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[binutils.git] / gold / arm.cc
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1 // arm.cc -- arm target support for gold.
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.
9 // This file is part of gold.
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.
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.
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.
26 #include "gold.h"
28 #include <cstring>
29 #include <limits>
30 #include <cstdio>
31 #include <string>
32 #include <algorithm>
33 #include <map>
34 #include <utility>
35 #include <set>
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"
55 namespace
58 using namespace gold;
60 template<bool big_endian>
61 class Output_data_plt_arm;
63 template<bool big_endian>
64 class Stub_table;
66 template<bool big_endian>
67 class Arm_input_section;
69 class Arm_exidx_cantunwind;
71 class Arm_exidx_merged_section;
73 class Arm_exidx_fixup;
75 template<bool big_endian>
76 class Arm_output_section;
78 class Arm_exidx_input_section;
80 template<bool big_endian>
81 class Arm_relobj;
83 template<bool big_endian>
84 class Arm_relocate_functions;
86 template<bool big_endian>
87 class Arm_output_data_got;
89 template<bool big_endian>
90 class Target_arm;
92 // For convenience.
93 typedef elfcpp::Elf_types<32>::Elf_Addr Arm_address;
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);
103 // Thread Control Block size.
104 const size_t ARM_TCB_SIZE = 8;
106 // The arm target class.
108 // This is a very simple port of gold for ARM-EABI. It is intended for
109 // supporting Android only for the time being.
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.
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.
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.
129 Arm_reloc_property_table* arm_reloc_property_table = NULL;
131 // Instruction template class. This class is similar to the insn_sequence
132 // struct in bfd/elf32-arm.c.
134 class Insn_template
136 public:
137 // Types of instruction templates.
138 enum Type
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
151 // Factory methods to create instruction templates in different formats.
153 static const Insn_template
154 thumb16_insn(uint32_t data)
155 { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 0); }
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); }
163 static const Insn_template
164 thumb32_insn(uint32_t data)
165 { return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_NONE, 0); }
167 static const Insn_template
168 thumb32_b_insn(uint32_t data, int reloc_addend)
170 return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_THM_JUMP24,
171 reloc_addend);
174 static const Insn_template
175 arm_insn(uint32_t data)
176 { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_NONE, 0); }
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); }
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); }
186 // Accessors. This class is used for read-only objects so no modifiers
187 // are provided.
189 uint32_t
190 data() const
191 { return this->data_; }
193 // Return the instruction sequence type of this.
194 Type
195 type() const
196 { return this->type_; }
198 // Return the ARM relocation type of this.
199 unsigned int
200 r_type() const
201 { return this->r_type_; }
203 int32_t
204 reloc_addend() const
205 { return this->reloc_addend_; }
207 // Return size of instruction template in bytes.
208 size_t
209 size() const;
211 // Return byte-alignment of instruction template.
212 unsigned
213 alignment() const;
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)
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_;
234 // Macro for generating code to stub types. One entry per long/short
235 // branch stub
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)
256 // Stub types.
258 #define DEF_STUB(x) arm_stub_##x,
259 typedef enum
261 arm_stub_none,
262 DEF_STUBS
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,
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,
274 // Last stub type.
275 arm_stub_type_last = arm_stub_v4_veneer_bx
276 } Stub_type;
277 #undef DEF_STUB
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.
283 class Stub_template
285 public:
286 Stub_template(Stub_type, const Insn_template*, size_t);
288 ~Stub_template()
291 // Return stub type.
292 Stub_type
293 type() const
294 { return this->type_; }
296 // Return an array of instruction templates.
297 const Insn_template*
298 insns() const
299 { return this->insns_; }
301 // Return size of template in number of instructions.
302 size_t
303 insn_count() const
304 { return this->insn_count_; }
306 // Return size of template in bytes.
307 size_t
308 size() const
309 { return this->size_; }
311 // Return alignment of the stub template.
312 unsigned
313 alignment() const
314 { return this->alignment_; }
316 // Return whether entry point is in thumb mode.
317 bool
318 entry_in_thumb_mode() const
319 { return this->entry_in_thumb_mode_; }
321 // Return number of relocations in this template.
322 size_t
323 reloc_count() const
324 { return this->relocs_.size(); }
326 // Return index of the I-th instruction with relocation.
327 size_t
328 reloc_insn_index(size_t i) const
330 gold_assert(i < this->relocs_.size());
331 return this->relocs_[i].first;
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
339 gold_assert(i < this->relocs_.size());
340 return this->relocs_[i].second;
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;
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&);
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_;
372 // A class for code stubs. This is a base class for different type of
373 // stubs used in the ARM target.
376 class Stub
378 private:
379 static const section_offset_type invalid_offset =
380 static_cast<section_offset_type>(-1);
382 public:
383 Stub(const Stub_template* stub_template)
384 : stub_template_(stub_template), offset_(invalid_offset)
387 virtual
388 ~Stub()
391 // Return the stub template.
392 const Stub_template*
393 stub_template() const
394 { return this->stub_template_; }
396 // Return offset of code stub from beginning of its containing stub table.
397 section_offset_type
398 offset() const
400 gold_assert(this->offset_ != invalid_offset);
401 return this->offset_;
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; }
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); }
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); }
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); }
426 protected:
427 // This must be defined in the child class.
428 virtual Arm_address
429 do_reloc_target(size_t) = 0;
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)
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);
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(); }
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);
453 // Its template.
454 const Stub_template* stub_template_;
455 // Offset within the section of containing this stub.
456 section_offset_type offset_;
459 // Reloc stub class. These are stubs we use to fix up relocation because
460 // of limited branch ranges.
462 class Reloc_stub : public Stub
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);
469 // Return destination address.
470 Arm_address
471 destination_address() const
473 gold_assert(this->destination_address_ != this->invalid_address);
474 return this->destination_address_;
477 // Set destination address.
478 void
479 set_destination_address(Arm_address address)
481 gold_assert(address != this->invalid_address);
482 this->destination_address_ = address;
485 // Reset destination address.
486 void
487 reset_destination_address()
488 { this->destination_address_ = this->invalid_address; }
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);
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
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)
512 if (symbol != NULL)
514 this->r_sym_ = Reloc_stub::invalid_index;
515 this->u_.symbol = symbol;
517 else
519 gold_assert(relobj != NULL && r_sym != invalid_index);
520 this->r_sym_ = r_sym;
521 this->u_.relobj = relobj;
525 ~Key()
528 // Accessors: Keys are meant to be read-only object so no modifiers are
529 // provided.
531 // Return stub type.
532 Stub_type
533 stub_type() const
534 { return this->stub_type_; }
536 // Return the local symbol index or invalid_index.
537 unsigned int
538 r_sym() const
539 { return this->r_sym_; }
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; }
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; }
551 // Whether this equals to another key k.
552 bool
553 eq(const Key& k) const
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_));
563 // Return a hash value.
564 size_t
565 hash_value() const
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_);
576 // Functors for STL associative containers.
577 struct hash
579 size_t
580 operator()(const Key& k) const
581 { return k.hash_value(); }
584 struct equal_to
586 bool
587 operator()(const Key& k1, const Key& k2) const
588 { return k1.eq(k2); }
591 // Name of key. This is mainly for debugging.
592 std::string
593 name() const;
595 private:
596 // Stub type.
597 Stub_type stub_type_;
598 // If this is a local symbol, this is the index in the defining object.
599 // Otherwise, it is invalid_index for a global symbol.
600 unsigned int r_sym_;
601 // If r_sym_ is invalid index. This points to a global symbol.
602 // Otherwise, this points a relobj. We used the unsized and target
603 // independent Symbol and Relobj classes instead of Sized_symbol<32> and
604 // Arm_relobj. This is done to avoid making the stub class a template
605 // as most of the stub machinery is endianness-neutral. However, it
606 // may require a bit of casting done by users of this class.
607 union
609 const Symbol* symbol;
610 const Relobj* relobj;
611 } u_;
612 // Addend associated with a reloc.
613 int32_t addend_;
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)
622 ~Reloc_stub()
625 friend class Stub_factory;
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)
632 // All reloc stub have only one relocation.
633 gold_assert(i == 0);
634 return this->destination_address_;
637 private:
638 // Address of destination.
639 Arm_address destination_address_;
642 // Cortex-A8 stub class. We need a Cortex-A8 stub to redirect any 32-bit
643 // THUMB branch that meets the following conditions:
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.
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.
661 class Cortex_a8_stub : public Stub
663 public:
664 ~Cortex_a8_stub()
667 // Return the object of the code section containing the branch being fixed
668 // up.
669 Relobj*
670 relobj() const
671 { return this->relobj_; }
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_; }
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_; }
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_; }
693 // Return the instruction being fixed up.
694 uint32_t
695 original_insn() const
696 { return this->original_insn_; }
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)
709 friend class Stub_factory;
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)
716 if (this->stub_template()->type() == arm_stub_a8_veneer_b_cond)
718 // The conditional branch veneer has two relocations.
719 gold_assert(i < 2);
720 return i == 0 ? this->source_address_ + 4 : this->destination_address_;
722 else
724 // All other Cortex-A8 stubs have only one relocation.
725 gold_assert(i == 0);
726 return this->destination_address_;
730 // Return an instruction for the THUMB16_SPECIAL_TYPE instruction template.
731 uint16_t
732 do_thumb16_special(size_t);
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_;
748 // ARMv4 BX Rx branch relocation stub class.
749 class Arm_v4bx_stub : public Stub
751 public:
752 ~Arm_v4bx_stub()
755 // Return the associated register.
756 uint32_t
757 reg() const
758 { return this->reg_; }
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)
766 friend class Stub_factory;
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(); }
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)
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);
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)
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_));
802 // A register index (r0-r14), which is associated with the stub.
803 uint32_t reg_;
806 // Stub factory class.
808 class Stub_factory
810 public:
811 // Return the unique instance of this class.
812 static const Stub_factory&
813 get_instance()
815 static Stub_factory singleton;
816 return singleton;
819 // Make a relocation stub.
820 Reloc_stub*
821 make_reloc_stub(Stub_type stub_type) const
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]);
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
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);
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
845 gold_assert(reg < 0xf);
846 return new Arm_v4bx_stub(this->stub_templates_[arm_stub_v4_veneer_bx],
847 reg);
850 private:
851 // Constructor and destructor are protected since we only return a single
852 // instance created in Stub_factory::get_instance().
854 Stub_factory();
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&);
860 // Stub templates. These are initialized in the constructor.
861 const Stub_template* stub_templates_[arm_stub_type_last+1];
864 // A class to hold stubs for the ARM target.
866 template<bool big_endian>
867 class Stub_table : public Output_data
869 public:
870 Stub_table(Arm_input_section<big_endian>* owner)
871 : Output_data(), owner_(owner), reloc_stubs_(), reloc_stubs_size_(0),
872 reloc_stubs_addralign_(1), cortex_a8_stubs_(), arm_v4bx_stubs_(0xf),
873 prev_data_size_(0), prev_addralign_(1)
876 ~Stub_table()
879 // Owner of this stub table.
880 Arm_input_section<big_endian>*
881 owner() const
882 { return this->owner_; }
884 // Whether this stub table is empty.
885 bool
886 empty() const
888 return (this->reloc_stubs_.empty()
889 && this->cortex_a8_stubs_.empty()
890 && this->arm_v4bx_stubs_.empty());
893 // Return the current data size.
894 off_t
895 current_data_size() const
896 { return this->current_data_size_for_child(); }
898 // Add a STUB with using KEY. Caller is reponsible for avoid adding
899 // if already a STUB with the same key has been added.
900 void
901 add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key)
903 const Stub_template* stub_template = stub->stub_template();
904 gold_assert(stub_template->type() == key.stub_type());
905 this->reloc_stubs_[key] = stub;
907 // Assign stub offset early. We can do this because we never remove
908 // reloc stubs and they are in the beginning of the stub table.
909 uint64_t align = stub_template->alignment();
910 this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_, align);
911 stub->set_offset(this->reloc_stubs_size_);
912 this->reloc_stubs_size_ += stub_template->size();
913 this->reloc_stubs_addralign_ =
914 std::max(this->reloc_stubs_addralign_, align);
917 // Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS.
918 // Caller is reponsible for avoid adding if already a STUB with the same
919 // address has been added.
920 void
921 add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub)
923 std::pair<Arm_address, Cortex_a8_stub*> value(address, stub);
924 this->cortex_a8_stubs_.insert(value);
927 // Add an ARM V4BX relocation stub. A register index will be retrieved
928 // from the stub.
929 void
930 add_arm_v4bx_stub(Arm_v4bx_stub* stub)
932 gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL);
933 this->arm_v4bx_stubs_[stub->reg()] = stub;
936 // Remove all Cortex-A8 stubs.
937 void
938 remove_all_cortex_a8_stubs();
940 // Look up a relocation stub using KEY. Return NULL if there is none.
941 Reloc_stub*
942 find_reloc_stub(const Reloc_stub::Key& key) const
944 typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
945 return (p != this->reloc_stubs_.end()) ? p->second : NULL;
948 // Look up an arm v4bx relocation stub using the register index.
949 // Return NULL if there is none.
950 Arm_v4bx_stub*
951 find_arm_v4bx_stub(const uint32_t reg) const
953 gold_assert(reg < 0xf);
954 return this->arm_v4bx_stubs_[reg];
957 // Relocate stubs in this stub table.
958 void
959 relocate_stubs(const Relocate_info<32, big_endian>*,
960 Target_arm<big_endian>*, Output_section*,
961 unsigned char*, Arm_address, section_size_type);
963 // Update data size and alignment at the end of a relaxation pass. Return
964 // true if either data size or alignment is different from that of the
965 // previous relaxation pass.
966 bool
967 update_data_size_and_addralign();
969 // Finalize stubs. Set the offsets of all stubs and mark input sections
970 // needing the Cortex-A8 workaround.
971 void
972 finalize_stubs();
974 // Apply Cortex-A8 workaround to an address range.
975 void
976 apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*,
977 unsigned char*, Arm_address,
978 section_size_type);
980 protected:
981 // Write out section contents.
982 void
983 do_write(Output_file*);
985 // Return the required alignment.
986 uint64_t
987 do_addralign() const
988 { return this->prev_addralign_; }
990 // Reset address and file offset.
991 void
992 do_reset_address_and_file_offset()
993 { this->set_current_data_size_for_child(this->prev_data_size_); }
995 // Set final data size.
996 void
997 set_final_data_size()
998 { this->set_data_size(this->current_data_size()); }
1000 private:
1001 // Relocate one stub.
1002 void
1003 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
1004 Target_arm<big_endian>*, Output_section*,
1005 unsigned char*, Arm_address, section_size_type);
1007 // Unordered map of relocation stubs.
1008 typedef
1009 Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
1010 Reloc_stub::Key::equal_to>
1011 Reloc_stub_map;
1013 // List of Cortex-A8 stubs ordered by addresses of branches being
1014 // fixed up in output.
1015 typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list;
1016 // List of Arm V4BX relocation stubs ordered by associated registers.
1017 typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list;
1019 // Owner of this stub table.
1020 Arm_input_section<big_endian>* owner_;
1021 // The relocation stubs.
1022 Reloc_stub_map reloc_stubs_;
1023 // Size of reloc stubs.
1024 off_t reloc_stubs_size_;
1025 // Maximum address alignment of reloc stubs.
1026 uint64_t reloc_stubs_addralign_;
1027 // The cortex_a8_stubs.
1028 Cortex_a8_stub_list cortex_a8_stubs_;
1029 // The Arm V4BX relocation stubs.
1030 Arm_v4bx_stub_list arm_v4bx_stubs_;
1031 // data size of this in the previous pass.
1032 off_t prev_data_size_;
1033 // address alignment of this in the previous pass.
1034 uint64_t prev_addralign_;
1037 // Arm_exidx_cantunwind class. This represents an EXIDX_CANTUNWIND entry
1038 // we add to the end of an EXIDX input section that goes into the output.
1040 class Arm_exidx_cantunwind : public Output_section_data
1042 public:
1043 Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
1044 : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
1047 // Return the object containing the section pointed by this.
1048 Relobj*
1049 relobj() const
1050 { return this->relobj_; }
1052 // Return the section index of the section pointed by this.
1053 unsigned int
1054 shndx() const
1055 { return this->shndx_; }
1057 protected:
1058 void
1059 do_write(Output_file* of)
1061 if (parameters->target().is_big_endian())
1062 this->do_fixed_endian_write<true>(of);
1063 else
1064 this->do_fixed_endian_write<false>(of);
1067 // Write to a map file.
