may_need_copy_reloc());
2740   }
2741
2742   // Add a potential copy relocation.
2743   void
2744   copy_reloc(Symbol_table* symtab, Layout* layout,
2745              Sized_relobj<32, big_endian>* object,
2746              unsigned int shndx, Output_section* output_section,
2747              Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2748   {
2749     this->copy_relocs_.copy_reloc(symtab, layout,
2750                                   symtab->get_sized_symbol<32>(sym),
2751                                   object, shndx, output_section, reloc,
2752                                   this->rel_dyn_section(layout));
2753   }
2754
2755   // Whether two EABI versions are compatible.
2756   static bool
2757   are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2758
2759   // Merge processor-specific flags from input object and those in the ELF
2760   // header of the output.
2761   void
2762   merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2763
2764   // Get the secondary compatible architecture.
2765   static int
2766   get_secondary_compatible_arch(const Attributes_section_data*);
2767
2768   // Set the secondary compatible architecture.
2769   static void
2770   set_secondary_compatible_arch(Attributes_section_data*, int);
2771
2772   static int
2773   tag_cpu_arch_combine(const char*, int, int*, int, int);
2774
2775   // Helper to print AEABI enum tag value.
2776   static std::string
2777   aeabi_enum_name(unsigned int);
2778
2779   // Return string value for TAG_CPU_name.
2780   static std::string
2781   tag_cpu_name_value(unsigned int);
2782
2783   // Merge object attributes from input object and those in the output.
2784   void
2785   merge_object_attributes(const char*, const Attributes_section_data*);
2786
2787   // Helper to get an AEABI object attribute
2788   Object_attribute*
2789   get_aeabi_object_attribute(int tag) const
2790   {
2791     Attributes_section_data* pasd = this->attributes_section_data_;
2792     gold_assert(pasd != NULL);
2793     Object_attribute* attr =
2794       pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2795     gold_assert(attr != NULL);
2796     return attr;
2797   }
2798
2799   //
2800   // Methods to support stub-generations.
2801   //
2802
2803   // Group input sections for stub generation.
2804   void
2805   group_sections(Layout*, section_size_type, bool);
2806
2807   // Scan a relocation for stub generation.
2808   void
2809   scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2810                       const Sized_symbol<32>*, unsigned int,
2811                       const Symbol_value<32>*,
2812                       elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2813
2814   // Scan a relocation section for stub.
2815   template<int sh_type>
2816   void
2817   scan_reloc_section_for_stubs(
2818       const Relocate_info<32, big_endian>* relinfo,
2819       const unsigned char* prelocs,
2820       size_t reloc_count,
2821       Output_section* output_section,
2822       bool needs_special_offset_handling,
2823       const unsigned char* view,
2824       elfcpp::Elf_types<32>::Elf_Addr view_address,
2825       section_size_type);
2826
2827   // Fix .ARM.exidx section coverage.
2828   void
2829   fix_exidx_coverage(Layout*, const Input_objects*,
2830                      Arm_output_section<big_endian>*, Symbol_table*);
2831
2832   // Functors for STL set.
2833   struct output_section_address_less_than
2834   {
2835     bool
2836     operator()(const Output_section* s1, const Output_section* s2) const
2837     { return s1->address() < s2->address(); }
2838   };
2839
2840   // Information about this specific target which we pass to the
2841   // general Target structure.
2842   static const Target::Target_info arm_info;
2843
2844   // The types of GOT entries needed for this platform.
2845   // These values are exposed to the ABI in an incremental link.
2846   // Do not renumber existing values without changing the version
2847   // number of the .gnu_incremental_inputs section.
2848   enum Got_type
2849   {
2850     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
2851     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
2852     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
2853     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
2854     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
2855   };
2856
2857   typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2858
2859   // Map input section to Arm_input_section.
2860   typedef Unordered_map<Section_id,
2861                         Arm_input_section<big_endian>*,
2862                         Section_id_hash>
2863           Arm_input_section_map;
2864     
2865   // Map output addresses to relocs for Cortex-A8 erratum.
2866   typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2867           Cortex_a8_relocs_info;
2868
2869   // The GOT section.
2870   Arm_output_data_got<big_endian>* got_;
2871   // The PLT section.
2872   Output_data_plt_arm<big_endian>* plt_;
2873   // The GOT PLT section.
2874   Output_data_space* got_plt_;
2875   // The dynamic reloc section.
2876   Reloc_section* rel_dyn_;
2877   // Relocs saved to avoid a COPY reloc.
2878   Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2879   // Space for variables copied with a COPY reloc.
2880   Output_data_space* dynbss_;
2881   // Offset of the GOT entry for the TLS module index.
2882   unsigned int got_mod_index_offset_;
2883   // True if the _TLS_MODULE_BASE_ symbol has been defined.
2884   bool tls_base_symbol_defined_;
2885   // Vector of Stub_tables created.
2886   Stub_table_list stub_tables_;
2887   // Stub factory.
2888   const Stub_factory &stub_factory_;
2889   // Whether we can use BLX.
2890   bool may_use_blx_;
2891   // Whether we force PIC branch veneers.
2892   bool should_force_pic_veneer_;
2893   // Map for locating Arm_input_sections.
2894   Arm_input_section_map arm_input_section_map_;
2895   // Attributes section data in output.
2896   Attributes_section_data* attributes_section_data_;
2897   // Whether we want to fix code for Cortex-A8 erratum.
2898   bool fix_cortex_a8_;
2899   // Map addresses to relocs for Cortex-A8 erratum.
2900   Cortex_a8_relocs_info cortex_a8_relocs_info_;
2901 };
2902
2903 template<bool big_endian>
2904 const Target::Target_info Target_arm<big_endian>::arm_info =
2905 {
2906   32,                   // size
2907   big_endian,           // is_big_endian
2908   elfcpp::EM_ARM,       // machine_code
2909   false,                // has_make_symbol
2910   false,                // has_resolve
2911   false,                // has_code_fill
2912   true,                 // is_default_stack_executable
2913   '\0',                 // wrap_char
2914   "/usr/lib/libc.so.1", // dynamic_linker
2915   0x8000,               // default_text_segment_address
2916   0x1000,               // abi_pagesize (overridable by -z max-page-size)
2917   0x1000,               // common_pagesize (overridable by -z common-page-size)
2918   elfcpp::SHN_UNDEF,    // small_common_shndx
2919   elfcpp::SHN_UNDEF,    // large_common_shndx
2920   0,                    // small_common_section_flags
2921   0,                    // large_common_section_flags
2922   ".ARM.attributes",    // attributes_section
2923   "aeabi"               // attributes_vendor
2924 };
2925
2926 // Arm relocate functions class
2927 //
2928
2929 template<bool big_endian>
2930 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2931 {
2932  public:
2933   typedef enum
2934   {
2935     STATUS_OKAY,        // No error during relocation.
2936     STATUS_OVERFLOW,    // Relocation oveflow.
2937     STATUS_BAD_RELOC    // Relocation cannot be applied.
2938   } Status;
2939
2940  private:
2941   typedef Relocate_functions<32, big_endian> Base;
2942   typedef Arm_relocate_functions<big_endian> This;
2943
2944   // Encoding of imm16 argument for movt and movw ARM instructions
2945   // from ARM ARM:
2946   //     
2947   //     imm16 := imm4 | imm12
2948   //
2949   //  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 
2950   // +-------+---------------+-------+-------+-----------------------+
2951   // |       |               |imm4   |       |imm12                  |
2952   // +-------+---------------+-------+-------+-----------------------+
2953
2954   // Extract the relocation addend from VAL based on the ARM
2955   // instruction encoding described above.
2956   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2957   extract_arm_movw_movt_addend(
2958       typename elfcpp::Swap<32, big_endian>::Valtype val)
2959   {
2960     // According to the Elf ABI for ARM Architecture the immediate
2961     // field is sign-extended to form the addend.
2962     return utils::sign_extend<16>(((val >> 4) & 0xf000) | (val & 0xfff));
2963   }
2964
2965   // Insert X into VAL based on the ARM instruction encoding described
2966   // above.
2967   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2968   insert_val_arm_movw_movt(
2969       typename elfcpp::Swap<32, big_endian>::Valtype val,
2970       typename elfcpp::Swap<32, big_endian>::Valtype x)
2971   {
2972     val &= 0xfff0f000;
2973     val |= x & 0x0fff;
2974     val |= (x & 0xf000) << 4;
2975     return val;
2976   }
2977
2978   // Encoding of imm16 argument for movt and movw Thumb2 instructions
2979   // from ARM ARM:
2980   //     
2981   //     imm16 := imm4 | i | imm3 | imm8
2982   //
2983   //  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 
2984   // +---------+-+-----------+-------++-+-----+-------+---------------+
2985   // |         |i|           |imm4   || |imm3 |       |imm8           |
2986   // +---------+-+-----------+-------++-+-----+-------+---------------+
2987
2988   // Extract the relocation addend from VAL based on the Thumb2
2989   // instruction encoding described above.
2990   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2991   extract_thumb_movw_movt_addend(
2992       typename elfcpp::Swap<32, big_endian>::Valtype val)
2993   {
2994     // According to the Elf ABI for ARM Architecture the immediate
2995     // field is sign-extended to form the addend.
2996     return utils::sign_extend<16>(((val >> 4) & 0xf000)
2997                                   | ((val >> 15) & 0x0800)
2998                                   | ((val >> 4) & 0x0700)
2999                                   | (val & 0x00ff));
3000   }
3001
3002   // Insert X into VAL based on the Thumb2 instruction encoding
3003   // described above.
3004   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3005   insert_val_thumb_movw_movt(
3006       typename elfcpp::Swap<32, big_endian>::Valtype val,
3007       typename elfcpp::Swap<32, big_endian>::Valtype x)
3008   {
3009     val &= 0xfbf08f00;
3010     val |= (x & 0xf000) << 4;
3011     val |= (x & 0x0800) << 15;
3012     val |= (x & 0x0700) << 4;
3013     val |= (x & 0x00ff);
3014     return val;
3015   }
3016
3017   // Calculate the smallest constant Kn for the specified residual.
3018   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3019   static uint32_t
3020   calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3021   {
3022     int32_t msb;
3023
3024     if (residual == 0)
3025       return 0;
3026     // Determine the most significant bit in the residual and
3027     // align the resulting value to a 2-bit boundary.
3028     for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3029       ;
3030     // The desired shift is now (msb - 6), or zero, whichever
3031     // is the greater.
3032     return (((msb - 6) < 0) ? 0 : (msb - 6));
3033   }
3034
3035   // Calculate the final residual for the specified group index.
3036   // If the passed group index is less than zero, the method will return
3037   // the value of the specified residual without any change.
3038   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3039   static typename elfcpp::Swap<32, big_endian>::Valtype
3040   calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3041                     const int group)
3042   {
3043     for (int n = 0; n <= group; n++)
3044       {
3045         // Calculate which part of the value to mask.
3046         uint32_t shift = calc_grp_kn(residual);
3047         // Calculate the residual for the next time around.
3048         residual &= ~(residual & (0xff << shift));
3049       }
3050
3051     return residual;
3052   }
3053
3054   // Calculate the value of Gn for the specified group index.
3055   // We return it in the form of an encoded constant-and-rotation.
3056   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3057   static typename elfcpp::Swap<32, big_endian>::Valtype
3058   calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3059               const int group)
3060   {
3061     typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3062     uint32_t shift = 0;
3063
3064     for (int n = 0; n <= group; n++)
3065       {
3066         // Calculate which part of the value to mask.
3067         shift = calc_grp_kn(residual);
3068         // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3069         gn = residual & (0xff << shift);
3070         // Calculate the residual for the next time around.
3071         residual &= ~gn;
3072       }
3073     // Return Gn in the form of an encoded constant-and-rotation.
3074     return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3075   }
3076
3077  public:
3078   // Handle ARM long branches.
3079   static typename This::Status
3080   arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3081                     unsigned char*, const Sized_symbol<32>*,
3082                     const Arm_relobj<big_endian>*, unsigned int,
3083                     const Symbol_value<32>*, Arm_address, Arm_address, bool);
3084
3085   // Handle THUMB long branches.
3086   static typename This::Status
3087   thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3088                       unsigned char*, const Sized_symbol<32>*,
3089                       const Arm_relobj<big_endian>*, unsigned int,
3090                       const Symbol_value<32>*, Arm_address, Arm_address, bool);
3091
3092
3093   // Return the branch offset of a 32-bit THUMB branch.
3094   static inline int32_t
3095   thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3096   {
3097     // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3098     // involving the J1 and J2 bits.
3099     uint32_t s = (upper_insn & (1U << 10)) >> 10;
3100     uint32_t upper = upper_insn & 0x3ffU;
3101     uint32_t lower = lower_insn & 0x7ffU;
3102     uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3103     uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3104     uint32_t i1 = j1 ^ s ? 0 : 1;
3105     uint32_t i2 = j2 ^ s ? 0 : 1;
3106
3107     return utils::sign_extend<25>((s << 24) | (i1 << 23) | (i2 << 22)
3108                                   | (upper << 12) | (lower << 1));
3109   }
3110
3111   // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3112   // UPPER_INSN is the original upper instruction of the branch.  Caller is
3113   // responsible for overflow checking and BLX offset adjustment.
3114   static inline uint16_t
3115   thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3116   {
3117     uint32_t s = offset < 0 ? 1 : 0;
3118     uint32_t bits = static_cast<uint32_t>(offset);
3119     return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3120   }
3121
3122   // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3123   // LOWER_INSN is the original lower instruction of the branch.  Caller is
3124   // responsible for overflow checking and BLX offset adjustment.
3125   static inline uint16_t
3126   thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3127   {
3128     uint32_t s = offset < 0 ? 1 : 0;
3129     uint32_t bits = static_cast<uint32_t>(offset);
3130     return ((lower_insn & ~0x2fffU)
3131             | ((((bits >> 23) & 1) ^ !s) << 13)
3132             | ((((bits >> 22) & 1) ^ !s) << 11)
3133             | ((bits >> 1) & 0x7ffU));
3134   }
3135
3136   // Return the branch offset of a 32-bit THUMB conditional branch.
3137   static inline int32_t
3138   thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3139   {
3140     uint32_t s = (upper_insn & 0x0400U) >> 10;
3141     uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3142     uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3143     uint32_t lower = (lower_insn & 0x07ffU);
3144     uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3145
3146     return utils::sign_extend<21>((upper << 12) | (lower << 1));
3147   }
3148
3149   // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3150   // instruction.  UPPER_INSN is the original upper instruction of the branch.
3151   // Caller is responsible for overflow checking.
3152   static inline uint16_t
3153   thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3154   {
3155     uint32_t s = offset < 0 ? 1 : 0;
3156     uint32_t bits = static_cast<uint32_t>(offset);
3157     return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3158   }
3159
3160   // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3161   // instruction.  LOWER_INSN is the original lower instruction of the branch.
3162   // Caller is reponsible for overflow checking.
3163   static inline uint16_t
3164   thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3165   {
3166     uint32_t bits = static_cast<uint32_t>(offset);
3167     uint32_t j2 = (bits & 0x00080000U) >> 19;
3168     uint32_t j1 = (bits & 0x00040000U) >> 18;
3169     uint32_t lo = (bits & 0x00000ffeU) >> 1;
3170
3171     return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3172   }
3173
3174   // R_ARM_ABS8: S + A
3175   static inline typename This::Status
3176   abs8(unsigned char* view,
3177        const Sized_relobj<32, big_endian>* object,
3178        const Symbol_value<32>* psymval)
3179   {
3180     typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3181     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3182     Valtype* wv = reinterpret_cast<Valtype*>(view);
3183     Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3184     Reltype addend = utils::sign_extend<8>(val);
3185     Reltype x = psymval->value(object, addend);
3186     val = utils::bit_select(val, x, 0xffU);
3187     elfcpp::Swap<8, big_endian>::writeval(wv, val);
3188
3189     // R_ARM_ABS8 permits signed or unsigned results.
3190     int signed_x = static_cast<int32_t>(x);
3191     return ((signed_x < -128 || signed_x > 255)
3192             ? This::STATUS_OVERFLOW
3193             : This::STATUS_OKAY);
3194   }
3195
3196   // R_ARM_THM_ABS5: S + A
3197   static inline typename This::Status
3198   thm_abs5(unsigned char* view,
3199        const Sized_relobj<32, big_endian>* object,
3200        const Symbol_value<32>* psymval)
3201   {
3202     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3203     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3204     Valtype* wv = reinterpret_cast<Valtype*>(view);
3205     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3206     Reltype addend = (val & 0x7e0U) >> 6;
3207     Reltype x = psymval->value(object, addend);
3208     val = utils::bit_select(val, x << 6, 0x7e0U);
3209     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3210
3211     // R_ARM_ABS16 permits signed or unsigned results.
3212     int signed_x = static_cast<int32_t>(x);
3213     return ((signed_x < -32768 || signed_x > 65535)
3214             ? This::STATUS_OVERFLOW
3215             : This::STATUS_OKAY);
3216   }
3217
3218   // R_ARM_ABS12: S + A
3219   static inline typename This::Status
3220   abs12(unsigned char* view,
3221         const Sized_relobj<32, big_endian>* object,
3222         const Symbol_value<32>* psymval)
3223   {
3224     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3225     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3226     Valtype* wv = reinterpret_cast<Valtype*>(view);
3227     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3228     Reltype addend = val & 0x0fffU;
3229     Reltype x = psymval->value(object, addend);
3230     val = utils::bit_select(val, x, 0x0fffU);
3231     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3232     return (utils::has_overflow<12>(x)
3233             ? This::STATUS_OVERFLOW
3234             : This::STATUS_OKAY);
3235   }
3236
3237   // R_ARM_ABS16: S + A
3238   static inline typename This::Status
3239   abs16(unsigned char* view,
3240         const Sized_relobj<32, big_endian>* object,
3241         const Symbol_value<32>* psymval)
3242   {
3243     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3244     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3245     Valtype* wv = reinterpret_cast<Valtype*>(view);
3246     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3247     Reltype addend = utils::sign_extend<16>(val);
3248     Reltype x = psymval->value(object, addend);
3249     val = utils::bit_select(val, x, 0xffffU);
3250     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3251     return (utils::has_signed_unsigned_overflow<16>(x)
3252             ? This::STATUS_OVERFLOW
3253             : This::STATUS_OKAY);
3254   }
3255
3256   // R_ARM_ABS32: (S + A) | T
3257   static inline typename This::Status
3258   abs32(unsigned char* view,
3259         const Sized_relobj<32, big_endian>* object,
3260         const Symbol_value<32>* psymval,
3261         Arm_address thumb_bit)
3262   {
3263     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3264     Valtype* wv = reinterpret_cast<Valtype*>(view);
3265     Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
3266     Valtype x = psymval->value(object, addend) | thumb_bit;
3267     elfcpp::Swap<32, big_endian>::writeval(wv, x);
3268     return This::STATUS_OKAY;
3269   }
3270
3271   // R_ARM_REL32: (S + A) | T - P
3272   static inline typename This::Status
3273   rel32(unsigned char* view,
3274         const Sized_relobj<32, big_endian>* object,
3275         const Symbol_value<32>* psymval,
3276         Arm_address address,
3277         Arm_address thumb_bit)
3278   {
3279     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3280     Valtype* wv = reinterpret_cast<Valtype*>(view);
3281     Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
3282     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3283     elfcpp::Swap<32, big_endian>::writeval(wv, x);
3284     return This::STATUS_OKAY;
3285   }
3286
3287   // R_ARM_THM_JUMP24: (S + A) | T - P
3288   static typename This::Status
3289   thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3290              const Symbol_value<32>* psymval, Arm_address address,
3291              Arm_address thumb_bit);
3292
3293   // R_ARM_THM_JUMP6: S + A â€“ P
3294   static inline typename This::Status
3295   thm_jump6(unsigned char* view,
3296             const Sized_relobj<32, big_endian>* object,
3297             const Symbol_value<32>* psymval,
3298             Arm_address address)
3299   {
3300     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3301     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3302     Valtype* wv = reinterpret_cast<Valtype*>(view);
3303     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3304     // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3305     Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3306     Reltype x = (psymval->value(object, addend) - address);
3307     val = (val & 0xfd07) | ((x  & 0x0040) << 3) | ((val & 0x003e) << 2);
3308     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3309     // CZB does only forward jumps.
3310     return ((x > 0x007e)
3311             ? This::STATUS_OVERFLOW
3312             : This::STATUS_OKAY);
3313   }
3314
3315   // R_ARM_THM_JUMP8: S + A â€“ P
3316   static inline typename This::Status
3317   thm_jump8(unsigned char* view,
3318             const Sized_relobj<32, big_endian>* object,
3319             const Symbol_value<32>* psymval,
3320             Arm_address address)
3321   {
3322     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3323     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3324     Valtype* wv = reinterpret_cast<Valtype*>(view);
3325     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3326     Reltype addend = utils::sign_extend<8>((val & 0x00ff) << 1);
3327     Reltype x = (psymval->value(object, addend) - address);
3328     elfcpp::Swap<16, big_endian>::writeval(wv, (val & 0xff00) | ((x & 0x01fe) >> 1));
3329     return (utils::has_overflow<8>(x)
3330             ? This::STATUS_OVERFLOW
3331             : This::STATUS_OKAY);
3332   }
3333
3334   // R_ARM_THM_JUMP11: S + A â€“ P
3335   static inline typename This::Status
3336   thm_jump11(unsigned char* view,
3337             const Sized_relobj<32, big_endian>* object,
3338             const Symbol_value<32>* psymval,
3339             Arm_address address)
3340   {
3341     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3342     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3343     Valtype* wv = reinterpret_cast<Valtype*>(view);
3344     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3345     Reltype addend = utils::sign_extend<11>((val & 0x07ff) << 1);
3346     Reltype x = (psymval->value(object, addend) - address);
3347     elfcpp::Swap<16, big_endian>::writeval(wv, (val & 0xf800) | ((x & 0x0ffe) >> 1));
3348     return (utils::has_overflow<11>(x)
3349             ? This::STATUS_OVERFLOW
3350             : This::STATUS_OKAY);
3351   }
3352
3353   // R_ARM_BASE_PREL: B(S) + A - P
3354   static inline typename This::Status
3355   base_prel(unsigned char* view,
3356             Arm_address origin,
3357             Arm_address address)
3358   {
3359     Base::rel32(view, origin - address);
3360     return STATUS_OKAY;
3361   }
3362
3363   // R_ARM_BASE_ABS: B(S) + A
3364   static inline typename This::Status
3365   base_abs(unsigned char* view,
3366            Arm_address origin)
3367   {
3368     Base::rel32(view, origin);
3369     return STATUS_OKAY;
3370   }
3371
3372   // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3373   static inline typename This::Status
3374   got_brel(unsigned char* view,
3375            typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3376   {
3377     Base::rel32(view, got_offset);
3378     return This::STATUS_OKAY;
3379   }
3380
3381   // R_ARM_GOT_PREL: GOT(S) + A - P
3382   static inline typename This::Status
3383   got_prel(unsigned char* view,
3384            Arm_address got_entry,
3385            Arm_address address)
3386   {
3387     Base::rel32(view, got_entry - address);
3388     return This::STATUS_OKAY;
3389   }
3390
3391   // R_ARM_PREL: (S + A) | T - P
3392   static inline typename This::Status
3393   prel31(unsigned char* view,
3394          const Sized_relobj<32, big_endian>* object,
3395          const Symbol_value<32>* psymval,
3396          Arm_address address,
3397          Arm_address thumb_bit)
3398   {
3399     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3400     Valtype* wv = reinterpret_cast<Valtype*>(view);
3401     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3402     Valtype addend = utils::sign_extend<31>(val);
3403     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3404     val = utils::bit_select(val, x, 0x7fffffffU);
3405     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3406     return (utils::has_overflow<31>(x) ?
3407             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3408   }
3409
3410   // R_ARM_MOVW_ABS_NC: (S + A) | T     (relative address base is )
3411   // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3412   // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3413   // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3414   static inline typename This::Status
3415   movw(unsigned char* view,
3416        const Sized_relobj<32, big_endian>* object,
3417        const Symbol_value<32>* psymval,
3418        Arm_address relative_address_base,
3419        Arm_address thumb_bit,
3420        bool check_overflow)
3421   {
3422     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3423     Valtype* wv = reinterpret_cast<Valtype*>(view);
3424     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3425     Valtype addend = This::extract_arm_movw_movt_addend(val);
3426     Valtype x = ((psymval->value(object, addend) | thumb_bit)
3427                  - relative_address_base);
3428     val = This::insert_val_arm_movw_movt(val, x);
3429     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3430     return ((check_overflow && utils::has_overflow<16>(x))
3431             ? This::STATUS_OVERFLOW
3432             : This::STATUS_OKAY);
3433   }
3434
3435   // R_ARM_MOVT_ABS: S + A      (relative address base is 0)
3436   // R_ARM_MOVT_PREL: S + A - P
3437   // R_ARM_MOVT_BREL: S + A - B(S)
3438   static inline typename This::Status
3439   movt(unsigned char* view,
3440        const Sized_relobj<32, big_endian>* object,
3441        const Symbol_value<32>* psymval,
3442        Arm_address relative_address_base)
3443   {
3444     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3445     Valtype* wv = reinterpret_cast<Valtype*>(view);
3446     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3447     Valtype addend = This::extract_arm_movw_movt_addend(val);
3448     Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3449     val = This::insert_val_arm_movw_movt(val, x);
3450     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3451     // FIXME: IHI0044D says that we should check for overflow.
3452     return This::STATUS_OKAY;
3453   }
3454
3455   // R_ARM_THM_MOVW_ABS_NC: S + A | T           (relative_address_base is 0)
3456   // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3457   // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3458   // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3459   static inline typename This::Status
3460   thm_movw(unsigned char* view,
3461            const Sized_relobj<32, big_endian>* object,
3462            const Symbol_value<32>* psymval,
3463            Arm_address relative_address_base,
3464            Arm_address thumb_bit,
3465            bool check_overflow)
3466   {
3467     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3468     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3469     Valtype* wv = reinterpret_cast<Valtype*>(view);
3470     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3471                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3472     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3473     Reltype x =
3474       (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3475     val = This::insert_val_thumb_movw_movt(val, x);
3476     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3477     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3478     return ((check_overflow && utils::has_overflow<16>(x))
3479             ? This::STATUS_OVERFLOW
3480             : This::STATUS_OKAY);
3481   }
3482
3483   // R_ARM_THM_MOVT_ABS: S + A          (relative address base is 0)
3484   // R_ARM_THM_MOVT_PREL: S + A - P
3485   // R_ARM_THM_MOVT_BREL: S + A - B(S)
3486   static inline typename This::Status
3487   thm_movt(unsigned char* view,
3488            const Sized_relobj<32, big_endian>* object,
3489            const Symbol_value<32>* psymval,
3490            Arm_address relative_address_base)
3491   {
3492     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3493     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3494     Valtype* wv = reinterpret_cast<Valtype*>(view);
3495     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3496                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3497     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3498     Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3499     val = This::insert_val_thumb_movw_movt(val, x);
3500     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3501     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3502     return This::STATUS_OKAY;
3503   }
3504
3505   // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3506   static inline typename This::Status
3507   thm_alu11(unsigned char* view,
3508             const Sized_relobj<32, big_endian>* object,
3509             const Symbol_value<32>* psymval,
3510             Arm_address address,
3511             Arm_address thumb_bit)
3512   {
3513     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3514     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3515     Valtype* wv = reinterpret_cast<Valtype*>(view);
3516     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3517                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3518
3519     //        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
3520     // -----------------------------------------------------------------------
3521     // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd     |imm8
3522     // ADDW   1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd     |imm8
3523     // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd     |imm8
3524     // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd     |imm8
3525     // SUBW   1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd     |imm8
3526     // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd     |imm8
3527
3528     // Determine a sign for the addend.
3529     const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3530                       || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3531     // Thumb2 addend encoding:
3532     // imm12 := i | imm3 | imm8
3533     int32_t addend = (insn & 0xff)
3534                      | ((insn & 0x00007000) >> 4)
3535                      | ((insn & 0x04000000) >> 15);
3536     // Apply a sign to the added.
3537     addend *= sign;
3538
3539     int32_t x = (psymval->value(object, addend) | thumb_bit)
3540                 - (address & 0xfffffffc);
3541     Reltype val = abs(x);
3542     // Mask out the value and a distinct part of the ADD/SUB opcode
3543     // (bits 7:5 of opword).
3544     insn = (insn & 0xfb0f8f00)
3545            | (val & 0xff)
3546            | ((val & 0x700) << 4)
3547            | ((val & 0x800) << 15);
3548     // Set the opcode according to whether the value to go in the
3549     // place is negative.
3550     if (x < 0)
3551       insn |= 0x00a00000;
3552
3553     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3554     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3555     return ((val > 0xfff) ?
3556             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3557   }
3558
3559   // R_ARM_THM_PC8: S + A - Pa (Thumb)
3560   static inline typename This::Status
3561   thm_pc8(unsigned char* view,
3562           const Sized_relobj<32, big_endian>* object,
3563           const Symbol_value<32>* psymval,
3564           Arm_address address)
3565   {
3566     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3567     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3568     Valtype* wv = reinterpret_cast<Valtype*>(view);
3569     Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3570     Reltype addend = ((insn & 0x00ff) << 2);
3571     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3572     Reltype val = abs(x);
3573     insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3574
3575     elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3576     return ((val > 0x03fc)
3577             ? This::STATUS_OVERFLOW
3578             : This::STATUS_OKAY);
3579   }
3580
3581   // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3582   static inline typename This::Status
3583   thm_pc12(unsigned char* view,
3584            const Sized_relobj<32, big_endian>* object,
3585            const Symbol_value<32>* psymval,
3586            Arm_address address)
3587   {
3588     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3589     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3590     Valtype* wv = reinterpret_cast<Valtype*>(view);
3591     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3592                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3593     // Determine a sign for the addend (positive if the U bit is 1).
3594     const int sign = (insn & 0x00800000) ? 1 : -1;
3595     int32_t addend = (insn & 0xfff);
3596     // Apply a sign to the added.
3597     addend *= sign;
3598
3599     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3600     Reltype val = abs(x);
3601     // Mask out and apply the value and the U bit.
3602     insn = (insn & 0xff7ff000) | (val & 0xfff);
3603     // Set the U bit according to whether the value to go in the
3604     // place is positive.
3605     if (x >= 0)
3606       insn |= 0x00800000;
3607
3608     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3609     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3610     return ((val > 0xfff) ?
3611             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3612   }
3613
3614   // R_ARM_V4BX
3615   static inline typename This::Status
3616   v4bx(const Relocate_info<32, big_endian>* relinfo,
3617        unsigned char* view,
3618        const Arm_relobj<big_endian>* object,
3619        const Arm_address address,
3620        const bool is_interworking)
3621   {
3622
3623     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3624     Valtype* wv = reinterpret_cast<Valtype*>(view);
3625     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3626
3627     // Ensure that we have a BX instruction.
3628     gold_assert((val & 0x0ffffff0) == 0x012fff10);
3629     const uint32_t reg = (val & 0xf);
3630     if (is_interworking && reg != 0xf)
3631       {
3632         Stub_table<big_endian>* stub_table =
3633             object->stub_table(relinfo->data_shndx);
3634         gold_assert(stub_table != NULL);
3635
3636         Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3637         gold_assert(stub != NULL);
3638
3639         int32_t veneer_address =
3640             stub_table->address() + stub->offset() - 8 - address;
3641         gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3642                     && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3643         // Replace with a branch to veneer (B <addr>)
3644         val = (val & 0xf0000000) | 0x0a000000
3645               | ((veneer_address >> 2) & 0x00ffffff);
3646       }
3647     else
3648       {
3649         // Preserve Rm (lowest four bits) and the condition code
3650         // (highest four bits). Other bits encode MOV PC,Rm.
3651         val = (val & 0xf000000f) | 0x01a0f000;
3652       }
3653     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3654     return This::STATUS_OKAY;
3655   }
3656
3657   // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3658   // R_ARM_ALU_PC_G0:    ((S + A) | T) - P
3659   // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3660   // R_ARM_ALU_PC_G1:    ((S + A) | T) - P
3661   // R_ARM_ALU_PC_G2:    ((S + A) | T) - P
3662   // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3663   // R_ARM_ALU_SB_G0:    ((S + A) | T) - B(S)
3664   // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3665   // R_ARM_ALU_SB_G1:    ((S + A) | T) - B(S)
3666   // R_ARM_ALU_SB_G2:    ((S + A) | T) - B(S)
3667   static inline typename This::Status
3668   arm_grp_alu(unsigned char* view,
3669         const Sized_relobj<32, big_endian>* object,
3670         const Symbol_value<32>* psymval,
3671         const int group,
3672         Arm_address address,
3673         Arm_address thumb_bit,
3674         bool check_overflow)
3675   {
3676     gold_assert(group >= 0 && group < 3);
3677     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3678     Valtype* wv = reinterpret_cast<Valtype*>(view);
3679     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3680
3681     // ALU group relocations are allowed only for the ADD/SUB instructions.
3682     // (0x00800000 - ADD, 0x00400000 - SUB)
3683     const Valtype opcode = insn & 0x01e00000;
3684     if (opcode != 0x00800000 && opcode != 0x00400000)
3685       return This::STATUS_BAD_RELOC;
3686
3687     // Determine a sign for the addend.
3688     const int sign = (opcode == 0x00800000) ? 1 : -1;
3689     // shifter = rotate_imm * 2
3690     const uint32_t shifter = (insn & 0xf00) >> 7;
3691     // Initial addend value.
3692     int32_t addend = insn & 0xff;
3693     // Rotate addend right by shifter.
3694     addend = (addend >> shifter) | (addend << (32 - shifter));
3695     // Apply a sign to the added.
3696     addend *= sign;
3697
3698     int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3699     Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3700     // Check for overflow if required
3701     if (check_overflow
3702         && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3703       return This::STATUS_OVERFLOW;
3704
3705     // Mask out the value and the ADD/SUB part of the opcode; take care
3706     // not to destroy the S bit.
3707     insn &= 0xff1ff000;
3708     // Set the opcode according to whether the value to go in the
3709     // place is negative.
3710     insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3711     // Encode the offset (encoded Gn).
3712     insn |= gn;
3713
3714     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3715     return This::STATUS_OKAY;
3716   }
3717
3718   // R_ARM_LDR_PC_G0: S + A - P
3719   // R_ARM_LDR_PC_G1: S + A - P
3720   // R_ARM_LDR_PC_G2: S + A - P
3721   // R_ARM_LDR_SB_G0: S + A - B(S)
3722   // R_ARM_LDR_SB_G1: S + A - B(S)
3723   // R_ARM_LDR_SB_G2: S + A - B(S)
3724   static inline typename This::Status
3725   arm_grp_ldr(unsigned char* view,
3726         const Sized_relobj<32, big_endian>* object,
3727         const Symbol_value<32>* psymval,
3728         const int group,
3729         Arm_address address)
3730   {
3731     gold_assert(group >= 0 && group < 3);
3732     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3733     Valtype* wv = reinterpret_cast<Valtype*>(view);
3734     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3735
3736     const int sign = (insn & 0x00800000) ? 1 : -1;
3737     int32_t addend = (insn & 0xfff) * sign;
3738     int32_t x = (psymval->value(object, addend) - address);
3739     // Calculate the relevant G(n-1) value to obtain this stage residual.
3740     Valtype residual =
3741         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3742     if (residual >= 0x1000)
3743       return This::STATUS_OVERFLOW;
3744
3745     // Mask out the value and U bit.
3746     insn &= 0xff7ff000;
3747     // Set the U bit for non-negative values.
3748     if (x >= 0)
3749       insn |= 0x00800000;
3750     insn |= residual;
3751
3752     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3753     return This::STATUS_OKAY;
3754   }
3755
3756   // R_ARM_LDRS_PC_G0: S + A - P
3757   // R_ARM_LDRS_PC_G1: S + A - P
3758   // R_ARM_LDRS_PC_G2: S + A - P
3759   // R_ARM_LDRS_SB_G0: S + A - B(S)
3760   // R_ARM_LDRS_SB_G1: S + A - B(S)
3761   // R_ARM_LDRS_SB_G2: S + A - B(S)
3762   static inline typename This::Status
3763   arm_grp_ldrs(unsigned char* view,
3764         const Sized_relobj<32, big_endian>* object,
3765         const Symbol_value<32>* psymval,
3766         const int group,
3767         Arm_address address)
3768   {
3769     gold_assert(group >= 0 && group < 3);
3770     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3771     Valtype* wv = reinterpret_cast<Valtype*>(view);
3772     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3773
3774     const int sign = (insn & 0x00800000) ? 1 : -1;
3775     int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3776     int32_t x = (psymval->value(object, addend) - address);
3777     // Calculate the relevant G(n-1) value to obtain this stage residual.
3778     Valtype residual =
3779         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3780    if (residual >= 0x100)
3781       return This::STATUS_OVERFLOW;
3782
3783     // Mask out the value and U bit.
3784     insn &= 0xff7ff0f0;
3785     // Set the U bit for non-negative values.
3786     if (x >= 0)
3787       insn |= 0x00800000;
3788     insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3789
3790     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3791     return This::STATUS_OKAY;
3792   }
3793
3794   // R_ARM_LDC_PC_G0: S + A - P
3795   // R_ARM_LDC_PC_G1: S + A - P
3796   // R_ARM_LDC_PC_G2: S + A - P
3797   // R_ARM_LDC_SB_G0: S + A - B(S)
3798   // R_ARM_LDC_SB_G1: S + A - B(S)
3799   // R_ARM_LDC_SB_G2: S + A - B(S)
3800   static inline typename This::Status
3801   arm_grp_ldc(unsigned char* view,
3802       const Sized_relobj<32, big_endian>* object,
3803       const Symbol_value<32>* psymval,
3804       const int group,
3805       Arm_address address)
3806   {
3807     gold_assert(group >= 0 && group < 3);
3808     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3809     Valtype* wv = reinterpret_cast<Valtype*>(view);
3810     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3811
3812     const int sign = (insn & 0x00800000) ? 1 : -1;
3813     int32_t addend = ((insn & 0xff) << 2) * sign;
3814     int32_t x = (psymval->value(object, addend) - address);
3815     // Calculate the relevant G(n-1) value to obtain this stage residual.
3816     Valtype residual =
3817       Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3818     if ((residual & 0x3) != 0 || residual >= 0x400)
3819       return This::STATUS_OVERFLOW;
3820
3821     // Mask out the value and U bit.
3822     insn &= 0xff7fff00;
3823     // Set the U bit for non-negative values.
