OSDN Git Service

2010-02-26 Doug Kwan <dougkwan@google.com>
[pf3gnuchains/pf3gnuchains4x.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 endianity-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_(), cortex_a8_stubs_(),
872       arm_v4bx_stubs_(0xf), prev_data_size_(0), prev_addralign_(1)
873   { }
874
875   ~Stub_table()
876   { }
877
878   // Owner of this stub table.
879   Arm_input_section<big_endian>*
880   owner() const
881   { return this->owner_; }
882
883   // Whether this stub table is empty.
884   bool
885   empty() const
886   {
887     return (this->reloc_stubs_.empty()
888             && this->cortex_a8_stubs_.empty()
889             && this->arm_v4bx_stubs_.empty());
890   }
891
892   // Return the current data size.
893   off_t
894   current_data_size() const
895   { return this->current_data_size_for_child(); }
896
897   // Add a STUB with using KEY.  Caller is reponsible for avoid adding
898   // if already a STUB with the same key has been added. 
899   void
900   add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key)
901   {
902     const Stub_template* stub_template = stub->stub_template();
903     gold_assert(stub_template->type() == key.stub_type());
904     this->reloc_stubs_[key] = stub;
905   }
906
907   // Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS.
908   // Caller is reponsible for avoid adding if already a STUB with the same
909   // address has been added. 
910   void
911   add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub)
912   {
913     std::pair<Arm_address, Cortex_a8_stub*> value(address, stub);
914     this->cortex_a8_stubs_.insert(value);
915   }
916
917   // Add an ARM V4BX relocation stub. A register index will be retrieved
918   // from the stub.
919   void
920   add_arm_v4bx_stub(Arm_v4bx_stub* stub)
921   {
922     gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL);
923     this->arm_v4bx_stubs_[stub->reg()] = stub;
924   }
925
926   // Remove all Cortex-A8 stubs.
927   void
928   remove_all_cortex_a8_stubs();
929
930   // Look up a relocation stub using KEY.  Return NULL if there is none.
931   Reloc_stub*
932   find_reloc_stub(const Reloc_stub::Key& key) const
933   {
934     typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
935     return (p != this->reloc_stubs_.end()) ? p->second : NULL;
936   }
937
938   // Look up an arm v4bx relocation stub using the register index.
939   // Return NULL if there is none.
940   Arm_v4bx_stub*
941   find_arm_v4bx_stub(const uint32_t reg) const
942   {
943     gold_assert(reg < 0xf);
944     return this->arm_v4bx_stubs_[reg];
945   }
946
947   // Relocate stubs in this stub table.
948   void
949   relocate_stubs(const Relocate_info<32, big_endian>*,
950                  Target_arm<big_endian>*, Output_section*,
951                  unsigned char*, Arm_address, section_size_type);
952
953   // Update data size and alignment at the end of a relaxation pass.  Return
954   // true if either data size or alignment is different from that of the
955   // previous relaxation pass.
956   bool
957   update_data_size_and_addralign();
958
959   // Finalize stubs.  Set the offsets of all stubs and mark input sections
960   // needing the Cortex-A8 workaround.
961   void
962   finalize_stubs();
963   
964   // Apply Cortex-A8 workaround to an address range.
965   void
966   apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*,
967                                               unsigned char*, Arm_address,
968                                               section_size_type);
969
970  protected:
971   // Write out section contents.
972   void
973   do_write(Output_file*);
974  
975   // Return the required alignment.
976   uint64_t
977   do_addralign() const
978   { return this->prev_addralign_; }
979
980   // Reset address and file offset.
981   void
982   do_reset_address_and_file_offset()
983   { this->set_current_data_size_for_child(this->prev_data_size_); }
984
985   // Set final data size.
986   void
987   set_final_data_size()
988   { this->set_data_size(this->current_data_size()); }
989   
990  private:
991   // Relocate one stub.
992   void
993   relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
994                 Target_arm<big_endian>*, Output_section*,
995                 unsigned char*, Arm_address, section_size_type);
996
997   // Unordered map of relocation stubs.
998   typedef
999     Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
1000                   Reloc_stub::Key::equal_to>
1001     Reloc_stub_map;
1002
1003   // List of Cortex-A8 stubs ordered by addresses of branches being
1004   // fixed up in output.
1005   typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list;
1006   // List of Arm V4BX relocation stubs ordered by associated registers.
1007   typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list;
1008
1009   // Owner of this stub table.
1010   Arm_input_section<big_endian>* owner_;
1011   // The relocation stubs.
1012   Reloc_stub_map reloc_stubs_;
1013   // The cortex_a8_stubs.
1014   Cortex_a8_stub_list cortex_a8_stubs_;
1015   // The Arm V4BX relocation stubs.
1016   Arm_v4bx_stub_list arm_v4bx_stubs_;
1017   // data size of this in the previous pass.
1018   off_t prev_data_size_;
1019   // address alignment of this in the previous pass.
1020   uint64_t prev_addralign_;
1021 };
1022
1023 // Arm_exidx_cantunwind class.  This represents an EXIDX_CANTUNWIND entry
1024 // we add to the end of an EXIDX input section that goes into the output.
1025
1026 class Arm_exidx_cantunwind : public Output_section_data
1027 {
1028  public:
1029   Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
1030     : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
1031   { }
1032
1033   // Return the object containing the section pointed by this.
1034   Relobj*
1035   relobj() const
1036   { return this->relobj_; }
1037
1038   // Return the section index of the section pointed by this.
1039   unsigned int
1040   shndx() const
1041   { return this->shndx_; }
1042
1043  protected:
1044   void
1045   do_write(Output_file* of)
1046   {
1047     if (parameters->target().is_big_endian())
1048       this->do_fixed_endian_write<true>(of);
1049     else
1050       this->do_fixed_endian_write<false>(of);
1051   }
1052
1053  private:
1054   // Implement do_write for a given endianity.
1055   template<bool big_endian>
1056   void inline
1057   do_fixed_endian_write(Output_file*);
1058   
1059   // The object containing the section pointed by this.
1060   Relobj* relobj_;
1061   // The section index of the section pointed by this.
1062   unsigned int shndx_;
1063 };
1064
1065 // During EXIDX coverage fix-up, we compact an EXIDX section.  The
1066 // Offset map is used to map input section offset within the EXIDX section
1067 // to the output offset from the start of this EXIDX section. 
1068
1069 typedef std::map<section_offset_type, section_offset_type>
1070         Arm_exidx_section_offset_map;
1071
1072 // Arm_exidx_merged_section class.  This represents an EXIDX input section
1073 // with some of its entries merged.
1074
1075 class Arm_exidx_merged_section : public Output_relaxed_input_section
1076 {
1077  public:
1078   // Constructor for Arm_exidx_merged_section.
1079   // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
1080   // SECTION_OFFSET_MAP points to a section offset map describing how
1081   // parts of the input section are mapped to output.  DELETED_BYTES is
1082   // the number of bytes deleted from the EXIDX input section.
1083   Arm_exidx_merged_section(
1084       const Arm_exidx_input_section& exidx_input_section,
1085       const Arm_exidx_section_offset_map& section_offset_map,
1086       uint32_t deleted_bytes);
1087
1088   // Return the original EXIDX input section.
1089   const Arm_exidx_input_section&
1090   exidx_input_section() const
1091   { return this->exidx_input_section_; }
1092
1093   // Return the section offset map.
1094   const Arm_exidx_section_offset_map&
1095   section_offset_map() const
1096   { return this->section_offset_map_; }
1097
1098  protected:
1099   // Write merged section into file OF.
1100   void
1101   do_write(Output_file* of);
1102
1103   bool
1104   do_output_offset(const Relobj*, unsigned int, section_offset_type,
1105                   section_offset_type*) const;
1106
1107  private:
1108   // Original EXIDX input section.
1109   const Arm_exidx_input_section& exidx_input_section_;
1110   // Section offset map.
1111   const Arm_exidx_section_offset_map& section_offset_map_;
1112 };
1113
1114 // A class to wrap an ordinary input section containing executable code.
1115
1116 template<bool big_endian>
1117 class Arm_input_section : public Output_relaxed_input_section
1118 {
1119  public:
1120   Arm_input_section(Relobj* relobj, unsigned int shndx)
1121     : Output_relaxed_input_section(relobj, shndx, 1),
1122       original_addralign_(1), original_size_(0), stub_table_(NULL)
1123   { }
1124
1125   ~Arm_input_section()
1126   { }
1127
1128   // Initialize.
1129   void
1130   init();
1131   
1132   // Whether this is a stub table owner.
1133   bool
1134   is_stub_table_owner() const
1135   { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
1136
1137   // Return the stub table.
1138   Stub_table<big_endian>*
1139   stub_table() const
1140   { return this->stub_table_; }
1141
1142   // Set the stub_table.
1143   void
1144   set_stub_table(Stub_table<big_endian>* stub_table)
1145   { this->stub_table_ = stub_table; }
1146
1147   // Downcast a base pointer to an Arm_input_section pointer.  This is
1148   // not type-safe but we only use Arm_input_section not the base class.
1149   static Arm_input_section<big_endian>*
1150   as_arm_input_section(Output_relaxed_input_section* poris)
1151   { return static_cast<Arm_input_section<big_endian>*>(poris); }
1152
1153  protected:
1154   // Write data to output file.
1155   void
1156   do_write(Output_file*);
1157
1158   // Return required alignment of this.
1159   uint64_t
1160   do_addralign() const
1161   {
1162     if (this->is_stub_table_owner())
1163       return std::max(this->stub_table_->addralign(),
1164                       this->original_addralign_);
1165     else
1166       return this->original_addralign_;
1167   }
1168
1169   // Finalize data size.
1170   void
1171   set_final_data_size();
1172
1173   // Reset address and file offset.
1174   void
1175   do_reset_address_and_file_offset();
1176
1177   // Output offset.
1178   bool
1179   do_output_offset(const Relobj* object, unsigned int shndx,
1180                    section_offset_type offset,
1181                    section_offset_type* poutput) const
1182   {
1183     if ((object == this->relobj())
1184         && (shndx == this->shndx())
1185         && (offset >= 0)
1186         && (convert_types<uint64_t, section_offset_type>(offset)
1187             <= this->original_size_))
1188       {
1189         *poutput = offset;
1190         return true;
1191       }
1192     else
1193       return false;
1194   }
1195
1196  private:
1197   // Copying is not allowed.
1198   Arm_input_section(const Arm_input_section&);
1199   Arm_input_section& operator=(const Arm_input_section&);
1200
1201   // Address alignment of the original input section.
1202   uint64_t original_addralign_;
1203   // Section size of the original input section.
1204   uint64_t original_size_;
1205   // Stub table.
1206   Stub_table<big_endian>* stub_table_;
1207 };
1208
1209 // Arm_exidx_fixup class.  This is used to define a number of methods
1210 // and keep states for fixing up EXIDX coverage.
1211
1212 class Arm_exidx_fixup
1213 {
1214  public:
1215   Arm_exidx_fixup(Output_section* exidx_output_section)
1216     : exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE),
1217       last_inlined_entry_(0), last_input_section_(NULL),
1218       section_offset_map_(NULL), first_output_text_section_(NULL)
1219   { }
1220
1221   ~Arm_exidx_fixup()
1222   { delete this->section_offset_map_; }
1223
1224   // Process an EXIDX section for entry merging.  Return  number of bytes to
1225   // be deleted in output.  If parts of the input EXIDX section are merged
1226   // a heap allocated Arm_exidx_section_offset_map is store in the located
1227   // PSECTION_OFFSET_MAP.  The caller owns the map and is reponsible for
1228   // releasing it.
1229   template<bool big_endian>
1230   uint32_t
1231   process_exidx_section(const Arm_exidx_input_section* exidx_input_section,
1232                         Arm_exidx_section_offset_map** psection_offset_map);
1233   
1234   // Append an EXIDX_CANTUNWIND entry pointing at the end of the last
1235   // input section, if there is not one already.
1236   void
1237   add_exidx_cantunwind_as_needed();
1238
1239   // Return the output section for the text section which is linked to the
1240   // first exidx input in output.
1241   Output_section*
1242   first_output_text_section() const
1243   { return this->first_output_text_section_; }
1244
1245  private:
1246   // Copying is not allowed.
1247   Arm_exidx_fixup(const Arm_exidx_fixup&);
1248   Arm_exidx_fixup& operator=(const Arm_exidx_fixup&);
1249
1250   // Type of EXIDX unwind entry.
1251   enum Unwind_type
1252   {
1253     // No type.
1254     UT_NONE,
1255     // EXIDX_CANTUNWIND.
1256     UT_EXIDX_CANTUNWIND,
1257     // Inlined entry.
1258     UT_INLINED_ENTRY,
1259     // Normal entry.
1260     UT_NORMAL_ENTRY,
1261   };
1262
1263   // Process an EXIDX entry.  We only care about the second word of the
1264   // entry.  Return true if the entry can be deleted.
1265   bool
1266   process_exidx_entry(uint32_t second_word);
1267
1268   // Update the current section offset map during EXIDX section fix-up.
1269   // If there is no map, create one.  INPUT_OFFSET is the offset of a
1270   // reference point, DELETED_BYTES is the number of deleted by in the
1271   // section so far.  If DELETE_ENTRY is true, the reference point and
1272   // all offsets after the previous reference point are discarded.
1273   void
1274   update_offset_map(section_offset_type input_offset,
1275                     section_size_type deleted_bytes, bool delete_entry);
1276
1277   // EXIDX output section.
1278   Output_section* exidx_output_section_;
1279   // Unwind type of the last EXIDX entry processed.
1280   Unwind_type last_unwind_type_;
1281   // Last seen inlined EXIDX entry.
1282   uint32_t last_inlined_entry_;
1283   // Last processed EXIDX input section.
1284   const Arm_exidx_input_section* last_input_section_;
1285   // Section offset map created in process_exidx_section.
1286   Arm_exidx_section_offset_map* section_offset_map_;
1287   // Output section for the text section which is linked to the first exidx
1288   // input in output.
1289   Output_section* first_output_text_section_;
1290 };
1291
1292 // Arm output section class.  This is defined mainly to add a number of
1293 // stub generation methods.
1294
1295 template<bool big_endian>
1296 class Arm_output_section : public Output_section
1297 {
1298  public:
1299   typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list;
1300
1301   Arm_output_section(const char* name, elfcpp::Elf_Word type,
1302                      elfcpp::Elf_Xword flags)
1303     : Output_section(name, type, flags)
1304   { }
1305
1306   ~Arm_output_section()
1307   { }
1308   
1309   // Group input sections for stub generation.
1310   void
1311   group_sections(section_size_type, bool, Target_arm<big_endian>*);
1312
1313   // Downcast a base pointer to an Arm_output_section pointer.  This is
1314   // not type-safe but we only use Arm_output_section not the base class.
1315   static Arm_output_section<big_endian>*
1316   as_arm_output_section(Output_section* os)
1317   { return static_cast<Arm_output_section<big_endian>*>(os); }
1318
1319   // Append all input text sections in this into LIST.
1320   void
1321   append_text_sections_to_list(Text_section_list* list);
1322
1323   // Fix EXIDX coverage of this EXIDX output section.  SORTED_TEXT_SECTION
1324   // is a list of text input sections sorted in ascending order of their
1325   // output addresses.
1326   void
1327   fix_exidx_coverage(Layout* layout,
1328                      const Text_section_list& sorted_text_section,
1329                      Symbol_table* symtab);
1330
1331  private:
1332   // For convenience.
1333   typedef Output_section::Input_section Input_section;
1334   typedef Output_section::Input_section_list Input_section_list;
1335
1336   // Create a stub group.
1337   void create_stub_group(Input_section_list::const_iterator,
1338                          Input_section_list::const_iterator,
1339                          Input_section_list::const_iterator,
1340                          Target_arm<big_endian>*,
1341                          std::vector<Output_relaxed_input_section*>*);
1342 };
1343
1344 // Arm_exidx_input_section class.  This represents an EXIDX input section.
1345
1346 class Arm_exidx_input_section
1347 {
1348  public:
1349   static const section_offset_type invalid_offset =
1350     static_cast<section_offset_type>(-1);
1351
1352   Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1353                           unsigned int link, uint32_t size, uint32_t addralign)
1354     : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1355       addralign_(addralign)
1356   { }
1357
1358   ~Arm_exidx_input_section()
1359   { }
1360         
1361   // Accessors:  This is a read-only class.
1362
1363   // Return the object containing this EXIDX input section.
1364   Relobj*
1365   relobj() const
1366   { return this->relobj_; }
1367
1368   // Return the section index of this EXIDX input section.
1369   unsigned int
1370   shndx() const
1371   { return this->shndx_; }
1372
1373   // Return the section index of linked text section in the same object.
1374   unsigned int
1375   link() const
1376   { return this->link_; }
1377
1378   // Return size of the EXIDX input section.
1379   uint32_t
1380   size() const
1381   { return this->size_; }
1382
1383   // Reutnr address alignment of EXIDX input section.
1384   uint32_t
1385   addralign() const
1386   { return this->addralign_; }
1387
1388  private:
1389   // Object containing this.
1390   Relobj* relobj_;
1391   // Section index of this.
1392   unsigned int shndx_;
1393   // text section linked to this in the same object.
1394   unsigned int link_;
1395   // Size of this.  For ARM 32-bit is sufficient.
1396   uint32_t size_;
1397   // Address alignment of this.  For ARM 32-bit is sufficient.
1398   uint32_t addralign_;
1399 };
1400
1401 // Arm_relobj class.
1402
1403 template<bool big_endian>
1404 class Arm_relobj : public Sized_relobj<32, big_endian>
1405 {
1406  public:
1407   static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1408
1409   Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1410              const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1411     : Sized_relobj<32, big_endian>(name, input_file, offset, ehdr),
1412       stub_tables_(), local_symbol_is_thumb_function_(),
1413       attributes_section_data_(NULL), mapping_symbols_info_(),
1414       section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1415       output_local_symbol_count_needs_update_(false)
1416   { }
1417
1418   ~Arm_relobj()
1419   { delete this->attributes_section_data_; }
1420  
1421   // Return the stub table of the SHNDX-th section if there is one.
1422   Stub_table<big_endian>*
1423   stub_table(unsigned int shndx) const
1424   {
1425     gold_assert(shndx < this->stub_tables_.size());
1426     return this->stub_tables_[shndx];
1427   }
1428
1429   // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1430   void
1431   set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1432   {
1433     gold_assert(shndx < this->stub_tables_.size());
1434     this->stub_tables_[shndx] = stub_table;
1435   }
1436
1437   // Whether a local symbol is a THUMB function.  R_SYM is the symbol table
1438   // index.  This is only valid after do_count_local_symbol is called.
1439   bool
1440   local_symbol_is_thumb_function(unsigned int r_sym) const
1441   {
1442     gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1443     return this->local_symbol_is_thumb_function_[r_sym];
1444   }
1445   
1446   // Scan all relocation sections for stub generation.
1447   void
1448   scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1449                           const Layout*);
1450
1451   // Convert regular input section with index SHNDX to a relaxed section.
1452   void
1453   convert_input_section_to_relaxed_section(unsigned shndx)
1454   {
1455     // The stubs have relocations and we need to process them after writing
1456     // out the stubs.  So relocation now must follow section write.
1457     this->set_section_offset(shndx, -1ULL);
1458     this->set_relocs_must_follow_section_writes();
1459   }
1460
1461   // Downcast a base pointer to an Arm_relobj pointer.  This is
1462   // not type-safe but we only use Arm_relobj not the base class.
1463   static Arm_relobj<big_endian>*
1464   as_arm_relobj(Relobj* relobj)
1465   { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1466
1467   // Processor-specific flags in ELF file header.  This is valid only after
1468   // reading symbols.
1469   elfcpp::Elf_Word
1470   processor_specific_flags() const
1471   { return this->processor_specific_flags_; }
1472
1473   // Attribute section data  This is the contents of the .ARM.attribute section
1474   // if there is one.
1475   const Attributes_section_data*
1476   attributes_section_data() const
1477   { return this->attributes_section_data_; }
1478
1479   // Mapping symbol location.
1480   typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1481
1482   // Functor for STL container.
1483   struct Mapping_symbol_position_less
1484   {
1485     bool
1486     operator()(const Mapping_symbol_position& p1,
1487                const Mapping_symbol_position& p2) const
1488     {
1489       return (p1.first < p2.first
1490               || (p1.first == p2.first && p1.second < p2.second));
1491     }
1492   };
1493   
1494   // We only care about the first character of a mapping symbol, so
1495   // we only store that instead of the whole symbol name.
1496   typedef std::map<Mapping_symbol_position, char,
1497                    Mapping_symbol_position_less> Mapping_symbols_info;
1498
1499   // Whether a section contains any Cortex-A8 workaround.
1500   bool
1501   section_has_cortex_a8_workaround(unsigned int shndx) const
1502   { 
1503     return (this->section_has_cortex_a8_workaround_ != NULL
1504             && (*this->section_has_cortex_a8_workaround_)[shndx]);
1505   }
1506   
1507   // Mark a section that has Cortex-A8 workaround.
1508   void
1509   mark_section_for_cortex_a8_workaround(unsigned int shndx)
1510   {
1511     if (this->section_has_cortex_a8_workaround_ == NULL)
1512       this->section_has_cortex_a8_workaround_ =
1513         new std::vector<bool>(this->shnum(), false);
1514     (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1515   }
1516
1517   // Return the EXIDX section of an text section with index SHNDX or NULL
1518   // if the text section has no associated EXIDX section.
1519   const Arm_exidx_input_section*
1520   exidx_input_section_by_link(unsigned int shndx) const
1521   {
1522     Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1523     return ((p != this->exidx_section_map_.end()
1524              && p->second->link() == shndx)
1525             ? p->second
1526             : NULL);
1527   }
1528
1529   // Return the EXIDX section with index SHNDX or NULL if there is none.
1530   const Arm_exidx_input_section*
1531   exidx_input_section_by_shndx(unsigned shndx) const
1532   {
1533     Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1534     return ((p != this->exidx_section_map_.end()
1535              && p->second->shndx() == shndx)
1536             ? p->second
1537             : NULL);
1538   }
1539
1540   // Whether output local symbol count needs updating.
1541   bool
1542   output_local_symbol_count_needs_update() const
1543   { return this->output_local_symbol_count_needs_update_; }
1544
1545   // Set output_local_symbol_count_needs_update flag to be true.
1546   void
1547   set_output_local_symbol_count_needs_update()
1548   { this->output_local_symbol_count_needs_update_ = true; }
1549   
1550   // Update output local symbol count at the end of relaxation.
1551   void
1552   update_output_local_symbol_count();
1553
1554  protected:
1555   // Post constructor setup.
1556   void
1557   do_setup()
1558   {
1559     // Call parent's setup method.
1560     Sized_relobj<32, big_endian>::do_setup();
1561
1562     // Initialize look-up tables.
1563     Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1564     this->stub_tables_.swap(empty_stub_table_list);
1565   }
1566
1567   // Count the local symbols.
1568   void
1569   do_count_local_symbols(Stringpool_template<char>*,
1570                          Stringpool_template<char>*);
1571
1572   void
1573   do_relocate_sections(const Symbol_table* symtab, const Layout* layout,
1574                        const unsigned char* pshdrs,
1575                        typename Sized_relobj<32, big_endian>::Views* pivews);
1576
1577   // Read the symbol information.
1578   void
1579   do_read_symbols(Read_symbols_data* sd);
1580
1581   // Process relocs for garbage collection.
1582   void
1583   do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1584
1585  private:
1586
1587   // Whether a section needs to be scanned for relocation stubs.
1588   bool
1589   section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1590                                     const Relobj::Output_sections&,
1591                                     const Symbol_table *, const unsigned char*);
1592
1593   // Whether a section is a scannable text section.
1594   bool
1595   section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1596                        const Output_section*, const Symbol_table *);
1597
1598   // Whether a section needs to be scanned for the Cortex-A8 erratum.
1599   bool
1600   section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1601                                         unsigned int, Output_section*,
1602                                         const Symbol_table *);
1603
1604   // Scan a section for the Cortex-A8 erratum.
1605   void
1606   scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1607                                      unsigned int, Output_section*,
1608                                      Target_arm<big_endian>*);
1609
1610   // Find the linked text section of an EXIDX section by looking at the
1611   // first reloction of the EXIDX section.  PSHDR points to the section
1612   // headers of a relocation section and PSYMS points to the local symbols.
1613   // PSHNDX points to a location storing the text section index if found.
1614   // Return whether we can find the linked section.
1615   bool
1616   find_linked_text_section(const unsigned char* pshdr,
1617                            const unsigned char* psyms, unsigned int* pshndx);
1618
1619   //
1620   // Make a new Arm_exidx_input_section object for EXIDX section with
1621   // index SHNDX and section header SHDR.  TEXT_SHNDX is the section
1622   // index of the linked text section.
1623   void
1624   make_exidx_input_section(unsigned int shndx,
1625                            const elfcpp::Shdr<32, big_endian>& shdr,
1626                            unsigned int text_shndx);
1627
1628   // Return the output address of either a plain input section or a
1629   // relaxed input section.  SHNDX is the section index.
1630   Arm_address
1631   simple_input_section_output_address(unsigned int, Output_section*);
1632
1633   typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1634   typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1635     Exidx_section_map;
1636
1637   // List of stub tables.
1638   Stub_table_list stub_tables_;
1639   // Bit vector to tell if a local symbol is a thumb function or not.
1640   // This is only valid after do_count_local_symbol is called.
1641   std::vector<bool> local_symbol_is_thumb_function_;
1642   // processor-specific flags in ELF file header.
1643   elfcpp::Elf_Word processor_specific_flags_;
1644   // Object attributes if there is an .ARM.attributes section or NULL.
1645   Attributes_section_data* attributes_section_data_;
1646   // Mapping symbols information.
1647   Mapping_symbols_info mapping_symbols_info_;
1648   // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1649   std::vector<bool>* section_has_cortex_a8_workaround_;
1650   // Map a text section to its associated .ARM.exidx section, if there is one.
1651   Exidx_section_map exidx_section_map_;
1652   // Whether output local symbol count needs updating.
1653   bool output_local_symbol_count_needs_update_;
1654 };
1655
1656 // Arm_dynobj class.
1657
1658 template<bool big_endian>
1659 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1660 {
1661  public:
1662   Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1663              const elfcpp::Ehdr<32, big_endian>& ehdr)
1664     : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1665       processor_specific_flags_(0), attributes_section_data_(NULL)
1666   { }
1667  
1668   ~Arm_dynobj()
1669   { delete this->attributes_section_data_; }
1670
1671   // Downcast a base pointer to an Arm_relobj pointer.  This is
1672   // not type-safe but we only use Arm_relobj not the base class.
1673   static Arm_dynobj<big_endian>*
1674   as_arm_dynobj(Dynobj* dynobj)
1675   { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1676
1677   // Processor-specific flags in ELF file header.  This is valid only after
1678   // reading symbols.
1679   elfcpp::Elf_Word
1680   processor_specific_flags() const
1681   { return this->processor_specific_flags_; }
1682
1683   // Attributes section data.
1684   const Attributes_section_data*
1685   attributes_section_data() const
1686   { return this->attributes_section_data_; }
1687
1688  protected:
1689   // Read the symbol information.
1690   void
1691   do_read_symbols(Read_symbols_data* sd);
1692
1693  private:
1694   // processor-specific flags in ELF file header.
1695   elfcpp::Elf_Word processor_specific_flags_;
1696   // Object attributes if there is an .ARM.attributes section or NULL.
1697   Attributes_section_data* attributes_section_data_;
1698 };
1699
1700 // Functor to read reloc addends during stub generation.
1701
1702 template<int sh_type, bool big_endian>
1703 struct Stub_addend_reader
1704 {
1705   // Return the addend for a relocation of a particular type.  Depending
1706   // on whether this is a REL or RELA relocation, read the addend from a
1707   // view or from a Reloc object.
1708   elfcpp::Elf_types<32>::Elf_Swxword
1709   operator()(
1710     unsigned int /* r_type */,
1711     const unsigned char* /* view */,
1712     const typename Reloc_types<sh_type,
1713                                32, big_endian>::Reloc& /* reloc */) const;
1714 };
1715
1716 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1717
1718 template<bool big_endian>
1719 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1720 {
1721   elfcpp::Elf_types<32>::Elf_Swxword
1722   operator()(
1723     unsigned int,
1724     const unsigned char*,
1725     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1726 };
1727
1728 // Specialized Stub_addend_reader for RELA type relocation sections.
1729 // We currently do not handle RELA type relocation sections but it is trivial
1730 // to implement the addend reader.  This is provided for completeness and to
1731 // make it easier to add support for RELA relocation sections in the future.
1732
1733 template<bool big_endian>
1734 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1735 {
1736   elfcpp::Elf_types<32>::Elf_Swxword
1737   operator()(
1738     unsigned int,
1739     const unsigned char*,
1740     const typename Reloc_types<elfcpp::SHT_RELA, 32,
1741                                big_endian>::Reloc& reloc) const
1742   { return reloc.get_r_addend(); }
1743 };
1744
1745 // Cortex_a8_reloc class.  We keep record of relocation that may need
1746 // the Cortex-A8 erratum workaround.
1747
1748 class Cortex_a8_reloc
1749 {
1750  public:
1751   Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1752                   Arm_address destination)
1753     : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1754   { }
1755
1756   ~Cortex_a8_reloc()
1757   { }
1758
1759   // Accessors:  This is a read-only class.
1760   
1761   // Return the relocation stub associated with this relocation if there is
1762   // one.
1763   const Reloc_stub*
1764   reloc_stub() const
1765   { return this->reloc_stub_; } 
1766   
1767   // Return the relocation type.
1768   unsigned int
1769   r_type() const
1770   { return this->r_type_; }
1771
1772   // Return the destination address of the relocation.  LSB stores the THUMB
1773   // bit.
1774   Arm_address
1775   destination() const
1776   { return this->destination_; }
1777
1778  private:
1779   // Associated relocation stub if there is one, or NULL.
1780   const Reloc_stub* reloc_stub_;
1781   // Relocation type.
1782   unsigned int r_type_;
1783   // Destination address of this relocation.  LSB is used to distinguish
1784   // ARM/THUMB mode.
1785   Arm_address destination_;
1786 };
1787
1788 // Arm_output_data_got class.  We derive this from Output_data_got to add
1789 // extra methods to handle TLS relocations in a static link.
1790
1791 template<bool big_endian>
1792 class Arm_output_data_got : public Output_data_got<32, big_endian>
1793 {
1794  public:
1795   Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1796     : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1797   { }
1798
1799   // Add a static entry for the GOT entry at OFFSET.  GSYM is a global
1800   // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1801   // applied in a static link.
1802   void
1803   add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1804   { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1805
1806   // Add a static reloc for the GOT entry at OFFSET.  RELOBJ is an object
1807   // defining a local symbol with INDEX.  R_TYPE is the code of a dynamic
1808   // relocation that needs to be applied in a static link.
1809   void
1810   add_static_reloc(unsigned int got_offset, unsigned int r_type,
1811                    Sized_relobj<32, big_endian>* relobj, unsigned int index)
1812   {
1813     this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1814                                                 index));
1815   }
1816
1817   // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
1818   // The first one is initialized to be 1, which is the module index for
1819   // the main executable and the second one 0.  A reloc of the type
1820   // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1821   // be applied by gold.  GSYM is a global symbol.
1822   void
1823   add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1824
1825   // Same as the above but for a local symbol in OBJECT with INDEX.
1826   void
1827   add_tls_gd32_with_static_reloc(unsigned int got_type,
1828                                  Sized_relobj<32, big_endian>* object,
1829                                  unsigned int index);
1830
1831  protected:
1832   // Write out the GOT table.
1833   void
1834   do_write(Output_file*);
1835
1836  private:
1837   // This class represent dynamic relocations that need to be applied by
1838   // gold because we are using TLS relocations in a static link.
1839   class Static_reloc
1840   {
1841    public:
1842     Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1843       : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1844     { this->u_.global.symbol = gsym; }
1845
1846     Static_reloc(unsigned int got_offset, unsigned int r_type,
1847           Sized_relobj<32, big_endian>* relobj, unsigned int index)
1848       : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1849     {
1850       this->u_.local.relobj = relobj;
1851       this->u_.local.index = index;
1852     }
1853
1854     // Return the GOT offset.
1855     unsigned int
1856     got_offset() const
1857     { return this->got_offset_; }
1858
1859     // Relocation type.
1860     unsigned int
1861     r_type() const
1862     { return this->r_type_; }
1863
1864     // Whether the symbol is global or not.
1865     bool
1866     symbol_is_global() const
1867     { return this->symbol_is_global_; }
1868
1869     // For a relocation against a global symbol, the global symbol.
1870     Symbol*
1871     symbol() const
1872     {
1873       gold_assert(this->symbol_is_global_);
1874       return this->u_.global.symbol;
1875     }
1876
1877     // For a relocation against a local symbol, the defining object.
1878     Sized_relobj<32, big_endian>*
1879     relobj() const
1880     {
1881       gold_assert(!this->symbol_is_global_);
1882       return this->u_.local.relobj;
1883     }
1884
1885     // For a relocation against a local symbol, the local symbol index.
1886     unsigned int
1887     index() const
1888     {
1889       gold_assert(!this->symbol_is_global_);
1890       return this->u_.local.index;
1891     }
1892
1893    private:
1894     // GOT offset of the entry to which this relocation is applied.
1895     unsigned int got_offset_;
1896     // Type of relocation.
1897     unsigned int r_type_;
1898     // Whether this relocation is against a global symbol.
1899     bool symbol_is_global_;
1900     // A global or local symbol.
1901     union
1902     {
1903       struct
1904       {
1905         // For a global symbol, the symbol itself.
1906         Symbol* symbol;
1907       } global;
1908       struct
1909       {
1910         // For a local symbol, the object defining object.
1911         Sized_relobj<32, big_endian>* relobj;
1912         // For a local symbol, the symbol index.
1913         unsigned int index;
1914       } local;
1915     } u_;
1916   };
1917
1918   // Symbol table of the output object.
1919   Symbol_table* symbol_table_;
1920   // Layout of the output object.
1921   Layout* layout_;
1922   // Static relocs to be applied to the GOT.
1923   std::vector<Static_reloc> static_relocs_;
1924 };
1925
1926 // Utilities for manipulating integers of up to 32-bits
1927
1928 namespace utils
1929 {
1930   // Sign extend an n-bit unsigned integer stored in an uint32_t into
1931   // an int32_t.  NO_BITS must be between 1 to 32.
1932   template<int no_bits>
1933   static inline int32_t
1934   sign_extend(uint32_t bits)
1935   {
1936     gold_assert(no_bits >= 0 && no_bits <= 32);
1937     if (no_bits == 32)
1938       return static_cast<int32_t>(bits);
1939     uint32_t mask = (~((uint32_t) 0)) >> (32 - no_bits);
1940     bits &= mask;
1941     uint32_t top_bit = 1U << (no_bits - 1);
1942     int32_t as_signed = static_cast<int32_t>(bits);
1943     return (bits & top_bit) ? as_signed + (-top_bit * 2) : as_signed;
1944   }
1945
1946   // Detects overflow of an NO_BITS integer stored in a uint32_t.
1947   template<int no_bits>
1948   static inline bool
1949   has_overflow(uint32_t bits)
1950   {
1951     gold_assert(no_bits >= 0 && no_bits <= 32);
1952     if (no_bits == 32)
1953       return false;
1954     int32_t max = (1 << (no_bits - 1)) - 1;
1955     int32_t min = -(1 << (no_bits - 1));
1956     int32_t as_signed = static_cast<int32_t>(bits);
1957     return as_signed > max || as_signed < min;
1958   }
1959
1960   // Detects overflow of an NO_BITS integer stored in a uint32_t when it
1961   // fits in the given number of bits as either a signed or unsigned value.
1962   // For example, has_signed_unsigned_overflow<8> would check
1963   // -128 <= bits <= 255
1964   template<int no_bits>
1965   static inline bool
1966   has_signed_unsigned_overflow(uint32_t bits)
1967   {
1968     gold_assert(no_bits >= 2 && no_bits <= 32);
1969     if (no_bits == 32)
1970       return false;
1971     int32_t max = static_cast<int32_t>((1U << no_bits) - 1);
1972     int32_t min = -(1 << (no_bits - 1));
1973     int32_t as_signed = static_cast<int32_t>(bits);
1974     return as_signed > max || as_signed < min;
1975   }
1976
1977   // Select bits from A and B using bits in MASK.  For each n in [0..31],
1978   // the n-th bit in the result is chosen from the n-th bits of A and B.
1979   // A zero selects A and a one selects B.
1980   static inline uint32_t
1981   bit_select(uint32_t a, uint32_t b, uint32_t mask)
1982   { return (a & ~mask) | (b & mask); }
1983 };
1984
1985 template<bool big_endian>
1986 class Target_arm : public Sized_target<32, big_endian>
1987 {
1988  public:
1989   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
1990     Reloc_section;
1991
1992   // When were are relocating a stub, we pass this as the relocation number.
1993   static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
1994
1995   Target_arm()
1996     : Sized_target<32, big_endian>(&arm_info),
1997       got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
1998       copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL), 
1999       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2000       stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2001       may_use_blx_(false), should_force_pic_veneer_(false),
2002       arm_input_section_map_(), attributes_section_data_(NULL),
2003       fix_cortex_a8_(false), cortex_a8_relocs_info_()
2004   { }
2005
2006   // Whether we can use BLX.
2007   bool
2008   may_use_blx() const
2009   { return this->may_use_blx_; }
2010
2011   // Set use-BLX flag.
2012   void
2013   set_may_use_blx(bool value)
2014   { this->may_use_blx_ = value; }
2015   
2016   // Whether we force PCI branch veneers.
2017   bool
2018   should_force_pic_veneer() const
2019   { return this->should_force_pic_veneer_; }
2020
2021   // Set PIC veneer flag.
2022   void
2023   set_should_force_pic_veneer(bool value)
2024   { this->should_force_pic_veneer_ = value; }
2025   
2026   // Whether we use THUMB-2 instructions.
2027   bool
2028   using_thumb2() const
2029   {
2030     Object_attribute* attr =
2031       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2032     int arch = attr->int_value();
2033     return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2034   }
2035
2036   // Whether we use THUMB/THUMB-2 instructions only.
2037   bool
2038   using_thumb_only() const
2039   {
2040     Object_attribute* attr =
2041       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2042     if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2043         && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2044       return false;
2045     attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2046     return attr->int_value() == 'M';
2047   }
2048
2049   // Whether we have an NOP instruction.  If not, use mov r0, r0 instead.
2050   bool
2051   may_use_arm_nop() const
2052   {
2053     Object_attribute* attr =
2054       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2055     int arch = attr->int_value();
2056     return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2057             || arch == elfcpp::TAG_CPU_ARCH_V6K
2058             || arch == elfcpp::TAG_CPU_ARCH_V7
2059             || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2060   }
2061
2062   // Whether we have THUMB-2 NOP.W instruction.
2063   bool
2064   may_use_thumb2_nop() const
2065   {
2066     Object_attribute* attr =
2067       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2068     int arch = attr->int_value();
2069     return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2070             || arch == elfcpp::TAG_CPU_ARCH_V7
2071             || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2072   }
2073   
2074   // Process the relocations to determine unreferenced sections for 
2075   // garbage collection.
2076   void
2077   gc_process_relocs(Symbol_table* symtab,
2078                     Layout* layout,
2079                     Sized_relobj<32, big_endian>* object,
2080                     unsigned int data_shndx,
2081                     unsigned int sh_type,
2082                     const unsigned char* prelocs,
2083                     size_t reloc_count,
2084                     Output_section* output_section,
2085                     bool needs_special_offset_handling,
2086                     size_t local_symbol_count,
2087                     const unsigned char* plocal_symbols);
2088
2089   // Scan the relocations to look for symbol adjustments.
2090   void
2091   scan_relocs(Symbol_table* symtab,
2092               Layout* layout,
2093               Sized_relobj<32, big_endian>* object,
2094               unsigned int data_shndx,
2095               unsigned int sh_type,
2096               const unsigned char* prelocs,
2097               size_t reloc_count,
2098               Output_section* output_section,
2099               bool needs_special_offset_handling,
2100               size_t local_symbol_count,
2101               const unsigned char* plocal_symbols);
2102
2103   // Finalize the sections.
2104   void
2105   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2106
2107   // Return the value to use for a dynamic symbol which requires special
2108   // treatment.
2109   uint64_t
2110   do_dynsym_value(const Symbol*) const;
2111
2112   // Relocate a section.
2113   void
2114   relocate_section(const Relocate_info<32, big_endian>*,
2115                    unsigned int sh_type,
2116                    const unsigned char* prelocs,
2117                    size_t reloc_count,
2118                    Output_section* output_section,
2119                    bool needs_special_offset_handling,
2120                    unsigned char* view,
2121                    Arm_address view_address,
2122                    section_size_type view_size,
2123                    const Reloc_symbol_changes*);
2124
2125   // Scan the relocs during a relocatable link.
2126   void
2127   scan_relocatable_relocs(Symbol_table* symtab,
2128                           Layout* layout,
2129                           Sized_relobj<32, big_endian>* object,
2130                           unsigned int data_shndx,
2131                           unsigned int sh_type,
2132                           const unsigned char* prelocs,
2133                           size_t reloc_count,
2134                           Output_section* output_section,
2135                           bool needs_special_offset_handling,
2136                           size_t local_symbol_count,
2137                           const unsigned char* plocal_symbols,
2138                           Relocatable_relocs*);
2139
2140   // Relocate a section during a relocatable link.
2141   void
2142   relocate_for_relocatable(const Relocate_info<32, big_endian>*,
2143                            unsigned int sh_type,
2144                            const unsigned char* prelocs,
2145                            size_t reloc_count,
2146                            Output_section* output_section,
2147                            off_t offset_in_output_section,
2148                            const Relocatable_relocs*,
2149                            unsigned char* view,
2150                            Arm_address view_address,
2151                            section_size_type view_size,
2152                            unsigned char* reloc_view,
2153                            section_size_type reloc_view_size);
2154
2155   // Return whether SYM is defined by the ABI.
2156   bool
2157   do_is_defined_by_abi(Symbol* sym) const
2158   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2159
2160   // Return whether there is a GOT section.
2161   bool
2162   has_got_section() const
2163   { return this->got_ != NULL; }
2164
2165   // Return the size of the GOT section.
2166   section_size_type
2167   got_size()
2168   {
2169     gold_assert(this->got_ != NULL);
2170     return this->got_->data_size();
2171   }
2172
2173   // Map platform-specific reloc types
2174   static unsigned int
2175   get_real_reloc_type (unsigned int r_type);
2176
2177   //
2178   // Methods to support stub-generations.