1068 void
1069 do_print_to_mapfile(Mapfile* mapfile) const
1070 { mapfile->print_output_data(this, _("** ARM cantunwind")); }
1072 private:
1073 // Implement do_write for a given endianness.
1074 template<bool big_endian>
1075 void inline
1076 do_fixed_endian_write(Output_file*);
1078 // The object containing the section pointed by this.
1079 Relobj* relobj_;
1080 // The section index of the section pointed by this.
1081 unsigned int shndx_;
1084 // During EXIDX coverage fix-up, we compact an EXIDX section. The
1085 // Offset map is used to map input section offset within the EXIDX section
1086 // to the output offset from the start of this EXIDX section.
1088 typedef std::map<section_offset_type, section_offset_type>
1089 Arm_exidx_section_offset_map;
1091 // Arm_exidx_merged_section class. This represents an EXIDX input section
1092 // with some of its entries merged.
1094 class Arm_exidx_merged_section : public Output_relaxed_input_section
1096 public:
1097 // Constructor for Arm_exidx_merged_section.
1098 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
1099 // SECTION_OFFSET_MAP points to a section offset map describing how
1100 // parts of the input section are mapped to output. DELETED_BYTES is
1101 // the number of bytes deleted from the EXIDX input section.
1102 Arm_exidx_merged_section(
1103 const Arm_exidx_input_section& exidx_input_section,
1104 const Arm_exidx_section_offset_map& section_offset_map,
1105 uint32_t deleted_bytes);
1107 // Return the original EXIDX input section.
1108 const Arm_exidx_input_section&
1109 exidx_input_section() const
1110 { return this->exidx_input_section_; }
1112 // Return the section offset map.
1113 const Arm_exidx_section_offset_map&
1114 section_offset_map() const
1115 { return this->section_offset_map_; }
1117 protected:
1118 // Write merged section into file OF.
1119 void
1120 do_write(Output_file* of);
1122 bool
1123 do_output_offset(const Relobj*, unsigned int, section_offset_type,
1124 section_offset_type*) const;
1126 private:
1127 // Original EXIDX input section.
1128 const Arm_exidx_input_section& exidx_input_section_;
1129 // Section offset map.
1130 const Arm_exidx_section_offset_map& section_offset_map_;
1133 // A class to wrap an ordinary input section containing executable code.
1135 template<bool big_endian>
1136 class Arm_input_section : public Output_relaxed_input_section
1138 public:
1139 Arm_input_section(Relobj* relobj, unsigned int shndx)
1140 : Output_relaxed_input_section(relobj, shndx, 1),
1141 original_addralign_(1), original_size_(0), stub_table_(NULL)
1144 ~Arm_input_section()
1147 // Initialize.
1148 void
1149 init();
1151 // Whether this is a stub table owner.
1152 bool
1153 is_stub_table_owner() const
1154 { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
1156 // Return the stub table.
1157 Stub_table<big_endian>*
1158 stub_table() const
1159 { return this->stub_table_; }
1161 // Set the stub_table.
1162 void
1163 set_stub_table(Stub_table<big_endian>* stub_table)
1164 { this->stub_table_ = stub_table; }
1166 // Downcast a base pointer to an Arm_input_section pointer. This is
1167 // not type-safe but we only use Arm_input_section not the base class.
1168 static Arm_input_section<big_endian>*
1169 as_arm_input_section(Output_relaxed_input_section* poris)
1170 { return static_cast<Arm_input_section<big_endian>*>(poris); }
1172 // Return the original size of the section.
1173 uint32_t
1174 original_size() const
1175 { return this->original_size_; }
1177 protected:
1178 // Write data to output file.
1179 void
1180 do_write(Output_file*);
1182 // Return required alignment of this.
1183 uint64_t
1184 do_addralign() const
1186 if (this->is_stub_table_owner())
1187 return std::max(this->stub_table_->addralign(),
1188 static_cast<uint64_t>(this->original_addralign_));
1189 else
1190 return this->original_addralign_;
1193 // Finalize data size.
1194 void
1195 set_final_data_size();
1197 // Reset address and file offset.
1198 void
1199 do_reset_address_and_file_offset();
1201 // Output offset.
1202 bool
1203 do_output_offset(const Relobj* object, unsigned int shndx,
1204 section_offset_type offset,
1205 section_offset_type* poutput) const
1207 if ((object == this->relobj())
1208 && (shndx == this->shndx())
1209 && (offset >= 0)
1210 && (offset <=
1211 convert_types<section_offset_type, uint32_t>(this->original_size_)))
1213 *poutput = offset;
1214 return true;
1216 else
1217 return false;
1220 private:
1221 // Copying is not allowed.
1222 Arm_input_section(const Arm_input_section&);
1223 Arm_input_section& operator=(const Arm_input_section&);
1225 // Address alignment of the original input section.
1226 uint32_t original_addralign_;
1227 // Section size of the original input section.
1228 uint32_t original_size_;
1229 // Stub table.
1230 Stub_table<big_endian>* stub_table_;
1233 // Arm_exidx_fixup class. This is used to define a number of methods
1234 // and keep states for fixing up EXIDX coverage.
1236 class Arm_exidx_fixup
1238 public:
1239 Arm_exidx_fixup(Output_section* exidx_output_section,
1240 bool merge_exidx_entries = true)
1241 : exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE),
1242 last_inlined_entry_(0), last_input_section_(NULL),
1243 section_offset_map_(NULL), first_output_text_section_(NULL),
1244 merge_exidx_entries_(merge_exidx_entries)
1247 ~Arm_exidx_fixup()
1248 { delete this->section_offset_map_; }
1250 // Process an EXIDX section for entry merging. Return number of bytes to
1251 // be deleted in output. If parts of the input EXIDX section are merged
1252 // a heap allocated Arm_exidx_section_offset_map is store in the located
1253 // PSECTION_OFFSET_MAP. The caller owns the map and is reponsible for
1254 // releasing it.
1255 template<bool big_endian>
1256 uint32_t
1257 process_exidx_section(const Arm_exidx_input_section* exidx_input_section,
1258 Arm_exidx_section_offset_map** psection_offset_map);
1260 // Append an EXIDX_CANTUNWIND entry pointing at the end of the last
1261 // input section, if there is not one already.
1262 void
1263 add_exidx_cantunwind_as_needed();
1265 // Return the output section for the text section which is linked to the
1266 // first exidx input in output.
1267 Output_section*
1268 first_output_text_section() const
1269 { return this->first_output_text_section_; }
1271 private:
1272 // Copying is not allowed.
1273 Arm_exidx_fixup(const Arm_exidx_fixup&);
1274 Arm_exidx_fixup& operator=(const Arm_exidx_fixup&);
1276 // Type of EXIDX unwind entry.
1277 enum Unwind_type
1279 // No type.
1280 UT_NONE,
1281 // EXIDX_CANTUNWIND.
1282 UT_EXIDX_CANTUNWIND,
1283 // Inlined entry.
1284 UT_INLINED_ENTRY,
1285 // Normal entry.
1286 UT_NORMAL_ENTRY,
1289 // Process an EXIDX entry. We only care about the second word of the
1290 // entry. Return true if the entry can be deleted.
1291 bool
1292 process_exidx_entry(uint32_t second_word);
1294 // Update the current section offset map during EXIDX section fix-up.
1295 // If there is no map, create one. INPUT_OFFSET is the offset of a
1296 // reference point, DELETED_BYTES is the number of deleted by in the
1297 // section so far. If DELETE_ENTRY is true, the reference point and
1298 // all offsets after the previous reference point are discarded.
1299 void
1300 update_offset_map(section_offset_type input_offset,
1301 section_size_type deleted_bytes, bool delete_entry);
1303 // EXIDX output section.
1304 Output_section* exidx_output_section_;
1305 // Unwind type of the last EXIDX entry processed.
1306 Unwind_type last_unwind_type_;
1307 // Last seen inlined EXIDX entry.
1308 uint32_t last_inlined_entry_;
1309 // Last processed EXIDX input section.
1310 const Arm_exidx_input_section* last_input_section_;
1311 // Section offset map created in process_exidx_section.
1312 Arm_exidx_section_offset_map* section_offset_map_;
1313 // Output section for the text section which is linked to the first exidx
1314 // input in output.
1315 Output_section* first_output_text_section_;
1317 bool merge_exidx_entries_;
1320 // Arm output section class. This is defined mainly to add a number of
1321 // stub generation methods.
1323 template<bool big_endian>
1324 class Arm_output_section : public Output_section
1326 public:
1327 typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list;
1329 Arm_output_section(const char* name, elfcpp::Elf_Word type,
1330 elfcpp::Elf_Xword flags)
1331 : Output_section(name, type, flags)
1333 if (type == elfcpp::SHT_ARM_EXIDX)
1334 this->set_always_keeps_input_sections();
1337 ~Arm_output_section()
1340 // Group input sections for stub generation.
1341 void
1342 group_sections(section_size_type, bool, Target_arm<big_endian>*);
1344 // Downcast a base pointer to an Arm_output_section pointer. This is
1345 // not type-safe but we only use Arm_output_section not the base class.
1346 static Arm_output_section<big_endian>*
1347 as_arm_output_section(Output_section* os)
1348 { return static_cast<Arm_output_section<big_endian>*>(os); }
1350 // Append all input text sections in this into LIST.
1351 void
1352 append_text_sections_to_list(Text_section_list* list);
1354 // Fix EXIDX coverage of this EXIDX output section. SORTED_TEXT_SECTION
1355 // is a list of text input sections sorted in ascending order of their
1356 // output addresses.
1357 void
1358 fix_exidx_coverage(Layout* layout,
1359 const Text_section_list& sorted_text_section,
1360 Symbol_table* symtab,
1361 bool merge_exidx_entries);
1363 // Link an EXIDX section into its corresponding text section.
1364 void
1365 set_exidx_section_link();
1367 private:
1368 // For convenience.
1369 typedef Output_section::Input_section Input_section;
1370 typedef Output_section::Input_section_list Input_section_list;
1372 // Create a stub group.
1373 void create_stub_group(Input_section_list::const_iterator,
1374 Input_section_list::const_iterator,
1375 Input_section_list::const_iterator,
1376 Target_arm<big_endian>*,
1377 std::vector<Output_relaxed_input_section*>*);
1380 // Arm_exidx_input_section class. This represents an EXIDX input section.
1382 class Arm_exidx_input_section
1384 public:
1385 static const section_offset_type invalid_offset =
1386 static_cast<section_offset_type>(-1);
1388 Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1389 unsigned int link, uint32_t size, uint32_t addralign)
1390 : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1391 addralign_(addralign), has_errors_(false)
1394 ~Arm_exidx_input_section()
1397 // Accessors: This is a read-only class.
1399 // Return the object containing this EXIDX input section.
1400 Relobj*
1401 relobj() const
1402 { return this->relobj_; }
1404 // Return the section index of this EXIDX input section.
1405 unsigned int
1406 shndx() const
1407 { return this->shndx_; }
1409 // Return the section index of linked text section in the same object.
1410 unsigned int
1411 link() const
1412 { return this->link_; }
1414 // Return size of the EXIDX input section.
1415 uint32_t
1416 size() const
1417 { return this->size_; }
1419 // Reutnr address alignment of EXIDX input section.
1420 uint32_t
1421 addralign() const
1422 { return this->addralign_; }
1424 // Whether there are any errors in the EXIDX input section.
1425 bool
1426 has_errors() const
1427 { return this->has_errors_; }
1429 // Set has-errors flag.
1430 void
1431 set_has_errors()
1432 { this->has_errors_ = true; }
1434 private:
1435 // Object containing this.
1436 Relobj* relobj_;
1437 // Section index of this.
1438 unsigned int shndx_;
1439 // text section linked to this in the same object.
1440 unsigned int link_;
1441 // Size of this. For ARM 32-bit is sufficient.
1442 uint32_t size_;
1443 // Address alignment of this. For ARM 32-bit is sufficient.
1444 uint32_t addralign_;
1445 // Whether this has any errors.
1446 bool has_errors_;
1449 // Arm_relobj class.
1451 template<bool big_endian>
1452 class Arm_relobj : public Sized_relobj<32, big_endian>
1454 public:
1455 static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1457 Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1458 const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1459 : Sized_relobj<32, big_endian>(name, input_file, offset, ehdr),
1460 stub_tables_(), local_symbol_is_thumb_function_(),
1461 attributes_section_data_(NULL), mapping_symbols_info_(),
1462 section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1463 output_local_symbol_count_needs_update_(false),
1464 merge_flags_and_attributes_(true)
1467 ~Arm_relobj()
1468 { delete this->attributes_section_data_; }
1470 // Return the stub table of the SHNDX-th section if there is one.
1471 Stub_table<big_endian>*
1472 stub_table(unsigned int shndx) const
1474 gold_assert(shndx < this->stub_tables_.size());
1475 return this->stub_tables_[shndx];
1478 // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1479 void
1480 set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1482 gold_assert(shndx < this->stub_tables_.size());
1483 this->stub_tables_[shndx] = stub_table;
1486 // Whether a local symbol is a THUMB function. R_SYM is the symbol table
1487 // index. This is only valid after do_count_local_symbol is called.
1488 bool
1489 local_symbol_is_thumb_function(unsigned int r_sym) const
1491 gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1492 return this->local_symbol_is_thumb_function_[r_sym];
1495 // Scan all relocation sections for stub generation.
1496 void
1497 scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1498 const Layout*);
1500 // Convert regular input section with index SHNDX to a relaxed section.
1501 void
1502 convert_input_section_to_relaxed_section(unsigned shndx)
1504 // The stubs have relocations and we need to process them after writing
1505 // out the stubs. So relocation now must follow section write.
1506 this->set_section_offset(shndx, -1ULL);
1507 this->set_relocs_must_follow_section_writes();
1510 // Downcast a base pointer to an Arm_relobj pointer. This is
1511 // not type-safe but we only use Arm_relobj not the base class.
1512 static Arm_relobj<big_endian>*
1513 as_arm_relobj(Relobj* relobj)
1514 { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1516 // Processor-specific flags in ELF file header. This is valid only after
1517 // reading symbols.
1518 elfcpp::Elf_Word
1519 processor_specific_flags() const
1520 { return this->processor_specific_flags_; }
1522 // Attribute section data This is the contents of the .ARM.attribute section
1523 // if there is one.
1524 const Attributes_section_data*
1525 attributes_section_data() const
1526 { return this->attributes_section_data_; }
1528 // Mapping symbol location.
1529 typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1531 // Functor for STL container.
1532 struct Mapping_symbol_position_less
1534 bool
1535 operator()(const Mapping_symbol_position& p1,
1536 const Mapping_symbol_position& p2) const
1538 return (p1.first < p2.first
1539 || (p1.first == p2.first && p1.second < p2.second));
1543 // We only care about the first character of a mapping symbol, so
1544 // we only store that instead of the whole symbol name.
1545 typedef std::map<Mapping_symbol_position, char,
1546 Mapping_symbol_position_less> Mapping_symbols_info;
1548 // Whether a section contains any Cortex-A8 workaround.
1549 bool
1550 section_has_cortex_a8_workaround(unsigned int shndx) const
1552 return (this->section_has_cortex_a8_workaround_ != NULL
1553 && (*this->section_has_cortex_a8_workaround_)[shndx]);
1556 // Mark a section that has Cortex-A8 workaround.
1557 void
1558 mark_section_for_cortex_a8_workaround(unsigned int shndx)
1560 if (this->section_has_cortex_a8_workaround_ == NULL)
1561 this->section_has_cortex_a8_workaround_ =
1562 new std::vector<bool>(this->shnum(), false);
1563 (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1566 // Return the EXIDX section of an text section with index SHNDX or NULL
1567 // if the text section has no associated EXIDX section.
1568 const Arm_exidx_input_section*
1569 exidx_input_section_by_link(unsigned int shndx) const
1571 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1572 return ((p != this->exidx_section_map_.end()
1573 && p->second->link() == shndx)
1574 ? p->second
1575 : NULL);
1578 // Return the EXIDX section with index SHNDX or NULL if there is none.
1579 const Arm_exidx_input_section*
1580 exidx_input_section_by_shndx(unsigned shndx) const
1582 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1583 return ((p != this->exidx_section_map_.end()
1584 && p->second->shndx() == shndx)
1585 ? p->second
1586 : NULL);
1589 // Whether output local symbol count needs updating.