3824     if (x >= 0)
3825       insn |= 0x00800000;
3826     insn |= (residual >> 2);
3827
3828     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3829     return This::STATUS_OKAY;
3830   }
3831 };
3832
3833 // Relocate ARM long branches.  This handles relocation types
3834 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3835 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3836 // undefined and we do not use PLT in this relocation.  In such a case,
3837 // the branch is converted into an NOP.
3838
3839 template<bool big_endian>
3840 typename Arm_relocate_functions<big_endian>::Status
3841 Arm_relocate_functions<big_endian>::arm_branch_common(
3842     unsigned int r_type,
3843     const Relocate_info<32, big_endian>* relinfo,
3844     unsigned char* view,
3845     const Sized_symbol<32>* gsym,
3846     const Arm_relobj<big_endian>* object,
3847     unsigned int r_sym,
3848     const Symbol_value<32>* psymval,
3849     Arm_address address,
3850     Arm_address thumb_bit,
3851     bool is_weakly_undefined_without_plt)
3852 {
3853   typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3854   Valtype* wv = reinterpret_cast<Valtype*>(view);
3855   Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3856      
3857   bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3858                     && ((val & 0x0f000000UL) == 0x0a000000UL);
3859   bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3860   bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3861                           && ((val & 0x0f000000UL) == 0x0b000000UL);
3862   bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3863   bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3864
3865   // Check that the instruction is valid.
3866   if (r_type == elfcpp::R_ARM_CALL)
3867     {
3868       if (!insn_is_uncond_bl && !insn_is_blx)
3869         return This::STATUS_BAD_RELOC;
3870     }
3871   else if (r_type == elfcpp::R_ARM_JUMP24)
3872     {
3873       if (!insn_is_b && !insn_is_cond_bl)
3874         return This::STATUS_BAD_RELOC;
3875     }
3876   else if (r_type == elfcpp::R_ARM_PLT32)
3877     {
3878       if (!insn_is_any_branch)
3879         return This::STATUS_BAD_RELOC;
3880     }
3881   else if (r_type == elfcpp::R_ARM_XPC25)
3882     {
3883       // FIXME: AAELF document IH0044C does not say much about it other
3884       // than it being obsolete.
3885       if (!insn_is_any_branch)
3886         return This::STATUS_BAD_RELOC;
3887     }
3888   else
3889     gold_unreachable();
3890
3891   // A branch to an undefined weak symbol is turned into a jump to
3892   // the next instruction unless a PLT entry will be created.
3893   // Do the same for local undefined symbols.
3894   // The jump to the next instruction is optimized as a NOP depending
3895   // on the architecture.
3896   const Target_arm<big_endian>* arm_target =
3897     Target_arm<big_endian>::default_target();
3898   if (is_weakly_undefined_without_plt)
3899     {
3900       gold_assert(!parameters->options().relocatable());
3901       Valtype cond = val & 0xf0000000U;
3902       if (arm_target->may_use_arm_nop())
3903         val = cond | 0x0320f000;
3904       else
3905         val = cond | 0x01a00000;        // Using pre-UAL nop: mov r0, r0.
3906       elfcpp::Swap<32, big_endian>::writeval(wv, val);
3907       return This::STATUS_OKAY;
3908     }
3909  
3910   Valtype addend = utils::sign_extend<26>(val << 2);
3911   Valtype branch_target = psymval->value(object, addend);
3912   int32_t branch_offset = branch_target - address;
3913
3914   // We need a stub if the branch offset is too large or if we need
3915   // to switch mode.
3916   bool may_use_blx = arm_target->may_use_blx();
3917   Reloc_stub* stub = NULL;
3918
3919   if (!parameters->options().relocatable()
3920       && (utils::has_overflow<26>(branch_offset)
3921           || ((thumb_bit != 0)
3922               && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3923     {
3924       Valtype unadjusted_branch_target = psymval->value(object, 0);
3925
3926       Stub_type stub_type =
3927         Reloc_stub::stub_type_for_reloc(r_type, address,
3928                                         unadjusted_branch_target,
3929                                         (thumb_bit != 0));
3930       if (stub_type != arm_stub_none)
3931         {
3932           Stub_table<big_endian>* stub_table =
3933             object->stub_table(relinfo->data_shndx);
3934           gold_assert(stub_table != NULL);
3935
3936           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3937           stub = stub_table->find_reloc_stub(stub_key);
3938           gold_assert(stub != NULL);
3939           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3940           branch_target = stub_table->address() + stub->offset() + addend;
3941           branch_offset = branch_target - address;
3942           gold_assert(!utils::has_overflow<26>(branch_offset));
3943         }
3944     }
3945
3946   // At this point, if we still need to switch mode, the instruction
3947   // must either be a BLX or a BL that can be converted to a BLX.
3948   if (thumb_bit != 0)
3949     {
3950       // Turn BL to BLX.
3951       gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3952       val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3953     }
3954
3955   val = utils::bit_select(val, (branch_offset >> 2), 0xffffffUL);
3956   elfcpp::Swap<32, big_endian>::writeval(wv, val);
3957   return (utils::has_overflow<26>(branch_offset)
3958           ? This::STATUS_OVERFLOW : This::STATUS_OKAY);
3959 }
3960
3961 // Relocate THUMB long branches.  This handles relocation types
3962 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3963 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3964 // undefined and we do not use PLT in this relocation.  In such a case,
3965 // the branch is converted into an NOP.
3966
3967 template<bool big_endian>
3968 typename Arm_relocate_functions<big_endian>::Status
3969 Arm_relocate_functions<big_endian>::thumb_branch_common(
3970     unsigned int r_type,
3971     const Relocate_info<32, big_endian>* relinfo,
3972     unsigned char* view,
3973     const Sized_symbol<32>* gsym,
3974     const Arm_relobj<big_endian>* object,
3975     unsigned int r_sym,
3976     const Symbol_value<32>* psymval,
3977     Arm_address address,
3978     Arm_address thumb_bit,
3979     bool is_weakly_undefined_without_plt)
3980 {
3981   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3982   Valtype* wv = reinterpret_cast<Valtype*>(view);
3983   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
3984   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
3985
3986   // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
3987   // into account.
3988   bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
3989   bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
3990      
3991   // Check that the instruction is valid.
3992   if (r_type == elfcpp::R_ARM_THM_CALL)
3993     {
3994       if (!is_bl_insn && !is_blx_insn)
3995         return This::STATUS_BAD_RELOC;
3996     }
3997   else if (r_type == elfcpp::R_ARM_THM_JUMP24)
3998     {
3999       // This cannot be a BLX.
4000       if (!is_bl_insn)
4001         return This::STATUS_BAD_RELOC;
4002     }
4003   else if (r_type == elfcpp::R_ARM_THM_XPC22)
4004     {
4005       // Check for Thumb to Thumb call.
4006       if (!is_blx_insn)
4007         return This::STATUS_BAD_RELOC;
4008       if (thumb_bit != 0)
4009         {
4010           gold_warning(_("%s: Thumb BLX instruction targets "
4011                          "thumb function '%s'."),
4012                          object->name().c_str(),
4013                          (gsym ? gsym->name() : "(local)")); 
4014           // Convert BLX to BL.
4015           lower_insn |= 0x1000U;
4016         }
4017     }
4018   else
4019     gold_unreachable();
4020
4021   // A branch to an undefined weak symbol is turned into a jump to
4022   // the next instruction unless a PLT entry will be created.
4023   // The jump to the next instruction is optimized as a NOP.W for
4024   // Thumb-2 enabled architectures.
4025   const Target_arm<big_endian>* arm_target =
4026     Target_arm<big_endian>::default_target();
4027   if (is_weakly_undefined_without_plt)
4028     {
4029       gold_assert(!parameters->options().relocatable());
4030       if (arm_target->may_use_thumb2_nop())
4031         {
4032           elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4033           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4034         }
4035       else
4036         {
4037           elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4038           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4039         }
4040       return This::STATUS_OKAY;
4041     }
4042  
4043   int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4044   Arm_address branch_target = psymval->value(object, addend);
4045
4046   // For BLX, bit 1 of target address comes from bit 1 of base address.
4047   bool may_use_blx = arm_target->may_use_blx();
4048   if (thumb_bit == 0 && may_use_blx)
4049     branch_target = utils::bit_select(branch_target, address, 0x2);
4050
4051   int32_t branch_offset = branch_target - address;
4052
4053   // We need a stub if the branch offset is too large or if we need
4054   // to switch mode.
4055   bool thumb2 = arm_target->using_thumb2();
4056   if (!parameters->options().relocatable()
4057       && ((!thumb2 && utils::has_overflow<23>(branch_offset))
4058           || (thumb2 && utils::has_overflow<25>(branch_offset))
4059           || ((thumb_bit == 0)
4060               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4061                   || r_type == elfcpp::R_ARM_THM_JUMP24))))
4062     {
4063       Arm_address unadjusted_branch_target = psymval->value(object, 0);
4064
4065       Stub_type stub_type =
4066         Reloc_stub::stub_type_for_reloc(r_type, address,
4067                                         unadjusted_branch_target,
4068                                         (thumb_bit != 0));
4069
4070       if (stub_type != arm_stub_none)
4071         {
4072           Stub_table<big_endian>* stub_table =
4073             object->stub_table(relinfo->data_shndx);
4074           gold_assert(stub_table != NULL);
4075
4076           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4077           Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4078           gold_assert(stub != NULL);
4079           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4080           branch_target = stub_table->address() + stub->offset() + addend;
4081           if (thumb_bit == 0 && may_use_blx) 
4082             branch_target = utils::bit_select(branch_target, address, 0x2);
4083           branch_offset = branch_target - address;
4084         }
4085     }
4086
4087   // At this point, if we still need to switch mode, the instruction
4088   // must either be a BLX or a BL that can be converted to a BLX.
4089   if (thumb_bit == 0)
4090     {
4091       gold_assert(may_use_blx
4092                   && (r_type == elfcpp::R_ARM_THM_CALL
4093                       || r_type == elfcpp::R_ARM_THM_XPC22));
4094       // Make sure this is a BLX.
4095       lower_insn &= ~0x1000U;
4096     }
4097   else
4098     {
4099       // Make sure this is a BL.
4100       lower_insn |= 0x1000U;
4101     }
4102
4103   // For a BLX instruction, make sure that the relocation is rounded up
4104   // to a word boundary.  This follows the semantics of the instruction
4105   // which specifies that bit 1 of the target address will come from bit
4106   // 1 of the base address.
4107   if ((lower_insn & 0x5000U) == 0x4000U)
4108     gold_assert((branch_offset & 3) == 0);
4109
4110   // Put BRANCH_OFFSET back into the insn.  Assumes two's complement.
4111   // We use the Thumb-2 encoding, which is safe even if dealing with
4112   // a Thumb-1 instruction by virtue of our overflow check above.  */
4113   upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4114   lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4115
4116   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4117   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4118
4119   gold_assert(!utils::has_overflow<25>(branch_offset));
4120
4121   return ((thumb2
4122            ? utils::has_overflow<25>(branch_offset)
4123            : utils::has_overflow<23>(branch_offset))
4124           ? This::STATUS_OVERFLOW
4125           : This::STATUS_OKAY);
4126 }
4127
4128 // Relocate THUMB-2 long conditional branches.
4129 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
4130 // undefined and we do not use PLT in this relocation.  In such a case,
4131 // the branch is converted into an NOP.
4132
4133 template<bool big_endian>
4134 typename Arm_relocate_functions<big_endian>::Status
4135 Arm_relocate_functions<big_endian>::thm_jump19(
4136     unsigned char* view,
4137     const Arm_relobj<big_endian>* object,
4138     const Symbol_value<32>* psymval,
4139     Arm_address address,
4140     Arm_address thumb_bit)
4141 {
4142   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4143   Valtype* wv = reinterpret_cast<Valtype*>(view);
4144   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4145   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4146   int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4147
4148   Arm_address branch_target = psymval->value(object, addend);
4149   int32_t branch_offset = branch_target - address;
4150
4151   // ??? Should handle interworking?  GCC might someday try to
4152   // use this for tail calls.
4153   // FIXME: We do support thumb entry to PLT yet.
4154   if (thumb_bit == 0)
4155     {
4156       gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4157       return This::STATUS_BAD_RELOC;
4158     }
4159
4160   // Put RELOCATION back into the insn.
4161   upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4162   lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4163
4164   // Put the relocated value back in the object file:
4165   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4166   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4167
4168   return (utils::has_overflow<21>(branch_offset)
4169           ? This::STATUS_OVERFLOW
4170           : This::STATUS_OKAY);
4171 }
4172
4173 // Get the GOT section, creating it if necessary.
4174
4175 template<bool big_endian>
4176 Arm_output_data_got<big_endian>*
4177 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4178 {
4179   if (this->got_ == NULL)
4180     {
4181       gold_assert(symtab != NULL && layout != NULL);
4182
4183       this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4184
4185       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4186                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4187                                       this->got_, ORDER_DATA, false);
4188
4189       // The old GNU linker creates a .got.plt section.  We just
4190       // create another set of data in the .got section.  Note that we
4191       // always create a PLT if we create a GOT, although the PLT
4192       // might be empty.
4193       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4194       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4195                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4196                                       this->got_plt_, ORDER_DATA, false);
4197
4198       // The first three entries are reserved.
4199       this->got_plt_->set_current_data_size(3 * 4);
4200
4201       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4202       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4203                                     Symbol_table::PREDEFINED,
4204                                     this->got_plt_,
4205                                     0, 0, elfcpp::STT_OBJECT,
4206                                     elfcpp::STB_LOCAL,
4207                                     elfcpp::STV_HIDDEN, 0,
4208                                     false, false);
4209     }
4210   return this->got_;
4211 }
4212
4213 // Get the dynamic reloc section, creating it if necessary.
4214
4215 template<bool big_endian>
4216 typename Target_arm<big_endian>::Reloc_section*
4217 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4218 {
4219   if (this->rel_dyn_ == NULL)
4220     {
4221       gold_assert(layout != NULL);
4222       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4223       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4224                                       elfcpp::SHF_ALLOC, this->rel_dyn_,
4225                                       ORDER_DYNAMIC_RELOCS, false);
4226     }
4227   return this->rel_dyn_;
4228 }
4229
4230 // Insn_template methods.
4231
4232 // Return byte size of an instruction template.
4233
4234 size_t
4235 Insn_template::size() const
4236 {
4237   switch (this->type())
4238     {
4239     case THUMB16_TYPE:
4240     case THUMB16_SPECIAL_TYPE:
4241       return 2;
4242     case ARM_TYPE:
4243     case THUMB32_TYPE:
4244     case DATA_TYPE:
4245       return 4;
4246     default:
4247       gold_unreachable();
4248     }
4249 }
4250
4251 // Return alignment of an instruction template.
4252
4253 unsigned
4254 Insn_template::alignment() const
4255 {
4256   switch (this->type())
4257     {
4258     case THUMB16_TYPE:
4259     case THUMB16_SPECIAL_TYPE:
4260     case THUMB32_TYPE:
4261       return 2;
4262     case ARM_TYPE:
4263     case DATA_TYPE:
4264       return 4;
4265     default:
4266       gold_unreachable();
4267     }
4268 }
4269
4270 // Stub_template methods.
4271
4272 Stub_template::Stub_template(
4273     Stub_type type, const Insn_template* insns,
4274      size_t insn_count)
4275   : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4276     entry_in_thumb_mode_(false), relocs_()
4277 {
4278   off_t offset = 0;
4279
4280   // Compute byte size and alignment of stub template.
4281   for (size_t i = 0; i < insn_count; i++)
4282     {
4283       unsigned insn_alignment = insns[i].alignment();
4284       size_t insn_size = insns[i].size();
4285       gold_assert((offset & (insn_alignment - 1)) == 0);
4286       this->alignment_ = std::max(this->alignment_, insn_alignment);
4287       switch (insns[i].type())
4288         {
4289         case Insn_template::THUMB16_TYPE:
4290         case Insn_template::THUMB16_SPECIAL_TYPE:
4291           if (i == 0)
4292             this->entry_in_thumb_mode_ = true;
4293           break;
4294
4295         case Insn_template::THUMB32_TYPE:
4296           if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4297             this->relocs_.push_back(Reloc(i, offset));
4298           if (i == 0)
4299             this->entry_in_thumb_mode_ = true;
4300           break;
4301
4302         case Insn_template::ARM_TYPE:
4303           // Handle cases where the target is encoded within the
4304           // instruction.
4305           if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4306             this->relocs_.push_back(Reloc(i, offset));
4307           break;
4308
4309         case Insn_template::DATA_TYPE:
4310           // Entry point cannot be data.
4311           gold_assert(i != 0);
4312           this->relocs_.push_back(Reloc(i, offset));
4313           break;
4314
4315         default:
4316           gold_unreachable();
4317         }
4318       offset += insn_size; 
4319     }
4320   this->size_ = offset;
4321 }
4322
4323 // Stub methods.
4324
4325 // Template to implement do_write for a specific target endianness.
4326
4327 template<bool big_endian>
4328 void inline
4329 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4330 {
4331   const Stub_template* stub_template = this->stub_template();
4332   const Insn_template* insns = stub_template->insns();
4333
4334   // FIXME:  We do not handle BE8 encoding yet.
4335   unsigned char* pov = view;
4336   for (size_t i = 0; i < stub_template->insn_count(); i++)
4337     {
4338       switch (insns[i].type())
4339         {
4340         case Insn_template::THUMB16_TYPE:
4341           elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4342           break;
4343         case Insn_template::THUMB16_SPECIAL_TYPE:
4344           elfcpp::Swap<16, big_endian>::writeval(
4345               pov,
4346               this->thumb16_special(i));
4347           break;
4348         case Insn_template::THUMB32_TYPE:
4349           {
4350             uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4351             uint32_t lo = insns[i].data() & 0xffff;
4352             elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4353             elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4354           }
4355           break;
4356         case Insn_template::ARM_TYPE:
4357         case Insn_template::DATA_TYPE:
4358           elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4359           break;
4360         default:
4361           gold_unreachable();
4362         }
4363       pov += insns[i].size();
4364     }
4365   gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4366
4367
4368 // Reloc_stub::Key methods.
4369
4370 // Dump a Key as a string for debugging.
4371
4372 std::string
4373 Reloc_stub::Key::name() const
4374 {
4375   if (this->r_sym_ == invalid_index)
4376     {
4377       // Global symbol key name
4378       // <stub-type>:<symbol name>:<addend>.
4379       const std::string sym_name = this->u_.symbol->name();
4380       // We need to print two hex number and two colons.  So just add 100 bytes
4381       // to the symbol name size.
4382       size_t len = sym_name.size() + 100;
4383       char* buffer = new char[len];
4384       int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4385                        sym_name.c_str(), this->addend_);
4386       gold_assert(c > 0 && c < static_cast<int>(len));
4387       delete[] buffer;
4388       return std::string(buffer);
4389     }
4390   else
4391     {
4392       // local symbol key name
4393       // <stub-type>:<object>:<r_sym>:<addend>.
4394       const size_t len = 200;
4395       char buffer[len];
4396       int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4397                        this->u_.relobj, this->r_sym_, this->addend_);
4398       gold_assert(c > 0 && c < static_cast<int>(len));
4399       return std::string(buffer);
4400     }
4401 }
4402
4403 // Reloc_stub methods.
4404
4405 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4406 // LOCATION to DESTINATION.
4407 // This code is based on the arm_type_of_stub function in
4408 // bfd/elf32-arm.c.  We have changed the interface a liitle to keep the Stub
4409 // class simple.
4410
4411 Stub_type
4412 Reloc_stub::stub_type_for_reloc(
4413    unsigned int r_type,
4414    Arm_address location,
4415    Arm_address destination,
4416    bool target_is_thumb)
4417 {
4418   Stub_type stub_type = arm_stub_none;
4419
4420   // This is a bit ugly but we want to avoid using a templated class for
4421   // big and little endianities.
4422   bool may_use_blx;
4423   bool should_force_pic_veneer;
4424   bool thumb2;
4425   bool thumb_only;
4426   if (parameters->target().is_big_endian())
4427     {
4428       const Target_arm<true>* big_endian_target =
4429         Target_arm<true>::default_target();
4430       may_use_blx = big_endian_target->may_use_blx();
4431       should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4432       thumb2 = big_endian_target->using_thumb2();
4433       thumb_only = big_endian_target->using_thumb_only();
4434     }
4435   else
4436     {
4437       const Target_arm<false>* little_endian_target =
4438         Target_arm<false>::default_target();
4439       may_use_blx = little_endian_target->may_use_blx();
4440       should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4441       thumb2 = little_endian_target->using_thumb2();
4442       thumb_only = little_endian_target->using_thumb_only();
4443     }
4444
4445   int64_t branch_offset;
4446   if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4447     {
4448       // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4449       // base address (instruction address + 4).
4450       if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4451         destination = utils::bit_select(destination, location, 0x2);
4452       branch_offset = static_cast<int64_t>(destination) - location;
4453         
4454       // Handle cases where:
4455       // - this call goes too far (different Thumb/Thumb2 max
4456       //   distance)
4457       // - it's a Thumb->Arm call and blx is not available, or it's a
4458       //   Thumb->Arm branch (not bl). A stub is needed in this case.
4459       if ((!thumb2
4460             && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4461                 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4462           || (thumb2
4463               && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4464                   || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4465           || ((!target_is_thumb)
4466               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4467                   || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4468         {
4469           if (target_is_thumb)
4470             {
4471               // Thumb to thumb.
4472               if (!thumb_only)
4473                 {
4474                   stub_type = (parameters->options().shared()
4475                                || should_force_pic_veneer)
4476                     // PIC stubs.
4477                     ? ((may_use_blx
4478                         && (r_type == elfcpp::R_ARM_THM_CALL))
4479                        // V5T and above. Stub starts with ARM code, so
4480                        // we must be able to switch mode before
4481                        // reaching it, which is only possible for 'bl'
4482                        // (ie R_ARM_THM_CALL relocation).
4483                        ? arm_stub_long_branch_any_thumb_pic
4484                        // On V4T, use Thumb code only.
4485                        : arm_stub_long_branch_v4t_thumb_thumb_pic)
4486
4487                     // non-PIC stubs.
4488                     : ((may_use_blx
4489                         && (r_type == elfcpp::R_ARM_THM_CALL))
4490                        ? arm_stub_long_branch_any_any // V5T and above.
4491                        : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4492                 }
4493               else
4494                 {
4495                   stub_type = (parameters->options().shared()
4496                                || should_force_pic_veneer)
4497                     ? arm_stub_long_branch_thumb_only_pic       // PIC stub.
4498                     : arm_stub_long_branch_thumb_only;  // non-PIC stub.
4499                 }
4500             }
4501           else
4502             {
4503               // Thumb to arm.
4504              
4505               // FIXME: We should check that the input section is from an
4506               // object that has interwork enabled.
4507
4508               stub_type = (parameters->options().shared()
4509                            || should_force_pic_veneer)
4510                 // PIC stubs.
4511                 ? ((may_use_blx
4512                     && (r_type == elfcpp::R_ARM_THM_CALL))
4513                    ? arm_stub_long_branch_any_arm_pic   // V5T and above.
4514                    : arm_stub_long_branch_v4t_thumb_arm_pic)    // V4T.
4515
4516                 // non-PIC stubs.
4517                 : ((may_use_blx
4518                     && (r_type == elfcpp::R_ARM_THM_CALL))
4519                    ? arm_stub_long_branch_any_any       // V5T and above.
4520                    : arm_stub_long_branch_v4t_thumb_arm);       // V4T.
4521
4522               // Handle v4t short branches.
4523               if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4524                   && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4525                   && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4526                 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4527             }
4528         }
4529     }
4530   else if (r_type == elfcpp::R_ARM_CALL
4531            || r_type == elfcpp::R_ARM_JUMP24
4532            || r_type == elfcpp::R_ARM_PLT32)
4533     {
4534       branch_offset = static_cast<int64_t>(destination) - location;
4535       if (target_is_thumb)
4536         {
4537           // Arm to thumb.
4538
4539           // FIXME: We should check that the input section is from an
4540           // object that has interwork enabled.
4541
4542           // We have an extra 2-bytes reach because of
4543           // the mode change (bit 24 (H) of BLX encoding).
4544           if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4545               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4546               || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4547               || (r_type == elfcpp::R_ARM_JUMP24)
4548               || (r_type == elfcpp::R_ARM_PLT32))
4549             {
4550               stub_type = (parameters->options().shared()
4551                            || should_force_pic_veneer)
4552                 // PIC stubs.
4553                 ? (may_use_blx
4554                    ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4555                    : arm_stub_long_branch_v4t_arm_thumb_pic)    // V4T stub.
4556
4557                 // non-PIC stubs.
4558                 : (may_use_blx
4559                    ? arm_stub_long_branch_any_any       // V5T and above.
4560                    : arm_stub_long_branch_v4t_arm_thumb);       // V4T.
4561             }
4562         }
4563       else
4564         {
4565           // Arm to arm.
4566           if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4567               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4568             {
4569               stub_type = (parameters->options().shared()
4570                            || should_force_pic_veneer)
4571                 ? arm_stub_long_branch_any_arm_pic      // PIC stubs.
4572                 : arm_stub_long_branch_any_any;         /// non-PIC.
4573             }
4574         }
4575     }
4576
4577   return stub_type;
4578 }
4579
4580 // Cortex_a8_stub methods.
4581
4582 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4583 // I is the position of the instruction template in the stub template.
4584
4585 uint16_t
4586 Cortex_a8_stub::do_thumb16_special(size_t i)
4587 {
4588   // The only use of this is to copy condition code from a conditional
4589   // branch being worked around to the corresponding conditional branch in
4590   // to the stub.
4591   gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4592               && i == 0);
4593   uint16_t data = this->stub_template()->insns()[i].data();
4594   gold_assert((data & 0xff00U) == 0xd000U);
4595   data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4596   return data;
4597 }
4598
4599 // Stub_factory methods.
4600
4601 Stub_factory::Stub_factory()
4602 {
4603   // The instruction template sequences are declared as static
4604   // objects and initialized first time the constructor runs.
4605  
4606   // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4607   // to reach the stub if necessary.
4608   static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4609     {
4610       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4611       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4612                                                 // dcd   R_ARM_ABS32(X)
4613     };
4614   
4615   // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4616   // available.
4617   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4618     {
4619       Insn_template::arm_insn(0xe59fc000),      // ldr   ip, [pc, #0]
4620       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4621       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4622                                                 // dcd   R_ARM_ABS32(X)
4623     };
4624   
4625   // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4626   static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4627     {
4628       Insn_template::thumb16_insn(0xb401),      // push {r0}
4629       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4630       Insn_template::thumb16_insn(0x4684),      // mov  ip, r0
4631       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4632       Insn_template::thumb16_insn(0x4760),      // bx   ip
4633       Insn_template::thumb16_insn(0xbf00),      // nop
4634       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4635                                                 // dcd  R_ARM_ABS32(X)
4636     };
4637   
4638   // V4T Thumb -> Thumb long branch stub. Using the stack is not
4639   // allowed.
4640   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4641     {
4642       Insn_template::thumb16_insn(0x4778),      // bx   pc
4643       Insn_template::thumb16_insn(0x46c0),      // nop
4644       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4645       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4646       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4647                                                 // dcd  R_ARM_ABS32(X)
4648     };
4649   
4650   // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4651   // available.
4652   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4653     {
4654       Insn_template::thumb16_insn(0x4778),      // bx   pc
4655       Insn_template::thumb16_insn(0x46c0),      // nop
4656       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4657       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4658                                                 // dcd   R_ARM_ABS32(X)
4659     };
4660   
4661   // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4662   // one, when the destination is close enough.
4663   static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4664     {
4665       Insn_template::thumb16_insn(0x4778),              // bx   pc
4666       Insn_template::thumb16_insn(0x46c0),              // nop
4667       Insn_template::arm_rel_insn(0xea000000, -8),      // b    (X-8)
4668     };
4669   
4670   // ARM/Thumb -> ARM long branch stub, PIC.  On V5T and above, use
4671   // blx to reach the stub if necessary.
4672   static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4673     {
4674       Insn_template::arm_insn(0xe59fc000),      // ldr   r12, [pc]
4675       Insn_template::arm_insn(0xe08ff00c),      // add   pc, pc, ip
4676       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4677                                                 // dcd   R_ARM_REL32(X-4)
4678     };
4679   
4680   // ARM/Thumb -> Thumb long branch stub, PIC.  On V5T and above, use
4681   // blx to reach the stub if necessary.  We can not add into pc;
4682   // it is not guaranteed to mode switch (different in ARMv6 and
4683   // ARMv7).
4684   static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4685     {
4686       Insn_template::arm_insn(0xe59fc004),      // ldr   r12, [pc, #4]
4687       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4688       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4689       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4690                                                 // dcd   R_ARM_REL32(X)
4691     };
4692   
4693   // V4T ARM -> ARM long branch stub, PIC.
4694   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4695     {
4696       Insn_template::arm_insn(0xe59fc004),      // ldr   ip, [pc, #4]
4697       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4698       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4699       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4700                                                 // dcd   R_ARM_REL32(X)
4701     };
4702   
4703   // V4T Thumb -> ARM long branch stub, PIC.
4704   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4705     {
4706       Insn_template::thumb16_insn(0x4778),      // bx   pc
4707       Insn_template::thumb16_insn(0x46c0),      // nop
4708       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4709       Insn_template::arm_insn(0xe08cf00f),      // add  pc, ip, pc
4710       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4711                                                 // dcd  R_ARM_REL32(X)
4712     };
4713   
4714   // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4715   // architectures.
4716   static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4717     {
4718       Insn_template::thumb16_insn(0xb401),      // push {r0}
4719       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4720       Insn_template::thumb16_insn(0x46fc),      // mov  ip, pc
4721       Insn_template::thumb16_insn(0x4484),      // add  ip, r0
4722       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4723       Insn_template::thumb16_insn(0x4760),      // bx   ip
4724       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4725                                                 // dcd  R_ARM_REL32(X)
4726     };
4727   
4728   // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4729   // allowed.
4730   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4731     {
4732       Insn_template::thumb16_insn(0x4778),      // bx   pc
4733       Insn_template::thumb16_insn(0x46c0),      // nop
4734       Insn_template::arm_insn(0xe59fc004),      // ldr  ip, [pc, #4]
4735       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4736       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4737       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4738                                                 // dcd  R_ARM_REL32(X)
4739     };
4740   
4741   // Cortex-A8 erratum-workaround stubs.
4742   
4743   // Stub used for conditional branches (which may be beyond +/-1MB away,
4744   // so we can't use a conditional branch to reach this stub).
4745   
4746   // original code:
4747   //
4748   //    b<cond> X
4749   // after:
4750   //
4751   static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4752     {
4753       Insn_template::thumb16_bcond_insn(0xd001),        //      b<cond>.n true
4754       Insn_template::thumb32_b_insn(0xf000b800, -4),    //      b.w after
4755       Insn_template::thumb32_b_insn(0xf000b800, -4)     // true:
4756                                                         //      b.w X
4757     };
4758   
4759   // Stub used for b.w and bl.w instructions.
4760   
4761   static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4762     {
4763       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4764     };
4765   
4766   static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4767     {
4768       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4769     };
4770   
4771   // Stub used for Thumb-2 blx.w instructions.  We modified the original blx.w
4772   // instruction (which switches to ARM mode) to point to this stub.  Jump to
4773   // the real destination using an ARM-mode branch.
4774   static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4775     {
4776       Insn_template::arm_rel_insn(0xea000000, -8)       // b dest
4777     };
4778
4779   // Stub used to provide an interworking for R_ARM_V4BX relocation
4780   // (bx r[n] instruction).
4781   static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4782     {
4783       Insn_template::arm_insn(0xe3100001),              // tst   r<n>, #1
4784       Insn_template::arm_insn(0x01a0f000),              // moveq pc, r<n>
4785       Insn_template::arm_insn(0xe12fff10)               // bx    r<n>
4786     };
4787
4788   // Fill in the stub template look-up table.  Stub templates are constructed
4789   // per instance of Stub_factory for fast look-up without locking
4790   // in a thread-enabled environment.
4791
4792   this->stub_templates_[arm_stub_none] =
4793     new Stub_template(arm_stub_none, NULL, 0);
4794
4795 #define DEF_STUB(x)     \
4796   do \
4797     { \
4798       size_t array_size \
4799         = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4800       Stub_type type = arm_stub_##x; \
4801       this->stub_templates_[type] = \
4802         new Stub_template(type, elf32_arm_stub_##x, array_size); \
4803     } \
4804   while (0);
4805
4806   DEF_STUBS
4807 #undef DEF_STUB
4808 }
4809
4810 // Stub_table methods.
4811
4812 // Removel all Cortex-A8 stub.
4813
4814 template<bool big_endian>
4815 void
4816 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4817 {
4818   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4819        p != this->cortex_a8_stubs_.end();
4820        ++p)
4821     delete p->second;
4822   this->cortex_a8_stubs_.clear();
4823 }
4824
4825 // Relocate one stub.  This is a helper for Stub_table::relocate_stubs().
4826
4827 template<bool big_endian>
4828 void
4829 Stub_table<big_endian>::relocate_stub(
4830     Stub* stub,
4831     const Relocate_info<32, big_endian>* relinfo,
4832     Target_arm<big_endian>* arm_target,
4833     Output_section* output_section,
4834     unsigned char* view,
4835     Arm_address address,
4836     section_size_type view_size)
4837 {
4838   const Stub_template* stub_template = stub->stub_template();
4839   if (stub_template->reloc_count() != 0)
4840     {
4841       // Adjust view to cover the stub only.
4842       section_size_type offset = stub->offset();
4843       section_size_type stub_size = stub_template->size();
4844       gold_assert(offset + stub_size <= view_size);
4845
4846       arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4847                                 address + offset, stub_size);
4848     }
4849 }
4850
4851 // Relocate all stubs in this stub table.
4852
4853 template<bool big_endian>
4854 void
4855 Stub_table<big_endian>::relocate_stubs(
4856     const Relocate_info<32, big_endian>* relinfo,
4857     Target_arm<big_endian>* arm_target,
4858     Output_section* output_section,
4859     unsigned char* view,
4860     Arm_address address,
4861     section_size_type view_size)
4862 {
4863   // If we are passed a view bigger than the stub table's.  we need to
4864   // adjust the view.
4865   gold_assert(address == this->address()
4866               && (view_size
4867                   == static_cast<section_size_type>(this->data_size())));
4868
4869   // Relocate all relocation stubs.
4870   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4871       p != this->reloc_stubs_.end();
4872       ++p)
4873     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4874                         address, view_size);
4875
4876   // Relocate all Cortex-A8 stubs.
4877   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4878        p != this->cortex_a8_stubs_.end();
4879        ++p)
4880     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4881                         address, view_size);
4882
4883   // Relocate all ARM V4BX stubs.
4884   for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4885        p != this->arm_v4bx_stubs_.end();
4886        ++p)
4887     {
4888       if (*p != NULL)
4889         this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4890                             address, view_size);
4891     }
4892 }
4893
4894 // Write out the stubs to file.
4895
4896 template<bool big_endian>
4897 void
4898 Stub_table<big_endian>::do_write(Output_file* of)
4899 {
4900   off_t offset = this->offset();
4901   const section_size_type oview_size =
4902     convert_to_section_size_type(this->data_size());
4903   unsigned char* const oview = of->get_output_view(offset, oview_size);
4904
4905   // Write relocation stubs.
4906   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4907       p != this->reloc_stubs_.end();
4908       ++p)
4909     {
4910       Reloc_stub* stub = p->second;
4911       Arm_address address = this->address() + stub->offset();
4912       gold_assert(address
4913                   == align_address(address,
4914                                    stub->stub_template()->alignment()));
4915       stub->write(oview + stub->offset(), stub->stub_template()->size(),
4916                   big_endian);
4917     }
4918
4919   // Write Cortex-A8 stubs.
4920   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4921        p != this->cortex_a8_stubs_.end();
4922        ++p)
4923     {
4924       Cortex_a8_stub* stub = p->second;
4925       Arm_address address = this->address() + stub->offset();
4926       gold_assert(address
4927                   == align_address(address,
4928                                    stub->stub_template()->alignment()));
4929       stub->write(oview + stub->offset(), stub->stub_template()->size(),
4930                   big_endian);
4931     }
4932
4933   // Write ARM V4BX relocation stubs.
4934   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4935        p != this->arm_v4bx_stubs_.end();
4936        ++p)
4937     {
4938       if (*p == NULL)
4939         continue;
4940
4941       Arm_address address = this->address() + (*p)->offset();
4942       gold_assert(address
4943                   == align_address(address,
4944                                    (*p)->stub_template()->alignment()));
4945       (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4946                   big_endian);
4947     }
4948
4949   of->write_output_view(this->offset(), oview_size, oview);
4950 }
4951
4952 // Update the data size and address alignment of the stub table at the end
4953 // of a relaxation pass.   Return true if either the data size or the
4954 // alignment changed in this relaxation pass.
4955
4956 template<bool big_endian>
4957 bool
4958 Stub_table<big_endian>::update_data_size_and_addralign()
4959 {
4960   // Go over all stubs in table to compute data size and address alignment.
4961   off_t size = this->reloc_stubs_size_;
4962   unsigned addralign = this->reloc_stubs_addralign_;
4963
4964   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4965        p != this->cortex_a8_stubs_.end();
4966        ++p)
4967     {
4968       const Stub_template* stub_template = p->second->stub_template();
4969       addralign = std::max(addralign, stub_template->alignment());
4970       size = (align_address(size, stub_template->alignment())
4971               + stub_template->size());
4972     }
4973
4974   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4975        p != this->arm_v4bx_stubs_.end();
4976        ++p)
4977     {
4978       if (*p == NULL)
4979         continue;
4980
4981       const Stub_template* stub_template = (*p)->stub_template();
4982       addralign = std::max(addralign, stub_template->alignment());
4983       size = (align_address(size, stub_template->alignment())
4984               + stub_template->size());
4985     }
4986
4987   // Check if either data size or alignment changed in this pass.
4988   // Update prev_data_size_ and prev_addralign_.  These will be used
4989   // as the current data size and address alignment for the next pass.
4990   bool changed = size != this->prev_data_size_;
4991   this->prev_data_size_ = size; 
4992
4993   if (addralign != this->prev_addralign_)
4994     changed = true;
4995   this->prev_addralign_ = addralign;
4996
4997   return changed;
4998 }
4999
5000 // Finalize the stubs.  This sets the offsets of the stubs within the stub
5001 // table.  It also marks all input sections needing Cortex-A8 workaround.