2179   //
2180   
2181   // Return the stub factory
2182   const Stub_factory&
2183   stub_factory() const
2184   { return this->stub_factory_; }
2185
2186   // Make a new Arm_input_section object.
2187   Arm_input_section<big_endian>*
2188   new_arm_input_section(Relobj*, unsigned int);
2189
2190   // Find the Arm_input_section object corresponding to the SHNDX-th input
2191   // section of RELOBJ.
2192   Arm_input_section<big_endian>*
2193   find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2194
2195   // Make a new Stub_table
2196   Stub_table<big_endian>*
2197   new_stub_table(Arm_input_section<big_endian>*);
2198
2199   // Scan a section for stub generation.
2200   void
2201   scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2202                          const unsigned char*, size_t, Output_section*,
2203                          bool, const unsigned char*, Arm_address,
2204                          section_size_type);
2205
2206   // Relocate a stub. 
2207   void
2208   relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2209                 Output_section*, unsigned char*, Arm_address,
2210                 section_size_type);
2211  
2212   // Get the default ARM target.
2213   static Target_arm<big_endian>*
2214   default_target()
2215   {
2216     gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2217                 && parameters->target().is_big_endian() == big_endian);
2218     return static_cast<Target_arm<big_endian>*>(
2219              parameters->sized_target<32, big_endian>());
2220   }
2221
2222   // Whether NAME belongs to a mapping symbol.
2223   static bool
2224   is_mapping_symbol_name(const char* name)
2225   {
2226     return (name
2227             && name[0] == '$'
2228             && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2229             && (name[2] == '\0' || name[2] == '.'));
2230   }
2231
2232   // Whether we work around the Cortex-A8 erratum.
2233   bool
2234   fix_cortex_a8() const
2235   { return this->fix_cortex_a8_; }
2236
2237   // Whether we fix R_ARM_V4BX relocation.
2238   // 0 - do not fix
2239   // 1 - replace with MOV instruction (armv4 target)
2240   // 2 - make interworking veneer (>= armv4t targets only)
2241   General_options::Fix_v4bx
2242   fix_v4bx() const
2243   { return parameters->options().fix_v4bx(); }
2244
2245   // Scan a span of THUMB code section for Cortex-A8 erratum.
2246   void
2247   scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2248                                   section_size_type, section_size_type,
2249                                   const unsigned char*, Arm_address);
2250
2251   // Apply Cortex-A8 workaround to a branch.
2252   void
2253   apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2254                              unsigned char*, Arm_address);
2255
2256  protected:
2257   // Make an ELF object.
2258   Object*
2259   do_make_elf_object(const std::string&, Input_file*, off_t,
2260                      const elfcpp::Ehdr<32, big_endian>& ehdr);
2261
2262   Object*
2263   do_make_elf_object(const std::string&, Input_file*, off_t,
2264                      const elfcpp::Ehdr<32, !big_endian>&)
2265   { gold_unreachable(); }
2266
2267   Object*
2268   do_make_elf_object(const std::string&, Input_file*, off_t,
2269                       const elfcpp::Ehdr<64, false>&)
2270   { gold_unreachable(); }
2271
2272   Object*
2273   do_make_elf_object(const std::string&, Input_file*, off_t,
2274                      const elfcpp::Ehdr<64, true>&)
2275   { gold_unreachable(); }
2276
2277   // Make an output section.
2278   Output_section*
2279   do_make_output_section(const char* name, elfcpp::Elf_Word type,
2280                          elfcpp::Elf_Xword flags)
2281   { return new Arm_output_section<big_endian>(name, type, flags); }
2282
2283   void
2284   do_adjust_elf_header(unsigned char* view, int len) const;
2285
2286   // We only need to generate stubs, and hence perform relaxation if we are
2287   // not doing relocatable linking.
2288   bool
2289   do_may_relax() const
2290   { return !parameters->options().relocatable(); }
2291
2292   bool
2293   do_relax(int, const Input_objects*, Symbol_table*, Layout*);
2294
2295   // Determine whether an object attribute tag takes an integer, a
2296   // string or both.
2297   int
2298   do_attribute_arg_type(int tag) const;
2299
2300   // Reorder tags during output.
2301   int
2302   do_attributes_order(int num) const;
2303
2304   // This is called when the target is selected as the default.
2305   void
2306   do_select_as_default_target()
2307   {
2308     // No locking is required since there should only be one default target.
2309     // We cannot have both the big-endian and little-endian ARM targets
2310     // as the default.
2311     gold_assert(arm_reloc_property_table == NULL);
2312     arm_reloc_property_table = new Arm_reloc_property_table();
2313   }
2314
2315  private:
2316   // The class which scans relocations.
2317   class Scan
2318   {
2319    public:
2320     Scan()
2321       : issued_non_pic_error_(false)
2322     { }
2323
2324     inline void
2325     local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2326           Sized_relobj<32, big_endian>* object,
2327           unsigned int data_shndx,
2328           Output_section* output_section,
2329           const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2330           const elfcpp::Sym<32, big_endian>& lsym);
2331
2332     inline void
2333     global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2334            Sized_relobj<32, big_endian>* object,
2335            unsigned int data_shndx,
2336            Output_section* output_section,
2337            const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2338            Symbol* gsym);
2339
2340     inline bool
2341     local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2342                                         Sized_relobj<32, big_endian>* ,
2343                                         unsigned int ,
2344                                         Output_section* ,
2345                                         const elfcpp::Rel<32, big_endian>& ,
2346                                         unsigned int ,
2347                                         const elfcpp::Sym<32, big_endian>&)
2348     { return false; }
2349
2350     inline bool
2351     global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2352                                          Sized_relobj<32, big_endian>* ,
2353                                          unsigned int ,
2354                                          Output_section* ,
2355                                          const elfcpp::Rel<32, big_endian>& ,
2356                                          unsigned int , Symbol*)
2357     { return false; }
2358
2359    private:
2360     static void
2361     unsupported_reloc_local(Sized_relobj<32, big_endian>*,
2362                             unsigned int r_type);
2363
2364     static void
2365     unsupported_reloc_global(Sized_relobj<32, big_endian>*,
2366                              unsigned int r_type, Symbol*);
2367
2368     void
2369     check_non_pic(Relobj*, unsigned int r_type);
2370
2371     // Almost identical to Symbol::needs_plt_entry except that it also
2372     // handles STT_ARM_TFUNC.
2373     static bool
2374     symbol_needs_plt_entry(const Symbol* sym)
2375     {
2376       // An undefined symbol from an executable does not need a PLT entry.
2377       if (sym->is_undefined() && !parameters->options().shared())
2378         return false;
2379
2380       return (!parameters->doing_static_link()
2381               && (sym->type() == elfcpp::STT_FUNC
2382                   || sym->type() == elfcpp::STT_ARM_TFUNC)
2383               && (sym->is_from_dynobj()
2384                   || sym->is_undefined()
2385                   || sym->is_preemptible()));
2386     }
2387
2388     // Whether we have issued an error about a non-PIC compilation.
2389     bool issued_non_pic_error_;
2390   };
2391
2392   // The class which implements relocation.
2393   class Relocate
2394   {
2395    public:
2396     Relocate()
2397     { }
2398
2399     ~Relocate()
2400     { }
2401
2402     // Return whether the static relocation needs to be applied.
2403     inline bool
2404     should_apply_static_reloc(const Sized_symbol<32>* gsym,
2405                               int ref_flags,
2406                               bool is_32bit,
2407                               Output_section* output_section);
2408
2409     // Do a relocation.  Return false if the caller should not issue
2410     // any warnings about this relocation.
2411     inline bool
2412     relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2413              Output_section*,  size_t relnum,
2414              const elfcpp::Rel<32, big_endian>&,
2415              unsigned int r_type, const Sized_symbol<32>*,
2416              const Symbol_value<32>*,
2417              unsigned char*, Arm_address,
2418              section_size_type);
2419
2420     // Return whether we want to pass flag NON_PIC_REF for this
2421     // reloc.  This means the relocation type accesses a symbol not via
2422     // GOT or PLT.
2423     static inline bool
2424     reloc_is_non_pic (unsigned int r_type)
2425     {
2426       switch (r_type)
2427         {
2428         // These relocation types reference GOT or PLT entries explicitly.
2429         case elfcpp::R_ARM_GOT_BREL:
2430         case elfcpp::R_ARM_GOT_ABS:
2431         case elfcpp::R_ARM_GOT_PREL:
2432         case elfcpp::R_ARM_GOT_BREL12:
2433         case elfcpp::R_ARM_PLT32_ABS:
2434         case elfcpp::R_ARM_TLS_GD32:
2435         case elfcpp::R_ARM_TLS_LDM32:
2436         case elfcpp::R_ARM_TLS_IE32:
2437         case elfcpp::R_ARM_TLS_IE12GP:
2438
2439         // These relocate types may use PLT entries.
2440         case elfcpp::R_ARM_CALL:
2441         case elfcpp::R_ARM_THM_CALL:
2442         case elfcpp::R_ARM_JUMP24:
2443         case elfcpp::R_ARM_THM_JUMP24:
2444         case elfcpp::R_ARM_THM_JUMP19:
2445         case elfcpp::R_ARM_PLT32:
2446         case elfcpp::R_ARM_THM_XPC22:
2447         case elfcpp::R_ARM_PREL31:
2448         case elfcpp::R_ARM_SBREL31:
2449           return false;
2450
2451         default:
2452           return true;
2453         }
2454     }
2455
2456    private:
2457     // Do a TLS relocation.
2458     inline typename Arm_relocate_functions<big_endian>::Status
2459     relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2460                  size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2461                  const Sized_symbol<32>*, const Symbol_value<32>*,
2462                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2463                  section_size_type);
2464
2465   };
2466
2467   // A class which returns the size required for a relocation type,
2468   // used while scanning relocs during a relocatable link.
2469   class Relocatable_size_for_reloc
2470   {
2471    public:
2472     unsigned int
2473     get_size_for_reloc(unsigned int, Relobj*);
2474   };
2475
2476   // Adjust TLS relocation type based on the options and whether this
2477   // is a local symbol.
2478   static tls::Tls_optimization
2479   optimize_tls_reloc(bool is_final, int r_type);
2480
2481   // Get the GOT section, creating it if necessary.
2482   Arm_output_data_got<big_endian>*
2483   got_section(Symbol_table*, Layout*);
2484
2485   // Get the GOT PLT section.
2486   Output_data_space*
2487   got_plt_section() const
2488   {
2489     gold_assert(this->got_plt_ != NULL);
2490     return this->got_plt_;
2491   }
2492
2493   // Create a PLT entry for a global symbol.
2494   void
2495   make_plt_entry(Symbol_table*, Layout*, Symbol*);
2496
2497   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2498   void
2499   define_tls_base_symbol(Symbol_table*, Layout*);
2500
2501   // Create a GOT entry for the TLS module index.
2502   unsigned int
2503   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2504                       Sized_relobj<32, big_endian>* object);
2505
2506   // Get the PLT section.
2507   const Output_data_plt_arm<big_endian>*
2508   plt_section() const
2509   {
2510     gold_assert(this->plt_ != NULL);
2511     return this->plt_;
2512   }
2513
2514   // Get the dynamic reloc section, creating it if necessary.
2515   Reloc_section*
2516   rel_dyn_section(Layout*);
2517
2518   // Get the section to use for TLS_DESC relocations.
2519   Reloc_section*
2520   rel_tls_desc_section(Layout*) const;
2521
2522   // Return true if the symbol may need a COPY relocation.
2523   // References from an executable object to non-function symbols
2524   // defined in a dynamic object may need a COPY relocation.
2525   bool
2526   may_need_copy_reloc(Symbol* gsym)
2527   {
2528     return (gsym->type() != elfcpp::STT_ARM_TFUNC
2529             && gsym->may_need_copy_reloc());
2530   }
2531
2532   // Add a potential copy relocation.
2533   void
2534   copy_reloc(Symbol_table* symtab, Layout* layout,
2535              Sized_relobj<32, big_endian>* object,
2536              unsigned int shndx, Output_section* output_section,
2537              Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2538   {
2539     this->copy_relocs_.copy_reloc(symtab, layout,
2540                                   symtab->get_sized_symbol<32>(sym),
2541                                   object, shndx, output_section, reloc,
2542                                   this->rel_dyn_section(layout));
2543   }
2544
2545   // Whether two EABI versions are compatible.
2546   static bool
2547   are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2548
2549   // Merge processor-specific flags from input object and those in the ELF
2550   // header of the output.
2551   void
2552   merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2553
2554   // Get the secondary compatible architecture.
2555   static int
2556   get_secondary_compatible_arch(const Attributes_section_data*);
2557
2558   // Set the secondary compatible architecture.
2559   static void
2560   set_secondary_compatible_arch(Attributes_section_data*, int);
2561
2562   static int
2563   tag_cpu_arch_combine(const char*, int, int*, int, int);
2564
2565   // Helper to print AEABI enum tag value.
2566   static std::string
2567   aeabi_enum_name(unsigned int);
2568
2569   // Return string value for TAG_CPU_name.
2570   static std::string
2571   tag_cpu_name_value(unsigned int);
2572
2573   // Merge object attributes from input object and those in the output.
2574   void
2575   merge_object_attributes(const char*, const Attributes_section_data*);
2576
2577   // Helper to get an AEABI object attribute
2578   Object_attribute*
2579   get_aeabi_object_attribute(int tag) const
2580   {
2581     Attributes_section_data* pasd = this->attributes_section_data_;
2582     gold_assert(pasd != NULL);
2583     Object_attribute* attr =
2584       pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2585     gold_assert(attr != NULL);
2586     return attr;
2587   }
2588
2589   //
2590   // Methods to support stub-generations.
2591   //
2592
2593   // Group input sections for stub generation.
2594   void
2595   group_sections(Layout*, section_size_type, bool);
2596
2597   // Scan a relocation for stub generation.
2598   void
2599   scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2600                       const Sized_symbol<32>*, unsigned int,
2601                       const Symbol_value<32>*,
2602                       elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2603
2604   // Scan a relocation section for stub.
2605   template<int sh_type>
2606   void
2607   scan_reloc_section_for_stubs(
2608       const Relocate_info<32, big_endian>* relinfo,
2609       const unsigned char* prelocs,
2610       size_t reloc_count,
2611       Output_section* output_section,
2612       bool needs_special_offset_handling,
2613       const unsigned char* view,
2614       elfcpp::Elf_types<32>::Elf_Addr view_address,
2615       section_size_type);
2616
2617   // Fix .ARM.exidx section coverage.
2618   void
2619   fix_exidx_coverage(Layout*, Arm_output_section<big_endian>*, Symbol_table*);
2620
2621   // Functors for STL set.
2622   struct output_section_address_less_than
2623   {
2624     bool
2625     operator()(const Output_section* s1, const Output_section* s2) const
2626     { return s1->address() < s2->address(); }
2627   };
2628
2629   // Information about this specific target which we pass to the
2630   // general Target structure.
2631   static const Target::Target_info arm_info;
2632
2633   // The types of GOT entries needed for this platform.
2634   enum Got_type
2635   {
2636     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
2637     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
2638     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
2639     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
2640     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
2641   };
2642
2643   typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2644
2645   // Map input section to Arm_input_section.
2646   typedef Unordered_map<Section_id,
2647                         Arm_input_section<big_endian>*,
2648                         Section_id_hash>
2649           Arm_input_section_map;
2650     
2651   // Map output addresses to relocs for Cortex-A8 erratum.
2652   typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2653           Cortex_a8_relocs_info;
2654
2655   // The GOT section.
2656   Arm_output_data_got<big_endian>* got_;
2657   // The PLT section.
2658   Output_data_plt_arm<big_endian>* plt_;
2659   // The GOT PLT section.
2660   Output_data_space* got_plt_;
2661   // The dynamic reloc section.
2662   Reloc_section* rel_dyn_;
2663   // Relocs saved to avoid a COPY reloc.
2664   Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2665   // Space for variables copied with a COPY reloc.
2666   Output_data_space* dynbss_;
2667   // Offset of the GOT entry for the TLS module index.
2668   unsigned int got_mod_index_offset_;
2669   // True if the _TLS_MODULE_BASE_ symbol has been defined.
2670   bool tls_base_symbol_defined_;
2671   // Vector of Stub_tables created.
2672   Stub_table_list stub_tables_;
2673   // Stub factory.
2674   const Stub_factory &stub_factory_;
2675   // Whether we can use BLX.
2676   bool may_use_blx_;
2677   // Whether we force PIC branch veneers.
2678   bool should_force_pic_veneer_;
2679   // Map for locating Arm_input_sections.
2680   Arm_input_section_map arm_input_section_map_;
2681   // Attributes section data in output.
2682   Attributes_section_data* attributes_section_data_;
2683   // Whether we want to fix code for Cortex-A8 erratum.
2684   bool fix_cortex_a8_;
2685   // Map addresses to relocs for Cortex-A8 erratum.
2686   Cortex_a8_relocs_info cortex_a8_relocs_info_;
2687 };
2688
2689 template<bool big_endian>
2690 const Target::Target_info Target_arm<big_endian>::arm_info =
2691 {
2692   32,                   // size
2693   big_endian,           // is_big_endian
2694   elfcpp::EM_ARM,       // machine_code
2695   false,                // has_make_symbol
2696   false,                // has_resolve
2697   false,                // has_code_fill
2698   true,                 // is_default_stack_executable
2699   '\0',                 // wrap_char
2700   "/usr/lib/libc.so.1", // dynamic_linker
2701   0x8000,               // default_text_segment_address
2702   0x1000,               // abi_pagesize (overridable by -z max-page-size)
2703   0x1000,               // common_pagesize (overridable by -z common-page-size)
2704   elfcpp::SHN_UNDEF,    // small_common_shndx
2705   elfcpp::SHN_UNDEF,    // large_common_shndx
2706   0,                    // small_common_section_flags
2707   0,                    // large_common_section_flags
2708   ".ARM.attributes",    // attributes_section
2709   "aeabi"               // attributes_vendor
2710 };
2711
2712 // Arm relocate functions class
2713 //
2714
2715 template<bool big_endian>
2716 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2717 {
2718  public:
2719   typedef enum
2720   {
2721     STATUS_OKAY,        // No error during relocation.
2722     STATUS_OVERFLOW,    // Relocation oveflow.
2723     STATUS_BAD_RELOC    // Relocation cannot be applied.
2724   } Status;
2725
2726  private:
2727   typedef Relocate_functions<32, big_endian> Base;
2728   typedef Arm_relocate_functions<big_endian> This;
2729
2730   // Encoding of imm16 argument for movt and movw ARM instructions
2731   // from ARM ARM:
2732   //     
2733   //     imm16 := imm4 | imm12
2734   //
2735   //  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 
2736   // +-------+---------------+-------+-------+-----------------------+
2737   // |       |               |imm4   |       |imm12                  |
2738   // +-------+---------------+-------+-------+-----------------------+
2739
2740   // Extract the relocation addend from VAL based on the ARM
2741   // instruction encoding described above.
2742   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2743   extract_arm_movw_movt_addend(
2744       typename elfcpp::Swap<32, big_endian>::Valtype val)
2745   {
2746     // According to the Elf ABI for ARM Architecture the immediate
2747     // field is sign-extended to form the addend.
2748     return utils::sign_extend<16>(((val >> 4) & 0xf000) | (val & 0xfff));
2749   }
2750
2751   // Insert X into VAL based on the ARM instruction encoding described
2752   // above.
2753   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2754   insert_val_arm_movw_movt(
2755       typename elfcpp::Swap<32, big_endian>::Valtype val,
2756       typename elfcpp::Swap<32, big_endian>::Valtype x)
2757   {
2758     val &= 0xfff0f000;
2759     val |= x & 0x0fff;
2760     val |= (x & 0xf000) << 4;
2761     return val;
2762   }
2763
2764   // Encoding of imm16 argument for movt and movw Thumb2 instructions
2765   // from ARM ARM:
2766   //     
2767   //     imm16 := imm4 | i | imm3 | imm8
2768   //
2769   //  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 
2770   // +---------+-+-----------+-------++-+-----+-------+---------------+
2771   // |         |i|           |imm4   || |imm3 |       |imm8           |
2772   // +---------+-+-----------+-------++-+-----+-------+---------------+
2773
2774   // Extract the relocation addend from VAL based on the Thumb2
2775   // instruction encoding described above.
2776   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2777   extract_thumb_movw_movt_addend(
2778       typename elfcpp::Swap<32, big_endian>::Valtype val)
2779   {
2780     // According to the Elf ABI for ARM Architecture the immediate
2781     // field is sign-extended to form the addend.
2782     return utils::sign_extend<16>(((val >> 4) & 0xf000)
2783                                   | ((val >> 15) & 0x0800)
2784                                   | ((val >> 4) & 0x0700)
2785                                   | (val & 0x00ff));
2786   }
2787
2788   // Insert X into VAL based on the Thumb2 instruction encoding
2789   // described above.
2790   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2791   insert_val_thumb_movw_movt(
2792       typename elfcpp::Swap<32, big_endian>::Valtype val,
2793       typename elfcpp::Swap<32, big_endian>::Valtype x)
2794   {
2795     val &= 0xfbf08f00;
2796     val |= (x & 0xf000) << 4;
2797     val |= (x & 0x0800) << 15;
2798     val |= (x & 0x0700) << 4;
2799     val |= (x & 0x00ff);
2800     return val;
2801   }
2802
2803   // Calculate the smallest constant Kn for the specified residual.
2804   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
2805   static uint32_t
2806   calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
2807   {
2808     int32_t msb;
2809
2810     if (residual == 0)
2811       return 0;
2812     // Determine the most significant bit in the residual and
2813     // align the resulting value to a 2-bit boundary.
2814     for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
2815       ;
2816     // The desired shift is now (msb - 6), or zero, whichever
2817     // is the greater.
2818     return (((msb - 6) < 0) ? 0 : (msb - 6));
2819   }
2820
2821   // Calculate the final residual for the specified group index.
2822   // If the passed group index is less than zero, the method will return
2823   // the value of the specified residual without any change.
2824   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
2825   static typename elfcpp::Swap<32, big_endian>::Valtype
2826   calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
2827                     const int group)
2828   {
2829     for (int n = 0; n <= group; n++)
2830       {
2831         // Calculate which part of the value to mask.
2832         uint32_t shift = calc_grp_kn(residual);
2833         // Calculate the residual for the next time around.
2834         residual &= ~(residual & (0xff << shift));
2835       }
2836
2837     return residual;
2838   }
2839
2840   // Calculate the value of Gn for the specified group index.
2841   // We return it in the form of an encoded constant-and-rotation.
2842   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
2843   static typename elfcpp::Swap<32, big_endian>::Valtype
2844   calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
2845               const int group)
2846   {
2847     typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
2848     uint32_t shift = 0;
2849
2850     for (int n = 0; n <= group; n++)
2851       {
2852         // Calculate which part of the value to mask.
2853         shift = calc_grp_kn(residual);
2854         // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
2855         gn = residual & (0xff << shift);
2856         // Calculate the residual for the next time around.
2857         residual &= ~gn;
2858       }
2859     // Return Gn in the form of an encoded constant-and-rotation.
2860     return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
2861   }
2862
2863  public:
2864   // Handle ARM long branches.
2865   static typename This::Status
2866   arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
2867                     unsigned char *, const Sized_symbol<32>*,
2868                     const Arm_relobj<big_endian>*, unsigned int,
2869                     const Symbol_value<32>*, Arm_address, Arm_address, bool);
2870
2871   // Handle THUMB long branches.
2872   static typename This::Status
2873   thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
2874                       unsigned char *, const Sized_symbol<32>*,
2875                       const Arm_relobj<big_endian>*, unsigned int,
2876                       const Symbol_value<32>*, Arm_address, Arm_address, bool);
2877
2878
2879   // Return the branch offset of a 32-bit THUMB branch.
2880   static inline int32_t
2881   thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
2882   {
2883     // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
2884     // involving the J1 and J2 bits.
2885     uint32_t s = (upper_insn & (1U << 10)) >> 10;
2886     uint32_t upper = upper_insn & 0x3ffU;
2887     uint32_t lower = lower_insn & 0x7ffU;
2888     uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
2889     uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
2890     uint32_t i1 = j1 ^ s ? 0 : 1;
2891     uint32_t i2 = j2 ^ s ? 0 : 1;
2892
2893     return utils::sign_extend<25>((s << 24) | (i1 << 23) | (i2 << 22)
2894                                   | (upper << 12) | (lower << 1));
2895   }
2896
2897   // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
2898   // UPPER_INSN is the original upper instruction of the branch.  Caller is
2899   // responsible for overflow checking and BLX offset adjustment.
2900   static inline uint16_t
2901   thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
2902   {
2903     uint32_t s = offset < 0 ? 1 : 0;
2904     uint32_t bits = static_cast<uint32_t>(offset);
2905     return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
2906   }
2907
2908   // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
2909   // LOWER_INSN is the original lower instruction of the branch.  Caller is
2910   // responsible for overflow checking and BLX offset adjustment.
2911   static inline uint16_t
2912   thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
2913   {
2914     uint32_t s = offset < 0 ? 1 : 0;
2915     uint32_t bits = static_cast<uint32_t>(offset);
2916     return ((lower_insn & ~0x2fffU)
2917             | ((((bits >> 23) & 1) ^ !s) << 13)
2918             | ((((bits >> 22) & 1) ^ !s) << 11)
2919             | ((bits >> 1) & 0x7ffU));
2920   }
2921
2922   // Return the branch offset of a 32-bit THUMB conditional branch.
2923   static inline int32_t
2924   thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
2925   {
2926     uint32_t s = (upper_insn & 0x0400U) >> 10;
2927     uint32_t j1 = (lower_insn & 0x2000U) >> 13;
2928     uint32_t j2 = (lower_insn & 0x0800U) >> 11;
2929     uint32_t lower = (lower_insn & 0x07ffU);
2930     uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
2931
2932     return utils::sign_extend<21>((upper << 12) | (lower << 1));
2933   }
2934
2935   // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
2936   // instruction.  UPPER_INSN is the original upper instruction of the branch.
2937   // Caller is responsible for overflow checking.
2938   static inline uint16_t
2939   thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
2940   {
2941     uint32_t s = offset < 0 ? 1 : 0;
2942     uint32_t bits = static_cast<uint32_t>(offset);
2943     return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
2944   }
2945
2946   // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
2947   // instruction.  LOWER_INSN is the original lower instruction of the branch.
2948   // Caller is reponsible for overflow checking.
2949   static inline uint16_t
2950   thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
2951   {
2952     uint32_t bits = static_cast<uint32_t>(offset);
2953     uint32_t j2 = (bits & 0x00080000U) >> 19;
2954     uint32_t j1 = (bits & 0x00040000U) >> 18;
2955     uint32_t lo = (bits & 0x00000ffeU) >> 1;
2956
2957     return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
2958   }
2959
2960   // R_ARM_ABS8: S + A
2961   static inline typename This::Status
2962   abs8(unsigned char *view,
2963        const Sized_relobj<32, big_endian>* object,
2964        const Symbol_value<32>* psymval)
2965   {
2966     typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
2967     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
2968     Valtype* wv = reinterpret_cast<Valtype*>(view);
2969     Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
2970     Reltype addend = utils::sign_extend<8>(val);
2971     Reltype x = psymval->value(object, addend);
2972     val = utils::bit_select(val, x, 0xffU);
2973     elfcpp::Swap<8, big_endian>::writeval(wv, val);
2974     return (utils::has_signed_unsigned_overflow<8>(x)
2975             ? This::STATUS_OVERFLOW
2976             : This::STATUS_OKAY);
2977   }
2978
2979   // R_ARM_THM_ABS5: S + A
2980   static inline typename This::Status
2981   thm_abs5(unsigned char *view,
2982        const Sized_relobj<32, big_endian>* object,
2983        const Symbol_value<32>* psymval)
2984   {
2985     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
2986     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
2987     Valtype* wv = reinterpret_cast<Valtype*>(view);
2988     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
2989     Reltype addend = (val & 0x7e0U) >> 6;
2990     Reltype x = psymval->value(object, addend);
2991     val = utils::bit_select(val, x << 6, 0x7e0U);
2992     elfcpp::Swap<16, big_endian>::writeval(wv, val);
2993     return (utils::has_overflow<5>(x)
2994             ? This::STATUS_OVERFLOW
2995             : This::STATUS_OKAY);
2996   }
2997
2998   // R_ARM_ABS12: S + A
2999   static inline typename This::Status
3000   abs12(unsigned char *view,
3001         const Sized_relobj<32, big_endian>* object,
3002         const Symbol_value<32>* psymval)
3003   {
3004     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3005     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3006     Valtype* wv = reinterpret_cast<Valtype*>(view);
3007     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3008     Reltype addend = val & 0x0fffU;
3009     Reltype x = psymval->value(object, addend);
3010     val = utils::bit_select(val, x, 0x0fffU);
3011     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3012     return (utils::has_overflow<12>(x)
3013             ? This::STATUS_OVERFLOW
3014             : This::STATUS_OKAY);
3015   }
3016
3017   // R_ARM_ABS16: S + A
3018   static inline typename This::Status
3019   abs16(unsigned char *view,
3020         const Sized_relobj<32, big_endian>* object,
3021         const Symbol_value<32>* psymval)
3022   {
3023     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3024     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3025     Valtype* wv = reinterpret_cast<Valtype*>(view);
3026     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3027     Reltype addend = utils::sign_extend<16>(val);
3028     Reltype x = psymval->value(object, addend);
3029     val = utils::bit_select(val, x, 0xffffU);
3030     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3031     return (utils::has_signed_unsigned_overflow<16>(x)
3032             ? This::STATUS_OVERFLOW
3033             : This::STATUS_OKAY);
3034   }
3035
3036   // R_ARM_ABS32: (S + A) | T
3037   static inline typename This::Status
3038   abs32(unsigned char *view,
3039         const Sized_relobj<32, big_endian>* object,
3040         const Symbol_value<32>* psymval,
3041         Arm_address thumb_bit)
3042   {
3043     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3044     Valtype* wv = reinterpret_cast<Valtype*>(view);
3045     Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
3046     Valtype x = psymval->value(object, addend) | thumb_bit;
3047     elfcpp::Swap<32, big_endian>::writeval(wv, x);
3048     return This::STATUS_OKAY;
3049   }
3050
3051   // R_ARM_REL32: (S + A) | T - P
3052   static inline typename This::Status
3053   rel32(unsigned char *view,
3054         const Sized_relobj<32, big_endian>* object,
3055         const Symbol_value<32>* psymval,
3056         Arm_address address,
3057         Arm_address thumb_bit)
3058   {
3059     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3060     Valtype* wv = reinterpret_cast<Valtype*>(view);
3061     Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
3062     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3063     elfcpp::Swap<32, big_endian>::writeval(wv, x);
3064     return This::STATUS_OKAY;
3065   }
3066
3067   // R_ARM_THM_JUMP24: (S + A) | T - P
3068   static typename This::Status
3069   thm_jump19(unsigned char *view, const Arm_relobj<big_endian>* object,
3070              const Symbol_value<32>* psymval, Arm_address address,
3071              Arm_address thumb_bit);
3072
3073   // R_ARM_THM_JUMP6: S + A – P
3074   static inline typename This::Status
3075   thm_jump6(unsigned char *view,
3076             const Sized_relobj<32, big_endian>* object,
3077             const Symbol_value<32>* psymval,
3078             Arm_address address)
3079   {
3080     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3081     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3082     Valtype* wv = reinterpret_cast<Valtype*>(view);
3083     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3084     // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3085     Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3086     Reltype x = (psymval->value(object, addend) - address);
3087     val = (val & 0xfd07) | ((x  & 0x0040) << 3) | ((val & 0x003e) << 2);
3088     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3089     // CZB does only forward jumps.
3090     return ((x > 0x007e)
3091             ? This::STATUS_OVERFLOW
3092             : This::STATUS_OKAY);
3093   }
3094
3095   // R_ARM_THM_JUMP8: S + A – P
3096   static inline typename This::Status
3097   thm_jump8(unsigned char *view,
3098             const Sized_relobj<32, big_endian>* object,
3099             const Symbol_value<32>* psymval,
3100             Arm_address address)
3101   {
3102     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3103     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3104     Valtype* wv = reinterpret_cast<Valtype*>(view);
3105     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3106     Reltype addend = utils::sign_extend<8>((val & 0x00ff) << 1);
3107     Reltype x = (psymval->value(object, addend) - address);
3108     elfcpp::Swap<16, big_endian>::writeval(wv, (val & 0xff00) | ((x & 0x01fe) >> 1));
3109     return (utils::has_overflow<8>(x)
3110             ? This::STATUS_OVERFLOW
3111             : This::STATUS_OKAY);
3112   }
3113
3114   // R_ARM_THM_JUMP11: S + A – P
3115   static inline typename This::Status
3116   thm_jump11(unsigned char *view,
3117             const Sized_relobj<32, big_endian>* object,
3118             const Symbol_value<32>* psymval,
3119             Arm_address address)
3120   {
3121     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3122     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3123     Valtype* wv = reinterpret_cast<Valtype*>(view);
3124     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3125     Reltype addend = utils::sign_extend<11>((val & 0x07ff) << 1);
3126     Reltype x = (psymval->value(object, addend) - address);
3127     elfcpp::Swap<16, big_endian>::writeval(wv, (val & 0xf800) | ((x & 0x0ffe) >> 1));
3128     return (utils::has_overflow<11>(x)
3129             ? This::STATUS_OVERFLOW
3130             : This::STATUS_OKAY);
3131   }
3132
3133   // R_ARM_BASE_PREL: B(S) + A - P
3134   static inline typename This::Status
3135   base_prel(unsigned char* view,
3136             Arm_address origin,
3137             Arm_address address)
3138   {
3139     Base::rel32(view, origin - address);
3140     return STATUS_OKAY;
3141   }
3142
3143   // R_ARM_BASE_ABS: B(S) + A
3144   static inline typename This::Status
3145   base_abs(unsigned char* view,
3146            Arm_address origin)
3147   {
3148     Base::rel32(view, origin);
3149     return STATUS_OKAY;
3150   }
3151
3152   // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3153   static inline typename This::Status
3154   got_brel(unsigned char* view,
3155            typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3156   {
3157     Base::rel32(view, got_offset);
3158     return This::STATUS_OKAY;
3159   }
3160
3161   // R_ARM_GOT_PREL: GOT(S) + A - P
3162   static inline typename This::Status
3163   got_prel(unsigned char *view,
3164            Arm_address got_entry,
3165            Arm_address address)
3166   {
3167     Base::rel32(view, got_entry - address);
3168     return This::STATUS_OKAY;
3169   }
3170
3171   // R_ARM_PREL: (S + A) | T - P
3172   static inline typename This::Status
3173   prel31(unsigned char *view,
3174          const Sized_relobj<32, big_endian>* object,
3175          const Symbol_value<32>* psymval,
3176          Arm_address address,
3177          Arm_address thumb_bit)
3178   {
3179     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3180     Valtype* wv = reinterpret_cast<Valtype*>(view);
3181     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3182     Valtype addend = utils::sign_extend<31>(val);
3183     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3184     val = utils::bit_select(val, x, 0x7fffffffU);
3185     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3186     return (utils::has_overflow<31>(x) ?
3187             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3188   }
3189
3190   // R_ARM_MOVW_ABS_NC: (S + A) | T     (relative address base is )
3191   // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3192   // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3193   // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3194   static inline typename This::Status
3195   movw(unsigned char* view,
3196        const Sized_relobj<32, big_endian>* object,
3197        const Symbol_value<32>* psymval,
3198        Arm_address relative_address_base,
3199        Arm_address thumb_bit,
3200        bool check_overflow)
3201   {
3202     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3203     Valtype* wv = reinterpret_cast<Valtype*>(view);
3204     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3205     Valtype addend = This::extract_arm_movw_movt_addend(val);
3206     Valtype x = ((psymval->value(object, addend) | thumb_bit)
3207                  - relative_address_base);
3208     val = This::insert_val_arm_movw_movt(val, x);
3209     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3210     return ((check_overflow && utils::has_overflow<16>(x))
3211             ? This::STATUS_OVERFLOW
3212             : This::STATUS_OKAY);
3213   }
3214
3215   // R_ARM_MOVT_ABS: S + A      (relative address base is 0)
3216   // R_ARM_MOVT_PREL: S + A - P
3217   // R_ARM_MOVT_BREL: S + A - B(S)
3218   static inline typename This::Status
3219   movt(unsigned char* view,
3220        const Sized_relobj<32, big_endian>* object,
3221        const Symbol_value<32>* psymval,
3222        Arm_address relative_address_base)
3223   {
3224     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3225     Valtype* wv = reinterpret_cast<Valtype*>(view);
3226     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3227     Valtype addend = This::extract_arm_movw_movt_addend(val);
3228     Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3229     val = This::insert_val_arm_movw_movt(val, x);
3230     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3231     // FIXME: IHI0044D says that we should check for overflow.
3232     return This::STATUS_OKAY;
3233   }
3234
3235   // R_ARM_THM_MOVW_ABS_NC: S + A | T           (relative_address_base is 0)
3236   // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3237   // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3238   // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3239   static inline typename This::Status
3240   thm_movw(unsigned char *view,
3241            const Sized_relobj<32, big_endian>* object,
3242            const Symbol_value<32>* psymval,
3243            Arm_address relative_address_base,
3244            Arm_address thumb_bit,
3245            bool check_overflow)
3246   {
3247     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3248     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3249     Valtype* wv = reinterpret_cast<Valtype*>(view);
3250     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3251                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3252     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3253     Reltype x =
3254       (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3255     val = This::insert_val_thumb_movw_movt(val, x);
3256     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3257     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3258     return ((check_overflow && utils::has_overflow<16>(x))
3259             ? This::STATUS_OVERFLOW
3260             : This::STATUS_OKAY);
3261   }
3262
3263   // R_ARM_THM_MOVT_ABS: S + A          (relative address base is 0)
3264   // R_ARM_THM_MOVT_PREL: S + A - P
3265   // R_ARM_THM_MOVT_BREL: S + A - B(S)
3266   static inline typename This::Status
3267   thm_movt(unsigned char* view,
3268            const Sized_relobj<32, big_endian>* object,
3269            const Symbol_value<32>* psymval,
3270            Arm_address relative_address_base)
3271   {
3272     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3273     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3274     Valtype* wv = reinterpret_cast<Valtype*>(view);
3275     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3276                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3277     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3278     Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3279     val = This::insert_val_thumb_movw_movt(val, x);
3280     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3281     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3282     return This::STATUS_OKAY;
3283   }
3284
3285   // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3286   static inline typename This::Status
3287   thm_alu11(unsigned char* view,
3288             const Sized_relobj<32, big_endian>* object,
3289             const Symbol_value<32>* psymval,
3290             Arm_address address,
3291             Arm_address thumb_bit)
3292   {
3293     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3294     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3295     Valtype* wv = reinterpret_cast<Valtype*>(view);
3296     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3297                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3298
3299     //        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
3300     // -----------------------------------------------------------------------
3301     // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd     |imm8
3302     // ADDW   1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd     |imm8
3303     // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd     |imm8
3304     // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd     |imm8
3305     // SUBW   1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd     |imm8
3306     // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd     |imm8
3307
3308     // Determine a sign for the addend.
3309     const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3310                       || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3311     // Thumb2 addend encoding:
3312     // imm12 := i | imm3 | imm8
3313     int32_t addend = (insn & 0xff)
3314                      | ((insn & 0x00007000) >> 4)
3315                      | ((insn & 0x04000000) >> 15);
3316     // Apply a sign to the added.
3317     addend *= sign;
3318
3319     int32_t x = (psymval->value(object, addend) | thumb_bit)
3320                 - (address & 0xfffffffc);
3321     Reltype val = abs(x);
3322     // Mask out the value and a distinct part of the ADD/SUB opcode
3323     // (bits 7:5 of opword).
3324     insn = (insn & 0xfb0f8f00)
3325            | (val & 0xff)
3326            | ((val & 0x700) << 4)
3327            | ((val & 0x800) << 15);
3328     // Set the opcode according to whether the value to go in the
3329     // place is negative.
3330     if (x < 0)
3331       insn |= 0x00a00000;
3332
3333     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3334     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3335     return ((val > 0xfff) ?
3336             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3337   }
3338
3339   // R_ARM_THM_PC8: S + A - Pa (Thumb)
3340   static inline typename This::Status
3341   thm_pc8(unsigned char* view,
3342           const Sized_relobj<32, big_endian>* object,
3343           const Symbol_value<32>* psymval,
3344           Arm_address address)
3345   {
3346     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3347     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3348     Valtype* wv = reinterpret_cast<Valtype*>(view);
3349     Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3350     Reltype addend = ((insn & 0x00ff) << 2);
3351     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3352     Reltype val = abs(x);
3353     insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3354
3355     elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3356     return ((val > 0x03fc)
3357             ? This::STATUS_OVERFLOW
3358             : This::STATUS_OKAY);
3359   }
3360
3361   // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3362   static inline typename This::Status
3363   thm_pc12(unsigned char* view,
3364            const Sized_relobj<32, big_endian>* object,
3365            const Symbol_value<32>* psymval,
3366            Arm_address address)
3367   {
3368     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3369     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3370     Valtype* wv = reinterpret_cast<Valtype*>(view);
3371     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3372                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3373     // Determine a sign for the addend (positive if the U bit is 1).
3374     const int sign = (insn & 0x00800000) ? 1 : -1;
3375     int32_t addend = (insn & 0xfff);
3376     // Apply a sign to the added.
3377     addend *= sign;
3378
3379     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3380     Reltype val = abs(x);
3381     // Mask out and apply the value and the U bit.
3382     insn = (insn & 0xff7ff000) | (val & 0xfff);
3383     // Set the U bit according to whether the value to go in the
3384     // place is positive.
3385     if (x >= 0)
3386       insn |= 0x00800000;
3387
3388     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3389     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3390     return ((val > 0xfff) ?
3391             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3392   }
3393
3394   // R_ARM_V4BX
3395   static inline typename This::Status
3396   v4bx(const Relocate_info<32, big_endian>* relinfo,
3397        unsigned char *view,
3398        const Arm_relobj<big_endian>* object,
3399        const Arm_address address,
3400        const bool is_interworking)
3401   {
3402
3403     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3404     Valtype* wv = reinterpret_cast<Valtype*>(view);
3405     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3406
3407     // Ensure that we have a BX instruction.