1590 bool
1591 output_local_symbol_count_needs_update() const
1592 { return this->output_local_symbol_count_needs_update_; }
1594 // Set output_local_symbol_count_needs_update flag to be true.
1595 void
1596 set_output_local_symbol_count_needs_update()
1597 { this->output_local_symbol_count_needs_update_ = true; }
1599 // Update output local symbol count at the end of relaxation.
1600 void
1601 update_output_local_symbol_count();
1603 // Whether we want to merge processor-specific flags and attributes.
1604 bool
1605 merge_flags_and_attributes() const
1606 { return this->merge_flags_and_attributes_; }
1608 // Export list of EXIDX section indices.
1609 void
1610 get_exidx_shndx_list(std::vector<unsigned int>* list) const
1612 list->clear();
1613 for (Exidx_section_map::const_iterator p = this->exidx_section_map_.begin();
1614 p != this->exidx_section_map_.end();
1615 ++p)
1617 if (p->second->shndx() == p->first)
1618 list->push_back(p->first);
1620 // Sort list to make result independent of implementation of map.
1621 std::sort(list->begin(), list->end());
1624 protected:
1625 // Post constructor setup.
1626 void
1627 do_setup()
1629 // Call parent's setup method.
1630 Sized_relobj<32, big_endian>::do_setup();
1632 // Initialize look-up tables.
1633 Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1634 this->stub_tables_.swap(empty_stub_table_list);
1637 // Count the local symbols.
1638 void
1639 do_count_local_symbols(Stringpool_template<char>*,
1640 Stringpool_template<char>*);
1642 void
1643 do_relocate_sections(const Symbol_table* symtab, const Layout* layout,
1644 const unsigned char* pshdrs, Output_file* of,
1645 typename Sized_relobj<32, big_endian>::Views* pivews);
1647 // Read the symbol information.
1648 void
1649 do_read_symbols(Read_symbols_data* sd);
1651 // Process relocs for garbage collection.
1652 void
1653 do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1655 private:
1657 // Whether a section needs to be scanned for relocation stubs.
1658 bool
1659 section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1660 const Relobj::Output_sections&,
1661 const Symbol_table*, const unsigned char*);
1663 // Whether a section is a scannable text section.
1664 bool
1665 section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1666 const Output_section*, const Symbol_table*);
1668 // Whether a section needs to be scanned for the Cortex-A8 erratum.
1669 bool
1670 section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1671 unsigned int, Output_section*,
1672 const Symbol_table*);
1674 // Scan a section for the Cortex-A8 erratum.
1675 void
1676 scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1677 unsigned int, Output_section*,
1678 Target_arm<big_endian>*);
1680 // Find the linked text section of an EXIDX section by looking at the
1681 // first reloction of the EXIDX section. PSHDR points to the section
1682 // headers of a relocation section and PSYMS points to the local symbols.
1683 // PSHNDX points to a location storing the text section index if found.
1684 // Return whether we can find the linked section.
1685 bool
1686 find_linked_text_section(const unsigned char* pshdr,
1687 const unsigned char* psyms, unsigned int* pshndx);
1690 // Make a new Arm_exidx_input_section object for EXIDX section with
1691 // index SHNDX and section header SHDR. TEXT_SHNDX is the section
1692 // index of the linked text section.
1693 void
1694 make_exidx_input_section(unsigned int shndx,
1695 const elfcpp::Shdr<32, big_endian>& shdr,
1696 unsigned int text_shndx,
1697 const elfcpp::Shdr<32, big_endian>& text_shdr);
1699 // Return the output address of either a plain input section or a
1700 // relaxed input section. SHNDX is the section index.
1701 Arm_address
1702 simple_input_section_output_address(unsigned int, Output_section*);
1704 typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1705 typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1706 Exidx_section_map;
1708 // List of stub tables.
1709 Stub_table_list stub_tables_;
1710 // Bit vector to tell if a local symbol is a thumb function or not.
1711 // This is only valid after do_count_local_symbol is called.
1712 std::vector<bool> local_symbol_is_thumb_function_;
1713 // processor-specific flags in ELF file header.
1714 elfcpp::Elf_Word processor_specific_flags_;
1715 // Object attributes if there is an .ARM.attributes section or NULL.
1716 Attributes_section_data* attributes_section_data_;
1717 // Mapping symbols information.
1718 Mapping_symbols_info mapping_symbols_info_;
1719 // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1720 std::vector<bool>* section_has_cortex_a8_workaround_;
1721 // Map a text section to its associated .ARM.exidx section, if there is one.
1722 Exidx_section_map exidx_section_map_;
1723 // Whether output local symbol count needs updating.
1724 bool output_local_symbol_count_needs_update_;
1725 // Whether we merge processor flags and attributes of this object to
1726 // output.
1727 bool merge_flags_and_attributes_;
1730 // Arm_dynobj class.
1732 template<bool big_endian>
1733 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1735 public:
1736 Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1737 const elfcpp::Ehdr<32, big_endian>& ehdr)
1738 : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1739 processor_specific_flags_(0), attributes_section_data_(NULL)
1742 ~Arm_dynobj()
1743 { delete this->attributes_section_data_; }
1745 // Downcast a base pointer to an Arm_relobj pointer. This is
1746 // not type-safe but we only use Arm_relobj not the base class.
1747 static Arm_dynobj<big_endian>*
1748 as_arm_dynobj(Dynobj* dynobj)
1749 { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1751 // Processor-specific flags in ELF file header. This is valid only after
1752 // reading symbols.
1753 elfcpp::Elf_Word
1754 processor_specific_flags() const
1755 { return this->processor_specific_flags_; }
1757 // Attributes section data.
1758 const Attributes_section_data*
1759 attributes_section_data() const
1760 { return this->attributes_section_data_; }
1762 protected:
1763 // Read the symbol information.
1764 void
1765 do_read_symbols(Read_symbols_data* sd);
1767 private:
1768 // processor-specific flags in ELF file header.
1769 elfcpp::Elf_Word processor_specific_flags_;
1770 // Object attributes if there is an .ARM.attributes section or NULL.
1771 Attributes_section_data* attributes_section_data_;
1774 // Functor to read reloc addends during stub generation.
1776 template<int sh_type, bool big_endian>
1777 struct Stub_addend_reader
1779 // Return the addend for a relocation of a particular type. Depending
1780 // on whether this is a REL or RELA relocation, read the addend from a
1781 // view or from a Reloc object.
1782 elfcpp::Elf_types<32>::Elf_Swxword
1783 operator()(
1784 unsigned int /* r_type */,
1785 const unsigned char* /* view */,
1786 const typename Reloc_types<sh_type,
1787 32, big_endian>::Reloc& /* reloc */) const;
1790 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1792 template<bool big_endian>
1793 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1795 elfcpp::Elf_types<32>::Elf_Swxword
1796 operator()(
1797 unsigned int,
1798 const unsigned char*,
1799 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1802 // Specialized Stub_addend_reader for RELA type relocation sections.
1803 // We currently do not handle RELA type relocation sections but it is trivial
1804 // to implement the addend reader. This is provided for completeness and to
1805 // make it easier to add support for RELA relocation sections in the future.
1807 template<bool big_endian>
1808 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1810 elfcpp::Elf_types<32>::Elf_Swxword
1811 operator()(
1812 unsigned int,
1813 const unsigned char*,
1814 const typename Reloc_types<elfcpp::SHT_RELA, 32,
1815 big_endian>::Reloc& reloc) const
1816 { return reloc.get_r_addend(); }
1819 // Cortex_a8_reloc class. We keep record of relocation that may need
1820 // the Cortex-A8 erratum workaround.
1822 class Cortex_a8_reloc
1824 public:
1825 Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1826 Arm_address destination)
1827 : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1830 ~Cortex_a8_reloc()
1833 // Accessors: This is a read-only class.
1835 // Return the relocation stub associated with this relocation if there is
1836 // one.
1837 const Reloc_stub*
1838 reloc_stub() const
1839 { return this->reloc_stub_; }
1841 // Return the relocation type.
1842 unsigned int
1843 r_type() const
1844 { return this->r_type_; }
1846 // Return the destination address of the relocation. LSB stores the THUMB
1847 // bit.
1848 Arm_address
1849 destination() const
1850 { return this->destination_; }
1852 private:
1853 // Associated relocation stub if there is one, or NULL.
1854 const Reloc_stub* reloc_stub_;
1855 // Relocation type.
1856 unsigned int r_type_;
1857 // Destination address of this relocation. LSB is used to distinguish
1858 // ARM/THUMB mode.
1859 Arm_address destination_;
1862 // Arm_output_data_got class. We derive this from Output_data_got to add
1863 // extra methods to handle TLS relocations in a static link.
1865 template<bool big_endian>
1866 class Arm_output_data_got : public Output_data_got<32, big_endian>
1868 public:
1869 Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1870 : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1873 // Add a static entry for the GOT entry at OFFSET. GSYM is a global
1874 // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1875 // applied in a static link.
1876 void
1877 add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1878 { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1880 // Add a static reloc for the GOT entry at OFFSET. RELOBJ is an object
1881 // defining a local symbol with INDEX. R_TYPE is the code of a dynamic
1882 // relocation that needs to be applied in a static link.
1883 void
1884 add_static_reloc(unsigned int got_offset, unsigned int r_type,
1885 Sized_relobj<32, big_endian>* relobj, unsigned int index)
1887 this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1888 index));
1891 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
1892 // The first one is initialized to be 1, which is the module index for
1893 // the main executable and the second one 0. A reloc of the type
1894 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1895 // be applied by gold. GSYM is a global symbol.
1896 void
1897 add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1899 // Same as the above but for a local symbol in OBJECT with INDEX.
1900 void
1901 add_tls_gd32_with_static_reloc(unsigned int got_type,
1902 Sized_relobj<32, big_endian>* object,
1903 unsigned int index);
1905 protected:
1906 // Write out the GOT table.
1907 void
1908 do_write(Output_file*);
1910 private:
1911 // This class represent dynamic relocations that need to be applied by
1912 // gold because we are using TLS relocations in a static link.
1913 class Static_reloc
1915 public:
1916 Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1917 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1918 { this->u_.global.symbol = gsym; }
1920 Static_reloc(unsigned int got_offset, unsigned int r_type,
1921 Sized_relobj<32, big_endian>* relobj, unsigned int index)
1922 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1924 this->u_.local.relobj = relobj;
1925 this->u_.local.index = index;
1928 // Return the GOT offset.
1929 unsigned int
1930 got_offset() const
1931 { return this->got_offset_; }
1933 // Relocation type.
1934 unsigned int
1935 r_type() const
1936 { return this->r_type_; }
1938 // Whether the symbol is global or not.
1939 bool
1940 symbol_is_global() const
1941 { return this->symbol_is_global_; }
1943 // For a relocation against a global symbol, the global symbol.
1944 Symbol*
1945 symbol() const
1947 gold_assert(this->symbol_is_global_);
1948 return this->u_.global.symbol;
1951 // For a relocation against a local symbol, the defining object.
1952 Sized_relobj<32, big_endian>*
1953 relobj() const
1955 gold_assert(!this->symbol_is_global_);
1956 return this->u_.local.relobj;
1959 // For a relocation against a local symbol, the local symbol index.
1960 unsigned int
1961 index() const
1963 gold_assert(!this->symbol_is_global_);
1964 return this->u_.local.index;
1967 private:
1968 // GOT offset of the entry to which this relocation is applied.
1969 unsigned int got_offset_;
1970 // Type of relocation.
1971 unsigned int r_type_;
1972 // Whether this relocation is against a global symbol.
1973 bool symbol_is_global_;
1974 // A global or local symbol.
1975 union
1977 struct
1979 // For a global symbol, the symbol itself.
1980 Symbol* symbol;
1981 } global;
1982 struct
1984 // For a local symbol, the object defining object.
1985 Sized_relobj<32, big_endian>* relobj;
1986 // For a local symbol, the symbol index.
1987 unsigned int index;
1988 } local;
1989 } u_;
1992 // Symbol table of the output object.
1993 Symbol_table* symbol_table_;
1994 // Layout of the output object.
1995 Layout* layout_;
1996 // Static relocs to be applied to the GOT.
1997 std::vector<Static_reloc> static_relocs_;
2000 // The ARM target has many relocation types with odd-sizes or incontigious
2001 // bits. The default handling of relocatable relocation cannot process these
2002 // relocations. So we have to extend the default code.
2004 template<bool big_endian, int sh_type, typename Classify_reloc>
2005 class Arm_scan_relocatable_relocs :
2006 public Default_scan_relocatable_relocs<sh_type, Classify_reloc>
2008 public:
2009 // Return the strategy to use for a local symbol which is a section
2010 // symbol, given the relocation type.
2011 inline Relocatable_relocs::Reloc_strategy
2012 local_section_strategy(unsigned int r_type, Relobj*)
2014 if (sh_type == elfcpp::SHT_RELA)
2015 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
2016 else
2018 if (r_type == elfcpp::R_ARM_TARGET1
2019 || r_type == elfcpp::R_ARM_TARGET2)
2021 const Target_arm<big_endian>* arm_target =
2022 Target_arm<big_endian>::default_target();
2023 r_type = arm_target->get_real_reloc_type(r_type);
2026 switch(r_type)
2028 // Relocations that write nothing. These exclude R_ARM_TARGET1
2029 // and R_ARM_TARGET2.
2030 case elfcpp::R_ARM_NONE:
2031 case elfcpp::R_ARM_V4BX:
2032 case elfcpp::R_ARM_TLS_GOTDESC:
2033 case elfcpp::R_ARM_TLS_CALL:
2034 case elfcpp::R_ARM_TLS_DESCSEQ:
2035 case elfcpp::R_ARM_THM_TLS_CALL:
2036 case elfcpp::R_ARM_GOTRELAX:
2037 case elfcpp::R_ARM_GNU_VTENTRY:
2038 case elfcpp::R_ARM_GNU_VTINHERIT:
2039 case elfcpp::R_ARM_THM_TLS_DESCSEQ16:
2040 case elfcpp::R_ARM_THM_TLS_DESCSEQ32:
2041 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
2042 // These should have been converted to something else above.
2043 case elfcpp::R_ARM_TARGET1:
2044 case elfcpp::R_ARM_TARGET2:
2045 gold_unreachable();
2046 // Relocations that write full 32 bits.
2047 case elfcpp::R_ARM_ABS32:
2048 case elfcpp::R_ARM_REL32:
2049 case elfcpp::R_ARM_SBREL32:
2050 case elfcpp::R_ARM_GOTOFF32:
2051 case elfcpp::R_ARM_BASE_PREL:
2052 case elfcpp::R_ARM_GOT_BREL:
2053 case elfcpp::R_ARM_BASE_ABS:
2054 case elfcpp::R_ARM_ABS32_NOI:
2055 case elfcpp::R_ARM_REL32_NOI:
2056 case elfcpp::R_ARM_PLT32_ABS:
2057 case elfcpp::R_ARM_GOT_ABS:
2058 case elfcpp::R_ARM_GOT_PREL:
2059 case elfcpp::R_ARM_TLS_GD32:
2060 case elfcpp::R_ARM_TLS_LDM32:
2061 case elfcpp::R_ARM_TLS_LDO32:
2062 case elfcpp::R_ARM_TLS_IE32:
2063 case elfcpp::R_ARM_TLS_LE32:
2064 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4;
2065 default:
2066 // For all other static relocations, return RELOC_SPECIAL.
2067 return Relocatable_relocs::RELOC_SPECIAL;
2073 // Utilities for manipulating integers of up to 32-bits
2075 namespace utils
2077 // Sign extend an n-bit unsigned integer stored in an uint32_t into
2078 // an int32_t. NO_BITS must be between 1 to 32.
2079 template<int no_bits>
2080 static inline int32_t
2081 sign_extend(uint32_t bits)
2083 gold_assert(no_bits >= 0 && no_bits <= 32);
2084 if (no_bits == 32)
2085 return static_cast<int32_t>(bits);
2086 uint32_t mask = (~((uint32_t) 0)) >> (32 - no_bits);
2087 bits &= mask;
2088 uint32_t top_bit = 1U << (no_bits - 1);
2089 int32_t as_signed = static_cast<int32_t>(bits);
2090 return (bits & top_bit) ? as_signed + (-top_bit * 2) : as_signed;
2093 // Detects overflow of an NO_BITS integer stored in a uint32_t.