5002
5003 template<bool big_endian>
5004 void
5005 Stub_table<big_endian>::finalize_stubs()
5006 {
5007   off_t off = this->reloc_stubs_size_;
5008   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5009        p != this->cortex_a8_stubs_.end();
5010        ++p)
5011     {
5012       Cortex_a8_stub* stub = p->second;
5013       const Stub_template* stub_template = stub->stub_template();
5014       uint64_t stub_addralign = stub_template->alignment();
5015       off = align_address(off, stub_addralign);
5016       stub->set_offset(off);
5017       off += stub_template->size();
5018
5019       // Mark input section so that we can determine later if a code section
5020       // needs the Cortex-A8 workaround quickly.
5021       Arm_relobj<big_endian>* arm_relobj =
5022         Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5023       arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5024     }
5025
5026   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5027       p != this->arm_v4bx_stubs_.end();
5028       ++p)
5029     {
5030       if (*p == NULL)
5031         continue;
5032
5033       const Stub_template* stub_template = (*p)->stub_template();
5034       uint64_t stub_addralign = stub_template->alignment();
5035       off = align_address(off, stub_addralign);
5036       (*p)->set_offset(off);
5037       off += stub_template->size();
5038     }
5039
5040   gold_assert(off <= this->prev_data_size_);
5041 }
5042
5043 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5044 // and VIEW_ADDRESS + VIEW_SIZE - 1.  VIEW points to the mapped address
5045 // of the address range seen by the linker.
5046
5047 template<bool big_endian>
5048 void
5049 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5050     Target_arm<big_endian>* arm_target,
5051     unsigned char* view,
5052     Arm_address view_address,
5053     section_size_type view_size)
5054 {
5055   // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5056   for (Cortex_a8_stub_list::const_iterator p =
5057          this->cortex_a8_stubs_.lower_bound(view_address);
5058        ((p != this->cortex_a8_stubs_.end())
5059         && (p->first < (view_address + view_size)));
5060        ++p)
5061     {
5062       // We do not store the THUMB bit in the LSB of either the branch address
5063       // or the stub offset.  There is no need to strip the LSB.
5064       Arm_address branch_address = p->first;
5065       const Cortex_a8_stub* stub = p->second;
5066       Arm_address stub_address = this->address() + stub->offset();
5067
5068       // Offset of the branch instruction relative to this view.
5069       section_size_type offset =
5070         convert_to_section_size_type(branch_address - view_address);
5071       gold_assert((offset + 4) <= view_size);
5072
5073       arm_target->apply_cortex_a8_workaround(stub, stub_address,
5074                                              view + offset, branch_address);
5075     }
5076 }
5077
5078 // Arm_input_section methods.
5079
5080 // Initialize an Arm_input_section.
5081
5082 template<bool big_endian>
5083 void
5084 Arm_input_section<big_endian>::init()
5085 {
5086   Relobj* relobj = this->relobj();
5087   unsigned int shndx = this->shndx();
5088
5089   // Cache these to speed up size and alignment queries.  It is too slow
5090   // to call section_addraglin and section_size every time.
5091   this->original_addralign_ =
5092     convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5093   this->original_size_ =
5094     convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5095
5096   // We want to make this look like the original input section after
5097   // output sections are finalized.
5098   Output_section* os = relobj->output_section(shndx);
5099   off_t offset = relobj->output_section_offset(shndx);
5100   gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5101   this->set_address(os->address() + offset);
5102   this->set_file_offset(os->offset() + offset);
5103
5104   this->set_current_data_size(this->original_size_);
5105   this->finalize_data_size();
5106 }
5107
5108 template<bool big_endian>
5109 void
5110 Arm_input_section<big_endian>::do_write(Output_file* of)
5111 {
5112   // We have to write out the original section content.
5113   section_size_type section_size;
5114   const unsigned char* section_contents =
5115     this->relobj()->section_contents(this->shndx(), &section_size, false); 
5116   of->write(this->offset(), section_contents, section_size); 
5117
5118   // If this owns a stub table and it is not empty, write it.
5119   if (this->is_stub_table_owner() && !this->stub_table_->empty())
5120     this->stub_table_->write(of);
5121 }
5122
5123 // Finalize data size.
5124
5125 template<bool big_endian>
5126 void
5127 Arm_input_section<big_endian>::set_final_data_size()
5128 {
5129   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5130
5131   if (this->is_stub_table_owner())
5132     {
5133       this->stub_table_->finalize_data_size();
5134       off = align_address(off, this->stub_table_->addralign());
5135       off += this->stub_table_->data_size();
5136     }
5137   this->set_data_size(off);
5138 }
5139
5140 // Reset address and file offset.
5141
5142 template<bool big_endian>
5143 void
5144 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5145 {
5146   // Size of the original input section contents.
5147   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5148
5149   // If this is a stub table owner, account for the stub table size.
5150   if (this->is_stub_table_owner())
5151     {
5152       Stub_table<big_endian>* stub_table = this->stub_table_;
5153
5154       // Reset the stub table's address and file offset.  The
5155       // current data size for child will be updated after that.
5156       stub_table_->reset_address_and_file_offset();
5157       off = align_address(off, stub_table_->addralign());
5158       off += stub_table->current_data_size();
5159     }
5160
5161   this->set_current_data_size(off);
5162 }
5163
5164 // Arm_exidx_cantunwind methods.
5165
5166 // Write this to Output file OF for a fixed endianness.
5167
5168 template<bool big_endian>
5169 void
5170 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5171 {
5172   off_t offset = this->offset();
5173   const section_size_type oview_size = 8;
5174   unsigned char* const oview = of->get_output_view(offset, oview_size);
5175   
5176   typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5177   Valtype* wv = reinterpret_cast<Valtype*>(oview);
5178
5179   Output_section* os = this->relobj_->output_section(this->shndx_);
5180   gold_assert(os != NULL);
5181
5182   Arm_relobj<big_endian>* arm_relobj =
5183     Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5184   Arm_address output_offset =
5185     arm_relobj->get_output_section_offset(this->shndx_);
5186   Arm_address section_start;
5187   if (output_offset != Arm_relobj<big_endian>::invalid_address)
5188     section_start = os->address() + output_offset;
5189   else
5190     {
5191       // Currently this only happens for a relaxed section.
5192       const Output_relaxed_input_section* poris =
5193         os->find_relaxed_input_section(this->relobj_, this->shndx_);
5194       gold_assert(poris != NULL);
5195       section_start = poris->address();
5196     }
5197
5198   // We always append this to the end of an EXIDX section.
5199   Arm_address output_address =
5200     section_start + this->relobj_->section_size(this->shndx_);
5201
5202   // Write out the entry.  The first word either points to the beginning
5203   // or after the end of a text section.  The second word is the special
5204   // EXIDX_CANTUNWIND value.
5205   uint32_t prel31_offset = output_address - this->address();
5206   if (utils::has_overflow<31>(offset))
5207     gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5208   elfcpp::Swap<32, big_endian>::writeval(wv, prel31_offset & 0x7fffffffU);
5209   elfcpp::Swap<32, big_endian>::writeval(wv + 1, elfcpp::EXIDX_CANTUNWIND);
5210
5211   of->write_output_view(this->offset(), oview_size, oview);
5212 }
5213
5214 // Arm_exidx_merged_section methods.
5215
5216 // Constructor for Arm_exidx_merged_section.
5217 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5218 // SECTION_OFFSET_MAP points to a section offset map describing how
5219 // parts of the input section are mapped to output.  DELETED_BYTES is
5220 // the number of bytes deleted from the EXIDX input section.
5221
5222 Arm_exidx_merged_section::Arm_exidx_merged_section(
5223     const Arm_exidx_input_section& exidx_input_section,
5224     const Arm_exidx_section_offset_map& section_offset_map,
5225     uint32_t deleted_bytes)
5226   : Output_relaxed_input_section(exidx_input_section.relobj(),
5227                                  exidx_input_section.shndx(),
5228                                  exidx_input_section.addralign()),
5229     exidx_input_section_(exidx_input_section),
5230     section_offset_map_(section_offset_map)
5231 {
5232   // Fix size here so that we do not need to implement set_final_data_size.
5233   this->set_data_size(exidx_input_section.size() - deleted_bytes);
5234   this->fix_data_size();
5235 }
5236
5237 // Given an input OBJECT, an input section index SHNDX within that
5238 // object, and an OFFSET relative to the start of that input
5239 // section, return whether or not the corresponding offset within
5240 // the output section is known.  If this function returns true, it
5241 // sets *POUTPUT to the output offset.  The value -1 indicates that
5242 // this input offset is being discarded.
5243
5244 bool
5245 Arm_exidx_merged_section::do_output_offset(
5246     const Relobj* relobj,
5247     unsigned int shndx,
5248     section_offset_type offset,
5249     section_offset_type* poutput) const
5250 {
5251   // We only handle offsets for the original EXIDX input section.
5252   if (relobj != this->exidx_input_section_.relobj()
5253       || shndx != this->exidx_input_section_.shndx())
5254     return false;
5255
5256   section_offset_type section_size =
5257     convert_types<section_offset_type>(this->exidx_input_section_.size());
5258   if (offset < 0 || offset >= section_size)
5259     // Input offset is out of valid range.
5260     *poutput = -1;
5261   else
5262     {
5263       // We need to look up the section offset map to determine the output
5264       // offset.  Find the reference point in map that is first offset
5265       // bigger than or equal to this offset.
5266       Arm_exidx_section_offset_map::const_iterator p =
5267         this->section_offset_map_.lower_bound(offset);
5268
5269       // The section offset maps are build such that this should not happen if
5270       // input offset is in the valid range.
5271       gold_assert(p != this->section_offset_map_.end());
5272
5273       // We need to check if this is dropped.
5274      section_offset_type ref = p->first;
5275      section_offset_type mapped_ref = p->second;
5276
5277       if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5278         // Offset is present in output.
5279         *poutput = mapped_ref + (offset - ref);
5280       else
5281         // Offset is discarded owing to EXIDX entry merging.
5282         *poutput = -1;
5283     }
5284   
5285   return true;
5286 }
5287
5288 // Write this to output file OF.
5289
5290 void
5291 Arm_exidx_merged_section::do_write(Output_file* of)
5292 {
5293   // If we retain or discard the whole EXIDX input section,  we would
5294   // not be here.
5295   gold_assert(this->data_size() != this->exidx_input_section_.size()
5296               && this->data_size() != 0);
5297
5298   off_t offset = this->offset();
5299   const section_size_type oview_size = this->data_size();
5300   unsigned char* const oview = of->get_output_view(offset, oview_size);
5301   
5302   Output_section* os = this->relobj()->output_section(this->shndx());
5303   gold_assert(os != NULL);
5304
5305   // Get contents of EXIDX input section.
5306   section_size_type section_size;
5307   const unsigned char* section_contents =
5308     this->relobj()->section_contents(this->shndx(), &section_size, false); 
5309   gold_assert(section_size == this->exidx_input_section_.size());
5310
5311   // Go over spans of input offsets and write only those that are not
5312   // discarded.
5313   section_offset_type in_start = 0;
5314   section_offset_type out_start = 0;
5315   for(Arm_exidx_section_offset_map::const_iterator p =
5316         this->section_offset_map_.begin();
5317       p != this->section_offset_map_.end();
5318       ++p)
5319     {
5320       section_offset_type in_end = p->first;
5321       gold_assert(in_end >= in_start);
5322       section_offset_type out_end = p->second;
5323       size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5324       if (out_end != -1)
5325         {
5326           size_t out_chunk_size =
5327             convert_types<size_t>(out_end - out_start + 1);
5328           gold_assert(out_chunk_size == in_chunk_size);
5329           memcpy(oview + out_start, section_contents + in_start,
5330                  out_chunk_size);
5331           out_start += out_chunk_size;
5332         }
5333       in_start += in_chunk_size;
5334     }
5335
5336   gold_assert(convert_to_section_size_type(out_start) == oview_size);
5337   of->write_output_view(this->offset(), oview_size, oview);
5338 }
5339
5340 // Arm_exidx_fixup methods.
5341
5342 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5343 // is not an EXIDX_CANTUNWIND entry already.  The new EXIDX_CANTUNWIND entry
5344 // points to the end of the last seen EXIDX section.
5345
5346 void
5347 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5348 {
5349   if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5350       && this->last_input_section_ != NULL)
5351     {
5352       Relobj* relobj = this->last_input_section_->relobj();
5353       unsigned int text_shndx = this->last_input_section_->link();
5354       Arm_exidx_cantunwind* cantunwind =
5355         new Arm_exidx_cantunwind(relobj, text_shndx);
5356       this->exidx_output_section_->add_output_section_data(cantunwind);
5357       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5358     }
5359 }
5360
5361 // Process an EXIDX section entry in input.  Return whether this entry
5362 // can be deleted in the output.  SECOND_WORD in the second word of the
5363 // EXIDX entry.
5364
5365 bool
5366 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5367 {
5368   bool delete_entry;
5369   if (second_word == elfcpp::EXIDX_CANTUNWIND)
5370     {
5371       // Merge if previous entry is also an EXIDX_CANTUNWIND.
5372       delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5373       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5374     }
5375   else if ((second_word & 0x80000000) != 0)
5376     {
5377       // Inlined unwinding data.  Merge if equal to previous.
5378       delete_entry = (merge_exidx_entries_
5379                       && this->last_unwind_type_ == UT_INLINED_ENTRY
5380                       && this->last_inlined_entry_ == second_word);
5381       this->last_unwind_type_ = UT_INLINED_ENTRY;
5382       this->last_inlined_entry_ = second_word;
5383     }
5384   else
5385     {
5386       // Normal table entry.  In theory we could merge these too,
5387       // but duplicate entries are likely to be much less common.
5388       delete_entry = false;
5389       this->last_unwind_type_ = UT_NORMAL_ENTRY;
5390     }
5391   return delete_entry;
5392 }
5393
5394 // Update the current section offset map during EXIDX section fix-up.
5395 // If there is no map, create one.  INPUT_OFFSET is the offset of a
5396 // reference point, DELETED_BYTES is the number of deleted by in the
5397 // section so far.  If DELETE_ENTRY is true, the reference point and
5398 // all offsets after the previous reference point are discarded.
5399
5400 void
5401 Arm_exidx_fixup::update_offset_map(
5402     section_offset_type input_offset,
5403     section_size_type deleted_bytes,
5404     bool delete_entry)
5405 {
5406   if (this->section_offset_map_ == NULL)
5407     this->section_offset_map_ = new Arm_exidx_section_offset_map();
5408   section_offset_type output_offset;
5409   if (delete_entry)
5410     output_offset = Arm_exidx_input_section::invalid_offset;
5411   else
5412     output_offset = input_offset - deleted_bytes;
5413   (*this->section_offset_map_)[input_offset] = output_offset;
5414 }
5415
5416 // Process EXIDX_INPUT_SECTION for EXIDX entry merging.  Return the number of
5417 // bytes deleted.  If some entries are merged, also store a pointer to a newly
5418 // created Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP.  The
5419 // caller owns the map and is responsible for releasing it after use.
5420
5421 template<bool big_endian>
5422 uint32_t
5423 Arm_exidx_fixup::process_exidx_section(
5424     const Arm_exidx_input_section* exidx_input_section,
5425     Arm_exidx_section_offset_map** psection_offset_map)
5426 {
5427   Relobj* relobj = exidx_input_section->relobj();
5428   unsigned shndx = exidx_input_section->shndx();
5429   section_size_type section_size;
5430   const unsigned char* section_contents =
5431     relobj->section_contents(shndx, &section_size, false);
5432
5433   if ((section_size % 8) != 0)
5434     {
5435       // Something is wrong with this section.  Better not touch it.
5436       gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5437                  relobj->name().c_str(), shndx);
5438       this->last_input_section_ = exidx_input_section;
5439       this->last_unwind_type_ = UT_NONE;
5440       return 0;
5441     }
5442   
5443   uint32_t deleted_bytes = 0;
5444   bool prev_delete_entry = false;
5445   gold_assert(this->section_offset_map_ == NULL);
5446
5447   for (section_size_type i = 0; i < section_size; i += 8)
5448     {
5449       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5450       const Valtype* wv =
5451           reinterpret_cast<const Valtype*>(section_contents + i + 4);
5452       uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5453
5454       bool delete_entry = this->process_exidx_entry(second_word);
5455
5456       // Entry deletion causes changes in output offsets.  We use a std::map
5457       // to record these.  And entry (x, y) means input offset x
5458       // is mapped to output offset y.  If y is invalid_offset, then x is
5459       // dropped in the output.  Because of the way std::map::lower_bound
5460       // works, we record the last offset in a region w.r.t to keeping or
5461       // dropping.  If there is no entry (x0, y0) for an input offset x0,
5462       // the output offset y0 of it is determined by the output offset y1 of
5463       // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5464       // in the map.  If y1 is not -1, then y0 = y1 + x0 - x1.  Othewise, y1
5465       // y0 is also -1.
5466       if (delete_entry != prev_delete_entry && i != 0)
5467         this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5468
5469       // Update total deleted bytes for this entry.
5470       if (delete_entry)
5471         deleted_bytes += 8;
5472
5473       prev_delete_entry = delete_entry;
5474     }
5475   
5476   // If section offset map is not NULL, make an entry for the end of
5477   // section.
5478   if (this->section_offset_map_ != NULL)
5479     update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5480
5481   *psection_offset_map = this->section_offset_map_;
5482   this->section_offset_map_ = NULL;
5483   this->last_input_section_ = exidx_input_section;
5484   
5485   // Set the first output text section so that we can link the EXIDX output
5486   // section to it.  Ignore any EXIDX input section that is completely merged.
5487   if (this->first_output_text_section_ == NULL
5488       && deleted_bytes != section_size)
5489     {
5490       unsigned int link = exidx_input_section->link();
5491       Output_section* os = relobj->output_section(link);
5492       gold_assert(os != NULL);
5493       this->first_output_text_section_ = os;
5494     }
5495
5496   return deleted_bytes;
5497 }
5498
5499 // Arm_output_section methods.
5500
5501 // Create a stub group for input sections from BEGIN to END.  OWNER
5502 // points to the input section to be the owner a new stub table.
5503
5504 template<bool big_endian>
5505 void
5506 Arm_output_section<big_endian>::create_stub_group(
5507   Input_section_list::const_iterator begin,
5508   Input_section_list::const_iterator end,
5509   Input_section_list::const_iterator owner,
5510   Target_arm<big_endian>* target,
5511   std::vector<Output_relaxed_input_section*>* new_relaxed_sections)
5512 {
5513   // We use a different kind of relaxed section in an EXIDX section.
5514   // The static casting from Output_relaxed_input_section to
5515   // Arm_input_section is invalid in an EXIDX section.  We are okay
5516   // because we should not be calling this for an EXIDX section. 
5517   gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5518
5519   // Currently we convert ordinary input sections into relaxed sections only
5520   // at this point but we may want to support creating relaxed input section
5521   // very early.  So we check here to see if owner is already a relaxed
5522   // section.
5523   
5524   Arm_input_section<big_endian>* arm_input_section;
5525   if (owner->is_relaxed_input_section())
5526     {
5527       arm_input_section =
5528         Arm_input_section<big_endian>::as_arm_input_section(
5529           owner->relaxed_input_section());
5530     }
5531   else
5532     {
5533       gold_assert(owner->is_input_section());
5534       // Create a new relaxed input section.
5535       arm_input_section =
5536         target->new_arm_input_section(owner->relobj(), owner->shndx());
5537       new_relaxed_sections->push_back(arm_input_section);
5538     }
5539
5540   // Create a stub table.
5541   Stub_table<big_endian>* stub_table =
5542     target->new_stub_table(arm_input_section);
5543
5544   arm_input_section->set_stub_table(stub_table);
5545   
5546   Input_section_list::const_iterator p = begin;
5547   Input_section_list::const_iterator prev_p;
5548
5549   // Look for input sections or relaxed input sections in [begin ... end].
5550   do
5551     {
5552       if (p->is_input_section() || p->is_relaxed_input_section())
5553         {
5554           // The stub table information for input sections live
5555           // in their objects.
5556           Arm_relobj<big_endian>* arm_relobj =
5557             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5558           arm_relobj->set_stub_table(p->shndx(), stub_table);
5559         }
5560       prev_p = p++;
5561     }
5562   while (prev_p != end);
5563 }
5564
5565 // Group input sections for stub generation.  GROUP_SIZE is roughly the limit
5566 // of stub groups.  We grow a stub group by adding input section until the
5567 // size is just below GROUP_SIZE.  The last input section will be converted
5568 // into a stub table.  If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5569 // input section after the stub table, effectively double the group size.
5570 // 
5571 // This is similar to the group_sections() function in elf32-arm.c but is
5572 // implemented differently.
5573
5574 template<bool big_endian>
5575 void
5576 Arm_output_section<big_endian>::group_sections(
5577     section_size_type group_size,
5578     bool stubs_always_after_branch,
5579     Target_arm<big_endian>* target)
5580 {
5581   // We only care about sections containing code.
5582   if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
5583     return;
5584
5585   // States for grouping.
5586   typedef enum
5587   {
5588     // No group is being built.
5589     NO_GROUP,
5590     // A group is being built but the stub table is not found yet.
5591     // We keep group a stub group until the size is just under GROUP_SIZE.
5592     // The last input section in the group will be used as the stub table.
5593     FINDING_STUB_SECTION,
5594     // A group is being built and we have already found a stub table.
5595     // We enter this state to grow a stub group by adding input section
5596     // after the stub table.  This effectively doubles the group size.
5597     HAS_STUB_SECTION
5598   } State;
5599
5600   // Any newly created relaxed sections are stored here.
5601   std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5602
5603   State state = NO_GROUP;
5604   section_size_type off = 0;
5605   section_size_type group_begin_offset = 0;
5606   section_size_type group_end_offset = 0;
5607   section_size_type stub_table_end_offset = 0;
5608   Input_section_list::const_iterator group_begin =
5609     this->input_sections().end();
5610   Input_section_list::const_iterator stub_table =
5611     this->input_sections().end();
5612   Input_section_list::const_iterator group_end = this->input_sections().end();
5613   for (Input_section_list::const_iterator p = this->input_sections().begin();
5614        p != this->input_sections().end();
5615        ++p)
5616     {
5617       section_size_type section_begin_offset =
5618         align_address(off, p->addralign());
5619       section_size_type section_end_offset =
5620         section_begin_offset + p->data_size(); 
5621       
5622       // Check to see if we should group the previously seens sections.
5623       switch (state)
5624         {
5625         case NO_GROUP:
5626           break;
5627
5628         case FINDING_STUB_SECTION:
5629           // Adding this section makes the group larger than GROUP_SIZE.
5630           if (section_end_offset - group_begin_offset >= group_size)
5631             {
5632               if (stubs_always_after_branch)
5633                 {       
5634                   gold_assert(group_end != this->input_sections().end());
5635                   this->create_stub_group(group_begin, group_end, group_end,
5636                                           target, &new_relaxed_sections);
5637                   state = NO_GROUP;
5638                 }
5639               else
5640                 {
5641                   // But wait, there's more!  Input sections up to
5642                   // stub_group_size bytes after the stub table can be
5643                   // handled by it too.
5644                   state = HAS_STUB_SECTION;
5645                   stub_table = group_end;
5646                   stub_table_end_offset = group_end_offset;
5647                 }
5648             }
5649             break;
5650
5651         case HAS_STUB_SECTION:
5652           // Adding this section makes the post stub-section group larger
5653           // than GROUP_SIZE.
5654           if (section_end_offset - stub_table_end_offset >= group_size)
5655            {
5656              gold_assert(group_end != this->input_sections().end());
5657              this->create_stub_group(group_begin, group_end, stub_table,
5658                                      target, &new_relaxed_sections);
5659              state = NO_GROUP;
5660            }
5661            break;
5662
5663           default:
5664             gold_unreachable();
5665         }       
5666
5667       // If we see an input section and currently there is no group, start
5668       // a new one.  Skip any empty sections.
5669       if ((p->is_input_section() || p->is_relaxed_input_section())
5670           && (p->relobj()->section_size(p->shndx()) != 0))
5671         {
5672           if (state == NO_GROUP)
5673             {
5674               state = FINDING_STUB_SECTION;
5675               group_begin = p;
5676               group_begin_offset = section_begin_offset;
5677             }
5678
5679           // Keep track of the last input section seen.
5680           group_end = p;
5681           group_end_offset = section_end_offset;
5682         }
5683
5684       off = section_end_offset;
5685     }
5686
5687   // Create a stub group for any ungrouped sections.
5688   if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5689     {
5690       gold_assert(group_end != this->input_sections().end());
5691       this->create_stub_group(group_begin, group_end,
5692                               (state == FINDING_STUB_SECTION
5693                                ? group_end
5694                                : stub_table),
5695                                target, &new_relaxed_sections);
5696     }
5697
5698   // Convert input section into relaxed input section in a batch.
5699   if (!new_relaxed_sections.empty())
5700     this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5701
5702   // Update the section offsets
5703   for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5704     {
5705       Arm_relobj<big_endian>* arm_relobj =
5706         Arm_relobj<big_endian>::as_arm_relobj(
5707           new_relaxed_sections[i]->relobj());
5708       unsigned int shndx = new_relaxed_sections[i]->shndx();
5709       // Tell Arm_relobj that this input section is converted.
5710       arm_relobj->convert_input_section_to_relaxed_section(shndx);
5711     }
5712 }
5713
5714 // Append non empty text sections in this to LIST in ascending
5715 // order of their position in this.
5716
5717 template<bool big_endian>
5718 void
5719 Arm_output_section<big_endian>::append_text_sections_to_list(
5720     Text_section_list* list)
5721 {
5722   gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5723
5724   for (Input_section_list::const_iterator p = this->input_sections().begin();
5725        p != this->input_sections().end();
5726        ++p)
5727     {
5728       // We only care about plain or relaxed input sections.  We also
5729       // ignore any merged sections.
5730       if ((p->is_input_section() || p->is_relaxed_input_section())
5731           && p->data_size() != 0)
5732         list->push_back(Text_section_list::value_type(p->relobj(),
5733                                                       p->shndx()));
5734     }
5735 }
5736
5737 template<bool big_endian>
5738 void
5739 Arm_output_section<big_endian>::fix_exidx_coverage(
5740     Layout* layout,
5741     const Text_section_list& sorted_text_sections,
5742     Symbol_table* symtab,
5743     bool merge_exidx_entries)
5744 {
5745   // We should only do this for the EXIDX output section.
5746   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5747
5748   // We don't want the relaxation loop to undo these changes, so we discard
5749   // the current saved states and take another one after the fix-up.
5750   this->discard_states();
5751
5752   // Remove all input sections.
5753   uint64_t address = this->address();
5754   typedef std::list<Output_section::Input_section> Input_section_list;
5755   Input_section_list input_sections;
5756   this->reset_address_and_file_offset();
5757   this->get_input_sections(address, std::string(""), &input_sections);
5758
5759   if (!this->input_sections().empty())
5760     gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5761   
5762   // Go through all the known input sections and record them.
5763   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5764   typedef Unordered_map<Section_id, const Output_section::Input_section*,
5765                         Section_id_hash> Text_to_exidx_map;
5766   Text_to_exidx_map text_to_exidx_map;
5767   for (Input_section_list::const_iterator p = input_sections.begin();
5768        p != input_sections.end();
5769        ++p)
5770     {
5771       // This should never happen.  At this point, we should only see
5772       // plain EXIDX input sections.
5773       gold_assert(!p->is_relaxed_input_section());
5774       text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5775     }
5776
5777   Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5778
5779   // Go over the sorted text sections.
5780   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5781   Section_id_set processed_input_sections;
5782   for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5783        p != sorted_text_sections.end();
5784        ++p)
5785     {
5786       Relobj* relobj = p->first;
5787       unsigned int shndx = p->second;
5788
5789       Arm_relobj<big_endian>* arm_relobj =
5790          Arm_relobj<big_endian>::as_arm_relobj(relobj);
5791       const Arm_exidx_input_section* exidx_input_section =
5792          arm_relobj->exidx_input_section_by_link(shndx);
5793
5794       // If this text section has no EXIDX section or if the EXIDX section
5795       // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5796       // of the last seen EXIDX section.
5797       if (exidx_input_section == NULL || exidx_input_section->has_errors())
5798         {
5799           exidx_fixup.add_exidx_cantunwind_as_needed();
5800           continue;
5801         }
5802
5803       Relobj* exidx_relobj = exidx_input_section->relobj();
5804       unsigned int exidx_shndx = exidx_input_section->shndx();
5805       Section_id sid(exidx_relobj, exidx_shndx);
5806       Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5807       if (iter == text_to_exidx_map.end())
5808         {
5809           // This is odd.  We have not seen this EXIDX input section before.
5810           // We cannot do fix-up.  If we saw a SECTIONS clause in a script,
5811           // issue a warning instead.  We assume the user knows what he
5812           // or she is doing.  Otherwise, this is an error.
5813           if (layout->script_options()->saw_sections_clause())
5814             gold_warning(_("unwinding may not work because EXIDX input section"
5815                            " %u of %s is not in EXIDX output section"),
5816                          exidx_shndx, exidx_relobj->name().c_str());
5817           else
5818             gold_error(_("unwinding may not work because EXIDX input section"
5819                          " %u of %s is not in EXIDX output section"),
5820                        exidx_shndx, exidx_relobj->name().c_str());
5821
5822           exidx_fixup.add_exidx_cantunwind_as_needed();
5823           continue;
5824         }
5825
5826       // Fix up coverage and append input section to output data list.
5827       Arm_exidx_section_offset_map* section_offset_map = NULL;
5828       uint32_t deleted_bytes =
5829         exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5830                                                       &section_offset_map);
5831
5832       if (deleted_bytes == exidx_input_section->size())
5833         {
5834           // The whole EXIDX section got merged.  Remove it from output.
5835           gold_assert(section_offset_map == NULL);
5836           exidx_relobj->set_output_section(exidx_shndx, NULL);
5837
5838           // All local symbols defined in this input section will be dropped.
5839           // We need to adjust output local symbol count.
5840           arm_relobj->set_output_local_symbol_count_needs_update();
5841         }
5842       else if (deleted_bytes > 0)
5843         {
5844           // Some entries are merged.  We need to convert this EXIDX input
5845           // section into a relaxed section.
5846           gold_assert(section_offset_map != NULL);
5847           Arm_exidx_merged_section* merged_section =
5848             new Arm_exidx_merged_section(*exidx_input_section,
5849                                          *section_offset_map, deleted_bytes);
5850           this->add_relaxed_input_section(merged_section);
5851           arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5852
5853           // All local symbols defined in discarded portions of this input
5854           // section will be dropped.  We need to adjust output local symbol
5855           // count.
5856           arm_relobj->set_output_local_symbol_count_needs_update();
5857         }
5858       else
5859         {
5860           // Just add back the EXIDX input section.
5861           gold_assert(section_offset_map == NULL);
5862           const Output_section::Input_section* pis = iter->second;
5863           gold_assert(pis->is_input_section());
5864           this->add_script_input_section(*pis);
5865         }
5866
5867       processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx)); 
5868     }
5869
5870   // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5871   exidx_fixup.add_exidx_cantunwind_as_needed();
5872
5873   // Remove any known EXIDX input sections that are not processed.
5874   for (Input_section_list::const_iterator p = input_sections.begin();
5875        p != input_sections.end();
5876        ++p)
5877     {
5878       if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5879           == processed_input_sections.end())
5880         {
5881           // We discard a known EXIDX section because its linked
5882           // text section has been folded by ICF.  We also discard an
5883           // EXIDX section with error, the output does not matter in this
5884           // case.  We do this to avoid triggering asserts.
5885           Arm_relobj<big_endian>* arm_relobj =
5886             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5887           const Arm_exidx_input_section* exidx_input_section =
5888             arm_relobj->exidx_input_section_by_shndx(p->shndx());
5889           gold_assert(exidx_input_section != NULL);
5890           if (!exidx_input_section->has_errors())
5891             {
5892               unsigned int text_shndx = exidx_input_section->link();
5893               gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5894             }
5895
5896           // Remove this from link.  We also need to recount the
5897           // local symbols.
5898           p->relobj()->set_output_section(p->shndx(), NULL);
5899           arm_relobj->set_output_local_symbol_count_needs_update();
5900         }
5901     }
5902     
5903   // Link exidx output section to the first seen output section and
5904   // set correct entry size.
5905   this->set_link_section(exidx_fixup.first_output_text_section());
5906   this->set_entsize(8);
5907
5908   // Make changes permanent.
5909   this->save_states();
5910   this->set_section_offsets_need_adjustment();
5911 }
5912
5913 // Link EXIDX output sections to text output sections.
5914
5915 template<bool big_endian>
5916 void
5917 Arm_output_section<big_endian>::set_exidx_section_link()
5918 {
5919   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5920   if (!this->input_sections().empty())
5921     {
5922       Input_section_list::const_iterator p = this->input_sections().begin();
5923       Arm_relobj<big_endian>* arm_relobj =
5924         Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5925       unsigned exidx_shndx = p->shndx();
5926       const Arm_exidx_input_section* exidx_input_section =
5927         arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
5928       gold_assert(exidx_input_section != NULL);
5929       unsigned int text_shndx = exidx_input_section->link();
5930       Output_section* os = arm_relobj->output_section(text_shndx);
5931       this->set_link_section(os);
5932     }
5933 }
5934
5935 // Arm_relobj methods.
5936
5937 // Determine if an input section is scannable for stub processing.  SHDR is
5938 // the header of the section and SHNDX is the section index.  OS is the output
5939 // section for the input section and SYMTAB is the global symbol table used to
5940 // look up ICF information.
5941
5942 template<bool big_endian>
5943 bool
5944 Arm_relobj<big_endian>::section_is_scannable(
5945     const elfcpp::Shdr<32, big_endian>& shdr,
5946     unsigned int shndx,
5947     const Output_section* os,
5948     const Symbol_table* symtab)
5949 {
5950   // Skip any empty sections, unallocated sections or sections whose
5951   // type are not SHT_PROGBITS.
5952   if (shdr.get_sh_size() == 0
5953       || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
5954       || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
5955     return false;
5956
5957   // Skip any discarded or ICF'ed sections.
5958   if (os == NULL || symtab->is_section_folded(this, shndx))
5959     return false;
5960
5961   // If this requires special offset handling, check to see if it is
5962   // a relaxed section.  If this is not, then it is a merged section that
5963   // we cannot handle.
5964   if (this->is_output_section_offset_invalid(shndx))
5965     {
5966       const Output_relaxed_input_section* poris =
5967         os->find_relaxed_input_section(this, shndx);
5968       if (poris == NULL)
5969         return false;
5970     }
5971
5972   return true;
5973 }
5974
5975 // Determine if we want to scan the SHNDX-th section for relocation stubs.
5976 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
5977
5978 template<bool big_endian>
5979 bool
5980 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
5981     const elfcpp::Shdr<32, big_endian>& shdr,
5982     const Relobj::Output_sections& out_sections,
5983     const Symbol_table* symtab,
5984     const unsigned char* pshdrs)
5985 {
5986   unsigned int sh_type = shdr.get_sh_type();
5987   if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
5988     return false;
5989
5990   // Ignore empty section.
5991   off_t sh_size = shdr.get_sh_size();
5992   if (sh_size == 0)
5993     return false;
5994
5995   // Ignore reloc section with unexpected symbol table.  The
5996   // error will be reported in the final link.
5997   if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
5998     return false;
5999
6000   unsigned int reloc_size;
6001   if (sh_type == elfcpp::SHT_REL)
6002     reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6003   else
6004     reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6005
6006   // Ignore reloc section with unexpected entsize or uneven size.
6007   // The error will be reported in the final link.
6008   if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6009     return false;
6010
6011   // Ignore reloc section with bad info.  This error will be
6012   // reported in the final link.
6013   unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6014   if (index >= this->shnum())
6015     return false;
6016
6017   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6018   const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6019   return this->section_is_scannable(text_shdr, index,
6020                                    out_sections[index], symtab);
6021 }
6022
6023 // Return the output address of either a plain input section or a relaxed
6024 // input section.  SHNDX is the section index.  We define and use this
6025 // instead of calling Output_section::output_address because that is slow
6026 // for large output.
6027
6028 template<bool big_endian>
6029 Arm_address
6030 Arm_relobj<big_endian>::simple_input_section_output_address(
6031     unsigned int shndx,
6032     Output_section* os)
6033 {
6034   if (this->is_output_section_offset_invalid(shndx))
6035     {
6036       const Output_relaxed_input_section* poris =
6037         os->find_relaxed_input_section(this, shndx);
6038       // We do not handle merged sections here.
6039       gold_assert(poris != NULL);
6040       return poris->address();
6041     }
6042   else
6043     return os->address() + this->get_output_section_offset(shndx);
6044 }
6045
6046 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6047 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6048
6049 template<bool big_endian>
6050 bool
6051 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6052     const elfcpp::Shdr<32, big_endian>& shdr,
6053     unsigned int shndx,
6054     Output_section* os,
6055     const Symbol_table* symtab)
6056 {
6057   if (!this->section_is_scannable(shdr, shndx, os, symtab))
6058     return false;
6059
6060   // If the section does not cross any 4K-boundaries, it does not need to
6061   // be scanned.
6062   Arm_address address = this->simple_input_section_output_address(shndx, os);
6063   if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6064     return false;
6065
6066   return true;
6067 }
6068
6069 // Scan a section for Cortex-A8 workaround.
6070
6071 template<bool big_endian>
6072 void
6073 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6074     const elfcpp::Shdr<32, big_endian>& shdr,
6075     unsigned int shndx,
6076     Output_section* os,
6077     Target_arm<big_endian>* arm_target)
6078 {
6079   // Look for the first mapping symbol in this section.  It should be
6080   // at (shndx, 0).
6081   Mapping_symbol_position section_start(shndx, 0);
6082   typename Mapping_symbols_info::const_iterator p =
6083     this->mapping_symbols_info_.lower_bound(section_start);
6084
6085   // There are no mapping symbols for this section.  Treat it as a data-only
6086   // section.  Issue a warning if section is marked as containing
6087   // instructions.
6088   if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6089     {
6090       if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6091         gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6092                        "erratum because it has no mapping symbols."),
6093                      shndx, this->name().c_str());
6094       return;
6095     }
6096
6097   Arm_address output_address =
6098     this->simple_input_section_output_address(shndx, os);
6099
6100   // Get the section contents.
6101   section_size_type input_view_size = 0;
6102   const unsigned char* input_view =
6103     this->section_contents(shndx, &input_view_size, false);
6104
6105   // We need to go through the mapping symbols to determine what to
6106   // scan.  There are two reasons.  First, we should look at THUMB code and
6107   // THUMB code only.  Second, we only want to look at the 4K-page boundary
6108   // to speed up the scanning.
6109   
6110   while (p != this->mapping_symbols_info_.end()
6111         && p->first.first == shndx)
6112     {
6113       typename Mapping_symbols_info::const_iterator next =
6114         this->mapping_symbols_info_.upper_bound(p->first);
6115
6116       // Only scan part of a section with THUMB code.