3408     gold_assert((val & 0x0ffffff0) == 0x012fff10);
3409     const uint32_t reg = (val & 0xf);
3410     if (is_interworking && reg != 0xf)
3411       {
3412         Stub_table<big_endian>* stub_table =
3413             object->stub_table(relinfo->data_shndx);
3414         gold_assert(stub_table != NULL);
3415
3416         Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3417         gold_assert(stub != NULL);
3418
3419         int32_t veneer_address =
3420             stub_table->address() + stub->offset() - 8 - address;
3421         gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3422                     && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3423         // Replace with a branch to veneer (B <addr>)
3424         val = (val & 0xf0000000) | 0x0a000000
3425               | ((veneer_address >> 2) & 0x00ffffff);
3426       }
3427     else
3428       {
3429         // Preserve Rm (lowest four bits) and the condition code
3430         // (highest four bits). Other bits encode MOV PC,Rm.
3431         val = (val & 0xf000000f) | 0x01a0f000;
3432       }
3433     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3434     return This::STATUS_OKAY;
3435   }
3436
3437   // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3438   // R_ARM_ALU_PC_G0:    ((S + A) | T) - P
3439   // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3440   // R_ARM_ALU_PC_G1:    ((S + A) | T) - P
3441   // R_ARM_ALU_PC_G2:    ((S + A) | T) - P
3442   // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3443   // R_ARM_ALU_SB_G0:    ((S + A) | T) - B(S)
3444   // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3445   // R_ARM_ALU_SB_G1:    ((S + A) | T) - B(S)
3446   // R_ARM_ALU_SB_G2:    ((S + A) | T) - B(S)
3447   static inline typename This::Status
3448   arm_grp_alu(unsigned char* view,
3449         const Sized_relobj<32, big_endian>* object,
3450         const Symbol_value<32>* psymval,
3451         const int group,
3452         Arm_address address,
3453         Arm_address thumb_bit,
3454         bool check_overflow)
3455   {
3456     gold_assert(group >= 0 && group < 3);
3457     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3458     Valtype* wv = reinterpret_cast<Valtype*>(view);
3459     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3460
3461     // ALU group relocations are allowed only for the ADD/SUB instructions.
3462     // (0x00800000 - ADD, 0x00400000 - SUB)
3463     const Valtype opcode = insn & 0x01e00000;
3464     if (opcode != 0x00800000 && opcode != 0x00400000)
3465       return This::STATUS_BAD_RELOC;
3466
3467     // Determine a sign for the addend.
3468     const int sign = (opcode == 0x00800000) ? 1 : -1;
3469     // shifter = rotate_imm * 2
3470     const uint32_t shifter = (insn & 0xf00) >> 7;
3471     // Initial addend value.
3472     int32_t addend = insn & 0xff;
3473     // Rotate addend right by shifter.
3474     addend = (addend >> shifter) | (addend << (32 - shifter));
3475     // Apply a sign to the added.
3476     addend *= sign;
3477
3478     int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3479     Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3480     // Check for overflow if required
3481     if (check_overflow
3482         && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3483       return This::STATUS_OVERFLOW;
3484
3485     // Mask out the value and the ADD/SUB part of the opcode; take care
3486     // not to destroy the S bit.
3487     insn &= 0xff1ff000;
3488     // Set the opcode according to whether the value to go in the
3489     // place is negative.
3490     insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3491     // Encode the offset (encoded Gn).
3492     insn |= gn;
3493
3494     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3495     return This::STATUS_OKAY;
3496   }
3497
3498   // R_ARM_LDR_PC_G0: S + A - P
3499   // R_ARM_LDR_PC_G1: S + A - P
3500   // R_ARM_LDR_PC_G2: S + A - P
3501   // R_ARM_LDR_SB_G0: S + A - B(S)
3502   // R_ARM_LDR_SB_G1: S + A - B(S)
3503   // R_ARM_LDR_SB_G2: S + A - B(S)
3504   static inline typename This::Status
3505   arm_grp_ldr(unsigned char* view,
3506         const Sized_relobj<32, big_endian>* object,
3507         const Symbol_value<32>* psymval,
3508         const int group,
3509         Arm_address address)
3510   {
3511     gold_assert(group >= 0 && group < 3);
3512     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3513     Valtype* wv = reinterpret_cast<Valtype*>(view);
3514     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3515
3516     const int sign = (insn & 0x00800000) ? 1 : -1;
3517     int32_t addend = (insn & 0xfff) * sign;
3518     int32_t x = (psymval->value(object, addend) - address);
3519     // Calculate the relevant G(n-1) value to obtain this stage residual.
3520     Valtype residual =
3521         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3522     if (residual >= 0x1000)
3523       return This::STATUS_OVERFLOW;
3524
3525     // Mask out the value and U bit.
3526     insn &= 0xff7ff000;
3527     // Set the U bit for non-negative values.
3528     if (x >= 0)
3529       insn |= 0x00800000;
3530     insn |= residual;
3531
3532     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3533     return This::STATUS_OKAY;
3534   }
3535
3536   // R_ARM_LDRS_PC_G0: S + A - P
3537   // R_ARM_LDRS_PC_G1: S + A - P
3538   // R_ARM_LDRS_PC_G2: S + A - P
3539   // R_ARM_LDRS_SB_G0: S + A - B(S)
3540   // R_ARM_LDRS_SB_G1: S + A - B(S)
3541   // R_ARM_LDRS_SB_G2: S + A - B(S)
3542   static inline typename This::Status
3543   arm_grp_ldrs(unsigned char* view,
3544         const Sized_relobj<32, big_endian>* object,
3545         const Symbol_value<32>* psymval,
3546         const int group,
3547         Arm_address address)
3548   {
3549     gold_assert(group >= 0 && group < 3);
3550     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3551     Valtype* wv = reinterpret_cast<Valtype*>(view);
3552     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3553
3554     const int sign = (insn & 0x00800000) ? 1 : -1;
3555     int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3556     int32_t x = (psymval->value(object, addend) - address);
3557     // Calculate the relevant G(n-1) value to obtain this stage residual.
3558     Valtype residual =
3559         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3560    if (residual >= 0x100)
3561       return This::STATUS_OVERFLOW;
3562
3563     // Mask out the value and U bit.
3564     insn &= 0xff7ff0f0;
3565     // Set the U bit for non-negative values.
3566     if (x >= 0)
3567       insn |= 0x00800000;
3568     insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3569
3570     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3571     return This::STATUS_OKAY;
3572   }
3573
3574   // R_ARM_LDC_PC_G0: S + A - P
3575   // R_ARM_LDC_PC_G1: S + A - P
3576   // R_ARM_LDC_PC_G2: S + A - P
3577   // R_ARM_LDC_SB_G0: S + A - B(S)
3578   // R_ARM_LDC_SB_G1: S + A - B(S)
3579   // R_ARM_LDC_SB_G2: S + A - B(S)
3580   static inline typename This::Status
3581   arm_grp_ldc(unsigned char* view,
3582       const Sized_relobj<32, big_endian>* object,
3583       const Symbol_value<32>* psymval,
3584       const int group,
3585       Arm_address address)
3586   {
3587     gold_assert(group >= 0 && group < 3);
3588     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3589     Valtype* wv = reinterpret_cast<Valtype*>(view);
3590     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3591
3592     const int sign = (insn & 0x00800000) ? 1 : -1;
3593     int32_t addend = ((insn & 0xff) << 2) * sign;
3594     int32_t x = (psymval->value(object, addend) - address);
3595     // Calculate the relevant G(n-1) value to obtain this stage residual.
3596     Valtype residual =
3597       Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3598     if ((residual & 0x3) != 0 || residual >= 0x400)
3599       return This::STATUS_OVERFLOW;
3600
3601     // Mask out the value and U bit.
3602     insn &= 0xff7fff00;
3603     // Set the U bit for non-negative values.
3604     if (x >= 0)
3605       insn |= 0x00800000;
3606     insn |= (residual >> 2);
3607
3608     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3609     return This::STATUS_OKAY;
3610   }
3611 };
3612
3613 // Relocate ARM long branches.  This handles relocation types
3614 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3615 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3616 // undefined and we do not use PLT in this relocation.  In such a case,
3617 // the branch is converted into an NOP.
3618
3619 template<bool big_endian>
3620 typename Arm_relocate_functions<big_endian>::Status
3621 Arm_relocate_functions<big_endian>::arm_branch_common(
3622     unsigned int r_type,
3623     const Relocate_info<32, big_endian>* relinfo,
3624     unsigned char *view,
3625     const Sized_symbol<32>* gsym,
3626     const Arm_relobj<big_endian>* object,
3627     unsigned int r_sym,
3628     const Symbol_value<32>* psymval,
3629     Arm_address address,
3630     Arm_address thumb_bit,
3631     bool is_weakly_undefined_without_plt)
3632 {
3633   typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3634   Valtype* wv = reinterpret_cast<Valtype*>(view);
3635   Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3636      
3637   bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3638                     && ((val & 0x0f000000UL) == 0x0a000000UL);
3639   bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3640   bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3641                           && ((val & 0x0f000000UL) == 0x0b000000UL);
3642   bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3643   bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3644
3645   // Check that the instruction is valid.
3646   if (r_type == elfcpp::R_ARM_CALL)
3647     {
3648       if (!insn_is_uncond_bl && !insn_is_blx)
3649         return This::STATUS_BAD_RELOC;
3650     }
3651   else if (r_type == elfcpp::R_ARM_JUMP24)
3652     {
3653       if (!insn_is_b && !insn_is_cond_bl)
3654         return This::STATUS_BAD_RELOC;
3655     }
3656   else if (r_type == elfcpp::R_ARM_PLT32)
3657     {
3658       if (!insn_is_any_branch)
3659         return This::STATUS_BAD_RELOC;
3660     }
3661   else if (r_type == elfcpp::R_ARM_XPC25)
3662     {
3663       // FIXME: AAELF document IH0044C does not say much about it other
3664       // than it being obsolete.
3665       if (!insn_is_any_branch)
3666         return This::STATUS_BAD_RELOC;
3667     }
3668   else
3669     gold_unreachable();
3670
3671   // A branch to an undefined weak symbol is turned into a jump to
3672   // the next instruction unless a PLT entry will be created.
3673   // Do the same for local undefined symbols.
3674   // The jump to the next instruction is optimized as a NOP depending
3675   // on the architecture.
3676   const Target_arm<big_endian>* arm_target =
3677     Target_arm<big_endian>::default_target();
3678   if (is_weakly_undefined_without_plt)
3679     {
3680       Valtype cond = val & 0xf0000000U;
3681       if (arm_target->may_use_arm_nop())
3682         val = cond | 0x0320f000;
3683       else
3684         val = cond | 0x01a00000;        // Using pre-UAL nop: mov r0, r0.
3685       elfcpp::Swap<32, big_endian>::writeval(wv, val);
3686       return This::STATUS_OKAY;
3687     }
3688  
3689   Valtype addend = utils::sign_extend<26>(val << 2);
3690   Valtype branch_target = psymval->value(object, addend);
3691   int32_t branch_offset = branch_target - address;
3692
3693   // We need a stub if the branch offset is too large or if we need
3694   // to switch mode.
3695   bool may_use_blx = arm_target->may_use_blx();
3696   Reloc_stub* stub = NULL;
3697   if (utils::has_overflow<26>(branch_offset)
3698       || ((thumb_bit != 0) && !(may_use_blx && r_type == elfcpp::R_ARM_CALL)))
3699     {
3700       Valtype unadjusted_branch_target = psymval->value(object, 0);
3701
3702       Stub_type stub_type =
3703         Reloc_stub::stub_type_for_reloc(r_type, address,
3704                                         unadjusted_branch_target,
3705                                         (thumb_bit != 0));
3706       if (stub_type != arm_stub_none)
3707         {
3708           Stub_table<big_endian>* stub_table =
3709             object->stub_table(relinfo->data_shndx);
3710           gold_assert(stub_table != NULL);
3711
3712           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3713           stub = stub_table->find_reloc_stub(stub_key);
3714           gold_assert(stub != NULL);
3715           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3716           branch_target = stub_table->address() + stub->offset() + addend;
3717           branch_offset = branch_target - address;
3718           gold_assert(!utils::has_overflow<26>(branch_offset));
3719         }
3720     }
3721
3722   // At this point, if we still need to switch mode, the instruction
3723   // must either be a BLX or a BL that can be converted to a BLX.
3724   if (thumb_bit != 0)
3725     {
3726       // Turn BL to BLX.
3727       gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3728       val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3729     }
3730
3731   val = utils::bit_select(val, (branch_offset >> 2), 0xffffffUL);
3732   elfcpp::Swap<32, big_endian>::writeval(wv, val);
3733   return (utils::has_overflow<26>(branch_offset)
3734           ? This::STATUS_OVERFLOW : This::STATUS_OKAY);
3735 }
3736
3737 // Relocate THUMB long branches.  This handles relocation types
3738 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3739 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3740 // undefined and we do not use PLT in this relocation.  In such a case,
3741 // the branch is converted into an NOP.
3742
3743 template<bool big_endian>
3744 typename Arm_relocate_functions<big_endian>::Status
3745 Arm_relocate_functions<big_endian>::thumb_branch_common(
3746     unsigned int r_type,
3747     const Relocate_info<32, big_endian>* relinfo,
3748     unsigned char *view,
3749     const Sized_symbol<32>* gsym,
3750     const Arm_relobj<big_endian>* object,
3751     unsigned int r_sym,
3752     const Symbol_value<32>* psymval,
3753     Arm_address address,
3754     Arm_address thumb_bit,
3755     bool is_weakly_undefined_without_plt)
3756 {
3757   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3758   Valtype* wv = reinterpret_cast<Valtype*>(view);
3759   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
3760   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
3761
3762   // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
3763   // into account.
3764   bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
3765   bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
3766      
3767   // Check that the instruction is valid.
3768   if (r_type == elfcpp::R_ARM_THM_CALL)
3769     {
3770       if (!is_bl_insn && !is_blx_insn)
3771         return This::STATUS_BAD_RELOC;
3772     }
3773   else if (r_type == elfcpp::R_ARM_THM_JUMP24)
3774     {
3775       // This cannot be a BLX.
3776       if (!is_bl_insn)
3777         return This::STATUS_BAD_RELOC;
3778     }
3779   else if (r_type == elfcpp::R_ARM_THM_XPC22)
3780     {
3781       // Check for Thumb to Thumb call.
3782       if (!is_blx_insn)
3783         return This::STATUS_BAD_RELOC;
3784       if (thumb_bit != 0)
3785         {
3786           gold_warning(_("%s: Thumb BLX instruction targets "
3787                          "thumb function '%s'."),
3788                          object->name().c_str(),
3789                          (gsym ? gsym->name() : "(local)")); 
3790           // Convert BLX to BL.
3791           lower_insn |= 0x1000U;
3792         }
3793     }
3794   else
3795     gold_unreachable();
3796
3797   // A branch to an undefined weak symbol is turned into a jump to
3798   // the next instruction unless a PLT entry will be created.
3799   // The jump to the next instruction is optimized as a NOP.W for
3800   // Thumb-2 enabled architectures.
3801   const Target_arm<big_endian>* arm_target =
3802     Target_arm<big_endian>::default_target();
3803   if (is_weakly_undefined_without_plt)
3804     {
3805       if (arm_target->may_use_thumb2_nop())
3806         {
3807           elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
3808           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
3809         }
3810       else
3811         {
3812           elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
3813           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
3814         }
3815       return This::STATUS_OKAY;
3816     }
3817  
3818   int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
3819   Arm_address branch_target = psymval->value(object, addend);
3820   int32_t branch_offset = branch_target - address;
3821
3822   // We need a stub if the branch offset is too large or if we need
3823   // to switch mode.
3824   bool may_use_blx = arm_target->may_use_blx();
3825   bool thumb2 = arm_target->using_thumb2();
3826   if ((!thumb2 && utils::has_overflow<23>(branch_offset))
3827       || (thumb2 && utils::has_overflow<25>(branch_offset))
3828       || ((thumb_bit == 0)
3829           && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
3830               || r_type == elfcpp::R_ARM_THM_JUMP24)))
3831     {
3832       Arm_address unadjusted_branch_target = psymval->value(object, 0);
3833
3834       Stub_type stub_type =
3835         Reloc_stub::stub_type_for_reloc(r_type, address,
3836                                         unadjusted_branch_target,
3837                                         (thumb_bit != 0));
3838
3839       if (stub_type != arm_stub_none)
3840         {
3841           Stub_table<big_endian>* stub_table =
3842             object->stub_table(relinfo->data_shndx);
3843           gold_assert(stub_table != NULL);
3844
3845           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3846           Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
3847           gold_assert(stub != NULL);
3848           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3849           branch_target = stub_table->address() + stub->offset() + addend;
3850           branch_offset = branch_target - address;
3851         }
3852     }
3853
3854   // At this point, if we still need to switch mode, the instruction
3855   // must either be a BLX or a BL that can be converted to a BLX.
3856   if (thumb_bit == 0)
3857     {
3858       gold_assert(may_use_blx
3859                   && (r_type == elfcpp::R_ARM_THM_CALL
3860                       || r_type == elfcpp::R_ARM_THM_XPC22));
3861       // Make sure this is a BLX.
3862       lower_insn &= ~0x1000U;
3863     }
3864   else
3865     {
3866       // Make sure this is a BL.
3867       lower_insn |= 0x1000U;
3868     }
3869
3870   if ((lower_insn & 0x5000U) == 0x4000U)
3871     // For a BLX instruction, make sure that the relocation is rounded up
3872     // to a word boundary.  This follows the semantics of the instruction
3873     // which specifies that bit 1 of the target address will come from bit
3874     // 1 of the base address.
3875     branch_offset = (branch_offset + 2) & ~3;
3876
3877   // Put BRANCH_OFFSET back into the insn.  Assumes two's complement.
3878   // We use the Thumb-2 encoding, which is safe even if dealing with
3879   // a Thumb-1 instruction by virtue of our overflow check above.  */
3880   upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
3881   lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
3882
3883   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
3884   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
3885
3886   return ((thumb2
3887            ? utils::has_overflow<25>(branch_offset)
3888            : utils::has_overflow<23>(branch_offset))
3889           ? This::STATUS_OVERFLOW
3890           : This::STATUS_OKAY);
3891 }
3892
3893 // Relocate THUMB-2 long conditional branches.
3894 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3895 // undefined and we do not use PLT in this relocation.  In such a case,
3896 // the branch is converted into an NOP.
3897
3898 template<bool big_endian>
3899 typename Arm_relocate_functions<big_endian>::Status
3900 Arm_relocate_functions<big_endian>::thm_jump19(
3901     unsigned char *view,
3902     const Arm_relobj<big_endian>* object,
3903     const Symbol_value<32>* psymval,
3904     Arm_address address,
3905     Arm_address thumb_bit)
3906 {
3907   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3908   Valtype* wv = reinterpret_cast<Valtype*>(view);
3909   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
3910   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
3911   int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
3912
3913   Arm_address branch_target = psymval->value(object, addend);
3914   int32_t branch_offset = branch_target - address;
3915
3916   // ??? Should handle interworking?  GCC might someday try to
3917   // use this for tail calls.
3918   // FIXME: We do support thumb entry to PLT yet.
3919   if (thumb_bit == 0)
3920     {
3921       gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
3922       return This::STATUS_BAD_RELOC;
3923     }
3924
3925   // Put RELOCATION back into the insn.
3926   upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
3927   lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
3928
3929   // Put the relocated value back in the object file:
3930   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
3931   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
3932
3933   return (utils::has_overflow<21>(branch_offset)
3934           ? This::STATUS_OVERFLOW
3935           : This::STATUS_OKAY);
3936 }
3937
3938 // Get the GOT section, creating it if necessary.
3939
3940 template<bool big_endian>
3941 Arm_output_data_got<big_endian>*
3942 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
3943 {
3944   if (this->got_ == NULL)
3945     {
3946       gold_assert(symtab != NULL && layout != NULL);
3947
3948       this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
3949
3950       Output_section* os;
3951       os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
3952                                            (elfcpp::SHF_ALLOC
3953                                             | elfcpp::SHF_WRITE),
3954                                            this->got_, false, false, false,
3955                                            true);
3956       // The old GNU linker creates a .got.plt section.  We just
3957       // create another set of data in the .got section.  Note that we
3958       // always create a PLT if we create a GOT, although the PLT
3959       // might be empty.
3960       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
3961       os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
3962                                            (elfcpp::SHF_ALLOC
3963                                             | elfcpp::SHF_WRITE),
3964                                            this->got_plt_, false, false,
3965                                            false, false);
3966
3967       // The first three entries are reserved.
3968       this->got_plt_->set_current_data_size(3 * 4);
3969
3970       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
3971       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
3972                                     Symbol_table::PREDEFINED,
3973                                     this->got_plt_,
3974                                     0, 0, elfcpp::STT_OBJECT,
3975                                     elfcpp::STB_LOCAL,
3976                                     elfcpp::STV_HIDDEN, 0,
3977                                     false, false);
3978     }
3979   return this->got_;
3980 }
3981
3982 // Get the dynamic reloc section, creating it if necessary.
3983
3984 template<bool big_endian>
3985 typename Target_arm<big_endian>::Reloc_section*
3986 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
3987 {
3988   if (this->rel_dyn_ == NULL)
3989     {
3990       gold_assert(layout != NULL);
3991       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
3992       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
3993                                       elfcpp::SHF_ALLOC, this->rel_dyn_, true,
3994                                       false, false, false);
3995     }
3996   return this->rel_dyn_;
3997 }
3998
3999 // Insn_template methods.
4000
4001 // Return byte size of an instruction template.
4002
4003 size_t
4004 Insn_template::size() const
4005 {
4006   switch (this->type())
4007     {
4008     case THUMB16_TYPE:
4009     case THUMB16_SPECIAL_TYPE:
4010       return 2;
4011     case ARM_TYPE:
4012     case THUMB32_TYPE:
4013     case DATA_TYPE:
4014       return 4;
4015     default:
4016       gold_unreachable();
4017     }
4018 }
4019
4020 // Return alignment of an instruction template.
4021
4022 unsigned
4023 Insn_template::alignment() const
4024 {
4025   switch (this->type())
4026     {
4027     case THUMB16_TYPE:
4028     case THUMB16_SPECIAL_TYPE:
4029     case THUMB32_TYPE:
4030       return 2;
4031     case ARM_TYPE:
4032     case DATA_TYPE:
4033       return 4;
4034     default:
4035       gold_unreachable();
4036     }
4037 }
4038
4039 // Stub_template methods.
4040
4041 Stub_template::Stub_template(
4042     Stub_type type, const Insn_template* insns,
4043      size_t insn_count)
4044   : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4045     entry_in_thumb_mode_(false), relocs_()
4046 {
4047   off_t offset = 0;
4048
4049   // Compute byte size and alignment of stub template.
4050   for (size_t i = 0; i < insn_count; i++)
4051     {
4052       unsigned insn_alignment = insns[i].alignment();
4053       size_t insn_size = insns[i].size();
4054       gold_assert((offset & (insn_alignment - 1)) == 0);
4055       this->alignment_ = std::max(this->alignment_, insn_alignment);
4056       switch (insns[i].type())
4057         {
4058         case Insn_template::THUMB16_TYPE:
4059         case Insn_template::THUMB16_SPECIAL_TYPE:
4060           if (i == 0)
4061             this->entry_in_thumb_mode_ = true;
4062           break;
4063
4064         case Insn_template::THUMB32_TYPE:
4065           if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4066             this->relocs_.push_back(Reloc(i, offset));
4067           if (i == 0)
4068             this->entry_in_thumb_mode_ = true;
4069           break;
4070
4071         case Insn_template::ARM_TYPE:
4072           // Handle cases where the target is encoded within the
4073           // instruction.
4074           if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4075             this->relocs_.push_back(Reloc(i, offset));
4076           break;
4077
4078         case Insn_template::DATA_TYPE:
4079           // Entry point cannot be data.
4080           gold_assert(i != 0);
4081           this->relocs_.push_back(Reloc(i, offset));
4082           break;
4083
4084         default:
4085           gold_unreachable();
4086         }
4087       offset += insn_size; 
4088     }
4089   this->size_ = offset;
4090 }
4091
4092 // Stub methods.
4093
4094 // Template to implement do_write for a specific target endianity.
4095
4096 template<bool big_endian>
4097 void inline
4098 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4099 {
4100   const Stub_template* stub_template = this->stub_template();
4101   const Insn_template* insns = stub_template->insns();
4102
4103   // FIXME:  We do not handle BE8 encoding yet.
4104   unsigned char* pov = view;
4105   for (size_t i = 0; i < stub_template->insn_count(); i++)
4106     {
4107       switch (insns[i].type())
4108         {
4109         case Insn_template::THUMB16_TYPE:
4110           elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4111           break;
4112         case Insn_template::THUMB16_SPECIAL_TYPE:
4113           elfcpp::Swap<16, big_endian>::writeval(
4114               pov,
4115               this->thumb16_special(i));
4116           break;
4117         case Insn_template::THUMB32_TYPE:
4118           {
4119             uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4120             uint32_t lo = insns[i].data() & 0xffff;
4121             elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4122             elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4123           }
4124           break;
4125         case Insn_template::ARM_TYPE:
4126         case Insn_template::DATA_TYPE:
4127           elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4128           break;
4129         default:
4130           gold_unreachable();
4131         }
4132       pov += insns[i].size();
4133     }
4134   gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4135
4136
4137 // Reloc_stub::Key methods.
4138
4139 // Dump a Key as a string for debugging.
4140
4141 std::string
4142 Reloc_stub::Key::name() const
4143 {
4144   if (this->r_sym_ == invalid_index)
4145     {
4146       // Global symbol key name
4147       // <stub-type>:<symbol name>:<addend>.
4148       const std::string sym_name = this->u_.symbol->name();
4149       // We need to print two hex number and two colons.  So just add 100 bytes
4150       // to the symbol name size.
4151       size_t len = sym_name.size() + 100;
4152       char* buffer = new char[len];
4153       int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4154                        sym_name.c_str(), this->addend_);
4155       gold_assert(c > 0 && c < static_cast<int>(len));
4156       delete[] buffer;
4157       return std::string(buffer);
4158     }
4159   else
4160     {
4161       // local symbol key name
4162       // <stub-type>:<object>:<r_sym>:<addend>.
4163       const size_t len = 200;
4164       char buffer[len];
4165       int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4166                        this->u_.relobj, this->r_sym_, this->addend_);
4167       gold_assert(c > 0 && c < static_cast<int>(len));
4168       return std::string(buffer);
4169     }
4170 }
4171
4172 // Reloc_stub methods.
4173
4174 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4175 // LOCATION to DESTINATION.
4176 // This code is based on the arm_type_of_stub function in
4177 // bfd/elf32-arm.c.  We have changed the interface a liitle to keep the Stub
4178 // class simple.
4179
4180 Stub_type
4181 Reloc_stub::stub_type_for_reloc(
4182    unsigned int r_type,
4183    Arm_address location,
4184    Arm_address destination,
4185    bool target_is_thumb)
4186 {
4187   Stub_type stub_type = arm_stub_none;
4188
4189   // This is a bit ugly but we want to avoid using a templated class for
4190   // big and little endianities.
4191   bool may_use_blx;
4192   bool should_force_pic_veneer;
4193   bool thumb2;
4194   bool thumb_only;
4195   if (parameters->target().is_big_endian())
4196     {
4197       const Target_arm<true>* big_endian_target =
4198         Target_arm<true>::default_target();
4199       may_use_blx = big_endian_target->may_use_blx();
4200       should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4201       thumb2 = big_endian_target->using_thumb2();
4202       thumb_only = big_endian_target->using_thumb_only();
4203     }
4204   else
4205     {
4206       const Target_arm<false>* little_endian_target =
4207         Target_arm<false>::default_target();
4208       may_use_blx = little_endian_target->may_use_blx();
4209       should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4210       thumb2 = little_endian_target->using_thumb2();
4211       thumb_only = little_endian_target->using_thumb_only();
4212     }
4213
4214   int64_t branch_offset = (int64_t)destination - location;
4215
4216   if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4217     {
4218       // Handle cases where:
4219       // - this call goes too far (different Thumb/Thumb2 max
4220       //   distance)
4221       // - it's a Thumb->Arm call and blx is not available, or it's a
4222       //   Thumb->Arm branch (not bl). A stub is needed in this case.
4223       if ((!thumb2
4224             && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4225                 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4226           || (thumb2
4227               && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4228                   || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4229           || ((!target_is_thumb)
4230               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4231                   || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4232         {
4233           if (target_is_thumb)
4234             {
4235               // Thumb to thumb.
4236               if (!thumb_only)
4237                 {
4238                   stub_type = (parameters->options().shared()
4239                                || should_force_pic_veneer)
4240                     // PIC stubs.
4241                     ? ((may_use_blx
4242                         && (r_type == elfcpp::R_ARM_THM_CALL))
4243                        // V5T and above. Stub starts with ARM code, so
4244                        // we must be able to switch mode before
4245                        // reaching it, which is only possible for 'bl'
4246                        // (ie R_ARM_THM_CALL relocation).
4247                        ? arm_stub_long_branch_any_thumb_pic
4248                        // On V4T, use Thumb code only.
4249                        : arm_stub_long_branch_v4t_thumb_thumb_pic)
4250
4251                     // non-PIC stubs.
4252                     : ((may_use_blx
4253                         && (r_type == elfcpp::R_ARM_THM_CALL))
4254                        ? arm_stub_long_branch_any_any // V5T and above.
4255                        : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4256                 }
4257               else
4258                 {
4259                   stub_type = (parameters->options().shared()
4260                                || should_force_pic_veneer)
4261                     ? arm_stub_long_branch_thumb_only_pic       // PIC stub.
4262                     : arm_stub_long_branch_thumb_only;  // non-PIC stub.
4263                 }
4264             }
4265           else
4266             {
4267               // Thumb to arm.
4268              
4269               // FIXME: We should check that the input section is from an
4270               // object that has interwork enabled.
4271
4272               stub_type = (parameters->options().shared()
4273                            || should_force_pic_veneer)
4274                 // PIC stubs.
4275                 ? ((may_use_blx
4276                     && (r_type == elfcpp::R_ARM_THM_CALL))
4277                    ? arm_stub_long_branch_any_arm_pic   // V5T and above.
4278                    : arm_stub_long_branch_v4t_thumb_arm_pic)    // V4T.
4279
4280                 // non-PIC stubs.
4281                 : ((may_use_blx
4282                     && (r_type == elfcpp::R_ARM_THM_CALL))
4283                    ? arm_stub_long_branch_any_any       // V5T and above.
4284                    : arm_stub_long_branch_v4t_thumb_arm);       // V4T.
4285
4286               // Handle v4t short branches.
4287               if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4288                   && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4289                   && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4290                 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4291             }
4292         }
4293     }
4294   else if (r_type == elfcpp::R_ARM_CALL
4295            || r_type == elfcpp::R_ARM_JUMP24
4296            || r_type == elfcpp::R_ARM_PLT32)
4297     {
4298       if (target_is_thumb)
4299         {
4300           // Arm to thumb.
4301
4302           // FIXME: We should check that the input section is from an
4303           // object that has interwork enabled.
4304
4305           // We have an extra 2-bytes reach because of
4306           // the mode change (bit 24 (H) of BLX encoding).
4307           if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4308               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4309               || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4310               || (r_type == elfcpp::R_ARM_JUMP24)
4311               || (r_type == elfcpp::R_ARM_PLT32))
4312             {
4313               stub_type = (parameters->options().shared()
4314                            || should_force_pic_veneer)
4315                 // PIC stubs.
4316                 ? (may_use_blx
4317                    ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4318                    : arm_stub_long_branch_v4t_arm_thumb_pic)    // V4T stub.
4319
4320                 // non-PIC stubs.
4321                 : (may_use_blx
4322                    ? arm_stub_long_branch_any_any       // V5T and above.
4323                    : arm_stub_long_branch_v4t_arm_thumb);       // V4T.
4324             }
4325         }
4326       else
4327         {
4328           // Arm to arm.
4329           if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4330               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4331             {
4332               stub_type = (parameters->options().shared()
4333                            || should_force_pic_veneer)
4334                 ? arm_stub_long_branch_any_arm_pic      // PIC stubs.
4335                 : arm_stub_long_branch_any_any;         /// non-PIC.
4336             }
4337         }
4338     }
4339
4340   return stub_type;
4341 }
4342
4343 // Cortex_a8_stub methods.
4344
4345 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4346 // I is the position of the instruction template in the stub template.
4347
4348 uint16_t
4349 Cortex_a8_stub::do_thumb16_special(size_t i)
4350 {
4351   // The only use of this is to copy condition code from a conditional
4352   // branch being worked around to the corresponding conditional branch in
4353   // to the stub.
4354   gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4355               && i == 0);
4356   uint16_t data = this->stub_template()->insns()[i].data();
4357   gold_assert((data & 0xff00U) == 0xd000U);
4358   data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4359   return data;
4360 }
4361
4362 // Stub_factory methods.
4363
4364 Stub_factory::Stub_factory()
4365 {
4366   // The instruction template sequences are declared as static
4367   // objects and initialized first time the constructor runs.
4368  
4369   // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4370   // to reach the stub if necessary.
4371   static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4372     {
4373       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4374       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4375                                                 // dcd   R_ARM_ABS32(X)
4376     };
4377   
4378   // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4379   // available.
4380   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4381     {
4382       Insn_template::arm_insn(0xe59fc000),      // ldr   ip, [pc, #0]
4383       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4384       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4385                                                 // dcd   R_ARM_ABS32(X)
4386     };
4387   
4388   // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4389   static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4390     {
4391       Insn_template::thumb16_insn(0xb401),      // push {r0}
4392       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4393       Insn_template::thumb16_insn(0x4684),      // mov  ip, r0
4394       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4395       Insn_template::thumb16_insn(0x4760),      // bx   ip
4396       Insn_template::thumb16_insn(0xbf00),      // nop
4397       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4398                                                 // dcd  R_ARM_ABS32(X)
4399     };
4400   
4401   // V4T Thumb -> Thumb long branch stub. Using the stack is not
4402   // allowed.
4403   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4404     {
4405       Insn_template::thumb16_insn(0x4778),      // bx   pc
4406       Insn_template::thumb16_insn(0x46c0),      // nop
4407       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4408       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4409       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4410                                                 // dcd  R_ARM_ABS32(X)
4411     };
4412   
4413   // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4414   // available.
4415   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4416     {
4417       Insn_template::thumb16_insn(0x4778),      // bx   pc
4418       Insn_template::thumb16_insn(0x46c0),      // nop
4419       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4420       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4421                                                 // dcd   R_ARM_ABS32(X)
4422     };
4423   
4424   // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4425   // one, when the destination is close enough.
4426   static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4427     {
4428       Insn_template::thumb16_insn(0x4778),              // bx   pc
4429       Insn_template::thumb16_insn(0x46c0),              // nop
4430       Insn_template::arm_rel_insn(0xea000000, -8),      // b    (X-8)
4431     };
4432   
4433   // ARM/Thumb -> ARM long branch stub, PIC.  On V5T and above, use
4434   // blx to reach the stub if necessary.
4435   static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4436     {
4437       Insn_template::arm_insn(0xe59fc000),      // ldr   r12, [pc]
4438       Insn_template::arm_insn(0xe08ff00c),      // add   pc, pc, ip
4439       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4440                                                 // dcd   R_ARM_REL32(X-4)
4441     };
4442   
4443   // ARM/Thumb -> Thumb long branch stub, PIC.  On V5T and above, use
4444   // blx to reach the stub if necessary.  We can not add into pc;
4445   // it is not guaranteed to mode switch (different in ARMv6 and
4446   // ARMv7).
4447   static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4448     {
4449       Insn_template::arm_insn(0xe59fc004),      // ldr   r12, [pc, #4]
4450       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4451       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4452       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4453                                                 // dcd   R_ARM_REL32(X)
4454     };
4455   
4456   // V4T ARM -> ARM long branch stub, PIC.
4457   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4458     {
4459       Insn_template::arm_insn(0xe59fc004),      // ldr   ip, [pc, #4]
4460       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4461       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4462       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4463                                                 // dcd   R_ARM_REL32(X)
4464     };
4465   
4466   // V4T Thumb -> ARM long branch stub, PIC.
4467   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4468     {
4469       Insn_template::thumb16_insn(0x4778),      // bx   pc
4470       Insn_template::thumb16_insn(0x46c0),      // nop
4471       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4472       Insn_template::arm_insn(0xe08cf00f),      // add  pc, ip, pc
4473       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4474                                                 // dcd  R_ARM_REL32(X)
4475     };
4476   
4477   // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4478   // architectures.
4479   static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4480     {
4481       Insn_template::thumb16_insn(0xb401),      // push {r0}
4482       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4483       Insn_template::thumb16_insn(0x46fc),      // mov  ip, pc
4484       Insn_template::thumb16_insn(0x4484),      // add  ip, r0
4485       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4486       Insn_template::thumb16_insn(0x4760),      // bx   ip
4487       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4488                                                 // dcd  R_ARM_REL32(X)
4489     };
4490   
4491   // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4492   // allowed.
4493   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4494     {
4495       Insn_template::thumb16_insn(0x4778),      // bx   pc
4496       Insn_template::thumb16_insn(0x46c0),      // nop
4497       Insn_template::arm_insn(0xe59fc004),      // ldr  ip, [pc, #4]
4498       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4499       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4500       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4501                                                 // dcd  R_ARM_REL32(X)
4502     };
4503   
4504   // Cortex-A8 erratum-workaround stubs.
4505   
4506   // Stub used for conditional branches (which may be beyond +/-1MB away,
4507   // so we can't use a conditional branch to reach this stub).
4508   
4509   // original code:
4510   //
4511   //    b<cond> X
4512   // after:
4513   //
4514   static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4515     {
4516       Insn_template::thumb16_bcond_insn(0xd001),        //      b<cond>.n true
4517       Insn_template::thumb32_b_insn(0xf000b800, -4),    //      b.w after
4518       Insn_template::thumb32_b_insn(0xf000b800, -4)     // true:
4519                                                         //      b.w X
4520     };
4521   
4522   // Stub used for b.w and bl.w instructions.
4523   
4524   static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4525     {
4526       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4527     };
4528   
4529   static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4530     {
4531       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4532     };
4533   
4534   // Stub used for Thumb-2 blx.w instructions.  We modified the original blx.w
4535   // instruction (which switches to ARM mode) to point to this stub.  Jump to
4536   // the real destination using an ARM-mode branch.
4537   static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4538     {
4539       Insn_template::arm_rel_insn(0xea000000, -8)       // b dest
4540     };
4541
4542   // Stub used to provide an interworking for R_ARM_V4BX relocation
4543   // (bx r[n] instruction).
4544   static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4545     {
4546       Insn_template::arm_insn(0xe3100001),              // tst   r<n>, #1
4547       Insn_template::arm_insn(0x01a0f000),              // moveq pc, r<n>
4548       Insn_template::arm_insn(0xe12fff10)               // bx    r<n>
4549     };
4550
4551   // Fill in the stub template look-up table.  Stub templates are constructed
4552   // per instance of Stub_factory for fast look-up without locking
4553   // in a thread-enabled environment.
4554
4555   this->stub_templates_[arm_stub_none] =
4556     new Stub_template(arm_stub_none, NULL, 0);
4557
4558 #define DEF_STUB(x)     \
4559   do \
4560     { \
4561       size_t array_size \
4562         = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4563       Stub_type type = arm_stub_##x; \
4564       this->stub_templates_[type] = \
4565         new Stub_template(type, elf32_arm_stub_##x, array_size); \
4566     } \
4567   while (0);
4568
4569   DEF_STUBS
4570 #undef DEF_STUB
4571 }
4572
4573 // Stub_table methods.
4574
4575 // Removel all Cortex-A8 stub.
4576
4577 template<bool big_endian>
4578 void
4579 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4580 {
4581   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4582        p != this->cortex_a8_stubs_.end();
4583        ++p)
4584     delete p->second;
4585   this->cortex_a8_stubs_.clear();
4586 }
4587
4588 // Relocate one stub.  This is a helper for Stub_table::relocate_stubs().
4589
4590 template<bool big_endian>
4591 void
4592 Stub_table<big_endian>::relocate_stub(
4593     Stub* stub,
4594     const Relocate_info<32, big_endian>* relinfo,
4595     Target_arm<big_endian>* arm_target,
4596     Output_section* output_section,
4597     unsigned char* view,
4598     Arm_address address,
4599     section_size_type view_size)
4600 {
4601   const Stub_template* stub_template = stub->stub_template();
4602   if (stub_template->reloc_count() != 0)
4603     {
4604       // Adjust view to cover the stub only.
4605       section_size_type offset = stub->offset();
4606       section_size_type stub_size = stub_template->size();
4607       gold_assert(offset + stub_size <= view_size);
4608
4609       arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4610                                 address + offset, stub_size);
4611     }
4612 }
4613
4614 // Relocate all stubs in this stub table.
4615
4616 template<bool big_endian>
4617 void
4618 Stub_table<big_endian>::relocate_stubs(
4619     const Relocate_info<32, big_endian>* relinfo,
4620     Target_arm<big_endian>* arm_target,
4621     Output_section* output_section,
4622     unsigned char* view,
4623     Arm_address address,
4624     section_size_type view_size)
4625 {
4626   // If we are passed a view bigger than the stub table's.  we need to
4627   // adjust the view.
4628   gold_assert(address == this->address()
4629               && (view_size
4630                   == static_cast<section_size_type>(this->data_size())));
4631
4632   // Relocate all relocation stubs.
4633   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4634       p != this->reloc_stubs_.end();
4635       ++p)
4636     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4637                         address, view_size);
4638
4639   // Relocate all Cortex-A8 stubs.
4640   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4641        p != this->cortex_a8_stubs_.end();
4642        ++p)
4643     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4644                         address, view_size);
4645
4646   // Relocate all ARM V4BX stubs.
4647   for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4648        p != this->arm_v4bx_stubs_.end();
4649        ++p)
4650     {
4651       if (*p != NULL)
4652         this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4653                             address, view_size);
4654     }
4655 }
4656
4657 // Write out the stubs to file.
4658
4659 template<bool big_endian>
4660 void
4661 Stub_table<big_endian>::do_write(Output_file* of)
4662 {
4663   off_t offset = this->offset();
4664   const section_size_type oview_size =
4665     convert_to_section_size_type(this->data_size());
4666   unsigned char* const oview = of->get_output_view(offset, oview_size);
4667
4668   // Write relocation stubs.
4669   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4670       p != this->reloc_stubs_.end();
4671       ++p)
4672     {
4673       Reloc_stub* stub = p->second;
4674       Arm_address address = this->address() + stub->offset();
4675       gold_assert(address
4676                   == align_address(address,
4677                                    stub->stub_template()->alignment()));
4678       stub->write(oview + stub->offset(), stub->stub_template()->size(),
4679                   big_endian);
4680     }
4681
4682   // Write Cortex-A8 stubs.