2094 template<int no_bits>
2095 static inline bool
2096 has_overflow(uint32_t bits)
2098 gold_assert(no_bits >= 0 && no_bits <= 32);
2099 if (no_bits == 32)
2100 return false;
2101 int32_t max = (1 << (no_bits - 1)) - 1;
2102 int32_t min = -(1 << (no_bits - 1));
2103 int32_t as_signed = static_cast<int32_t>(bits);
2104 return as_signed > max || as_signed < min;
2107 // Detects overflow of an NO_BITS integer stored in a uint32_t when it
2108 // fits in the given number of bits as either a signed or unsigned value.
2109 // For example, has_signed_unsigned_overflow<8> would check
2110 // -128 <= bits <= 255
2111 template<int no_bits>
2112 static inline bool
2113 has_signed_unsigned_overflow(uint32_t bits)
2115 gold_assert(no_bits >= 2 && no_bits <= 32);
2116 if (no_bits == 32)
2117 return false;
2118 int32_t max = static_cast<int32_t>((1U << no_bits) - 1);
2119 int32_t min = -(1 << (no_bits - 1));
2120 int32_t as_signed = static_cast<int32_t>(bits);
2121 return as_signed > max || as_signed < min;
2124 // Select bits from A and B using bits in MASK. For each n in [0..31],
2125 // the n-th bit in the result is chosen from the n-th bits of A and B.
2126 // A zero selects A and a one selects B.
2127 static inline uint32_t
2128 bit_select(uint32_t a, uint32_t b, uint32_t mask)
2129 { return (a & ~mask) | (b & mask); }
2132 template<bool big_endian>
2133 class Target_arm : public Sized_target<32, big_endian>
2135 public:
2136 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
2137 Reloc_section;
2139 // When were are relocating a stub, we pass this as the relocation number.
2140 static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
2142 Target_arm()
2143 : Sized_target<32, big_endian>(&arm_info),
2144 got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
2145 copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL),
2146 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2147 stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2148 may_use_blx_(false), should_force_pic_veneer_(false),
2149 arm_input_section_map_(), attributes_section_data_(NULL),
2150 fix_cortex_a8_(false), cortex_a8_relocs_info_()
2153 // Virtual function which is set to return true by a target if
2154 // it can use relocation types to determine if a function's
2155 // pointer is taken.
2156 virtual bool
2157 can_check_for_function_pointers() const
2158 { return true; }
2160 // Whether a section called SECTION_NAME may have function pointers to
2161 // sections not eligible for safe ICF folding.
2162 virtual bool
2163 section_may_have_icf_unsafe_pointers(const char* section_name) const
2165 return (!is_prefix_of(".ARM.exidx", section_name)
2166 && !is_prefix_of(".ARM.extab", section_name)
2167 && Target::section_may_have_icf_unsafe_pointers(section_name));
2170 // Whether we can use BLX.
2171 bool
2172 may_use_blx() const
2173 { return this->may_use_blx_; }
2175 // Set use-BLX flag.
2176 void
2177 set_may_use_blx(bool value)
2178 { this->may_use_blx_ = value; }
2180 // Whether we force PCI branch veneers.
2181 bool
2182 should_force_pic_veneer() const
2183 { return this->should_force_pic_veneer_; }
2185 // Set PIC veneer flag.
2186 void
2187 set_should_force_pic_veneer(bool value)
2188 { this->should_force_pic_veneer_ = value; }
2190 // Whether we use THUMB-2 instructions.
2191 bool
2192 using_thumb2() const
2194 Object_attribute* attr =
2195 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2196 int arch = attr->int_value();
2197 return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2200 // Whether we use THUMB/THUMB-2 instructions only.
2201 bool
2202 using_thumb_only() const
2204 Object_attribute* attr =
2205 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2207 if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M
2208 || attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M)
2209 return true;
2210 if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2211 && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2212 return false;
2213 attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2214 return attr->int_value() == 'M';
2217 // Whether we have an NOP instruction. If not, use mov r0, r0 instead.
2218 bool
2219 may_use_arm_nop() const
2221 Object_attribute* attr =
2222 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2223 int arch = attr->int_value();
2224 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2225 || arch == elfcpp::TAG_CPU_ARCH_V6K
2226 || arch == elfcpp::TAG_CPU_ARCH_V7
2227 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2230 // Whether we have THUMB-2 NOP.W instruction.
2231 bool
2232 may_use_thumb2_nop() const
2234 Object_attribute* attr =
2235 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2236 int arch = attr->int_value();
2237 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2238 || arch == elfcpp::TAG_CPU_ARCH_V7
2239 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2242 // Process the relocations to determine unreferenced sections for
2243 // garbage collection.
2244 void
2245 gc_process_relocs(Symbol_table* symtab,
2246 Layout* layout,
2247 Sized_relobj<32, big_endian>* object,
2248 unsigned int data_shndx,
2249 unsigned int sh_type,
2250 const unsigned char* prelocs,
2251 size_t reloc_count,
2252 Output_section* output_section,
2253 bool needs_special_offset_handling,
2254 size_t local_symbol_count,
2255 const unsigned char* plocal_symbols);
2257 // Scan the relocations to look for symbol adjustments.
2258 void
2259 scan_relocs(Symbol_table* symtab,
2260 Layout* layout,
2261 Sized_relobj<32, big_endian>* object,
2262 unsigned int data_shndx,
2263 unsigned int sh_type,
2264 const unsigned char* prelocs,
2265 size_t reloc_count,
2266 Output_section* output_section,
2267 bool needs_special_offset_handling,
2268 size_t local_symbol_count,
2269 const unsigned char* plocal_symbols);
2271 // Finalize the sections.
2272 void
2273 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2275 // Return the value to use for a dynamic symbol which requires special
2276 // treatment.
2277 uint64_t
2278 do_dynsym_value(const Symbol*) const;
2280 // Relocate a section.
2281 void
2282 relocate_section(const Relocate_info<32, big_endian>*,
2283 unsigned int sh_type,
2284 const unsigned char* prelocs,
2285 size_t reloc_count,
2286 Output_section* output_section,
2287 bool needs_special_offset_handling,
2288 unsigned char* view,
2289 Arm_address view_address,
2290 section_size_type view_size,
2291 const Reloc_symbol_changes*);
2293 // Scan the relocs during a relocatable link.
2294 void
2295 scan_relocatable_relocs(Symbol_table* symtab,
2296 Layout* layout,
2297 Sized_relobj<32, big_endian>* object,
2298 unsigned int data_shndx,
2299 unsigned int sh_type,
2300 const unsigned char* prelocs,
2301 size_t reloc_count,
2302 Output_section* output_section,
2303 bool needs_special_offset_handling,
2304 size_t local_symbol_count,
2305 const unsigned char* plocal_symbols,
2306 Relocatable_relocs*);
2308 // Relocate a section during a relocatable link.
2309 void
2310 relocate_for_relocatable(const Relocate_info<32, big_endian>*,
2311 unsigned int sh_type,
2312 const unsigned char* prelocs,
2313 size_t reloc_count,
2314 Output_section* output_section,
2315 off_t offset_in_output_section,
2316 const Relocatable_relocs*,
2317 unsigned char* view,
2318 Arm_address view_address,
2319 section_size_type view_size,
2320 unsigned char* reloc_view,
2321 section_size_type reloc_view_size);
2323 // Perform target-specific processing in a relocatable link. This is
2324 // only used if we use the relocation strategy RELOC_SPECIAL.
2325 void
2326 relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2327 unsigned int sh_type,
2328 const unsigned char* preloc_in,
2329 size_t relnum,
2330 Output_section* output_section,
2331 off_t offset_in_output_section,
2332 unsigned char* view,
2333 typename elfcpp::Elf_types<32>::Elf_Addr
2334 view_address,
2335 section_size_type view_size,
2336 unsigned char* preloc_out);
2338 // Return whether SYM is defined by the ABI.
2339 bool
2340 do_is_defined_by_abi(Symbol* sym) const
2341 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2343 // Return whether there is a GOT section.
2344 bool
2345 has_got_section() const
2346 { return this->got_ != NULL; }
2348 // Return the size of the GOT section.
2349 section_size_type
2350 got_size() const
2352 gold_assert(this->got_ != NULL);
2353 return this->got_->data_size();
2356 // Return the number of entries in the GOT.
2357 unsigned int
2358 got_entry_count() const
2360 if (!this->has_got_section())
2361 return 0;
2362 return this->got_size() / 4;
2365 // Return the number of entries in the PLT.
2366 unsigned int
2367 plt_entry_count() const;
2369 // Return the offset of the first non-reserved PLT entry.
2370 unsigned int
2371 first_plt_entry_offset() const;
2373 // Return the size of each PLT entry.
2374 unsigned int
2375 plt_entry_size() const;
2377 // Map platform-specific reloc types
2378 static unsigned int
2379 get_real_reloc_type(unsigned int r_type);
2382 // Methods to support stub-generations.
2385 // Return the stub factory
2386 const Stub_factory&
2387 stub_factory() const
2388 { return this->stub_factory_; }
2390 // Make a new Arm_input_section object.
2391 Arm_input_section<big_endian>*
2392 new_arm_input_section(Relobj*, unsigned int);
2394 // Find the Arm_input_section object corresponding to the SHNDX-th input
2395 // section of RELOBJ.
2396 Arm_input_section<big_endian>*
2397 find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2399 // Make a new Stub_table
2400 Stub_table<big_endian>*
2401 new_stub_table(Arm_input_section<big_endian>*);
2403 // Scan a section for stub generation.
2404 void
2405 scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2406 const unsigned char*, size_t, Output_section*,
2407 bool, const unsigned char*, Arm_address,
2408 section_size_type);
2410 // Relocate a stub.
2411 void
2412 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2413 Output_section*, unsigned char*, Arm_address,
2414 section_size_type);
2416 // Get the default ARM target.
2417 static Target_arm<big_endian>*
2418 default_target()
2420 gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2421 && parameters->target().is_big_endian() == big_endian);
2422 return static_cast<Target_arm<big_endian>*>(
2423 parameters->sized_target<32, big_endian>());
2426 // Whether NAME belongs to a mapping symbol.
2427 static bool
2428 is_mapping_symbol_name(const char* name)
2430 return (name
2431 && name[0] == '$'
2432 && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2433 && (name[2] == '\0' || name[2] == '.'));
2436 // Whether we work around the Cortex-A8 erratum.
2437 bool
2438 fix_cortex_a8() const
2439 { return this->fix_cortex_a8_; }
2441 // Whether we merge exidx entries in debuginfo.
2442 bool
2443 merge_exidx_entries() const
2444 { return parameters->options().merge_exidx_entries(); }
2446 // Whether we fix R_ARM_V4BX relocation.
2447 // 0 - do not fix
2448 // 1 - replace with MOV instruction (armv4 target)
2449 // 2 - make interworking veneer (>= armv4t targets only)
2450 General_options::Fix_v4bx
2451 fix_v4bx() const
2452 { return parameters->options().fix_v4bx(); }
2454 // Scan a span of THUMB code section for Cortex-A8 erratum.
2455 void
2456 scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2457 section_size_type, section_size_type,
2458 const unsigned char*, Arm_address);
2460 // Apply Cortex-A8 workaround to a branch.
2461 void
2462 apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2463 unsigned char*, Arm_address);
2465 protected:
2466 // Make an ELF object.
2467 Object*
2468 do_make_elf_object(const std::string&, Input_file*, off_t,
2469 const elfcpp::Ehdr<32, big_endian>& ehdr);
2471 Object*
2472 do_make_elf_object(const std::string&, Input_file*, off_t,
2473 const elfcpp::Ehdr<32, !big_endian>&)
2474 { gold_unreachable(); }
2476 Object*
2477 do_make_elf_object(const std::string&, Input_file*, off_t,
2478 const elfcpp::Ehdr<64, false>&)
2479 { gold_unreachable(); }
2481 Object*
2482 do_make_elf_object(const std::string&, Input_file*, off_t,
2483 const elfcpp::Ehdr<64, true>&)
2484 { gold_unreachable(); }
2486 // Make an output section.
2487 Output_section*
2488 do_make_output_section(const char* name, elfcpp::Elf_Word type,
2489 elfcpp::Elf_Xword flags)
2490 { return new Arm_output_section<big_endian>(name, type, flags); }
2492 void
2493 do_adjust_elf_header(unsigned char* view, int len) const;
2495 // We only need to generate stubs, and hence perform relaxation if we are
2496 // not doing relocatable linking.
2497 bool
2498 do_may_relax() const
2499 { return !parameters->options().relocatable(); }
2501 bool
2502 do_relax(int, const Input_objects*, Symbol_table*, Layout*);
2504 // Determine whether an object attribute tag takes an integer, a
2505 // string or both.
2507 do_attribute_arg_type(int tag) const;
2509 // Reorder tags during output.
2511 do_attributes_order(int num) const;
2513 // This is called when the target is selected as the default.
2514 void
2515 do_select_as_default_target()
2517 // No locking is required since there should only be one default target.
2518 // We cannot have both the big-endian and little-endian ARM targets
2519 // as the default.
2520 gold_assert(arm_reloc_property_table == NULL);
2521 arm_reloc_property_table = new Arm_reloc_property_table();
2524 private:
2525 // The class which scans relocations.
2526 class Scan
2528 public:
2529 Scan()
2530 : issued_non_pic_error_(false)
2533 inline void
2534 local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2535 Sized_relobj<32, big_endian>* object,
2536 unsigned int data_shndx,
2537 Output_section* output_section,
2538 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2539 const elfcpp::Sym<32, big_endian>& lsym);
2541 inline void
2542 global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2543 Sized_relobj<32, big_endian>* object,
2544 unsigned int data_shndx,
2545 Output_section* output_section,
2546 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2547 Symbol* gsym);
2549 inline bool
2550 local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2551 Sized_relobj<32, big_endian>* ,
2552 unsigned int ,
2553 Output_section* ,
2554 const elfcpp::Rel<32, big_endian>& ,
2555 unsigned int ,
2556 const elfcpp::Sym<32, big_endian>&);
2558 inline bool
2559 global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2560 Sized_relobj<32, big_endian>* ,
2561 unsigned int ,
2562 Output_section* ,
2563 const elfcpp::Rel<32, big_endian>& ,
2564 unsigned int , Symbol*);
2566 private:
2567 static void
2568 unsupported_reloc_local(Sized_relobj<32, big_endian>*,
2569 unsigned int r_type);
2571 static void
2572 unsupported_reloc_global(Sized_relobj<32, big_endian>*,
2573 unsigned int r_type, Symbol*);
2575 void
2576 check_non_pic(Relobj*, unsigned int r_type);
2578 // Almost identical to Symbol::needs_plt_entry except that it also
2579 // handles STT_ARM_TFUNC.
2580 static bool
2581 symbol_needs_plt_entry(const Symbol* sym)
2583 // An undefined symbol from an executable does not need a PLT entry.
2584 if (sym->is_undefined() && !parameters->options().shared())
2585 return false;
2587 return (!parameters->doing_static_link()
2588 && (sym->type() == elfcpp::STT_FUNC
2589 || sym->type() == elfcpp::STT_ARM_TFUNC)
2590 && (sym->is_from_dynobj()
2591 || sym->is_undefined()
2592 || sym->is_preemptible()));
2595 inline bool
2596 possible_function_pointer_reloc(unsigned int r_type);
2598 // Whether we have issued an error about a non-PIC compilation.
2599 bool issued_non_pic_error_;
2602 // The class which implements relocation.
2603 class Relocate
2605 public:
2606 Relocate()
2609 ~Relocate()
2612 // Return whether the static relocation needs to be applied.
2613 inline bool
2614 should_apply_static_reloc(const Sized_symbol<32>* gsym,
2615 int ref_flags,
2616 bool is_32bit,
2617 Output_section* output_section);
2619 // Do a relocation. Return false if the caller should not issue
2620 // any warnings about this relocation.
2621 inline bool
2622 relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2623 Output_section*, size_t relnum,
2624 const elfcpp::Rel<32, big_endian>&,
2625 unsigned int r_type, const Sized_symbol<32>*,
2626 const Symbol_value<32>*,
2627 unsigned char*, Arm_address,
2628 section_size_type);
2630 // Return whether we want to pass flag NON_PIC_REF for this
2631 // reloc. This means the relocation type accesses a symbol not via
2632 // GOT or PLT.
2633 static inline bool
2634 reloc_is_non_pic(unsigned int r_type)
2636 switch (r_type)
2638 // These relocation types reference GOT or PLT entries explicitly.