6117       if (p->second == 't')
6118         {
6119           // Determine the end of this range.
6120           section_size_type span_start =
6121             convert_to_section_size_type(p->first.second);
6122           section_size_type span_end;
6123           if (next != this->mapping_symbols_info_.end()
6124               && next->first.first == shndx)
6125             span_end = convert_to_section_size_type(next->first.second);
6126           else
6127             span_end = convert_to_section_size_type(shdr.get_sh_size());
6128           
6129           if (((span_start + output_address) & ~0xfffUL)
6130               != ((span_end + output_address - 1) & ~0xfffUL))
6131             {
6132               arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6133                                                           span_start, span_end,
6134                                                           input_view,
6135                                                           output_address);
6136             }
6137         }
6138
6139       p = next; 
6140     }
6141 }
6142
6143 // Scan relocations for stub generation.
6144
6145 template<bool big_endian>
6146 void
6147 Arm_relobj<big_endian>::scan_sections_for_stubs(
6148     Target_arm<big_endian>* arm_target,
6149     const Symbol_table* symtab,
6150     const Layout* layout)
6151 {
6152   unsigned int shnum = this->shnum();
6153   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6154
6155   // Read the section headers.
6156   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6157                                                shnum * shdr_size,
6158                                                true, true);
6159
6160   // To speed up processing, we set up hash tables for fast lookup of
6161   // input offsets to output addresses.
6162   this->initialize_input_to_output_maps();
6163
6164   const Relobj::Output_sections& out_sections(this->output_sections());
6165
6166   Relocate_info<32, big_endian> relinfo;
6167   relinfo.symtab = symtab;
6168   relinfo.layout = layout;
6169   relinfo.object = this;
6170
6171   // Do relocation stubs scanning.
6172   const unsigned char* p = pshdrs + shdr_size;
6173   for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6174     {
6175       const elfcpp::Shdr<32, big_endian> shdr(p);
6176       if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6177                                                   pshdrs))
6178         {
6179           unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6180           Arm_address output_offset = this->get_output_section_offset(index);
6181           Arm_address output_address;
6182           if (output_offset != invalid_address)
6183             output_address = out_sections[index]->address() + output_offset;
6184           else
6185             {
6186               // Currently this only happens for a relaxed section.
6187               const Output_relaxed_input_section* poris =
6188               out_sections[index]->find_relaxed_input_section(this, index);
6189               gold_assert(poris != NULL);
6190               output_address = poris->address();
6191             }
6192
6193           // Get the relocations.
6194           const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6195                                                         shdr.get_sh_size(),
6196                                                         true, false);
6197
6198           // Get the section contents.  This does work for the case in which
6199           // we modify the contents of an input section.  We need to pass the
6200           // output view under such circumstances.
6201           section_size_type input_view_size = 0;
6202           const unsigned char* input_view =
6203             this->section_contents(index, &input_view_size, false);
6204
6205           relinfo.reloc_shndx = i;
6206           relinfo.data_shndx = index;
6207           unsigned int sh_type = shdr.get_sh_type();
6208           unsigned int reloc_size;
6209           if (sh_type == elfcpp::SHT_REL)
6210             reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6211           else
6212             reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6213
6214           Output_section* os = out_sections[index];
6215           arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6216                                              shdr.get_sh_size() / reloc_size,
6217                                              os,
6218                                              output_offset == invalid_address,
6219                                              input_view, output_address,
6220                                              input_view_size);
6221         }
6222     }
6223
6224   // Do Cortex-A8 erratum stubs scanning.  This has to be done for a section
6225   // after its relocation section, if there is one, is processed for
6226   // relocation stubs.  Merging this loop with the one above would have been
6227   // complicated since we would have had to make sure that relocation stub
6228   // scanning is done first.
6229   if (arm_target->fix_cortex_a8())
6230     {
6231       const unsigned char* p = pshdrs + shdr_size;
6232       for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6233         {
6234           const elfcpp::Shdr<32, big_endian> shdr(p);
6235           if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6236                                                           out_sections[i],
6237                                                           symtab))
6238             this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6239                                                      arm_target);
6240         }
6241     }
6242
6243   // After we've done the relocations, we release the hash tables,
6244   // since we no longer need them.
6245   this->free_input_to_output_maps();
6246 }
6247
6248 // Count the local symbols.  The ARM backend needs to know if a symbol
6249 // is a THUMB function or not.  For global symbols, it is easy because
6250 // the Symbol object keeps the ELF symbol type.  For local symbol it is
6251 // harder because we cannot access this information.   So we override the
6252 // do_count_local_symbol in parent and scan local symbols to mark
6253 // THUMB functions.  This is not the most efficient way but I do not want to
6254 // slow down other ports by calling a per symbol targer hook inside
6255 // Sized_relobj<size, big_endian>::do_count_local_symbols. 
6256
6257 template<bool big_endian>
6258 void
6259 Arm_relobj<big_endian>::do_count_local_symbols(
6260     Stringpool_template<char>* pool,
6261     Stringpool_template<char>* dynpool)
6262 {
6263   // We need to fix-up the values of any local symbols whose type are
6264   // STT_ARM_TFUNC.
6265   
6266   // Ask parent to count the local symbols.
6267   Sized_relobj<32, big_endian>::do_count_local_symbols(pool, dynpool);
6268   const unsigned int loccount = this->local_symbol_count();
6269   if (loccount == 0)
6270     return;
6271
6272   // Intialize the thumb function bit-vector.
6273   std::vector<bool> empty_vector(loccount, false);
6274   this->local_symbol_is_thumb_function_.swap(empty_vector);
6275
6276   // Read the symbol table section header.
6277   const unsigned int symtab_shndx = this->symtab_shndx();
6278   elfcpp::Shdr<32, big_endian>
6279       symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6280   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6281
6282   // Read the local symbols.
6283   const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6284   gold_assert(loccount == symtabshdr.get_sh_info());
6285   off_t locsize = loccount * sym_size;
6286   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6287                                               locsize, true, true);
6288
6289   // For mapping symbol processing, we need to read the symbol names.
6290   unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6291   if (strtab_shndx >= this->shnum())
6292     {
6293       this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6294       return;
6295     }
6296
6297   elfcpp::Shdr<32, big_endian>
6298     strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6299   if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6300     {
6301       this->error(_("symbol table name section has wrong type: %u"),
6302                   static_cast<unsigned int>(strtabshdr.get_sh_type()));
6303       return;
6304     }
6305   const char* pnames =
6306     reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6307                                                  strtabshdr.get_sh_size(),
6308                                                  false, false));
6309
6310   // Loop over the local symbols and mark any local symbols pointing
6311   // to THUMB functions.
6312
6313   // Skip the first dummy symbol.
6314   psyms += sym_size;
6315   typename Sized_relobj<32, big_endian>::Local_values* plocal_values =
6316     this->local_values();
6317   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6318     {
6319       elfcpp::Sym<32, big_endian> sym(psyms);
6320       elfcpp::STT st_type = sym.get_st_type();
6321       Symbol_value<32>& lv((*plocal_values)[i]);
6322       Arm_address input_value = lv.input_value();
6323
6324       // Check to see if this is a mapping symbol.
6325       const char* sym_name = pnames + sym.get_st_name();
6326       if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6327         {
6328           bool is_ordinary;
6329           unsigned int input_shndx =
6330             this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6331           gold_assert(is_ordinary);
6332
6333           // Strip of LSB in case this is a THUMB symbol.
6334           Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6335           this->mapping_symbols_info_[msp] = sym_name[1];
6336         }
6337
6338       if (st_type == elfcpp::STT_ARM_TFUNC
6339           || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6340         {
6341           // This is a THUMB function.  Mark this and canonicalize the
6342           // symbol value by setting LSB.
6343           this->local_symbol_is_thumb_function_[i] = true;
6344           if ((input_value & 1) == 0)
6345             lv.set_input_value(input_value | 1);
6346         }
6347     }
6348 }
6349
6350 // Relocate sections.
6351 template<bool big_endian>
6352 void
6353 Arm_relobj<big_endian>::do_relocate_sections(
6354     const Symbol_table* symtab,
6355     const Layout* layout,
6356     const unsigned char* pshdrs,
6357     Output_file* of,
6358     typename Sized_relobj<32, big_endian>::Views* pviews)
6359 {
6360   // Call parent to relocate sections.
6361   Sized_relobj<32, big_endian>::do_relocate_sections(symtab, layout, pshdrs,
6362                                                      of, pviews); 
6363
6364   // We do not generate stubs if doing a relocatable link.
6365   if (parameters->options().relocatable())
6366     return;
6367
6368   // Relocate stub tables.
6369   unsigned int shnum = this->shnum();
6370
6371   Target_arm<big_endian>* arm_target =
6372     Target_arm<big_endian>::default_target();
6373
6374   Relocate_info<32, big_endian> relinfo;
6375   relinfo.symtab = symtab;
6376   relinfo.layout = layout;
6377   relinfo.object = this;
6378
6379   for (unsigned int i = 1; i < shnum; ++i)
6380     {
6381       Arm_input_section<big_endian>* arm_input_section =
6382         arm_target->find_arm_input_section(this, i);
6383
6384       if (arm_input_section != NULL
6385           && arm_input_section->is_stub_table_owner()
6386           && !arm_input_section->stub_table()->empty())
6387         {
6388           // We cannot discard a section if it owns a stub table.
6389           Output_section* os = this->output_section(i);
6390           gold_assert(os != NULL);
6391
6392           relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6393           relinfo.reloc_shdr = NULL;
6394           relinfo.data_shndx = i;
6395           relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6396
6397           gold_assert((*pviews)[i].view != NULL);
6398
6399           // We are passed the output section view.  Adjust it to cover the
6400           // stub table only.
6401           Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6402           gold_assert((stub_table->address() >= (*pviews)[i].address)
6403                       && ((stub_table->address() + stub_table->data_size())
6404                           <= (*pviews)[i].address + (*pviews)[i].view_size));
6405
6406           off_t offset = stub_table->address() - (*pviews)[i].address;
6407           unsigned char* view = (*pviews)[i].view + offset;
6408           Arm_address address = stub_table->address();
6409           section_size_type view_size = stub_table->data_size();
6410  
6411           stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6412                                      view_size);
6413         }
6414
6415       // Apply Cortex A8 workaround if applicable.
6416       if (this->section_has_cortex_a8_workaround(i))
6417         {
6418           unsigned char* view = (*pviews)[i].view;
6419           Arm_address view_address = (*pviews)[i].address;
6420           section_size_type view_size = (*pviews)[i].view_size;
6421           Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6422
6423           // Adjust view to cover section.
6424           Output_section* os = this->output_section(i);
6425           gold_assert(os != NULL);
6426           Arm_address section_address =
6427             this->simple_input_section_output_address(i, os);
6428           uint64_t section_size = this->section_size(i);
6429
6430           gold_assert(section_address >= view_address
6431                       && ((section_address + section_size)
6432                           <= (view_address + view_size)));
6433
6434           unsigned char* section_view = view + (section_address - view_address);
6435
6436           // Apply the Cortex-A8 workaround to the output address range
6437           // corresponding to this input section.
6438           stub_table->apply_cortex_a8_workaround_to_address_range(
6439               arm_target,
6440               section_view,
6441               section_address,
6442               section_size);
6443         }
6444     }
6445 }
6446
6447 // Find the linked text section of an EXIDX section by looking the the first
6448 // relocation.  4.4.1 of the EHABI specifications says that an EXIDX section
6449 // must be linked to to its associated code section via the sh_link field of
6450 // its section header.  However, some tools are broken and the link is not
6451 // always set.  LD just drops such an EXIDX section silently, causing the
6452 // associated code not unwindabled.   Here we try a little bit harder to
6453 // discover the linked code section.
6454 //
6455 // PSHDR points to the section header of a relocation section of an EXIDX
6456 // section.  If we can find a linked text section, return true and
6457 // store the text section index in the location PSHNDX.  Otherwise
6458 // return false.
6459
6460 template<bool big_endian>
6461 bool
6462 Arm_relobj<big_endian>::find_linked_text_section(
6463     const unsigned char* pshdr,
6464     const unsigned char* psyms,
6465     unsigned int* pshndx)
6466 {
6467   elfcpp::Shdr<32, big_endian> shdr(pshdr);
6468   
6469   // If there is no relocation, we cannot find the linked text section.
6470   size_t reloc_size;
6471   if (shdr.get_sh_type() == elfcpp::SHT_REL)
6472       reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6473   else
6474       reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6475   size_t reloc_count = shdr.get_sh_size() / reloc_size;
6476  
6477   // Get the relocations.
6478   const unsigned char* prelocs =
6479       this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false); 
6480
6481   // Find the REL31 relocation for the first word of the first EXIDX entry.
6482   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6483     {
6484       Arm_address r_offset;
6485       typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6486       if (shdr.get_sh_type() == elfcpp::SHT_REL)
6487         {
6488           typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6489           r_info = reloc.get_r_info();
6490           r_offset = reloc.get_r_offset();
6491         }
6492       else
6493         {
6494           typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6495           r_info = reloc.get_r_info();
6496           r_offset = reloc.get_r_offset();
6497         }
6498
6499       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6500       if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6501         continue;
6502
6503       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6504       if (r_sym == 0
6505           || r_sym >= this->local_symbol_count()
6506           || r_offset != 0)
6507         continue;
6508
6509       // This is the relocation for the first word of the first EXIDX entry.
6510       // We expect to see a local section symbol.
6511       const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6512       elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6513       if (sym.get_st_type() == elfcpp::STT_SECTION)
6514         {
6515           bool is_ordinary;
6516           *pshndx =
6517             this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6518           gold_assert(is_ordinary);
6519           return true;
6520         }
6521       else
6522         return false;
6523     }
6524
6525   return false;
6526 }
6527
6528 // Make an EXIDX input section object for an EXIDX section whose index is
6529 // SHNDX.  SHDR is the section header of the EXIDX section and TEXT_SHNDX
6530 // is the section index of the linked text section.
6531
6532 template<bool big_endian>
6533 void
6534 Arm_relobj<big_endian>::make_exidx_input_section(
6535     unsigned int shndx,
6536     const elfcpp::Shdr<32, big_endian>& shdr,
6537     unsigned int text_shndx,
6538     const elfcpp::Shdr<32, big_endian>& text_shdr)
6539 {
6540   // Create an Arm_exidx_input_section object for this EXIDX section.
6541   Arm_exidx_input_section* exidx_input_section =
6542     new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6543                                 shdr.get_sh_addralign());
6544
6545   gold_assert(this->exidx_section_map_[shndx] == NULL);
6546   this->exidx_section_map_[shndx] = exidx_input_section;
6547
6548   if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6549     {
6550       gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6551                  this->section_name(shndx).c_str(), shndx, text_shndx,
6552                  this->name().c_str());
6553       exidx_input_section->set_has_errors();
6554     } 
6555   else if (this->exidx_section_map_[text_shndx] != NULL)
6556     {
6557       unsigned other_exidx_shndx =
6558         this->exidx_section_map_[text_shndx]->shndx();
6559       gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6560                    "%s(%u) in %s"),
6561                  this->section_name(shndx).c_str(), shndx,
6562                  this->section_name(other_exidx_shndx).c_str(),
6563                  other_exidx_shndx, this->section_name(text_shndx).c_str(),
6564                  text_shndx, this->name().c_str());
6565       exidx_input_section->set_has_errors();
6566     }
6567   else
6568      this->exidx_section_map_[text_shndx] = exidx_input_section;
6569
6570   // Check section flags of text section.
6571   if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6572     {
6573       gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6574                    " in %s"),
6575                  this->section_name(shndx).c_str(), shndx,
6576                  this->section_name(text_shndx).c_str(), text_shndx,
6577                  this->name().c_str());
6578       exidx_input_section->set_has_errors();
6579     }
6580   else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6581     // I would like to make this an error but currenlty ld just ignores
6582     // this.
6583     gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6584                    "%s(%u) in %s"),
6585                  this->section_name(shndx).c_str(), shndx,
6586                  this->section_name(text_shndx).c_str(), text_shndx,
6587                  this->name().c_str());
6588 }
6589
6590 // Read the symbol information.
6591
6592 template<bool big_endian>
6593 void
6594 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6595 {
6596   // Call parent class to read symbol information.
6597   Sized_relobj<32, big_endian>::do_read_symbols(sd);
6598
6599   // If this input file is a binary file, it has no processor
6600   // specific flags and attributes section.
6601   Input_file::Format format = this->input_file()->format();
6602   if (format != Input_file::FORMAT_ELF)
6603     {
6604       gold_assert(format == Input_file::FORMAT_BINARY);
6605       this->merge_flags_and_attributes_ = false;
6606       return;
6607     }
6608
6609   // Read processor-specific flags in ELF file header.
6610   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6611                                               elfcpp::Elf_sizes<32>::ehdr_size,
6612                                               true, false);
6613   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6614   this->processor_specific_flags_ = ehdr.get_e_flags();
6615
6616   // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6617   // sections.
6618   std::vector<unsigned int> deferred_exidx_sections;
6619   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6620   const unsigned char* pshdrs = sd->section_headers->data();
6621   const unsigned char* ps = pshdrs + shdr_size;
6622   bool must_merge_flags_and_attributes = false;
6623   for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6624     {
6625       elfcpp::Shdr<32, big_endian> shdr(ps);
6626
6627       // Sometimes an object has no contents except the section name string
6628       // table and an empty symbol table with the undefined symbol.  We
6629       // don't want to merge processor-specific flags from such an object.
6630       if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6631         {
6632           // Symbol table is not empty.
6633           const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6634              elfcpp::Elf_sizes<32>::sym_size;
6635           if (shdr.get_sh_size() > sym_size)
6636             must_merge_flags_and_attributes = true;
6637         }
6638       else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6639         // If this is neither an empty symbol table nor a string table,
6640         // be conservative.
6641         must_merge_flags_and_attributes = true;
6642
6643       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6644         {
6645           gold_assert(this->attributes_section_data_ == NULL);
6646           section_offset_type section_offset = shdr.get_sh_offset();
6647           section_size_type section_size =
6648             convert_to_section_size_type(shdr.get_sh_size());
6649           File_view* view = this->get_lasting_view(section_offset,
6650                                                    section_size, true, false);
6651           this->attributes_section_data_ =
6652             new Attributes_section_data(view->data(), section_size);
6653         }
6654       else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6655         {
6656           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6657           if (text_shndx == elfcpp::SHN_UNDEF)
6658             deferred_exidx_sections.push_back(i);
6659           else
6660             {
6661               elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6662                                                      + text_shndx * shdr_size);
6663               this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6664             }
6665           // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6666           if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6667             gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6668                          this->section_name(i).c_str(), this->name().c_str());
6669         }
6670     }
6671
6672   // This is rare.
6673   if (!must_merge_flags_and_attributes)
6674     {
6675       gold_assert(deferred_exidx_sections.empty());
6676       this->merge_flags_and_attributes_ = false;
6677       return;
6678     }
6679
6680   // Some tools are broken and they do not set the link of EXIDX sections. 
6681   // We look at the first relocation to figure out the linked sections.
6682   if (!deferred_exidx_sections.empty())
6683     {
6684       // We need to go over the section headers again to find the mapping
6685       // from sections being relocated to their relocation sections.  This is
6686       // a bit inefficient as we could do that in the loop above.  However,
6687       // we do not expect any deferred EXIDX sections normally.  So we do not
6688       // want to slow down the most common path.
6689       typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6690       Reloc_map reloc_map;
6691       ps = pshdrs + shdr_size;
6692       for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6693         {
6694           elfcpp::Shdr<32, big_endian> shdr(ps);
6695           elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6696           if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6697             {
6698               unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6699               if (info_shndx >= this->shnum())
6700                 gold_error(_("relocation section %u has invalid info %u"),
6701                            i, info_shndx);
6702               Reloc_map::value_type value(info_shndx, i);
6703               std::pair<Reloc_map::iterator, bool> result =
6704                 reloc_map.insert(value);
6705               if (!result.second)
6706                 gold_error(_("section %u has multiple relocation sections "
6707                              "%u and %u"),
6708                            info_shndx, i, reloc_map[info_shndx]);
6709             }
6710         }
6711
6712       // Read the symbol table section header.
6713       const unsigned int symtab_shndx = this->symtab_shndx();
6714       elfcpp::Shdr<32, big_endian>
6715           symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6716       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6717
6718       // Read the local symbols.
6719       const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6720       const unsigned int loccount = this->local_symbol_count();
6721       gold_assert(loccount == symtabshdr.get_sh_info());
6722       off_t locsize = loccount * sym_size;
6723       const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6724                                                   locsize, true, true);
6725
6726       // Process the deferred EXIDX sections. 
6727       for(unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6728         {
6729           unsigned int shndx = deferred_exidx_sections[i];
6730           elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6731           unsigned int text_shndx = elfcpp::SHN_UNDEF;
6732           Reloc_map::const_iterator it = reloc_map.find(shndx);
6733           if (it != reloc_map.end())
6734             find_linked_text_section(pshdrs + it->second * shdr_size,
6735                                      psyms, &text_shndx);
6736           elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6737                                                  + text_shndx * shdr_size);
6738           this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6739         }
6740     }
6741 }
6742
6743 // Process relocations for garbage collection.  The ARM target uses .ARM.exidx
6744 // sections for unwinding.  These sections are referenced implicitly by 
6745 // text sections linked in the section headers.  If we ignore these implict
6746 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6747 // will be garbage-collected incorrectly.  Hence we override the same function
6748 // in the base class to handle these implicit references.
6749
6750 template<bool big_endian>
6751 void
6752 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6753                                              Layout* layout,
6754                                              Read_relocs_data* rd)
6755 {
6756   // First, call base class method to process relocations in this object.
6757   Sized_relobj<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6758
6759   // If --gc-sections is not specified, there is nothing more to do.
6760   // This happens when --icf is used but --gc-sections is not.
6761   if (!parameters->options().gc_sections())
6762     return;
6763   
6764   unsigned int shnum = this->shnum();
6765   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6766   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6767                                                shnum * shdr_size,
6768                                                true, true);
6769
6770   // Scan section headers for sections of type SHT_ARM_EXIDX.  Add references
6771   // to these from the linked text sections.
6772   const unsigned char* ps = pshdrs + shdr_size;
6773   for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6774     {
6775       elfcpp::Shdr<32, big_endian> shdr(ps);
6776       if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6777         {
6778           // Found an .ARM.exidx section, add it to the set of reachable
6779           // sections from its linked text section.
6780           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6781           symtab->gc()->add_reference(this, text_shndx, this, i);
6782         }
6783     }
6784 }
6785
6786 // Update output local symbol count.  Owing to EXIDX entry merging, some local
6787 // symbols  will be removed in output.  Adjust output local symbol count
6788 // accordingly.  We can only changed the static output local symbol count.  It
6789 // is too late to change the dynamic symbols.
6790
6791 template<bool big_endian>
6792 void
6793 Arm_relobj<big_endian>::update_output_local_symbol_count()
6794 {
6795   // Caller should check that this needs updating.  We want caller checking
6796   // because output_local_symbol_count_needs_update() is most likely inlined.
6797   gold_assert(this->output_local_symbol_count_needs_update_);
6798
6799   gold_assert(this->symtab_shndx() != -1U);
6800   if (this->symtab_shndx() == 0)
6801     {
6802       // This object has no symbols.  Weird but legal.
6803       return;
6804     }
6805
6806   // Read the symbol table section header.
6807   const unsigned int symtab_shndx = this->symtab_shndx();
6808   elfcpp::Shdr<32, big_endian>
6809     symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6810   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6811
6812   // Read the local symbols.
6813   const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6814   const unsigned int loccount = this->local_symbol_count();
6815   gold_assert(loccount == symtabshdr.get_sh_info());
6816   off_t locsize = loccount * sym_size;
6817   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6818                                               locsize, true, true);
6819
6820   // Loop over the local symbols.
6821
6822   typedef typename Sized_relobj<32, big_endian>::Output_sections
6823      Output_sections;
6824   const Output_sections& out_sections(this->output_sections());
6825   unsigned int shnum = this->shnum();
6826   unsigned int count = 0;
6827   // Skip the first, dummy, symbol.
6828   psyms += sym_size;
6829   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6830     {
6831       elfcpp::Sym<32, big_endian> sym(psyms);
6832
6833       Symbol_value<32>& lv((*this->local_values())[i]);
6834
6835       // This local symbol was already discarded by do_count_local_symbols.
6836       if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6837         continue;
6838
6839       bool is_ordinary;
6840       unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6841                                                   &is_ordinary);
6842
6843       if (shndx < shnum)
6844         {
6845           Output_section* os = out_sections[shndx];
6846
6847           // This local symbol no longer has an output section.  Discard it.
6848           if (os == NULL)
6849             {
6850               lv.set_no_output_symtab_entry();
6851               continue;
6852             }
6853
6854           // Currently we only discard parts of EXIDX input sections.
6855           // We explicitly check for a merged EXIDX input section to avoid
6856           // calling Output_section_data::output_offset unless necessary.
6857           if ((this->get_output_section_offset(shndx) == invalid_address)
6858               && (this->exidx_input_section_by_shndx(shndx) != NULL))
6859             {
6860               section_offset_type output_offset =
6861                 os->output_offset(this, shndx, lv.input_value());
6862               if (output_offset == -1)
6863                 {
6864                   // This symbol is defined in a part of an EXIDX input section
6865                   // that is discarded due to entry merging.
6866                   lv.set_no_output_symtab_entry();
6867                   continue;
6868                 }       
6869             }
6870         }
6871
6872       ++count;
6873     }
6874
6875   this->set_output_local_symbol_count(count);
6876   this->output_local_symbol_count_needs_update_ = false;
6877 }
6878
6879 // Arm_dynobj methods.
6880
6881 // Read the symbol information.
6882
6883 template<bool big_endian>
6884 void
6885 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6886 {
6887   // Call parent class to read symbol information.
6888   Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6889
6890   // Read processor-specific flags in ELF file header.
6891   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6892                                               elfcpp::Elf_sizes<32>::ehdr_size,
6893                                               true, false);
6894   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6895   this->processor_specific_flags_ = ehdr.get_e_flags();
6896
6897   // Read the attributes section if there is one.
6898   // We read from the end because gas seems to put it near the end of
6899   // the section headers.
6900   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6901   const unsigned char* ps =
6902     sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6903   for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6904     {
6905       elfcpp::Shdr<32, big_endian> shdr(ps);
6906       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6907         {
6908           section_offset_type section_offset = shdr.get_sh_offset();
6909           section_size_type section_size =
6910             convert_to_section_size_type(shdr.get_sh_size());
6911           File_view* view = this->get_lasting_view(section_offset,
6912                                                    section_size, true, false);
6913           this->attributes_section_data_ =
6914             new Attributes_section_data(view->data(), section_size);
6915           break;
6916         }
6917     }
6918 }
6919
6920 // Stub_addend_reader methods.
6921
6922 // Read the addend of a REL relocation of type R_TYPE at VIEW.
6923
6924 template<bool big_endian>
6925 elfcpp::Elf_types<32>::Elf_Swxword
6926 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
6927     unsigned int r_type,
6928     const unsigned char* view,
6929     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
6930 {
6931   typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
6932   
6933   switch (r_type)
6934     {
6935     case elfcpp::R_ARM_CALL:
6936     case elfcpp::R_ARM_JUMP24:
6937     case elfcpp::R_ARM_PLT32:
6938       {
6939         typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
6940         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6941         Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
6942         return utils::sign_extend<26>(val << 2);
6943       }
6944
6945     case elfcpp::R_ARM_THM_CALL:
6946     case elfcpp::R_ARM_THM_JUMP24:
6947     case elfcpp::R_ARM_THM_XPC22:
6948       {
6949         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
6950         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6951         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
6952         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
6953         return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
6954       }
6955
6956     case elfcpp::R_ARM_THM_JUMP19:
6957       {
6958         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
6959         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6960         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
6961         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
6962         return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
6963       }
6964
6965     default:
6966       gold_unreachable();
6967     }
6968 }
6969
6970 // Arm_output_data_got methods.
6971
6972 // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
6973 // The first one is initialized to be 1, which is the module index for
6974 // the main executable and the second one 0.  A reloc of the type
6975 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
6976 // be applied by gold.  GSYM is a global symbol.
6977 //
6978 template<bool big_endian>
6979 void
6980 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
6981     unsigned int got_type,
6982     Symbol* gsym)
6983 {
6984   if (gsym->has_got_offset(got_type))
6985     return;
6986
6987   // We are doing a static link.  Just mark it as belong to module 1,
6988   // the executable.
6989   unsigned int got_offset = this->add_constant(1);
6990   gsym->set_got_offset(got_type, got_offset); 
6991   got_offset = this->add_constant(0);
6992   this->static_relocs_.push_back(Static_reloc(got_offset,
6993                                               elfcpp::R_ARM_TLS_DTPOFF32,
6994                                               gsym));
6995 }
6996
6997 // Same as the above but for a local symbol.
6998
6999 template<bool big_endian>
7000 void
7001 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7002   unsigned int got_type,
7003   Sized_relobj<32, big_endian>* object,
7004   unsigned int index)
7005 {
7006   if (object->local_has_got_offset(index, got_type))
7007     return;
7008
7009   // We are doing a static link.  Just mark it as belong to module 1,
7010   // the executable.
7011   unsigned int got_offset = this->add_constant(1);
7012   object->set_local_got_offset(index, got_type, got_offset);
7013   got_offset = this->add_constant(0);
7014   this->static_relocs_.push_back(Static_reloc(got_offset, 
7015                                               elfcpp::R_ARM_TLS_DTPOFF32, 
7016                                               object, index));
7017 }
7018
7019 template<bool big_endian>
7020 void
7021 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7022 {
7023   // Call parent to write out GOT.
7024   Output_data_got<32, big_endian>::do_write(of);
7025
7026   // We are done if there is no fix up.
7027   if (this->static_relocs_.empty())
7028     return;
7029
7030   gold_assert(parameters->doing_static_link());
7031
7032   const off_t offset = this->offset();
7033   const section_size_type oview_size =
7034     convert_to_section_size_type(this->data_size());
7035   unsigned char* const oview = of->get_output_view(offset, oview_size);
7036
7037   Output_segment* tls_segment = this->layout_->tls_segment();
7038   gold_assert(tls_segment != NULL);
7039   
7040   // The thread pointer $tp points to the TCB, which is followed by the
7041   // TLS.  So we need to adjust $tp relative addressing by this amount.
7042   Arm_address aligned_tcb_size =
7043     align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7044
7045   for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7046     {
7047       Static_reloc& reloc(this->static_relocs_[i]);
7048       
7049       Arm_address value;
7050       if (!reloc.symbol_is_global())
7051         {
7052           Sized_relobj<32, big_endian>* object = reloc.relobj();
7053           const Symbol_value<32>* psymval =
7054             reloc.relobj()->local_symbol(reloc.index());
7055
7056           // We are doing static linking.  Issue an error and skip this
7057           // relocation if the symbol is undefined or in a discarded_section.
7058           bool is_ordinary;
7059           unsigned int shndx = psymval->input_shndx(&is_ordinary);
7060           if ((shndx == elfcpp::SHN_UNDEF)
7061               || (is_ordinary
7062                   && shndx != elfcpp::SHN_UNDEF
7063                   && !object->is_section_included(shndx)
7064                   && !this->symbol_table_->is_section_folded(object, shndx)))
7065             {
7066               gold_error(_("undefined or discarded local symbol %u from "
7067                            " object %s in GOT"),
7068                          reloc.index(), reloc.relobj()->name().c_str());
7069               continue;
7070             }
7071           
7072           value = psymval->value(object, 0);
7073         }
7074       else
7075         {
7076           const Symbol* gsym = reloc.symbol();
7077           gold_assert(gsym != NULL);
7078           if (gsym->is_forwarder())
7079             gsym = this->symbol_table_->resolve_forwards(gsym);
7080
7081           // We are doing static linking.  Issue an error and skip this
7082           // relocation if the symbol is undefined or in a discarded_section
7083           // unless it is a weakly_undefined symbol.
7084           if ((gsym->is_defined_in_discarded_section()
7085                || gsym->is_undefined())
7086               && !gsym->is_weak_undefined())
7087             {
7088               gold_error(_("undefined or discarded symbol %s in GOT"),
7089                          gsym->name());
7090               continue;
7091             }
7092
7093           if (!gsym->is_weak_undefined())
7094             {
7095               const Sized_symbol<32>* sym =
7096                 static_cast<const Sized_symbol<32>*>(gsym);
7097               value = sym->value();
7098             }
7099           else
7100               value = 0;
7101         }
7102
7103       unsigned got_offset = reloc.got_offset();
7104       gold_assert(got_offset < oview_size);
7105
7106       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7107       Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7108       Valtype x;
7109       switch (reloc.r_type())
7110         {
7111         case elfcpp::R_ARM_TLS_DTPOFF32:
7112           x = value;
7113           break;
7114         case elfcpp::R_ARM_TLS_TPOFF32:
7115           x = value + aligned_tcb_size;
7116           break;
7117         default:
7118           gold_unreachable();
7119         }
7120       elfcpp::Swap<32, big_endian>::writeval(wv, x);
7121     }
7122
7123   of->write_output_view(offset, oview_size, oview);
7124 }
7125
7126 // A class to handle the PLT data.
7127
7128 template<bool big_endian>
7129 class Output_data_plt_arm : public Output_section_data
7130 {
7131  public:
7132   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7133     Reloc_section;
7134
7135   Output_data_plt_arm(Layout*, Output_data_space*);
7136
7137   // Add an entry to the PLT.
7138   void
7139   add_entry(Symbol* gsym);
7140
7141   // Return the .rel.plt section data.
7142   const Reloc_section*
7143   rel_plt() const
7144   { return this->rel_; }
7145
7146   // Return the number of PLT entries.
7147   unsigned int
7148   entry_count() const
7149   { return this->count_; }
7150
7151   // Return the offset of the first non-reserved PLT entry.
7152   static unsigned int
7153   first_plt_entry_offset()
7154   { return sizeof(first_plt_entry); }
7155
7156   // Return the size of a PLT entry.
7157   static unsigned int
7158   get_plt_entry_size()
7159   { return sizeof(plt_entry); }
7160
7161  protected:
7162   void
7163   do_adjust_output_section(Output_section* os);
7164
7165   // Write to a map file.
7166   void
7167   do_print_to_mapfile(Mapfile* mapfile) const
7168   { mapfile->print_output_data(this, _("** PLT")); }
7169
7170  private:
7171   // Template for the first PLT entry.
7172   static const uint32_t first_plt_entry[5];
7173
7174   // Template for subsequent PLT entries. 
7175   static const uint32_t plt_entry[3];
7176
7177   // Set the final size.
7178   void
7179   set_final_data_size()
7180   {
7181     this->set_data_size(sizeof(first_plt_entry)
7182                         + this->count_ * sizeof(plt_entry));
7183   }
7184
7185   // Write out the PLT data.
7186   void
7187   do_write(Output_file*);
7188
7189   // The reloc section.
7190   Reloc_section* rel_;
7191   // The .got.plt section.
7192   Output_data_space* got_plt_;
7193   // The number of PLT entries.
7194   unsigned int count_;
7195 };
7196
7197 // Create the PLT section.  The ordinary .got section is an argument,
7198 // since we need to refer to the start.  We also create our own .got
7199 // section just for PLT entries.
7200
7201 template<bool big_endian>
7202 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7203                                                      Output_data_space* got_plt)
7204   : Output_section_data(4), got_plt_(got_plt), count_(0)
7205 {
7206   this->rel_ = new Reloc_section(false);
7207   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7208                                   elfcpp::SHF_ALLOC, this->rel_,
7209                                   ORDER_DYNAMIC_PLT_RELOCS, false);
7210 }
7211
7212 template<bool big_endian>
7213 void
7214 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7215 {
7216   os->set_entsize(0);
7217 }
7218
7219 // Add an entry to the PLT.
7220
7221 template<bool big_endian>
7222 void
7223 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7224 {
7225   gold_assert(!gsym->has_plt_offset());
7226
7227   // Note that when setting the PLT offset we skip the initial
7228   // reserved PLT entry.
7229   gsym->set_plt_offset((this->count_) * sizeof(plt_entry)
7230                        + sizeof(first_plt_entry));
7231
7232   ++this->count_;
7233
7234   section_offset_type got_offset = this->got_plt_->current_data_size();
7235
7236   // Every PLT entry needs a GOT entry which points back to the PLT
7237   // entry (this will be changed by the dynamic linker, normally
7238   // lazily when the function is called).
7239   this->got_plt_->set_current_data_size(got_offset + 4);
7240
7241   // Every PLT entry needs a reloc.
7242   gsym->set_needs_dynsym_entry();
7243   this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7244                          got_offset);
7245
7246   // Note that we don't need to save the symbol.  The contents of the
7247   // PLT are independent of which symbols are used.  The symbols only
7248   // appear in the relocations.
7249 }
7250
7251 // ARM PLTs.
7252 // FIXME:  This is not very flexible.  Right now this has only been tested
7253 // on armv5te.  If we are to support additional architecture features like
7254 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7255
7256 // The first entry in the PLT.
7257 template<bool big_endian>
7258 const uint32_t Output_data_plt_arm<big_endian>::first_plt_entry[5] =
7259 {
7260   0xe52de004,   // str   lr, [sp, #-4]!
7261   0xe59fe004,   // ldr   lr, [pc, #4]
7262   0xe08fe00e,   // add   lr, pc, lr 
7263   0xe5bef008,   // ldr   pc, [lr, #8]!
7264   0x00000000,   // &GOT[0] - .
7265 };
7266
7267 // Subsequent entries in the PLT.
7268
7269 template<bool big_endian>
7270 const uint32_t Output_data_plt_arm<big_endian>::plt_entry[3] =
7271 {
7272   0xe28fc600,   // add   ip, pc, #0xNN00000
7273   0xe28cca00,   // add   ip, ip, #0xNN000
7274   0xe5bcf000,   // ldr   pc, [ip, #0xNNN]!
7275 };
7276
7277 // Write out the PLT.  This uses the hand-coded instructions above,
7278 // and adjusts them as needed.  This is all specified by the arm ELF
7279 // Processor Supplement.
7280
7281 template<bool big_endian>
7282 void
7283 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7284 {
7285   const off_t offset = this->offset();
7286   const section_size_type oview_size =
7287     convert_to_section_size_type(this->data_size());
7288   unsigned char* const oview = of->get_output_view(offset, oview_size);
7289
7290   const off_t got_file_offset = this->got_plt_->offset();
7291   const section_size_type got_size =
7292     convert_to_section_size_type(this->got_plt_->data_size());
7293   unsigned char* const got_view = of->get_output_view(got_file_offset,
7294                                                       got_size);
7295   unsigned char* pov = oview;
7296
7297   Arm_address plt_address = this->address();
7298   Arm_address got_address = this->got_plt_->address();
7299
7300   // Write first PLT entry.  All but the last word are constants.