4683   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4684        p != this->cortex_a8_stubs_.end();
4685        ++p)
4686     {
4687       Cortex_a8_stub* stub = p->second;
4688       Arm_address address = this->address() + stub->offset();
4689       gold_assert(address
4690                   == align_address(address,
4691                                    stub->stub_template()->alignment()));
4692       stub->write(oview + stub->offset(), stub->stub_template()->size(),
4693                   big_endian);
4694     }
4695
4696   // Write ARM V4BX relocation stubs.
4697   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4698        p != this->arm_v4bx_stubs_.end();
4699        ++p)
4700     {
4701       if (*p == NULL)
4702         continue;
4703
4704       Arm_address address = this->address() + (*p)->offset();
4705       gold_assert(address
4706                   == align_address(address,
4707                                    (*p)->stub_template()->alignment()));
4708       (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4709                   big_endian);
4710     }
4711
4712   of->write_output_view(this->offset(), oview_size, oview);
4713 }
4714
4715 // Update the data size and address alignment of the stub table at the end
4716 // of a relaxation pass.   Return true if either the data size or the
4717 // alignment changed in this relaxation pass.
4718
4719 template<bool big_endian>
4720 bool
4721 Stub_table<big_endian>::update_data_size_and_addralign()
4722 {
4723   off_t size = 0;
4724   unsigned addralign = 1;
4725
4726   // Go over all stubs in table to compute data size and address alignment.
4727   
4728   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4729       p != this->reloc_stubs_.end();
4730       ++p)
4731     {
4732       const Stub_template* stub_template = p->second->stub_template();
4733       addralign = std::max(addralign, stub_template->alignment());
4734       size = (align_address(size, stub_template->alignment())
4735               + stub_template->size());
4736     }
4737
4738   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4739        p != this->cortex_a8_stubs_.end();
4740        ++p)
4741     {
4742       const Stub_template* stub_template = p->second->stub_template();
4743       addralign = std::max(addralign, stub_template->alignment());
4744       size = (align_address(size, stub_template->alignment())
4745               + stub_template->size());
4746     }
4747
4748   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4749        p != this->arm_v4bx_stubs_.end();
4750        ++p)
4751     {
4752       if (*p == NULL)
4753         continue;
4754
4755       const Stub_template* stub_template = (*p)->stub_template();
4756       addralign = std::max(addralign, stub_template->alignment());
4757       size = (align_address(size, stub_template->alignment())
4758               + stub_template->size());
4759     }
4760
4761   // Check if either data size or alignment changed in this pass.
4762   // Update prev_data_size_ and prev_addralign_.  These will be used
4763   // as the current data size and address alignment for the next pass.
4764   bool changed = size != this->prev_data_size_;
4765   this->prev_data_size_ = size; 
4766
4767   if (addralign != this->prev_addralign_)
4768     changed = true;
4769   this->prev_addralign_ = addralign;
4770
4771   return changed;
4772 }
4773
4774 // Finalize the stubs.  This sets the offsets of the stubs within the stub
4775 // table.  It also marks all input sections needing Cortex-A8 workaround.
4776
4777 template<bool big_endian>
4778 void
4779 Stub_table<big_endian>::finalize_stubs()
4780 {
4781   off_t off = 0;
4782   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4783       p != this->reloc_stubs_.end();
4784       ++p)
4785     {
4786       Reloc_stub* stub = p->second;
4787       const Stub_template* stub_template = stub->stub_template();
4788       uint64_t stub_addralign = stub_template->alignment();
4789       off = align_address(off, stub_addralign);
4790       stub->set_offset(off);
4791       off += stub_template->size();
4792     }
4793
4794   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4795        p != this->cortex_a8_stubs_.end();
4796        ++p)
4797     {
4798       Cortex_a8_stub* stub = p->second;
4799       const Stub_template* stub_template = stub->stub_template();
4800       uint64_t stub_addralign = stub_template->alignment();
4801       off = align_address(off, stub_addralign);
4802       stub->set_offset(off);
4803       off += stub_template->size();
4804
4805       // Mark input section so that we can determine later if a code section
4806       // needs the Cortex-A8 workaround quickly.
4807       Arm_relobj<big_endian>* arm_relobj =
4808         Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
4809       arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
4810     }
4811
4812   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4813       p != this->arm_v4bx_stubs_.end();
4814       ++p)
4815     {
4816       if (*p == NULL)
4817         continue;
4818
4819       const Stub_template* stub_template = (*p)->stub_template();
4820       uint64_t stub_addralign = stub_template->alignment();
4821       off = align_address(off, stub_addralign);
4822       (*p)->set_offset(off);
4823       off += stub_template->size();
4824     }
4825
4826   gold_assert(off <= this->prev_data_size_);
4827 }
4828
4829 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
4830 // and VIEW_ADDRESS + VIEW_SIZE - 1.  VIEW points to the mapped address
4831 // of the address range seen by the linker.
4832
4833 template<bool big_endian>
4834 void
4835 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
4836     Target_arm<big_endian>* arm_target,
4837     unsigned char* view,
4838     Arm_address view_address,
4839     section_size_type view_size)
4840 {
4841   // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
4842   for (Cortex_a8_stub_list::const_iterator p =
4843          this->cortex_a8_stubs_.lower_bound(view_address);
4844        ((p != this->cortex_a8_stubs_.end())
4845         && (p->first < (view_address + view_size)));
4846        ++p)
4847     {
4848       // We do not store the THUMB bit in the LSB of either the branch address
4849       // or the stub offset.  There is no need to strip the LSB.
4850       Arm_address branch_address = p->first;
4851       const Cortex_a8_stub* stub = p->second;
4852       Arm_address stub_address = this->address() + stub->offset();
4853
4854       // Offset of the branch instruction relative to this view.
4855       section_size_type offset =
4856         convert_to_section_size_type(branch_address - view_address);
4857       gold_assert((offset + 4) <= view_size);
4858
4859       arm_target->apply_cortex_a8_workaround(stub, stub_address,
4860                                              view + offset, branch_address);
4861     }
4862 }
4863
4864 // Arm_input_section methods.
4865
4866 // Initialize an Arm_input_section.
4867
4868 template<bool big_endian>
4869 void
4870 Arm_input_section<big_endian>::init()
4871 {
4872   Relobj* relobj = this->relobj();
4873   unsigned int shndx = this->shndx();
4874
4875   // Cache these to speed up size and alignment queries.  It is too slow
4876   // to call section_addraglin and section_size every time.
4877   this->original_addralign_ = relobj->section_addralign(shndx);
4878   this->original_size_ = relobj->section_size(shndx);
4879
4880   // We want to make this look like the original input section after
4881   // output sections are finalized.
4882   Output_section* os = relobj->output_section(shndx);
4883   off_t offset = relobj->output_section_offset(shndx);
4884   gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
4885   this->set_address(os->address() + offset);
4886   this->set_file_offset(os->offset() + offset);
4887
4888   this->set_current_data_size(this->original_size_);
4889   this->finalize_data_size();
4890 }
4891
4892 template<bool big_endian>
4893 void
4894 Arm_input_section<big_endian>::do_write(Output_file* of)
4895 {
4896   // We have to write out the original section content.
4897   section_size_type section_size;
4898   const unsigned char* section_contents =
4899     this->relobj()->section_contents(this->shndx(), &section_size, false); 
4900   of->write(this->offset(), section_contents, section_size); 
4901
4902   // If this owns a stub table and it is not empty, write it.
4903   if (this->is_stub_table_owner() && !this->stub_table_->empty())
4904     this->stub_table_->write(of);
4905 }
4906
4907 // Finalize data size.
4908
4909 template<bool big_endian>
4910 void
4911 Arm_input_section<big_endian>::set_final_data_size()
4912 {
4913   // If this owns a stub table, finalize its data size as well.
4914   if (this->is_stub_table_owner())
4915     {
4916       uint64_t address = this->address();
4917
4918       // The stub table comes after the original section contents.
4919       address += this->original_size_;
4920       address = align_address(address, this->stub_table_->addralign());
4921       off_t offset = this->offset() + (address - this->address());
4922       this->stub_table_->set_address_and_file_offset(address, offset);
4923       address += this->stub_table_->data_size();
4924       gold_assert(address == this->address() + this->current_data_size());
4925     }
4926
4927   this->set_data_size(this->current_data_size());
4928 }
4929
4930 // Reset address and file offset.
4931
4932 template<bool big_endian>
4933 void
4934 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
4935 {
4936   // Size of the original input section contents.
4937   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
4938
4939   // If this is a stub table owner, account for the stub table size.
4940   if (this->is_stub_table_owner())
4941     {
4942       Stub_table<big_endian>* stub_table = this->stub_table_;
4943
4944       // Reset the stub table's address and file offset.  The
4945       // current data size for child will be updated after that.
4946       stub_table_->reset_address_and_file_offset();
4947       off = align_address(off, stub_table_->addralign());
4948       off += stub_table->current_data_size();
4949     }
4950
4951   this->set_current_data_size(off);
4952 }
4953
4954 // Arm_exidx_cantunwind methods.
4955
4956 // Write this to Output file OF for a fixed endianity.
4957
4958 template<bool big_endian>
4959 void
4960 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
4961 {
4962   off_t offset = this->offset();
4963   const section_size_type oview_size = 8;
4964   unsigned char* const oview = of->get_output_view(offset, oview_size);
4965   
4966   typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
4967   Valtype* wv = reinterpret_cast<Valtype*>(oview);
4968
4969   Output_section* os = this->relobj_->output_section(this->shndx_);
4970   gold_assert(os != NULL);
4971
4972   Arm_relobj<big_endian>* arm_relobj =
4973     Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
4974   Arm_address output_offset =
4975     arm_relobj->get_output_section_offset(this->shndx_);
4976   Arm_address section_start;
4977   if(output_offset != Arm_relobj<big_endian>::invalid_address)
4978     section_start = os->address() + output_offset;
4979   else
4980     {
4981       // Currently this only happens for a relaxed section.
4982       const Output_relaxed_input_section* poris =
4983         os->find_relaxed_input_section(this->relobj_, this->shndx_);
4984       gold_assert(poris != NULL);
4985       section_start = poris->address();
4986     }
4987
4988   // We always append this to the end of an EXIDX section.
4989   Arm_address output_address =
4990     section_start + this->relobj_->section_size(this->shndx_);
4991
4992   // Write out the entry.  The first word either points to the beginning
4993   // or after the end of a text section.  The second word is the special
4994   // EXIDX_CANTUNWIND value.
4995   uint32_t prel31_offset = output_address - this->address();
4996   if (utils::has_overflow<31>(offset))
4997     gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
4998   elfcpp::Swap<32, big_endian>::writeval(wv, prel31_offset & 0x7fffffffU);
4999   elfcpp::Swap<32, big_endian>::writeval(wv + 1, elfcpp::EXIDX_CANTUNWIND);
5000
5001   of->write_output_view(this->offset(), oview_size, oview);
5002 }
5003
5004 // Arm_exidx_merged_section methods.
5005
5006 // Constructor for Arm_exidx_merged_section.
5007 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5008 // SECTION_OFFSET_MAP points to a section offset map describing how
5009 // parts of the input section are mapped to output.  DELETED_BYTES is
5010 // the number of bytes deleted from the EXIDX input section.
5011
5012 Arm_exidx_merged_section::Arm_exidx_merged_section(
5013     const Arm_exidx_input_section& exidx_input_section,
5014     const Arm_exidx_section_offset_map& section_offset_map,
5015     uint32_t deleted_bytes)
5016   : Output_relaxed_input_section(exidx_input_section.relobj(),
5017                                  exidx_input_section.shndx(),
5018                                  exidx_input_section.addralign()),
5019     exidx_input_section_(exidx_input_section),
5020     section_offset_map_(section_offset_map)
5021 {
5022   // Fix size here so that we do not need to implement set_final_data_size.
5023   this->set_data_size(exidx_input_section.size() - deleted_bytes);
5024   this->fix_data_size();
5025 }
5026
5027 // Given an input OBJECT, an input section index SHNDX within that
5028 // object, and an OFFSET relative to the start of that input
5029 // section, return whether or not the corresponding offset within
5030 // the output section is known.  If this function returns true, it
5031 // sets *POUTPUT to the output offset.  The value -1 indicates that
5032 // this input offset is being discarded.
5033
5034 bool
5035 Arm_exidx_merged_section::do_output_offset(
5036     const Relobj* relobj,
5037     unsigned int shndx,
5038     section_offset_type offset,
5039     section_offset_type* poutput) const
5040 {
5041   // We only handle offsets for the original EXIDX input section.
5042   if (relobj != this->exidx_input_section_.relobj()
5043       || shndx != this->exidx_input_section_.shndx())
5044     return false;
5045
5046   section_offset_type section_size =
5047     convert_types<section_offset_type>(this->exidx_input_section_.size());
5048   if (offset < 0 || offset >= section_size)
5049     // Input offset is out of valid range.
5050     *poutput = -1;
5051   else
5052     {
5053       // We need to look up the section offset map to determine the output
5054       // offset.  Find the reference point in map that is first offset
5055       // bigger than or equal to this offset.
5056       Arm_exidx_section_offset_map::const_iterator p =
5057         this->section_offset_map_.lower_bound(offset);
5058
5059       // The section offset maps are build such that this should not happen if
5060       // input offset is in the valid range.
5061       gold_assert(p != this->section_offset_map_.end());
5062
5063       // We need to check if this is dropped.
5064      section_offset_type ref = p->first;
5065      section_offset_type mapped_ref = p->second;
5066
5067       if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5068         // Offset is present in output.
5069         *poutput = mapped_ref + (offset - ref);
5070       else
5071         // Offset is discarded owing to EXIDX entry merging.
5072         *poutput = -1;
5073     }
5074   
5075   return true;
5076 }
5077
5078 // Write this to output file OF.
5079
5080 void
5081 Arm_exidx_merged_section::do_write(Output_file* of)
5082 {
5083   // If we retain or discard the whole EXIDX input section,  we would
5084   // not be here.
5085   gold_assert(this->data_size() != this->exidx_input_section_.size()
5086               && this->data_size() != 0);
5087
5088   off_t offset = this->offset();
5089   const section_size_type oview_size = this->data_size();
5090   unsigned char* const oview = of->get_output_view(offset, oview_size);
5091   
5092   Output_section* os = this->relobj()->output_section(this->shndx());
5093   gold_assert(os != NULL);
5094
5095   // Get contents of EXIDX input section.
5096   section_size_type section_size;
5097   const unsigned char* section_contents =
5098     this->relobj()->section_contents(this->shndx(), &section_size, false); 
5099   gold_assert(section_size == this->exidx_input_section_.size());
5100
5101   // Go over spans of input offsets and write only those that are not
5102   // discarded.
5103   section_offset_type in_start = 0;
5104   section_offset_type out_start = 0;
5105   for(Arm_exidx_section_offset_map::const_iterator p =
5106         this->section_offset_map_.begin();
5107       p != this->section_offset_map_.end();
5108       ++p)
5109     {
5110       section_offset_type in_end = p->first;
5111       gold_assert(in_end >= in_start);
5112       section_offset_type out_end = p->second;
5113       size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5114       if (out_end != -1)
5115         {
5116           size_t out_chunk_size =
5117             convert_types<size_t>(out_end - out_start + 1);
5118           gold_assert(out_chunk_size == in_chunk_size);
5119           memcpy(oview + out_start, section_contents + in_start,
5120                  out_chunk_size);
5121           out_start += out_chunk_size;
5122         }
5123       in_start += in_chunk_size;
5124     }
5125
5126   gold_assert(convert_to_section_size_type(out_start) == oview_size);
5127   of->write_output_view(this->offset(), oview_size, oview);
5128 }
5129
5130 // Arm_exidx_fixup methods.
5131
5132 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5133 // is not an EXIDX_CANTUNWIND entry already.  The new EXIDX_CANTUNWIND entry
5134 // points to the end of the last seen EXIDX section.
5135
5136 void
5137 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5138 {
5139   if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5140       && this->last_input_section_ != NULL)
5141     {
5142       Relobj* relobj = this->last_input_section_->relobj();
5143       unsigned int text_shndx = this->last_input_section_->link();
5144       Arm_exidx_cantunwind* cantunwind =
5145         new Arm_exidx_cantunwind(relobj, text_shndx);
5146       this->exidx_output_section_->add_output_section_data(cantunwind);
5147       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5148     }
5149 }
5150
5151 // Process an EXIDX section entry in input.  Return whether this entry
5152 // can be deleted in the output.  SECOND_WORD in the second word of the
5153 // EXIDX entry.
5154
5155 bool
5156 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5157 {
5158   bool delete_entry;
5159   if (second_word == elfcpp::EXIDX_CANTUNWIND)
5160     {
5161       // Merge if previous entry is also an EXIDX_CANTUNWIND.
5162       delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5163       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5164     }
5165   else if ((second_word & 0x80000000) != 0)
5166     {
5167       // Inlined unwinding data.  Merge if equal to previous.
5168       delete_entry = (this->last_unwind_type_ == UT_INLINED_ENTRY
5169                       && this->last_inlined_entry_ == second_word);
5170       this->last_unwind_type_ = UT_INLINED_ENTRY;
5171       this->last_inlined_entry_ = second_word;
5172     }
5173   else
5174     {
5175       // Normal table entry.  In theory we could merge these too,
5176       // but duplicate entries are likely to be much less common.
5177       delete_entry = false;
5178       this->last_unwind_type_ = UT_NORMAL_ENTRY;
5179     }
5180   return delete_entry;
5181 }
5182
5183 // Update the current section offset map during EXIDX section fix-up.
5184 // If there is no map, create one.  INPUT_OFFSET is the offset of a
5185 // reference point, DELETED_BYTES is the number of deleted by in the
5186 // section so far.  If DELETE_ENTRY is true, the reference point and
5187 // all offsets after the previous reference point are discarded.
5188
5189 void
5190 Arm_exidx_fixup::update_offset_map(
5191     section_offset_type input_offset,
5192     section_size_type deleted_bytes,
5193     bool delete_entry)
5194 {
5195   if (this->section_offset_map_ == NULL)
5196     this->section_offset_map_ = new Arm_exidx_section_offset_map();
5197   section_offset_type output_offset = (delete_entry
5198                                        ? -1
5199                                        : input_offset - deleted_bytes);
5200   (*this->section_offset_map_)[input_offset] = output_offset;
5201 }
5202
5203 // Process EXIDX_INPUT_SECTION for EXIDX entry merging.  Return the number of
5204 // bytes deleted.  If some entries are merged, also store a pointer to a newly
5205 // created Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP.  The
5206 // caller owns the map and is responsible for releasing it after use.
5207
5208 template<bool big_endian>
5209 uint32_t
5210 Arm_exidx_fixup::process_exidx_section(
5211     const Arm_exidx_input_section* exidx_input_section,
5212     Arm_exidx_section_offset_map** psection_offset_map)
5213 {
5214   Relobj* relobj = exidx_input_section->relobj();
5215   unsigned shndx = exidx_input_section->shndx();
5216   section_size_type section_size;
5217   const unsigned char* section_contents =
5218     relobj->section_contents(shndx, &section_size, false);
5219
5220   if ((section_size % 8) != 0)
5221     {
5222       // Something is wrong with this section.  Better not touch it.
5223       gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5224                  relobj->name().c_str(), shndx);
5225       this->last_input_section_ = exidx_input_section;
5226       this->last_unwind_type_ = UT_NONE;
5227       return 0;
5228     }
5229   
5230   uint32_t deleted_bytes = 0;
5231   bool prev_delete_entry = false;
5232   gold_assert(this->section_offset_map_ == NULL);
5233
5234   for (section_size_type i = 0; i < section_size; i += 8)
5235     {
5236       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5237       const Valtype* wv =
5238           reinterpret_cast<const Valtype*>(section_contents + i + 4);
5239       uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5240
5241       bool delete_entry = this->process_exidx_entry(second_word);
5242
5243       // Entry deletion causes changes in output offsets.  We use a std::map
5244       // to record these.  And entry (x, y) means input offset x
5245       // is mapped to output offset y.  If y is invalid_offset, then x is
5246       // dropped in the output.  Because of the way std::map::lower_bound
5247       // works, we record the last offset in a region w.r.t to keeping or
5248       // dropping.  If there is no entry (x0, y0) for an input offset x0,
5249       // the output offset y0 of it is determined by the output offset y1 of
5250       // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5251       // in the map.  If y1 is not -1, then y0 = y1 + x0 - x1.  Othewise, y1
5252       // y0 is also -1.
5253       if (delete_entry != prev_delete_entry && i != 0)
5254         this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5255
5256       // Update total deleted bytes for this entry.
5257       if (delete_entry)
5258         deleted_bytes += 8;
5259
5260       prev_delete_entry = delete_entry;
5261     }
5262   
5263   // If section offset map is not NULL, make an entry for the end of
5264   // section.
5265   if (this->section_offset_map_ != NULL)
5266     update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5267
5268   *psection_offset_map = this->section_offset_map_;
5269   this->section_offset_map_ = NULL;
5270   this->last_input_section_ = exidx_input_section;
5271   
5272   // Set the first output text section so that we can link the EXIDX output
5273   // section to it.  Ignore any EXIDX input section that is completely merged.
5274   if (this->first_output_text_section_ == NULL
5275       && deleted_bytes != section_size)
5276     {
5277       unsigned int link = exidx_input_section->link();
5278       Output_section* os = relobj->output_section(link);
5279       gold_assert(os != NULL);
5280       this->first_output_text_section_ = os;
5281     }
5282
5283   return deleted_bytes;
5284 }
5285
5286 // Arm_output_section methods.
5287
5288 // Create a stub group for input sections from BEGIN to END.  OWNER
5289 // points to the input section to be the owner a new stub table.
5290
5291 template<bool big_endian>
5292 void
5293 Arm_output_section<big_endian>::create_stub_group(
5294   Input_section_list::const_iterator begin,
5295   Input_section_list::const_iterator end,
5296   Input_section_list::const_iterator owner,
5297   Target_arm<big_endian>* target,
5298   std::vector<Output_relaxed_input_section*>* new_relaxed_sections)
5299 {
5300   // We use a different kind of relaxed section in an EXIDX section.
5301   // The static casting from Output_relaxed_input_section to
5302   // Arm_input_section is invalid in an EXIDX section.  We are okay
5303   // because we should not be calling this for an EXIDX section. 
5304   gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5305
5306   // Currently we convert ordinary input sections into relaxed sections only
5307   // at this point but we may want to support creating relaxed input section
5308   // very early.  So we check here to see if owner is already a relaxed
5309   // section.
5310   
5311   Arm_input_section<big_endian>* arm_input_section;
5312   if (owner->is_relaxed_input_section())
5313     {
5314       arm_input_section =
5315         Arm_input_section<big_endian>::as_arm_input_section(
5316           owner->relaxed_input_section());
5317     }
5318   else
5319     {
5320       gold_assert(owner->is_input_section());
5321       // Create a new relaxed input section.
5322       arm_input_section =
5323         target->new_arm_input_section(owner->relobj(), owner->shndx());
5324       new_relaxed_sections->push_back(arm_input_section);
5325     }
5326
5327   // Create a stub table.
5328   Stub_table<big_endian>* stub_table =
5329     target->new_stub_table(arm_input_section);
5330
5331   arm_input_section->set_stub_table(stub_table);
5332   
5333   Input_section_list::const_iterator p = begin;
5334   Input_section_list::const_iterator prev_p;
5335
5336   // Look for input sections or relaxed input sections in [begin ... end].
5337   do
5338     {
5339       if (p->is_input_section() || p->is_relaxed_input_section())
5340         {
5341           // The stub table information for input sections live
5342           // in their objects.
5343           Arm_relobj<big_endian>* arm_relobj =
5344             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5345           arm_relobj->set_stub_table(p->shndx(), stub_table);
5346         }
5347       prev_p = p++;
5348     }
5349   while (prev_p != end);
5350 }
5351
5352 // Group input sections for stub generation.  GROUP_SIZE is roughly the limit
5353 // of stub groups.  We grow a stub group by adding input section until the
5354 // size is just below GROUP_SIZE.  The last input section will be converted
5355 // into a stub table.  If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5356 // input section after the stub table, effectively double the group size.
5357 // 
5358 // This is similar to the group_sections() function in elf32-arm.c but is
5359 // implemented differently.
5360
5361 template<bool big_endian>
5362 void
5363 Arm_output_section<big_endian>::group_sections(
5364     section_size_type group_size,
5365     bool stubs_always_after_branch,
5366     Target_arm<big_endian>* target)
5367 {
5368   // We only care about sections containing code.
5369   if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
5370     return;
5371
5372   // States for grouping.
5373   typedef enum
5374   {
5375     // No group is being built.
5376     NO_GROUP,
5377     // A group is being built but the stub table is not found yet.
5378     // We keep group a stub group until the size is just under GROUP_SIZE.
5379     // The last input section in the group will be used as the stub table.
5380     FINDING_STUB_SECTION,
5381     // A group is being built and we have already found a stub table.
5382     // We enter this state to grow a stub group by adding input section
5383     // after the stub table.  This effectively doubles the group size.
5384     HAS_STUB_SECTION
5385   } State;
5386
5387   // Any newly created relaxed sections are stored here.
5388   std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5389
5390   State state = NO_GROUP;
5391   section_size_type off = 0;
5392   section_size_type group_begin_offset = 0;
5393   section_size_type group_end_offset = 0;
5394   section_size_type stub_table_end_offset = 0;
5395   Input_section_list::const_iterator group_begin =
5396     this->input_sections().end();
5397   Input_section_list::const_iterator stub_table =
5398     this->input_sections().end();
5399   Input_section_list::const_iterator group_end = this->input_sections().end();
5400   for (Input_section_list::const_iterator p = this->input_sections().begin();
5401        p != this->input_sections().end();
5402        ++p)
5403     {
5404       section_size_type section_begin_offset =
5405         align_address(off, p->addralign());
5406       section_size_type section_end_offset =
5407         section_begin_offset + p->data_size(); 
5408       
5409       // Check to see if we should group the previously seens sections.
5410       switch (state)
5411         {
5412         case NO_GROUP:
5413           break;
5414
5415         case FINDING_STUB_SECTION:
5416           // Adding this section makes the group larger than GROUP_SIZE.
5417           if (section_end_offset - group_begin_offset >= group_size)
5418             {
5419               if (stubs_always_after_branch)
5420                 {       
5421                   gold_assert(group_end != this->input_sections().end());
5422                   this->create_stub_group(group_begin, group_end, group_end,
5423                                           target, &new_relaxed_sections);
5424                   state = NO_GROUP;
5425                 }
5426               else
5427                 {
5428                   // But wait, there's more!  Input sections up to
5429                   // stub_group_size bytes after the stub table can be
5430                   // handled by it too.
5431                   state = HAS_STUB_SECTION;
5432                   stub_table = group_end;
5433                   stub_table_end_offset = group_end_offset;
5434                 }
5435             }
5436             break;
5437
5438         case HAS_STUB_SECTION:
5439           // Adding this section makes the post stub-section group larger
5440           // than GROUP_SIZE.
5441           if (section_end_offset - stub_table_end_offset >= group_size)
5442            {
5443              gold_assert(group_end != this->input_sections().end());
5444              this->create_stub_group(group_begin, group_end, stub_table,
5445                                      target, &new_relaxed_sections);
5446              state = NO_GROUP;
5447            }
5448            break;
5449
5450           default:
5451             gold_unreachable();
5452         }       
5453
5454       // If we see an input section and currently there is no group, start
5455       // a new one.  Skip any empty sections.
5456       if ((p->is_input_section() || p->is_relaxed_input_section())
5457           && (p->relobj()->section_size(p->shndx()) != 0))
5458         {
5459           if (state == NO_GROUP)
5460             {
5461               state = FINDING_STUB_SECTION;
5462               group_begin = p;
5463               group_begin_offset = section_begin_offset;
5464             }
5465
5466           // Keep track of the last input section seen.
5467           group_end = p;
5468           group_end_offset = section_end_offset;
5469         }
5470
5471       off = section_end_offset;
5472     }
5473
5474   // Create a stub group for any ungrouped sections.
5475   if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5476     {
5477       gold_assert(group_end != this->input_sections().end());
5478       this->create_stub_group(group_begin, group_end,
5479                               (state == FINDING_STUB_SECTION
5480                                ? group_end
5481                                : stub_table),
5482                                target, &new_relaxed_sections);
5483     }
5484
5485   // Convert input section into relaxed input section in a batch.
5486   if (!new_relaxed_sections.empty())
5487     this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5488
5489   // Update the section offsets
5490   for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5491     {
5492       Arm_relobj<big_endian>* arm_relobj =
5493         Arm_relobj<big_endian>::as_arm_relobj(
5494           new_relaxed_sections[i]->relobj());
5495       unsigned int shndx = new_relaxed_sections[i]->shndx();
5496       // Tell Arm_relobj that this input section is converted.
5497       arm_relobj->convert_input_section_to_relaxed_section(shndx);
5498     }
5499 }
5500
5501 // Append non empty text sections in this to LIST in ascending
5502 // order of their position in this.
5503
5504 template<bool big_endian>
5505 void
5506 Arm_output_section<big_endian>::append_text_sections_to_list(
5507     Text_section_list* list)
5508 {
5509   // We only care about text sections.
5510   if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
5511     return;
5512
5513   gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5514
5515   for (Input_section_list::const_iterator p = this->input_sections().begin();
5516        p != this->input_sections().end();
5517        ++p)
5518     {
5519       // We only care about plain or relaxed input sections.  We also
5520       // ignore any merged sections.
5521       if ((p->is_input_section() || p->is_relaxed_input_section())
5522           && p->data_size() != 0)
5523         list->push_back(Text_section_list::value_type(p->relobj(),
5524                                                       p->shndx()));
5525     }
5526 }
5527
5528 template<bool big_endian>
5529 void
5530 Arm_output_section<big_endian>::fix_exidx_coverage(
5531     Layout* layout,
5532     const Text_section_list& sorted_text_sections,
5533     Symbol_table* symtab)
5534 {
5535   // We should only do this for the EXIDX output section.
5536   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5537
5538   // We don't want the relaxation loop to undo these changes, so we discard
5539   // the current saved states and take another one after the fix-up.
5540   this->discard_states();
5541
5542   // Remove all input sections.
5543   uint64_t address = this->address();
5544   typedef std::list<Simple_input_section> Simple_input_section_list;
5545   Simple_input_section_list input_sections;
5546   this->reset_address_and_file_offset();
5547   this->get_input_sections(address, std::string(""), &input_sections);
5548
5549   if (!this->input_sections().empty())
5550     gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5551   
5552   // Go through all the known input sections and record them.
5553   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5554   Section_id_set known_input_sections;
5555   for (Simple_input_section_list::const_iterator p = input_sections.begin();
5556        p != input_sections.end();
5557        ++p)
5558     {
5559       // This should never happen.  At this point, we should only see
5560       // plain EXIDX input sections.
5561       gold_assert(!p->is_relaxed_input_section());
5562       known_input_sections.insert(Section_id(p->relobj(), p->shndx()));
5563     }
5564
5565   Arm_exidx_fixup exidx_fixup(this);
5566
5567   // Go over the sorted text sections.
5568   Section_id_set processed_input_sections;
5569   for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5570        p != sorted_text_sections.end();
5571        ++p)
5572     {
5573       Relobj* relobj = p->first;
5574       unsigned int shndx = p->second;
5575
5576       Arm_relobj<big_endian>* arm_relobj =
5577          Arm_relobj<big_endian>::as_arm_relobj(relobj);
5578       const Arm_exidx_input_section* exidx_input_section =
5579          arm_relobj->exidx_input_section_by_link(shndx);
5580
5581       // If this text section has no EXIDX section, force an EXIDX_CANTUNWIND
5582       // entry pointing to the end of the last seen EXIDX section.
5583       if (exidx_input_section == NULL)
5584         {
5585           exidx_fixup.add_exidx_cantunwind_as_needed();
5586           continue;
5587         }
5588
5589       Relobj* exidx_relobj = exidx_input_section->relobj();
5590       unsigned int exidx_shndx = exidx_input_section->shndx();
5591       Section_id sid(exidx_relobj, exidx_shndx);
5592       if (known_input_sections.find(sid) == known_input_sections.end())
5593         {
5594           // This is odd.  We have not seen this EXIDX input section before.
5595           // We cannot do fix-up.  If we saw a SECTIONS clause in a script,
5596           // issue a warning instead.  We assume the user knows what he
5597           // or she is doing.  Otherwise, this is an error.
5598           if (layout->script_options()->saw_sections_clause())
5599             gold_warning(_("unwinding may not work because EXIDX input section"
5600                            " %u of %s is not in EXIDX output section"),
5601                          exidx_shndx, exidx_relobj->name().c_str());
5602           else
5603             gold_error(_("unwinding may not work because EXIDX input section"
5604                          " %u of %s is not in EXIDX output section"),
5605                        exidx_shndx, exidx_relobj->name().c_str());
5606
5607           exidx_fixup.add_exidx_cantunwind_as_needed();
5608           continue;
5609         }
5610
5611       // Fix up coverage and append input section to output data list.
5612       Arm_exidx_section_offset_map* section_offset_map = NULL;
5613       uint32_t deleted_bytes =
5614         exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5615                                                       &section_offset_map);
5616
5617       if (deleted_bytes == exidx_input_section->size())
5618         {
5619           // The whole EXIDX section got merged.  Remove it from output.
5620           gold_assert(section_offset_map == NULL);
5621           exidx_relobj->set_output_section(exidx_shndx, NULL);
5622
5623           // All local symbols defined in this input section will be dropped.
5624           // We need to adjust output local symbol count.
5625           arm_relobj->set_output_local_symbol_count_needs_update();
5626         }
5627       else if (deleted_bytes > 0)
5628         {
5629           // Some entries are merged.  We need to convert this EXIDX input
5630           // section into a relaxed section.
5631           gold_assert(section_offset_map != NULL);
5632           Arm_exidx_merged_section* merged_section =
5633             new Arm_exidx_merged_section(*exidx_input_section,
5634                                          *section_offset_map, deleted_bytes);
5635           this->add_relaxed_input_section(merged_section);
5636           arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5637
5638           // All local symbols defined in discarded portions of this input
5639           // section will be dropped.  We need to adjust output local symbol
5640           // count.
5641           arm_relobj->set_output_local_symbol_count_needs_update();
5642         }
5643       else
5644         {
5645           // Just add back the EXIDX input section.
5646           gold_assert(section_offset_map == NULL);
5647           Output_section::Simple_input_section sis(exidx_relobj, exidx_shndx);
5648           this->add_simple_input_section(sis, exidx_input_section->size(),
5649                                          exidx_input_section->addralign());
5650         }
5651
5652       processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx)); 
5653     }
5654
5655   // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5656   exidx_fixup.add_exidx_cantunwind_as_needed();
5657
5658   // Remove any known EXIDX input sections that are not processed.
5659   for (Simple_input_section_list::const_iterator p = input_sections.begin();
5660        p != input_sections.end();
5661        ++p)
5662     {
5663       if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5664           == processed_input_sections.end())
5665         {
5666           // We only discard a known EXIDX section because its linked
5667           // text section has been folded by ICF.
5668           Arm_relobj<big_endian>* arm_relobj =
5669             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5670           const Arm_exidx_input_section* exidx_input_section =
5671             arm_relobj->exidx_input_section_by_shndx(p->shndx());
5672           gold_assert(exidx_input_section != NULL);
5673           unsigned int text_shndx = exidx_input_section->link();
5674           gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5675
5676           // Remove this from link.
5677           p->relobj()->set_output_section(p->shndx(), NULL);
5678         }
5679     }
5680     
5681   // Link exidx output section to the first seen output section and
5682   // set correct entry size.
5683   this->set_link_section(exidx_fixup.first_output_text_section());
5684   this->set_entsize(8);
5685
5686   // Make changes permanent.
5687   this->save_states();
5688   this->set_section_offsets_need_adjustment();
5689 }
5690
5691 // Arm_relobj methods.
5692
5693 // Determine if an input section is scannable for stub processing.  SHDR is
5694 // the header of the section and SHNDX is the section index.  OS is the output
5695 // section for the input section and SYMTAB is the global symbol table used to
5696 // look up ICF information.
5697
5698 template<bool big_endian>
5699 bool
5700 Arm_relobj<big_endian>::section_is_scannable(
5701     const elfcpp::Shdr<32, big_endian>& shdr,
5702     unsigned int shndx,
5703     const Output_section* os,
5704     const Symbol_table *symtab)
5705 {
5706   // Skip any empty sections, unallocated sections or sections whose
5707   // type are not SHT_PROGBITS.
5708   if (shdr.get_sh_size() == 0
5709       || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
5710       || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
5711     return false;
5712
5713   // Skip any discarded or ICF'ed sections.
5714   if (os == NULL || symtab->is_section_folded(this, shndx))
5715     return false;
5716
5717   // If this requires special offset handling, check to see if it is
5718   // a relaxed section.  If this is not, then it is a merged section that
5719   // we cannot handle.
5720   if (this->is_output_section_offset_invalid(shndx))
5721     {
5722       const Output_relaxed_input_section* poris =
5723         os->find_relaxed_input_section(this, shndx);
5724       if (poris == NULL)
5725         return false;
5726     }
5727
5728   return true;
5729 }
5730
5731 // Determine if we want to scan the SHNDX-th section for relocation stubs.
5732 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
5733
5734 template<bool big_endian>
5735 bool
5736 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
5737     const elfcpp::Shdr<32, big_endian>& shdr,
5738     const Relobj::Output_sections& out_sections,
5739     const Symbol_table *symtab,
5740     const unsigned char* pshdrs)
5741 {
5742   unsigned int sh_type = shdr.get_sh_type();
5743   if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
5744     return false;
5745
5746   // Ignore empty section.
5747   off_t sh_size = shdr.get_sh_size();
5748   if (sh_size == 0)
5749     return false;
5750
5751   // Ignore reloc section with unexpected symbol table.  The
5752   // error will be reported in the final link.
5753   if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
5754     return false;
5755
5756   unsigned int reloc_size;
5757   if (sh_type == elfcpp::SHT_REL)
5758     reloc_size = elfcpp::Elf_sizes<32>::rel_size;
5759   else
5760     reloc_size = elfcpp::Elf_sizes<32>::rela_size;
5761
5762   // Ignore reloc section with unexpected entsize or uneven size.
5763   // The error will be reported in the final link.
5764   if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
5765     return false;
5766
5767   // Ignore reloc section with bad info.  This error will be
5768   // reported in the final link.
5769   unsigned int index = this->adjust_shndx(shdr.get_sh_info());
5770   if (index >= this->shnum())
5771     return false;
5772
5773   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
5774   const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
5775   return this->section_is_scannable(text_shdr, index,
5776                                    out_sections[index], symtab);
5777 }
5778
5779 // Return the output address of either a plain input section or a relaxed
5780 // input section.  SHNDX is the section index.  We define and use this
5781 // instead of calling Output_section::output_address because that is slow
5782 // for large output.
5783
5784 template<bool big_endian>
5785 Arm_address
5786 Arm_relobj<big_endian>::simple_input_section_output_address(
5787     unsigned int shndx,
5788     Output_section* os)
5789 {
5790   if (this->is_output_section_offset_invalid(shndx))
5791     {
5792       const Output_relaxed_input_section* poris =
5793         os->find_relaxed_input_section(this, shndx);
5794       // We do not handle merged sections here.
5795       gold_assert(poris != NULL);
5796       return poris->address();
5797     }
5798   else
5799     return os->address() + this->get_output_section_offset(shndx);
5800 }
5801
5802 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
5803 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
5804
5805 template<bool big_endian>
5806 bool
5807 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
5808     const elfcpp::Shdr<32, big_endian>& shdr,
5809     unsigned int shndx,
5810     Output_section* os,
5811     const Symbol_table* symtab)
5812 {
5813   if (!this->section_is_scannable(shdr, shndx, os, symtab))
5814     return false;
5815
5816   // If the section does not cross any 4K-boundaries, it does not need to
5817   // be scanned.
5818   Arm_address address = this->simple_input_section_output_address(shndx, os);
5819   if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
5820     return false;
5821
5822   return true;
5823 }
5824
5825 // Scan a section for Cortex-A8 workaround.
5826
5827 template<bool big_endian>
5828 void
5829 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
5830     const elfcpp::Shdr<32, big_endian>& shdr,
5831     unsigned int shndx,
5832     Output_section* os,
5833     Target_arm<big_endian>* arm_target)
5834 {
5835   // Look for the first mapping symbol in this section.  It should be
5836   // at (shndx, 0).
5837   Mapping_symbol_position section_start(shndx, 0);
5838   typename Mapping_symbols_info::const_iterator p =
5839     this->mapping_symbols_info_.lower_bound(section_start);
5840
5841   // There are no mapping symbols for this section.  Treat it as a data-only
5842   // section.
5843   if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
5844     return;
5845
5846   Arm_address output_address =
5847     this->simple_input_section_output_address(shndx, os);
5848
5849   // Get the section contents.
5850   section_size_type input_view_size = 0;
5851   const unsigned char* input_view =
5852     this->section_contents(shndx, &input_view_size, false);
5853
5854   // We need to go through the mapping symbols to determine what to
5855   // scan.  There are two reasons.  First, we should look at THUMB code and
5856   // THUMB code only.  Second, we only want to look at the 4K-page boundary
5857   // to speed up the scanning.
5858   
5859   while (p != this->mapping_symbols_info_.end()
5860         && p->first.first == shndx)
5861     {
5862       typename Mapping_symbols_info::const_iterator next =
5863         this->mapping_symbols_info_.upper_bound(p->first);
5864
5865       // Only scan part of a section with THUMB code.
5866       if (p->second == 't')
5867         {
5868           // Determine the end of this range.
5869           section_size_type span_start =
5870             convert_to_section_size_type(p->first.second);
5871           section_size_type span_end;
5872           if (next != this->mapping_symbols_info_.end()
5873               && next->first.first == shndx)
5874             span_end = convert_to_section_size_type(next->first.second);
5875           else
5876             span_end = convert_to_section_size_type(shdr.get_sh_size());
5877           
5878           if (((span_start + output_address) & ~0xfffUL)
5879               != ((span_end + output_address - 1) & ~0xfffUL))
5880             {
5881               arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
5882                                                           span_start, span_end,
5883                                                           input_view,
5884                                                           output_address);
5885             }
5886         }
5887
5888       p = next; 
5889     }
5890 }
5891
5892 // Scan relocations for stub generation.