2639 case elfcpp::R_ARM_GOT_BREL:
2640 case elfcpp::R_ARM_GOT_ABS:
2641 case elfcpp::R_ARM_GOT_PREL:
2642 case elfcpp::R_ARM_GOT_BREL12:
2643 case elfcpp::R_ARM_PLT32_ABS:
2644 case elfcpp::R_ARM_TLS_GD32:
2645 case elfcpp::R_ARM_TLS_LDM32:
2646 case elfcpp::R_ARM_TLS_IE32:
2647 case elfcpp::R_ARM_TLS_IE12GP:
2649 // These relocate types may use PLT entries.
2650 case elfcpp::R_ARM_CALL:
2651 case elfcpp::R_ARM_THM_CALL:
2652 case elfcpp::R_ARM_JUMP24:
2653 case elfcpp::R_ARM_THM_JUMP24:
2654 case elfcpp::R_ARM_THM_JUMP19:
2655 case elfcpp::R_ARM_PLT32:
2656 case elfcpp::R_ARM_THM_XPC22:
2657 case elfcpp::R_ARM_PREL31:
2658 case elfcpp::R_ARM_SBREL31:
2659 return false;
2661 default:
2662 return true;
2666 private:
2667 // Do a TLS relocation.
2668 inline typename Arm_relocate_functions<big_endian>::Status
2669 relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2670 size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2671 const Sized_symbol<32>*, const Symbol_value<32>*,
2672 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2673 section_size_type);
2677 // A class which returns the size required for a relocation type,
2678 // used while scanning relocs during a relocatable link.
2679 class Relocatable_size_for_reloc
2681 public:
2682 unsigned int
2683 get_size_for_reloc(unsigned int, Relobj*);
2686 // Adjust TLS relocation type based on the options and whether this
2687 // is a local symbol.
2688 static tls::Tls_optimization
2689 optimize_tls_reloc(bool is_final, int r_type);
2691 // Get the GOT section, creating it if necessary.
2692 Arm_output_data_got<big_endian>*
2693 got_section(Symbol_table*, Layout*);
2695 // Get the GOT PLT section.
2696 Output_data_space*
2697 got_plt_section() const
2699 gold_assert(this->got_plt_ != NULL);
2700 return this->got_plt_;
2703 // Create a PLT entry for a global symbol.
2704 void
2705 make_plt_entry(Symbol_table*, Layout*, Symbol*);
2707 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2708 void
2709 define_tls_base_symbol(Symbol_table*, Layout*);
2711 // Create a GOT entry for the TLS module index.
2712 unsigned int
2713 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2714 Sized_relobj<32, big_endian>* object);
2716 // Get the PLT section.
2717 const Output_data_plt_arm<big_endian>*
2718 plt_section() const
2720 gold_assert(this->plt_ != NULL);
2721 return this->plt_;
2724 // Get the dynamic reloc section, creating it if necessary.
2725 Reloc_section*
2726 rel_dyn_section(Layout*);
2728 // Get the section to use for TLS_DESC relocations.
2729 Reloc_section*
2730 rel_tls_desc_section(Layout*) const;
2732 // Return true if the symbol may need a COPY relocation.
2733 // References from an executable object to non-function symbols
2734 // defined in a dynamic object may need a COPY relocation.
2735 bool
2736 may_need_copy_reloc(Symbol* gsym)
2738 return (gsym->type() != elfcpp::STT_ARM_TFUNC
2739 && gsym->may_need_copy_reloc());
2742 // Add a potential copy relocation.
2743 void
2744 copy_reloc(Symbol_table* symtab, Layout* layout,
2745 Sized_relobj<32, big_endian>* object,
2746 unsigned int shndx, Output_section* output_section,
2747 Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2749 this->copy_relocs_.copy_reloc(symtab, layout,
2750 symtab->get_sized_symbol<32>(sym),
2751 object, shndx, output_section, reloc,
2752 this->rel_dyn_section(layout));
2755 // Whether two EABI versions are compatible.
2756 static bool
2757 are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2759 // Merge processor-specific flags from input object and those in the ELF
2760 // header of the output.
2761 void
2762 merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2764 // Get the secondary compatible architecture.
2765 static int
2766 get_secondary_compatible_arch(const Attributes_section_data*);
2768 // Set the secondary compatible architecture.
2769 static void
2770 set_secondary_compatible_arch(Attributes_section_data*, int);
2772 static int
2773 tag_cpu_arch_combine(const char*, int, int*, int, int);
2775 // Helper to print AEABI enum tag value.
2776 static std::string
2777 aeabi_enum_name(unsigned int);
2779 // Return string value for TAG_CPU_name.
2780 static std::string
2781 tag_cpu_name_value(unsigned int);
2783 // Merge object attributes from input object and those in the output.
2784 void
2785 merge_object_attributes(const char*, const Attributes_section_data*);
2787 // Helper to get an AEABI object attribute
2788 Object_attribute*
2789 get_aeabi_object_attribute(int tag) const
2791 Attributes_section_data* pasd = this->attributes_section_data_;
2792 gold_assert(pasd != NULL);
2793 Object_attribute* attr =
2794 pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2795 gold_assert(attr != NULL);
2796 return attr;
2800 // Methods to support stub-generations.
2803 // Group input sections for stub generation.
2804 void
2805 group_sections(Layout*, section_size_type, bool);
2807 // Scan a relocation for stub generation.
2808 void
2809 scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2810 const Sized_symbol<32>*, unsigned int,
2811 const Symbol_value<32>*,
2812 elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2814 // Scan a relocation section for stub.
2815 template<int sh_type>
2816 void
2817 scan_reloc_section_for_stubs(
2818 const Relocate_info<32, big_endian>* relinfo,
2819 const unsigned char* prelocs,
2820 size_t reloc_count,
2821 Output_section* output_section,
2822 bool needs_special_offset_handling,
2823 const unsigned char* view,
2824 elfcpp::Elf_types<32>::Elf_Addr view_address,
2825 section_size_type);
2827 // Fix .ARM.exidx section coverage.
2828 void
2829 fix_exidx_coverage(Layout*, const Input_objects*,
2830 Arm_output_section<big_endian>*, Symbol_table*);
2832 // Functors for STL set.
2833 struct output_section_address_less_than
2835 bool
2836 operator()(const Output_section* s1, const Output_section* s2) const
2837 { return s1->address() < s2->address(); }
2840 // Information about this specific target which we pass to the
2841 // general Target structure.
2842 static const Target::Target_info arm_info;
2844 // The types of GOT entries needed for this platform.
2845 // These values are exposed to the ABI in an incremental link.
2846 // Do not renumber existing values without changing the version
2847 // number of the .gnu_incremental_inputs section.
2848 enum Got_type
2850 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
2851 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
2852 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
2853 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
2854 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
2857 typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2859 // Map input section to Arm_input_section.
2860 typedef Unordered_map<Section_id,
2861 Arm_input_section<big_endian>*,
2862 Section_id_hash>
2863 Arm_input_section_map;
2865 // Map output addresses to relocs for Cortex-A8 erratum.
2866 typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2867 Cortex_a8_relocs_info;
2869 // The GOT section.
2870 Arm_output_data_got<big_endian>* got_;
2871 // The PLT section.
2872 Output_data_plt_arm<big_endian>* plt_;
2873 // The GOT PLT section.
2874 Output_data_space* got_plt_;
2875 // The dynamic reloc section.
2876 Reloc_section* rel_dyn_;
2877 // Relocs saved to avoid a COPY reloc.
2878 Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2879 // Space for variables copied with a COPY reloc.
2880 Output_data_space* dynbss_;
2881 // Offset of the GOT entry for the TLS module index.
2882 unsigned int got_mod_index_offset_;
2883 // True if the _TLS_MODULE_BASE_ symbol has been defined.
2884 bool tls_base_symbol_defined_;
2885 // Vector of Stub_tables created.
2886 Stub_table_list stub_tables_;
2887 // Stub factory.
2888 const Stub_factory &stub_factory_;
2889 // Whether we can use BLX.
2890 bool may_use_blx_;
2891 // Whether we force PIC branch veneers.
2892 bool should_force_pic_veneer_;
2893 // Map for locating Arm_input_sections.
2894 Arm_input_section_map arm_input_section_map_;
2895 // Attributes section data in output.
2896 Attributes_section_data* attributes_section_data_;
2897 // Whether we want to fix code for Cortex-A8 erratum.
2898 bool fix_cortex_a8_;
2899 // Map addresses to relocs for Cortex-A8 erratum.
2900 Cortex_a8_relocs_info cortex_a8_relocs_info_;
2903 template<bool big_endian>
2904 const Target::Target_info Target_arm<big_endian>::arm_info =
2906 32, // size
2907 big_endian, // is_big_endian
2908 elfcpp::EM_ARM, // machine_code
2909 false, // has_make_symbol
2910 false, // has_resolve
2911 false, // has_code_fill
2912 true, // is_default_stack_executable
2913 '\0', // wrap_char
2914 "/usr/lib/libc.so.1", // dynamic_linker
2915 0x8000, // default_text_segment_address
2916 0x1000, // abi_pagesize (overridable by -z max-page-size)
2917 0x1000, // common_pagesize (overridable by -z common-page-size)
2918 elfcpp::SHN_UNDEF, // small_common_shndx
2919 elfcpp::SHN_UNDEF, // large_common_shndx
2920 0, // small_common_section_flags
2921 0, // large_common_section_flags
2922 ".ARM.attributes", // attributes_section
2923 "aeabi" // attributes_vendor
2926 // Arm relocate functions class
2929 template<bool big_endian>
2930 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2932 public:
2933 typedef enum
2935 STATUS_OKAY, // No error during relocation.
2936 STATUS_OVERFLOW, // Relocation oveflow.
2937 STATUS_BAD_RELOC // Relocation cannot be applied.
2938 } Status;
2940 private:
2941 typedef Relocate_functions<32, big_endian> Base;
2942 typedef Arm_relocate_functions<big_endian> This;
2944 // Encoding of imm16 argument for movt and movw ARM instructions
2945 // from ARM ARM:
2947 // imm16 := imm4 | imm12
2949 // f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0
2950 // +-------+---------------+-------+-------+-----------------------+
2951 // | | |imm4 | |imm12 |
2952 // +-------+---------------+-------+-------+-----------------------+
2954 // Extract the relocation addend from VAL based on the ARM
2955 // instruction encoding described above.
2956 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2957 extract_arm_movw_movt_addend(
2958 typename elfcpp::Swap<32, big_endian>::Valtype val)
2960 // According to the Elf ABI for ARM Architecture the immediate
2961 // field is sign-extended to form the addend.
2962 return utils::sign_extend<16>(((val >> 4) & 0xf000) | (val & 0xfff));
2965 // Insert X into VAL based on the ARM instruction encoding described
2966 // above.
2967 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2968 insert_val_arm_movw_movt(
2969 typename elfcpp::Swap<32, big_endian>::Valtype val,
2970 typename elfcpp::Swap<32, big_endian>::Valtype x)
2972 val &= 0xfff0f000;
2973 val |= x & 0x0fff;
2974 val |= (x & 0xf000) << 4;
2975 return val;
2978 // Encoding of imm16 argument for movt and movw Thumb2 instructions
2979 // from ARM ARM:
2981 // imm16 := imm4 | i | imm3 | imm8
2983 // f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0
2984 // +---------+-+-----------+-------++-+-----+-------+---------------+
2985 // | |i| |imm4 || |imm3 | |imm8 |
2986 // +---------+-+-----------+-------++-+-----+-------+---------------+
2988 // Extract the relocation addend from VAL based on the Thumb2
2989 // instruction encoding described above.
2990 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2991 extract_thumb_movw_movt_addend(
2992 typename elfcpp::Swap<32, big_endian>::Valtype val)
2994 // According to the Elf ABI for ARM Architecture the immediate
2995 // field is sign-extended to form the addend.
2996 return utils::sign_extend<16>(((val >> 4) & 0xf000)
2997 | ((val >> 15) & 0x0800)
2998 | ((val >> 4) & 0x0700)
2999 | (val & 0x00ff));
3002 // Insert X into VAL based on the Thumb2 instruction encoding
3003 // described above.
3004 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3005 insert_val_thumb_movw_movt(
3006 typename elfcpp::Swap<32, big_endian>::Valtype val,
3007 typename elfcpp::Swap<32, big_endian>::Valtype x)
3009 val &= 0xfbf08f00;
3010 val |= (x & 0xf000) << 4;
3011 val |= (x & 0x0800) << 15;
3012 val |= (x & 0x0700) << 4;
3013 val |= (x & 0x00ff);
3014 return val;
3017 // Calculate the smallest constant Kn for the specified residual.
3018 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3019 static uint32_t
3020 calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3022 int32_t msb;
3024 if (residual == 0)
3025 return 0;
3026 // Determine the most significant bit in the residual and
3027 // align the resulting value to a 2-bit boundary.
3028 for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3030 // The desired shift is now (msb - 6), or zero, whichever
3031 // is the greater.
3032 return (((msb - 6) < 0) ? 0 : (msb - 6));
3035 // Calculate the final residual for the specified group index.
3036 // If the passed group index is less than zero, the method will return
3037 // the value of the specified residual without any change.
3038 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3039 static typename elfcpp::Swap<32, big_endian>::Valtype
3040 calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3041 const int group)
3043 for (int n = 0; n <= group; n++)
3045 // Calculate which part of the value to mask.
3046 uint32_t shift = calc_grp_kn(residual);
3047 // Calculate the residual for the next time around.
3048 residual &= ~(residual & (0xff << shift));
3051 return residual;
3054 // Calculate the value of Gn for the specified group index.
3055 // We return it in the form of an encoded constant-and-rotation.
3056 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3057 static typename elfcpp::Swap<32, big_endian>::Valtype
3058 calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3059 const int group)
3061 typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3062 uint32_t shift = 0;
3064 for (int n = 0; n <= group; n++)
3066 // Calculate which part of the value to mask.
3067 shift = calc_grp_kn(residual);
3068 // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3069 gn = residual & (0xff << shift);
3070 // Calculate the residual for the next time around.
3071 residual &= ~gn;
3073 // Return Gn in the form of an encoded constant-and-rotation.
3074 return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3077 public:
3078 // Handle ARM long branches.
3079 static typename This::Status
3080 arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3081 unsigned char*, const Sized_symbol<32>*,
3082 const Arm_relobj<big_endian>*, unsigned int,
3083 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3085 // Handle THUMB long branches.
3086 static typename This::Status
3087 thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3088 unsigned char*, const Sized_symbol<32>*,
3089 const Arm_relobj<big_endian>*, unsigned int,
3090 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3093 // Return the branch offset of a 32-bit THUMB branch.
3094 static inline int32_t
3095 thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3097 // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3098 // involving the J1 and J2 bits.
3099 uint32_t s = (upper_insn & (1U << 10)) >> 10;
3100 uint32_t upper = upper_insn & 0x3ffU;
3101 uint32_t lower = lower_insn & 0x7ffU;
3102 uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3103 uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3104 uint32_t i1 = j1 ^ s ? 0 : 1;
3105 uint32_t i2 = j2 ^ s ? 0 : 1;
3107 return utils::sign_extend<25>((s << 24) | (i1 << 23) | (i2 << 22)
3108 | (upper << 12) | (lower << 1));
3111 // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3112 // UPPER_INSN is the original upper instruction of the branch. Caller is
3113 // responsible for overflow checking and BLX offset adjustment.
3114 static inline uint16_t
3115 thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3117 uint32_t s = offset < 0 ? 1 : 0;
3118 uint32_t bits = static_cast<uint32_t>(offset);
3119 return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3122 // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3123 // LOWER_INSN is the original lower instruction of the branch. Caller is
3124 // responsible for overflow checking and BLX offset adjustment.
3125 static inline uint16_t
3126 thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3128 uint32_t s = offset < 0 ? 1 : 0;
3129 uint32_t bits = static_cast<uint32_t>(offset);
3130 return ((lower_insn & ~0x2fffU)
3131 | ((((bits >> 23) & 1) ^ !s) << 13)
3132 | ((((bits >> 22) & 1) ^ !s) << 11)
3133 | ((bits >> 1) & 0x7ffU));
3136 // Return the branch offset of a 32-bit THUMB conditional branch.
3137 static inline int32_t
3138 thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3140 uint32_t s = (upper_insn & 0x0400U) >> 10;
3141 uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3142 uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3143 uint32_t lower = (lower_insn & 0x07ffU);
3144 uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3146 return utils::sign_extend<21>((upper << 12) | (lower << 1));
3149 // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3150 // instruction. UPPER_INSN is the original upper instruction of the branch.