7301   const size_t num_first_plt_words = (sizeof(first_plt_entry)
7302                                       / sizeof(plt_entry[0]));
7303   for (size_t i = 0; i < num_first_plt_words - 1; i++)
7304     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7305   // Last word in first PLT entry is &GOT[0] - .
7306   elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7307                                          got_address - (plt_address + 16));
7308   pov += sizeof(first_plt_entry);
7309
7310   unsigned char* got_pov = got_view;
7311
7312   memset(got_pov, 0, 12);
7313   got_pov += 12;
7314
7315   const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
7316   unsigned int plt_offset = sizeof(first_plt_entry);
7317   unsigned int plt_rel_offset = 0;
7318   unsigned int got_offset = 12;
7319   const unsigned int count = this->count_;
7320   for (unsigned int i = 0;
7321        i < count;
7322        ++i,
7323          pov += sizeof(plt_entry),
7324          got_pov += 4,
7325          plt_offset += sizeof(plt_entry),
7326          plt_rel_offset += rel_size,
7327          got_offset += 4)
7328     {
7329       // Set and adjust the PLT entry itself.
7330       int32_t offset = ((got_address + got_offset)
7331                          - (plt_address + plt_offset + 8));
7332
7333       gold_assert(offset >= 0 && offset < 0x0fffffff);
7334       uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7335       elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7336       uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7337       elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7338       uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7339       elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7340
7341       // Set the entry in the GOT.
7342       elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7343     }
7344
7345   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7346   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7347
7348   of->write_output_view(offset, oview_size, oview);
7349   of->write_output_view(got_file_offset, got_size, got_view);
7350 }
7351
7352 // Create a PLT entry for a global symbol.
7353
7354 template<bool big_endian>
7355 void
7356 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7357                                        Symbol* gsym)
7358 {
7359   if (gsym->has_plt_offset())
7360     return;
7361
7362   if (this->plt_ == NULL)
7363     {
7364       // Create the GOT sections first.
7365       this->got_section(symtab, layout);
7366
7367       this->plt_ = new Output_data_plt_arm<big_endian>(layout, this->got_plt_);
7368       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7369                                       (elfcpp::SHF_ALLOC
7370                                        | elfcpp::SHF_EXECINSTR),
7371                                       this->plt_, ORDER_PLT, false);
7372     }
7373   this->plt_->add_entry(gsym);
7374 }
7375
7376 // Return the number of entries in the PLT.
7377
7378 template<bool big_endian>
7379 unsigned int
7380 Target_arm<big_endian>::plt_entry_count() const
7381 {
7382   if (this->plt_ == NULL)
7383     return 0;
7384   return this->plt_->entry_count();
7385 }
7386
7387 // Return the offset of the first non-reserved PLT entry.
7388
7389 template<bool big_endian>
7390 unsigned int
7391 Target_arm<big_endian>::first_plt_entry_offset() const
7392 {
7393   return Output_data_plt_arm<big_endian>::first_plt_entry_offset();
7394 }
7395
7396 // Return the size of each PLT entry.
7397
7398 template<bool big_endian>
7399 unsigned int
7400 Target_arm<big_endian>::plt_entry_size() const
7401 {
7402   return Output_data_plt_arm<big_endian>::get_plt_entry_size();
7403 }
7404
7405 // Get the section to use for TLS_DESC relocations.
7406
7407 template<bool big_endian>
7408 typename Target_arm<big_endian>::Reloc_section*
7409 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7410 {
7411   return this->plt_section()->rel_tls_desc(layout);
7412 }
7413
7414 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7415
7416 template<bool big_endian>
7417 void
7418 Target_arm<big_endian>::define_tls_base_symbol(
7419     Symbol_table* symtab,
7420     Layout* layout)
7421 {
7422   if (this->tls_base_symbol_defined_)
7423     return;
7424
7425   Output_segment* tls_segment = layout->tls_segment();
7426   if (tls_segment != NULL)
7427     {
7428       bool is_exec = parameters->options().output_is_executable();
7429       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7430                                        Symbol_table::PREDEFINED,
7431                                        tls_segment, 0, 0,
7432                                        elfcpp::STT_TLS,
7433                                        elfcpp::STB_LOCAL,
7434                                        elfcpp::STV_HIDDEN, 0,
7435                                        (is_exec
7436                                         ? Symbol::SEGMENT_END
7437                                         : Symbol::SEGMENT_START),
7438                                        true);
7439     }
7440   this->tls_base_symbol_defined_ = true;
7441 }
7442
7443 // Create a GOT entry for the TLS module index.
7444
7445 template<bool big_endian>
7446 unsigned int
7447 Target_arm<big_endian>::got_mod_index_entry(
7448     Symbol_table* symtab,
7449     Layout* layout,
7450     Sized_relobj<32, big_endian>* object)
7451 {
7452   if (this->got_mod_index_offset_ == -1U)
7453     {
7454       gold_assert(symtab != NULL && layout != NULL && object != NULL);
7455       Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7456       unsigned int got_offset;
7457       if (!parameters->doing_static_link())
7458         {
7459           got_offset = got->add_constant(0);
7460           Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7461           rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7462                              got_offset);
7463         }
7464       else
7465         {
7466           // We are doing a static link.  Just mark it as belong to module 1,
7467           // the executable.
7468           got_offset = got->add_constant(1);
7469         }
7470
7471       got->add_constant(0);
7472       this->got_mod_index_offset_ = got_offset;
7473     }
7474   return this->got_mod_index_offset_;
7475 }
7476
7477 // Optimize the TLS relocation type based on what we know about the
7478 // symbol.  IS_FINAL is true if the final address of this symbol is
7479 // known at link time.
7480
7481 template<bool big_endian>
7482 tls::Tls_optimization
7483 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7484 {
7485   // FIXME: Currently we do not do any TLS optimization.
7486   return tls::TLSOPT_NONE;
7487 }
7488
7489 // Report an unsupported relocation against a local symbol.
7490
7491 template<bool big_endian>
7492 void
7493 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7494     Sized_relobj<32, big_endian>* object,
7495     unsigned int r_type)
7496 {
7497   gold_error(_("%s: unsupported reloc %u against local symbol"),
7498              object->name().c_str(), r_type);
7499 }
7500
7501 // We are about to emit a dynamic relocation of type R_TYPE.  If the
7502 // dynamic linker does not support it, issue an error.  The GNU linker
7503 // only issues a non-PIC error for an allocated read-only section.
7504 // Here we know the section is allocated, but we don't know that it is
7505 // read-only.  But we check for all the relocation types which the
7506 // glibc dynamic linker supports, so it seems appropriate to issue an
7507 // error even if the section is not read-only.
7508
7509 template<bool big_endian>
7510 void
7511 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7512                                             unsigned int r_type)
7513 {
7514   switch (r_type)
7515     {
7516     // These are the relocation types supported by glibc for ARM.
7517     case elfcpp::R_ARM_RELATIVE:
7518     case elfcpp::R_ARM_COPY:
7519     case elfcpp::R_ARM_GLOB_DAT:
7520     case elfcpp::R_ARM_JUMP_SLOT:
7521     case elfcpp::R_ARM_ABS32:
7522     case elfcpp::R_ARM_ABS32_NOI:
7523     case elfcpp::R_ARM_PC24:
7524     // FIXME: The following 3 types are not supported by Android's dynamic
7525     // linker.
7526     case elfcpp::R_ARM_TLS_DTPMOD32:
7527     case elfcpp::R_ARM_TLS_DTPOFF32:
7528     case elfcpp::R_ARM_TLS_TPOFF32:
7529       return;
7530
7531     default:
7532       {
7533         // This prevents us from issuing more than one error per reloc
7534         // section.  But we can still wind up issuing more than one
7535         // error per object file.
7536         if (this->issued_non_pic_error_)
7537           return;
7538         const Arm_reloc_property* reloc_property =
7539           arm_reloc_property_table->get_reloc_property(r_type);
7540         gold_assert(reloc_property != NULL);
7541         object->error(_("requires unsupported dynamic reloc %s; "
7542                       "recompile with -fPIC"),
7543                       reloc_property->name().c_str());
7544         this->issued_non_pic_error_ = true;
7545         return;
7546       }
7547
7548     case elfcpp::R_ARM_NONE:
7549       gold_unreachable();
7550     }
7551 }
7552
7553 // Scan a relocation for a local symbol.
7554 // FIXME: This only handles a subset of relocation types used by Android
7555 // on ARM v5te devices.
7556
7557 template<bool big_endian>
7558 inline void
7559 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7560                                     Layout* layout,
7561                                     Target_arm* target,
7562                                     Sized_relobj<32, big_endian>* object,
7563                                     unsigned int data_shndx,
7564                                     Output_section* output_section,
7565                                     const elfcpp::Rel<32, big_endian>& reloc,
7566                                     unsigned int r_type,
7567                                     const elfcpp::Sym<32, big_endian>& lsym)
7568 {
7569   r_type = get_real_reloc_type(r_type);
7570   switch (r_type)
7571     {
7572     case elfcpp::R_ARM_NONE:
7573     case elfcpp::R_ARM_V4BX:
7574     case elfcpp::R_ARM_GNU_VTENTRY:
7575     case elfcpp::R_ARM_GNU_VTINHERIT:
7576       break;
7577
7578     case elfcpp::R_ARM_ABS32:
7579     case elfcpp::R_ARM_ABS32_NOI:
7580       // If building a shared library (or a position-independent
7581       // executable), we need to create a dynamic relocation for
7582       // this location. The relocation applied at link time will
7583       // apply the link-time value, so we flag the location with
7584       // an R_ARM_RELATIVE relocation so the dynamic loader can
7585       // relocate it easily.
7586       if (parameters->options().output_is_position_independent())
7587         {
7588           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7589           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7590           // If we are to add more other reloc types than R_ARM_ABS32,
7591           // we need to add check_non_pic(object, r_type) here.
7592           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7593                                       output_section, data_shndx,
7594                                       reloc.get_r_offset());
7595         }
7596       break;
7597
7598     case elfcpp::R_ARM_ABS16:
7599     case elfcpp::R_ARM_ABS12:
7600     case elfcpp::R_ARM_THM_ABS5:
7601     case elfcpp::R_ARM_ABS8:
7602     case elfcpp::R_ARM_BASE_ABS:
7603     case elfcpp::R_ARM_MOVW_ABS_NC:
7604     case elfcpp::R_ARM_MOVT_ABS:
7605     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7606     case elfcpp::R_ARM_THM_MOVT_ABS:
7607       // If building a shared library (or a position-independent
7608       // executable), we need to create a dynamic relocation for
7609       // this location. Because the addend needs to remain in the
7610       // data section, we need to be careful not to apply this
7611       // relocation statically.
7612       if (parameters->options().output_is_position_independent())
7613         {
7614           check_non_pic(object, r_type);
7615           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7616           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7617           if (lsym.get_st_type() != elfcpp::STT_SECTION)
7618             rel_dyn->add_local(object, r_sym, r_type, output_section,
7619                                data_shndx, reloc.get_r_offset());
7620           else
7621             {
7622               gold_assert(lsym.get_st_value() == 0);
7623               unsigned int shndx = lsym.get_st_shndx();
7624               bool is_ordinary;
7625               shndx = object->adjust_sym_shndx(r_sym, shndx,
7626                                                &is_ordinary);
7627               if (!is_ordinary)
7628                 object->error(_("section symbol %u has bad shndx %u"),
7629                               r_sym, shndx);
7630               else
7631                 rel_dyn->add_local_section(object, shndx,
7632                                            r_type, output_section,
7633                                            data_shndx, reloc.get_r_offset());
7634             }
7635         }
7636       break;
7637
7638     case elfcpp::R_ARM_REL32:
7639     case elfcpp::R_ARM_LDR_PC_G0:
7640     case elfcpp::R_ARM_SBREL32:
7641     case elfcpp::R_ARM_THM_CALL:
7642     case elfcpp::R_ARM_THM_PC8:
7643     case elfcpp::R_ARM_BASE_PREL:
7644     case elfcpp::R_ARM_PLT32:
7645     case elfcpp::R_ARM_CALL:
7646     case elfcpp::R_ARM_JUMP24:
7647     case elfcpp::R_ARM_THM_JUMP24:
7648     case elfcpp::R_ARM_SBREL31:
7649     case elfcpp::R_ARM_PREL31:
7650     case elfcpp::R_ARM_MOVW_PREL_NC:
7651     case elfcpp::R_ARM_MOVT_PREL:
7652     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7653     case elfcpp::R_ARM_THM_MOVT_PREL:
7654     case elfcpp::R_ARM_THM_JUMP19:
7655     case elfcpp::R_ARM_THM_JUMP6:
7656     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7657     case elfcpp::R_ARM_THM_PC12:
7658     case elfcpp::R_ARM_REL32_NOI:
7659     case elfcpp::R_ARM_ALU_PC_G0_NC:
7660     case elfcpp::R_ARM_ALU_PC_G0:
7661     case elfcpp::R_ARM_ALU_PC_G1_NC:
7662     case elfcpp::R_ARM_ALU_PC_G1:
7663     case elfcpp::R_ARM_ALU_PC_G2:
7664     case elfcpp::R_ARM_LDR_PC_G1:
7665     case elfcpp::R_ARM_LDR_PC_G2:
7666     case elfcpp::R_ARM_LDRS_PC_G0:
7667     case elfcpp::R_ARM_LDRS_PC_G1:
7668     case elfcpp::R_ARM_LDRS_PC_G2:
7669     case elfcpp::R_ARM_LDC_PC_G0:
7670     case elfcpp::R_ARM_LDC_PC_G1:
7671     case elfcpp::R_ARM_LDC_PC_G2:
7672     case elfcpp::R_ARM_ALU_SB_G0_NC:
7673     case elfcpp::R_ARM_ALU_SB_G0:
7674     case elfcpp::R_ARM_ALU_SB_G1_NC:
7675     case elfcpp::R_ARM_ALU_SB_G1:
7676     case elfcpp::R_ARM_ALU_SB_G2:
7677     case elfcpp::R_ARM_LDR_SB_G0:
7678     case elfcpp::R_ARM_LDR_SB_G1:
7679     case elfcpp::R_ARM_LDR_SB_G2:
7680     case elfcpp::R_ARM_LDRS_SB_G0:
7681     case elfcpp::R_ARM_LDRS_SB_G1:
7682     case elfcpp::R_ARM_LDRS_SB_G2:
7683     case elfcpp::R_ARM_LDC_SB_G0:
7684     case elfcpp::R_ARM_LDC_SB_G1:
7685     case elfcpp::R_ARM_LDC_SB_G2:
7686     case elfcpp::R_ARM_MOVW_BREL_NC:
7687     case elfcpp::R_ARM_MOVT_BREL:
7688     case elfcpp::R_ARM_MOVW_BREL:
7689     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7690     case elfcpp::R_ARM_THM_MOVT_BREL:
7691     case elfcpp::R_ARM_THM_MOVW_BREL:
7692     case elfcpp::R_ARM_THM_JUMP11:
7693     case elfcpp::R_ARM_THM_JUMP8:
7694       // We don't need to do anything for a relative addressing relocation
7695       // against a local symbol if it does not reference the GOT.
7696       break;
7697
7698     case elfcpp::R_ARM_GOTOFF32:
7699     case elfcpp::R_ARM_GOTOFF12:
7700       // We need a GOT section:
7701       target->got_section(symtab, layout);
7702       break;
7703
7704     case elfcpp::R_ARM_GOT_BREL:
7705     case elfcpp::R_ARM_GOT_PREL:
7706       {
7707         // The symbol requires a GOT entry.
7708         Arm_output_data_got<big_endian>* got =
7709           target->got_section(symtab, layout);
7710         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7711         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
7712           {
7713             // If we are generating a shared object, we need to add a
7714             // dynamic RELATIVE relocation for this symbol's GOT entry.
7715             if (parameters->options().output_is_position_independent())
7716               {
7717                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7718                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7719                 rel_dyn->add_local_relative(
7720                     object, r_sym, elfcpp::R_ARM_RELATIVE, got,
7721                     object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
7722               }
7723           }
7724       }
7725       break;
7726
7727     case elfcpp::R_ARM_TARGET1:
7728     case elfcpp::R_ARM_TARGET2:
7729       // This should have been mapped to another type already.
7730       // Fall through.
7731     case elfcpp::R_ARM_COPY:
7732     case elfcpp::R_ARM_GLOB_DAT:
7733     case elfcpp::R_ARM_JUMP_SLOT:
7734     case elfcpp::R_ARM_RELATIVE:
7735       // These are relocations which should only be seen by the
7736       // dynamic linker, and should never be seen here.
7737       gold_error(_("%s: unexpected reloc %u in object file"),
7738                  object->name().c_str(), r_type);
7739       break;
7740
7741
7742       // These are initial TLS relocs, which are expected when
7743       // linking.
7744     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
7745     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
7746     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
7747     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
7748     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
7749       {
7750         bool output_is_shared = parameters->options().shared();
7751         const tls::Tls_optimization optimized_type
7752             = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
7753                                                          r_type);
7754         switch (r_type)
7755           {
7756           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
7757             if (optimized_type == tls::TLSOPT_NONE)
7758               {
7759                 // Create a pair of GOT entries for the module index and
7760                 // dtv-relative offset.
7761                 Arm_output_data_got<big_endian>* got
7762                     = target->got_section(symtab, layout);
7763                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7764                 unsigned int shndx = lsym.get_st_shndx();
7765                 bool is_ordinary;
7766                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
7767                 if (!is_ordinary)
7768                   {
7769                     object->error(_("local symbol %u has bad shndx %u"),
7770                                   r_sym, shndx);
7771                     break;
7772                   }
7773
7774                 if (!parameters->doing_static_link())
7775                   got->add_local_pair_with_rel(object, r_sym, shndx,
7776                                                GOT_TYPE_TLS_PAIR,
7777                                                target->rel_dyn_section(layout),
7778                                                elfcpp::R_ARM_TLS_DTPMOD32, 0);
7779                 else
7780                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
7781                                                       object, r_sym);
7782               }
7783             else
7784               // FIXME: TLS optimization not supported yet.
7785               gold_unreachable();
7786             break;
7787
7788           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
7789             if (optimized_type == tls::TLSOPT_NONE)
7790               {
7791                 // Create a GOT entry for the module index.
7792                 target->got_mod_index_entry(symtab, layout, object);
7793               }
7794             else
7795               // FIXME: TLS optimization not supported yet.
7796               gold_unreachable();
7797             break;
7798
7799           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
7800             break;
7801
7802           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
7803             layout->set_has_static_tls();
7804             if (optimized_type == tls::TLSOPT_NONE)
7805               {
7806                 // Create a GOT entry for the tp-relative offset.
7807                 Arm_output_data_got<big_endian>* got
7808                   = target->got_section(symtab, layout);
7809                 unsigned int r_sym =
7810                    elfcpp::elf_r_sym<32>(reloc.get_r_info());
7811                 if (!parameters->doing_static_link())
7812                     got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
7813                                             target->rel_dyn_section(layout),
7814                                             elfcpp::R_ARM_TLS_TPOFF32);
7815                 else if (!object->local_has_got_offset(r_sym,
7816                                                        GOT_TYPE_TLS_OFFSET))
7817                   {
7818                     got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
7819                     unsigned int got_offset =
7820                       object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
7821                     got->add_static_reloc(got_offset,
7822                                           elfcpp::R_ARM_TLS_TPOFF32, object,
7823                                           r_sym);
7824                   }
7825               }
7826             else
7827               // FIXME: TLS optimization not supported yet.
7828               gold_unreachable();
7829             break;
7830
7831           case elfcpp::R_ARM_TLS_LE32:          // Local-exec
7832             layout->set_has_static_tls();
7833             if (output_is_shared)
7834               {
7835                 // We need to create a dynamic relocation.
7836                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
7837                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7838                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7839                 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
7840                                    output_section, data_shndx,
7841                                    reloc.get_r_offset());
7842               }
7843             break;
7844
7845           default:
7846             gold_unreachable();
7847           }
7848       }
7849       break;
7850
7851     case elfcpp::R_ARM_PC24:
7852     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7853     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7854     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7855     default:
7856       unsupported_reloc_local(object, r_type);
7857       break;
7858     }
7859 }
7860
7861 // Report an unsupported relocation against a global symbol.
7862
7863 template<bool big_endian>
7864 void
7865 Target_arm<big_endian>::Scan::unsupported_reloc_global(
7866     Sized_relobj<32, big_endian>* object,
7867     unsigned int r_type,
7868     Symbol* gsym)
7869 {
7870   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
7871              object->name().c_str(), r_type, gsym->demangled_name().c_str());
7872 }
7873
7874 template<bool big_endian>
7875 inline bool
7876 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
7877     unsigned int r_type)
7878 {
7879   switch (r_type)
7880     {
7881     case elfcpp::R_ARM_PC24:
7882     case elfcpp::R_ARM_THM_CALL:
7883     case elfcpp::R_ARM_PLT32:
7884     case elfcpp::R_ARM_CALL:
7885     case elfcpp::R_ARM_JUMP24:
7886     case elfcpp::R_ARM_THM_JUMP24:
7887     case elfcpp::R_ARM_SBREL31:
7888     case elfcpp::R_ARM_PREL31:
7889     case elfcpp::R_ARM_THM_JUMP19:
7890     case elfcpp::R_ARM_THM_JUMP6:
7891     case elfcpp::R_ARM_THM_JUMP11:
7892     case elfcpp::R_ARM_THM_JUMP8:
7893       // All the relocations above are branches except SBREL31 and PREL31.
7894       return false;
7895
7896     default:
7897       // Be conservative and assume this is a function pointer.
7898       return true;
7899     }
7900 }
7901
7902 template<bool big_endian>
7903 inline bool
7904 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
7905   Symbol_table*,
7906   Layout*,
7907   Target_arm<big_endian>* target,
7908   Sized_relobj<32, big_endian>*,
7909   unsigned int,
7910   Output_section*,
7911   const elfcpp::Rel<32, big_endian>&,
7912   unsigned int r_type,
7913   const elfcpp::Sym<32, big_endian>&)
7914 {
7915   r_type = target->get_real_reloc_type(r_type);
7916   return possible_function_pointer_reloc(r_type);
7917 }
7918
7919 template<bool big_endian>
7920 inline bool
7921 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
7922   Symbol_table*,
7923   Layout*,
7924   Target_arm<big_endian>* target,
7925   Sized_relobj<32, big_endian>*,
7926   unsigned int,
7927   Output_section*,
7928   const elfcpp::Rel<32, big_endian>&,
7929   unsigned int r_type,
7930   Symbol* gsym)
7931 {
7932   // GOT is not a function.
7933   if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
7934     return false;
7935
7936   r_type = target->get_real_reloc_type(r_type);
7937   return possible_function_pointer_reloc(r_type);
7938 }
7939
7940 // Scan a relocation for a global symbol.
7941
7942 template<bool big_endian>
7943 inline void
7944 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
7945                                      Layout* layout,
7946                                      Target_arm* target,
7947                                      Sized_relobj<32, big_endian>* object,
7948                                      unsigned int data_shndx,
7949                                      Output_section* output_section,
7950                                      const elfcpp::Rel<32, big_endian>& reloc,
7951                                      unsigned int r_type,
7952                                      Symbol* gsym)
7953 {
7954   // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
7955   // section.  We check here to avoid creating a dynamic reloc against
7956   // _GLOBAL_OFFSET_TABLE_.
7957   if (!target->has_got_section()
7958       && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
7959     target->got_section(symtab, layout);
7960
7961   r_type = get_real_reloc_type(r_type);
7962   switch (r_type)
7963     {
7964     case elfcpp::R_ARM_NONE:
7965     case elfcpp::R_ARM_V4BX:
7966     case elfcpp::R_ARM_GNU_VTENTRY:
7967     case elfcpp::R_ARM_GNU_VTINHERIT:
7968       break;
7969
7970     case elfcpp::R_ARM_ABS32:
7971     case elfcpp::R_ARM_ABS16:
7972     case elfcpp::R_ARM_ABS12:
7973     case elfcpp::R_ARM_THM_ABS5:
7974     case elfcpp::R_ARM_ABS8:
7975     case elfcpp::R_ARM_BASE_ABS:
7976     case elfcpp::R_ARM_MOVW_ABS_NC:
7977     case elfcpp::R_ARM_MOVT_ABS:
7978     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7979     case elfcpp::R_ARM_THM_MOVT_ABS:
7980     case elfcpp::R_ARM_ABS32_NOI:
7981       // Absolute addressing relocations.
7982       {
7983         // Make a PLT entry if necessary.
7984         if (this->symbol_needs_plt_entry(gsym))
7985           {
7986             target->make_plt_entry(symtab, layout, gsym);
7987             // Since this is not a PC-relative relocation, we may be
7988             // taking the address of a function. In that case we need to
7989             // set the entry in the dynamic symbol table to the address of
7990             // the PLT entry.
7991             if (gsym->is_from_dynobj() && !parameters->options().shared())
7992               gsym->set_needs_dynsym_value();
7993           }
7994         // Make a dynamic relocation if necessary.
7995         if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
7996           {
7997             if (gsym->may_need_copy_reloc())
7998               {
7999                 target->copy_reloc(symtab, layout, object,
8000                                    data_shndx, output_section, gsym, reloc);
8001               }
8002             else if ((r_type == elfcpp::R_ARM_ABS32
8003                       || r_type == elfcpp::R_ARM_ABS32_NOI)
8004                      && gsym->can_use_relative_reloc(false))
8005               {
8006                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8007                 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8008                                              output_section, object,
8009                                              data_shndx, reloc.get_r_offset());
8010               }
8011             else
8012               {
8013                 check_non_pic(object, r_type);
8014                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8015                 rel_dyn->add_global(gsym, r_type, output_section, object,
8016                                     data_shndx, reloc.get_r_offset());
8017               }
8018           }
8019       }
8020       break;
8021
8022     case elfcpp::R_ARM_GOTOFF32:
8023     case elfcpp::R_ARM_GOTOFF12:
8024       // We need a GOT section.
8025       target->got_section(symtab, layout);
8026       break;
8027       
8028     case elfcpp::R_ARM_REL32:
8029     case elfcpp::R_ARM_LDR_PC_G0:
8030     case elfcpp::R_ARM_SBREL32:
8031     case elfcpp::R_ARM_THM_PC8:
8032     case elfcpp::R_ARM_BASE_PREL:
8033     case elfcpp::R_ARM_MOVW_PREL_NC:
8034     case elfcpp::R_ARM_MOVT_PREL:
8035     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8036     case elfcpp::R_ARM_THM_MOVT_PREL:
8037     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8038     case elfcpp::R_ARM_THM_PC12:
8039     case elfcpp::R_ARM_REL32_NOI:
8040     case elfcpp::R_ARM_ALU_PC_G0_NC:
8041     case elfcpp::R_ARM_ALU_PC_G0:
8042     case elfcpp::R_ARM_ALU_PC_G1_NC:
8043     case elfcpp::R_ARM_ALU_PC_G1:
8044     case elfcpp::R_ARM_ALU_PC_G2:
8045     case elfcpp::R_ARM_LDR_PC_G1:
8046     case elfcpp::R_ARM_LDR_PC_G2:
8047     case elfcpp::R_ARM_LDRS_PC_G0:
8048     case elfcpp::R_ARM_LDRS_PC_G1:
8049     case elfcpp::R_ARM_LDRS_PC_G2:
8050     case elfcpp::R_ARM_LDC_PC_G0:
8051     case elfcpp::R_ARM_LDC_PC_G1:
8052     case elfcpp::R_ARM_LDC_PC_G2:
8053     case elfcpp::R_ARM_ALU_SB_G0_NC:
8054     case elfcpp::R_ARM_ALU_SB_G0:
8055     case elfcpp::R_ARM_ALU_SB_G1_NC:
8056     case elfcpp::R_ARM_ALU_SB_G1:
8057     case elfcpp::R_ARM_ALU_SB_G2:
8058     case elfcpp::R_ARM_LDR_SB_G0:
8059     case elfcpp::R_ARM_LDR_SB_G1:
8060     case elfcpp::R_ARM_LDR_SB_G2:
8061     case elfcpp::R_ARM_LDRS_SB_G0:
8062     case elfcpp::R_ARM_LDRS_SB_G1:
8063     case elfcpp::R_ARM_LDRS_SB_G2:
8064     case elfcpp::R_ARM_LDC_SB_G0:
8065     case elfcpp::R_ARM_LDC_SB_G1:
8066     case elfcpp::R_ARM_LDC_SB_G2:
8067     case elfcpp::R_ARM_MOVW_BREL_NC:
8068     case elfcpp::R_ARM_MOVT_BREL:
8069     case elfcpp::R_ARM_MOVW_BREL:
8070     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8071     case elfcpp::R_ARM_THM_MOVT_BREL:
8072     case elfcpp::R_ARM_THM_MOVW_BREL:
8073       // Relative addressing relocations.
8074       {
8075         // Make a dynamic relocation if necessary.
8076         int flags = Symbol::NON_PIC_REF;
8077         if (gsym->needs_dynamic_reloc(flags))
8078           {
8079             if (target->may_need_copy_reloc(gsym))
8080               {
8081                 target->copy_reloc(symtab, layout, object,
8082                                    data_shndx, output_section, gsym, reloc);
8083               }
8084             else
8085               {
8086                 check_non_pic(object, r_type);
8087                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8088                 rel_dyn->add_global(gsym, r_type, output_section, object,
8089                                     data_shndx, reloc.get_r_offset());
8090               }
8091           }
8092       }
8093       break;
8094
8095     case elfcpp::R_ARM_THM_CALL:
8096     case elfcpp::R_ARM_PLT32:
8097     case elfcpp::R_ARM_CALL:
8098     case elfcpp::R_ARM_JUMP24:
8099     case elfcpp::R_ARM_THM_JUMP24:
8100     case elfcpp::R_ARM_SBREL31:
8101     case elfcpp::R_ARM_PREL31:
8102     case elfcpp::R_ARM_THM_JUMP19:
8103     case elfcpp::R_ARM_THM_JUMP6:
8104     case elfcpp::R_ARM_THM_JUMP11:
8105     case elfcpp::R_ARM_THM_JUMP8:
8106       // All the relocation above are branches except for the PREL31 ones.
8107       // A PREL31 relocation can point to a personality function in a shared
8108       // library.  In that case we want to use a PLT because we want to
8109       // call the personality routine and the dyanmic linkers we care about
8110       // do not support dynamic PREL31 relocations. An REL31 relocation may
8111       // point to a function whose unwinding behaviour is being described but
8112       // we will not mistakenly generate a PLT for that because we should use
8113       // a local section symbol.
8114
8115       // If the symbol is fully resolved, this is just a relative
8116       // local reloc.  Otherwise we need a PLT entry.
8117       if (gsym->final_value_is_known())
8118         break;
8119       // If building a shared library, we can also skip the PLT entry
8120       // if the symbol is defined in the output file and is protected
8121       // or hidden.
8122       if (gsym->is_defined()
8123           && !gsym->is_from_dynobj()
8124           && !gsym->is_preemptible())
8125         break;
8126       target->make_plt_entry(symtab, layout, gsym);
8127       break;
8128
8129     case elfcpp::R_ARM_GOT_BREL:
8130     case elfcpp::R_ARM_GOT_ABS:
8131     case elfcpp::R_ARM_GOT_PREL:
8132       {
8133         // The symbol requires a GOT entry.
8134         Arm_output_data_got<big_endian>* got =
8135           target->got_section(symtab, layout);
8136         if (gsym->final_value_is_known())
8137           got->add_global(gsym, GOT_TYPE_STANDARD);
8138         else
8139           {
8140             // If this symbol is not fully resolved, we need to add a
8141             // GOT entry with a dynamic relocation.
8142             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8143             if (gsym->is_from_dynobj()
8144                 || gsym->is_undefined()
8145                 || gsym->is_preemptible())
8146               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8147                                        rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8148             else
8149               {
8150                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
8151                   rel_dyn->add_global_relative(
8152                       gsym, elfcpp::R_ARM_RELATIVE, got,
8153                       gsym->got_offset(GOT_TYPE_STANDARD));
8154               }
8155           }
8156       }
8157       break;
8158
8159     case elfcpp::R_ARM_TARGET1:
8160     case elfcpp::R_ARM_TARGET2:
8161       // These should have been mapped to other types already.
8162       // Fall through.
8163     case elfcpp::R_ARM_COPY:
8164     case elfcpp::R_ARM_GLOB_DAT:
8165     case elfcpp::R_ARM_JUMP_SLOT:
8166     case elfcpp::R_ARM_RELATIVE:
8167       // These are relocations which should only be seen by the
8168       // dynamic linker, and should never be seen here.
8169       gold_error(_("%s: unexpected reloc %u in object file"),
8170                  object->name().c_str(), r_type);
8171       break;
8172
8173       // These are initial tls relocs, which are expected when
8174       // linking.
8175     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8176     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8177     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8178     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8179     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8180       {
8181         const bool is_final = gsym->final_value_is_known();
8182         const tls::Tls_optimization optimized_type
8183             = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8184         switch (r_type)
8185           {
8186           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8187             if (optimized_type == tls::TLSOPT_NONE)
8188               {
8189                 // Create a pair of GOT entries for the module index and
8190                 // dtv-relative offset.
8191                 Arm_output_data_got<big_endian>* got
8192                     = target->got_section(symtab, layout);
8193                 if (!parameters->doing_static_link())
8194                   got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8195                                                 target->rel_dyn_section(layout),
8196                                                 elfcpp::R_ARM_TLS_DTPMOD32,
8197                                                 elfcpp::R_ARM_TLS_DTPOFF32);
8198                 else
8199                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8200               }
8201             else
8202               // FIXME: TLS optimization not supported yet.
8203               gold_unreachable();
8204             break;
8205
8206           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
8207             if (optimized_type == tls::TLSOPT_NONE)
8208               {
8209                 // Create a GOT entry for the module index.
8210                 target->got_mod_index_entry(symtab, layout, object);
8211               }
8212             else
8213               // FIXME: TLS optimization not supported yet.
8214               gold_unreachable();
8215             break;
8216
8217           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
8218             break;
8219
8220           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
8221             layout->set_has_static_tls();
8222             if (optimized_type == tls::TLSOPT_NONE)
8223               {
8224                 // Create a GOT entry for the tp-relative offset.
8225                 Arm_output_data_got<big_endian>* got
8226                   = target->got_section(symtab, layout);
8227                 if (!parameters->doing_static_link())
8228                   got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
8229                                            target->rel_dyn_section(layout),
8230                                            elfcpp::R_ARM_TLS_TPOFF32);
8231                 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
8232                   {
8233                     got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
8234                     unsigned int got_offset =
8235                        gsym->got_offset(GOT_TYPE_TLS_OFFSET);
8236                     got->add_static_reloc(got_offset,
8237                                           elfcpp::R_ARM_TLS_TPOFF32, gsym);
8238                   }
8239               }
8240             else
8241               // FIXME: TLS optimization not supported yet.
8242               gold_unreachable();
8243             break;
8244
8245           case elfcpp::R_ARM_TLS_LE32:  // Local-exec
8246             layout->set_has_static_tls();
8247             if (parameters->options().shared())
8248               {
8249                 // We need to create a dynamic relocation.
8250                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8251                 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
8252                                     output_section, object,
8253                                     data_shndx, reloc.get_r_offset());
8254               }
8255             break;
8256
8257           default:
8258             gold_unreachable();
8259           }
8260       }
8261       break;
8262
8263     case elfcpp::R_ARM_PC24:
8264     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8265     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8266     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8267     default:
8268       unsupported_reloc_global(object, r_type, gsym);
8269       break;
8270     }
8271 }
8272
8273 // Process relocations for gc.
8274
8275 template<bool big_endian>
8276 void
8277 Target_arm<big_endian>::gc_process_relocs(Symbol_table* symtab,
8278                                           Layout* layout,
8279                                           Sized_relobj<32, big_endian>* object,
8280                                           unsigned int data_shndx,
8281                                           unsigned int,
8282                                           const unsigned char* prelocs,
8283                                           size_t reloc_count,
8284                                           Output_section* output_section,
8285                                           bool needs_special_offset_handling,
8286                                           size_t local_symbol_count,
8287                                           const unsigned char* plocal_symbols)
8288 {
8289   typedef Target_arm<big_endian> Arm;
8290   typedef typename Target_arm<big_endian>::Scan Scan;
8291
8292   gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
8293                           typename Target_arm::Relocatable_size_for_reloc>(
8294     symtab,
8295     layout,
8296     this,
8297     object,
8298     data_shndx,
8299     prelocs,
8300     reloc_count,
8301     output_section,
8302     needs_special_offset_handling,
8303     local_symbol_count,
8304     plocal_symbols);
8305 }
8306
8307 // Scan relocations for a section.
8308
8309 template<bool big_endian>
8310 void
8311 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
8312                                     Layout* layout,
8313                                     Sized_relobj<32, big_endian>* object,
8314                                     unsigned int data_shndx,
8315                                     unsigned int sh_type,
8316                                     const unsigned char* prelocs,
8317                                     size_t reloc_count,
8318                                     Output_section* output_section,
8319                                     bool needs_special_offset_handling,
8320                                     size_t local_symbol_count,
8321                                     const unsigned char* plocal_symbols)
8322 {
8323   typedef typename Target_arm<big_endian>::Scan Scan;
8324   if (sh_type == elfcpp::SHT_RELA)
8325     {
8326       gold_error(_("%s: unsupported RELA reloc section"),
8327                  object->name().c_str());
8328       return;
8329     }
8330
8331   gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
8332     symtab,
8333     layout,
8334     this,
8335     object,
8336     data_shndx,
8337     prelocs,
8338     reloc_count,
8339     output_section,
8340     needs_special_offset_handling,
8341     local_symbol_count,
8342     plocal_symbols);
8343 }
8344
8345 // Finalize the sections.
8346
8347 template<bool big_endian>
8348 void
8349 Target_arm<big_endian>::do_finalize_sections(
8350     Layout* layout,
8351     const Input_objects* input_objects,
8352     Symbol_table* symtab)
8353 {
8354   bool merged_any_attributes = false;
8355   // Merge processor-specific flags.