5893
5894 template<bool big_endian>
5895 void
5896 Arm_relobj<big_endian>::scan_sections_for_stubs(
5897     Target_arm<big_endian>* arm_target,
5898     const Symbol_table* symtab,
5899     const Layout* layout)
5900 {
5901   unsigned int shnum = this->shnum();
5902   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
5903
5904   // Read the section headers.
5905   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
5906                                                shnum * shdr_size,
5907                                                true, true);
5908
5909   // To speed up processing, we set up hash tables for fast lookup of
5910   // input offsets to output addresses.
5911   this->initialize_input_to_output_maps();
5912
5913   const Relobj::Output_sections& out_sections(this->output_sections());
5914
5915   Relocate_info<32, big_endian> relinfo;
5916   relinfo.symtab = symtab;
5917   relinfo.layout = layout;
5918   relinfo.object = this;
5919
5920   // Do relocation stubs scanning.
5921   const unsigned char* p = pshdrs + shdr_size;
5922   for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
5923     {
5924       const elfcpp::Shdr<32, big_endian> shdr(p);
5925       if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
5926                                                   pshdrs))
5927         {
5928           unsigned int index = this->adjust_shndx(shdr.get_sh_info());
5929           Arm_address output_offset = this->get_output_section_offset(index);
5930           Arm_address output_address;
5931           if(output_offset != invalid_address)
5932             output_address = out_sections[index]->address() + output_offset;
5933           else
5934             {
5935               // Currently this only happens for a relaxed section.
5936               const Output_relaxed_input_section* poris =
5937               out_sections[index]->find_relaxed_input_section(this, index);
5938               gold_assert(poris != NULL);
5939               output_address = poris->address();
5940             }
5941
5942           // Get the relocations.
5943           const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
5944                                                         shdr.get_sh_size(),
5945                                                         true, false);
5946
5947           // Get the section contents.  This does work for the case in which
5948           // we modify the contents of an input section.  We need to pass the
5949           // output view under such circumstances.
5950           section_size_type input_view_size = 0;
5951           const unsigned char* input_view =
5952             this->section_contents(index, &input_view_size, false);
5953
5954           relinfo.reloc_shndx = i;
5955           relinfo.data_shndx = index;
5956           unsigned int sh_type = shdr.get_sh_type();
5957           unsigned int reloc_size;
5958           if (sh_type == elfcpp::SHT_REL)
5959             reloc_size = elfcpp::Elf_sizes<32>::rel_size;
5960           else
5961             reloc_size = elfcpp::Elf_sizes<32>::rela_size;
5962
5963           Output_section* os = out_sections[index];
5964           arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
5965                                              shdr.get_sh_size() / reloc_size,
5966                                              os,
5967                                              output_offset == invalid_address,
5968                                              input_view, output_address,
5969                                              input_view_size);
5970         }
5971     }
5972
5973   // Do Cortex-A8 erratum stubs scanning.  This has to be done for a section
5974   // after its relocation section, if there is one, is processed for
5975   // relocation stubs.  Merging this loop with the one above would have been
5976   // complicated since we would have had to make sure that relocation stub
5977   // scanning is done first.
5978   if (arm_target->fix_cortex_a8())
5979     {
5980       const unsigned char* p = pshdrs + shdr_size;
5981       for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
5982         {
5983           const elfcpp::Shdr<32, big_endian> shdr(p);
5984           if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
5985                                                           out_sections[i],
5986                                                           symtab))
5987             this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
5988                                                      arm_target);
5989         }
5990     }
5991
5992   // After we've done the relocations, we release the hash tables,
5993   // since we no longer need them.
5994   this->free_input_to_output_maps();
5995 }
5996
5997 // Count the local symbols.  The ARM backend needs to know if a symbol
5998 // is a THUMB function or not.  For global symbols, it is easy because
5999 // the Symbol object keeps the ELF symbol type.  For local symbol it is
6000 // harder because we cannot access this information.   So we override the
6001 // do_count_local_symbol in parent and scan local symbols to mark
6002 // THUMB functions.  This is not the most efficient way but I do not want to
6003 // slow down other ports by calling a per symbol targer hook inside
6004 // Sized_relobj<size, big_endian>::do_count_local_symbols. 
6005
6006 template<bool big_endian>
6007 void
6008 Arm_relobj<big_endian>::do_count_local_symbols(
6009     Stringpool_template<char>* pool,
6010     Stringpool_template<char>* dynpool)
6011 {
6012   // We need to fix-up the values of any local symbols whose type are
6013   // STT_ARM_TFUNC.
6014   
6015   // Ask parent to count the local symbols.
6016   Sized_relobj<32, big_endian>::do_count_local_symbols(pool, dynpool);
6017   const unsigned int loccount = this->local_symbol_count();
6018   if (loccount == 0)
6019     return;
6020
6021   // Intialize the thumb function bit-vector.
6022   std::vector<bool> empty_vector(loccount, false);
6023   this->local_symbol_is_thumb_function_.swap(empty_vector);
6024
6025   // Read the symbol table section header.
6026   const unsigned int symtab_shndx = this->symtab_shndx();
6027   elfcpp::Shdr<32, big_endian>
6028       symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6029   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6030
6031   // Read the local symbols.
6032   const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6033   gold_assert(loccount == symtabshdr.get_sh_info());
6034   off_t locsize = loccount * sym_size;
6035   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6036                                               locsize, true, true);
6037
6038   // For mapping symbol processing, we need to read the symbol names.
6039   unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6040   if (strtab_shndx >= this->shnum())
6041     {
6042       this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6043       return;
6044     }
6045
6046   elfcpp::Shdr<32, big_endian>
6047     strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6048   if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6049     {
6050       this->error(_("symbol table name section has wrong type: %u"),
6051                   static_cast<unsigned int>(strtabshdr.get_sh_type()));
6052       return;
6053     }
6054   const char* pnames =
6055     reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6056                                                  strtabshdr.get_sh_size(),
6057                                                  false, false));
6058
6059   // Loop over the local symbols and mark any local symbols pointing
6060   // to THUMB functions.
6061
6062   // Skip the first dummy symbol.
6063   psyms += sym_size;
6064   typename Sized_relobj<32, big_endian>::Local_values* plocal_values =
6065     this->local_values();
6066   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6067     {
6068       elfcpp::Sym<32, big_endian> sym(psyms);
6069       elfcpp::STT st_type = sym.get_st_type();
6070       Symbol_value<32>& lv((*plocal_values)[i]);
6071       Arm_address input_value = lv.input_value();
6072
6073       // Check to see if this is a mapping symbol.
6074       const char* sym_name = pnames + sym.get_st_name();
6075       if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6076         {
6077           unsigned int input_shndx = sym.get_st_shndx();  
6078
6079           // Strip of LSB in case this is a THUMB symbol.
6080           Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6081           this->mapping_symbols_info_[msp] = sym_name[1];
6082         }
6083
6084       if (st_type == elfcpp::STT_ARM_TFUNC
6085           || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6086         {
6087           // This is a THUMB function.  Mark this and canonicalize the
6088           // symbol value by setting LSB.
6089           this->local_symbol_is_thumb_function_[i] = true;
6090           if ((input_value & 1) == 0)
6091             lv.set_input_value(input_value | 1);
6092         }
6093     }
6094 }
6095
6096 // Relocate sections.
6097 template<bool big_endian>
6098 void
6099 Arm_relobj<big_endian>::do_relocate_sections(
6100     const Symbol_table* symtab,
6101     const Layout* layout,
6102     const unsigned char* pshdrs,
6103     typename Sized_relobj<32, big_endian>::Views* pviews)
6104 {
6105   // Call parent to relocate sections.
6106   Sized_relobj<32, big_endian>::do_relocate_sections(symtab, layout, pshdrs,
6107                                                      pviews); 
6108
6109   // We do not generate stubs if doing a relocatable link.
6110   if (parameters->options().relocatable())
6111     return;
6112
6113   // Relocate stub tables.
6114   unsigned int shnum = this->shnum();
6115
6116   Target_arm<big_endian>* arm_target =
6117     Target_arm<big_endian>::default_target();
6118
6119   Relocate_info<32, big_endian> relinfo;
6120   relinfo.symtab = symtab;
6121   relinfo.layout = layout;
6122   relinfo.object = this;
6123
6124   for (unsigned int i = 1; i < shnum; ++i)
6125     {
6126       Arm_input_section<big_endian>* arm_input_section =
6127         arm_target->find_arm_input_section(this, i);
6128
6129       if (arm_input_section != NULL
6130           && arm_input_section->is_stub_table_owner()
6131           && !arm_input_section->stub_table()->empty())
6132         {
6133           // We cannot discard a section if it owns a stub table.
6134           Output_section* os = this->output_section(i);
6135           gold_assert(os != NULL);
6136
6137           relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6138           relinfo.reloc_shdr = NULL;
6139           relinfo.data_shndx = i;
6140           relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6141
6142           gold_assert((*pviews)[i].view != NULL);
6143
6144           // We are passed the output section view.  Adjust it to cover the
6145           // stub table only.
6146           Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6147           gold_assert((stub_table->address() >= (*pviews)[i].address)
6148                       && ((stub_table->address() + stub_table->data_size())
6149                           <= (*pviews)[i].address + (*pviews)[i].view_size));
6150
6151           off_t offset = stub_table->address() - (*pviews)[i].address;
6152           unsigned char* view = (*pviews)[i].view + offset;
6153           Arm_address address = stub_table->address();
6154           section_size_type view_size = stub_table->data_size();
6155  
6156           stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6157                                      view_size);
6158         }
6159
6160       // Apply Cortex A8 workaround if applicable.
6161       if (this->section_has_cortex_a8_workaround(i))
6162         {
6163           unsigned char* view = (*pviews)[i].view;
6164           Arm_address view_address = (*pviews)[i].address;
6165           section_size_type view_size = (*pviews)[i].view_size;
6166           Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6167
6168           // Adjust view to cover section.
6169           Output_section* os = this->output_section(i);
6170           gold_assert(os != NULL);
6171           Arm_address section_address =
6172             this->simple_input_section_output_address(i, os);
6173           uint64_t section_size = this->section_size(i);
6174
6175           gold_assert(section_address >= view_address
6176                       && ((section_address + section_size)
6177                           <= (view_address + view_size)));
6178
6179           unsigned char* section_view = view + (section_address - view_address);
6180
6181           // Apply the Cortex-A8 workaround to the output address range
6182           // corresponding to this input section.
6183           stub_table->apply_cortex_a8_workaround_to_address_range(
6184               arm_target,
6185               section_view,
6186               section_address,
6187               section_size);
6188         }
6189     }
6190 }
6191
6192 // Find the linked text section of an EXIDX section by looking the the first
6193 // relocation.  4.4.1 of the EHABI specifications says that an EXIDX section
6194 // must be linked to to its associated code section via the sh_link field of
6195 // its section header.  However, some tools are broken and the link is not
6196 // always set.  LD just drops such an EXIDX section silently, causing the
6197 // associated code not unwindabled.   Here we try a little bit harder to
6198 // discover the linked code section.
6199 //
6200 // PSHDR points to the section header of a relocation section of an EXIDX
6201 // section.  If we can find a linked text section, return true and
6202 // store the text section index in the location PSHNDX.  Otherwise
6203 // return false.
6204
6205 template<bool big_endian>
6206 bool
6207 Arm_relobj<big_endian>::find_linked_text_section(
6208     const unsigned char* pshdr,
6209     const unsigned char* psyms,
6210     unsigned int* pshndx)
6211 {
6212   elfcpp::Shdr<32, big_endian> shdr(pshdr);
6213   
6214   // If there is no relocation, we cannot find the linked text section.
6215   size_t reloc_size;
6216   if (shdr.get_sh_type() == elfcpp::SHT_REL)
6217       reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6218   else
6219       reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6220   size_t reloc_count = shdr.get_sh_size() / reloc_size;
6221  
6222   // Get the relocations.
6223   const unsigned char* prelocs =
6224       this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false); 
6225
6226   // Find the REL31 relocation for the first word of the first EXIDX entry.
6227   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6228     {
6229       Arm_address r_offset;
6230       typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6231       if (shdr.get_sh_type() == elfcpp::SHT_REL)
6232         {
6233           typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6234           r_info = reloc.get_r_info();
6235           r_offset = reloc.get_r_offset();
6236         }
6237       else
6238         {
6239           typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6240           r_info = reloc.get_r_info();
6241           r_offset = reloc.get_r_offset();
6242         }
6243
6244       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6245       if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6246         continue;
6247
6248       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6249       if (r_sym == 0
6250           || r_sym >= this->local_symbol_count()
6251           || r_offset != 0)
6252         continue;
6253
6254       // This is the relocation for the first word of the first EXIDX entry.
6255       // We expect to see a local section symbol.
6256       const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6257       elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6258       if (sym.get_st_type() == elfcpp::STT_SECTION)
6259         {
6260           *pshndx = this->adjust_shndx(sym.get_st_shndx());
6261           return true;
6262         }
6263       else
6264         return false;
6265     }
6266
6267   return false;
6268 }
6269
6270 // Make an EXIDX input section object for an EXIDX section whose index is
6271 // SHNDX.  SHDR is the section header of the EXIDX section and TEXT_SHNDX
6272 // is the section index of the linked text section.
6273
6274 template<bool big_endian>
6275 void
6276 Arm_relobj<big_endian>::make_exidx_input_section(
6277     unsigned int shndx,
6278     const elfcpp::Shdr<32, big_endian>& shdr,
6279     unsigned int text_shndx)
6280 {
6281   // Issue an error and ignore this EXIDX section if it points to a text
6282   // section already has an EXIDX section.
6283   if (this->exidx_section_map_[text_shndx] != NULL)
6284     {
6285       gold_error(_("EXIDX sections %u and %u both link to text section %u "
6286                    "in %s"),
6287                  shndx, this->exidx_section_map_[text_shndx]->shndx(),
6288                  text_shndx, this->name().c_str());
6289       return;
6290     }
6291
6292   // Create an Arm_exidx_input_section object for this EXIDX section.
6293   Arm_exidx_input_section* exidx_input_section =
6294     new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6295                                 shdr.get_sh_addralign());
6296   this->exidx_section_map_[text_shndx] = exidx_input_section;
6297
6298   // Also map the EXIDX section index to this.
6299   gold_assert(this->exidx_section_map_[shndx] == NULL);
6300   this->exidx_section_map_[shndx] = exidx_input_section;
6301 }
6302
6303 // Read the symbol information.
6304
6305 template<bool big_endian>
6306 void
6307 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6308 {
6309   // Call parent class to read symbol information.
6310   Sized_relobj<32, big_endian>::do_read_symbols(sd);
6311
6312   // Read processor-specific flags in ELF file header.
6313   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6314                                               elfcpp::Elf_sizes<32>::ehdr_size,
6315                                               true, false);
6316   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6317   this->processor_specific_flags_ = ehdr.get_e_flags();
6318
6319   // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6320   // sections.
6321   std::vector<unsigned int> deferred_exidx_sections;
6322   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6323   const unsigned char* pshdrs = sd->section_headers->data();
6324   const unsigned char *ps = pshdrs + shdr_size;
6325   for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6326     {
6327       elfcpp::Shdr<32, big_endian> shdr(ps);
6328       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6329         {
6330           gold_assert(this->attributes_section_data_ == NULL);
6331           section_offset_type section_offset = shdr.get_sh_offset();
6332           section_size_type section_size =
6333             convert_to_section_size_type(shdr.get_sh_size());
6334           File_view* view = this->get_lasting_view(section_offset,
6335                                                    section_size, true, false);
6336           this->attributes_section_data_ =
6337             new Attributes_section_data(view->data(), section_size);
6338         }
6339       else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6340         {
6341           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6342           if (text_shndx >= this->shnum())
6343             gold_error(_("EXIDX section %u linked to invalid section %u"),
6344                        i, text_shndx);
6345           else if (text_shndx == elfcpp::SHN_UNDEF)
6346             deferred_exidx_sections.push_back(i);
6347           else
6348             this->make_exidx_input_section(i, shdr, text_shndx);
6349         }
6350     }
6351
6352   // Some tools are broken and they do not set the link of EXIDX sections. 
6353   // We look at the first relocation to figure out the linked sections.
6354   if (!deferred_exidx_sections.empty())
6355     {
6356       // We need to go over the section headers again to find the mapping
6357       // from sections being relocated to their relocation sections.  This is
6358       // a bit inefficient as we could do that in the loop above.  However,
6359       // we do not expect any deferred EXIDX sections normally.  So we do not
6360       // want to slow down the most common path.
6361       typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6362       Reloc_map reloc_map;
6363       ps = pshdrs + shdr_size;
6364       for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6365         {
6366           elfcpp::Shdr<32, big_endian> shdr(ps);
6367           elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6368           if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6369             {
6370               unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6371               if (info_shndx >= this->shnum())
6372                 gold_error(_("relocation section %u has invalid info %u"),
6373                            i, info_shndx);
6374               Reloc_map::value_type value(info_shndx, i);
6375               std::pair<Reloc_map::iterator, bool> result =
6376                 reloc_map.insert(value);
6377               if (!result.second)
6378                 gold_error(_("section %u has multiple relocation sections "
6379                              "%u and %u"),
6380                            info_shndx, i, reloc_map[info_shndx]);
6381             }
6382         }
6383
6384       // Read the symbol table section header.
6385       const unsigned int symtab_shndx = this->symtab_shndx();
6386       elfcpp::Shdr<32, big_endian>
6387           symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6388       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6389
6390       // Read the local symbols.
6391       const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6392       const unsigned int loccount = this->local_symbol_count();
6393       gold_assert(loccount == symtabshdr.get_sh_info());
6394       off_t locsize = loccount * sym_size;
6395       const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6396                                                   locsize, true, true);
6397
6398       // Process the deferred EXIDX sections. 
6399       for(unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6400         {
6401           unsigned int shndx = deferred_exidx_sections[i];
6402           elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6403           unsigned int text_shndx;
6404           Reloc_map::const_iterator it = reloc_map.find(shndx);
6405           if (it != reloc_map.end()
6406               && find_linked_text_section(pshdrs + it->second * shdr_size,
6407                                           psyms, &text_shndx))
6408             this->make_exidx_input_section(shndx, shdr, text_shndx);
6409           else
6410             gold_error(_("EXIDX section %u has no linked text section."),
6411                        shndx);
6412         }
6413     }
6414 }
6415
6416 // Process relocations for garbage collection.  The ARM target uses .ARM.exidx
6417 // sections for unwinding.  These sections are referenced implicitly by 
6418 // text sections linked in the section headers.  If we ignore these implict
6419 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6420 // will be garbage-collected incorrectly.  Hence we override the same function
6421 // in the base class to handle these implicit references.
6422
6423 template<bool big_endian>
6424 void
6425 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6426                                              Layout* layout,
6427                                              Read_relocs_data* rd)
6428 {
6429   // First, call base class method to process relocations in this object.
6430   Sized_relobj<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6431
6432   // If --gc-sections is not specified, there is nothing more to do.
6433   // This happens when --icf is used but --gc-sections is not.
6434   if (!parameters->options().gc_sections())
6435     return;
6436   
6437   unsigned int shnum = this->shnum();
6438   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6439   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6440                                                shnum * shdr_size,
6441                                                true, true);
6442
6443   // Scan section headers for sections of type SHT_ARM_EXIDX.  Add references
6444   // to these from the linked text sections.
6445   const unsigned char* ps = pshdrs + shdr_size;
6446   for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6447     {
6448       elfcpp::Shdr<32, big_endian> shdr(ps);
6449       if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6450         {
6451           // Found an .ARM.exidx section, add it to the set of reachable
6452           // sections from its linked text section.
6453           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6454           symtab->gc()->add_reference(this, text_shndx, this, i);
6455         }
6456     }
6457 }
6458
6459 // Update output local symbol count.  Owing to EXIDX entry merging, some local
6460 // symbols  will be removed in output.  Adjust output local symbol count
6461 // accordingly.  We can only changed the static output local symbol count.  It
6462 // is too late to change the dynamic symbols.
6463
6464 template<bool big_endian>
6465 void
6466 Arm_relobj<big_endian>::update_output_local_symbol_count()
6467 {
6468   // Caller should check that this needs updating.  We want caller checking
6469   // because output_local_symbol_count_needs_update() is most likely inlined.
6470   gold_assert(this->output_local_symbol_count_needs_update_);
6471
6472   gold_assert(this->symtab_shndx() != -1U);
6473   if (this->symtab_shndx() == 0)
6474     {
6475       // This object has no symbols.  Weird but legal.
6476       return;
6477     }
6478
6479   // Read the symbol table section header.
6480   const unsigned int symtab_shndx = this->symtab_shndx();
6481   elfcpp::Shdr<32, big_endian>
6482     symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6483   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6484
6485   // Read the local symbols.
6486   const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6487   const unsigned int loccount = this->local_symbol_count();
6488   gold_assert(loccount == symtabshdr.get_sh_info());
6489   off_t locsize = loccount * sym_size;
6490   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6491                                               locsize, true, true);
6492
6493   // Loop over the local symbols.
6494
6495   typedef typename Sized_relobj<32, big_endian>::Output_sections
6496      Output_sections;
6497   const Output_sections& out_sections(this->output_sections());
6498   unsigned int shnum = this->shnum();
6499   unsigned int count = 0;
6500   // Skip the first, dummy, symbol.
6501   psyms += sym_size;
6502   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6503     {
6504       elfcpp::Sym<32, big_endian> sym(psyms);
6505
6506       Symbol_value<32>& lv((*this->local_values())[i]);
6507
6508       // This local symbol was already discarded by do_count_local_symbols.
6509       if (!lv.needs_output_symtab_entry())
6510         continue;
6511
6512       bool is_ordinary;
6513       unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6514                                                   &is_ordinary);
6515
6516       if (shndx < shnum)
6517         {
6518           Output_section* os = out_sections[shndx];
6519
6520           // This local symbol no longer has an output section.  Discard it.
6521           if (os == NULL)
6522             {
6523               lv.set_no_output_symtab_entry();
6524               continue;
6525             }
6526
6527           // Currently we only discard parts of EXIDX input sections.
6528           // We explicitly check for a merged EXIDX input section to avoid
6529           // calling Output_section_data::output_offset unless necessary.
6530           if ((this->get_output_section_offset(shndx) == invalid_address)
6531               && (this->exidx_input_section_by_shndx(shndx) != NULL))
6532             {
6533               section_offset_type output_offset =
6534                 os->output_offset(this, shndx, lv.input_value());
6535               if (output_offset == -1)
6536                 {
6537                   // This symbol is defined in a part of an EXIDX input section
6538                   // that is discarded due to entry merging.
6539                   lv.set_no_output_symtab_entry();
6540                   continue;
6541                 }       
6542             }
6543         }
6544
6545       ++count;
6546     }
6547
6548   this->set_output_local_symbol_count(count);
6549   this->output_local_symbol_count_needs_update_ = false;
6550 }
6551
6552 // Arm_dynobj methods.
6553
6554 // Read the symbol information.
6555
6556 template<bool big_endian>
6557 void
6558 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6559 {
6560   // Call parent class to read symbol information.
6561   Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6562
6563   // Read processor-specific flags in ELF file header.
6564   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6565                                               elfcpp::Elf_sizes<32>::ehdr_size,
6566                                               true, false);
6567   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6568   this->processor_specific_flags_ = ehdr.get_e_flags();
6569
6570   // Read the attributes section if there is one.
6571   // We read from the end because gas seems to put it near the end of
6572   // the section headers.
6573   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6574   const unsigned char *ps =
6575     sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6576   for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6577     {
6578       elfcpp::Shdr<32, big_endian> shdr(ps);
6579       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6580         {
6581           section_offset_type section_offset = shdr.get_sh_offset();
6582           section_size_type section_size =
6583             convert_to_section_size_type(shdr.get_sh_size());
6584           File_view* view = this->get_lasting_view(section_offset,
6585                                                    section_size, true, false);
6586           this->attributes_section_data_ =
6587             new Attributes_section_data(view->data(), section_size);
6588           break;
6589         }
6590     }
6591 }
6592
6593 // Stub_addend_reader methods.
6594
6595 // Read the addend of a REL relocation of type R_TYPE at VIEW.
6596
6597 template<bool big_endian>
6598 elfcpp::Elf_types<32>::Elf_Swxword
6599 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
6600     unsigned int r_type,
6601     const unsigned char* view,
6602     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
6603 {
6604   typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
6605   
6606   switch (r_type)
6607     {
6608     case elfcpp::R_ARM_CALL:
6609     case elfcpp::R_ARM_JUMP24:
6610     case elfcpp::R_ARM_PLT32:
6611       {
6612         typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
6613         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6614         Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
6615         return utils::sign_extend<26>(val << 2);
6616       }
6617
6618     case elfcpp::R_ARM_THM_CALL:
6619     case elfcpp::R_ARM_THM_JUMP24:
6620     case elfcpp::R_ARM_THM_XPC22:
6621       {
6622         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
6623         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6624         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
6625         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
6626         return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
6627       }
6628
6629     case elfcpp::R_ARM_THM_JUMP19:
6630       {
6631         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
6632         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6633         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
6634         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
6635         return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
6636       }
6637
6638     default:
6639       gold_unreachable();
6640     }
6641 }
6642
6643 // Arm_output_data_got methods.
6644
6645 // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
6646 // The first one is initialized to be 1, which is the module index for
6647 // the main executable and the second one 0.  A reloc of the type
6648 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
6649 // be applied by gold.  GSYM is a global symbol.
6650 //
6651 template<bool big_endian>
6652 void
6653 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
6654     unsigned int got_type,
6655     Symbol* gsym)
6656 {
6657   if (gsym->has_got_offset(got_type))
6658     return;
6659
6660   // We are doing a static link.  Just mark it as belong to module 1,
6661   // the executable.
6662   unsigned int got_offset = this->add_constant(1);
6663   gsym->set_got_offset(got_type, got_offset); 
6664   got_offset = this->add_constant(0);
6665   this->static_relocs_.push_back(Static_reloc(got_offset,
6666                                               elfcpp::R_ARM_TLS_DTPOFF32,
6667                                               gsym));
6668 }
6669
6670 // Same as the above but for a local symbol.
6671
6672 template<bool big_endian>
6673 void
6674 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
6675   unsigned int got_type,
6676   Sized_relobj<32, big_endian>* object,
6677   unsigned int index)
6678 {
6679   if (object->local_has_got_offset(index, got_type))
6680     return;
6681
6682   // We are doing a static link.  Just mark it as belong to module 1,
6683   // the executable.
6684   unsigned int got_offset = this->add_constant(1);
6685   object->set_local_got_offset(index, got_type, got_offset);
6686   got_offset = this->add_constant(0);
6687   this->static_relocs_.push_back(Static_reloc(got_offset, 
6688                                               elfcpp::R_ARM_TLS_DTPOFF32, 
6689                                               object, index));
6690 }
6691
6692 template<bool big_endian>
6693 void
6694 Arm_output_data_got<big_endian>::do_write(Output_file* of)
6695 {
6696   // Call parent to write out GOT.
6697   Output_data_got<32, big_endian>::do_write(of);
6698
6699   // We are done if there is no fix up.
6700   if (this->static_relocs_.empty())
6701     return;
6702
6703   gold_assert(parameters->doing_static_link());
6704
6705   const off_t offset = this->offset();
6706   const section_size_type oview_size =
6707     convert_to_section_size_type(this->data_size());
6708   unsigned char* const oview = of->get_output_view(offset, oview_size);
6709
6710   Output_segment* tls_segment = this->layout_->tls_segment();
6711   gold_assert(tls_segment != NULL);
6712   
6713   // The thread pointer $tp points to the TCB, which is followed by the
6714   // TLS.  So we need to adjust $tp relative addressing by this amount.
6715   Arm_address aligned_tcb_size =
6716     align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
6717
6718   for (size_t i = 0; i < this->static_relocs_.size(); ++i)
6719     {
6720       Static_reloc& reloc(this->static_relocs_[i]);
6721       
6722       Arm_address value;
6723       if (!reloc.symbol_is_global())
6724         {
6725           Sized_relobj<32, big_endian>* object = reloc.relobj();
6726           const Symbol_value<32>* psymval =
6727             reloc.relobj()->local_symbol(reloc.index());
6728
6729           // We are doing static linking.  Issue an error and skip this
6730           // relocation if the symbol is undefined or in a discarded_section.
6731           bool is_ordinary;
6732           unsigned int shndx = psymval->input_shndx(&is_ordinary);
6733           if ((shndx == elfcpp::SHN_UNDEF)
6734               || (is_ordinary
6735                   && shndx != elfcpp::SHN_UNDEF
6736                   && !object->is_section_included(shndx)
6737                   && !this->symbol_table_->is_section_folded(object, shndx)))
6738             {
6739               gold_error(_("undefined or discarded local symbol %u from "
6740                            " object %s in GOT"),
6741                          reloc.index(), reloc.relobj()->name().c_str());
6742               continue;
6743             }
6744           
6745           value = psymval->value(object, 0);
6746         }
6747       else
6748         {
6749           const Symbol* gsym = reloc.symbol();
6750           gold_assert(gsym != NULL);
6751           if (gsym->is_forwarder())
6752             gsym = this->symbol_table_->resolve_forwards(gsym);
6753
6754           // We are doing static linking.  Issue an error and skip this
6755           // relocation if the symbol is undefined or in a discarded_section
6756           // unless it is a weakly_undefined symbol.
6757           if ((gsym->is_defined_in_discarded_section()
6758                || gsym->is_undefined())
6759               && !gsym->is_weak_undefined())
6760             {
6761               gold_error(_("undefined or discarded symbol %s in GOT"),
6762                          gsym->name());
6763               continue;
6764             }
6765
6766           if (!gsym->is_weak_undefined())
6767             {
6768               const Sized_symbol<32>* sym =
6769                 static_cast<const Sized_symbol<32>*>(gsym);
6770               value = sym->value();
6771             }
6772           else
6773               value = 0;
6774         }
6775
6776       unsigned got_offset = reloc.got_offset();
6777       gold_assert(got_offset < oview_size);
6778
6779       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
6780       Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
6781       Valtype x;
6782       switch (reloc.r_type())
6783         {
6784         case elfcpp::R_ARM_TLS_DTPOFF32:
6785           x = value;
6786           break;
6787         case elfcpp::R_ARM_TLS_TPOFF32:
6788           x = value + aligned_tcb_size;
6789           break;
6790         default:
6791           gold_unreachable();
6792         }
6793       elfcpp::Swap<32, big_endian>::writeval(wv, x);
6794     }
6795
6796   of->write_output_view(offset, oview_size, oview);
6797 }
6798
6799 // A class to handle the PLT data.
6800
6801 template<bool big_endian>
6802 class Output_data_plt_arm : public Output_section_data
6803 {
6804  public:
6805   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
6806     Reloc_section;
6807
6808   Output_data_plt_arm(Layout*, Output_data_space*);
6809
6810   // Add an entry to the PLT.
6811   void
6812   add_entry(Symbol* gsym);
6813
6814   // Return the .rel.plt section data.
6815   const Reloc_section*
6816   rel_plt() const
6817   { return this->rel_; }
6818
6819  protected:
6820   void
6821   do_adjust_output_section(Output_section* os);
6822
6823   // Write to a map file.
6824   void
6825   do_print_to_mapfile(Mapfile* mapfile) const
6826   { mapfile->print_output_data(this, _("** PLT")); }
6827
6828  private:
6829   // Template for the first PLT entry.
6830   static const uint32_t first_plt_entry[5];
6831
6832   // Template for subsequent PLT entries. 
6833   static const uint32_t plt_entry[3];
6834
6835   // Set the final size.
6836   void
6837   set_final_data_size()
6838   {
6839     this->set_data_size(sizeof(first_plt_entry)
6840                         + this->count_ * sizeof(plt_entry));
6841   }
6842
6843   // Write out the PLT data.
6844   void
6845   do_write(Output_file*);
6846
6847   // The reloc section.
6848   Reloc_section* rel_;
6849   // The .got.plt section.
6850   Output_data_space* got_plt_;
6851   // The number of PLT entries.
6852   unsigned int count_;
6853 };
6854
6855 // Create the PLT section.  The ordinary .got section is an argument,
6856 // since we need to refer to the start.  We also create our own .got
6857 // section just for PLT entries.
6858
6859 template<bool big_endian>
6860 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
6861                                                      Output_data_space* got_plt)
6862   : Output_section_data(4), got_plt_(got_plt), count_(0)
6863 {
6864   this->rel_ = new Reloc_section(false);
6865   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
6866                                   elfcpp::SHF_ALLOC, this->rel_, true, false,
6867                                   false, false);
6868 }
6869
6870 template<bool big_endian>
6871 void
6872 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
6873 {
6874   os->set_entsize(0);
6875 }
6876
6877 // Add an entry to the PLT.
6878
6879 template<bool big_endian>
6880 void
6881 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
6882 {
6883   gold_assert(!gsym->has_plt_offset());
6884
6885   // Note that when setting the PLT offset we skip the initial
6886   // reserved PLT entry.
6887   gsym->set_plt_offset((this->count_) * sizeof(plt_entry)
6888                        + sizeof(first_plt_entry));
6889
6890   ++this->count_;
6891
6892   section_offset_type got_offset = this->got_plt_->current_data_size();
6893
6894   // Every PLT entry needs a GOT entry which points back to the PLT
6895   // entry (this will be changed by the dynamic linker, normally
6896   // lazily when the function is called).
6897   this->got_plt_->set_current_data_size(got_offset + 4);
6898
6899   // Every PLT entry needs a reloc.
6900   gsym->set_needs_dynsym_entry();
6901   this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
6902                          got_offset);
6903
6904   // Note that we don't need to save the symbol.  The contents of the
6905   // PLT are independent of which symbols are used.  The symbols only
6906   // appear in the relocations.
6907 }
6908
6909 // ARM PLTs.
6910 // FIXME:  This is not very flexible.  Right now this has only been tested
6911 // on armv5te.  If we are to support additional architecture features like
6912 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
6913
6914 // The first entry in the PLT.
6915 template<bool big_endian>
6916 const uint32_t Output_data_plt_arm<big_endian>::first_plt_entry[5] =
6917 {
6918   0xe52de004,   // str   lr, [sp, #-4]!
6919   0xe59fe004,   // ldr   lr, [pc, #4]
6920   0xe08fe00e,   // add   lr, pc, lr 
6921   0xe5bef008,   // ldr   pc, [lr, #8]!
6922   0x00000000,   // &GOT[0] - .
6923 };
6924
6925 // Subsequent entries in the PLT.
6926
6927 template<bool big_endian>
6928 const uint32_t Output_data_plt_arm<big_endian>::plt_entry[3] =
6929 {
6930   0xe28fc600,   // add   ip, pc, #0xNN00000
6931   0xe28cca00,   // add   ip, ip, #0xNN000
6932   0xe5bcf000,   // ldr   pc, [ip, #0xNNN]!
6933 };
6934
6935 // Write out the PLT.  This uses the hand-coded instructions above,
6936 // and adjusts them as needed.  This is all specified by the arm ELF
6937 // Processor Supplement.
6938
6939 template<bool big_endian>
6940 void
6941 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
6942 {
6943   const off_t offset = this->offset();
6944   const section_size_type oview_size =
6945     convert_to_section_size_type(this->data_size());
6946   unsigned char* const oview = of->get_output_view(offset, oview_size);
6947
6948   const off_t got_file_offset = this->got_plt_->offset();
6949   const section_size_type got_size =
6950     convert_to_section_size_type(this->got_plt_->data_size());
6951   unsigned char* const got_view = of->get_output_view(got_file_offset,
6952                                                       got_size);
6953   unsigned char* pov = oview;
6954
6955   Arm_address plt_address = this->address();
6956   Arm_address got_address = this->got_plt_->address();
6957
6958   // Write first PLT entry.  All but the last word are constants.
6959   const size_t num_first_plt_words = (sizeof(first_plt_entry)
6960                                       / sizeof(plt_entry[0]));
6961   for (size_t i = 0; i < num_first_plt_words - 1; i++)
6962     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
6963   // Last word in first PLT entry is &GOT[0] - .
6964   elfcpp::Swap<32, big_endian>::writeval(pov + 16,
6965                                          got_address - (plt_address + 16));
6966   pov += sizeof(first_plt_entry);
6967
6968   unsigned char* got_pov = got_view;
6969
6970   memset(got_pov, 0, 12);
6971   got_pov += 12;
6972
6973   const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
6974   unsigned int plt_offset = sizeof(first_plt_entry);
6975   unsigned int plt_rel_offset = 0;
6976   unsigned int got_offset = 12;
6977   const unsigned int count = this->count_;
6978   for (unsigned int i = 0;
6979        i < count;
6980        ++i,
6981          pov += sizeof(plt_entry),
6982          got_pov += 4,
6983          plt_offset += sizeof(plt_entry),
6984          plt_rel_offset += rel_size,
6985          got_offset += 4)
6986     {
6987       // Set and adjust the PLT entry itself.
6988       int32_t offset = ((got_address + got_offset)
6989                          - (plt_address + plt_offset + 8));
6990
6991       gold_assert(offset >= 0 && offset < 0x0fffffff);
6992       uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
6993       elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
6994       uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
6995       elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
6996       uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
6997       elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
6998
6999       // Set the entry in the GOT.
7000       elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7001     }
7002
7003   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7004   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7005
7006   of->write_output_view(offset, oview_size, oview);
7007   of->write_output_view(got_file_offset, got_size, got_view);
7008 }
7009
7010 // Create a PLT entry for a global symbol.
7011
7012 template<bool big_endian>
7013 void
7014 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7015                                        Symbol* gsym)
7016 {
7017   if (gsym->has_plt_offset())
7018     return;
7019
7020   if (this->plt_ == NULL)
7021     {
7022       // Create the GOT sections first.
7023       this->got_section(symtab, layout);
7024
7025       this->plt_ = new Output_data_plt_arm<big_endian>(layout, this->got_plt_);
7026       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7027                                       (elfcpp::SHF_ALLOC
7028                                        | elfcpp::SHF_EXECINSTR),
7029                                       this->plt_, false, false, false, false);
7030     }
7031   this->plt_->add_entry(gsym);
7032 }
7033
7034 // Get the section to use for TLS_DESC relocations.
7035
7036 template<bool big_endian>
7037 typename Target_arm<big_endian>::Reloc_section*
7038 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7039 {
7040   return this->plt_section()->rel_tls_desc(layout);
7041 }
7042
7043 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7044
7045 template<bool big_endian>
7046 void
7047 Target_arm<big_endian>::define_tls_base_symbol(
7048     Symbol_table* symtab,
7049     Layout* layout)
7050 {
7051   if (this->tls_base_symbol_defined_)
7052     return;
7053
7054   Output_segment* tls_segment = layout->tls_segment();
7055   if (tls_segment != NULL)
7056     {
7057       bool is_exec = parameters->options().output_is_executable();
7058       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7059                                        Symbol_table::PREDEFINED,
7060                                        tls_segment, 0, 0,
7061                                        elfcpp::STT_TLS,
7062                                        elfcpp::STB_LOCAL,
7063                                        elfcpp::STV_HIDDEN, 0,
7064                                        (is_exec
7065                                         ? Symbol::SEGMENT_END
7066                                         : Symbol::SEGMENT_START),
7067                                        true);
7068     }
7069   this->tls_base_symbol_defined_ = true;
7070 }
7071
7072 // Create a GOT entry for the TLS module index.
7073
7074 template<bool big_endian>
7075 unsigned int
7076 Target_arm<big_endian>::got_mod_index_entry(
7077     Symbol_table* symtab,
7078     Layout* layout,
7079     Sized_relobj<32, big_endian>* object)
7080 {
7081   if (this->got_mod_index_offset_ == -1U)
7082     {
7083       gold_assert(symtab != NULL && layout != NULL && object != NULL);
7084       Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7085       unsigned int got_offset;
7086       if (!parameters->doing_static_link())
7087         {
7088           got_offset = got->add_constant(0);
7089           Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7090           rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7091                              got_offset);
7092         }
7093       else
7094         {
7095           // We are doing a static link.  Just mark it as belong to module 1,
7096           // the executable.
7097           got_offset = got->add_constant(1);
7098         }
7099
7100       got->add_constant(0);
7101       this->got_mod_index_offset_ = got_offset;
7102     }
7103   return this->got_mod_index_offset_;
7104 }
7105
7106 // Optimize the TLS relocation type based on what we know about the
7107 // symbol.  IS_FINAL is true if the final address of this symbol is
7108 // known at link time.
7109
7110 template<bool big_endian>
7111 tls::Tls_optimization
7112 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7113 {
7114   // FIXME: Currently we do not do any TLS optimization.
7115   return tls::TLSOPT_NONE;
7116 }
7117
7118 // Report an unsupported relocation against a local symbol.
7119
7120 template<bool big_endian>
7121 void
7122 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7123     Sized_relobj<32, big_endian>* object,
7124     unsigned int r_type)
7125 {
7126   gold_error(_("%s: unsupported reloc %u against local symbol"),
7127              object->name().c_str(), r_type);
7128 }
7129
7130 // We are about to emit a dynamic relocation of type R_TYPE.  If the
7131 // dynamic linker does not support it, issue an error.  The GNU linker
7132 // only issues a non-PIC error for an allocated read-only section.
7133 // Here we know the section is allocated, but we don't know that it is
7134 // read-only.  But we check for all the relocation types which the
7135 // glibc dynamic linker supports, so it seems appropriate to issue an
7136 // error even if the section is not read-only.
7137
7138 template<bool big_endian>
7139 void
7140 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7141                                             unsigned int r_type)
7142 {
7143   switch (r_type)
7144     {
7145     // These are the relocation types supported by glibc for ARM.
7146     case elfcpp::R_ARM_RELATIVE:
7147     case elfcpp::R_ARM_COPY:
7148     case elfcpp::R_ARM_GLOB_DAT:
7149     case elfcpp::R_ARM_JUMP_SLOT:
7150     case elfcpp::R_ARM_ABS32:
7151     case elfcpp::R_ARM_ABS32_NOI:
7152     case elfcpp::R_ARM_PC24:
7153     // FIXME: The following 3 types are not supported by Android's dynamic
7154     // linker.
7155     case elfcpp::R_ARM_TLS_DTPMOD32:
7156     case elfcpp::R_ARM_TLS_DTPOFF32:
7157     case elfcpp::R_ARM_TLS_TPOFF32:
7158       return;
7159
7160     default:
7161       {
7162         // This prevents us from issuing more than one error per reloc
7163         // section.  But we can still wind up issuing more than one
7164         // error per object file.