3151 // Caller is responsible for overflow checking.
3152 static inline uint16_t
3153 thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3155 uint32_t s = offset < 0 ? 1 : 0;
3156 uint32_t bits = static_cast<uint32_t>(offset);
3157 return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3160 // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3161 // instruction. LOWER_INSN is the original lower instruction of the branch.
3162 // Caller is reponsible for overflow checking.
3163 static inline uint16_t
3164 thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3166 uint32_t bits = static_cast<uint32_t>(offset);
3167 uint32_t j2 = (bits & 0x00080000U) >> 19;
3168 uint32_t j1 = (bits & 0x00040000U) >> 18;
3169 uint32_t lo = (bits & 0x00000ffeU) >> 1;
3171 return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3174 // R_ARM_ABS8: S + A
3175 static inline typename This::Status
3176 abs8(unsigned char* view,
3177 const Sized_relobj<32, big_endian>* object,
3178 const Symbol_value<32>* psymval)
3180 typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3181 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3182 Valtype* wv = reinterpret_cast<Valtype*>(view);
3183 Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3184 Reltype addend = utils::sign_extend<8>(val);
3185 Reltype x = psymval->value(object, addend);
3186 val = utils::bit_select(val, x, 0xffU);
3187 elfcpp::Swap<8, big_endian>::writeval(wv, val);
3189 // R_ARM_ABS8 permits signed or unsigned results.
3190 int signed_x = static_cast<int32_t>(x);
3191 return ((signed_x < -128 || signed_x > 255)
3192 ? This::STATUS_OVERFLOW
3193 : This::STATUS_OKAY);
3196 // R_ARM_THM_ABS5: S + A
3197 static inline typename This::Status
3198 thm_abs5(unsigned char* view,
3199 const Sized_relobj<32, big_endian>* object,
3200 const Symbol_value<32>* psymval)
3202 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3203 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3204 Valtype* wv = reinterpret_cast<Valtype*>(view);
3205 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3206 Reltype addend = (val & 0x7e0U) >> 6;
3207 Reltype x = psymval->value(object, addend);
3208 val = utils::bit_select(val, x << 6, 0x7e0U);
3209 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3211 // R_ARM_ABS16 permits signed or unsigned results.
3212 int signed_x = static_cast<int32_t>(x);
3213 return ((signed_x < -32768 || signed_x > 65535)
3214 ? This::STATUS_OVERFLOW
3215 : This::STATUS_OKAY);
3218 // R_ARM_ABS12: S + A
3219 static inline typename This::Status
3220 abs12(unsigned char* view,
3221 const Sized_relobj<32, big_endian>* object,
3222 const Symbol_value<32>* psymval)
3224 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3225 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3226 Valtype* wv = reinterpret_cast<Valtype*>(view);
3227 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3228 Reltype addend = val & 0x0fffU;
3229 Reltype x = psymval->value(object, addend);
3230 val = utils::bit_select(val, x, 0x0fffU);
3231 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3232 return (utils::has_overflow<12>(x)
3233 ? This::STATUS_OVERFLOW
3234 : This::STATUS_OKAY);
3237 // R_ARM_ABS16: S + A
3238 static inline typename This::Status
3239 abs16(unsigned char* view,
3240 const Sized_relobj<32, big_endian>* object,
3241 const Symbol_value<32>* psymval)
3243 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3244 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3245 Valtype* wv = reinterpret_cast<Valtype*>(view);
3246 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3247 Reltype addend = utils::sign_extend<16>(val);
3248 Reltype x = psymval->value(object, addend);
3249 val = utils::bit_select(val, x, 0xffffU);
3250 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3251 return (utils::has_signed_unsigned_overflow<16>(x)
3252 ? This::STATUS_OVERFLOW
3253 : This::STATUS_OKAY);
3256 // R_ARM_ABS32: (S + A) | T
3257 static inline typename This::Status
3258 abs32(unsigned char* view,
3259 const Sized_relobj<32, big_endian>* object,
3260 const Symbol_value<32>* psymval,
3261 Arm_address thumb_bit)
3263 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3264 Valtype* wv = reinterpret_cast<Valtype*>(view);
3265 Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
3266 Valtype x = psymval->value(object, addend) | thumb_bit;
3267 elfcpp::Swap<32, big_endian>::writeval(wv, x);
3268 return This::STATUS_OKAY;
3271 // R_ARM_REL32: (S + A) | T - P
3272 static inline typename This::Status
3273 rel32(unsigned char* view,
3274 const Sized_relobj<32, big_endian>* object,
3275 const Symbol_value<32>* psymval,
3276 Arm_address address,
3277 Arm_address thumb_bit)
3279 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3280 Valtype* wv = reinterpret_cast<Valtype*>(view);
3281 Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
3282 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3283 elfcpp::Swap<32, big_endian>::writeval(wv, x);
3284 return This::STATUS_OKAY;
3287 // R_ARM_THM_JUMP24: (S + A) | T - P
3288 static typename This::Status
3289 thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3290 const Symbol_value<32>* psymval, Arm_address address,
3291 Arm_address thumb_bit);
3293 // R_ARM_THM_JUMP6: S + A – P
3294 static inline typename This::Status
3295 thm_jump6(unsigned char* view,
3296 const Sized_relobj<32, big_endian>* object,
3297 const Symbol_value<32>* psymval,
3298 Arm_address address)
3300 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3301 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3302 Valtype* wv = reinterpret_cast<Valtype*>(view);
3303 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3304 // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3305 Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3306 Reltype x = (psymval->value(object, addend) - address);
3307 val = (val & 0xfd07) | ((x & 0x0040) << 3) | ((val & 0x003e) << 2);
3308 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3309 // CZB does only forward jumps.
3310 return ((x > 0x007e)
3311 ? This::STATUS_OVERFLOW
3312 : This::STATUS_OKAY);
3315 // R_ARM_THM_JUMP8: S + A – P
3316 static inline typename This::Status
3317 thm_jump8(unsigned char* view,
3318 const Sized_relobj<32, big_endian>* object,
3319 const Symbol_value<32>* psymval,
3320 Arm_address address)
3322 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3323 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3324 Valtype* wv = reinterpret_cast<Valtype*>(view);
3325 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3326 Reltype addend = utils::sign_extend<8>((val & 0x00ff) << 1);
3327 Reltype x = (psymval->value(object, addend) - address);
3328 elfcpp::Swap<16, big_endian>::writeval(wv, (val & 0xff00) | ((x & 0x01fe) >> 1));
3329 return (utils::has_overflow<8>(x)
3330 ? This::STATUS_OVERFLOW
3331 : This::STATUS_OKAY);
3334 // R_ARM_THM_JUMP11: S + A – P
3335 static inline typename This::Status
3336 thm_jump11(unsigned char* view,
3337 const Sized_relobj<32, big_endian>* object,
3338 const Symbol_value<32>* psymval,
3339 Arm_address address)
3341 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3342 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3343 Valtype* wv = reinterpret_cast<Valtype*>(view);
3344 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3345 Reltype addend = utils::sign_extend<11>((val & 0x07ff) << 1);
3346 Reltype x = (psymval->value(object, addend) - address);
3347 elfcpp::Swap<16, big_endian>::writeval(wv, (val & 0xf800) | ((x & 0x0ffe) >> 1));
3348 return (utils::has_overflow<11>(x)
3349 ? This::STATUS_OVERFLOW
3350 : This::STATUS_OKAY);
3353 // R_ARM_BASE_PREL: B(S) + A - P
3354 static inline typename This::Status
3355 base_prel(unsigned char* view,
3356 Arm_address origin,
3357 Arm_address address)
3359 Base::rel32(view, origin - address);
3360 return STATUS_OKAY;
3363 // R_ARM_BASE_ABS: B(S) + A
3364 static inline typename This::Status
3365 base_abs(unsigned char* view,
3366 Arm_address origin)
3368 Base::rel32(view, origin);
3369 return STATUS_OKAY;
3372 // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3373 static inline typename This::Status
3374 got_brel(unsigned char* view,
3375 typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3377 Base::rel32(view, got_offset);
3378 return This::STATUS_OKAY;
3381 // R_ARM_GOT_PREL: GOT(S) + A - P
3382 static inline typename This::Status
3383 got_prel(unsigned char* view,
3384 Arm_address got_entry,
3385 Arm_address address)
3387 Base::rel32(view, got_entry - address);
3388 return This::STATUS_OKAY;
3391 // R_ARM_PREL: (S + A) | T - P
3392 static inline typename This::Status
3393 prel31(unsigned char* view,
3394 const Sized_relobj<32, big_endian>* object,
3395 const Symbol_value<32>* psymval,
3396 Arm_address address,
3397 Arm_address thumb_bit)
3399 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3400 Valtype* wv = reinterpret_cast<Valtype*>(view);
3401 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3402 Valtype addend = utils::sign_extend<31>(val);
3403 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3404 val = utils::bit_select(val, x, 0x7fffffffU);
3405 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3406 return (utils::has_overflow<31>(x) ?
3407 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3410 // R_ARM_MOVW_ABS_NC: (S + A) | T (relative address base is )
3411 // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3412 // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3413 // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3414 static inline typename This::Status
3415 movw(unsigned char* view,
3416 const Sized_relobj<32, big_endian>* object,
3417 const Symbol_value<32>* psymval,
3418 Arm_address relative_address_base,
3419 Arm_address thumb_bit,
3420 bool check_overflow)
3422 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3423 Valtype* wv = reinterpret_cast<Valtype*>(view);
3424 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3425 Valtype addend = This::extract_arm_movw_movt_addend(val);
3426 Valtype x = ((psymval->value(object, addend) | thumb_bit)
3427 - relative_address_base);
3428 val = This::insert_val_arm_movw_movt(val, x);
3429 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3430 return ((check_overflow && utils::has_overflow<16>(x))
3431 ? This::STATUS_OVERFLOW
3432 : This::STATUS_OKAY);
3435 // R_ARM_MOVT_ABS: S + A (relative address base is 0)
3436 // R_ARM_MOVT_PREL: S + A - P
3437 // R_ARM_MOVT_BREL: S + A - B(S)
3438 static inline typename This::Status
3439 movt(unsigned char* view,
3440 const Sized_relobj<32, big_endian>* object,
3441 const Symbol_value<32>* psymval,
3442 Arm_address relative_address_base)
3444 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3445 Valtype* wv = reinterpret_cast<Valtype*>(view);
3446 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3447 Valtype addend = This::extract_arm_movw_movt_addend(val);
3448 Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3449 val = This::insert_val_arm_movw_movt(val, x);
3450 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3451 // FIXME: IHI0044D says that we should check for overflow.
3452 return This::STATUS_OKAY;
3455 // R_ARM_THM_MOVW_ABS_NC: S + A | T (relative_address_base is 0)
3456 // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3457 // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3458 // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3459 static inline typename This::Status
3460 thm_movw(unsigned char* view,
3461 const Sized_relobj<32, big_endian>* object,
3462 const Symbol_value<32>* psymval,
3463 Arm_address relative_address_base,
3464 Arm_address thumb_bit,
3465 bool check_overflow)
3467 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3468 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3469 Valtype* wv = reinterpret_cast<Valtype*>(view);
3470 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3471 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3472 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3473 Reltype x =
3474 (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3475 val = This::insert_val_thumb_movw_movt(val, x);
3476 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3477 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3478 return ((check_overflow && utils::has_overflow<16>(x))
3479 ? This::STATUS_OVERFLOW
3480 : This::STATUS_OKAY);
3483 // R_ARM_THM_MOVT_ABS: S + A (relative address base is 0)
3484 // R_ARM_THM_MOVT_PREL: S + A - P
3485 // R_ARM_THM_MOVT_BREL: S + A - B(S)
3486 static inline typename This::Status
3487 thm_movt(unsigned char* view,
3488 const Sized_relobj<32, big_endian>* object,
3489 const Symbol_value<32>* psymval,
3490 Arm_address relative_address_base)
3492 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3493 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3494 Valtype* wv = reinterpret_cast<Valtype*>(view);
3495 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3496 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3497 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3498 Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3499 val = This::insert_val_thumb_movw_movt(val, x);
3500 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3501 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3502 return This::STATUS_OKAY;
3505 // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3506 static inline typename This::Status
3507 thm_alu11(unsigned char* view,
3508 const Sized_relobj<32, big_endian>* object,
3509 const Symbol_value<32>* psymval,
3510 Arm_address address,
3511 Arm_address thumb_bit)
3513 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3514 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3515 Valtype* wv = reinterpret_cast<Valtype*>(view);
3516 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3517 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3519 // f e d c b|a|9|8 7 6 5|4|3 2 1 0||f|e d c|b a 9 8|7 6 5 4 3 2 1 0
3520 // -----------------------------------------------------------------------
3521 // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd |imm8
3522 // ADDW 1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd |imm8
3523 // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd |imm8
3524 // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd |imm8
3525 // SUBW 1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd |imm8
3526 // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd |imm8
3528 // Determine a sign for the addend.
3529 const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3530 || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3531 // Thumb2 addend encoding:
3532 // imm12 := i | imm3 | imm8
3533 int32_t addend = (insn & 0xff)
3534 | ((insn & 0x00007000) >> 4)
3535 | ((insn & 0x04000000) >> 15);
3536 // Apply a sign to the added.
3537 addend *= sign;
3539 int32_t x = (psymval->value(object, addend) | thumb_bit)
3540 - (address & 0xfffffffc);
3541 Reltype val = abs(x);
3542 // Mask out the value and a distinct part of the ADD/SUB opcode
3543 // (bits 7:5 of opword).
3544 insn = (insn & 0xfb0f8f00)
3545 | (val & 0xff)
3546 | ((val & 0x700) << 4)
3547 | ((val & 0x800) << 15);
3548 // Set the opcode according to whether the value to go in the
3549 // place is negative.
3550 if (x < 0)
3551 insn |= 0x00a00000;
3553 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3554 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3555 return ((val > 0xfff) ?
3556 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3559 // R_ARM_THM_PC8: S + A - Pa (Thumb)
3560 static inline typename This::Status
3561 thm_pc8(unsigned char* view,
3562 const Sized_relobj<32, big_endian>* object,
3563 const Symbol_value<32>* psymval,
3564 Arm_address address)
3566 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3567 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3568 Valtype* wv = reinterpret_cast<Valtype*>(view);
3569 Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3570 Reltype addend = ((insn & 0x00ff) << 2);
3571 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3572 Reltype val = abs(x);
3573 insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3575 elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3576 return ((val > 0x03fc)
3577 ? This::STATUS_OVERFLOW
3578 : This::STATUS_OKAY);
3581 // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3582 static inline typename This::Status
3583 thm_pc12(unsigned char* view,
3584 const Sized_relobj<32, big_endian>* object,
3585 const Symbol_value<32>* psymval,
3586 Arm_address address)
3588 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3589 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3590 Valtype* wv = reinterpret_cast<Valtype*>(view);
3591 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3592 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3593 // Determine a sign for the addend (positive if the U bit is 1).
3594 const int sign = (insn & 0x00800000) ? 1 : -1;
3595 int32_t addend = (insn & 0xfff);
3596 // Apply a sign to the added.
3597 addend *= sign;
3599 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3600 Reltype val = abs(x);
3601 // Mask out and apply the value and the U bit.
3602 insn = (insn & 0xff7ff000) | (val & 0xfff);
3603 // Set the U bit according to whether the value to go in the
3604 // place is positive.
3605 if (x >= 0)
3606 insn |= 0x00800000;
3608 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3609 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3610 return ((val > 0xfff) ?
3611 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3614 // R_ARM_V4BX
3615 static inline typename This::Status
3616 v4bx(const Relocate_info<32, big_endian>* relinfo,
3617 unsigned char* view,
3618 const Arm_relobj<big_endian>* object,
3619 const Arm_address address,
3620 const bool is_interworking)
3623 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3624 Valtype* wv = reinterpret_cast<Valtype*>(view);
3625 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3627 // Ensure that we have a BX instruction.
3628 gold_assert((val & 0x0ffffff0) == 0x012fff10);
3629 const uint32_t reg = (val & 0xf);
3630 if (is_interworking && reg != 0xf)
3632 Stub_table<big_endian>* stub_table =
3633 object->stub_table(relinfo->data_shndx);
3634 gold_assert(stub_table != NULL);
3636 Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3637 gold_assert(stub != NULL);
3639 int32_t veneer_address =
3640 stub_table->address() + stub->offset() - 8 - address;
3641 gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3642 && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3643 // Replace with a branch to veneer (B <addr>)
3644 val = (val & 0xf0000000) | 0x0a000000
3645 | ((veneer_address >> 2) & 0x00ffffff);
3647 else
3649 // Preserve Rm (lowest four bits) and the condition code
3650 // (highest four bits). Other bits encode MOV PC,Rm.