8356   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
8357        p != input_objects->relobj_end();
8358        ++p)
8359     {
8360       Arm_relobj<big_endian>* arm_relobj =
8361         Arm_relobj<big_endian>::as_arm_relobj(*p);
8362       if (arm_relobj->merge_flags_and_attributes())
8363         {
8364           this->merge_processor_specific_flags(
8365               arm_relobj->name(),
8366               arm_relobj->processor_specific_flags());
8367           this->merge_object_attributes(arm_relobj->name().c_str(),
8368                                         arm_relobj->attributes_section_data());
8369           merged_any_attributes = true;
8370         }
8371     } 
8372
8373   for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
8374        p != input_objects->dynobj_end();
8375        ++p)
8376     {
8377       Arm_dynobj<big_endian>* arm_dynobj =
8378         Arm_dynobj<big_endian>::as_arm_dynobj(*p);
8379       this->merge_processor_specific_flags(
8380           arm_dynobj->name(),
8381           arm_dynobj->processor_specific_flags());
8382       this->merge_object_attributes(arm_dynobj->name().c_str(),
8383                                     arm_dynobj->attributes_section_data());
8384       merged_any_attributes = true;
8385     }
8386
8387   // Create an empty uninitialized attribute section if we still don't have it
8388   // at this moment.  This happens if there is no attributes sections in all
8389   // inputs.
8390   if (this->attributes_section_data_ == NULL)
8391     this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
8392
8393   // Check BLX use.
8394   const Object_attribute* cpu_arch_attr =
8395     this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
8396   if (cpu_arch_attr->int_value() > elfcpp::TAG_CPU_ARCH_V4)
8397     this->set_may_use_blx(true);
8398  
8399   // Check if we need to use Cortex-A8 workaround.
8400   if (parameters->options().user_set_fix_cortex_a8())
8401     this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
8402   else
8403     {
8404       // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
8405       // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
8406       // profile.  
8407       const Object_attribute* cpu_arch_profile_attr =
8408         this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
8409       this->fix_cortex_a8_ =
8410         (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
8411          && (cpu_arch_profile_attr->int_value() == 'A'
8412              || cpu_arch_profile_attr->int_value() == 0));
8413     }
8414   
8415   // Check if we can use V4BX interworking.
8416   // The V4BX interworking stub contains BX instruction,
8417   // which is not specified for some profiles.
8418   if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
8419       && !this->may_use_blx())
8420     gold_error(_("unable to provide V4BX reloc interworking fix up; "
8421                  "the target profile does not support BX instruction"));
8422
8423   // Fill in some more dynamic tags.
8424   const Reloc_section* rel_plt = (this->plt_ == NULL
8425                                   ? NULL
8426                                   : this->plt_->rel_plt());
8427   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
8428                                   this->rel_dyn_, true, false);
8429
8430   // Emit any relocs we saved in an attempt to avoid generating COPY
8431   // relocs.
8432   if (this->copy_relocs_.any_saved_relocs())
8433     this->copy_relocs_.emit(this->rel_dyn_section(layout));
8434
8435   // Handle the .ARM.exidx section.
8436   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8437
8438   if (!parameters->options().relocatable())
8439     {
8440       if (exidx_section != NULL
8441           && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
8442         {
8443           // Create __exidx_start and __exdix_end symbols.
8444           symtab->define_in_output_data("__exidx_start", NULL,
8445                                         Symbol_table::PREDEFINED,
8446                                         exidx_section, 0, 0, elfcpp::STT_OBJECT,
8447                                         elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
8448                                         0, false, true);
8449           symtab->define_in_output_data("__exidx_end", NULL,
8450                                         Symbol_table::PREDEFINED,
8451                                         exidx_section, 0, 0, elfcpp::STT_OBJECT,
8452                                         elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
8453                                         0, true, true);
8454
8455           // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8456           // the .ARM.exidx section.
8457           if (!layout->script_options()->saw_phdrs_clause())
8458             {
8459               gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
8460                                                       0)
8461                           == NULL);
8462               Output_segment*  exidx_segment =
8463                 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8464               exidx_segment->add_output_section_to_nonload(exidx_section,
8465                                                            elfcpp::PF_R);
8466             }
8467         }
8468       else
8469         {
8470           symtab->define_as_constant("__exidx_start", NULL,
8471                                      Symbol_table::PREDEFINED,
8472                                      0, 0, elfcpp::STT_OBJECT,
8473                                      elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8474                                      true, false);
8475           symtab->define_as_constant("__exidx_end", NULL,
8476                                      Symbol_table::PREDEFINED,
8477                                      0, 0, elfcpp::STT_OBJECT,
8478                                      elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8479                                      true, false);
8480         }
8481     }
8482
8483   // Create an .ARM.attributes section if we have merged any attributes
8484   // from inputs.
8485   if (merged_any_attributes)
8486     {
8487       Output_attributes_section_data* attributes_section =
8488       new Output_attributes_section_data(*this->attributes_section_data_);
8489       layout->add_output_section_data(".ARM.attributes",
8490                                       elfcpp::SHT_ARM_ATTRIBUTES, 0,
8491                                       attributes_section, ORDER_INVALID,
8492                                       false);
8493     }
8494
8495   // Fix up links in section EXIDX headers.
8496   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
8497        p != layout->section_list().end();
8498        ++p)
8499     if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
8500       {
8501         Arm_output_section<big_endian>* os =
8502           Arm_output_section<big_endian>::as_arm_output_section(*p);
8503         os->set_exidx_section_link();
8504       }
8505 }
8506
8507 // Return whether a direct absolute static relocation needs to be applied.
8508 // In cases where Scan::local() or Scan::global() has created
8509 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8510 // of the relocation is carried in the data, and we must not
8511 // apply the static relocation.
8512
8513 template<bool big_endian>
8514 inline bool
8515 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8516     const Sized_symbol<32>* gsym,
8517     int ref_flags,
8518     bool is_32bit,
8519     Output_section* output_section)
8520 {
8521   // If the output section is not allocated, then we didn't call
8522   // scan_relocs, we didn't create a dynamic reloc, and we must apply
8523   // the reloc here.
8524   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8525       return true;
8526
8527   // For local symbols, we will have created a non-RELATIVE dynamic
8528   // relocation only if (a) the output is position independent,
8529   // (b) the relocation is absolute (not pc- or segment-relative), and
8530   // (c) the relocation is not 32 bits wide.
8531   if (gsym == NULL)
8532     return !(parameters->options().output_is_position_independent()
8533              && (ref_flags & Symbol::ABSOLUTE_REF)
8534              && !is_32bit);
8535
8536   // For global symbols, we use the same helper routines used in the
8537   // scan pass.  If we did not create a dynamic relocation, or if we
8538   // created a RELATIVE dynamic relocation, we should apply the static
8539   // relocation.
8540   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8541   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8542                  && gsym->can_use_relative_reloc(ref_flags
8543                                                  & Symbol::FUNCTION_CALL);
8544   return !has_dyn || is_rel;
8545 }
8546
8547 // Perform a relocation.
8548
8549 template<bool big_endian>
8550 inline bool
8551 Target_arm<big_endian>::Relocate::relocate(
8552     const Relocate_info<32, big_endian>* relinfo,
8553     Target_arm* target,
8554     Output_section* output_section,
8555     size_t relnum,
8556     const elfcpp::Rel<32, big_endian>& rel,
8557     unsigned int r_type,
8558     const Sized_symbol<32>* gsym,
8559     const Symbol_value<32>* psymval,
8560     unsigned char* view,
8561     Arm_address address,
8562     section_size_type view_size)
8563 {
8564   typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8565
8566   r_type = get_real_reloc_type(r_type);
8567   const Arm_reloc_property* reloc_property =
8568     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8569   if (reloc_property == NULL)
8570     {
8571       std::string reloc_name =
8572         arm_reloc_property_table->reloc_name_in_error_message(r_type);
8573       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8574                              _("cannot relocate %s in object file"),
8575                              reloc_name.c_str());
8576       return true;
8577     }
8578
8579   const Arm_relobj<big_endian>* object =
8580     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8581
8582   // If the final branch target of a relocation is THUMB instruction, this
8583   // is 1.  Otherwise it is 0.
8584   Arm_address thumb_bit = 0;
8585   Symbol_value<32> symval;
8586   bool is_weakly_undefined_without_plt = false;
8587   bool have_got_offset = false;
8588   unsigned int got_offset = 0;
8589
8590   // If the relocation uses the GOT entry of a symbol instead of the symbol
8591   // itself, we don't care about whether the symbol is defined or what kind
8592   // of symbol it is.
8593   if (reloc_property->uses_got_entry())
8594     {
8595       // Get the GOT offset.
8596       // The GOT pointer points to the end of the GOT section.
8597       // We need to subtract the size of the GOT section to get
8598       // the actual offset to use in the relocation.
8599       // TODO: We should move GOT offset computing code in TLS relocations
8600       // to here.
8601       switch (r_type)
8602         {
8603         case elfcpp::R_ARM_GOT_BREL:
8604         case elfcpp::R_ARM_GOT_PREL:
8605           if (gsym != NULL)
8606             {
8607               gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8608               got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8609                             - target->got_size());
8610             }
8611           else
8612             {
8613               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8614               gold_assert(object->local_has_got_offset(r_sym,
8615                                                        GOT_TYPE_STANDARD));
8616               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8617                             - target->got_size());
8618             }
8619           have_got_offset = true;
8620           break;
8621
8622         default:
8623           break;
8624         }
8625     }
8626   else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8627     {
8628       if (gsym != NULL)
8629         {
8630           // This is a global symbol.  Determine if we use PLT and if the
8631           // final target is THUMB.
8632           if (gsym->use_plt_offset(reloc_is_non_pic(r_type)))
8633             {
8634               // This uses a PLT, change the symbol value.
8635               symval.set_output_value(target->plt_section()->address()
8636                                       + gsym->plt_offset());
8637               psymval = &symval;
8638             }
8639           else if (gsym->is_weak_undefined())
8640             {
8641               // This is a weakly undefined symbol and we do not use PLT
8642               // for this relocation.  A branch targeting this symbol will
8643               // be converted into an NOP.
8644               is_weakly_undefined_without_plt = true;
8645             }
8646           else if (gsym->is_undefined() && reloc_property->uses_symbol())
8647             {
8648               // This relocation uses the symbol value but the symbol is
8649               // undefined.  Exit early and have the caller reporting an
8650               // error.
8651               return true;
8652             }
8653           else
8654             {
8655               // Set thumb bit if symbol:
8656               // -Has type STT_ARM_TFUNC or
8657               // -Has type STT_FUNC, is defined and with LSB in value set.
8658               thumb_bit =
8659                 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8660                  || (gsym->type() == elfcpp::STT_FUNC
8661                      && !gsym->is_undefined()
8662                      && ((psymval->value(object, 0) & 1) != 0)))
8663                 ? 1
8664                 : 0);
8665             }
8666         }
8667       else
8668         {
8669           // This is a local symbol.  Determine if the final target is THUMB.
8670           // We saved this information when all the local symbols were read.
8671           elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8672           unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8673           thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8674         }
8675     }
8676   else
8677     {
8678       // This is a fake relocation synthesized for a stub.  It does not have
8679       // a real symbol.  We just look at the LSB of the symbol value to
8680       // determine if the target is THUMB or not.
8681       thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8682     }
8683
8684   // Strip LSB if this points to a THUMB target.
8685   if (thumb_bit != 0
8686       && reloc_property->uses_thumb_bit() 
8687       && ((psymval->value(object, 0) & 1) != 0))
8688     {
8689       Arm_address stripped_value =
8690         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8691       symval.set_output_value(stripped_value);
8692       psymval = &symval;
8693     } 
8694
8695   // To look up relocation stubs, we need to pass the symbol table index of
8696   // a local symbol.
8697   unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8698
8699   // Get the addressing origin of the output segment defining the
8700   // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8701   Arm_address sym_origin = 0;
8702   if (reloc_property->uses_symbol_base())
8703     {
8704       if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8705         // R_ARM_BASE_ABS with the NULL symbol will give the
8706         // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8707         // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8708         sym_origin = target->got_plt_section()->address();
8709       else if (gsym == NULL)
8710         sym_origin = 0;
8711       else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8712         sym_origin = gsym->output_segment()->vaddr();
8713       else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
8714         sym_origin = gsym->output_data()->address();
8715
8716       // TODO: Assumes the segment base to be zero for the global symbols
8717       // till the proper support for the segment-base-relative addressing
8718       // will be implemented.  This is consistent with GNU ld.
8719     }
8720
8721   // For relative addressing relocation, find out the relative address base.
8722   Arm_address relative_address_base = 0;
8723   switch(reloc_property->relative_address_base())
8724     {
8725     case Arm_reloc_property::RAB_NONE:
8726     // Relocations with relative address bases RAB_TLS and RAB_tp are
8727     // handled by relocate_tls.  So we do not need to do anything here.
8728     case Arm_reloc_property::RAB_TLS:
8729     case Arm_reloc_property::RAB_tp:
8730       break;
8731     case Arm_reloc_property::RAB_B_S:
8732       relative_address_base = sym_origin;
8733       break;
8734     case Arm_reloc_property::RAB_GOT_ORG:
8735       relative_address_base = target->got_plt_section()->address();
8736       break;
8737     case Arm_reloc_property::RAB_P:
8738       relative_address_base = address;
8739       break;
8740     case Arm_reloc_property::RAB_Pa:
8741       relative_address_base = address & 0xfffffffcU;
8742       break;
8743     default:
8744       gold_unreachable(); 
8745     }
8746     
8747   typename Arm_relocate_functions::Status reloc_status =
8748         Arm_relocate_functions::STATUS_OKAY;
8749   bool check_overflow = reloc_property->checks_overflow();
8750   switch (r_type)
8751     {
8752     case elfcpp::R_ARM_NONE:
8753       break;
8754
8755     case elfcpp::R_ARM_ABS8:
8756       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8757                                     output_section))
8758         reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
8759       break;
8760
8761     case elfcpp::R_ARM_ABS12:
8762       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8763                                     output_section))
8764         reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
8765       break;
8766
8767     case elfcpp::R_ARM_ABS16:
8768       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8769                                     output_section))
8770         reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
8771       break;
8772
8773     case elfcpp::R_ARM_ABS32:
8774       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
8775                                     output_section))
8776         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8777                                                      thumb_bit);
8778       break;
8779
8780     case elfcpp::R_ARM_ABS32_NOI:
8781       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
8782                                     output_section))
8783         // No thumb bit for this relocation: (S + A)
8784         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8785                                                      0);
8786       break;
8787
8788     case elfcpp::R_ARM_MOVW_ABS_NC:
8789       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8790                                     output_section))
8791         reloc_status = Arm_relocate_functions::movw(view, object, psymval,
8792                                                     0, thumb_bit,
8793                                                     check_overflow);
8794       break;
8795
8796     case elfcpp::R_ARM_MOVT_ABS:
8797       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8798                                     output_section))
8799         reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
8800       break;
8801
8802     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8803       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8804                                     output_section))
8805         reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
8806                                                         0, thumb_bit, false);
8807       break;
8808
8809     case elfcpp::R_ARM_THM_MOVT_ABS:
8810       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8811                                     output_section))
8812         reloc_status = Arm_relocate_functions::thm_movt(view, object,
8813                                                         psymval, 0);
8814       break;
8815
8816     case elfcpp::R_ARM_MOVW_PREL_NC:
8817     case elfcpp::R_ARM_MOVW_BREL_NC:
8818     case elfcpp::R_ARM_MOVW_BREL:
8819       reloc_status =
8820         Arm_relocate_functions::movw(view, object, psymval,
8821                                      relative_address_base, thumb_bit,
8822                                      check_overflow);
8823       break;
8824
8825     case elfcpp::R_ARM_MOVT_PREL:
8826     case elfcpp::R_ARM_MOVT_BREL:
8827       reloc_status =
8828         Arm_relocate_functions::movt(view, object, psymval,
8829                                      relative_address_base);
8830       break;
8831
8832     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8833     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8834     case elfcpp::R_ARM_THM_MOVW_BREL:
8835       reloc_status =
8836         Arm_relocate_functions::thm_movw(view, object, psymval,
8837                                          relative_address_base,
8838                                          thumb_bit, check_overflow);
8839       break;
8840
8841     case elfcpp::R_ARM_THM_MOVT_PREL:
8842     case elfcpp::R_ARM_THM_MOVT_BREL:
8843       reloc_status =
8844         Arm_relocate_functions::thm_movt(view, object, psymval,
8845                                          relative_address_base);
8846       break;
8847         
8848     case elfcpp::R_ARM_REL32:
8849       reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
8850                                                    address, thumb_bit);
8851       break;
8852
8853     case elfcpp::R_ARM_THM_ABS5:
8854       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8855                                     output_section))
8856         reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
8857       break;
8858
8859     // Thumb long branches.
8860     case elfcpp::R_ARM_THM_CALL:
8861     case elfcpp::R_ARM_THM_XPC22:
8862     case elfcpp::R_ARM_THM_JUMP24:
8863       reloc_status =
8864         Arm_relocate_functions::thumb_branch_common(
8865             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
8866             thumb_bit, is_weakly_undefined_without_plt);
8867       break;
8868
8869     case elfcpp::R_ARM_GOTOFF32:
8870       {
8871         Arm_address got_origin;
8872         got_origin = target->got_plt_section()->address();
8873         reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
8874                                                      got_origin, thumb_bit);
8875       }
8876       break;
8877
8878     case elfcpp::R_ARM_BASE_PREL:
8879       gold_assert(gsym != NULL);
8880       reloc_status =
8881           Arm_relocate_functions::base_prel(view, sym_origin, address);
8882       break;
8883
8884     case elfcpp::R_ARM_BASE_ABS:
8885       {
8886         if (!should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8887                                       output_section))
8888           break;
8889
8890         reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
8891       }
8892       break;
8893
8894     case elfcpp::R_ARM_GOT_BREL:
8895       gold_assert(have_got_offset);
8896       reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
8897       break;
8898
8899     case elfcpp::R_ARM_GOT_PREL:
8900       gold_assert(have_got_offset);
8901       // Get the address origin for GOT PLT, which is allocated right
8902       // after the GOT section, to calculate an absolute address of
8903       // the symbol GOT entry (got_origin + got_offset).
8904       Arm_address got_origin;
8905       got_origin = target->got_plt_section()->address();
8906       reloc_status = Arm_relocate_functions::got_prel(view,
8907                                                       got_origin + got_offset,
8908                                                       address);
8909       break;
8910
8911     case elfcpp::R_ARM_PLT32:
8912     case elfcpp::R_ARM_CALL:
8913     case elfcpp::R_ARM_JUMP24:
8914     case elfcpp::R_ARM_XPC25:
8915       gold_assert(gsym == NULL
8916                   || gsym->has_plt_offset()
8917                   || gsym->final_value_is_known()
8918                   || (gsym->is_defined()
8919                       && !gsym->is_from_dynobj()
8920                       && !gsym->is_preemptible()));
8921       reloc_status =
8922         Arm_relocate_functions::arm_branch_common(
8923             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
8924             thumb_bit, is_weakly_undefined_without_plt);
8925       break;
8926
8927     case elfcpp::R_ARM_THM_JUMP19:
8928       reloc_status =
8929         Arm_relocate_functions::thm_jump19(view, object, psymval, address,
8930                                            thumb_bit);
8931       break;
8932
8933     case elfcpp::R_ARM_THM_JUMP6:
8934       reloc_status =
8935         Arm_relocate_functions::thm_jump6(view, object, psymval, address);
8936       break;
8937
8938     case elfcpp::R_ARM_THM_JUMP8:
8939       reloc_status =
8940         Arm_relocate_functions::thm_jump8(view, object, psymval, address);
8941       break;
8942
8943     case elfcpp::R_ARM_THM_JUMP11:
8944       reloc_status =
8945         Arm_relocate_functions::thm_jump11(view, object, psymval, address);
8946       break;
8947
8948     case elfcpp::R_ARM_PREL31:
8949       reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
8950                                                     address, thumb_bit);
8951       break;
8952
8953     case elfcpp::R_ARM_V4BX:
8954       if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
8955         {
8956           const bool is_v4bx_interworking =
8957               (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
8958           reloc_status =
8959             Arm_relocate_functions::v4bx(relinfo, view, object, address,
8960                                          is_v4bx_interworking);
8961         }
8962       break;
8963
8964     case elfcpp::R_ARM_THM_PC8:
8965       reloc_status =
8966         Arm_relocate_functions::thm_pc8(view, object, psymval, address);
8967       break;
8968
8969     case elfcpp::R_ARM_THM_PC12:
8970       reloc_status =
8971         Arm_relocate_functions::thm_pc12(view, object, psymval, address);
8972       break;
8973
8974     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8975       reloc_status =
8976         Arm_relocate_functions::thm_alu11(view, object, psymval, address,
8977                                           thumb_bit);
8978       break;
8979
8980     case elfcpp::R_ARM_ALU_PC_G0_NC:
8981     case elfcpp::R_ARM_ALU_PC_G0:
8982     case elfcpp::R_ARM_ALU_PC_G1_NC:
8983     case elfcpp::R_ARM_ALU_PC_G1:
8984     case elfcpp::R_ARM_ALU_PC_G2:
8985     case elfcpp::R_ARM_ALU_SB_G0_NC:
8986     case elfcpp::R_ARM_ALU_SB_G0:
8987     case elfcpp::R_ARM_ALU_SB_G1_NC:
8988     case elfcpp::R_ARM_ALU_SB_G1:
8989     case elfcpp::R_ARM_ALU_SB_G2:
8990       reloc_status =
8991         Arm_relocate_functions::arm_grp_alu(view, object, psymval,
8992                                             reloc_property->group_index(),
8993                                             relative_address_base,
8994                                             thumb_bit, check_overflow);
8995       break;
8996
8997     case elfcpp::R_ARM_LDR_PC_G0:
8998     case elfcpp::R_ARM_LDR_PC_G1:
8999     case elfcpp::R_ARM_LDR_PC_G2:
9000     case elfcpp::R_ARM_LDR_SB_G0:
9001     case elfcpp::R_ARM_LDR_SB_G1:
9002     case elfcpp::R_ARM_LDR_SB_G2:
9003       reloc_status =
9004           Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9005                                               reloc_property->group_index(),
9006                                               relative_address_base);
9007       break;
9008
9009     case elfcpp::R_ARM_LDRS_PC_G0:
9010     case elfcpp::R_ARM_LDRS_PC_G1:
9011     case elfcpp::R_ARM_LDRS_PC_G2:
9012     case elfcpp::R_ARM_LDRS_SB_G0:
9013     case elfcpp::R_ARM_LDRS_SB_G1:
9014     case elfcpp::R_ARM_LDRS_SB_G2:
9015       reloc_status =
9016           Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9017                                                reloc_property->group_index(),
9018                                                relative_address_base);
9019       break;
9020
9021     case elfcpp::R_ARM_LDC_PC_G0:
9022     case elfcpp::R_ARM_LDC_PC_G1:
9023     case elfcpp::R_ARM_LDC_PC_G2:
9024     case elfcpp::R_ARM_LDC_SB_G0:
9025     case elfcpp::R_ARM_LDC_SB_G1:
9026     case elfcpp::R_ARM_LDC_SB_G2:
9027       reloc_status =
9028           Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9029                                               reloc_property->group_index(),
9030                                               relative_address_base);
9031       break;
9032
9033       // These are initial tls relocs, which are expected when
9034       // linking.
9035     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9036     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9037     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9038     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9039     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9040       reloc_status =
9041         this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9042                            view, address, view_size);
9043       break;
9044
9045     // The known and unknown unsupported and/or deprecated relocations.
9046     case elfcpp::R_ARM_PC24:
9047     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9048     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9049     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9050     default:
9051       // Just silently leave the method. We should get an appropriate error
9052       // message in the scan methods.
9053       break;
9054     }
9055
9056   // Report any errors.
9057   switch (reloc_status)
9058     {
9059     case Arm_relocate_functions::STATUS_OKAY:
9060       break;
9061     case Arm_relocate_functions::STATUS_OVERFLOW:
9062       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9063                              _("relocation overflow in %s"),
9064                              reloc_property->name().c_str());
9065       break;
9066     case Arm_relocate_functions::STATUS_BAD_RELOC:
9067       gold_error_at_location(
9068         relinfo,
9069         relnum,
9070         rel.get_r_offset(),
9071         _("unexpected opcode while processing relocation %s"),
9072         reloc_property->name().c_str());
9073       break;
9074     default:
9075       gold_unreachable();
9076     }
9077
9078   return true;
9079 }
9080
9081 // Perform a TLS relocation.
9082
9083 template<bool big_endian>
9084 inline typename Arm_relocate_functions<big_endian>::Status
9085 Target_arm<big_endian>::Relocate::relocate_tls(
9086     const Relocate_info<32, big_endian>* relinfo,
9087     Target_arm<big_endian>* target,
9088     size_t relnum,
9089     const elfcpp::Rel<32, big_endian>& rel,
9090     unsigned int r_type,
9091     const Sized_symbol<32>* gsym,
9092     const Symbol_value<32>* psymval,
9093     unsigned char* view,
9094     elfcpp::Elf_types<32>::Elf_Addr address,
9095     section_size_type /*view_size*/ )
9096 {
9097   typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9098   typedef Relocate_functions<32, big_endian> RelocFuncs;
9099   Output_segment* tls_segment = relinfo->layout->tls_segment();
9100
9101   const Sized_relobj<32, big_endian>* object = relinfo->object;
9102
9103   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9104
9105   const bool is_final = (gsym == NULL
9106                          ? !parameters->options().shared()
9107                          : gsym->final_value_is_known());
9108   const tls::Tls_optimization optimized_type
9109       = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9110   switch (r_type)
9111     {
9112     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9113         {
9114           unsigned int got_type = GOT_TYPE_TLS_PAIR;
9115           unsigned int got_offset;
9116           if (gsym != NULL)
9117             {
9118               gold_assert(gsym->has_got_offset(got_type));
9119               got_offset = gsym->got_offset(got_type) - target->got_size();
9120             }
9121           else
9122             {
9123               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9124               gold_assert(object->local_has_got_offset(r_sym, got_type));
9125               got_offset = (object->local_got_offset(r_sym, got_type)
9126                             - target->got_size());
9127             }
9128           if (optimized_type == tls::TLSOPT_NONE)
9129             {
9130               Arm_address got_entry =
9131                 target->got_plt_section()->address() + got_offset;
9132               
9133               // Relocate the field with the PC relative offset of the pair of
9134               // GOT entries.
9135               RelocFuncs::pcrel32(view, got_entry, address);
9136               return ArmRelocFuncs::STATUS_OKAY;
9137             }
9138         }
9139       break;
9140
9141     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9142       if (optimized_type == tls::TLSOPT_NONE)
9143         {
9144           // Relocate the field with the offset of the GOT entry for
9145           // the module index.
9146           unsigned int got_offset;
9147           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9148                         - target->got_size());
9149           Arm_address got_entry =
9150             target->got_plt_section()->address() + got_offset;
9151
9152           // Relocate the field with the PC relative offset of the pair of
9153           // GOT entries.
9154           RelocFuncs::pcrel32(view, got_entry, address);
9155           return ArmRelocFuncs::STATUS_OKAY;
9156         }
9157       break;
9158
9159     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9160       RelocFuncs::rel32(view, value);
9161       return ArmRelocFuncs::STATUS_OKAY;
9162
9163     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9164       if (optimized_type == tls::TLSOPT_NONE)
9165         {
9166           // Relocate the field with the offset of the GOT entry for
9167           // the tp-relative offset of the symbol.
9168           unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9169           unsigned int got_offset;
9170           if (gsym != NULL)
9171             {
9172               gold_assert(gsym->has_got_offset(got_type));
9173               got_offset = gsym->got_offset(got_type);
9174             }
9175           else
9176             {
9177               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9178               gold_assert(object->local_has_got_offset(r_sym, got_type));
9179               got_offset = object->local_got_offset(r_sym, got_type);
9180             }
9181
9182           // All GOT offsets are relative to the end of the GOT.
9183           got_offset -= target->got_size();
9184
9185           Arm_address got_entry =
9186             target->got_plt_section()->address() + got_offset;
9187
9188           // Relocate the field with the PC relative offset of the GOT entry.
9189           RelocFuncs::pcrel32(view, got_entry, address);
9190           return ArmRelocFuncs::STATUS_OKAY;
9191         }
9192       break;
9193
9194     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9195       // If we're creating a shared library, a dynamic relocation will
9196       // have been created for this location, so do not apply it now.
9197       if (!parameters->options().shared())
9198         {
9199           gold_assert(tls_segment != NULL);
9200
9201           // $tp points to the TCB, which is followed by the TLS, so we
9202           // need to add TCB size to the offset.
9203           Arm_address aligned_tcb_size =
9204             align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9205           RelocFuncs::rel32(view, value + aligned_tcb_size);
9206
9207         }
9208       return ArmRelocFuncs::STATUS_OKAY;
9209     
9210     default:
9211       gold_unreachable();
9212     }
9213
9214   gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9215                          _("unsupported reloc %u"),
9216                          r_type);
9217   return ArmRelocFuncs::STATUS_BAD_RELOC;
9218 }
9219
9220 // Relocate section data.
9221
9222 template<bool big_endian>
9223 void
9224 Target_arm<big_endian>::relocate_section(
9225     const Relocate_info<32, big_endian>* relinfo,
9226     unsigned int sh_type,
9227     const unsigned char* prelocs,
9228     size_t reloc_count,
9229     Output_section* output_section,
9230     bool needs_special_offset_handling,
9231     unsigned char* view,
9232     Arm_address address,
9233     section_size_type view_size,
9234     const Reloc_symbol_changes* reloc_symbol_changes)
9235 {
9236   typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
9237   gold_assert(sh_type == elfcpp::SHT_REL);
9238
9239   // See if we are relocating a relaxed input section.  If so, the view
9240   // covers the whole output section and we need to adjust accordingly.
9241   if (needs_special_offset_handling)
9242     {
9243       const Output_relaxed_input_section* poris =
9244         output_section->find_relaxed_input_section(relinfo->object,
9245                                                    relinfo->data_shndx);
9246       if (poris != NULL)
9247         {
9248           Arm_address section_address = poris->address();
9249           section_size_type section_size = poris->data_size();
9250
9251           gold_assert((section_address >= address)
9252                       && ((section_address + section_size)
9253                           <= (address + view_size)));
9254
9255           off_t offset = section_address - address;
9256           view += offset;
9257           address += offset;
9258           view_size = section_size;
9259         }
9260     }
9261
9262   gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
9263                          Arm_relocate>(
9264     relinfo,
9265     this,
9266     prelocs,
9267     reloc_count,
9268     output_section,
9269     needs_special_offset_handling,
9270     view,
9271     address,
9272     view_size,
9273     reloc_symbol_changes);
9274 }
9275
9276 // Return the size of a relocation while scanning during a relocatable
9277 // link.
9278
9279 template<bool big_endian>
9280 unsigned int
9281 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
9282     unsigned int r_type,
9283     Relobj* object)
9284 {
9285   r_type = get_real_reloc_type(r_type);
9286   const Arm_reloc_property* arp =
9287       arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9288   if (arp != NULL)
9289     return arp->size();
9290   else
9291     {
9292       std::string reloc_name =
9293         arm_reloc_property_table->reloc_name_in_error_message(r_type);
9294       gold_error(_("%s: unexpected %s in object file"),
9295                  object->name().c_str(), reloc_name.c_str());
9296       return 0;
9297     }
9298 }
9299
9300 // Scan the relocs during a relocatable link.
9301
9302 template<bool big_endian>
9303 void
9304 Target_arm<big_endian>::scan_relocatable_relocs(
9305     Symbol_table* symtab,
9306     Layout* layout,
9307     Sized_relobj<32, big_endian>* object,
9308     unsigned int data_shndx,
9309     unsigned int sh_type,
9310     const unsigned char* prelocs,
9311     size_t reloc_count,
9312     Output_section* output_section,
9313     bool needs_special_offset_handling,
9314     size_t local_symbol_count,
9315     const unsigned char* plocal_symbols,
9316     Relocatable_relocs* rr)
9317 {
9318   gold_assert(sh_type == elfcpp::SHT_REL);
9319
9320   typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
9321     Relocatable_size_for_reloc> Scan_relocatable_relocs;
9322
9323   gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
9324       Scan_relocatable_relocs>(
9325     symtab,
9326     layout,
9327     object,
9328     data_shndx,
9329     prelocs,
9330     reloc_count,
9331     output_section,
9332     needs_special_offset_handling,
9333     local_symbol_count,
9334     plocal_symbols,
9335     rr);
9336 }
9337
9338 // Relocate a section during a relocatable link.
9339
9340 template<bool big_endian>
9341 void
9342 Target_arm<big_endian>::relocate_for_relocatable(
9343     const Relocate_info<32, big_endian>* relinfo,
9344     unsigned int sh_type,
9345     const unsigned char* prelocs,
9346     size_t reloc_count,
9347     Output_section* output_section,
9348     off_t offset_in_output_section,
9349     const Relocatable_relocs* rr,
9350     unsigned char* view,
9351     Arm_address view_address,
9352     section_size_type view_size,
9353     unsigned char* reloc_view,
9354     section_size_type reloc_view_size)
9355 {
9356   gold_assert(sh_type == elfcpp::SHT_REL);
9357
9358   gold::relocate_for_relocatable<32, big_endian, elfcpp::SHT_REL>(
9359     relinfo,
9360     prelocs,
9361     reloc_count,
9362     output_section,
9363     offset_in_output_section,
9364     rr,
9365     view,
9366     view_address,
9367     view_size,
9368     reloc_view,
9369     reloc_view_size);
9370 }
9371
9372 // Perform target-specific processing in a relocatable link.  This is
9373 // only used if we use the relocation strategy RELOC_SPECIAL.
9374
9375 template<bool big_endian>
9376 void
9377 Target_arm<big_endian>::relocate_special_relocatable(
9378     const Relocate_info<32, big_endian>* relinfo,
9379     unsigned int sh_type,
9380     const unsigned char* preloc_in,
9381     size_t relnum,
9382     Output_section* output_section,
9383     off_t offset_in_output_section,
9384     unsigned char* view,
9385     elfcpp::Elf_types<32>::Elf_Addr view_address,
9386     section_size_type,
9387     unsigned char* preloc_out)
9388 {
9389   // We can only handle REL type relocation sections.
9390   gold_assert(sh_type == elfcpp::SHT_REL);
9391
9392   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
9393   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
9394     Reltype_write;
9395   const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
9396
9397   const Arm_relobj<big_endian>* object =
9398     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9399   const unsigned int local_count = object->local_symbol_count();
9400
9401   Reltype reloc(preloc_in);
9402   Reltype_write reloc_write(preloc_out);
9403
9404   elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
9405   const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9406   const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
9407
9408   const Arm_reloc_property* arp =
9409     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9410   gold_assert(arp != NULL);
9411
9412   // Get the new symbol index.
9413   // We only use RELOC_SPECIAL strategy in local relocations.
9414   gold_assert(r_sym < local_count);
9415
9416   // We are adjusting a section symbol.  We need to find
9417   // the symbol table index of the section symbol for
9418   // the output section corresponding to input section
9419   // in which this symbol is defined.
9420   bool is_ordinary;
9421   unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
9422   gold_assert(is_ordinary);
9423   Output_section* os = object->output_section(shndx);
9424   gold_assert(os != NULL);
9425   gold_assert(os->needs_symtab_index());
9426   unsigned int new_symndx = os->symtab_index();
9427
9428   // Get the new offset--the location in the output section where
9429   // this relocation should be applied.
9430
9431   Arm_address offset = reloc.get_r_offset();
9432   Arm_address new_offset;
9433   if (offset_in_output_section != invalid_address)
9434     new_offset = offset + offset_in_output_section;
9435   else
9436     {
9437       section_offset_type sot_offset =
9438           convert_types<section_offset_type, Arm_address>(offset);
9439       section_offset_type new_sot_offset =
9440           output_section->output_offset(object, relinfo->data_shndx,
9441                                         sot_offset);
9442       gold_assert(new_sot_offset != -1);
9443       new_offset = new_sot_offset;
9444     }
9445
9446   // In an object file, r_offset is an offset within the section.
9447   // In an executable or dynamic object, generated by
9448   // --emit-relocs, r_offset is an absolute address.
9449   if (!parameters->options().relocatable())
9450     {
9451       new_offset += view_address;
9452       if (offset_in_output_section != invalid_address)
9453         new_offset -= offset_in_output_section;
9454     }
9455
9456   reloc_write.put_r_offset(new_offset);
9457   reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
9458
9459   // Handle the reloc addend.
9460   // The relocation uses a section symbol in the input file.
9461   // We are adjusting it to use a section symbol in the output
9462   // file.  The input section symbol refers to some address in
9463   // the input section.  We need the relocation in the output
9464   // file to refer to that same address.  This adjustment to
9465   // the addend is the same calculation we use for a simple
9466   // absolute relocation for the input section symbol.
9467
9468   const Symbol_value<32>* psymval = object->local_symbol(r_sym);
9469
9470   // Handle THUMB bit.
9471   Symbol_value<32> symval;
9472   Arm_address thumb_bit =
9473      object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9474   if (thumb_bit != 0
9475       && arp->uses_thumb_bit() 
9476       && ((psymval->value(object, 0) & 1) != 0))
9477     {
9478       Arm_address stripped_value =
9479         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9480       symval.set_output_value(stripped_value);
9481       psymval = &symval;
9482     } 
9483
9484   unsigned char* paddend = view + offset;
9485   typename Arm_relocate_functions<big_endian>::Status reloc_status =
9486         Arm_relocate_functions<big_endian>::STATUS_OKAY;
9487   switch (r_type)
9488     {
9489     case elfcpp::R_ARM_ABS8:
9490       reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
9491                                                               psymval);
9492       break;
9493
9494     case elfcpp::R_ARM_ABS12:
9495       reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
9496                                                                psymval);
9497       break;
9498
9499     case elfcpp::R_ARM_ABS16:
9500       reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
9501                                                                psymval);
9502       break;
9503
9504     case elfcpp::R_ARM_THM_ABS5:
9505       reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
9506                                                                   object,
9507                                                                   psymval);
9508       break;
9509
9510     case elfcpp::R_ARM_MOVW_ABS_NC:
9511     case elfcpp::R_ARM_MOVW_PREL_NC:
9512     case elfcpp::R_ARM_MOVW_BREL_NC:
9513     case elfcpp::R_ARM_MOVW_BREL:
9514       reloc_status = Arm_relocate_functions<big_endian>::movw(
9515           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9516       break;
9517
9518     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9519     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9520     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9521     case elfcpp::R_ARM_THM_MOVW_BREL:
9522       reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
9523           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9524       break;
9525
9526     case elfcpp::R_ARM_THM_CALL:
9527     case elfcpp::R_ARM_THM_XPC22:
9528     case elfcpp::R_ARM_THM_JUMP24:
9529       reloc_status =
9530         Arm_relocate_functions<big_endian>::thumb_branch_common(
9531             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9532             false);
9533       break;
9534
9535     case elfcpp::R_ARM_PLT32:
9536     case elfcpp::R_ARM_CALL:
9537     case elfcpp::R_ARM_JUMP24:
9538     case elfcpp::R_ARM_XPC25:
9539       reloc_status =
9540         Arm_relocate_functions<big_endian>::arm_branch_common(
9541             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9542             false);
9543       break;
9544
9545     case elfcpp::R_ARM_THM_JUMP19:
9546       reloc_status =
9547         Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
9548                                                        psymval, 0, thumb_bit);
9549       break;
9550
9551     case elfcpp::R_ARM_THM_JUMP6:
9552       reloc_status =
9553         Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
9554                                                       0);
9555       break;
9556
9557     case elfcpp::R_ARM_THM_JUMP8:
9558       reloc_status =
9559         Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
9560                                                       0);
9561       break;
9562
9563     case elfcpp::R_ARM_THM_JUMP11:
9564       reloc_status =
9565         Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
9566                                                        0);
9567       break;
9568
9569     case elfcpp::R_ARM_PREL31:
9570       reloc_status =
9571         Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
9572                                                    thumb_bit);
9573       break;
9574
9575     case elfcpp::R_ARM_THM_PC8:
9576       reloc_status =
9577         Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
9578                                                     0);
9579       break;
9580
9581     case elfcpp::R_ARM_THM_PC12:
9582       reloc_status =
9583         Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
9584                                                      0);
9585       break;
9586
9587     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9588       reloc_status =
9589         Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
9590                                                       0, thumb_bit);
9591       break;
9592
9593     // These relocation truncate relocation results so we cannot handle them
9594     // in a relocatable link.