7165         if (this->issued_non_pic_error_)
7166           return;
7167         const Arm_reloc_property* reloc_property =
7168           arm_reloc_property_table->get_reloc_property(r_type);
7169         gold_assert(reloc_property != NULL);
7170         object->error(_("requires unsupported dynamic reloc %s; "
7171                       "recompile with -fPIC"),
7172                       reloc_property->name().c_str());
7173         this->issued_non_pic_error_ = true;
7174         return;
7175       }
7176
7177     case elfcpp::R_ARM_NONE:
7178       gold_unreachable();
7179     }
7180 }
7181
7182 // Scan a relocation for a local symbol.
7183 // FIXME: This only handles a subset of relocation types used by Android
7184 // on ARM v5te devices.
7185
7186 template<bool big_endian>
7187 inline void
7188 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7189                                     Layout* layout,
7190                                     Target_arm* target,
7191                                     Sized_relobj<32, big_endian>* object,
7192                                     unsigned int data_shndx,
7193                                     Output_section* output_section,
7194                                     const elfcpp::Rel<32, big_endian>& reloc,
7195                                     unsigned int r_type,
7196                                     const elfcpp::Sym<32, big_endian>& lsym)
7197 {
7198   r_type = get_real_reloc_type(r_type);
7199   switch (r_type)
7200     {
7201     case elfcpp::R_ARM_NONE:
7202     case elfcpp::R_ARM_V4BX:
7203     case elfcpp::R_ARM_GNU_VTENTRY:
7204     case elfcpp::R_ARM_GNU_VTINHERIT:
7205       break;
7206
7207     case elfcpp::R_ARM_ABS32:
7208     case elfcpp::R_ARM_ABS32_NOI:
7209       // If building a shared library (or a position-independent
7210       // executable), we need to create a dynamic relocation for
7211       // this location. The relocation applied at link time will
7212       // apply the link-time value, so we flag the location with
7213       // an R_ARM_RELATIVE relocation so the dynamic loader can
7214       // relocate it easily.
7215       if (parameters->options().output_is_position_independent())
7216         {
7217           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7218           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7219           // If we are to add more other reloc types than R_ARM_ABS32,
7220           // we need to add check_non_pic(object, r_type) here.
7221           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7222                                       output_section, data_shndx,
7223                                       reloc.get_r_offset());
7224         }
7225       break;
7226
7227     case elfcpp::R_ARM_ABS16:
7228     case elfcpp::R_ARM_ABS12:
7229     case elfcpp::R_ARM_THM_ABS5:
7230     case elfcpp::R_ARM_ABS8:
7231     case elfcpp::R_ARM_BASE_ABS:
7232     case elfcpp::R_ARM_MOVW_ABS_NC:
7233     case elfcpp::R_ARM_MOVT_ABS:
7234     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7235     case elfcpp::R_ARM_THM_MOVT_ABS:
7236       // If building a shared library (or a position-independent
7237       // executable), we need to create a dynamic relocation for
7238       // this location. Because the addend needs to remain in the
7239       // data section, we need to be careful not to apply this
7240       // relocation statically.
7241       if (parameters->options().output_is_position_independent())
7242         {
7243           check_non_pic(object, r_type);
7244           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7245           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7246           if (lsym.get_st_type() != elfcpp::STT_SECTION)
7247             rel_dyn->add_local(object, r_sym, r_type, output_section,
7248                                data_shndx, reloc.get_r_offset());
7249           else
7250             {
7251               gold_assert(lsym.get_st_value() == 0);
7252               unsigned int shndx = lsym.get_st_shndx();
7253               bool is_ordinary;
7254               shndx = object->adjust_sym_shndx(r_sym, shndx,
7255                                                &is_ordinary);
7256               if (!is_ordinary)
7257                 object->error(_("section symbol %u has bad shndx %u"),
7258                               r_sym, shndx);
7259               else
7260                 rel_dyn->add_local_section(object, shndx,
7261                                            r_type, output_section,
7262                                            data_shndx, reloc.get_r_offset());
7263             }
7264         }
7265       break;
7266
7267     case elfcpp::R_ARM_PC24:
7268     case elfcpp::R_ARM_REL32:
7269     case elfcpp::R_ARM_LDR_PC_G0:
7270     case elfcpp::R_ARM_SBREL32:
7271     case elfcpp::R_ARM_THM_CALL:
7272     case elfcpp::R_ARM_THM_PC8:
7273     case elfcpp::R_ARM_BASE_PREL:
7274     case elfcpp::R_ARM_PLT32:
7275     case elfcpp::R_ARM_CALL:
7276     case elfcpp::R_ARM_JUMP24:
7277     case elfcpp::R_ARM_THM_JUMP24:
7278     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7279     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7280     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7281     case elfcpp::R_ARM_SBREL31:
7282     case elfcpp::R_ARM_PREL31:
7283     case elfcpp::R_ARM_MOVW_PREL_NC:
7284     case elfcpp::R_ARM_MOVT_PREL:
7285     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7286     case elfcpp::R_ARM_THM_MOVT_PREL:
7287     case elfcpp::R_ARM_THM_JUMP19:
7288     case elfcpp::R_ARM_THM_JUMP6:
7289     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7290     case elfcpp::R_ARM_THM_PC12:
7291     case elfcpp::R_ARM_REL32_NOI:
7292     case elfcpp::R_ARM_ALU_PC_G0_NC:
7293     case elfcpp::R_ARM_ALU_PC_G0:
7294     case elfcpp::R_ARM_ALU_PC_G1_NC:
7295     case elfcpp::R_ARM_ALU_PC_G1:
7296     case elfcpp::R_ARM_ALU_PC_G2:
7297     case elfcpp::R_ARM_LDR_PC_G1:
7298     case elfcpp::R_ARM_LDR_PC_G2:
7299     case elfcpp::R_ARM_LDRS_PC_G0:
7300     case elfcpp::R_ARM_LDRS_PC_G1:
7301     case elfcpp::R_ARM_LDRS_PC_G2:
7302     case elfcpp::R_ARM_LDC_PC_G0:
7303     case elfcpp::R_ARM_LDC_PC_G1:
7304     case elfcpp::R_ARM_LDC_PC_G2:
7305     case elfcpp::R_ARM_ALU_SB_G0_NC:
7306     case elfcpp::R_ARM_ALU_SB_G0:
7307     case elfcpp::R_ARM_ALU_SB_G1_NC:
7308     case elfcpp::R_ARM_ALU_SB_G1:
7309     case elfcpp::R_ARM_ALU_SB_G2:
7310     case elfcpp::R_ARM_LDR_SB_G0:
7311     case elfcpp::R_ARM_LDR_SB_G1:
7312     case elfcpp::R_ARM_LDR_SB_G2:
7313     case elfcpp::R_ARM_LDRS_SB_G0:
7314     case elfcpp::R_ARM_LDRS_SB_G1:
7315     case elfcpp::R_ARM_LDRS_SB_G2:
7316     case elfcpp::R_ARM_LDC_SB_G0:
7317     case elfcpp::R_ARM_LDC_SB_G1:
7318     case elfcpp::R_ARM_LDC_SB_G2:
7319     case elfcpp::R_ARM_MOVW_BREL_NC:
7320     case elfcpp::R_ARM_MOVT_BREL:
7321     case elfcpp::R_ARM_MOVW_BREL:
7322     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7323     case elfcpp::R_ARM_THM_MOVT_BREL:
7324     case elfcpp::R_ARM_THM_MOVW_BREL:
7325     case elfcpp::R_ARM_THM_JUMP11:
7326     case elfcpp::R_ARM_THM_JUMP8:
7327       // We don't need to do anything for a relative addressing relocation
7328       // against a local symbol if it does not reference the GOT.
7329       break;
7330
7331     case elfcpp::R_ARM_GOTOFF32:
7332     case elfcpp::R_ARM_GOTOFF12:
7333       // We need a GOT section:
7334       target->got_section(symtab, layout);
7335       break;
7336
7337     case elfcpp::R_ARM_GOT_BREL:
7338     case elfcpp::R_ARM_GOT_PREL:
7339       {
7340         // The symbol requires a GOT entry.
7341         Arm_output_data_got<big_endian>* got =
7342           target->got_section(symtab, layout);
7343         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7344         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
7345           {
7346             // If we are generating a shared object, we need to add a
7347             // dynamic RELATIVE relocation for this symbol's GOT entry.
7348             if (parameters->options().output_is_position_independent())
7349               {
7350                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7351                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7352                 rel_dyn->add_local_relative(
7353                     object, r_sym, elfcpp::R_ARM_RELATIVE, got,
7354                     object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
7355               }
7356           }
7357       }
7358       break;
7359
7360     case elfcpp::R_ARM_TARGET1:
7361     case elfcpp::R_ARM_TARGET2:
7362       // This should have been mapped to another type already.
7363       // Fall through.
7364     case elfcpp::R_ARM_COPY:
7365     case elfcpp::R_ARM_GLOB_DAT:
7366     case elfcpp::R_ARM_JUMP_SLOT:
7367     case elfcpp::R_ARM_RELATIVE:
7368       // These are relocations which should only be seen by the
7369       // dynamic linker, and should never be seen here.
7370       gold_error(_("%s: unexpected reloc %u in object file"),
7371                  object->name().c_str(), r_type);
7372       break;
7373
7374
7375       // These are initial TLS relocs, which are expected when
7376       // linking.
7377     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
7378     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
7379     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
7380     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
7381     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
7382       {
7383         bool output_is_shared = parameters->options().shared();
7384         const tls::Tls_optimization optimized_type
7385             = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
7386                                                          r_type);
7387         switch (r_type)
7388           {
7389           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
7390             if (optimized_type == tls::TLSOPT_NONE)
7391               {
7392                 // Create a pair of GOT entries for the module index and
7393                 // dtv-relative offset.
7394                 Arm_output_data_got<big_endian>* got
7395                     = target->got_section(symtab, layout);
7396                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7397                 unsigned int shndx = lsym.get_st_shndx();
7398                 bool is_ordinary;
7399                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
7400                 if (!is_ordinary)
7401                   {
7402                     object->error(_("local symbol %u has bad shndx %u"),
7403                                   r_sym, shndx);
7404                     break;
7405                   }
7406
7407                 if (!parameters->doing_static_link())
7408                   got->add_local_pair_with_rel(object, r_sym, shndx,
7409                                                GOT_TYPE_TLS_PAIR,
7410                                                target->rel_dyn_section(layout),
7411                                                elfcpp::R_ARM_TLS_DTPMOD32, 0);
7412                 else
7413                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
7414                                                       object, r_sym);
7415               }
7416             else
7417               // FIXME: TLS optimization not supported yet.
7418               gold_unreachable();
7419             break;
7420
7421           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
7422             if (optimized_type == tls::TLSOPT_NONE)
7423               {
7424                 // Create a GOT entry for the module index.
7425                 target->got_mod_index_entry(symtab, layout, object);
7426               }
7427             else
7428               // FIXME: TLS optimization not supported yet.
7429               gold_unreachable();
7430             break;
7431
7432           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
7433             break;
7434
7435           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
7436             layout->set_has_static_tls();
7437             if (optimized_type == tls::TLSOPT_NONE)
7438               {
7439                 // Create a GOT entry for the tp-relative offset.
7440                 Arm_output_data_got<big_endian>* got
7441                   = target->got_section(symtab, layout);
7442                 unsigned int r_sym =
7443                    elfcpp::elf_r_sym<32>(reloc.get_r_info());
7444                 if (!parameters->doing_static_link())
7445                     got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
7446                                             target->rel_dyn_section(layout),
7447                                             elfcpp::R_ARM_TLS_TPOFF32);
7448                 else if (!object->local_has_got_offset(r_sym,
7449                                                        GOT_TYPE_TLS_OFFSET))
7450                   {
7451                     got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
7452                     unsigned int got_offset =
7453                       object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
7454                     got->add_static_reloc(got_offset,
7455                                           elfcpp::R_ARM_TLS_TPOFF32, object,
7456                                           r_sym);
7457                   }
7458               }
7459             else
7460               // FIXME: TLS optimization not supported yet.
7461               gold_unreachable();
7462             break;
7463
7464           case elfcpp::R_ARM_TLS_LE32:          // Local-exec
7465             layout->set_has_static_tls();
7466             if (output_is_shared)
7467               {
7468                 // We need to create a dynamic relocation.
7469                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
7470                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7471                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7472                 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
7473                                    output_section, data_shndx,
7474                                    reloc.get_r_offset());
7475               }
7476             break;
7477
7478           default:
7479             gold_unreachable();
7480           }
7481       }
7482       break;
7483
7484     default:
7485       unsupported_reloc_local(object, r_type);
7486       break;
7487     }
7488 }
7489
7490 // Report an unsupported relocation against a global symbol.
7491
7492 template<bool big_endian>
7493 void
7494 Target_arm<big_endian>::Scan::unsupported_reloc_global(
7495     Sized_relobj<32, big_endian>* object,
7496     unsigned int r_type,
7497     Symbol* gsym)
7498 {
7499   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
7500              object->name().c_str(), r_type, gsym->demangled_name().c_str());
7501 }
7502
7503 // Scan a relocation for a global symbol.
7504
7505 template<bool big_endian>
7506 inline void
7507 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
7508                                      Layout* layout,
7509                                      Target_arm* target,
7510                                      Sized_relobj<32, big_endian>* object,
7511                                      unsigned int data_shndx,
7512                                      Output_section* output_section,
7513                                      const elfcpp::Rel<32, big_endian>& reloc,
7514                                      unsigned int r_type,
7515                                      Symbol* gsym)
7516 {
7517   // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
7518   // section.  We check here to avoid creating a dynamic reloc against
7519   // _GLOBAL_OFFSET_TABLE_.
7520   if (!target->has_got_section()
7521       && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
7522     target->got_section(symtab, layout);
7523
7524   r_type = get_real_reloc_type(r_type);
7525   switch (r_type)
7526     {
7527     case elfcpp::R_ARM_NONE:
7528     case elfcpp::R_ARM_V4BX:
7529     case elfcpp::R_ARM_GNU_VTENTRY:
7530     case elfcpp::R_ARM_GNU_VTINHERIT:
7531       break;
7532
7533     case elfcpp::R_ARM_ABS32:
7534     case elfcpp::R_ARM_ABS16:
7535     case elfcpp::R_ARM_ABS12:
7536     case elfcpp::R_ARM_THM_ABS5:
7537     case elfcpp::R_ARM_ABS8:
7538     case elfcpp::R_ARM_BASE_ABS:
7539     case elfcpp::R_ARM_MOVW_ABS_NC:
7540     case elfcpp::R_ARM_MOVT_ABS:
7541     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7542     case elfcpp::R_ARM_THM_MOVT_ABS:
7543     case elfcpp::R_ARM_ABS32_NOI:
7544       // Absolute addressing relocations.
7545       {
7546         // Make a PLT entry if necessary.
7547         if (this->symbol_needs_plt_entry(gsym))
7548           {
7549             target->make_plt_entry(symtab, layout, gsym);
7550             // Since this is not a PC-relative relocation, we may be
7551             // taking the address of a function. In that case we need to
7552             // set the entry in the dynamic symbol table to the address of
7553             // the PLT entry.
7554             if (gsym->is_from_dynobj() && !parameters->options().shared())
7555               gsym->set_needs_dynsym_value();
7556           }
7557         // Make a dynamic relocation if necessary.
7558         if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
7559           {
7560             if (gsym->may_need_copy_reloc())
7561               {
7562                 target->copy_reloc(symtab, layout, object,
7563                                    data_shndx, output_section, gsym, reloc);
7564               }
7565             else if ((r_type == elfcpp::R_ARM_ABS32
7566                       || r_type == elfcpp::R_ARM_ABS32_NOI)
7567                      && gsym->can_use_relative_reloc(false))
7568               {
7569                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7570                 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
7571                                              output_section, object,
7572                                              data_shndx, reloc.get_r_offset());
7573               }
7574             else
7575               {
7576                 check_non_pic(object, r_type);
7577                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7578                 rel_dyn->add_global(gsym, r_type, output_section, object,
7579                                     data_shndx, reloc.get_r_offset());
7580               }
7581           }
7582       }
7583       break;
7584
7585     case elfcpp::R_ARM_GOTOFF32:
7586     case elfcpp::R_ARM_GOTOFF12:
7587       // We need a GOT section.
7588       target->got_section(symtab, layout);
7589       break;
7590       
7591     case elfcpp::R_ARM_REL32:
7592     case elfcpp::R_ARM_LDR_PC_G0:
7593     case elfcpp::R_ARM_SBREL32:
7594     case elfcpp::R_ARM_THM_PC8:
7595     case elfcpp::R_ARM_BASE_PREL:
7596     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7597     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7598     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7599     case elfcpp::R_ARM_MOVW_PREL_NC:
7600     case elfcpp::R_ARM_MOVT_PREL:
7601     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7602     case elfcpp::R_ARM_THM_MOVT_PREL:
7603     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7604     case elfcpp::R_ARM_THM_PC12:
7605     case elfcpp::R_ARM_REL32_NOI:
7606     case elfcpp::R_ARM_ALU_PC_G0_NC:
7607     case elfcpp::R_ARM_ALU_PC_G0:
7608     case elfcpp::R_ARM_ALU_PC_G1_NC:
7609     case elfcpp::R_ARM_ALU_PC_G1:
7610     case elfcpp::R_ARM_ALU_PC_G2:
7611     case elfcpp::R_ARM_LDR_PC_G1:
7612     case elfcpp::R_ARM_LDR_PC_G2:
7613     case elfcpp::R_ARM_LDRS_PC_G0:
7614     case elfcpp::R_ARM_LDRS_PC_G1:
7615     case elfcpp::R_ARM_LDRS_PC_G2:
7616     case elfcpp::R_ARM_LDC_PC_G0:
7617     case elfcpp::R_ARM_LDC_PC_G1:
7618     case elfcpp::R_ARM_LDC_PC_G2:
7619     case elfcpp::R_ARM_ALU_SB_G0_NC:
7620     case elfcpp::R_ARM_ALU_SB_G0:
7621     case elfcpp::R_ARM_ALU_SB_G1_NC:
7622     case elfcpp::R_ARM_ALU_SB_G1:
7623     case elfcpp::R_ARM_ALU_SB_G2:
7624     case elfcpp::R_ARM_LDR_SB_G0:
7625     case elfcpp::R_ARM_LDR_SB_G1:
7626     case elfcpp::R_ARM_LDR_SB_G2:
7627     case elfcpp::R_ARM_LDRS_SB_G0:
7628     case elfcpp::R_ARM_LDRS_SB_G1:
7629     case elfcpp::R_ARM_LDRS_SB_G2:
7630     case elfcpp::R_ARM_LDC_SB_G0:
7631     case elfcpp::R_ARM_LDC_SB_G1:
7632     case elfcpp::R_ARM_LDC_SB_G2:
7633     case elfcpp::R_ARM_MOVW_BREL_NC:
7634     case elfcpp::R_ARM_MOVT_BREL:
7635     case elfcpp::R_ARM_MOVW_BREL:
7636     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7637     case elfcpp::R_ARM_THM_MOVT_BREL:
7638     case elfcpp::R_ARM_THM_MOVW_BREL:
7639       // Relative addressing relocations.
7640       {
7641         // Make a dynamic relocation if necessary.
7642         int flags = Symbol::NON_PIC_REF;
7643         if (gsym->needs_dynamic_reloc(flags))
7644           {
7645             if (target->may_need_copy_reloc(gsym))
7646               {
7647                 target->copy_reloc(symtab, layout, object,
7648                                    data_shndx, output_section, gsym, reloc);
7649               }
7650             else
7651               {
7652                 check_non_pic(object, r_type);
7653                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7654                 rel_dyn->add_global(gsym, r_type, output_section, object,
7655                                     data_shndx, reloc.get_r_offset());
7656               }
7657           }
7658       }
7659       break;
7660
7661     case elfcpp::R_ARM_PC24:
7662     case elfcpp::R_ARM_THM_CALL:
7663     case elfcpp::R_ARM_PLT32:
7664     case elfcpp::R_ARM_CALL:
7665     case elfcpp::R_ARM_JUMP24:
7666     case elfcpp::R_ARM_THM_JUMP24:
7667     case elfcpp::R_ARM_SBREL31:
7668     case elfcpp::R_ARM_PREL31:
7669     case elfcpp::R_ARM_THM_JUMP19:
7670     case elfcpp::R_ARM_THM_JUMP6:
7671     case elfcpp::R_ARM_THM_JUMP11:
7672     case elfcpp::R_ARM_THM_JUMP8:
7673       // All the relocation above are branches except for the PREL31 ones.
7674       // A PREL31 relocation can point to a personality function in a shared
7675       // library.  In that case we want to use a PLT because we want to
7676       // call the personality routine and the dyanmic linkers we care about
7677       // do not support dynamic PREL31 relocations. An REL31 relocation may
7678       // point to a function whose unwinding behaviour is being described but
7679       // we will not mistakenly generate a PLT for that because we should use
7680       // a local section symbol.
7681
7682       // If the symbol is fully resolved, this is just a relative
7683       // local reloc.  Otherwise we need a PLT entry.
7684       if (gsym->final_value_is_known())
7685         break;
7686       // If building a shared library, we can also skip the PLT entry
7687       // if the symbol is defined in the output file and is protected
7688       // or hidden.
7689       if (gsym->is_defined()
7690           && !gsym->is_from_dynobj()
7691           && !gsym->is_preemptible())
7692         break;
7693       target->make_plt_entry(symtab, layout, gsym);
7694       break;
7695
7696     case elfcpp::R_ARM_GOT_BREL:
7697     case elfcpp::R_ARM_GOT_ABS:
7698     case elfcpp::R_ARM_GOT_PREL:
7699       {
7700         // The symbol requires a GOT entry.
7701         Arm_output_data_got<big_endian>* got =
7702           target->got_section(symtab, layout);
7703         if (gsym->final_value_is_known())
7704           got->add_global(gsym, GOT_TYPE_STANDARD);
7705         else
7706           {
7707             // If this symbol is not fully resolved, we need to add a
7708             // GOT entry with a dynamic relocation.
7709             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7710             if (gsym->is_from_dynobj()
7711                 || gsym->is_undefined()
7712                 || gsym->is_preemptible())
7713               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
7714                                        rel_dyn, elfcpp::R_ARM_GLOB_DAT);
7715             else
7716               {
7717                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
7718                   rel_dyn->add_global_relative(
7719                       gsym, elfcpp::R_ARM_RELATIVE, got,
7720                       gsym->got_offset(GOT_TYPE_STANDARD));
7721               }
7722           }
7723       }
7724       break;
7725
7726     case elfcpp::R_ARM_TARGET1:
7727     case elfcpp::R_ARM_TARGET2:
7728       // These should have been mapped to other types already.
7729       // Fall through.
7730     case elfcpp::R_ARM_COPY:
7731     case elfcpp::R_ARM_GLOB_DAT:
7732     case elfcpp::R_ARM_JUMP_SLOT:
7733     case elfcpp::R_ARM_RELATIVE:
7734       // These are relocations which should only be seen by the
7735       // dynamic linker, and should never be seen here.
7736       gold_error(_("%s: unexpected reloc %u in object file"),
7737                  object->name().c_str(), r_type);
7738       break;
7739
7740       // These are initial tls relocs, which are expected when
7741       // linking.
7742     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
7743     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
7744     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
7745     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
7746     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
7747       {
7748         const bool is_final = gsym->final_value_is_known();
7749         const tls::Tls_optimization optimized_type
7750             = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
7751         switch (r_type)
7752           {
7753           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
7754             if (optimized_type == tls::TLSOPT_NONE)
7755               {
7756                 // Create a pair of GOT entries for the module index and
7757                 // dtv-relative offset.
7758                 Arm_output_data_got<big_endian>* got
7759                     = target->got_section(symtab, layout);
7760                 if (!parameters->doing_static_link())
7761                   got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
7762                                                 target->rel_dyn_section(layout),
7763                                                 elfcpp::R_ARM_TLS_DTPMOD32,
7764                                                 elfcpp::R_ARM_TLS_DTPOFF32);
7765                 else
7766                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
7767               }
7768             else
7769               // FIXME: TLS optimization not supported yet.
7770               gold_unreachable();
7771             break;
7772
7773           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
7774             if (optimized_type == tls::TLSOPT_NONE)
7775               {
7776                 // Create a GOT entry for the module index.
7777                 target->got_mod_index_entry(symtab, layout, object);
7778               }
7779             else
7780               // FIXME: TLS optimization not supported yet.
7781               gold_unreachable();
7782             break;
7783
7784           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
7785             break;
7786
7787           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
7788             layout->set_has_static_tls();
7789             if (optimized_type == tls::TLSOPT_NONE)
7790               {
7791                 // Create a GOT entry for the tp-relative offset.
7792                 Arm_output_data_got<big_endian>* got
7793                   = target->got_section(symtab, layout);
7794                 if (!parameters->doing_static_link())
7795                   got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
7796                                            target->rel_dyn_section(layout),
7797                                            elfcpp::R_ARM_TLS_TPOFF32);
7798                 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
7799                   {
7800                     got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
7801                     unsigned int got_offset =
7802                        gsym->got_offset(GOT_TYPE_TLS_OFFSET);
7803                     got->add_static_reloc(got_offset,
7804                                           elfcpp::R_ARM_TLS_TPOFF32, gsym);
7805                   }
7806               }
7807             else
7808               // FIXME: TLS optimization not supported yet.
7809               gold_unreachable();
7810             break;
7811
7812           case elfcpp::R_ARM_TLS_LE32:  // Local-exec
7813             layout->set_has_static_tls();
7814             if (parameters->options().shared())
7815               {
7816                 // We need to create a dynamic relocation.
7817                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7818                 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
7819                                     output_section, object,
7820                                     data_shndx, reloc.get_r_offset());
7821               }
7822             break;
7823
7824           default:
7825             gold_unreachable();
7826           }
7827       }
7828       break;
7829
7830     default:
7831       unsupported_reloc_global(object, r_type, gsym);
7832       break;
7833     }
7834 }
7835
7836 // Process relocations for gc.
7837
7838 template<bool big_endian>
7839 void
7840 Target_arm<big_endian>::gc_process_relocs(Symbol_table* symtab,
7841                                           Layout* layout,
7842                                           Sized_relobj<32, big_endian>* object,
7843                                           unsigned int data_shndx,
7844                                           unsigned int,
7845                                           const unsigned char* prelocs,
7846                                           size_t reloc_count,
7847                                           Output_section* output_section,
7848                                           bool needs_special_offset_handling,
7849                                           size_t local_symbol_count,
7850                                           const unsigned char* plocal_symbols)
7851 {
7852   typedef Target_arm<big_endian> Arm;
7853   typedef typename Target_arm<big_endian>::Scan Scan;
7854
7855   gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan>(
7856     symtab,
7857     layout,
7858     this,
7859     object,
7860     data_shndx,
7861     prelocs,
7862     reloc_count,
7863     output_section,
7864     needs_special_offset_handling,
7865     local_symbol_count,
7866     plocal_symbols);
7867 }
7868
7869 // Scan relocations for a section.
7870
7871 template<bool big_endian>
7872 void
7873 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
7874                                     Layout* layout,
7875                                     Sized_relobj<32, big_endian>* object,
7876                                     unsigned int data_shndx,
7877                                     unsigned int sh_type,
7878                                     const unsigned char* prelocs,
7879                                     size_t reloc_count,
7880                                     Output_section* output_section,
7881                                     bool needs_special_offset_handling,
7882                                     size_t local_symbol_count,
7883                                     const unsigned char* plocal_symbols)
7884 {
7885   typedef typename Target_arm<big_endian>::Scan Scan;
7886   if (sh_type == elfcpp::SHT_RELA)
7887     {
7888       gold_error(_("%s: unsupported RELA reloc section"),
7889                  object->name().c_str());
7890       return;
7891     }
7892
7893   gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
7894     symtab,
7895     layout,
7896     this,
7897     object,
7898     data_shndx,
7899     prelocs,
7900     reloc_count,
7901     output_section,
7902     needs_special_offset_handling,
7903     local_symbol_count,
7904     plocal_symbols);
7905 }
7906
7907 // Finalize the sections.
7908
7909 template<bool big_endian>
7910 void
7911 Target_arm<big_endian>::do_finalize_sections(
7912     Layout* layout,
7913     const Input_objects* input_objects,
7914     Symbol_table* symtab)
7915 {
7916   // Create an empty uninitialized attribute section if we still don't have it
7917   // at this moment.
7918   if (this->attributes_section_data_ == NULL)
7919     this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
7920
7921   // Merge processor-specific flags.
7922   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
7923        p != input_objects->relobj_end();
7924        ++p)
7925     {
7926       // If this input file is a binary file, it has no processor
7927       // specific flags and attributes section.
7928       Input_file::Format format = (*p)->input_file()->format();
7929       if (format != Input_file::FORMAT_ELF)
7930         {
7931           gold_assert(format == Input_file::FORMAT_BINARY);
7932           continue;
7933         }
7934
7935       Arm_relobj<big_endian>* arm_relobj =
7936         Arm_relobj<big_endian>::as_arm_relobj(*p);
7937       this->merge_processor_specific_flags(
7938           arm_relobj->name(),
7939           arm_relobj->processor_specific_flags());
7940       this->merge_object_attributes(arm_relobj->name().c_str(),
7941                                     arm_relobj->attributes_section_data());
7942
7943     } 
7944
7945   for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
7946        p != input_objects->dynobj_end();
7947        ++p)
7948     {
7949       Arm_dynobj<big_endian>* arm_dynobj =
7950         Arm_dynobj<big_endian>::as_arm_dynobj(*p);
7951       this->merge_processor_specific_flags(
7952           arm_dynobj->name(),
7953           arm_dynobj->processor_specific_flags());
7954       this->merge_object_attributes(arm_dynobj->name().c_str(),
7955                                     arm_dynobj->attributes_section_data());
7956     }
7957
7958   // Check BLX use.
7959   const Object_attribute* cpu_arch_attr =
7960     this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
7961   if (cpu_arch_attr->int_value() > elfcpp::TAG_CPU_ARCH_V4)
7962     this->set_may_use_blx(true);
7963  
7964   // Check if we need to use Cortex-A8 workaround.
7965   if (parameters->options().user_set_fix_cortex_a8())
7966     this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
7967   else
7968     {
7969       // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
7970       // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
7971       // profile.  
7972       const Object_attribute* cpu_arch_profile_attr =
7973         this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
7974       this->fix_cortex_a8_ =
7975         (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
7976          && (cpu_arch_profile_attr->int_value() == 'A'
7977              || cpu_arch_profile_attr->int_value() == 0));
7978     }
7979   
7980   // Check if we can use V4BX interworking.
7981   // The V4BX interworking stub contains BX instruction,
7982   // which is not specified for some profiles.
7983   if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
7984       && !this->may_use_blx())
7985     gold_error(_("unable to provide V4BX reloc interworking fix up; "
7986                  "the target profile does not support BX instruction"));
7987
7988   // Fill in some more dynamic tags.
7989   const Reloc_section* rel_plt = (this->plt_ == NULL
7990                                   ? NULL
7991                                   : this->plt_->rel_plt());
7992   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
7993                                   this->rel_dyn_, true, false);
7994
7995   // Emit any relocs we saved in an attempt to avoid generating COPY
7996   // relocs.
7997   if (this->copy_relocs_.any_saved_relocs())
7998     this->copy_relocs_.emit(this->rel_dyn_section(layout));
7999
8000   // Handle the .ARM.exidx section.
8001   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8002   if (exidx_section != NULL
8003       && exidx_section->type() == elfcpp::SHT_ARM_EXIDX
8004       && !parameters->options().relocatable())
8005     {
8006       // Create __exidx_start and __exdix_end symbols.
8007       symtab->define_in_output_data("__exidx_start", NULL,
8008                                     Symbol_table::PREDEFINED,
8009                                     exidx_section, 0, 0, elfcpp::STT_OBJECT,
8010                                     elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8011                                     false, true);
8012       symtab->define_in_output_data("__exidx_end", NULL,
8013                                     Symbol_table::PREDEFINED,
8014                                     exidx_section, 0, 0, elfcpp::STT_OBJECT,
8015                                     elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8016                                     true, true);
8017
8018       // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8019       // the .ARM.exidx section.
8020       if (!layout->script_options()->saw_phdrs_clause())
8021         {
8022           gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0, 0)
8023                       == NULL);
8024           Output_segment*  exidx_segment =
8025             layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8026           exidx_segment->add_output_section(exidx_section, elfcpp::PF_R,
8027                                             false);
8028         }
8029     }
8030
8031   // Create an .ARM.attributes section if there is not one already.
8032   Output_attributes_section_data* attributes_section =
8033     new Output_attributes_section_data(*this->attributes_section_data_);
8034   layout->add_output_section_data(".ARM.attributes",
8035                                   elfcpp::SHT_ARM_ATTRIBUTES, 0,
8036                                   attributes_section, false, false, false,
8037                                   false);
8038 }
8039
8040 // Return whether a direct absolute static relocation needs to be applied.
8041 // In cases where Scan::local() or Scan::global() has created
8042 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8043 // of the relocation is carried in the data, and we must not
8044 // apply the static relocation.
8045
8046 template<bool big_endian>
8047 inline bool
8048 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8049     const Sized_symbol<32>* gsym,
8050     int ref_flags,
8051     bool is_32bit,
8052     Output_section* output_section)
8053 {
8054   // If the output section is not allocated, then we didn't call
8055   // scan_relocs, we didn't create a dynamic reloc, and we must apply
8056   // the reloc here.
8057   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8058       return true;
8059
8060   // For local symbols, we will have created a non-RELATIVE dynamic
8061   // relocation only if (a) the output is position independent,
8062   // (b) the relocation is absolute (not pc- or segment-relative), and
8063   // (c) the relocation is not 32 bits wide.
8064   if (gsym == NULL)
8065     return !(parameters->options().output_is_position_independent()
8066              && (ref_flags & Symbol::ABSOLUTE_REF)
8067              && !is_32bit);
8068
8069   // For global symbols, we use the same helper routines used in the
8070   // scan pass.  If we did not create a dynamic relocation, or if we
8071   // created a RELATIVE dynamic relocation, we should apply the static
8072   // relocation.
8073   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8074   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8075                  && gsym->can_use_relative_reloc(ref_flags
8076                                                  & Symbol::FUNCTION_CALL);
8077   return !has_dyn || is_rel;
8078 }
8079
8080 // Perform a relocation.
8081
8082 template<bool big_endian>
8083 inline bool
8084 Target_arm<big_endian>::Relocate::relocate(
8085     const Relocate_info<32, big_endian>* relinfo,
8086     Target_arm* target,
8087     Output_section *output_section,
8088     size_t relnum,
8089     const elfcpp::Rel<32, big_endian>& rel,
8090     unsigned int r_type,
8091     const Sized_symbol<32>* gsym,
8092     const Symbol_value<32>* psymval,
8093     unsigned char* view,
8094     Arm_address address,
8095     section_size_type view_size)
8096 {
8097   typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8098
8099   r_type = get_real_reloc_type(r_type);
8100   const Arm_reloc_property* reloc_property =
8101     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8102   if (reloc_property == NULL)
8103     {
8104       std::string reloc_name =
8105         arm_reloc_property_table->reloc_name_in_error_message(r_type);
8106       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8107                              _("cannot relocate %s in object file"),
8108                              reloc_name.c_str());
8109       return true;
8110     }
8111
8112   const Arm_relobj<big_endian>* object =
8113     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8114
8115   // If the final branch target of a relocation is THUMB instruction, this
8116   // is 1.  Otherwise it is 0.
8117   Arm_address thumb_bit = 0;
8118   Symbol_value<32> symval;
8119   bool is_weakly_undefined_without_plt = false;
8120   if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8121     {
8122       if (gsym != NULL)
8123         {
8124           // This is a global symbol.  Determine if we use PLT and if the
8125           // final target is THUMB.
8126           if (gsym->use_plt_offset(reloc_is_non_pic(r_type)))
8127             {
8128               // This uses a PLT, change the symbol value.
8129               symval.set_output_value(target->plt_section()->address()
8130                                       + gsym->plt_offset());
8131               psymval = &symval;
8132             }
8133           else if (gsym->is_weak_undefined())
8134             {
8135               // This is a weakly undefined symbol and we do not use PLT
8136               // for this relocation.  A branch targeting this symbol will
8137               // be converted into an NOP.
8138               is_weakly_undefined_without_plt = true;
8139             }
8140           else
8141             {
8142               // Set thumb bit if symbol:
8143               // -Has type STT_ARM_TFUNC or
8144               // -Has type STT_FUNC, is defined and with LSB in value set.
8145               thumb_bit =
8146                 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8147                  || (gsym->type() == elfcpp::STT_FUNC
8148                      && !gsym->is_undefined()
8149                      && ((psymval->value(object, 0) & 1) != 0)))
8150                 ? 1
8151                 : 0);
8152             }
8153         }
8154       else
8155         {
8156           // This is a local symbol.  Determine if the final target is THUMB.
8157           // We saved this information when all the local symbols were read.
8158           elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8159           unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8160           thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8161         }
8162     }
8163   else
8164     {
8165       // This is a fake relocation synthesized for a stub.  It does not have
8166       // a real symbol.  We just look at the LSB of the symbol value to
8167       // determine if the target is THUMB or not.
8168       thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8169     }
8170
8171   // Strip LSB if this points to a THUMB target.
8172   if (thumb_bit != 0
8173       && reloc_property->uses_thumb_bit() 
8174       && ((psymval->value(object, 0) & 1) != 0))
8175     {
8176       Arm_address stripped_value =
8177         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8178       symval.set_output_value(stripped_value);
8179       psymval = &symval;
8180     } 
8181
8182   // Get the GOT offset if needed.
8183   // The GOT pointer points to the end of the GOT section.
8184   // We need to subtract the size of the GOT section to get
8185   // the actual offset to use in the relocation.
8186   bool have_got_offset = false;
8187   unsigned int got_offset = 0;
8188   switch (r_type)
8189     {
8190     case elfcpp::R_ARM_GOT_BREL:
8191     case elfcpp::R_ARM_GOT_PREL:
8192       if (gsym != NULL)
8193         {
8194           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8195           got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8196                         - target->got_size());
8197         }
8198       else
8199         {
8200           unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8201           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
8202           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8203                         - target->got_size());
8204         }
8205       have_got_offset = true;
8206       break;
8207
8208     default:
8209       break;
8210     }
8211
8212   // To look up relocation stubs, we need to pass the symbol table index of
8213   // a local symbol.
8214   unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8215
8216   // Get the addressing origin of the output segment defining the
8217   // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8218   Arm_address sym_origin = 0;
8219   if (reloc_property->uses_symbol_base())
8220     {
8221       if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8222         // R_ARM_BASE_ABS with the NULL symbol will give the
8223         // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8224         // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8225         sym_origin = target->got_plt_section()->address();
8226       else if (gsym == NULL)
8227         sym_origin = 0;
8228       else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8229         sym_origin = gsym->output_segment()->vaddr();
8230       else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
8231         sym_origin = gsym->output_data()->address();
8232
8233       // TODO: Assumes the segment base to be zero for the global symbols
8234       // till the proper support for the segment-base-relative addressing
8235       // will be implemented.  This is consistent with GNU ld.
8236     }
8237
8238   // For relative addressing relocation, find out the relative address base.
8239   Arm_address relative_address_base = 0;
8240   switch(reloc_property->relative_address_base())
8241     {
8242     case Arm_reloc_property::RAB_NONE:
8243     // Relocations with relative address bases RAB_TLS and RAB_tp are
8244     // handled by relocate_tls.  So we do not need to do anything here.
8245     case Arm_reloc_property::RAB_TLS:
8246     case Arm_reloc_property::RAB_tp:
8247       break;
8248     case Arm_reloc_property::RAB_B_S:
8249       relative_address_base = sym_origin;
8250       break;
8251     case Arm_reloc_property::RAB_GOT_ORG:
8252       relative_address_base = target->got_plt_section()->address();
8253       break;
8254     case Arm_reloc_property::RAB_P:
8255       relative_address_base = address;
8256       break;
8257     case Arm_reloc_property::RAB_Pa:
8258       relative_address_base = address & 0xfffffffcU;
8259       break;
8260     default:
8261       gold_unreachable(); 
8262     }
8263     
8264   typename Arm_relocate_functions::Status reloc_status =
8265         Arm_relocate_functions::STATUS_OKAY;
8266   bool check_overflow = reloc_property->checks_overflow();
8267   switch (r_type)
8268     {
8269     case elfcpp::R_ARM_NONE:
8270       break;
8271
8272     case elfcpp::R_ARM_ABS8:
8273       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8274                                     output_section))
8275         reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
8276       break;
8277
8278     case elfcpp::R_ARM_ABS12:
8279       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8280                                     output_section))
8281         reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
8282       break;
8283
8284     case elfcpp::R_ARM_ABS16:
8285       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8286                                     output_section))
8287         reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
8288       break;
8289
8290     case elfcpp::R_ARM_ABS32:
8291       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
8292                                     output_section))
8293         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8294                                                      thumb_bit);
8295       break;
8296
8297     case elfcpp::R_ARM_ABS32_NOI:
8298       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
8299                                     output_section))
8300         // No thumb bit for this relocation: (S + A)
8301         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8302                                                      0);
8303       break;
8304
8305     case elfcpp::R_ARM_MOVW_ABS_NC:
8306       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8307                                     output_section))
8308         reloc_status = Arm_relocate_functions::movw(view, object, psymval,
8309                                                     0, thumb_bit,
8310                                                     check_overflow);
8311       break;
8312
8313     case elfcpp::R_ARM_MOVT_ABS:
8314       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8315                                     output_section))
8316         reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
8317       break;
8318
8319     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8320       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8321                                     output_section))
8322         reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
8323                                                         0, thumb_bit, false);
8324       break;
8325
8326     case elfcpp::R_ARM_THM_MOVT_ABS:
8327       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8328                                     output_section))
8329         reloc_status = Arm_relocate_functions::thm_movt(view, object,
8330                                                         psymval, 0);
8331       break;
8332
8333     case elfcpp::R_ARM_MOVW_PREL_NC:
8334     case elfcpp::R_ARM_MOVW_BREL_NC:
8335     case elfcpp::R_ARM_MOVW_BREL:
8336       reloc_status =
8337         Arm_relocate_functions::movw(view, object, psymval,
8338                                      relative_address_base, thumb_bit,
8339                                      check_overflow);
8340       break;
8341
8342     case elfcpp::R_ARM_MOVT_PREL:
8343     case elfcpp::R_ARM_MOVT_BREL:
8344       reloc_status =
8345         Arm_relocate_functions::movt(view, object, psymval,
8346                                      relative_address_base);
8347       break;
8348
8349     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8350     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8351     case elfcpp::R_ARM_THM_MOVW_BREL:
8352       reloc_status =
8353         Arm_relocate_functions::thm_movw(view, object, psymval,
8354                                          relative_address_base,
8355                                          thumb_bit, check_overflow);
8356       break;
8357
8358     case elfcpp::R_ARM_THM_MOVT_PREL:
8359     case elfcpp::R_ARM_THM_MOVT_BREL:
8360       reloc_status =
8361         Arm_relocate_functions::thm_movt(view, object, psymval,
8362                                          relative_address_base);
8363       break;
8364         
8365     case elfcpp::R_ARM_REL32:
8366       reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
8367                                                    address, thumb_bit);
8368       break;
8369
8370     case elfcpp::R_ARM_THM_ABS5:
8371       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8372                                     output_section))
8373         reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
8374       break;
8375
8376     // Thumb long branches.