3651 val = (val & 0xf000000f) | 0x01a0f000;
3653 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3654 return This::STATUS_OKAY;
3657 // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3658 // R_ARM_ALU_PC_G0: ((S + A) | T) - P
3659 // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3660 // R_ARM_ALU_PC_G1: ((S + A) | T) - P
3661 // R_ARM_ALU_PC_G2: ((S + A) | T) - P
3662 // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3663 // R_ARM_ALU_SB_G0: ((S + A) | T) - B(S)
3664 // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3665 // R_ARM_ALU_SB_G1: ((S + A) | T) - B(S)
3666 // R_ARM_ALU_SB_G2: ((S + A) | T) - B(S)
3667 static inline typename This::Status
3668 arm_grp_alu(unsigned char* view,
3669 const Sized_relobj<32, big_endian>* object,
3670 const Symbol_value<32>* psymval,
3671 const int group,
3672 Arm_address address,
3673 Arm_address thumb_bit,
3674 bool check_overflow)
3676 gold_assert(group >= 0 && group < 3);
3677 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3678 Valtype* wv = reinterpret_cast<Valtype*>(view);
3679 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3681 // ALU group relocations are allowed only for the ADD/SUB instructions.
3682 // (0x00800000 - ADD, 0x00400000 - SUB)
3683 const Valtype opcode = insn & 0x01e00000;
3684 if (opcode != 0x00800000 && opcode != 0x00400000)
3685 return This::STATUS_BAD_RELOC;
3687 // Determine a sign for the addend.
3688 const int sign = (opcode == 0x00800000) ? 1 : -1;
3689 // shifter = rotate_imm * 2
3690 const uint32_t shifter = (insn & 0xf00) >> 7;
3691 // Initial addend value.
3692 int32_t addend = insn & 0xff;
3693 // Rotate addend right by shifter.
3694 addend = (addend >> shifter) | (addend << (32 - shifter));
3695 // Apply a sign to the added.
3696 addend *= sign;
3698 int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3699 Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3700 // Check for overflow if required
3701 if (check_overflow
3702 && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3703 return This::STATUS_OVERFLOW;
3705 // Mask out the value and the ADD/SUB part of the opcode; take care
3706 // not to destroy the S bit.
3707 insn &= 0xff1ff000;
3708 // Set the opcode according to whether the value to go in the
3709 // place is negative.
3710 insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3711 // Encode the offset (encoded Gn).
3712 insn |= gn;
3714 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3715 return This::STATUS_OKAY;
3718 // R_ARM_LDR_PC_G0: S + A - P
3719 // R_ARM_LDR_PC_G1: S + A - P
3720 // R_ARM_LDR_PC_G2: S + A - P
3721 // R_ARM_LDR_SB_G0: S + A - B(S)
3722 // R_ARM_LDR_SB_G1: S + A - B(S)
3723 // R_ARM_LDR_SB_G2: S + A - B(S)
3724 static inline typename This::Status
3725 arm_grp_ldr(unsigned char* view,
3726 const Sized_relobj<32, big_endian>* object,
3727 const Symbol_value<32>* psymval,
3728 const int group,
3729 Arm_address address)
3731 gold_assert(group >= 0 && group < 3);
3732 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3733 Valtype* wv = reinterpret_cast<Valtype*>(view);
3734 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3736 const int sign = (insn & 0x00800000) ? 1 : -1;
3737 int32_t addend = (insn & 0xfff) * sign;
3738 int32_t x = (psymval->value(object, addend) - address);
3739 // Calculate the relevant G(n-1) value to obtain this stage residual.
3740 Valtype residual =
3741 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3742 if (residual >= 0x1000)
3743 return This::STATUS_OVERFLOW;
3745 // Mask out the value and U bit.
3746 insn &= 0xff7ff000;
3747 // Set the U bit for non-negative values.
3748 if (x >= 0)
3749 insn |= 0x00800000;
3750 insn |= residual;
3752 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3753 return This::STATUS_OKAY;
3756 // R_ARM_LDRS_PC_G0: S + A - P
3757 // R_ARM_LDRS_PC_G1: S + A - P
3758 // R_ARM_LDRS_PC_G2: S + A - P
3759 // R_ARM_LDRS_SB_G0: S + A - B(S)
3760 // R_ARM_LDRS_SB_G1: S + A - B(S)
3761 // R_ARM_LDRS_SB_G2: S + A - B(S)
3762 static inline typename This::Status
3763 arm_grp_ldrs(unsigned char* view,
3764 const Sized_relobj<32, big_endian>* object,
3765 const Symbol_value<32>* psymval,
3766 const int group,
3767 Arm_address address)
3769 gold_assert(group >= 0 && group < 3);
3770 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3771 Valtype* wv = reinterpret_cast<Valtype*>(view);
3772 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3774 const int sign = (insn & 0x00800000) ? 1 : -1;
3775 int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3776 int32_t x = (psymval->value(object, addend) - address);
3777 // Calculate the relevant G(n-1) value to obtain this stage residual.
3778 Valtype residual =
3779 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3780 if (residual >= 0x100)
3781 return This::STATUS_OVERFLOW;
3783 // Mask out the value and U bit.
3784 insn &= 0xff7ff0f0;
3785 // Set the U bit for non-negative values.
3786 if (x >= 0)
3787 insn |= 0x00800000;
3788 insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3790 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3791 return This::STATUS_OKAY;
3794 // R_ARM_LDC_PC_G0: S + A - P
3795 // R_ARM_LDC_PC_G1: S + A - P
3796 // R_ARM_LDC_PC_G2: S + A - P
3797 // R_ARM_LDC_SB_G0: S + A - B(S)
3798 // R_ARM_LDC_SB_G1: S + A - B(S)
3799 // R_ARM_LDC_SB_G2: S + A - B(S)
3800 static inline typename This::Status
3801 arm_grp_ldc(unsigned char* view,
3802 const Sized_relobj<32, big_endian>* object,
3803 const Symbol_value<32>* psymval,
3804 const int group,
3805 Arm_address address)
3807 gold_assert(group >= 0 && group < 3);
3808 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3809 Valtype* wv = reinterpret_cast<Valtype*>(view);
3810 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3812 const int sign = (insn & 0x00800000) ? 1 : -1;
3813 int32_t addend = ((insn & 0xff) << 2) * sign;
3814 int32_t x = (psymval->value(object, addend) - address);
3815 // Calculate the relevant G(n-1) value to obtain this stage residual.
3816 Valtype residual =
3817 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3818 if ((residual & 0x3) != 0 || residual >= 0x400)
3819 return This::STATUS_OVERFLOW;
3821 // Mask out the value and U bit.
3822 insn &= 0xff7fff00;
3823 // Set the U bit for non-negative values.
3824 if (x >= 0)
3825 insn |= 0x00800000;
3826 insn |= (residual >> 2);
3828 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3829 return This::STATUS_OKAY;
3833 // Relocate ARM long branches. This handles relocation types
3834 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3835 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3836 // undefined and we do not use PLT in this relocation. In such a case,
3837 // the branch is converted into an NOP.
3839 template<bool big_endian>
3840 typename Arm_relocate_functions<big_endian>::Status
3841 Arm_relocate_functions<big_endian>::arm_branch_common(
3842 unsigned int r_type,
3843 const Relocate_info<32, big_endian>* relinfo,
3844 unsigned char* view,
3845 const Sized_symbol<32>* gsym,
3846 const Arm_relobj<big_endian>* object,
3847 unsigned int r_sym,
3848 const Symbol_value<32>* psymval,
3849 Arm_address address,
3850 Arm_address thumb_bit,
3851 bool is_weakly_undefined_without_plt)
3853 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3854 Valtype* wv = reinterpret_cast<Valtype*>(view);
3855 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3857 bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3858 && ((val & 0x0f000000UL) == 0x0a000000UL);
3859 bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3860 bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3861 && ((val & 0x0f000000UL) == 0x0b000000UL);
3862 bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3863 bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3865 // Check that the instruction is valid.
3866 if (r_type == elfcpp::R_ARM_CALL)
3868 if (!insn_is_uncond_bl && !insn_is_blx)
3869 return This::STATUS_BAD_RELOC;
3871 else if (r_type == elfcpp::R_ARM_JUMP24)
3873 if (!insn_is_b && !insn_is_cond_bl)
3874 return This::STATUS_BAD_RELOC;
3876 else if (r_type == elfcpp::R_ARM_PLT32)
3878 if (!insn_is_any_branch)
3879 return This::STATUS_BAD_RELOC;
3881 else if (r_type == elfcpp::R_ARM_XPC25)
3883 // FIXME: AAELF document IH0044C does not say much about it other
3884 // than it being obsolete.
3885 if (!insn_is_any_branch)
3886 return This::STATUS_BAD_RELOC;
3888 else
3889 gold_unreachable();
3891 // A branch to an undefined weak symbol is turned into a jump to
3892 // the next instruction unless a PLT entry will be created.
3893 // Do the same for local undefined symbols.
3894 // The jump to the next instruction is optimized as a NOP depending
3895 // on the architecture.
3896 const Target_arm<big_endian>* arm_target =
3897 Target_arm<big_endian>::default_target();
3898 if (is_weakly_undefined_without_plt)
3900 gold_assert(!parameters->options().relocatable());
3901 Valtype cond = val & 0xf0000000U;
3902 if (arm_target->may_use_arm_nop())
3903 val = cond | 0x0320f000;
3904 else
3905 val = cond | 0x01a00000; // Using pre-UAL nop: mov r0, r0.
3906 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3907 return This::STATUS_OKAY;
3910 Valtype addend = utils::sign_extend<26>(val << 2);
3911 Valtype branch_target = psymval->value(object, addend);
3912 int32_t branch_offset = branch_target - address;
3914 // We need a stub if the branch offset is too large or if we need
3915 // to switch mode.
3916 bool may_use_blx = arm_target->may_use_blx();
3917 Reloc_stub* stub = NULL;
3919 if (!parameters->options().relocatable()
3920 && (utils::has_overflow<26>(branch_offset)
3921 || ((thumb_bit != 0)
3922 && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3924 Valtype unadjusted_branch_target = psymval->value(object, 0);
3926 Stub_type stub_type =
3927 Reloc_stub::stub_type_for_reloc(r_type, address,
3928 unadjusted_branch_target,
3929 (thumb_bit != 0));
3930 if (stub_type != arm_stub_none)
3932 Stub_table<big_endian>* stub_table =
3933 object->stub_table(relinfo->data_shndx);
3934 gold_assert(stub_table != NULL);
3936 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3937 stub = stub_table->find_reloc_stub(stub_key);
3938 gold_assert(stub != NULL);
3939 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3940 branch_target = stub_table->address() + stub->offset() + addend;
3941 branch_offset = branch_target - address;
3942 gold_assert(!utils::has_overflow<26>(branch_offset));
3946 // At this point, if we still need to switch mode, the instruction
3947 // must either be a BLX or a BL that can be converted to a BLX.
3948 if (thumb_bit != 0)
3950 // Turn BL to BLX.
3951 gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3952 val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3955 val = utils::bit_select(val, (branch_offset >> 2), 0xffffffUL);
3956 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3957 return (utils::has_overflow<26>(branch_offset)
3958 ? This::STATUS_OVERFLOW : This::STATUS_OKAY);
3961 // Relocate THUMB long branches. This handles relocation types
3962 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3963 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3964 // undefined and we do not use PLT in this relocation. In such a case,
3965 // the branch is converted into an NOP.
3967 template<bool big_endian>
3968 typename Arm_relocate_functions<big_endian>::Status
3969 Arm_relocate_functions<big_endian>::thumb_branch_common(
3970 unsigned int r_type,
3971 const Relocate_info<32, big_endian>* relinfo,
3972 unsigned char* view,
3973 const Sized_symbol<32>* gsym,
3974 const Arm_relobj<big_endian>* object,
3975 unsigned int r_sym,
3976 const Symbol_value<32>* psymval,
3977 Arm_address address,
3978 Arm_address thumb_bit,
3979 bool is_weakly_undefined_without_plt)
3981 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3982 Valtype* wv = reinterpret_cast<Valtype*>(view);
3983 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
3984 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
3986 // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
3987 // into account.
3988 bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
3989 bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
3991 // Check that the instruction is valid.
3992 if (r_type == elfcpp::R_ARM_THM_CALL)
3994 if (!is_bl_insn && !is_blx_insn)
3995 return This::STATUS_BAD_RELOC;
3997 else if (r_type == elfcpp::R_ARM_THM_JUMP24)
3999 // This cannot be a BLX.
4000 if (!is_bl_insn)
4001 return This::STATUS_BAD_RELOC;
4003 else if (r_type == elfcpp::R_ARM_THM_XPC22)
4005 // Check for Thumb to Thumb call.
4006 if (!is_blx_insn)
4007 return This::STATUS_BAD_RELOC;
4008 if (thumb_bit != 0)
4010 gold_warning(_("%s: Thumb BLX instruction targets "
4011 "thumb function '%s'."),
4012 object->name().c_str(),
4013 (gsym ? gsym->name() : "(local)"));
4014 // Convert BLX to BL.
4015 lower_insn |= 0x1000U;
4018 else
4019 gold_unreachable();
4021 // A branch to an undefined weak symbol is turned into a jump to
4022 // the next instruction unless a PLT entry will be created.
4023 // The jump to the next instruction is optimized as a NOP.W for
4024 // Thumb-2 enabled architectures.
4025 const Target_arm<big_endian>* arm_target =
4026 Target_arm<big_endian>::default_target();
4027 if (is_weakly_undefined_without_plt)
4029 gold_assert(!parameters->options().relocatable());
4030 if (arm_target->may_use_thumb2_nop())
4032 elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4033 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4035 else
4037 elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4038 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4040 return This::STATUS_OKAY;
4043 int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4044 Arm_address branch_target = psymval->value(object, addend);
4046 // For BLX, bit 1 of target address comes from bit 1 of base address.
4047 bool may_use_blx = arm_target->may_use_blx();
4048 if (thumb_bit == 0 && may_use_blx)
4049 branch_target = utils::bit_select(branch_target, address, 0x2);
4051 int32_t branch_offset = branch_target - address;
4053 // We need a stub if the branch offset is too large or if we need
4054 // to switch mode.
4055 bool thumb2 = arm_target->using_thumb2();
4056 if (!parameters->options().relocatable()
4057 && ((!thumb2 && utils::has_overflow<23>(branch_offset))
4058 || (thumb2 && utils::has_overflow<25>(branch_offset))
4059 || ((thumb_bit == 0)
4060 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4061 || r_type == elfcpp::R_ARM_THM_JUMP24))))
4063 Arm_address unadjusted_branch_target = psymval->value(object, 0);
4065 Stub_type stub_type =
4066 Reloc_stub::stub_type_for_reloc(r_type, address,
4067 unadjusted_branch_target,
4068 (thumb_bit != 0));
4070 if (stub_type != arm_stub_none)
4072 Stub_table<big_endian>* stub_table =
4073 object->stub_table(relinfo->data_shndx);
4074 gold_assert(stub_table != NULL);
4076 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4077 Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4078 gold_assert(stub != NULL);
4079 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4080 branch_target = stub_table->address() + stub->offset() + addend;
4081 if (thumb_bit == 0 && may_use_blx)
4082 branch_target = utils::bit_select(branch_target, address, 0x2);
4083 branch_offset = branch_target - address;
4087 // At this point, if we still need to switch mode, the instruction
4088 // must either be a BLX or a BL that can be converted to a BLX.
4089 if (thumb_bit == 0)
4091 gold_assert(may_use_blx
4092 && (r_type == elfcpp::R_ARM_THM_CALL
4093 || r_type == elfcpp::R_ARM_THM_XPC22));
4094 // Make sure this is a BLX.
4095 lower_insn &= ~0x1000U;
4097 else
4099 // Make sure this is a BL.
4100 lower_insn |= 0x1000U;
4103 // For a BLX instruction, make sure that the relocation is rounded up
4104 // to a word boundary. This follows the semantics of the instruction
4105 // which specifies that bit 1 of the target address will come from bit
4106 // 1 of the base address.
4107 if ((lower_insn & 0x5000U) == 0x4000U)
4108 gold_assert((branch_offset & 3) == 0);
4110 // Put BRANCH_OFFSET back into the insn. Assumes two's complement.