9595     case elfcpp::R_ARM_MOVT_ABS:
9596     case elfcpp::R_ARM_THM_MOVT_ABS:
9597     case elfcpp::R_ARM_MOVT_PREL:
9598     case elfcpp::R_ARM_MOVT_BREL:
9599     case elfcpp::R_ARM_THM_MOVT_PREL:
9600     case elfcpp::R_ARM_THM_MOVT_BREL:
9601     case elfcpp::R_ARM_ALU_PC_G0_NC:
9602     case elfcpp::R_ARM_ALU_PC_G0:
9603     case elfcpp::R_ARM_ALU_PC_G1_NC:
9604     case elfcpp::R_ARM_ALU_PC_G1:
9605     case elfcpp::R_ARM_ALU_PC_G2:
9606     case elfcpp::R_ARM_ALU_SB_G0_NC:
9607     case elfcpp::R_ARM_ALU_SB_G0:
9608     case elfcpp::R_ARM_ALU_SB_G1_NC:
9609     case elfcpp::R_ARM_ALU_SB_G1:
9610     case elfcpp::R_ARM_ALU_SB_G2:
9611     case elfcpp::R_ARM_LDR_PC_G0:
9612     case elfcpp::R_ARM_LDR_PC_G1:
9613     case elfcpp::R_ARM_LDR_PC_G2:
9614     case elfcpp::R_ARM_LDR_SB_G0:
9615     case elfcpp::R_ARM_LDR_SB_G1:
9616     case elfcpp::R_ARM_LDR_SB_G2:
9617     case elfcpp::R_ARM_LDRS_PC_G0:
9618     case elfcpp::R_ARM_LDRS_PC_G1:
9619     case elfcpp::R_ARM_LDRS_PC_G2:
9620     case elfcpp::R_ARM_LDRS_SB_G0:
9621     case elfcpp::R_ARM_LDRS_SB_G1:
9622     case elfcpp::R_ARM_LDRS_SB_G2:
9623     case elfcpp::R_ARM_LDC_PC_G0:
9624     case elfcpp::R_ARM_LDC_PC_G1:
9625     case elfcpp::R_ARM_LDC_PC_G2:
9626     case elfcpp::R_ARM_LDC_SB_G0:
9627     case elfcpp::R_ARM_LDC_SB_G1:
9628     case elfcpp::R_ARM_LDC_SB_G2:
9629       gold_error(_("cannot handle %s in a relocatable link"),
9630                  arp->name().c_str());
9631       break;
9632
9633     default:
9634       gold_unreachable();
9635     }
9636
9637   // Report any errors.
9638   switch (reloc_status)
9639     {
9640     case Arm_relocate_functions<big_endian>::STATUS_OKAY:
9641       break;
9642     case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
9643       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9644                              _("relocation overflow in %s"),
9645                              arp->name().c_str());
9646       break;
9647     case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
9648       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9649         _("unexpected opcode while processing relocation %s"),
9650         arp->name().c_str());
9651       break;
9652     default:
9653       gold_unreachable();
9654     }
9655 }
9656
9657 // Return the value to use for a dynamic symbol which requires special
9658 // treatment.  This is how we support equality comparisons of function
9659 // pointers across shared library boundaries, as described in the
9660 // processor specific ABI supplement.
9661
9662 template<bool big_endian>
9663 uint64_t
9664 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
9665 {
9666   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
9667   return this->plt_section()->address() + gsym->plt_offset();
9668 }
9669
9670 // Map platform-specific relocs to real relocs
9671 //
9672 template<bool big_endian>
9673 unsigned int
9674 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
9675 {
9676   switch (r_type)
9677     {
9678     case elfcpp::R_ARM_TARGET1:
9679       // This is either R_ARM_ABS32 or R_ARM_REL32;
9680       return elfcpp::R_ARM_ABS32;
9681
9682     case elfcpp::R_ARM_TARGET2:
9683       // This can be any reloc type but ususally is R_ARM_GOT_PREL
9684       return elfcpp::R_ARM_GOT_PREL;
9685
9686     default:
9687       return r_type;
9688     }
9689 }
9690
9691 // Whether if two EABI versions V1 and V2 are compatible.
9692
9693 template<bool big_endian>
9694 bool
9695 Target_arm<big_endian>::are_eabi_versions_compatible(
9696     elfcpp::Elf_Word v1,
9697     elfcpp::Elf_Word v2)
9698 {
9699   // v4 and v5 are the same spec before and after it was released,
9700   // so allow mixing them.
9701   if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
9702       || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
9703       || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
9704     return true;
9705
9706   return v1 == v2;
9707 }
9708
9709 // Combine FLAGS from an input object called NAME and the processor-specific
9710 // flags in the ELF header of the output.  Much of this is adapted from the
9711 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
9712 // in bfd/elf32-arm.c.
9713
9714 template<bool big_endian>
9715 void
9716 Target_arm<big_endian>::merge_processor_specific_flags(
9717     const std::string& name,
9718     elfcpp::Elf_Word flags)
9719 {
9720   if (this->are_processor_specific_flags_set())
9721     {
9722       elfcpp::Elf_Word out_flags = this->processor_specific_flags();
9723
9724       // Nothing to merge if flags equal to those in output.
9725       if (flags == out_flags)
9726         return;
9727
9728       // Complain about various flag mismatches.
9729       elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
9730       elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
9731       if (!this->are_eabi_versions_compatible(version1, version2)
9732           && parameters->options().warn_mismatch())
9733         gold_error(_("Source object %s has EABI version %d but output has "
9734                      "EABI version %d."),
9735                    name.c_str(),
9736                    (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
9737                    (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
9738     }
9739   else
9740     {
9741       // If the input is the default architecture and had the default
9742       // flags then do not bother setting the flags for the output
9743       // architecture, instead allow future merges to do this.  If no
9744       // future merges ever set these flags then they will retain their
9745       // uninitialised values, which surprise surprise, correspond
9746       // to the default values.
9747       if (flags == 0)
9748         return;
9749
9750       // This is the first time, just copy the flags.
9751       // We only copy the EABI version for now.
9752       this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
9753     }
9754 }
9755
9756 // Adjust ELF file header.
9757 template<bool big_endian>
9758 void
9759 Target_arm<big_endian>::do_adjust_elf_header(
9760     unsigned char* view,
9761     int len) const
9762 {
9763   gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
9764
9765   elfcpp::Ehdr<32, big_endian> ehdr(view);
9766   unsigned char e_ident[elfcpp::EI_NIDENT];
9767   memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
9768
9769   if (elfcpp::arm_eabi_version(this->processor_specific_flags())
9770       == elfcpp::EF_ARM_EABI_UNKNOWN)
9771     e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
9772   else
9773     e_ident[elfcpp::EI_OSABI] = 0;
9774   e_ident[elfcpp::EI_ABIVERSION] = 0;
9775
9776   // FIXME: Do EF_ARM_BE8 adjustment.
9777
9778   elfcpp::Ehdr_write<32, big_endian> oehdr(view);
9779   oehdr.put_e_ident(e_ident);
9780 }
9781
9782 // do_make_elf_object to override the same function in the base class.
9783 // We need to use a target-specific sub-class of Sized_relobj<32, big_endian>
9784 // to store ARM specific information.  Hence we need to have our own
9785 // ELF object creation.
9786
9787 template<bool big_endian>
9788 Object*
9789 Target_arm<big_endian>::do_make_elf_object(
9790     const std::string& name,
9791     Input_file* input_file,
9792     off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
9793 {
9794   int et = ehdr.get_e_type();
9795   if (et == elfcpp::ET_REL)
9796     {
9797       Arm_relobj<big_endian>* obj =
9798         new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
9799       obj->setup();
9800       return obj;
9801     }
9802   else if (et == elfcpp::ET_DYN)
9803     {
9804       Sized_dynobj<32, big_endian>* obj =
9805         new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
9806       obj->setup();
9807       return obj;
9808     }
9809   else
9810     {
9811       gold_error(_("%s: unsupported ELF file type %d"),
9812                  name.c_str(), et);
9813       return NULL;
9814     }
9815 }
9816
9817 // Read the architecture from the Tag_also_compatible_with attribute, if any.
9818 // Returns -1 if no architecture could be read.
9819 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
9820
9821 template<bool big_endian>
9822 int
9823 Target_arm<big_endian>::get_secondary_compatible_arch(
9824     const Attributes_section_data* pasd)
9825 {
9826   const Object_attribute* known_attributes =
9827     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
9828
9829   // Note: the tag and its argument below are uleb128 values, though
9830   // currently-defined values fit in one byte for each.
9831   const std::string& sv =
9832     known_attributes[elfcpp::Tag_also_compatible_with].string_value();
9833   if (sv.size() == 2
9834       && sv.data()[0] == elfcpp::Tag_CPU_arch
9835       && (sv.data()[1] & 128) != 128)
9836    return sv.data()[1];
9837
9838   // This tag is "safely ignorable", so don't complain if it looks funny.
9839   return -1;
9840 }
9841
9842 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
9843 // The tag is removed if ARCH is -1.
9844 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
9845
9846 template<bool big_endian>
9847 void
9848 Target_arm<big_endian>::set_secondary_compatible_arch(
9849     Attributes_section_data* pasd,
9850     int arch)
9851 {
9852   Object_attribute* known_attributes =
9853     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
9854
9855   if (arch == -1)
9856     {
9857       known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
9858       return;
9859     }
9860
9861   // Note: the tag and its argument below are uleb128 values, though
9862   // currently-defined values fit in one byte for each.
9863   char sv[3];
9864   sv[0] = elfcpp::Tag_CPU_arch;
9865   gold_assert(arch != 0);
9866   sv[1] = arch;
9867   sv[2] = '\0';
9868
9869   known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
9870 }
9871
9872 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
9873 // into account.
9874 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
9875
9876 template<bool big_endian>
9877 int
9878 Target_arm<big_endian>::tag_cpu_arch_combine(
9879     const char* name,
9880     int oldtag,
9881     int* secondary_compat_out,
9882     int newtag,
9883     int secondary_compat)
9884 {
9885 #define T(X) elfcpp::TAG_CPU_ARCH_##X
9886   static const int v6t2[] =
9887     {
9888       T(V6T2),   // PRE_V4.
9889       T(V6T2),   // V4.
9890       T(V6T2),   // V4T.
9891       T(V6T2),   // V5T.
9892       T(V6T2),   // V5TE.
9893       T(V6T2),   // V5TEJ.
9894       T(V6T2),   // V6.
9895       T(V7),     // V6KZ.
9896       T(V6T2)    // V6T2.
9897     };
9898   static const int v6k[] =
9899     {
9900       T(V6K),    // PRE_V4.
9901       T(V6K),    // V4.
9902       T(V6K),    // V4T.
9903       T(V6K),    // V5T.
9904       T(V6K),    // V5TE.
9905       T(V6K),    // V5TEJ.
9906       T(V6K),    // V6.
9907       T(V6KZ),   // V6KZ.
9908       T(V7),     // V6T2.
9909       T(V6K)     // V6K.
9910     };
9911   static const int v7[] =
9912     {
9913       T(V7),     // PRE_V4.
9914       T(V7),     // V4.
9915       T(V7),     // V4T.
9916       T(V7),     // V5T.
9917       T(V7),     // V5TE.
9918       T(V7),     // V5TEJ.
9919       T(V7),     // V6.
9920       T(V7),     // V6KZ.
9921       T(V7),     // V6T2.
9922       T(V7),     // V6K.
9923       T(V7)      // V7.
9924     };
9925   static const int v6_m[] =
9926     {
9927       -1,        // PRE_V4.
9928       -1,        // V4.
9929       T(V6K),    // V4T.
9930       T(V6K),    // V5T.
9931       T(V6K),    // V5TE.
9932       T(V6K),    // V5TEJ.
9933       T(V6K),    // V6.
9934       T(V6KZ),   // V6KZ.
9935       T(V7),     // V6T2.
9936       T(V6K),    // V6K.
9937       T(V7),     // V7.
9938       T(V6_M)    // V6_M.
9939     };
9940   static const int v6s_m[] =
9941     {
9942       -1,        // PRE_V4.
9943       -1,        // V4.
9944       T(V6K),    // V4T.
9945       T(V6K),    // V5T.
9946       T(V6K),    // V5TE.
9947       T(V6K),    // V5TEJ.
9948       T(V6K),    // V6.
9949       T(V6KZ),   // V6KZ.
9950       T(V7),     // V6T2.
9951       T(V6K),    // V6K.
9952       T(V7),     // V7.
9953       T(V6S_M),  // V6_M.
9954       T(V6S_M)   // V6S_M.
9955     };
9956   static const int v7e_m[] =
9957     {
9958       -1,       // PRE_V4.
9959       -1,       // V4.
9960       T(V7E_M), // V4T.
9961       T(V7E_M), // V5T.
9962       T(V7E_M), // V5TE.
9963       T(V7E_M), // V5TEJ.
9964       T(V7E_M), // V6.
9965       T(V7E_M), // V6KZ.
9966       T(V7E_M), // V6T2.
9967       T(V7E_M), // V6K.
9968       T(V7E_M), // V7.
9969       T(V7E_M), // V6_M.
9970       T(V7E_M), // V6S_M.
9971       T(V7E_M)  // V7E_M.
9972     };
9973   static const int v4t_plus_v6_m[] =
9974     {
9975       -1,               // PRE_V4.
9976       -1,               // V4.
9977       T(V4T),           // V4T.
9978       T(V5T),           // V5T.
9979       T(V5TE),          // V5TE.
9980       T(V5TEJ),         // V5TEJ.
9981       T(V6),            // V6.
9982       T(V6KZ),          // V6KZ.
9983       T(V6T2),          // V6T2.
9984       T(V6K),           // V6K.
9985       T(V7),            // V7.
9986       T(V6_M),          // V6_M.
9987       T(V6S_M),         // V6S_M.
9988       T(V7E_M),         // V7E_M.
9989       T(V4T_PLUS_V6_M)  // V4T plus V6_M.
9990     };
9991   static const int* comb[] =
9992     {
9993       v6t2,
9994       v6k,
9995       v7,
9996       v6_m,
9997       v6s_m,
9998       v7e_m,
9999       // Pseudo-architecture.
10000       v4t_plus_v6_m
10001     };
10002
10003   // Check we've not got a higher architecture than we know about.
10004
10005   if (oldtag >= elfcpp::MAX_TAG_CPU_ARCH || newtag >= elfcpp::MAX_TAG_CPU_ARCH)
10006     {
10007       gold_error(_("%s: unknown CPU architecture"), name);
10008       return -1;
10009     }
10010
10011   // Override old tag if we have a Tag_also_compatible_with on the output.
10012
10013   if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10014       || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10015     oldtag = T(V4T_PLUS_V6_M);
10016
10017   // And override the new tag if we have a Tag_also_compatible_with on the
10018   // input.
10019
10020   if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10021       || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10022     newtag = T(V4T_PLUS_V6_M);
10023
10024   // Architectures before V6KZ add features monotonically.
10025   int tagh = std::max(oldtag, newtag);
10026   if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10027     return tagh;
10028
10029   int tagl = std::min(oldtag, newtag);
10030   int result = comb[tagh - T(V6T2)][tagl];
10031
10032   // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10033   // as the canonical version.
10034   if (result == T(V4T_PLUS_V6_M))
10035     {
10036       result = T(V4T);
10037       *secondary_compat_out = T(V6_M);
10038     }
10039   else
10040     *secondary_compat_out = -1;
10041
10042   if (result == -1)
10043     {
10044       gold_error(_("%s: conflicting CPU architectures %d/%d"),
10045                  name, oldtag, newtag);
10046       return -1;
10047     }
10048
10049   return result;
10050 #undef T
10051 }
10052
10053 // Helper to print AEABI enum tag value.
10054
10055 template<bool big_endian>
10056 std::string
10057 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10058 {
10059   static const char* aeabi_enum_names[] =
10060     { "", "variable-size", "32-bit", "" };
10061   const size_t aeabi_enum_names_size =
10062     sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10063
10064   if (value < aeabi_enum_names_size)
10065     return std::string(aeabi_enum_names[value]);
10066   else
10067     {
10068       char buffer[100];
10069       sprintf(buffer, "<unknown value %u>", value);
10070       return std::string(buffer);
10071     }
10072 }
10073
10074 // Return the string value to store in TAG_CPU_name.
10075
10076 template<bool big_endian>
10077 std::string
10078 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10079 {
10080   static const char* name_table[] = {
10081     // These aren't real CPU names, but we can't guess
10082     // that from the architecture version alone.
10083    "Pre v4",
10084    "ARM v4",
10085    "ARM v4T",
10086    "ARM v5T",
10087    "ARM v5TE",
10088    "ARM v5TEJ",
10089    "ARM v6",
10090    "ARM v6KZ",
10091    "ARM v6T2",
10092    "ARM v6K",
10093    "ARM v7",
10094    "ARM v6-M",
10095    "ARM v6S-M",
10096    "ARM v7E-M"
10097  };
10098  const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10099
10100   if (value < name_table_size)
10101     return std::string(name_table[value]);
10102   else
10103     {
10104       char buffer[100];
10105       sprintf(buffer, "<unknown CPU value %u>", value);
10106       return std::string(buffer);
10107     } 
10108 }
10109
10110 // Merge object attributes from input file called NAME with those of the
10111 // output.  The input object attributes are in the object pointed by PASD.
10112
10113 template<bool big_endian>
10114 void
10115 Target_arm<big_endian>::merge_object_attributes(
10116     const char* name,
10117     const Attributes_section_data* pasd)
10118 {
10119   // Return if there is no attributes section data.
10120   if (pasd == NULL)
10121     return;
10122
10123   // If output has no object attributes, just copy.
10124   const int vendor = Object_attribute::OBJ_ATTR_PROC;
10125   if (this->attributes_section_data_ == NULL)
10126     {
10127       this->attributes_section_data_ = new Attributes_section_data(*pasd);
10128       Object_attribute* out_attr =
10129         this->attributes_section_data_->known_attributes(vendor);
10130
10131       // We do not output objects with Tag_MPextension_use_legacy - we move
10132       //  the attribute's value to Tag_MPextension_use.  */
10133       if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10134         {
10135           if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10136               && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10137                 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10138             {
10139               gold_error(_("%s has both the current and legacy "
10140                            "Tag_MPextension_use attributes"),
10141                          name);
10142             }
10143
10144           out_attr[elfcpp::Tag_MPextension_use] =
10145             out_attr[elfcpp::Tag_MPextension_use_legacy];
10146           out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10147           out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10148         }
10149
10150       return;
10151     }
10152
10153   const Object_attribute* in_attr = pasd->known_attributes(vendor);
10154   Object_attribute* out_attr =
10155     this->attributes_section_data_->known_attributes(vendor);
10156
10157   // This needs to happen before Tag_ABI_FP_number_model is merged.  */
10158   if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10159       != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
10160     {
10161       // Ignore mismatches if the object doesn't use floating point.  */
10162       if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
10163         out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10164             in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10165       else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
10166                && parameters->options().warn_mismatch())
10167         gold_error(_("%s uses VFP register arguments, output does not"),
10168                    name);
10169     }
10170
10171   for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10172     {
10173       // Merge this attribute with existing attributes.
10174       switch (i)
10175         {
10176         case elfcpp::Tag_CPU_raw_name:
10177         case elfcpp::Tag_CPU_name:
10178           // These are merged after Tag_CPU_arch.
10179           break;
10180
10181         case elfcpp::Tag_ABI_optimization_goals:
10182         case elfcpp::Tag_ABI_FP_optimization_goals:
10183           // Use the first value seen.
10184           break;
10185
10186         case elfcpp::Tag_CPU_arch:
10187           {
10188             unsigned int saved_out_attr = out_attr->int_value();
10189             // Merge Tag_CPU_arch and Tag_also_compatible_with.
10190             int secondary_compat =
10191               this->get_secondary_compatible_arch(pasd);
10192             int secondary_compat_out =
10193               this->get_secondary_compatible_arch(
10194                   this->attributes_section_data_);
10195             out_attr[i].set_int_value(
10196                 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10197                                      &secondary_compat_out,
10198                                      in_attr[i].int_value(),
10199                                      secondary_compat));
10200             this->set_secondary_compatible_arch(this->attributes_section_data_,
10201                                                 secondary_compat_out);
10202
10203             // Merge Tag_CPU_name and Tag_CPU_raw_name.
10204             if (out_attr[i].int_value() == saved_out_attr)
10205               ; // Leave the names alone.
10206             else if (out_attr[i].int_value() == in_attr[i].int_value())
10207               {
10208                 // The output architecture has been changed to match the
10209                 // input architecture.  Use the input names.
10210                 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10211                     in_attr[elfcpp::Tag_CPU_name].string_value());
10212                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10213                     in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10214               }
10215             else
10216               {
10217                 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10218                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10219               }
10220
10221             // If we still don't have a value for Tag_CPU_name,
10222             // make one up now.  Tag_CPU_raw_name remains blank.
10223             if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10224               {
10225                 const std::string cpu_name =
10226                   this->tag_cpu_name_value(out_attr[i].int_value());
10227                 // FIXME:  If we see an unknown CPU, this will be set
10228                 // to "<unknown CPU n>", where n is the attribute value.
10229                 // This is different from BFD, which leaves the name alone.
10230                 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10231               }
10232           }
10233           break;
10234
10235         case elfcpp::Tag_ARM_ISA_use:
10236         case elfcpp::Tag_THUMB_ISA_use:
10237         case elfcpp::Tag_WMMX_arch:
10238         case elfcpp::Tag_Advanced_SIMD_arch:
10239           // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10240         case elfcpp::Tag_ABI_FP_rounding:
10241         case elfcpp::Tag_ABI_FP_exceptions:
10242         case elfcpp::Tag_ABI_FP_user_exceptions:
10243         case elfcpp::Tag_ABI_FP_number_model:
10244         case elfcpp::Tag_VFP_HP_extension:
10245         case elfcpp::Tag_CPU_unaligned_access:
10246         case elfcpp::Tag_T2EE_use:
10247         case elfcpp::Tag_Virtualization_use:
10248         case elfcpp::Tag_MPextension_use:
10249           // Use the largest value specified.
10250           if (in_attr[i].int_value() > out_attr[i].int_value())
10251             out_attr[i].set_int_value(in_attr[i].int_value());
10252           break;
10253
10254         case elfcpp::Tag_ABI_align8_preserved:
10255         case elfcpp::Tag_ABI_PCS_RO_data:
10256           // Use the smallest value specified.
10257           if (in_attr[i].int_value() < out_attr[i].int_value())
10258             out_attr[i].set_int_value(in_attr[i].int_value());
10259           break;
10260
10261         case elfcpp::Tag_ABI_align8_needed:
10262           if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10263               && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10264                   || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10265                       == 0)))
10266             {
10267               // This error message should be enabled once all non-conformant
10268               // binaries in the toolchain have had the attributes set
10269               // properly.
10270               // gold_error(_("output 8-byte data alignment conflicts with %s"),
10271               //            name);
10272             }
10273           // Fall through.
10274         case elfcpp::Tag_ABI_FP_denormal:
10275         case elfcpp::Tag_ABI_PCS_GOT_use:
10276           {
10277             // These tags have 0 = don't care, 1 = strong requirement,
10278             // 2 = weak requirement.
10279             static const int order_021[3] = {0, 2, 1};
10280
10281             // Use the "greatest" from the sequence 0, 2, 1, or the largest
10282             // value if greater than 2 (for future-proofing).
10283             if ((in_attr[i].int_value() > 2
10284                  && in_attr[i].int_value() > out_attr[i].int_value())
10285                 || (in_attr[i].int_value() <= 2
10286                     && out_attr[i].int_value() <= 2
10287                     && (order_021[in_attr[i].int_value()]
10288                         > order_021[out_attr[i].int_value()])))
10289               out_attr[i].set_int_value(in_attr[i].int_value());
10290           }
10291           break;
10292
10293         case elfcpp::Tag_CPU_arch_profile:
10294           if (out_attr[i].int_value() != in_attr[i].int_value())
10295             {
10296               // 0 will merge with anything.
10297               // 'A' and 'S' merge to 'A'.
10298               // 'R' and 'S' merge to 'R'.
10299               // 'M' and 'A|R|S' is an error.
10300               if (out_attr[i].int_value() == 0
10301                   || (out_attr[i].int_value() == 'S'
10302                       && (in_attr[i].int_value() == 'A'
10303                           || in_attr[i].int_value() == 'R')))
10304                 out_attr[i].set_int_value(in_attr[i].int_value());
10305               else if (in_attr[i].int_value() == 0
10306                        || (in_attr[i].int_value() == 'S'
10307                            && (out_attr[i].int_value() == 'A'
10308                                || out_attr[i].int_value() == 'R')))
10309                 ; // Do nothing.
10310               else if (parameters->options().warn_mismatch())
10311                 {
10312                   gold_error
10313                     (_("conflicting architecture profiles %c/%c"),
10314                      in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10315                      out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10316                 }
10317             }
10318           break;
10319         case elfcpp::Tag_VFP_arch:
10320             {
10321               static const struct
10322               {
10323                   int ver;
10324                   int regs;
10325               } vfp_versions[7] =
10326                 {
10327                   {0, 0},
10328                   {1, 16},
10329                   {2, 16},
10330                   {3, 32},
10331                   {3, 16},
10332                   {4, 32},
10333                   {4, 16}
10334                 };
10335
10336               // Values greater than 6 aren't defined, so just pick the
10337               // biggest.
10338               if (in_attr[i].int_value() > 6
10339                   && in_attr[i].int_value() > out_attr[i].int_value())
10340                 {
10341                   *out_attr = *in_attr;
10342                   break;
10343                 }
10344               // The output uses the superset of input features
10345               // (ISA version) and registers.
10346               int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10347                                  vfp_versions[out_attr[i].int_value()].ver);
10348               int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10349                                   vfp_versions[out_attr[i].int_value()].regs);
10350               // This assumes all possible supersets are also a valid
10351               // options.
10352               int newval;
10353               for (newval = 6; newval > 0; newval--)
10354                 {
10355                   if (regs == vfp_versions[newval].regs
10356                       && ver == vfp_versions[newval].ver)
10357                     break;
10358                 }
10359               out_attr[i].set_int_value(newval);
10360             }
10361           break;
10362         case elfcpp::Tag_PCS_config:
10363           if (out_attr[i].int_value() == 0)
10364             out_attr[i].set_int_value(in_attr[i].int_value());
10365           else if (in_attr[i].int_value() != 0
10366                    && out_attr[i].int_value() != 0
10367                    && parameters->options().warn_mismatch())
10368             {
10369               // It's sometimes ok to mix different configs, so this is only
10370               // a warning.
10371               gold_warning(_("%s: conflicting platform configuration"), name);
10372             }
10373           break;
10374         case elfcpp::Tag_ABI_PCS_R9_use:
10375           if (in_attr[i].int_value() != out_attr[i].int_value()
10376               && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10377               && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10378               && parameters->options().warn_mismatch())
10379             {
10380               gold_error(_("%s: conflicting use of R9"), name);
10381             }
10382           if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10383             out_attr[i].set_int_value(in_attr[i].int_value());
10384           break;
10385         case elfcpp::Tag_ABI_PCS_RW_data:
10386           if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10387               && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10388                   != elfcpp::AEABI_R9_SB)
10389               && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10390                   != elfcpp::AEABI_R9_unused)
10391               && parameters->options().warn_mismatch())
10392             {
10393               gold_error(_("%s: SB relative addressing conflicts with use "
10394                            "of R9"),
10395                            name);
10396             }
10397           // Use the smallest value specified.
10398           if (in_attr[i].int_value() < out_attr[i].int_value())
10399             out_attr[i].set_int_value(in_attr[i].int_value());
10400           break;
10401         case elfcpp::Tag_ABI_PCS_wchar_t:
10402           if (out_attr[i].int_value()
10403               && in_attr[i].int_value()
10404               && out_attr[i].int_value() != in_attr[i].int_value()
10405               && parameters->options().warn_mismatch()
10406               && parameters->options().wchar_size_warning())
10407             {
10408               gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10409                              "use %u-byte wchar_t; use of wchar_t values "
10410                              "across objects may fail"),
10411                            name, in_attr[i].int_value(),
10412                            out_attr[i].int_value());
10413             }
10414           else if (in_attr[i].int_value() && !out_attr[i].int_value())
10415             out_attr[i].set_int_value(in_attr[i].int_value());
10416           break;
10417         case elfcpp::Tag_ABI_enum_size:
10418           if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10419             {
10420               if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10421                   || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10422                 {
10423                   // The existing object is compatible with anything.
10424                   // Use whatever requirements the new object has.
10425                   out_attr[i].set_int_value(in_attr[i].int_value());
10426                 }
10427               else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10428                        && out_attr[i].int_value() != in_attr[i].int_value()
10429                        && parameters->options().warn_mismatch()
10430                        && parameters->options().enum_size_warning())
10431                 {
10432                   unsigned int in_value = in_attr[i].int_value();
10433                   unsigned int out_value = out_attr[i].int_value();
10434                   gold_warning(_("%s uses %s enums yet the output is to use "
10435                                  "%s enums; use of enum values across objects "
10436                                  "may fail"),
10437                                name,
10438                                this->aeabi_enum_name(in_value).c_str(),
10439                                this->aeabi_enum_name(out_value).c_str());
10440                 }
10441             }
10442           break;
10443         case elfcpp::Tag_ABI_VFP_args:
10444           // Aready done.
10445           break;
10446         case elfcpp::Tag_ABI_WMMX_args:
10447           if (in_attr[i].int_value() != out_attr[i].int_value()
10448               && parameters->options().warn_mismatch())
10449             {
10450               gold_error(_("%s uses iWMMXt register arguments, output does "
10451                            "not"),
10452                          name);
10453             }
10454           break;
10455         case Object_attribute::Tag_compatibility:
10456           // Merged in target-independent code.
10457           break;
10458         case elfcpp::Tag_ABI_HardFP_use:
10459           // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10460           if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10461               || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10462             out_attr[i].set_int_value(3);
10463           else if (in_attr[i].int_value() > out_attr[i].int_value())
10464             out_attr[i].set_int_value(in_attr[i].int_value());
10465           break;
10466         case elfcpp::Tag_ABI_FP_16bit_format:
10467           if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10468             {
10469               if (in_attr[i].int_value() != out_attr[i].int_value()
10470                   && parameters->options().warn_mismatch())
10471                 gold_error(_("fp16 format mismatch between %s and output"),
10472                            name);
10473             }
10474           if (in_attr[i].int_value() != 0)
10475             out_attr[i].set_int_value(in_attr[i].int_value());
10476           break;
10477
10478         case elfcpp::Tag_DIV_use:
10479           // This tag is set to zero if we can use UDIV and SDIV in Thumb
10480           // mode on a v7-M or v7-R CPU; to one if we can not use UDIV or
10481           // SDIV at all; and to two if we can use UDIV or SDIV on a v7-A
10482           // CPU.  We will merge as follows: If the input attribute's value
10483           // is one then the output attribute's value remains unchanged.  If
10484           // the input attribute's value is zero or two then if the output
10485           // attribute's value is one the output value is set to the input
10486           // value, otherwise the output value must be the same as the
10487           // inputs.  */ 
10488           if (in_attr[i].int_value() != 1 && out_attr[i].int_value() != 1) 
10489             { 
10490               if (in_attr[i].int_value() != out_attr[i].int_value())
10491                 {
10492                   gold_error(_("DIV usage mismatch between %s and output"),
10493                              name);
10494                 }
10495             } 
10496
10497           if (in_attr[i].int_value() != 1)
10498             out_attr[i].set_int_value(in_attr[i].int_value()); 
10499           
10500           break;
10501
10502         case elfcpp::Tag_MPextension_use_legacy:
10503           // We don't output objects with Tag_MPextension_use_legacy - we
10504           // move the value to Tag_MPextension_use.
10505           if (in_attr[i].int_value() != 0
10506               && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10507             {
10508               if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10509                   != in_attr[i].int_value())
10510                 {
10511                   gold_error(_("%s has has both the current and legacy "
10512                                "Tag_MPextension_use attributes"), 
10513                              name);
10514                 }
10515             }
10516
10517           if (in_attr[i].int_value()
10518               > out_attr[elfcpp::Tag_MPextension_use].int_value())
10519             out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10520
10521           break;
10522
10523         case elfcpp::Tag_nodefaults:
10524           // This tag is set if it exists, but the value is unused (and is
10525           // typically zero).  We don't actually need to do anything here -
10526           // the merge happens automatically when the type flags are merged
10527           // below.
10528           break;
10529         case elfcpp::Tag_also_compatible_with:
10530           // Already done in Tag_CPU_arch.
10531           break;
10532         case elfcpp::Tag_conformance:
10533           // Keep the attribute if it matches.  Throw it away otherwise.
10534           // No attribute means no claim to conform.
10535           if (in_attr[i].string_value() != out_attr[i].string_value())
10536             out_attr[i].set_string_value("");
10537           break;
10538
10539         default:
10540           {
10541             const char* err_object = NULL;
10542
10543             // The "known_obj_attributes" table does contain some undefined
10544             // attributes.  Ensure that there are unused.
10545             if (out_attr[i].int_value() != 0
10546                 || out_attr[i].string_value() != "")
10547               err_object = "output";
10548             else if (in_attr[i].int_value() != 0
10549                      || in_attr[i].string_value() != "")
10550               err_object = name;
10551
10552             if (err_object != NULL
10553                 && parameters->options().warn_mismatch())
10554               {
10555                 // Attribute numbers >=64 (mod 128) can be safely ignored.
10556                 if ((i & 127) < 64)
10557                   gold_error(_("%s: unknown mandatory EABI object attribute "
10558                                "%d"),
10559                              err_object, i);
10560                 else
10561                   gold_warning(_("%s: unknown EABI object attribute %d"),
10562                                err_object, i);
10563               }
10564
10565             // Only pass on attributes that match in both inputs.
10566             if (!in_attr[i].matches(out_attr[i]))
10567               {
10568                 out_attr[i].set_int_value(0);
10569                 out_attr[i].set_string_value("");
10570               }
10571           }
10572         }
10573
10574       // If out_attr was copied from in_attr then it won't have a type yet.
10575       if (in_attr[i].type() && !out_attr[i].type())
10576         out_attr[i].set_type(in_attr[i].type());
10577     }
10578
10579   // Merge Tag_compatibility attributes and any common GNU ones.
10580   this->attributes_section_data_->merge(name, pasd);
10581
10582   // Check for any attributes not known on ARM.
10583   typedef Vendor_object_attributes::Other_attributes Other_attributes;
10584   const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10585   Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10586   Other_attributes* out_other_attributes =
10587     this->attributes_section_data_->other_attributes(vendor);
10588   Other_attributes::iterator out_iter = out_other_attributes->begin();
10589
10590   while (in_iter != in_other_attributes->end()
10591          || out_iter != out_other_attributes->end())
10592     {
10593       const char* err_object = NULL;
10594       int err_tag = 0;
10595
10596       // The tags for each list are in numerical order.
10597       // If the tags are equal, then merge.
10598       if (out_iter != out_other_attributes->end()
10599           && (in_iter == in_other_attributes->end()
10600               || in_iter->first > out_iter->first))
10601         {
10602           // This attribute only exists in output.  We can't merge, and we
10603           // don't know what the tag means, so delete it.
10604           err_object = "output";
10605           err_tag = out_iter->first;
10606           int saved_tag = out_iter->first;
10607           delete out_iter->second;
10608           out_other_attributes->erase(out_iter); 
10609           out_iter = out_other_attributes->upper_bound(saved_tag);
10610         }
10611       else if (in_iter != in_other_attributes->end()
10612                && (out_iter != out_other_attributes->end()
10613                    || in_iter->first < out_iter->first))
10614         {
10615           // This attribute only exists in input. We can't merge, and we
10616           // don't know what the tag means, so ignore it.
10617           err_object = name;
10618           err_tag = in_iter->first;
10619           ++in_iter;
10620         }
10621       else // The tags are equal.
10622         {
10623           // As present, all attributes in the list are unknown, and
10624           // therefore can't be merged meaningfully.
10625           err_object = "output";
10626           err_tag = out_iter->first;
10627
10628           //  Only pass on attributes that match in both inputs.
10629           if (!in_iter->second->matches(*(out_iter->second)))
10630             {
10631               // No match.  Delete the attribute.
10632               int saved_tag = out_iter->first;
10633               delete out_iter->second;
10634               out_other_attributes->erase(out_iter);
10635               out_iter = out_other_attributes->upper_bound(saved_tag);
10636             }
10637           else
10638             {
10639               // Matched.  Keep the attribute and move to the next.
10640               ++out_iter;
10641               ++in_iter;
10642             }
10643         }
10644
10645       if (err_object && parameters->options().warn_mismatch())
10646         {
10647           // Attribute numbers >=64 (mod 128) can be safely ignored.  */
10648           if ((err_tag & 127) < 64)
10649             {
10650               gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10651                          err_object, err_tag);
10652             }
10653           else
10654             {
10655               gold_warning(_("%s: unknown EABI object attribute %d"),
10656                            err_object, err_tag);
10657             }
10658         }
10659     }
10660 }
10661
10662 // Stub-generation methods for Target_arm.