8377     case elfcpp::R_ARM_THM_CALL:
8378     case elfcpp::R_ARM_THM_XPC22:
8379     case elfcpp::R_ARM_THM_JUMP24:
8380       reloc_status =
8381         Arm_relocate_functions::thumb_branch_common(
8382             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
8383             thumb_bit, is_weakly_undefined_without_plt);
8384       break;
8385
8386     case elfcpp::R_ARM_GOTOFF32:
8387       {
8388         Arm_address got_origin;
8389         got_origin = target->got_plt_section()->address();
8390         reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
8391                                                      got_origin, thumb_bit);
8392       }
8393       break;
8394
8395     case elfcpp::R_ARM_BASE_PREL:
8396       gold_assert(gsym != NULL);
8397       reloc_status =
8398           Arm_relocate_functions::base_prel(view, sym_origin, address);
8399       break;
8400
8401     case elfcpp::R_ARM_BASE_ABS:
8402       {
8403         if (!should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8404                                       output_section))
8405           break;
8406
8407         reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
8408       }
8409       break;
8410
8411     case elfcpp::R_ARM_GOT_BREL:
8412       gold_assert(have_got_offset);
8413       reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
8414       break;
8415
8416     case elfcpp::R_ARM_GOT_PREL:
8417       gold_assert(have_got_offset);
8418       // Get the address origin for GOT PLT, which is allocated right
8419       // after the GOT section, to calculate an absolute address of
8420       // the symbol GOT entry (got_origin + got_offset).
8421       Arm_address got_origin;
8422       got_origin = target->got_plt_section()->address();
8423       reloc_status = Arm_relocate_functions::got_prel(view,
8424                                                       got_origin + got_offset,
8425                                                       address);
8426       break;
8427
8428     case elfcpp::R_ARM_PLT32:
8429     case elfcpp::R_ARM_CALL:
8430     case elfcpp::R_ARM_JUMP24:
8431     case elfcpp::R_ARM_XPC25:
8432       gold_assert(gsym == NULL
8433                   || gsym->has_plt_offset()
8434                   || gsym->final_value_is_known()
8435                   || (gsym->is_defined()
8436                       && !gsym->is_from_dynobj()
8437                       && !gsym->is_preemptible()));
8438       reloc_status =
8439         Arm_relocate_functions::arm_branch_common(
8440             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
8441             thumb_bit, is_weakly_undefined_without_plt);
8442       break;
8443
8444     case elfcpp::R_ARM_THM_JUMP19:
8445       reloc_status =
8446         Arm_relocate_functions::thm_jump19(view, object, psymval, address,
8447                                            thumb_bit);
8448       break;
8449
8450     case elfcpp::R_ARM_THM_JUMP6:
8451       reloc_status =
8452         Arm_relocate_functions::thm_jump6(view, object, psymval, address);
8453       break;
8454
8455     case elfcpp::R_ARM_THM_JUMP8:
8456       reloc_status =
8457         Arm_relocate_functions::thm_jump8(view, object, psymval, address);
8458       break;
8459
8460     case elfcpp::R_ARM_THM_JUMP11:
8461       reloc_status =
8462         Arm_relocate_functions::thm_jump11(view, object, psymval, address);
8463       break;
8464
8465     case elfcpp::R_ARM_PREL31:
8466       reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
8467                                                     address, thumb_bit);
8468       break;
8469
8470     case elfcpp::R_ARM_V4BX:
8471       if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
8472         {
8473           const bool is_v4bx_interworking =
8474               (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
8475           reloc_status =
8476             Arm_relocate_functions::v4bx(relinfo, view, object, address,
8477                                          is_v4bx_interworking);
8478         }
8479       break;
8480
8481     case elfcpp::R_ARM_THM_PC8:
8482       reloc_status =
8483         Arm_relocate_functions::thm_pc8(view, object, psymval, address);
8484       break;
8485
8486     case elfcpp::R_ARM_THM_PC12:
8487       reloc_status =
8488         Arm_relocate_functions::thm_pc12(view, object, psymval, address);
8489       break;
8490
8491     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8492       reloc_status =
8493         Arm_relocate_functions::thm_alu11(view, object, psymval, address,
8494                                           thumb_bit);
8495       break;
8496
8497     case elfcpp::R_ARM_ALU_PC_G0_NC:
8498     case elfcpp::R_ARM_ALU_PC_G0:
8499     case elfcpp::R_ARM_ALU_PC_G1_NC:
8500     case elfcpp::R_ARM_ALU_PC_G1:
8501     case elfcpp::R_ARM_ALU_PC_G2:
8502     case elfcpp::R_ARM_ALU_SB_G0_NC:
8503     case elfcpp::R_ARM_ALU_SB_G0:
8504     case elfcpp::R_ARM_ALU_SB_G1_NC:
8505     case elfcpp::R_ARM_ALU_SB_G1:
8506     case elfcpp::R_ARM_ALU_SB_G2:
8507       reloc_status =
8508         Arm_relocate_functions::arm_grp_alu(view, object, psymval,
8509                                             reloc_property->group_index(),
8510                                             relative_address_base,
8511                                             thumb_bit, check_overflow);
8512       break;
8513
8514     case elfcpp::R_ARM_LDR_PC_G0:
8515     case elfcpp::R_ARM_LDR_PC_G1:
8516     case elfcpp::R_ARM_LDR_PC_G2:
8517     case elfcpp::R_ARM_LDR_SB_G0:
8518     case elfcpp::R_ARM_LDR_SB_G1:
8519     case elfcpp::R_ARM_LDR_SB_G2:
8520       reloc_status =
8521           Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
8522                                               reloc_property->group_index(),
8523                                               relative_address_base);
8524       break;
8525
8526     case elfcpp::R_ARM_LDRS_PC_G0:
8527     case elfcpp::R_ARM_LDRS_PC_G1:
8528     case elfcpp::R_ARM_LDRS_PC_G2:
8529     case elfcpp::R_ARM_LDRS_SB_G0:
8530     case elfcpp::R_ARM_LDRS_SB_G1:
8531     case elfcpp::R_ARM_LDRS_SB_G2:
8532       reloc_status =
8533           Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
8534                                                reloc_property->group_index(),
8535                                                relative_address_base);
8536       break;
8537
8538     case elfcpp::R_ARM_LDC_PC_G0:
8539     case elfcpp::R_ARM_LDC_PC_G1:
8540     case elfcpp::R_ARM_LDC_PC_G2:
8541     case elfcpp::R_ARM_LDC_SB_G0:
8542     case elfcpp::R_ARM_LDC_SB_G1:
8543     case elfcpp::R_ARM_LDC_SB_G2:
8544       reloc_status =
8545           Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
8546                                               reloc_property->group_index(),
8547                                               relative_address_base);
8548       break;
8549
8550       // These are initial tls relocs, which are expected when
8551       // linking.
8552     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8553     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8554     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8555     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8556     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8557       reloc_status =
8558         this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
8559                            view, address, view_size);
8560       break;
8561
8562     default:
8563       gold_unreachable();
8564     }
8565
8566   // Report any errors.
8567   switch (reloc_status)
8568     {
8569     case Arm_relocate_functions::STATUS_OKAY:
8570       break;
8571     case Arm_relocate_functions::STATUS_OVERFLOW:
8572       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8573                              _("relocation overflow in relocation %u"),
8574                              r_type);
8575       break;
8576     case Arm_relocate_functions::STATUS_BAD_RELOC:
8577       gold_error_at_location(
8578         relinfo,
8579         relnum,
8580         rel.get_r_offset(),
8581         _("unexpected opcode while processing relocation %u"),
8582         r_type);
8583       break;
8584     default:
8585       gold_unreachable();
8586     }
8587
8588   return true;
8589 }
8590
8591 // Perform a TLS relocation.
8592
8593 template<bool big_endian>
8594 inline typename Arm_relocate_functions<big_endian>::Status
8595 Target_arm<big_endian>::Relocate::relocate_tls(
8596     const Relocate_info<32, big_endian>* relinfo,
8597     Target_arm<big_endian>* target,
8598     size_t relnum,
8599     const elfcpp::Rel<32, big_endian>& rel,
8600     unsigned int r_type,
8601     const Sized_symbol<32>* gsym,
8602     const Symbol_value<32>* psymval,
8603     unsigned char* view,
8604     elfcpp::Elf_types<32>::Elf_Addr address,
8605     section_size_type /*view_size*/ )
8606 {
8607   typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
8608   typedef Relocate_functions<32, big_endian> RelocFuncs;
8609   Output_segment* tls_segment = relinfo->layout->tls_segment();
8610
8611   const Sized_relobj<32, big_endian>* object = relinfo->object;
8612
8613   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
8614
8615   const bool is_final = (gsym == NULL
8616                          ? !parameters->options().shared()
8617                          : gsym->final_value_is_known());
8618   const tls::Tls_optimization optimized_type
8619       = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8620   switch (r_type)
8621     {
8622     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8623         {
8624           unsigned int got_type = GOT_TYPE_TLS_PAIR;
8625           unsigned int got_offset;
8626           if (gsym != NULL)
8627             {
8628               gold_assert(gsym->has_got_offset(got_type));
8629               got_offset = gsym->got_offset(got_type) - target->got_size();
8630             }
8631           else
8632             {
8633               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8634               gold_assert(object->local_has_got_offset(r_sym, got_type));
8635               got_offset = (object->local_got_offset(r_sym, got_type)
8636                             - target->got_size());
8637             }
8638           if (optimized_type == tls::TLSOPT_NONE)
8639             {
8640               Arm_address got_entry =
8641                 target->got_plt_section()->address() + got_offset;
8642               
8643               // Relocate the field with the PC relative offset of the pair of
8644               // GOT entries.
8645               RelocFuncs::pcrel32(view, got_entry, address);
8646               return ArmRelocFuncs::STATUS_OKAY;
8647             }
8648         }
8649       break;
8650
8651     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8652       if (optimized_type == tls::TLSOPT_NONE)
8653         {
8654           // Relocate the field with the offset of the GOT entry for
8655           // the module index.
8656           unsigned int got_offset;
8657           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
8658                         - target->got_size());
8659           Arm_address got_entry =
8660             target->got_plt_section()->address() + got_offset;
8661
8662           // Relocate the field with the PC relative offset of the pair of
8663           // GOT entries.
8664           RelocFuncs::pcrel32(view, got_entry, address);
8665           return ArmRelocFuncs::STATUS_OKAY;
8666         }
8667       break;
8668
8669     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8670       RelocFuncs::rel32(view, value);
8671       return ArmRelocFuncs::STATUS_OKAY;
8672
8673     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8674       if (optimized_type == tls::TLSOPT_NONE)
8675         {
8676           // Relocate the field with the offset of the GOT entry for
8677           // the tp-relative offset of the symbol.
8678           unsigned int got_type = GOT_TYPE_TLS_OFFSET;
8679           unsigned int got_offset;
8680           if (gsym != NULL)
8681             {
8682               gold_assert(gsym->has_got_offset(got_type));
8683               got_offset = gsym->got_offset(got_type);
8684             }
8685           else
8686             {
8687               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8688               gold_assert(object->local_has_got_offset(r_sym, got_type));
8689               got_offset = object->local_got_offset(r_sym, got_type);
8690             }
8691
8692           // All GOT offsets are relative to the end of the GOT.
8693           got_offset -= target->got_size();
8694
8695           Arm_address got_entry =
8696             target->got_plt_section()->address() + got_offset;
8697
8698           // Relocate the field with the PC relative offset of the GOT entry.
8699           RelocFuncs::pcrel32(view, got_entry, address);
8700           return ArmRelocFuncs::STATUS_OKAY;
8701         }
8702       break;
8703
8704     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8705       // If we're creating a shared library, a dynamic relocation will
8706       // have been created for this location, so do not apply it now.
8707       if (!parameters->options().shared())
8708         {
8709           gold_assert(tls_segment != NULL);
8710
8711           // $tp points to the TCB, which is followed by the TLS, so we
8712           // need to add TCB size to the offset.
8713           Arm_address aligned_tcb_size =
8714             align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
8715           RelocFuncs::rel32(view, value + aligned_tcb_size);
8716
8717         }
8718       return ArmRelocFuncs::STATUS_OKAY;
8719     
8720     default:
8721       gold_unreachable();
8722     }
8723
8724   gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8725                          _("unsupported reloc %u"),
8726                          r_type);
8727   return ArmRelocFuncs::STATUS_BAD_RELOC;
8728 }
8729
8730 // Relocate section data.
8731
8732 template<bool big_endian>
8733 void
8734 Target_arm<big_endian>::relocate_section(
8735     const Relocate_info<32, big_endian>* relinfo,
8736     unsigned int sh_type,
8737     const unsigned char* prelocs,
8738     size_t reloc_count,
8739     Output_section* output_section,
8740     bool needs_special_offset_handling,
8741     unsigned char* view,
8742     Arm_address address,
8743     section_size_type view_size,
8744     const Reloc_symbol_changes* reloc_symbol_changes)
8745 {
8746   typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
8747   gold_assert(sh_type == elfcpp::SHT_REL);
8748
8749   // See if we are relocating a relaxed input section.  If so, the view
8750   // covers the whole output section and we need to adjust accordingly.
8751   if (needs_special_offset_handling)
8752     {
8753       const Output_relaxed_input_section* poris =
8754         output_section->find_relaxed_input_section(relinfo->object,
8755                                                    relinfo->data_shndx);
8756       if (poris != NULL)
8757         {
8758           Arm_address section_address = poris->address();
8759           section_size_type section_size = poris->data_size();
8760
8761           gold_assert((section_address >= address)
8762                       && ((section_address + section_size)
8763                           <= (address + view_size)));
8764
8765           off_t offset = section_address - address;
8766           view += offset;
8767           address += offset;
8768           view_size = section_size;
8769         }
8770     }
8771
8772   gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
8773                          Arm_relocate>(
8774     relinfo,
8775     this,
8776     prelocs,
8777     reloc_count,
8778     output_section,
8779     needs_special_offset_handling,
8780     view,
8781     address,
8782     view_size,
8783     reloc_symbol_changes);
8784 }
8785
8786 // Return the size of a relocation while scanning during a relocatable
8787 // link.
8788
8789 template<bool big_endian>
8790 unsigned int
8791 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
8792     unsigned int r_type,
8793     Relobj* object)
8794 {
8795   r_type = get_real_reloc_type(r_type);
8796   const Arm_reloc_property* arp =
8797       arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8798   if (arp != NULL)
8799     return arp->size();
8800   else
8801     {
8802       std::string reloc_name =
8803         arm_reloc_property_table->reloc_name_in_error_message(r_type);
8804       gold_error(_("%s: unexpected %s in object file"),
8805                  object->name().c_str(), reloc_name.c_str());
8806       return 0;
8807     }
8808 }
8809
8810 // Scan the relocs during a relocatable link.
8811
8812 template<bool big_endian>
8813 void
8814 Target_arm<big_endian>::scan_relocatable_relocs(
8815     Symbol_table* symtab,
8816     Layout* layout,
8817     Sized_relobj<32, big_endian>* object,
8818     unsigned int data_shndx,
8819     unsigned int sh_type,
8820     const unsigned char* prelocs,
8821     size_t reloc_count,
8822     Output_section* output_section,
8823     bool needs_special_offset_handling,
8824     size_t local_symbol_count,
8825     const unsigned char* plocal_symbols,
8826     Relocatable_relocs* rr)
8827 {
8828   gold_assert(sh_type == elfcpp::SHT_REL);
8829
8830   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
8831     Relocatable_size_for_reloc> Scan_relocatable_relocs;
8832
8833   gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
8834       Scan_relocatable_relocs>(
8835     symtab,
8836     layout,
8837     object,
8838     data_shndx,
8839     prelocs,
8840     reloc_count,
8841     output_section,
8842     needs_special_offset_handling,
8843     local_symbol_count,
8844     plocal_symbols,
8845     rr);
8846 }
8847
8848 // Relocate a section during a relocatable link.
8849
8850 template<bool big_endian>
8851 void
8852 Target_arm<big_endian>::relocate_for_relocatable(
8853     const Relocate_info<32, big_endian>* relinfo,
8854     unsigned int sh_type,
8855     const unsigned char* prelocs,
8856     size_t reloc_count,
8857     Output_section* output_section,
8858     off_t offset_in_output_section,
8859     const Relocatable_relocs* rr,
8860     unsigned char* view,
8861     Arm_address view_address,
8862     section_size_type view_size,
8863     unsigned char* reloc_view,
8864     section_size_type reloc_view_size)
8865 {
8866   gold_assert(sh_type == elfcpp::SHT_REL);
8867
8868   gold::relocate_for_relocatable<32, big_endian, elfcpp::SHT_REL>(
8869     relinfo,
8870     prelocs,
8871     reloc_count,
8872     output_section,
8873     offset_in_output_section,
8874     rr,
8875     view,
8876     view_address,
8877     view_size,
8878     reloc_view,
8879     reloc_view_size);
8880 }
8881
8882 // Return the value to use for a dynamic symbol which requires special
8883 // treatment.  This is how we support equality comparisons of function
8884 // pointers across shared library boundaries, as described in the
8885 // processor specific ABI supplement.
8886
8887 template<bool big_endian>
8888 uint64_t
8889 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
8890 {
8891   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
8892   return this->plt_section()->address() + gsym->plt_offset();
8893 }
8894
8895 // Map platform-specific relocs to real relocs
8896 //
8897 template<bool big_endian>
8898 unsigned int
8899 Target_arm<big_endian>::get_real_reloc_type (unsigned int r_type)
8900 {
8901   switch (r_type)
8902     {
8903     case elfcpp::R_ARM_TARGET1:
8904       // This is either R_ARM_ABS32 or R_ARM_REL32;
8905       return elfcpp::R_ARM_ABS32;
8906
8907     case elfcpp::R_ARM_TARGET2:
8908       // This can be any reloc type but ususally is R_ARM_GOT_PREL
8909       return elfcpp::R_ARM_GOT_PREL;
8910
8911     default:
8912       return r_type;
8913     }
8914 }
8915
8916 // Whether if two EABI versions V1 and V2 are compatible.
8917
8918 template<bool big_endian>
8919 bool
8920 Target_arm<big_endian>::are_eabi_versions_compatible(
8921     elfcpp::Elf_Word v1,
8922     elfcpp::Elf_Word v2)
8923 {
8924   // v4 and v5 are the same spec before and after it was released,
8925   // so allow mixing them.
8926   if ((v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
8927       || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
8928     return true;
8929
8930   return v1 == v2;
8931 }
8932
8933 // Combine FLAGS from an input object called NAME and the processor-specific
8934 // flags in the ELF header of the output.  Much of this is adapted from the
8935 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
8936 // in bfd/elf32-arm.c.
8937
8938 template<bool big_endian>
8939 void
8940 Target_arm<big_endian>::merge_processor_specific_flags(
8941     const std::string& name,
8942     elfcpp::Elf_Word flags)
8943 {
8944   if (this->are_processor_specific_flags_set())
8945     {
8946       elfcpp::Elf_Word out_flags = this->processor_specific_flags();
8947
8948       // Nothing to merge if flags equal to those in output.
8949       if (flags == out_flags)
8950         return;
8951
8952       // Complain about various flag mismatches.
8953       elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
8954       elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
8955       if (!this->are_eabi_versions_compatible(version1, version2))
8956         gold_error(_("Source object %s has EABI version %d but output has "
8957                      "EABI version %d."),
8958                    name.c_str(),
8959                    (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
8960                    (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
8961     }
8962   else
8963     {
8964       // If the input is the default architecture and had the default
8965       // flags then do not bother setting the flags for the output
8966       // architecture, instead allow future merges to do this.  If no
8967       // future merges ever set these flags then they will retain their
8968       // uninitialised values, which surprise surprise, correspond
8969       // to the default values.
8970       if (flags == 0)
8971         return;
8972
8973       // This is the first time, just copy the flags.
8974       // We only copy the EABI version for now.
8975       this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
8976     }
8977 }
8978
8979 // Adjust ELF file header.
8980 template<bool big_endian>
8981 void
8982 Target_arm<big_endian>::do_adjust_elf_header(
8983     unsigned char* view,
8984     int len) const
8985 {
8986   gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
8987
8988   elfcpp::Ehdr<32, big_endian> ehdr(view);
8989   unsigned char e_ident[elfcpp::EI_NIDENT];
8990   memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
8991
8992   if (elfcpp::arm_eabi_version(this->processor_specific_flags())
8993       == elfcpp::EF_ARM_EABI_UNKNOWN)
8994     e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
8995   else
8996     e_ident[elfcpp::EI_OSABI] = 0;
8997   e_ident[elfcpp::EI_ABIVERSION] = 0;
8998
8999   // FIXME: Do EF_ARM_BE8 adjustment.
9000
9001   elfcpp::Ehdr_write<32, big_endian> oehdr(view);
9002   oehdr.put_e_ident(e_ident);
9003 }
9004
9005 // do_make_elf_object to override the same function in the base class.
9006 // We need to use a target-specific sub-class of Sized_relobj<32, big_endian>
9007 // to store ARM specific information.  Hence we need to have our own
9008 // ELF object creation.
9009
9010 template<bool big_endian>
9011 Object*
9012 Target_arm<big_endian>::do_make_elf_object(
9013     const std::string& name,
9014     Input_file* input_file,
9015     off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
9016 {
9017   int et = ehdr.get_e_type();
9018   if (et == elfcpp::ET_REL)
9019     {
9020       Arm_relobj<big_endian>* obj =
9021         new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
9022       obj->setup();
9023       return obj;
9024     }
9025   else if (et == elfcpp::ET_DYN)
9026     {
9027       Sized_dynobj<32, big_endian>* obj =
9028         new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
9029       obj->setup();
9030       return obj;
9031     }
9032   else
9033     {
9034       gold_error(_("%s: unsupported ELF file type %d"),
9035                  name.c_str(), et);
9036       return NULL;
9037     }
9038 }
9039
9040 // Read the architecture from the Tag_also_compatible_with attribute, if any.
9041 // Returns -1 if no architecture could be read.
9042 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
9043
9044 template<bool big_endian>
9045 int
9046 Target_arm<big_endian>::get_secondary_compatible_arch(
9047     const Attributes_section_data* pasd)
9048 {
9049   const Object_attribute *known_attributes =
9050     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
9051
9052   // Note: the tag and its argument below are uleb128 values, though
9053   // currently-defined values fit in one byte for each.
9054   const std::string& sv =
9055     known_attributes[elfcpp::Tag_also_compatible_with].string_value();
9056   if (sv.size() == 2
9057       && sv.data()[0] == elfcpp::Tag_CPU_arch
9058       && (sv.data()[1] & 128) != 128)
9059    return sv.data()[1];
9060
9061   // This tag is "safely ignorable", so don't complain if it looks funny.
9062   return -1;
9063 }
9064
9065 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
9066 // The tag is removed if ARCH is -1.
9067 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
9068
9069 template<bool big_endian>
9070 void
9071 Target_arm<big_endian>::set_secondary_compatible_arch(
9072     Attributes_section_data* pasd,
9073     int arch)
9074 {
9075   Object_attribute *known_attributes =
9076     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
9077
9078   if (arch == -1)
9079     {
9080       known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
9081       return;
9082     }
9083
9084   // Note: the tag and its argument below are uleb128 values, though
9085   // currently-defined values fit in one byte for each.
9086   char sv[3];
9087   sv[0] = elfcpp::Tag_CPU_arch;
9088   gold_assert(arch != 0);
9089   sv[1] = arch;
9090   sv[2] = '\0';
9091
9092   known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
9093 }
9094
9095 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
9096 // into account.
9097 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
9098
9099 template<bool big_endian>
9100 int
9101 Target_arm<big_endian>::tag_cpu_arch_combine(
9102     const char* name,
9103     int oldtag,
9104     int* secondary_compat_out,
9105     int newtag,
9106     int secondary_compat)
9107 {
9108 #define T(X) elfcpp::TAG_CPU_ARCH_##X
9109   static const int v6t2[] =
9110     {
9111       T(V6T2),   // PRE_V4.
9112       T(V6T2),   // V4.
9113       T(V6T2),   // V4T.
9114       T(V6T2),   // V5T.
9115       T(V6T2),   // V5TE.
9116       T(V6T2),   // V5TEJ.
9117       T(V6T2),   // V6.
9118       T(V7),     // V6KZ.
9119       T(V6T2)    // V6T2.
9120     };
9121   static const int v6k[] =
9122     {
9123       T(V6K),    // PRE_V4.
9124       T(V6K),    // V4.
9125       T(V6K),    // V4T.
9126       T(V6K),    // V5T.
9127       T(V6K),    // V5TE.
9128       T(V6K),    // V5TEJ.
9129       T(V6K),    // V6.
9130       T(V6KZ),   // V6KZ.
9131       T(V7),     // V6T2.
9132       T(V6K)     // V6K.
9133     };
9134   static const int v7[] =
9135     {
9136       T(V7),     // PRE_V4.
9137       T(V7),     // V4.
9138       T(V7),     // V4T.
9139       T(V7),     // V5T.
9140       T(V7),     // V5TE.
9141       T(V7),     // V5TEJ.
9142       T(V7),     // V6.
9143       T(V7),     // V6KZ.
9144       T(V7),     // V6T2.
9145       T(V7),     // V6K.
9146       T(V7)      // V7.
9147     };
9148   static const int v6_m[] =
9149     {
9150       -1,        // PRE_V4.
9151       -1,        // V4.
9152       T(V6K),    // V4T.
9153       T(V6K),    // V5T.
9154       T(V6K),    // V5TE.
9155       T(V6K),    // V5TEJ.
9156       T(V6K),    // V6.
9157       T(V6KZ),   // V6KZ.
9158       T(V7),     // V6T2.
9159       T(V6K),    // V6K.
9160       T(V7),     // V7.
9161       T(V6_M)    // V6_M.
9162     };
9163   static const int v6s_m[] =
9164     {
9165       -1,        // PRE_V4.
9166       -1,        // V4.
9167       T(V6K),    // V4T.
9168       T(V6K),    // V5T.
9169       T(V6K),    // V5TE.
9170       T(V6K),    // V5TEJ.
9171       T(V6K),    // V6.
9172       T(V6KZ),   // V6KZ.
9173       T(V7),     // V6T2.
9174       T(V6K),    // V6K.
9175       T(V7),     // V7.
9176       T(V6S_M),  // V6_M.
9177       T(V6S_M)   // V6S_M.
9178     };
9179   static const int v7e_m[] =
9180     {
9181       -1,       // PRE_V4.
9182       -1,       // V4.
9183       T(V7E_M), // V4T.
9184       T(V7E_M), // V5T.
9185       T(V7E_M), // V5TE.
9186       T(V7E_M), // V5TEJ.
9187       T(V7E_M), // V6.
9188       T(V7E_M), // V6KZ.
9189       T(V7E_M), // V6T2.
9190       T(V7E_M), // V6K.
9191       T(V7E_M), // V7.
9192       T(V7E_M), // V6_M.
9193       T(V7E_M), // V6S_M.
9194       T(V7E_M)  // V7E_M.
9195     };
9196   static const int v4t_plus_v6_m[] =
9197     {
9198       -1,               // PRE_V4.
9199       -1,               // V4.
9200       T(V4T),           // V4T.
9201       T(V5T),           // V5T.
9202       T(V5TE),          // V5TE.
9203       T(V5TEJ),         // V5TEJ.
9204       T(V6),            // V6.
9205       T(V6KZ),          // V6KZ.
9206       T(V6T2),          // V6T2.
9207       T(V6K),           // V6K.
9208       T(V7),            // V7.
9209       T(V6_M),          // V6_M.
9210       T(V6S_M),         // V6S_M.
9211       T(V7E_M),         // V7E_M.
9212       T(V4T_PLUS_V6_M)  // V4T plus V6_M.
9213     };
9214   static const int *comb[] =
9215     {
9216       v6t2,
9217       v6k,
9218       v7,
9219       v6_m,
9220       v6s_m,
9221       v7e_m,
9222       // Pseudo-architecture.
9223       v4t_plus_v6_m
9224     };
9225
9226   // Check we've not got a higher architecture than we know about.
9227
9228   if (oldtag >= elfcpp::MAX_TAG_CPU_ARCH || newtag >= elfcpp::MAX_TAG_CPU_ARCH)
9229     {
9230       gold_error(_("%s: unknown CPU architecture"), name);
9231       return -1;
9232     }
9233
9234   // Override old tag if we have a Tag_also_compatible_with on the output.
9235
9236   if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
9237       || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
9238     oldtag = T(V4T_PLUS_V6_M);
9239
9240   // And override the new tag if we have a Tag_also_compatible_with on the
9241   // input.
9242
9243   if ((newtag == T(V6_M) && secondary_compat == T(V4T))
9244       || (newtag == T(V4T) && secondary_compat == T(V6_M)))
9245     newtag = T(V4T_PLUS_V6_M);
9246
9247   // Architectures before V6KZ add features monotonically.
9248   int tagh = std::max(oldtag, newtag);
9249   if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
9250     return tagh;
9251
9252   int tagl = std::min(oldtag, newtag);
9253   int result = comb[tagh - T(V6T2)][tagl];
9254
9255   // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
9256   // as the canonical version.
9257   if (result == T(V4T_PLUS_V6_M))
9258     {
9259       result = T(V4T);
9260       *secondary_compat_out = T(V6_M);
9261     }
9262   else
9263     *secondary_compat_out = -1;
9264
9265   if (result == -1)
9266     {
9267       gold_error(_("%s: conflicting CPU architectures %d/%d"),
9268                  name, oldtag, newtag);
9269       return -1;
9270     }
9271
9272   return result;
9273 #undef T
9274 }
9275
9276 // Helper to print AEABI enum tag value.
9277
9278 template<bool big_endian>
9279 std::string
9280 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
9281 {
9282   static const char *aeabi_enum_names[] =
9283     { "", "variable-size", "32-bit", "" };
9284   const size_t aeabi_enum_names_size =
9285     sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
9286
9287   if (value < aeabi_enum_names_size)
9288     return std::string(aeabi_enum_names[value]);
9289   else
9290     {
9291       char buffer[100];
9292       sprintf(buffer, "<unknown value %u>", value);
9293       return std::string(buffer);
9294     }
9295 }
9296
9297 // Return the string value to store in TAG_CPU_name.
9298
9299 template<bool big_endian>
9300 std::string
9301 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
9302 {
9303   static const char *name_table[] = {
9304     // These aren't real CPU names, but we can't guess
9305     // that from the architecture version alone.
9306    "Pre v4",
9307    "ARM v4",
9308    "ARM v4T",
9309    "ARM v5T",
9310    "ARM v5TE",
9311    "ARM v5TEJ",
9312    "ARM v6",
9313    "ARM v6KZ",
9314    "ARM v6T2",
9315    "ARM v6K",
9316    "ARM v7",
9317    "ARM v6-M",
9318    "ARM v6S-M",
9319    "ARM v7E-M"
9320  };
9321  const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
9322
9323   if (value < name_table_size)
9324     return std::string(name_table[value]);
9325   else
9326     {
9327       char buffer[100];
9328       sprintf(buffer, "<unknown CPU value %u>", value);
9329       return std::string(buffer);
9330     } 
9331 }
9332
9333 // Merge object attributes from input file called NAME with those of the
9334 // output.  The input object attributes are in the object pointed by PASD.
9335
9336 template<bool big_endian>
9337 void
9338 Target_arm<big_endian>::merge_object_attributes(
9339     const char* name,
9340     const Attributes_section_data* pasd)
9341 {
9342   // Return if there is no attributes section data.
9343   if (pasd == NULL)
9344     return;
9345
9346   // If output has no object attributes, just copy.
9347   if (this->attributes_section_data_ == NULL)
9348     {
9349       this->attributes_section_data_ = new Attributes_section_data(*pasd);
9350       return;
9351     }
9352
9353   const int vendor = Object_attribute::OBJ_ATTR_PROC;
9354   const Object_attribute* in_attr = pasd->known_attributes(vendor);
9355   Object_attribute* out_attr =
9356     this->attributes_section_data_->known_attributes(vendor);
9357
9358   // This needs to happen before Tag_ABI_FP_number_model is merged.  */
9359   if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
9360       != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
9361     {
9362       // Ignore mismatches if the object doesn't use floating point.  */
9363       if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
9364         out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
9365             in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
9366       else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0)
9367         gold_error(_("%s uses VFP register arguments, output does not"),
9368                    name);
9369     }
9370
9371   for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
9372     {
9373       // Merge this attribute with existing attributes.
9374       switch (i)
9375         {
9376         case elfcpp::Tag_CPU_raw_name:
9377         case elfcpp::Tag_CPU_name:
9378           // These are merged after Tag_CPU_arch.
9379           break;
9380
9381         case elfcpp::Tag_ABI_optimization_goals:
9382         case elfcpp::Tag_ABI_FP_optimization_goals:
9383           // Use the first value seen.
9384           break;
9385
9386         case elfcpp::Tag_CPU_arch:
9387           {
9388             unsigned int saved_out_attr = out_attr->int_value();
9389             // Merge Tag_CPU_arch and Tag_also_compatible_with.
9390             int secondary_compat =
9391               this->get_secondary_compatible_arch(pasd);
9392             int secondary_compat_out =
9393               this->get_secondary_compatible_arch(
9394                   this->attributes_section_data_);
9395             out_attr[i].set_int_value(
9396                 tag_cpu_arch_combine(name, out_attr[i].int_value(),
9397                                      &secondary_compat_out,
9398                                      in_attr[i].int_value(),
9399                                      secondary_compat));
9400             this->set_secondary_compatible_arch(this->attributes_section_data_,
9401                                                 secondary_compat_out);
9402
9403             // Merge Tag_CPU_name and Tag_CPU_raw_name.
9404             if (out_attr[i].int_value() == saved_out_attr)
9405               ; // Leave the names alone.
9406             else if (out_attr[i].int_value() == in_attr[i].int_value())
9407               {
9408                 // The output architecture has been changed to match the
9409                 // input architecture.  Use the input names.
9410                 out_attr[elfcpp::Tag_CPU_name].set_string_value(
9411                     in_attr[elfcpp::Tag_CPU_name].string_value());
9412                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
9413                     in_attr[elfcpp::Tag_CPU_raw_name].string_value());
9414               }
9415             else
9416               {
9417                 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
9418                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
9419               }
9420
9421             // If we still don't have a value for Tag_CPU_name,
9422             // make one up now.  Tag_CPU_raw_name remains blank.
9423             if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
9424               {
9425                 const std::string cpu_name =
9426                   this->tag_cpu_name_value(out_attr[i].int_value());
9427                 // FIXME:  If we see an unknown CPU, this will be set
9428                 // to "<unknown CPU n>", where n is the attribute value.
9429                 // This is different from BFD, which leaves the name alone.
9430                 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
9431               }
9432           }
9433           break;
9434
9435         case elfcpp::Tag_ARM_ISA_use:
9436         case elfcpp::Tag_THUMB_ISA_use:
9437         case elfcpp::Tag_WMMX_arch:
9438         case elfcpp::Tag_Advanced_SIMD_arch:
9439           // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
9440         case elfcpp::Tag_ABI_FP_rounding:
9441         case elfcpp::Tag_ABI_FP_exceptions:
9442         case elfcpp::Tag_ABI_FP_user_exceptions:
9443         case elfcpp::Tag_ABI_FP_number_model:
9444         case elfcpp::Tag_VFP_HP_extension:
9445         case elfcpp::Tag_CPU_unaligned_access:
9446         case elfcpp::Tag_T2EE_use:
9447         case elfcpp::Tag_Virtualization_use:
9448         case elfcpp::Tag_MPextension_use:
9449           // Use the largest value specified.
9450           if (in_attr[i].int_value() > out_attr[i].int_value())
9451             out_attr[i].set_int_value(in_attr[i].int_value());
9452           break;
9453
9454         case elfcpp::Tag_ABI_align8_preserved:
9455         case elfcpp::Tag_ABI_PCS_RO_data:
9456           // Use the smallest value specified.
9457           if (in_attr[i].int_value() < out_attr[i].int_value())
9458             out_attr[i].set_int_value(in_attr[i].int_value());
9459           break;
9460
9461         case elfcpp::Tag_ABI_align8_needed:
9462           if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
9463               && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
9464                   || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
9465                       == 0)))
9466             {
9467               // This error message should be enabled once all non-conformant
9468               // binaries in the toolchain have had the attributes set
9469               // properly.
9470               // gold_error(_("output 8-byte data alignment conflicts with %s"),
9471               //            name);
9472             }
9473           // Fall through.
9474         case elfcpp::Tag_ABI_FP_denormal:
9475         case elfcpp::Tag_ABI_PCS_GOT_use:
9476           {
9477             // These tags have 0 = don't care, 1 = strong requirement,
9478             // 2 = weak requirement.
9479             static const int order_021[3] = {0, 2, 1};
9480
9481             // Use the "greatest" from the sequence 0, 2, 1, or the largest
9482             // value if greater than 2 (for future-proofing).
9483             if ((in_attr[i].int_value() > 2
9484                  && in_attr[i].int_value() > out_attr[i].int_value())
9485                 || (in_attr[i].int_value() <= 2
9486                     && out_attr[i].int_value() <= 2
9487                     && (order_021[in_attr[i].int_value()]
9488                         > order_021[out_attr[i].int_value()])))
9489               out_attr[i].set_int_value(in_attr[i].int_value());
9490           }
9491           break;
9492
9493         case elfcpp::Tag_CPU_arch_profile:
9494           if (out_attr[i].int_value() != in_attr[i].int_value())
9495             {
9496               // 0 will merge with anything.
9497               // 'A' and 'S' merge to 'A'.
9498               // 'R' and 'S' merge to 'R'.
9499               // 'M' and 'A|R|S' is an error.
9500               if (out_attr[i].int_value() == 0
9501                   || (out_attr[i].int_value() == 'S'
9502                       && (in_attr[i].int_value() == 'A'
9503                           || in_attr[i].int_value() == 'R')))
9504                 out_attr[i].set_int_value(in_attr[i].int_value());
9505               else if (in_attr[i].int_value() == 0
9506                        || (in_attr[i].int_value() == 'S'
9507                            && (out_attr[i].int_value() == 'A'
9508                                || out_attr[i].int_value() == 'R')))
9509                 ; // Do nothing.
9510               else
9511                 {
9512                   gold_error
9513                     (_("conflicting architecture profiles %c/%c"),
9514                      in_attr[i].int_value() ? in_attr[i].int_value() : '0',
9515                      out_attr[i].int_value() ? out_attr[i].int_value() : '0');
9516                 }
9517             }
9518           break;
9519         case elfcpp::Tag_VFP_arch:
9520             {
9521               static const struct
9522               {
9523                   int ver;
9524                   int regs;
9525               } vfp_versions[7] =
9526                 {
9527                   {0, 0},
9528                   {1, 16},
9529                   {2, 16},
9530                   {3, 32},
9531                   {3, 16},
9532                   {4, 32},
9533                   {4, 16}
9534                 };
9535
9536               // Values greater than 6 aren't defined, so just pick the
9537               // biggest.
9538               if (in_attr[i].int_value() > 6
9539                   && in_attr[i].int_value() > out_attr[i].int_value())
9540                 {
9541                   *out_attr = *in_attr;
9542                   break;
9543                 }
9544               // The output uses the superset of input features
9545               // (ISA version) and registers.
9546               int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
9547                                  vfp_versions[out_attr[i].int_value()].ver);
9548               int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
9549                                   vfp_versions[out_attr[i].int_value()].regs);
9550               // This assumes all possible supersets are also a valid
9551               // options.
9552               int newval;
9553               for (newval = 6; newval > 0; newval--)
9554                 {
9555                   if (regs == vfp_versions[newval].regs
9556                       && ver == vfp_versions[newval].ver)
9557                     break;
9558                 }
9559               out_attr[i].set_int_value(newval);
9560             }
9561           break;
9562         case elfcpp::Tag_PCS_config:
9563           if (out_attr[i].int_value() == 0)
9564             out_attr[i].set_int_value(in_attr[i].int_value());
9565           else if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
9566             {
9567               // It's sometimes ok to mix different configs, so this is only
9568               // a warning.
9569               gold_warning(_("%s: conflicting platform configuration"), name);
9570             }
9571           break;
9572         case elfcpp::Tag_ABI_PCS_R9_use:
9573           if (in_attr[i].int_value() != out_attr[i].int_value()
9574               && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
9575               && in_attr[i].int_value() != elfcpp::AEABI_R9_unused)
9576             {
9577               gold_error(_("%s: conflicting use of R9"), name);
9578             }
9579           if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
9580             out_attr[i].set_int_value(in_attr[i].int_value());
9581           break;
9582         case elfcpp::Tag_ABI_PCS_RW_data:
9583           if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
9584               && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
9585                   != elfcpp::AEABI_R9_SB)
9586               && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
9587                   != elfcpp::AEABI_R9_unused))
9588             {
9589               gold_error(_("%s: SB relative addressing conflicts with use "
9590                            "of R9"),
9591                          name);
9592             }
9593           // Use the smallest value specified.
9594           if (in_attr[i].int_value() < out_attr[i].int_value())
9595             out_attr[i].set_int_value(in_attr[i].int_value());
9596           break;
9597         case elfcpp::Tag_ABI_PCS_wchar_t:
9598           // FIXME: Make it possible to turn off this warning.
9599           if (out_attr[i].int_value()
9600               && in_attr[i].int_value()
9601               && out_attr[i].int_value() != in_attr[i].int_value())
9602             {
9603               gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
9604                              "use %u-byte wchar_t; use of wchar_t values "
9605                              "across objects may fail"),
9606                            name, in_attr[i].int_value(),
9607                            out_attr[i].int_value());
9608             }
9609           else if (in_attr[i].int_value() && !out_attr[i].int_value())
9610             out_attr[i].set_int_value(in_attr[i].int_value());
9611           break;
9612         case elfcpp::Tag_ABI_enum_size:
9613           if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
9614             {
9615               if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
9616                   || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
9617                 {
9618                   // The existing object is compatible with anything.
9619                   // Use whatever requirements the new object has.
9620                   out_attr[i].set_int_value(in_attr[i].int_value());
9621                 }
9622               // FIXME: Make it possible to turn off this warning.
9623               else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
9624                        && out_attr[i].int_value() != in_attr[i].int_value())
9625                 {
9626                   unsigned int in_value = in_attr[i].int_value();
9627                   unsigned int out_value = out_attr[i].int_value();
9628                   gold_warning(_("%s uses %s enums yet the output is to use "
9629                                  "%s enums; use of enum values across objects "
9630                                  "may fail"),
9631                                name,
9632                                this->aeabi_enum_name(in_value).c_str(),
9633                                this->aeabi_enum_name(out_value).c_str());
9634                 }
9635             }
9636           break;
9637         case elfcpp::Tag_ABI_VFP_args:
9638           // Aready done.
9639           break;
9640         case elfcpp::Tag_ABI_WMMX_args:
9641           if (in_attr[i].int_value() != out_attr[i].int_value())
9642             {
9643               gold_error(_("%s uses iWMMXt register arguments, output does "
9644                            "not"),
9645                          name);
9646             }
9647           break;
9648         case Object_attribute::Tag_compatibility:
9649           // Merged in target-independent code.
9650           break;
9651         case elfcpp::Tag_ABI_HardFP_use:
9652           // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
9653           if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
9654               || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
9655             out_attr[i].set_int_value(3);
9656           else if (in_attr[i].int_value() > out_attr[i].int_value())
9657             out_attr[i].set_int_value(in_attr[i].int_value());
9658           break;
9659         case elfcpp::Tag_ABI_FP_16bit_format:
9660           if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
9661             {
9662               if (in_attr[i].int_value() != out_attr[i].int_value())
9663                 gold_error(_("fp16 format mismatch between %s and output"),
9664                            name);
9665             }
9666           if (in_attr[i].int_value() != 0)
9667             out_attr[i].set_int_value(in_attr[i].int_value());
9668           break;
9669
9670         case elfcpp::Tag_nodefaults:
9671           // This tag is set if it exists, but the value is unused (and is
9672           // typically zero).  We don't actually need to do anything here -
9673           // the merge happens automatically when the type flags are merged
9674           // below.
9675           break;
9676         case elfcpp::Tag_also_compatible_with:
9677           // Already done in Tag_CPU_arch.
9678           break;
9679         case elfcpp::Tag_conformance:
9680           // Keep the attribute if it matches.  Throw it away otherwise.
9681           // No attribute means no claim to conform.
9682           if (in_attr[i].string_value() != out_attr[i].string_value())
9683             out_attr[i].set_string_value("");
9684           break;
9685
9686         default:
9687           {
9688             const char* err_object = NULL;
9689
9690             // The "known_obj_attributes" table does contain some undefined
9691             // attributes.  Ensure that there are unused.
9692             if (out_attr[i].int_value() != 0
9693                 || out_attr[i].string_value() != "")
9694               err_object = "output";
9695             else if (in_attr[i].int_value() != 0
9696                      || in_attr[i].string_value() != "")
9697               err_object = name;
9698
9699             if (err_object != NULL)
9700               {
9701                 // Attribute numbers >=64 (mod 128) can be safely ignored.
9702                 if ((i & 127) < 64)
9703                   gold_error(_("%s: unknown mandatory EABI object attribute "
9704                                "%d"),
9705                              err_object, i);
9706                 else
9707                   gold_warning(_("%s: unknown EABI object attribute %d"),
9708                                err_object, i);
9709               }
9710
9711             // Only pass on attributes that match in both inputs.
9712             if (!in_attr[i].matches(out_attr[i]))
9713               {
9714                 out_attr[i].set_int_value(0);
9715                 out_attr[i].set_string_value("");
9716               }
9717           }
9718         }
9719
9720       // If out_attr was copied from in_attr then it won't have a type yet.
9721       if (in_attr[i].type() && !out_attr[i].type())
9722         out_attr[i].set_type(in_attr[i].type());
9723     }
9724
9725   // Merge Tag_compatibility attributes and any common GNU ones.
9726   this->attributes_section_data_->merge(name, pasd);
9727
9728   // Check for any attributes not known on ARM.
9729   typedef Vendor_object_attributes::Other_attributes Other_attributes;
9730   const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
9731   Other_attributes::const_iterator in_iter = in_other_attributes->begin();
9732   Other_attributes* out_other_attributes =
9733     this->attributes_section_data_->other_attributes(vendor);
9734   Other_attributes::iterator out_iter = out_other_attributes->begin();
9735
9736   while (in_iter != in_other_attributes->end()
9737          || out_iter != out_other_attributes->end())
9738     {
9739       const char* err_object = NULL;
9740       int err_tag = 0;
9741
9742       // The tags for each list are in numerical order.
9743       // If the tags are equal, then merge.
9744       if (out_iter != out_other_attributes->end()
9745           && (in_iter == in_other_attributes->end()
9746               || in_iter->first > out_iter->first))
9747         {
9748           // This attribute only exists in output.  We can't merge, and we
9749           // don't know what the tag means, so delete it.
9750           err_object = "output";
9751           err_tag = out_iter->first;
9752           int saved_tag = out_iter->first;
9753           delete out_iter->second;
9754           out_other_attributes->erase(out_iter); 
9755           out_iter = out_other_attributes->upper_bound(saved_tag);
9756         }
9757       else if (in_iter != in_other_attributes->end()
9758                && (out_iter != out_other_attributes->end()
9759                    || in_iter->first < out_iter->first))
9760         {
9761           // This attribute only exists in input. We can't merge, and we
9762           // don't know what the tag means, so ignore it.
9763           err_object = name;
9764           err_tag = in_iter->first;
9765           ++in_iter;
9766         }
9767       else // The tags are equal.
9768         {
9769           // As present, all attributes in the list are unknown, and
9770           // therefore can't be merged meaningfully.
9771           err_object = "output";
9772           err_tag = out_iter->first;
9773
9774           //  Only pass on attributes that match in both inputs.
9775           if (!in_iter->second->matches(*(out_iter->second)))
9776             {
9777               // No match.  Delete the attribute.
9778               int saved_tag = out_iter->first;
9779               delete out_iter->second;
9780               out_other_attributes->erase(out_iter);
9781               out_iter = out_other_attributes->upper_bound(saved_tag);
9782             }
9783           else
9784             {
9785               // Matched.  Keep the attribute and move to the next.
9786               ++out_iter;
9787               ++in_iter;
9788             }
9789         }
9790
9791       if (err_object)
9792         {
9793           // Attribute numbers >=64 (mod 128) can be safely ignored.  */
9794           if ((err_tag & 127) < 64)
9795             {
9796               gold_error(_("%s: unknown mandatory EABI object attribute %d"),
9797                          err_object, err_tag);
9798             }
9799           else
9800             {
9801               gold_warning(_("%s: unknown EABI object attribute %d"),
9802                            err_object, err_tag);
9803             }
9804         }
9805     }
9806 }
9807
9808 // Stub-generation methods for Target_arm.
9809
9810 // Make a new Arm_input_section object.
9811
9812 template<bool big_endian>
9813 Arm_input_section<big_endian>*
9814 Target_arm<big_endian>::new_arm_input_section(
9815     Relobj* relobj,
9816     unsigned int shndx)
9817 {
9818   Section_id sid(relobj, shndx);
9819
9820   Arm_input_section<big_endian>* arm_input_section =
9821     new Arm_input_section<big_endian>(relobj, shndx);
9822   arm_input_section->init();
9823
9824   // Register new Arm_input_section in map for look-up.
9825   std::pair<typename Arm_input_section_map::iterator, bool> ins =
9826     this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
9827
9828   // Make sure that it we have not created another Arm_input_section
9829   // for this input section already.
9830   gold_assert(ins.second);
9831
9832   return arm_input_section; 
9833 }
9834
9835 // Find the Arm_input_section object corresponding to the SHNDX-th input
9836 // section of RELOBJ.
9837
9838 template<bool big_endian>
9839 Arm_input_section<big_endian>*
9840 Target_arm<big_endian>::find_arm_input_section(
9841     Relobj* relobj,
9842     unsigned int shndx) const
9843 {
9844   Section_id sid(relobj, shndx);
9845   typename Arm_input_section_map::const_iterator p =
9846     this->arm_input_section_map_.find(sid);
9847   return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
9848 }
9849
9850 // Make a new stub table.
9851
9852 template<bool big_endian>
9853 Stub_table<big_endian>*
9854 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
9855 {
9856   Stub_table<big_endian>* stub_table =
9857     new Stub_table<big_endian>(owner);
9858   this->stub_tables_.push_back(stub_table);
9859
9860   stub_table->set_address(owner->address() + owner->data_size());
9861   stub_table->set_file_offset(owner->offset() + owner->data_size());
9862   stub_table->finalize_data_size();
9863
9864   return stub_table;
9865 }
9866
9867 // Scan a relocation for stub generation.
9868
9869 template<bool big_endian>
9870 void
9871 Target_arm<big_endian>::scan_reloc_for_stub(
9872     const Relocate_info<32, big_endian>* relinfo,
9873     unsigned int r_type,
9874     const Sized_symbol<32>* gsym,
9875     unsigned int r_sym,
9876     const Symbol_value<32>* psymval,
9877     elfcpp::Elf_types<32>::Elf_Swxword addend,
9878     Arm_address address)
9879 {
9880   typedef typename Target_arm<big_endian>::Relocate Relocate;
9881
9882   const Arm_relobj<big_endian>* arm_relobj =
9883     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9884
9885   bool target_is_thumb;
9886   Symbol_value<32> symval;
9887   if (gsym != NULL)
9888     {
9889       // This is a global symbol.  Determine if we use PLT and if the
9890       // final target is THUMB.
9891       if (gsym->use_plt_offset(Relocate::reloc_is_non_pic(r_type)))
9892         {
9893           // This uses a PLT, change the symbol value.
9894           symval.set_output_value(this->plt_section()->address()
9895                                   + gsym->plt_offset());
9896           psymval = &symval;
9897           target_is_thumb = false;
9898         }
9899       else if (gsym->is_undefined())
9900         // There is no need to generate a stub symbol is undefined.
9901         return;
9902       else
9903         {
9904           target_is_thumb =
9905             ((gsym->type() == elfcpp::STT_ARM_TFUNC)
9906              || (gsym->type() == elfcpp::STT_FUNC
9907                  && !gsym->is_undefined()
9908                  && ((psymval->value(arm_relobj, 0) & 1) != 0)));
9909         }
9910     }
9911   else
9912     {
9913       // This is a local symbol.  Determine if the final target is THUMB.
9914       target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
9915     }
9916
9917   // Strip LSB if this points to a THUMB target.
9918   const Arm_reloc_property* reloc_property =
9919     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9920   gold_assert(reloc_property != NULL);
9921   if (target_is_thumb
9922       && reloc_property->uses_thumb_bit()
9923       && ((psymval->value(arm_relobj, 0) & 1) != 0))
9924     {
9925       Arm_address stripped_value =
9926         psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
9927       symval.set_output_value(stripped_value);
9928       psymval = &symval;
9929     } 
9930
9931   // Get the symbol value.
9932   Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
9933
9934   // Owing to pipelining, the PC relative branches below actually skip
9935   // two instructions when the branch offset is 0.
9936   Arm_address destination;
9937   switch (r_type)
9938     {
9939     case elfcpp::R_ARM_CALL:
9940     case elfcpp::R_ARM_JUMP24:
9941     case elfcpp::R_ARM_PLT32:
9942       // ARM branches.
9943       destination = value + addend + 8;
9944       break;
9945     case elfcpp::R_ARM_THM_CALL:
9946     case elfcpp::R_ARM_THM_XPC22:
9947     case elfcpp::R_ARM_THM_JUMP24:
9948     case elfcpp::R_ARM_THM_JUMP19:
9949       // THUMB branches.
9950       destination = value + addend + 4;
9951       break;
9952     default:
9953       gold_unreachable();
9954     }
9955
9956   Reloc_stub* stub = NULL;
9957   Stub_type stub_type =
9958     Reloc_stub::stub_type_for_reloc(r_type, address, destination,
9959                                     target_is_thumb);
9960   if (stub_type != arm_stub_none)
9961     {
9962       // Try looking up an existing stub from a stub table.
9963       Stub_table<big_endian>* stub_table = 
9964         arm_relobj->stub_table(relinfo->data_shndx);
9965       gold_assert(stub_table != NULL);
9966    
9967       // Locate stub by destination.
9968       Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
9969
9970       // Create a stub if there is not one already
9971       stub = stub_table->find_reloc_stub(stub_key);
9972       if (stub == NULL)
9973         {
9974           // create a new stub and add it to stub table.
9975           stub = this->stub_factory().make_reloc_stub(stub_type);
9976           stub_table->add_reloc_stub(stub, stub_key);
9977         }
9978
9979       // Record the destination address.
9980       stub->set_destination_address(destination
9981                                     | (target_is_thumb ? 1 : 0));
9982     }
9983
9984   // For Cortex-A8, we need to record a relocation at 4K page boundary.
9985   if (this->fix_cortex_a8_
9986       && (r_type == elfcpp::R_ARM_THM_JUMP24
9987           || r_type == elfcpp::R_ARM_THM_JUMP19
9988           || r_type == elfcpp::R_ARM_THM_CALL
9989           || r_type == elfcpp::R_ARM_THM_XPC22)
9990       && (address & 0xfffU) == 0xffeU)
9991     {
9992       // Found a candidate.  Note we haven't checked the destination is
9993       // within 4K here: if we do so (and don't create a record) we can't
9994       // tell that a branch should have been relocated when scanning later.
9995       this->cortex_a8_relocs_info_[address] =
9996         new Cortex_a8_reloc(stub, r_type,
9997                             destination | (target_is_thumb ? 1 : 0));
9998     }
9999 }
10000
10001 // This function scans a relocation sections for stub generation.
10002 // The template parameter Relocate must be a class type which provides
10003 // a single function, relocate(), which implements the machine
10004 // specific part of a relocation.
10005
10006 // BIG_ENDIAN is the endianness of the data.  SH_TYPE is the section type:
10007 // SHT_REL or SHT_RELA.
10008
10009 // PRELOCS points to the relocation data.  RELOC_COUNT is the number
10010 // of relocs.  OUTPUT_SECTION is the output section.
10011 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
10012 // mapped to output offsets.
10013
10014 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
10015 // VIEW_SIZE is the size.  These refer to the input section, unless
10016 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
10017 // the output section.
10018
10019 template<bool big_endian>
10020 template<int sh_type>
10021 void inline
10022 Target_arm<big_endian>::scan_reloc_section_for_stubs(
10023     const Relocate_info<32, big_endian>* relinfo,
10024     const unsigned char* prelocs,
10025     size_t reloc_count,
10026     Output_section* output_section,
10027     bool needs_special_offset_handling,
10028     const unsigned char* view,
10029     elfcpp::Elf_types<32>::Elf_Addr view_address,
10030     section_size_type)
10031 {
10032   typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
10033   const int reloc_size =
10034     Reloc_types<sh_type, 32, big_endian>::reloc_size;
10035
10036   Arm_relobj<big_endian>* arm_object =
10037     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10038   unsigned int local_count = arm_object->local_symbol_count();
10039
10040   Comdat_behavior comdat_behavior = CB_UNDETERMINED;
10041
10042   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
10043     {
10044       Reltype reloc(prelocs);
10045
10046       typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
10047       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
10048       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
10049
10050       r_type = this->get_real_reloc_type(r_type);
10051
10052       // Only a few relocation types need stubs.
10053       if ((r_type != elfcpp::R_ARM_CALL)
10054          && (r_type != elfcpp::R_ARM_JUMP24)
10055          && (r_type != elfcpp::R_ARM_PLT32)
10056          && (r_type != elfcpp::R_ARM_THM_CALL)
10057          && (r_type != elfcpp::R_ARM_THM_XPC22)
10058          && (r_type != elfcpp::R_ARM_THM_JUMP24)
10059          && (r_type != elfcpp::R_ARM_THM_JUMP19)
10060          && (r_type != elfcpp::R_ARM_V4BX))
10061         continue;
10062
10063       section_offset_type offset =
10064         convert_to_section_size_type(reloc.get_r_offset());
10065
10066       if (needs_special_offset_handling)
10067         {
10068           offset = output_section->output_offset(relinfo->object,
10069                                                  relinfo->data_shndx,
10070                                                  offset);
10071           if (offset == -1)
10072             continue;
10073         }
10074
10075       // Create a v4bx stub if --fix-v4bx-interworking is used.
10076       if (r_type == elfcpp::R_ARM_V4BX)
10077         {
10078           if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
10079             {
10080               // Get the BX instruction.
10081               typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
10082               const Valtype* wv =
10083                 reinterpret_cast<const Valtype*>(view + offset);
10084               elfcpp::Elf_types<32>::Elf_Swxword insn =
10085                 elfcpp::Swap<32, big_endian>::readval(wv);
10086               const uint32_t reg = (insn & 0xf);
10087
10088               if (reg < 0xf)
10089                 {
10090                   // Try looking up an existing stub from a stub table.
10091                   Stub_table<big_endian>* stub_table =
10092                     arm_object->stub_table(relinfo->data_shndx);
10093                   gold_assert(stub_table != NULL);
10094
10095                   if (stub_table->find_arm_v4bx_stub(reg) == NULL)
10096                     {
10097                       // create a new stub and add it to stub table.
10098                       Arm_v4bx_stub* stub =
10099                         this->stub_factory().make_arm_v4bx_stub(reg);
10100                       gold_assert(stub != NULL);
10101                       stub_table->add_arm_v4bx_stub(stub);
10102                     }
10103                 }
10104             }
10105           continue;
10106         }
10107
10108       // Get the addend.
10109       Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
10110       elfcpp::Elf_types<32>::Elf_Swxword addend =
10111         stub_addend_reader(r_type, view + offset, reloc);
10112
10113       const Sized_symbol<32>* sym;
10114
10115       Symbol_value<32> symval;
10116       const Symbol_value<32> *psymval;
10117       if (r_sym < local_count)
10118         {
10119           sym = NULL;
10120           psymval = arm_object->local_symbol(r_sym);
10121
10122           // If the local symbol belongs to a section we are discarding,
10123           // and that section is a debug section, try to find the
10124           // corresponding kept section and map this symbol to its
10125           // counterpart in the kept section.  The symbol must not 
10126           // correspond to a section we are folding.
10127           bool is_ordinary;
10128           unsigned int shndx = psymval->input_shndx(&is_ordinary);
10129           if (is_ordinary
10130               && shndx != elfcpp::SHN_UNDEF
10131               && !arm_object->is_section_included(shndx) 
10132               && !(relinfo->symtab->is_section_folded(arm_object, shndx)))
10133             {
10134               if (comdat_behavior == CB_UNDETERMINED)
10135                 {
10136                   std::string name =
10137                     arm_object->section_name(relinfo->data_shndx);
10138                   comdat_behavior = get_comdat_behavior(name.c_str());
10139                 }
10140               if (comdat_behavior == CB_PRETEND)
10141                 {
10142                   bool found;
10143                   typename elfcpp::Elf_types<32>::Elf_Addr value =
10144                     arm_object->map_to_kept_section(shndx, &found);
10145                   if (found)
10146                     symval.set_output_value(value + psymval->input_value());
10147                   else
10148                     symval.set_output_value(0);
10149                 }
10150               else
10151                 {
10152                   symval.set_output_value(0);
10153                 }
10154               symval.set_no_output_symtab_entry();
10155               psymval = &symval;
10156             }
10157         }
10158       else
10159         {
10160           const Symbol* gsym = arm_object->global_symbol(r_sym);
10161           gold_assert(gsym != NULL);
10162           if (gsym->is_forwarder())
10163             gsym = relinfo->symtab->resolve_forwards(gsym);
10164
10165           sym = static_cast<const Sized_symbol<32>*>(gsym);
10166           if (sym->has_symtab_index())
10167             symval.set_output_symtab_index(sym->symtab_index());
10168           else
10169             symval.set_no_output_symtab_entry();
10170
10171           // We need to compute the would-be final value of this global
10172           // symbol.
10173           const Symbol_table* symtab = relinfo->symtab;
10174           const Sized_symbol<32>* sized_symbol =
10175             symtab->get_sized_symbol<32>(gsym);
10176           Symbol_table::Compute_final_value_status status;
10177           Arm_address value =
10178             symtab->compute_final_value<32>(sized_symbol, &status);
10179
10180           // Skip this if the symbol has not output section.
10181           if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
10182             continue;
10183
10184           symval.set_output_value(value);
10185           psymval = &symval;
10186         }
10187
10188       // If symbol is a section symbol, we don't know the actual type of
10189       // destination.  Give up.
10190       if (psymval->is_section_symbol())
10191         continue;
10192
10193       this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
10194                                 addend, view_address + offset);
10195     }
10196 }
10197
10198 // Scan an input section for stub generation.
10199
10200 template<bool big_endian>
10201 void
10202 Target_arm<big_endian>::scan_section_for_stubs(
10203     const Relocate_info<32, big_endian>* relinfo,
10204     unsigned int sh_type,
10205     const unsigned char* prelocs,
10206     size_t reloc_count,
10207     Output_section* output_section,
10208     bool needs_special_offset_handling,
10209     const unsigned char* view,
10210     Arm_address view_address,
10211     section_size_type view_size)
10212 {
10213   if (sh_type == elfcpp::SHT_REL)
10214     this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
10215         relinfo,
10216         prelocs,
10217         reloc_count,
10218         output_section,
10219         needs_special_offset_handling,
10220         view,
10221         view_address,
10222         view_size);
10223   else if (sh_type == elfcpp::SHT_RELA)
10224     // We do not support RELA type relocations yet.  This is provided for
10225     // completeness.
10226     this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
10227         relinfo,
10228         prelocs,
10229         reloc_count,
10230         output_section,
10231         needs_special_offset_handling,
10232         view,
10233         view_address,
10234         view_size);
10235   else
10236     gold_unreachable();
10237 }
10238
10239 // Group input sections for stub generation.
10240 //
10241 // We goup input sections in an output sections so that the total size,
10242 // including any padding space due to alignment is smaller than GROUP_SIZE
10243 // unless the only input section in group is bigger than GROUP_SIZE already.
10244 // Then an ARM stub table is created to follow the last input section
10245 // in group.  For each group an ARM stub table is created an is placed
10246 // after the last group.  If STUB_ALWATS_AFTER_BRANCH is false, we further
10247 // extend the group after the stub table.
10248
10249 template<bool big_endian>
10250 void
10251 Target_arm<big_endian>::group_sections(
10252     Layout* layout,
10253     section_size_type group_size,
10254     bool stubs_always_after_branch)
10255 {
10256   // Group input sections and insert stub table
10257   Layout::Section_list section_list;
10258   layout->get_allocated_sections(&section_list);
10259   for (Layout::Section_list::const_iterator p = section_list.begin();
10260        p != section_list.end();
10261        ++p)
10262     {
10263       Arm_output_section<big_endian>* output_section =
10264         Arm_output_section<big_endian>::as_arm_output_section(*p);
10265       output_section->group_sections(group_size, stubs_always_after_branch,
10266                                      this);
10267     }
10268 }
10269
10270 // Relaxation hook.  This is where we do stub generation.
10271
10272 template<bool big_endian>
10273 bool
10274 Target_arm<big_endian>::do_relax(
10275     int pass,
10276     const Input_objects* input_objects,
10277     Symbol_table* symtab,
10278     Layout* layout)
10279 {
10280   // No need to generate stubs if this is a relocatable link.
10281   gold_assert(!parameters->options().relocatable());
10282
10283   // If this is the first pass, we need to group input sections into
10284   // stub groups.
10285   bool done_exidx_fixup = false;
10286   if (pass == 1)
10287     {
10288       // Determine the stub group size.  The group size is the absolute
10289       // value of the parameter --stub-group-size.  If --stub-group-size
10290       // is passed a negative value, we restict stubs to be always after
10291       // the stubbed branches.
10292       int32_t stub_group_size_param =
10293         parameters->options().stub_group_size();
10294       bool stubs_always_after_branch = stub_group_size_param < 0;
10295       section_size_type stub_group_size = abs(stub_group_size_param);
10296
10297       // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
10298       // page as the first half of a 32-bit branch straddling two 4K pages.
10299       // This is a crude way of enforcing that.
10300       if (this->fix_cortex_a8_)
10301         stubs_always_after_branch = true;
10302
10303       if (stub_group_size == 1)
10304         {
10305           // Default value.
10306           // Thumb branch range is +-4MB has to be used as the default
10307           // maximum size (a given section can contain both ARM and Thumb
10308           // code, so the worst case has to be taken into account).
10309           //
10310           // This value is 24K less than that, which allows for 2025
10311           // 12-byte stubs.  If we exceed that, then we will fail to link.
10312           // The user will have to relink with an explicit group size
10313           // option.
10314           stub_group_size = 4170000;
10315         }
10316
10317       group_sections(layout, stub_group_size, stubs_always_after_branch);
10318      
10319       // Also fix .ARM.exidx section coverage.
10320       Output_section* os = layout->find_output_section(".ARM.exidx");
10321       if (os != NULL && os->type() == elfcpp::SHT_ARM_EXIDX)
10322         {
10323           Arm_output_section<big_endian>* exidx_output_section =
10324             Arm_output_section<big_endian>::as_arm_output_section(os);
10325           this->fix_exidx_coverage(layout, exidx_output_section, symtab);
10326           done_exidx_fixup = true;
10327         }
10328     }
10329
10330   // The Cortex-A8 stubs are sensitive to layout of code sections.  At the
10331   // beginning of each relaxation pass, just blow away all the stubs.
10332   // Alternatively, we could selectively remove only the stubs and reloc
10333   // information for code sections that have moved since the last pass.
10334   // That would require more book-keeping.
10335   typedef typename Stub_table_list::iterator Stub_table_iterator;
10336   if (this->fix_cortex_a8_)
10337     {
10338       // Clear all Cortex-A8 reloc information.
10339       for (typename Cortex_a8_relocs_info::const_iterator p =
10340              this->cortex_a8_relocs_info_.begin();
10341            p != this->cortex_a8_relocs_info_.end();
10342            ++p)
10343         delete p->second;
10344       this->cortex_a8_relocs_info_.clear();
10345
10346       // Remove all Cortex-A8 stubs.
10347       for (Stub_table_iterator sp = this->stub_tables_.begin();
10348            sp != this->stub_tables_.end();
10349            ++sp)
10350         (*sp)->remove_all_cortex_a8_stubs();
10351     }
10352   
10353   // Scan relocs for relocation stubs
10354   for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
10355        op != input_objects->relobj_end();
10356        ++op)
10357     {
10358       Arm_relobj<big_endian>* arm_relobj =
10359         Arm_relobj<big_endian>::as_arm_relobj(*op);
10360       arm_relobj->scan_sections_for_stubs(this, symtab, layout);
10361     }
10362
10363   // Check all stub tables to see if any of them have their data sizes
10364   // or addresses alignments changed.  These are the only things that
10365   // matter.
10366   bool any_stub_table_changed = false;
10367   Unordered_set<const Output_section*> sections_needing_adjustment;
10368   for (Stub_table_iterator sp = this->stub_tables_.begin();
10369        (sp != this->stub_tables_.end()) && !any_stub_table_changed;
10370        ++sp)
10371     {
10372       if ((*sp)->update_data_size_and_addralign())
10373         {
10374           // Update data size of stub table owner.
10375           Arm_input_section<big_endian>* owner = (*sp)->owner();
10376           uint64_t address = owner->address();
10377           off_t offset = owner->offset();
10378           owner->reset_address_and_file_offset();
10379           owner->set_address_and_file_offset(address, offset);
10380
10381           sections_needing_adjustment.insert(owner->output_section());
10382           any_stub_table_changed = true;
10383         }
10384     }
10385
10386   // Output_section_data::output_section() returns a const pointer but we
10387   // need to update output sections, so we record all output sections needing
10388   // update above and scan the sections here to find out what sections need
10389   // to be updated.
10390   for(Layout::Section_list::const_iterator p = layout->section_list().begin();
10391       p != layout->section_list().end();
10392       ++p)
10393     {
10394       if (sections_needing_adjustment.find(*p)
10395           != sections_needing_adjustment.end())
10396         (*p)->set_section_offsets_need_adjustment();
10397     }
10398
10399   // Stop relaxation if no EXIDX fix-up and no stub table change.
10400   bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
10401
10402   // Finalize the stubs in the last relaxation pass.
10403   if (!continue_relaxation)
10404     {
10405       for (Stub_table_iterator sp = this->stub_tables_.begin();
10406            (sp != this->stub_tables_.end()) && !any_stub_table_changed;
10407             ++sp)
10408         (*sp)->finalize_stubs();
10409
10410       // Update output local symbol counts of objects if necessary.
10411       for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
10412            op != input_objects->relobj_end();
10413            ++op)
10414         {
10415           Arm_relobj<big_endian>* arm_relobj =
10416             Arm_relobj<big_endian>::as_arm_relobj(*op);
10417
10418           // Update output local symbol counts.  We need to discard local
10419           // symbols defined in parts of input sections that are discarded by
10420           // relaxation.
10421           if (arm_relobj->output_local_symbol_count_needs_update())
10422             arm_relobj->update_output_local_symbol_count();
10423         }
10424     }
10425
10426   return continue_relaxation;
10427 }
10428
10429 // Relocate a stub.
10430
10431 template<bool big_endian>
10432 void
10433 Target_arm<big_endian>::relocate_stub(
10434     Stub* stub,
10435     const Relocate_info<32, big_endian>* relinfo,
10436     Output_section* output_section,
10437     unsigned char* view,
10438     Arm_address address,
10439     section_size_type view_size)
10440 {
10441   Relocate relocate;
10442   const Stub_template* stub_template = stub->stub_template();
10443   for (size_t i = 0; i < stub_template->reloc_count(); i++)
10444     {
10445       size_t reloc_insn_index = stub_template->reloc_insn_index(i);
10446       const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
10447
10448       unsigned int r_type = insn->r_type();
10449       section_size_type reloc_offset = stub_template->reloc_offset(i);
10450       section_size_type reloc_size = insn->size();
10451       gold_assert(reloc_offset + reloc_size <= view_size);
10452
10453       // This is the address of the stub destination.
10454       Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
10455       Symbol_value<32> symval;
10456       symval.set_output_value(target);
10457
10458       // Synthesize a fake reloc just in case.  We don't have a symbol so
10459       // we use 0.
10460       unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
10461       memset(reloc_buffer, 0, sizeof(reloc_buffer));
10462       elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
10463       reloc_write.put_r_offset(reloc_offset);
10464       reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
10465       elfcpp::Rel<32, big_endian> rel(reloc_buffer);
10466
10467       relocate.relocate(relinfo, this, output_section,
10468                         this->fake_relnum_for_stubs, rel, r_type,
10469                         NULL, &symval, view + reloc_offset,
10470                         address + reloc_offset, reloc_size);
10471     }
10472 }
10473
10474 // Determine whether an object attribute tag takes an integer, a
10475 // string or both.
10476
10477 template<bool big_endian>
10478 int
10479 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
10480 {
10481   if (tag == Object_attribute::Tag_compatibility)
10482     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
10483             | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
10484   else if (tag == elfcpp::Tag_nodefaults)
10485     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
10486             | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
10487   else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
10488     return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
10489   else if (tag < 32)
10490     return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
10491   else
10492     return ((tag & 1) != 0
10493             ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
10494             : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
10495 }
10496
10497 // Reorder attributes.
10498 //
10499 // The ABI defines that Tag_conformance should be emitted first, and that
10500 // Tag_nodefaults should be second (if either is defined).  This sets those
10501 // two positions, and bumps up the position of all the remaining tags to
10502 // compensate.
10503
10504 template<bool big_endian>
10505 int
10506 Target_arm<big_endian>::do_attributes_order(int num) const
10507 {
10508   // Reorder the known object attributes in output.  We want to move
10509   // Tag_conformance to position 4 and Tag_conformance to position 5
10510   // and shift eveything between 4 .. Tag_conformance - 1 to make room.
10511   if (num == 4)
10512     return elfcpp::Tag_conformance;
10513   if (num == 5)
10514     return elfcpp::Tag_nodefaults;
10515   if ((num - 2) < elfcpp::Tag_nodefaults)
10516     return num - 2;
10517   if ((num - 1) < elfcpp::Tag_conformance)
10518     return num - 1;
10519   return num;
10520 }
10521
10522 // Scan a span of THUMB code for Cortex-A8 erratum.
10523
10524 template<bool big_endian>
10525 void
10526 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
10527     Arm_relobj<big_endian>* arm_relobj,
10528     unsigned int shndx,
10529     section_size_type span_start,
10530     section_size_type span_end,
10531     const unsigned char* view,
10532     Arm_address address)
10533 {
10534   // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
10535   //
10536   // The opcode is BLX.W, BL.W, B.W, Bcc.W
10537   // The branch target is in the same 4KB region as the
10538   // first half of the branch.
10539   // The instruction before the branch is a 32-bit
10540   // length non-branch instruction.
10541   section_size_type i = span_start;
10542   bool last_was_32bit = false;
10543   bool last_was_branch = false;
10544   while (i < span_end)
10545     {
10546       typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
10547       const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
10548       uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
10549       bool is_blx = false, is_b = false;
10550       bool is_bl = false, is_bcc = false;
10551
10552       bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
10553       if (insn_32bit)
10554         {
10555           // Load the rest of the insn (in manual-friendly order).
10556           insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
10557
10558           // Encoding T4: B<c>.W.
10559           is_b = (insn & 0xf800d000U) == 0xf0009000U;
10560           // Encoding T1: BL<c>.W.
10561           is_bl = (insn & 0xf800d000U) == 0xf000d000U;
10562           // Encoding T2: BLX<c>.W.
10563           is_blx = (insn & 0xf800d000U) == 0xf000c000U;
10564           // Encoding T3: B<c>.W (not permitted in IT block).
10565           is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
10566                     && (insn & 0x07f00000U) != 0x03800000U);
10567         }
10568
10569       bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
10570                            
10571       // If this instruction is a 32-bit THUMB branch that crosses a 4K
10572       // page boundary and it follows 32-bit non-branch instruction,
10573       // we need to work around.
10574       if (is_32bit_branch
10575           && ((address + i) & 0xfffU) == 0xffeU
10576           && last_was_32bit
10577           && !last_was_branch)
10578         {
10579           // Check to see if there is a relocation stub for this branch.
10580           bool force_target_arm = false;
10581           bool force_target_thumb = false;
10582           const Cortex_a8_reloc* cortex_a8_reloc = NULL;
10583           Cortex_a8_relocs_info::const_iterator p =
10584             this->cortex_a8_relocs_info_.find(address + i);
10585
10586           if (p != this->cortex_a8_relocs_info_.end())
10587             {
10588               cortex_a8_reloc = p->second;
10589               bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
10590
10591               if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
10592                   && !target_is_thumb)
10593                 force_target_arm = true;
10594               else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
10595                        && target_is_thumb)
10596                 force_target_thumb = true;
10597             }
10598
10599           off_t offset;
10600           Stub_type stub_type = arm_stub_none;
10601
10602           // Check if we have an offending branch instruction.
10603           uint16_t upper_insn = (insn >> 16) & 0xffffU;
10604           uint16_t lower_insn = insn & 0xffffU;
10605           typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
10606
10607           if (cortex_a8_reloc != NULL
10608               && cortex_a8_reloc->reloc_stub() != NULL)
10609             // We've already made a stub for this instruction, e.g.
10610             // it's a long branch or a Thumb->ARM stub.  Assume that
10611             // stub will suffice to work around the A8 erratum (see
10612             // setting of always_after_branch above).
10613             ;
10614           else if (is_bcc)
10615             {
10616               offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
10617                                                               lower_insn);
10618               stub_type = arm_stub_a8_veneer_b_cond;
10619             }
10620           else if (is_b || is_bl || is_blx)
10621             {
10622               offset = RelocFuncs::thumb32_branch_offset(upper_insn,
10623                                                          lower_insn);
10624               if (is_blx)
10625                 offset &= ~3;
10626
10627               stub_type = (is_blx
10628                            ? arm_stub_a8_veneer_blx
10629                            : (is_bl
10630                               ? arm_stub_a8_veneer_bl
10631                               : arm_stub_a8_veneer_b));
10632             }
10633
10634           if (stub_type != arm_stub_none)
10635             {
10636               Arm_address pc_for_insn = address + i + 4;
10637
10638               // The original instruction is a BL, but the target is
10639               // an ARM instruction.  If we were not making a stub,
10640               // the BL would have been converted to a BLX.  Use the
10641               // BLX stub instead in that case.
10642               if (this->may_use_blx() && force_target_arm
10643                   && stub_type == arm_stub_a8_veneer_bl)
10644                 {
10645                   stub_type = arm_stub_a8_veneer_blx;
10646                   is_blx = true;
10647                   is_bl = false;
10648                 }
10649               // Conversely, if the original instruction was
10650               // BLX but the target is Thumb mode, use the BL stub.
10651               else if (force_target_thumb
10652                        && stub_type == arm_stub_a8_veneer_blx)
10653                 {
10654                   stub_type = arm_stub_a8_veneer_bl;
10655                   is_blx = false;
10656                   is_bl = true;
10657                 }
10658
10659               if (is_blx)
10660                 pc_for_insn &= ~3;
10661
10662               // If we found a relocation, use the proper destination,
10663               // not the offset in the (unrelocated) instruction.
10664               // Note this is always done if we switched the stub type above.
10665               if (cortex_a8_reloc != NULL)
10666                 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
10667
10668               Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
10669
10670               // Add a new stub if destination address in in the same page.
10671               if (((address + i) & ~0xfffU) == (target & ~0xfffU))
10672                 {
10673                   Cortex_a8_stub* stub =
10674                     this->stub_factory_.make_cortex_a8_stub(stub_type,
10675                                                             arm_relobj, shndx,
10676                                                             address + i,
10677                                                             target, insn);
10678                   Stub_table<big_endian>* stub_table =
10679                     arm_relobj->stub_table(shndx);
10680                   gold_assert(stub_table != NULL);
10681                   stub_table->add_cortex_a8_stub(address + i, stub);
10682                 }
10683             }
10684         }
10685
10686       i += insn_32bit ? 4 : 2;
10687       last_was_32bit = insn_32bit;
10688       last_was_branch = is_32bit_branch;
10689     }
10690 }
10691
10692 // Apply the Cortex-A8 workaround.
10693
10694 template<bool big_endian>
10695 void
10696 Target_arm<big_endian>::apply_cortex_a8_workaround(
10697     const Cortex_a8_stub* stub,
10698     Arm_address stub_address,
10699     unsigned char* insn_view,
10700     Arm_address insn_address)
10701 {
10702   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
10703   Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
10704   Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
10705   Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
10706   off_t branch_offset = stub_address - (insn_address + 4);
10707
10708   typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
10709   switch (stub->stub_template()->type())
10710     {
10711     case arm_stub_a8_veneer_b_cond:
10712       gold_assert(!utils::has_overflow<21>(branch_offset));
10713       upper_insn = RelocFuncs::thumb32_cond_branch_upper(upper_insn,
10714                                                          branch_offset);
10715       lower_insn = RelocFuncs::thumb32_cond_branch_lower(lower_insn,
10716                                                          branch_offset);
10717       break;
10718
10719     case arm_stub_a8_veneer_b:
10720     case arm_stub_a8_veneer_bl:
10721     case arm_stub_a8_veneer_blx:
10722       if ((lower_insn & 0x5000U) == 0x4000U)
10723         // For a BLX instruction, make sure that the relocation is
10724         // rounded up to a word boundary.  This follows the semantics of
10725         // the instruction which specifies that bit 1 of the target
10726         // address will come from bit 1 of the base address.
10727         branch_offset = (branch_offset + 2) & ~3;
10728
10729       // Put BRANCH_OFFSET back into the insn.
10730       gold_assert(!utils::has_overflow<25>(branch_offset));
10731       upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
10732       lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
10733       break;
10734
10735     default:
10736       gold_unreachable();
10737     }
10738
10739   // Put the relocated value back in the object file:
10740   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
10741   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
10742 }
10743
10744 template<bool big_endian>
10745 class Target_selector_arm : public Target_selector
10746 {
10747  public:
10748   Target_selector_arm()
10749     : Target_selector(elfcpp::EM_ARM, 32, big_endian,
10750                       (big_endian ? "elf32-bigarm" : "elf32-littlearm"))
10751   { }
10752
10753   Target*
10754   do_instantiate_target()
10755   { return new Target_arm<big_endian>(); }
10756 };
10757
10758 // Fix .ARM.exidx section coverage.
10759
10760 template<bool big_endian>
10761 void
10762 Target_arm<big_endian>::fix_exidx_coverage(
10763     Layout* layout,
10764     Arm_output_section<big_endian>* exidx_section,
10765     Symbol_table* symtab)
10766 {
10767   // We need to look at all the input sections in output in ascending
10768   // order of of output address.  We do that by building a sorted list
10769   // of output sections by addresses.  Then we looks at the output sections
10770   // in order.  The input sections in an output section are already sorted
10771   // by addresses within the output section.
10772
10773   typedef std::set<Output_section*, output_section_address_less_than>
10774       Sorted_output_section_list;
10775   Sorted_output_section_list sorted_output_sections;
10776   Layout::Section_list section_list;
10777   layout->get_allocated_sections(&section_list);
10778   for (Layout::Section_list::const_iterator p = section_list.begin();
10779        p != section_list.end();
10780        ++p)
10781     {
10782       // We only care about output sections that contain executable code.
10783       if (((*p)->flags() & elfcpp::SHF_EXECINSTR) != 0)
10784         sorted_output_sections.insert(*p);
10785     }
10786
10787   // Go over the output sections in ascending order of output addresses.
10788   typedef typename Arm_output_section<big_endian>::Text_section_list
10789       Text_section_list;
10790   Text_section_list sorted_text_sections;
10791   for(typename Sorted_output_section_list::iterator p =
10792         sorted_output_sections.begin();
10793       p != sorted_output_sections.end();
10794       ++p)
10795     {
10796       Arm_output_section<big_endian>* arm_output_section =
10797         Arm_output_section<big_endian>::as_arm_output_section(*p);
10798       arm_output_section->append_text_sections_to_list(&sorted_text_sections);
10799     } 
10800
10801   exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab);
10802 }
10803
10804 Target_selector_arm<false> target_selector_arm;
10805 Target_selector_arm<true> target_selector_armbe;
10806
10807 } // End anonymous namespace.