10663
10664 // Make a new Arm_input_section object.
10665
10666 template<bool big_endian>
10667 Arm_input_section<big_endian>*
10668 Target_arm<big_endian>::new_arm_input_section(
10669     Relobj* relobj,
10670     unsigned int shndx)
10671 {
10672   Section_id sid(relobj, shndx);
10673
10674   Arm_input_section<big_endian>* arm_input_section =
10675     new Arm_input_section<big_endian>(relobj, shndx);
10676   arm_input_section->init();
10677
10678   // Register new Arm_input_section in map for look-up.
10679   std::pair<typename Arm_input_section_map::iterator, bool> ins =
10680     this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
10681
10682   // Make sure that it we have not created another Arm_input_section
10683   // for this input section already.
10684   gold_assert(ins.second);
10685
10686   return arm_input_section; 
10687 }
10688
10689 // Find the Arm_input_section object corresponding to the SHNDX-th input
10690 // section of RELOBJ.
10691
10692 template<bool big_endian>
10693 Arm_input_section<big_endian>*
10694 Target_arm<big_endian>::find_arm_input_section(
10695     Relobj* relobj,
10696     unsigned int shndx) const
10697 {
10698   Section_id sid(relobj, shndx);
10699   typename Arm_input_section_map::const_iterator p =
10700     this->arm_input_section_map_.find(sid);
10701   return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
10702 }
10703
10704 // Make a new stub table.
10705
10706 template<bool big_endian>
10707 Stub_table<big_endian>*
10708 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
10709 {
10710   Stub_table<big_endian>* stub_table =
10711     new Stub_table<big_endian>(owner);
10712   this->stub_tables_.push_back(stub_table);
10713
10714   stub_table->set_address(owner->address() + owner->data_size());
10715   stub_table->set_file_offset(owner->offset() + owner->data_size());
10716   stub_table->finalize_data_size();
10717
10718   return stub_table;
10719 }
10720
10721 // Scan a relocation for stub generation.
10722
10723 template<bool big_endian>
10724 void
10725 Target_arm<big_endian>::scan_reloc_for_stub(
10726     const Relocate_info<32, big_endian>* relinfo,
10727     unsigned int r_type,
10728     const Sized_symbol<32>* gsym,
10729     unsigned int r_sym,
10730     const Symbol_value<32>* psymval,
10731     elfcpp::Elf_types<32>::Elf_Swxword addend,
10732     Arm_address address)
10733 {
10734   typedef typename Target_arm<big_endian>::Relocate Relocate;
10735
10736   const Arm_relobj<big_endian>* arm_relobj =
10737     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10738
10739   bool target_is_thumb;
10740   Symbol_value<32> symval;
10741   if (gsym != NULL)
10742     {
10743       // This is a global symbol.  Determine if we use PLT and if the
10744       // final target is THUMB.
10745       if (gsym->use_plt_offset(Relocate::reloc_is_non_pic(r_type)))
10746         {
10747           // This uses a PLT, change the symbol value.
10748           symval.set_output_value(this->plt_section()->address()
10749                                   + gsym->plt_offset());
10750           psymval = &symval;
10751           target_is_thumb = false;
10752         }
10753       else if (gsym->is_undefined())
10754         // There is no need to generate a stub symbol is undefined.
10755         return;
10756       else
10757         {
10758           target_is_thumb =
10759             ((gsym->type() == elfcpp::STT_ARM_TFUNC)
10760              || (gsym->type() == elfcpp::STT_FUNC
10761                  && !gsym->is_undefined()
10762                  && ((psymval->value(arm_relobj, 0) & 1) != 0)));
10763         }
10764     }
10765   else
10766     {
10767       // This is a local symbol.  Determine if the final target is THUMB.
10768       target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
10769     }
10770
10771   // Strip LSB if this points to a THUMB target.
10772   const Arm_reloc_property* reloc_property =
10773     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10774   gold_assert(reloc_property != NULL);
10775   if (target_is_thumb
10776       && reloc_property->uses_thumb_bit()
10777       && ((psymval->value(arm_relobj, 0) & 1) != 0))
10778     {
10779       Arm_address stripped_value =
10780         psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
10781       symval.set_output_value(stripped_value);
10782       psymval = &symval;
10783     } 
10784
10785   // Get the symbol value.
10786   Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
10787
10788   // Owing to pipelining, the PC relative branches below actually skip
10789   // two instructions when the branch offset is 0.
10790   Arm_address destination;
10791   switch (r_type)
10792     {
10793     case elfcpp::R_ARM_CALL:
10794     case elfcpp::R_ARM_JUMP24:
10795     case elfcpp::R_ARM_PLT32:
10796       // ARM branches.
10797       destination = value + addend + 8;
10798       break;
10799     case elfcpp::R_ARM_THM_CALL:
10800     case elfcpp::R_ARM_THM_XPC22:
10801     case elfcpp::R_ARM_THM_JUMP24:
10802     case elfcpp::R_ARM_THM_JUMP19:
10803       // THUMB branches.
10804       destination = value + addend + 4;
10805       break;
10806     default:
10807       gold_unreachable();
10808     }
10809
10810   Reloc_stub* stub = NULL;
10811   Stub_type stub_type =
10812     Reloc_stub::stub_type_for_reloc(r_type, address, destination,
10813                                     target_is_thumb);
10814   if (stub_type != arm_stub_none)
10815     {
10816       // Try looking up an existing stub from a stub table.
10817       Stub_table<big_endian>* stub_table = 
10818         arm_relobj->stub_table(relinfo->data_shndx);
10819       gold_assert(stub_table != NULL);
10820    
10821       // Locate stub by destination.
10822       Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
10823
10824       // Create a stub if there is not one already
10825       stub = stub_table->find_reloc_stub(stub_key);
10826       if (stub == NULL)
10827         {
10828           // create a new stub and add it to stub table.
10829           stub = this->stub_factory().make_reloc_stub(stub_type);
10830           stub_table->add_reloc_stub(stub, stub_key);
10831         }
10832
10833       // Record the destination address.
10834       stub->set_destination_address(destination
10835                                     | (target_is_thumb ? 1 : 0));
10836     }
10837
10838   // For Cortex-A8, we need to record a relocation at 4K page boundary.
10839   if (this->fix_cortex_a8_
10840       && (r_type == elfcpp::R_ARM_THM_JUMP24
10841           || r_type == elfcpp::R_ARM_THM_JUMP19
10842           || r_type == elfcpp::R_ARM_THM_CALL
10843           || r_type == elfcpp::R_ARM_THM_XPC22)
10844       && (address & 0xfffU) == 0xffeU)
10845     {
10846       // Found a candidate.  Note we haven't checked the destination is
10847       // within 4K here: if we do so (and don't create a record) we can't
10848       // tell that a branch should have been relocated when scanning later.
10849       this->cortex_a8_relocs_info_[address] =
10850         new Cortex_a8_reloc(stub, r_type,
10851                             destination | (target_is_thumb ? 1 : 0));
10852     }
10853 }
10854
10855 // This function scans a relocation sections for stub generation.
10856 // The template parameter Relocate must be a class type which provides
10857 // a single function, relocate(), which implements the machine
10858 // specific part of a relocation.
10859
10860 // BIG_ENDIAN is the endianness of the data.  SH_TYPE is the section type:
10861 // SHT_REL or SHT_RELA.
10862
10863 // PRELOCS points to the relocation data.  RELOC_COUNT is the number
10864 // of relocs.  OUTPUT_SECTION is the output section.
10865 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
10866 // mapped to output offsets.
10867
10868 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
10869 // VIEW_SIZE is the size.  These refer to the input section, unless
10870 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
10871 // the output section.
10872
10873 template<bool big_endian>
10874 template<int sh_type>
10875 void inline
10876 Target_arm<big_endian>::scan_reloc_section_for_stubs(
10877     const Relocate_info<32, big_endian>* relinfo,
10878     const unsigned char* prelocs,
10879     size_t reloc_count,
10880     Output_section* output_section,
10881     bool needs_special_offset_handling,
10882     const unsigned char* view,
10883     elfcpp::Elf_types<32>::Elf_Addr view_address,
10884     section_size_type)
10885 {
10886   typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
10887   const int reloc_size =
10888     Reloc_types<sh_type, 32, big_endian>::reloc_size;
10889
10890   Arm_relobj<big_endian>* arm_object =
10891     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10892   unsigned int local_count = arm_object->local_symbol_count();
10893
10894   Comdat_behavior comdat_behavior = CB_UNDETERMINED;
10895
10896   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
10897     {
10898       Reltype reloc(prelocs);
10899
10900       typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
10901       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
10902       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
10903
10904       r_type = this->get_real_reloc_type(r_type);
10905
10906       // Only a few relocation types need stubs.
10907       if ((r_type != elfcpp::R_ARM_CALL)
10908          && (r_type != elfcpp::R_ARM_JUMP24)
10909          && (r_type != elfcpp::R_ARM_PLT32)
10910          && (r_type != elfcpp::R_ARM_THM_CALL)
10911          && (r_type != elfcpp::R_ARM_THM_XPC22)
10912          && (r_type != elfcpp::R_ARM_THM_JUMP24)
10913          && (r_type != elfcpp::R_ARM_THM_JUMP19)
10914          && (r_type != elfcpp::R_ARM_V4BX))
10915         continue;
10916
10917       section_offset_type offset =
10918         convert_to_section_size_type(reloc.get_r_offset());
10919
10920       if (needs_special_offset_handling)
10921         {
10922           offset = output_section->output_offset(relinfo->object,
10923                                                  relinfo->data_shndx,
10924                                                  offset);
10925           if (offset == -1)
10926             continue;
10927         }
10928
10929       // Create a v4bx stub if --fix-v4bx-interworking is used.
10930       if (r_type == elfcpp::R_ARM_V4BX)
10931         {
10932           if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
10933             {
10934               // Get the BX instruction.
10935               typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
10936               const Valtype* wv =
10937                 reinterpret_cast<const Valtype*>(view + offset);
10938               elfcpp::Elf_types<32>::Elf_Swxword insn =
10939                 elfcpp::Swap<32, big_endian>::readval(wv);
10940               const uint32_t reg = (insn & 0xf);
10941
10942               if (reg < 0xf)
10943                 {
10944                   // Try looking up an existing stub from a stub table.
10945                   Stub_table<big_endian>* stub_table =
10946                     arm_object->stub_table(relinfo->data_shndx);
10947                   gold_assert(stub_table != NULL);
10948
10949                   if (stub_table->find_arm_v4bx_stub(reg) == NULL)
10950                     {
10951                       // create a new stub and add it to stub table.
10952                       Arm_v4bx_stub* stub =
10953                         this->stub_factory().make_arm_v4bx_stub(reg);
10954                       gold_assert(stub != NULL);
10955                       stub_table->add_arm_v4bx_stub(stub);
10956                     }
10957                 }
10958             }
10959           continue;
10960         }
10961
10962       // Get the addend.
10963       Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
10964       elfcpp::Elf_types<32>::Elf_Swxword addend =
10965         stub_addend_reader(r_type, view + offset, reloc);
10966
10967       const Sized_symbol<32>* sym;
10968
10969       Symbol_value<32> symval;
10970       const Symbol_value<32> *psymval;
10971       bool is_defined_in_discarded_section;
10972       unsigned int shndx;
10973       if (r_sym < local_count)
10974         {
10975           sym = NULL;
10976           psymval = arm_object->local_symbol(r_sym);
10977
10978           // If the local symbol belongs to a section we are discarding,
10979           // and that section is a debug section, try to find the
10980           // corresponding kept section and map this symbol to its
10981           // counterpart in the kept section.  The symbol must not 
10982           // correspond to a section we are folding.
10983           bool is_ordinary;
10984           shndx = psymval->input_shndx(&is_ordinary);
10985           is_defined_in_discarded_section =
10986             (is_ordinary
10987              && shndx != elfcpp::SHN_UNDEF
10988              && !arm_object->is_section_included(shndx)
10989              && !relinfo->symtab->is_section_folded(arm_object, shndx));
10990
10991           // We need to compute the would-be final value of this local
10992           // symbol.
10993           if (!is_defined_in_discarded_section)
10994             {
10995               typedef Sized_relobj<32, big_endian> ObjType;
10996               typename ObjType::Compute_final_local_value_status status =
10997                 arm_object->compute_final_local_value(r_sym, psymval, &symval,
10998                                                       relinfo->symtab); 
10999               if (status == ObjType::CFLV_OK)
11000                 {
11001                   // Currently we cannot handle a branch to a target in
11002                   // a merged section.  If this is the case, issue an error
11003                   // and also free the merge symbol value.
11004                   if (!symval.has_output_value())
11005                     {
11006                       const std::string& section_name =
11007                         arm_object->section_name(shndx);
11008                       arm_object->error(_("cannot handle branch to local %u "
11009                                           "in a merged section %s"),
11010                                         r_sym, section_name.c_str());
11011                     }
11012                   psymval = &symval;
11013                 }
11014               else
11015                 {
11016                   // We cannot determine the final value.
11017                   continue;  
11018                 }
11019             }
11020         }
11021       else
11022         {
11023           const Symbol* gsym;
11024           gsym = arm_object->global_symbol(r_sym);
11025           gold_assert(gsym != NULL);
11026           if (gsym->is_forwarder())
11027             gsym = relinfo->symtab->resolve_forwards(gsym);
11028
11029           sym = static_cast<const Sized_symbol<32>*>(gsym);
11030           if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11031             symval.set_output_symtab_index(sym->symtab_index());
11032           else
11033             symval.set_no_output_symtab_entry();
11034
11035           // We need to compute the would-be final value of this global
11036           // symbol.
11037           const Symbol_table* symtab = relinfo->symtab;
11038           const Sized_symbol<32>* sized_symbol =
11039             symtab->get_sized_symbol<32>(gsym);
11040           Symbol_table::Compute_final_value_status status;
11041           Arm_address value =
11042             symtab->compute_final_value<32>(sized_symbol, &status);
11043
11044           // Skip this if the symbol has not output section.
11045           if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11046             continue;
11047           symval.set_output_value(value);
11048
11049           if (gsym->type() == elfcpp::STT_TLS)
11050             symval.set_is_tls_symbol();
11051           else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11052             symval.set_is_ifunc_symbol();
11053           psymval = &symval;
11054
11055           is_defined_in_discarded_section =
11056             (gsym->is_defined_in_discarded_section()
11057              && gsym->is_undefined());
11058           shndx = 0;
11059         }
11060
11061       Symbol_value<32> symval2;
11062       if (is_defined_in_discarded_section)
11063         {
11064           if (comdat_behavior == CB_UNDETERMINED)
11065             {
11066               std::string name = arm_object->section_name(relinfo->data_shndx);
11067               comdat_behavior = get_comdat_behavior(name.c_str());
11068             }
11069           if (comdat_behavior == CB_PRETEND)
11070             {
11071               // FIXME: This case does not work for global symbols.
11072               // We have no place to store the original section index.
11073               // Fortunately this does not matter for comdat sections,
11074               // only for sections explicitly discarded by a linker
11075               // script.
11076               bool found;
11077               typename elfcpp::Elf_types<32>::Elf_Addr value =
11078                 arm_object->map_to_kept_section(shndx, &found);
11079               if (found)
11080                 symval2.set_output_value(value + psymval->input_value());
11081               else
11082                 symval2.set_output_value(0);
11083             }
11084           else
11085             {
11086               if (comdat_behavior == CB_WARNING)
11087                 gold_warning_at_location(relinfo, i, offset,
11088                                          _("relocation refers to discarded "
11089                                            "section"));
11090               symval2.set_output_value(0);
11091             }
11092           symval2.set_no_output_symtab_entry();
11093           psymval = &symval2;
11094         }
11095
11096       // If symbol is a section symbol, we don't know the actual type of
11097       // destination.  Give up.
11098       if (psymval->is_section_symbol())
11099         continue;
11100
11101       this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11102                                 addend, view_address + offset);
11103     }
11104 }
11105
11106 // Scan an input section for stub generation.
11107
11108 template<bool big_endian>
11109 void
11110 Target_arm<big_endian>::scan_section_for_stubs(
11111     const Relocate_info<32, big_endian>* relinfo,
11112     unsigned int sh_type,
11113     const unsigned char* prelocs,
11114     size_t reloc_count,
11115     Output_section* output_section,
11116     bool needs_special_offset_handling,
11117     const unsigned char* view,
11118     Arm_address view_address,
11119     section_size_type view_size)
11120 {
11121   if (sh_type == elfcpp::SHT_REL)
11122     this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11123         relinfo,
11124         prelocs,
11125         reloc_count,
11126         output_section,
11127         needs_special_offset_handling,
11128         view,
11129         view_address,
11130         view_size);
11131   else if (sh_type == elfcpp::SHT_RELA)
11132     // We do not support RELA type relocations yet.  This is provided for
11133     // completeness.
11134     this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11135         relinfo,
11136         prelocs,
11137         reloc_count,
11138         output_section,
11139         needs_special_offset_handling,
11140         view,
11141         view_address,
11142         view_size);
11143   else
11144     gold_unreachable();
11145 }
11146
11147 // Group input sections for stub generation.
11148 //
11149 // We goup input sections in an output sections so that the total size,
11150 // including any padding space due to alignment is smaller than GROUP_SIZE
11151 // unless the only input section in group is bigger than GROUP_SIZE already.
11152 // Then an ARM stub table is created to follow the last input section
11153 // in group.  For each group an ARM stub table is created an is placed
11154 // after the last group.  If STUB_ALWATS_AFTER_BRANCH is false, we further
11155 // extend the group after the stub table.
11156
11157 template<bool big_endian>
11158 void
11159 Target_arm<big_endian>::group_sections(
11160     Layout* layout,
11161     section_size_type group_size,
11162     bool stubs_always_after_branch)
11163 {
11164   // Group input sections and insert stub table
11165   Layout::Section_list section_list;
11166   layout->get_allocated_sections(&section_list);
11167   for (Layout::Section_list::const_iterator p = section_list.begin();
11168        p != section_list.end();
11169        ++p)
11170     {
11171       Arm_output_section<big_endian>* output_section =
11172         Arm_output_section<big_endian>::as_arm_output_section(*p);
11173       output_section->group_sections(group_size, stubs_always_after_branch,
11174                                      this);
11175     }
11176 }
11177
11178 // Relaxation hook.  This is where we do stub generation.
11179
11180 template<bool big_endian>
11181 bool
11182 Target_arm<big_endian>::do_relax(
11183     int pass,
11184     const Input_objects* input_objects,
11185     Symbol_table* symtab,
11186     Layout* layout)
11187 {
11188   // No need to generate stubs if this is a relocatable link.
11189   gold_assert(!parameters->options().relocatable());
11190
11191   // If this is the first pass, we need to group input sections into
11192   // stub groups.
11193   bool done_exidx_fixup = false;
11194   typedef typename Stub_table_list::iterator Stub_table_iterator;
11195   if (pass == 1)
11196     {
11197       // Determine the stub group size.  The group size is the absolute
11198       // value of the parameter --stub-group-size.  If --stub-group-size
11199       // is passed a negative value, we restict stubs to be always after
11200       // the stubbed branches.
11201       int32_t stub_group_size_param =
11202         parameters->options().stub_group_size();
11203       bool stubs_always_after_branch = stub_group_size_param < 0;
11204       section_size_type stub_group_size = abs(stub_group_size_param);
11205
11206       if (stub_group_size == 1)
11207         {
11208           // Default value.
11209           // Thumb branch range is +-4MB has to be used as the default
11210           // maximum size (a given section can contain both ARM and Thumb
11211           // code, so the worst case has to be taken into account).  If we are
11212           // fixing cortex-a8 errata, the branch range has to be even smaller,
11213           // since wide conditional branch has a range of +-1MB only.
11214           //
11215           // This value is 48K less than that, which allows for 4096
11216           // 12-byte stubs.  If we exceed that, then we will fail to link.
11217           // The user will have to relink with an explicit group size
11218           // option.
11219             stub_group_size = 4145152;
11220         }
11221
11222       // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11223       // page as the first half of a 32-bit branch straddling two 4K pages.
11224       // This is a crude way of enforcing that.  In addition, long conditional
11225       // branches of THUMB-2 have a range of +-1M.  If we are fixing cortex-A8
11226       // erratum, limit the group size to  (1M - 12k) to avoid unreachable
11227       // cortex-A8 stubs from long conditional branches.
11228       if (this->fix_cortex_a8_)
11229         {
11230           stubs_always_after_branch = true;
11231           const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11232           stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11233         }
11234
11235       group_sections(layout, stub_group_size, stubs_always_after_branch);
11236      
11237       // Also fix .ARM.exidx section coverage.
11238       Arm_output_section<big_endian>* exidx_output_section = NULL;
11239       for (Layout::Section_list::const_iterator p =
11240              layout->section_list().begin();
11241            p != layout->section_list().end();
11242            ++p)
11243         if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11244           {
11245             if (exidx_output_section == NULL)
11246               exidx_output_section =
11247                 Arm_output_section<big_endian>::as_arm_output_section(*p);
11248             else
11249               // We cannot handle this now.
11250               gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11251                            "non-relocatable link"),
11252                           exidx_output_section->name(),
11253                           (*p)->name());
11254           }
11255
11256       if (exidx_output_section != NULL)
11257         {
11258           this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11259                                    symtab);
11260           done_exidx_fixup = true;
11261         }
11262     }
11263   else
11264     {
11265       // If this is not the first pass, addresses and file offsets have
11266       // been reset at this point, set them here.
11267       for (Stub_table_iterator sp = this->stub_tables_.begin();
11268            sp != this->stub_tables_.end();
11269            ++sp)
11270         {
11271           Arm_input_section<big_endian>* owner = (*sp)->owner();
11272           off_t off = align_address(owner->original_size(),
11273                                     (*sp)->addralign());
11274           (*sp)->set_address_and_file_offset(owner->address() + off,
11275                                              owner->offset() + off);
11276         }
11277     }
11278
11279   // The Cortex-A8 stubs are sensitive to layout of code sections.  At the
11280   // beginning of each relaxation pass, just blow away all the stubs.
11281   // Alternatively, we could selectively remove only the stubs and reloc
11282   // information for code sections that have moved since the last pass.
11283   // That would require more book-keeping.
11284   if (this->fix_cortex_a8_)
11285     {
11286       // Clear all Cortex-A8 reloc information.
11287       for (typename Cortex_a8_relocs_info::const_iterator p =
11288              this->cortex_a8_relocs_info_.begin();
11289            p != this->cortex_a8_relocs_info_.end();
11290            ++p)
11291         delete p->second;
11292       this->cortex_a8_relocs_info_.clear();
11293
11294       // Remove all Cortex-A8 stubs.
11295       for (Stub_table_iterator sp = this->stub_tables_.begin();
11296            sp != this->stub_tables_.end();
11297            ++sp)
11298         (*sp)->remove_all_cortex_a8_stubs();
11299     }
11300   
11301   // Scan relocs for relocation stubs
11302   for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11303        op != input_objects->relobj_end();
11304        ++op)
11305     {
11306       Arm_relobj<big_endian>* arm_relobj =
11307         Arm_relobj<big_endian>::as_arm_relobj(*op);
11308       arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11309     }
11310
11311   // Check all stub tables to see if any of them have their data sizes
11312   // or addresses alignments changed.  These are the only things that
11313   // matter.
11314   bool any_stub_table_changed = false;
11315   Unordered_set<const Output_section*> sections_needing_adjustment;
11316   for (Stub_table_iterator sp = this->stub_tables_.begin();
11317        (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11318        ++sp)
11319     {
11320       if ((*sp)->update_data_size_and_addralign())
11321         {
11322           // Update data size of stub table owner.
11323           Arm_input_section<big_endian>* owner = (*sp)->owner();
11324           uint64_t address = owner->address();
11325           off_t offset = owner->offset();
11326           owner->reset_address_and_file_offset();
11327           owner->set_address_and_file_offset(address, offset);
11328
11329           sections_needing_adjustment.insert(owner->output_section());
11330           any_stub_table_changed = true;
11331         }
11332     }
11333
11334   // Output_section_data::output_section() returns a const pointer but we
11335   // need to update output sections, so we record all output sections needing
11336   // update above and scan the sections here to find out what sections need
11337   // to be updated.
11338   for(Layout::Section_list::const_iterator p = layout->section_list().begin();
11339       p != layout->section_list().end();
11340       ++p)
11341     {
11342       if (sections_needing_adjustment.find(*p)
11343           != sections_needing_adjustment.end())
11344         (*p)->set_section_offsets_need_adjustment();
11345     }
11346
11347   // Stop relaxation if no EXIDX fix-up and no stub table change.
11348   bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11349
11350   // Finalize the stubs in the last relaxation pass.
11351   if (!continue_relaxation)
11352     {
11353       for (Stub_table_iterator sp = this->stub_tables_.begin();
11354            (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11355             ++sp)
11356         (*sp)->finalize_stubs();
11357
11358       // Update output local symbol counts of objects if necessary.
11359       for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11360            op != input_objects->relobj_end();
11361            ++op)
11362         {
11363           Arm_relobj<big_endian>* arm_relobj =
11364             Arm_relobj<big_endian>::as_arm_relobj(*op);
11365
11366           // Update output local symbol counts.  We need to discard local
11367           // symbols defined in parts of input sections that are discarded by
11368           // relaxation.
11369           if (arm_relobj->output_local_symbol_count_needs_update())
11370             arm_relobj->update_output_local_symbol_count();
11371         }
11372     }
11373
11374   return continue_relaxation;
11375 }
11376
11377 // Relocate a stub.
11378
11379 template<bool big_endian>
11380 void
11381 Target_arm<big_endian>::relocate_stub(
11382     Stub* stub,
11383     const Relocate_info<32, big_endian>* relinfo,
11384     Output_section* output_section,
11385     unsigned char* view,
11386     Arm_address address,
11387     section_size_type view_size)
11388 {
11389   Relocate relocate;
11390   const Stub_template* stub_template = stub->stub_template();
11391   for (size_t i = 0; i < stub_template->reloc_count(); i++)
11392     {
11393       size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11394       const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11395
11396       unsigned int r_type = insn->r_type();
11397       section_size_type reloc_offset = stub_template->reloc_offset(i);
11398       section_size_type reloc_size = insn->size();
11399       gold_assert(reloc_offset + reloc_size <= view_size);
11400
11401       // This is the address of the stub destination.
11402       Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11403       Symbol_value<32> symval;
11404       symval.set_output_value(target);
11405
11406       // Synthesize a fake reloc just in case.  We don't have a symbol so
11407       // we use 0.
11408       unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11409       memset(reloc_buffer, 0, sizeof(reloc_buffer));
11410       elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11411       reloc_write.put_r_offset(reloc_offset);
11412       reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11413       elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11414
11415       relocate.relocate(relinfo, this, output_section,
11416                         this->fake_relnum_for_stubs, rel, r_type,
11417                         NULL, &symval, view + reloc_offset,
11418                         address + reloc_offset, reloc_size);
11419     }
11420 }
11421
11422 // Determine whether an object attribute tag takes an integer, a
11423 // string or both.
11424
11425 template<bool big_endian>
11426 int
11427 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11428 {
11429   if (tag == Object_attribute::Tag_compatibility)
11430     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11431             | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11432   else if (tag == elfcpp::Tag_nodefaults)
11433     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11434             | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11435   else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11436     return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11437   else if (tag < 32)
11438     return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11439   else
11440     return ((tag & 1) != 0
11441             ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11442             : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11443 }
11444
11445 // Reorder attributes.
11446 //
11447 // The ABI defines that Tag_conformance should be emitted first, and that
11448 // Tag_nodefaults should be second (if either is defined).  This sets those
11449 // two positions, and bumps up the position of all the remaining tags to
11450 // compensate.
11451
11452 template<bool big_endian>
11453 int
11454 Target_arm<big_endian>::do_attributes_order(int num) const
11455 {
11456   // Reorder the known object attributes in output.  We want to move
11457   // Tag_conformance to position 4 and Tag_conformance to position 5
11458   // and shift eveything between 4 .. Tag_conformance - 1 to make room.
11459   if (num == 4)
11460     return elfcpp::Tag_conformance;
11461   if (num == 5)
11462     return elfcpp::Tag_nodefaults;
11463   if ((num - 2) < elfcpp::Tag_nodefaults)
11464     return num - 2;
11465   if ((num - 1) < elfcpp::Tag_conformance)
11466     return num - 1;
11467   return num;
11468 }
11469
11470 // Scan a span of THUMB code for Cortex-A8 erratum.
11471
11472 template<bool big_endian>
11473 void
11474 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11475     Arm_relobj<big_endian>* arm_relobj,
11476     unsigned int shndx,
11477     section_size_type span_start,
11478     section_size_type span_end,
11479     const unsigned char* view,
11480     Arm_address address)
11481 {
11482   // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11483   //
11484   // The opcode is BLX.W, BL.W, B.W, Bcc.W
11485   // The branch target is in the same 4KB region as the
11486   // first half of the branch.
11487   // The instruction before the branch is a 32-bit
11488   // length non-branch instruction.
11489   section_size_type i = span_start;
11490   bool last_was_32bit = false;
11491   bool last_was_branch = false;
11492   while (i < span_end)
11493     {
11494       typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11495       const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11496       uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11497       bool is_blx = false, is_b = false;
11498       bool is_bl = false, is_bcc = false;
11499
11500       bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11501       if (insn_32bit)
11502         {
11503           // Load the rest of the insn (in manual-friendly order).
11504           insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11505
11506           // Encoding T4: B<c>.W.
11507           is_b = (insn & 0xf800d000U) == 0xf0009000U;
11508           // Encoding T1: BL<c>.W.
11509           is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11510           // Encoding T2: BLX<c>.W.
11511           is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11512           // Encoding T3: B<c>.W (not permitted in IT block).
11513           is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11514                     && (insn & 0x07f00000U) != 0x03800000U);
11515         }
11516
11517       bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11518                            
11519       // If this instruction is a 32-bit THUMB branch that crosses a 4K
11520       // page boundary and it follows 32-bit non-branch instruction,
11521       // we need to work around.
11522       if (is_32bit_branch
11523           && ((address + i) & 0xfffU) == 0xffeU
11524           && last_was_32bit
11525           && !last_was_branch)
11526         {
11527           // Check to see if there is a relocation stub for this branch.
11528           bool force_target_arm = false;
11529           bool force_target_thumb = false;
11530           const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11531           Cortex_a8_relocs_info::const_iterator p =
11532             this->cortex_a8_relocs_info_.find(address + i);
11533
11534           if (p != this->cortex_a8_relocs_info_.end())
11535             {
11536               cortex_a8_reloc = p->second;
11537               bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11538
11539               if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11540                   && !target_is_thumb)
11541                 force_target_arm = true;
11542               else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11543                        && target_is_thumb)
11544                 force_target_thumb = true;
11545             }
11546
11547           off_t offset;
11548           Stub_type stub_type = arm_stub_none;
11549
11550           // Check if we have an offending branch instruction.
11551           uint16_t upper_insn = (insn >> 16) & 0xffffU;
11552           uint16_t lower_insn = insn & 0xffffU;
11553           typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
11554
11555           if (cortex_a8_reloc != NULL
11556               && cortex_a8_reloc->reloc_stub() != NULL)
11557             // We've already made a stub for this instruction, e.g.
11558             // it's a long branch or a Thumb->ARM stub.  Assume that
11559             // stub will suffice to work around the A8 erratum (see
11560             // setting of always_after_branch above).
11561             ;
11562           else if (is_bcc)
11563             {
11564               offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11565                                                               lower_insn);
11566               stub_type = arm_stub_a8_veneer_b_cond;
11567             }
11568           else if (is_b || is_bl || is_blx)
11569             {
11570               offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11571                                                          lower_insn);
11572               if (is_blx)
11573                 offset &= ~3;
11574
11575               stub_type = (is_blx
11576                            ? arm_stub_a8_veneer_blx
11577                            : (is_bl
11578                               ? arm_stub_a8_veneer_bl
11579                               : arm_stub_a8_veneer_b));
11580             }
11581
11582           if (stub_type != arm_stub_none)
11583             {
11584               Arm_address pc_for_insn = address + i + 4;
11585
11586               // The original instruction is a BL, but the target is
11587               // an ARM instruction.  If we were not making a stub,
11588               // the BL would have been converted to a BLX.  Use the
11589               // BLX stub instead in that case.
11590               if (this->may_use_blx() && force_target_arm
11591                   && stub_type == arm_stub_a8_veneer_bl)
11592                 {
11593                   stub_type = arm_stub_a8_veneer_blx;
11594                   is_blx = true;
11595                   is_bl = false;
11596                 }
11597               // Conversely, if the original instruction was
11598               // BLX but the target is Thumb mode, use the BL stub.
11599               else if (force_target_thumb
11600                        && stub_type == arm_stub_a8_veneer_blx)
11601                 {
11602                   stub_type = arm_stub_a8_veneer_bl;
11603                   is_blx = false;
11604                   is_bl = true;
11605                 }
11606
11607               if (is_blx)
11608                 pc_for_insn &= ~3;
11609
11610               // If we found a relocation, use the proper destination,
11611               // not the offset in the (unrelocated) instruction.
11612               // Note this is always done if we switched the stub type above.
11613               if (cortex_a8_reloc != NULL)
11614                 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11615
11616               Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11617
11618               // Add a new stub if destination address in in the same page.
11619               if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11620                 {
11621                   Cortex_a8_stub* stub =
11622                     this->stub_factory_.make_cortex_a8_stub(stub_type,
11623                                                             arm_relobj, shndx,
11624                                                             address + i,
11625                                                             target, insn);
11626                   Stub_table<big_endian>* stub_table =
11627                     arm_relobj->stub_table(shndx);
11628                   gold_assert(stub_table != NULL);
11629                   stub_table->add_cortex_a8_stub(address + i, stub);
11630                 }
11631             }
11632         }
11633
11634       i += insn_32bit ? 4 : 2;
11635       last_was_32bit = insn_32bit;
11636       last_was_branch = is_32bit_branch;
11637     }
11638 }
11639
11640 // Apply the Cortex-A8 workaround.
11641
11642 template<bool big_endian>
11643 void
11644 Target_arm<big_endian>::apply_cortex_a8_workaround(
11645     const Cortex_a8_stub* stub,
11646     Arm_address stub_address,
11647     unsigned char* insn_view,
11648     Arm_address insn_address)
11649 {
11650   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11651   Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
11652   Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
11653   Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
11654   off_t branch_offset = stub_address - (insn_address + 4);
11655
11656   typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
11657   switch (stub->stub_template()->type())
11658     {
11659     case arm_stub_a8_veneer_b_cond:
11660       // For a conditional branch, we re-write it to be a uncondition
11661       // branch to the stub.  We use the THUMB-2 encoding here.
11662       upper_insn = 0xf000U;
11663       lower_insn = 0xb800U;
11664       // Fall through
11665     case arm_stub_a8_veneer_b:
11666     case arm_stub_a8_veneer_bl:
11667     case arm_stub_a8_veneer_blx:
11668       if ((lower_insn & 0x5000U) == 0x4000U)
11669         // For a BLX instruction, make sure that the relocation is
11670         // rounded up to a word boundary.  This follows the semantics of
11671         // the instruction which specifies that bit 1 of the target
11672         // address will come from bit 1 of the base address.
11673         branch_offset = (branch_offset + 2) & ~3;
11674
11675       // Put BRANCH_OFFSET back into the insn.
11676       gold_assert(!utils::has_overflow<25>(branch_offset));
11677       upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
11678       lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
11679       break;
11680
11681     default:
11682       gold_unreachable();
11683     }
11684
11685   // Put the relocated value back in the object file:
11686   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
11687   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
11688 }
11689
11690 template<bool big_endian>
11691 class Target_selector_arm : public Target_selector
11692 {
11693  public:
11694   Target_selector_arm()
11695     : Target_selector(elfcpp::EM_ARM, 32, big_endian,
11696                       (big_endian ? "elf32-bigarm" : "elf32-littlearm"))
11697   { }
11698
11699   Target*
11700   do_instantiate_target()
11701   { return new Target_arm<big_endian>(); }
11702 };
11703
11704 // Fix .ARM.exidx section coverage.
11705
11706 template<bool big_endian>
11707 void
11708 Target_arm<big_endian>::fix_exidx_coverage(
11709     Layout* layout,
11710     const Input_objects* input_objects,
11711     Arm_output_section<big_endian>* exidx_section,
11712     Symbol_table* symtab)
11713 {
11714   // We need to look at all the input sections in output in ascending
11715   // order of of output address.  We do that by building a sorted list
11716   // of output sections by addresses.  Then we looks at the output sections
11717   // in order.  The input sections in an output section are already sorted
11718   // by addresses within the output section.
11719
11720   typedef std::set<Output_section*, output_section_address_less_than>
11721       Sorted_output_section_list;
11722   Sorted_output_section_list sorted_output_sections;
11723
11724   // Find out all the output sections of input sections pointed by
11725   // EXIDX input sections.
11726   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
11727        p != input_objects->relobj_end();
11728        ++p)
11729     {
11730       Arm_relobj<big_endian>* arm_relobj =
11731         Arm_relobj<big_endian>::as_arm_relobj(*p);
11732       std::vector<unsigned int> shndx_list;
11733       arm_relobj->get_exidx_shndx_list(&shndx_list);
11734       for (size_t i = 0; i < shndx_list.size(); ++i)
11735         {
11736           const Arm_exidx_input_section* exidx_input_section =
11737             arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
11738           gold_assert(exidx_input_section != NULL);
11739           if (!exidx_input_section->has_errors())
11740             {
11741               unsigned int text_shndx = exidx_input_section->link();
11742               Output_section* os = arm_relobj->output_section(text_shndx);
11743               if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
11744                 sorted_output_sections.insert(os);
11745             }
11746         }
11747     }
11748
11749   // Go over the output sections in ascending order of output addresses.
11750   typedef typename Arm_output_section<big_endian>::Text_section_list
11751       Text_section_list;
11752   Text_section_list sorted_text_sections;
11753   for(typename Sorted_output_section_list::iterator p =
11754         sorted_output_sections.begin();
11755       p != sorted_output_sections.end();
11756       ++p)
11757     {
11758       Arm_output_section<big_endian>* arm_output_section =
11759         Arm_output_section<big_endian>::as_arm_output_section(*p);
11760       arm_output_section->append_text_sections_to_list(&sorted_text_sections);
11761     } 
11762
11763   exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
11764                                     merge_exidx_entries());
11765 }
11766
11767 Target_selector_arm<false> target_selector_arm;
11768 Target_selector_arm<true> target_selector_armbe;
11769
11770 } // End anonymous namespace.