4111 // We use the Thumb-2 encoding, which is safe even if dealing with
4112 // a Thumb-1 instruction by virtue of our overflow check above. */
4113 upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4114 lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4116 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4117 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4119 gold_assert(!utils::has_overflow<25>(branch_offset));
4121 return ((thumb2
4122 ? utils::has_overflow<25>(branch_offset)
4123 : utils::has_overflow<23>(branch_offset))
4124 ? This::STATUS_OVERFLOW
4125 : This::STATUS_OKAY);
4128 // Relocate THUMB-2 long conditional branches.
4129 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
4130 // undefined and we do not use PLT in this relocation. In such a case,
4131 // the branch is converted into an NOP.
4133 template<bool big_endian>
4134 typename Arm_relocate_functions<big_endian>::Status
4135 Arm_relocate_functions<big_endian>::thm_jump19(
4136 unsigned char* view,
4137 const Arm_relobj<big_endian>* object,
4138 const Symbol_value<32>* psymval,
4139 Arm_address address,
4140 Arm_address thumb_bit)
4142 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4143 Valtype* wv = reinterpret_cast<Valtype*>(view);
4144 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4145 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4146 int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4148 Arm_address branch_target = psymval->value(object, addend);
4149 int32_t branch_offset = branch_target - address;
4151 // ??? Should handle interworking? GCC might someday try to
4152 // use this for tail calls.
4153 // FIXME: We do support thumb entry to PLT yet.
4154 if (thumb_bit == 0)
4156 gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4157 return This::STATUS_BAD_RELOC;
4160 // Put RELOCATION back into the insn.
4161 upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4162 lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4164 // Put the relocated value back in the object file:
4165 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4166 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4168 return (utils::has_overflow<21>(branch_offset)
4169 ? This::STATUS_OVERFLOW
4170 : This::STATUS_OKAY);
4173 // Get the GOT section, creating it if necessary.
4175 template<bool big_endian>
4176 Arm_output_data_got<big_endian>*
4177 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4179 if (this->got_ == NULL)
4181 gold_assert(symtab != NULL && layout != NULL);
4183 this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4185 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4186 (elfcpp::SHF_ALLOC
4187 | elfcpp::SHF_WRITE),
4188 this->got_, ORDER_RELRO, true);
4190 // The old GNU linker creates a .got.plt section. We just
4191 // create another set of data in the .got section. Note that we
4192 // always create a PLT if we create a GOT, although the PLT
4193 // might be empty.
4194 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4195 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4196 (elfcpp::SHF_ALLOC
4197 | elfcpp::SHF_WRITE),
4198 this->got_plt_, ORDER_DATA, false);
4200 // The first three entries are reserved.
4201 this->got_plt_->set_current_data_size(3 * 4);
4203 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4204 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4205 Symbol_table::PREDEFINED,
4206 this->got_plt_,
4207 0, 0, elfcpp::STT_OBJECT,
4208 elfcpp::STB_LOCAL,
4209 elfcpp::STV_HIDDEN, 0,
4210 false, false);
4212 return this->got_;
4215 // Get the dynamic reloc section, creating it if necessary.
4217 template<bool big_endian>
4218 typename Target_arm<big_endian>::Reloc_section*
4219 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4221 if (this->rel_dyn_ == NULL)
4223 gold_assert(layout != NULL);
4224 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4225 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4226 elfcpp::SHF_ALLOC, this->rel_dyn_,
4227 ORDER_DYNAMIC_RELOCS, false);
4229 return this->rel_dyn_;
4232 // Insn_template methods.
4234 // Return byte size of an instruction template.
4236 size_t
4237 Insn_template::size() const
4239 switch (this->type())
4241 case THUMB16_TYPE:
4242 case THUMB16_SPECIAL_TYPE:
4243 return 2;
4244 case ARM_TYPE:
4245 case THUMB32_TYPE:
4246 case DATA_TYPE:
4247 return 4;
4248 default:
4249 gold_unreachable();
4253 // Return alignment of an instruction template.
4255 unsigned
4256 Insn_template::alignment() const
4258 switch (this->type())
4260 case THUMB16_TYPE:
4261 case THUMB16_SPECIAL_TYPE:
4262 case THUMB32_TYPE:
4263 return 2;
4264 case ARM_TYPE:
4265 case DATA_TYPE:
4266 return 4;
4267 default:
4268 gold_unreachable();
4272 // Stub_template methods.
4274 Stub_template::Stub_template(
4275 Stub_type type, const Insn_template* insns,
4276 size_t insn_count)
4277 : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4278 entry_in_thumb_mode_(false), relocs_()
4280 off_t offset = 0;
4282 // Compute byte size and alignment of stub template.
4283 for (size_t i = 0; i < insn_count; i++)
4285 unsigned insn_alignment = insns[i].alignment();
4286 size_t insn_size = insns[i].size();
4287 gold_assert((offset & (insn_alignment - 1)) == 0);
4288 this->alignment_ = std::max(this->alignment_, insn_alignment);
4289 switch (insns[i].type())
4291 case Insn_template::THUMB16_TYPE:
4292 case Insn_template::THUMB16_SPECIAL_TYPE:
4293 if (i == 0)
4294 this->entry_in_thumb_mode_ = true;
4295 break;
4297 case Insn_template::THUMB32_TYPE:
4298 if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4299 this->relocs_.push_back(Reloc(i, offset));
4300 if (i == 0)
4301 this->entry_in_thumb_mode_ = true;
4302 break;
4304 case Insn_template::ARM_TYPE:
4305 // Handle cases where the target is encoded within the
4306 // instruction.
4307 if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4308 this->relocs_.push_back(Reloc(i, offset));
4309 break;
4311 case Insn_template::DATA_TYPE:
4312 // Entry point cannot be data.
4313 gold_assert(i != 0);
4314 this->relocs_.push_back(Reloc(i, offset));
4315 break;
4317 default:
4318 gold_unreachable();
4320 offset += insn_size;
4322 this->size_ = offset;
4325 // Stub methods.
4327 // Template to implement do_write for a specific target endianness.
4329 template<bool big_endian>
4330 void inline
4331 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4333 const Stub_template* stub_template = this->stub_template();
4334 const Insn_template* insns = stub_template->insns();
4336 // FIXME: We do not handle BE8 encoding yet.
4337 unsigned char* pov = view;
4338 for (size_t i = 0; i < stub_template->insn_count(); i++)
4340 switch (insns[i].type())
4342 case Insn_template::THUMB16_TYPE:
4343 elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4344 break;
4345 case Insn_template::THUMB16_SPECIAL_TYPE:
4346 elfcpp::Swap<16, big_endian>::writeval(
4347 pov,
4348 this->thumb16_special(i));
4349 break;
4350 case Insn_template::THUMB32_TYPE:
4352 uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4353 uint32_t lo = insns[i].data() & 0xffff;
4354 elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4355 elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4357 break;
4358 case Insn_template::ARM_TYPE:
4359 case Insn_template::DATA_TYPE:
4360 elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4361 break;
4362 default:
4363 gold_unreachable();
4365 pov += insns[i].size();
4367 gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4370 // Reloc_stub::Key methods.
4372 // Dump a Key as a string for debugging.
4374 std::string
4375 Reloc_stub::Key::name() const
4377 if (this->r_sym_ == invalid_index)
4379 // Global symbol key name
4380 // <stub-type>:<symbol name>:<addend>.
4381 const std::string sym_name = this->u_.symbol->name();
4382 // We need to print two hex number and two colons. So just add 100 bytes
4383 // to the symbol name size.
4384 size_t len = sym_name.size() + 100;
4385 char* buffer = new char[len];
4386 int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4387 sym_name.c_str(), this->addend_);
4388 gold_assert(c > 0 && c < static_cast<int>(len));
4389 delete[] buffer;
4390 return std::string(buffer);
4392 else
4394 // local symbol key name
4395 // <stub-type>:<object>:<r_sym>:<addend>.
4396 const size_t len = 200;
4397 char buffer[len];
4398 int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4399 this->u_.relobj, this->r_sym_, this->addend_);
4400 gold_assert(c > 0 && c < static_cast<int>(len));
4401 return std::string(buffer);
4405 // Reloc_stub methods.
4407 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4408 // LOCATION to DESTINATION.
4409 // This code is based on the arm_type_of_stub function in
4410 // bfd/elf32-arm.c. We have changed the interface a liitle to keep the Stub
4411 // class simple.
4413 Stub_type
4414 Reloc_stub::stub_type_for_reloc(
4415 unsigned int r_type,
4416 Arm_address location,
4417 Arm_address destination,
4418 bool target_is_thumb)
4420 Stub_type stub_type = arm_stub_none;
4422 // This is a bit ugly but we want to avoid using a templated class for
4423 // big and little endianities.
4424 bool may_use_blx;
4425 bool should_force_pic_veneer;
4426 bool thumb2;
4427 bool thumb_only;
4428 if (parameters->target().is_big_endian())
4430 const Target_arm<true>* big_endian_target =
4431 Target_arm<true>::default_target();
4432 may_use_blx = big_endian_target->may_use_blx();
4433 should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4434 thumb2 = big_endian_target->using_thumb2();
4435 thumb_only = big_endian_target->using_thumb_only();
4437 else
4439 const Target_arm<false>* little_endian_target =
4440 Target_arm<false>::default_target();
4441 may_use_blx = little_endian_target->may_use_blx();
4442 should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4443 thumb2 = little_endian_target->using_thumb2();
4444 thumb_only = little_endian_target->using_thumb_only();
4447 int64_t branch_offset;
4448 if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4450 // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4451 // base address (instruction address + 4).
4452 if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4453 destination = utils::bit_select(destination, location, 0x2);
4454 branch_offset = static_cast<int64_t>(destination) - location;
4456 // Handle cases where:
4457 // - this call goes too far (different Thumb/Thumb2 max
4458 // distance)
4459 // - it's a Thumb->Arm call and blx is not available, or it's a
4460 // Thumb->Arm branch (not bl). A stub is needed in this case.
4461 if ((!thumb2
4462 && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4463 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4464 || (thumb2
4465 && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4466 || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4467 || ((!target_is_thumb)
4468 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4469 || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4471 if (target_is_thumb)
4473 // Thumb to thumb.
4474 if (!thumb_only)
4476 stub_type = (parameters->options().shared()
4477 || should_force_pic_veneer)
4478 // PIC stubs.
4479 ? ((may_use_blx
4480 && (r_type == elfcpp::R_ARM_THM_CALL))
4481 // V5T and above. Stub starts with ARM code, so
4482 // we must be able to switch mode before
4483 // reaching it, which is only possible for 'bl'
4484 // (ie R_ARM_THM_CALL relocation).
4485 ? arm_stub_long_branch_any_thumb_pic
4486 // On V4T, use Thumb code only.
4487 : arm_stub_long_branch_v4t_thumb_thumb_pic)
4489 // non-PIC stubs.
4490 : ((may_use_blx
4491 && (r_type == elfcpp::R_ARM_THM_CALL))
4492 ? arm_stub_long_branch_any_any // V5T and above.
4493 : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4495 else
4497 stub_type = (parameters->options().shared()
4498 || should_force_pic_veneer)
4499 ? arm_stub_long_branch_thumb_only_pic // PIC stub.
4500 : arm_stub_long_branch_thumb_only; // non-PIC stub.
4503 else
4505 // Thumb to arm.
4507 // FIXME: We should check that the input section is from an
4508 // object that has interwork enabled.
4510 stub_type = (parameters->options().shared()
4511 || should_force_pic_veneer)
4512 // PIC stubs.
4513 ? ((may_use_blx
4514 && (r_type == elfcpp::R_ARM_THM_CALL))
4515 ? arm_stub_long_branch_any_arm_pic // V5T and above.
4516 : arm_stub_long_branch_v4t_thumb_arm_pic) // V4T.
4518 // non-PIC stubs.
4519 : ((may_use_blx
4520 && (r_type == elfcpp::R_ARM_THM_CALL))
4521 ? arm_stub_long_branch_any_any // V5T and above.
4522 : arm_stub_long_branch_v4t_thumb_arm); // V4T.
4524 // Handle v4t short branches.
4525 if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4526 && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4527 && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4528 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4532 else if (r_type == elfcpp::R_ARM_CALL
4533 || r_type == elfcpp::R_ARM_JUMP24
4534 || r_type == elfcpp::R_ARM_PLT32)
4536 branch_offset = static_cast<int64_t>(destination) - location;
4537 if (target_is_thumb)
4539 // Arm to thumb.
4541 // FIXME: We should check that the input section is from an
4542 // object that has interwork enabled.
4544 // We have an extra 2-bytes reach because of
4545 // the mode change (bit 24 (H) of BLX encoding).
4546 if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4547 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4548 || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4549 || (r_type == elfcpp::R_ARM_JUMP24)
4550 || (r_type == elfcpp::R_ARM_PLT32))
4552 stub_type = (parameters->options().shared()
4553 || should_force_pic_veneer)
4554 // PIC stubs.
4555 ? (may_use_blx
4556 ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4557 : arm_stub_long_branch_v4t_arm_thumb_pic) // V4T stub.
4559 // non-PIC stubs.
4560 : (may_use_blx
4561 ? arm_stub_long_branch_any_any // V5T and above.
4562 : arm_stub_long_branch_v4t_arm_thumb); // V4T.
4565 else
4567 // Arm to arm.
4568 if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4569 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4571 stub_type = (parameters->options().shared()
4572 || should_force_pic_veneer)
4573 ? arm_stub_long_branch_any_arm_pic // PIC stubs.
4574 : arm_stub_long_branch_any_any; /// non-PIC.
4579 return stub_type;
4582 // Cortex_a8_stub methods.
4584 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4585 // I is the position of the instruction template in the stub template.
4587 uint16_t
4588 Cortex_a8_stub::do_thumb16_special(size_t i)
4590 // The only use of this is to copy condition code from a conditional
4591 // branch being worked around to the corresponding conditional branch in
4592 // to the stub.
4593 gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4594 && i == 0);
4595 uint16_t data = this->stub_template()->insns()[i].data();
4596 gold_assert((data & 0xff00U) == 0xd000U);
4597 data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4598 return data;
4601 // Stub_factory methods.
4603 Stub_factory::Stub_factory()
4605 // The instruction template sequences are declared as static
4606 // objects and initialized first time the constructor runs.
4608 // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4609 // to reach the stub if necessary.
4610 static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4612 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4613 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4614 // dcd R_ARM_ABS32(X)
4617 // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4618 // available.
4619 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4621 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4622 Insn_template::arm_insn(0xe12fff1c), // bx ip
4623 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4624 // dcd R_ARM_ABS32(X)
4627 // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4628 static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4630 Insn_template::thumb16_insn(0xb401), // push {r0}
4631 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4632 Insn_template::thumb16_insn(0x4684), // mov ip, r0
4633 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4634 Insn_template::thumb16_insn(0x4760), // bx ip
4635 Insn_template::thumb16_insn(0xbf00), // nop
4636 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4637 // dcd R_ARM_ABS32(X)
4640 // V4T Thumb -> Thumb long branch stub. Using the stack is not
4641 // allowed.
4642 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4644 Insn_template::thumb16_insn(0x4778), // bx pc
4645 Insn_template::thumb16_insn(0x46c0), // nop
4646 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4647 Insn_template::arm_insn(0xe12fff1c), // bx ip
4648 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4649 // dcd R_ARM_ABS32(X)
4652 // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4653 // available.
4654 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4656 Insn_template::thumb16_insn(0x4778), // bx pc
4657 Insn_template::thumb16_insn(0x46c0), // nop
4658 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4659 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4660 // dcd R_ARM_ABS32(X)
4663 // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4664 // one, when the destination is close enough.
4665 static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4667 Insn_template::thumb16_insn(0x4778), // bx pc
4668 Insn_template::thumb16_insn(0x46c0), // nop
4669 Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8)
4672 // ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use
4673 // blx to reach the stub if necessary.
4674 static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4676 Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc]
4677 Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip
4678 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4679 // dcd R_ARM_REL32(X-4)
4682 // ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use
4683 // blx to reach the stub if necessary. We can not add into pc;
4684 // it is not guaranteed to mode switch (different in ARMv6 and
4685 // ARMv7).
4686 static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4688 Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4]
4689 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4690 Insn_template::arm_insn(0xe12fff1c), // bx ip
4691 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4692 // dcd R_ARM_REL32(X)
4695 // V4T ARM -> ARM long branch stub, PIC.
4696 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4698 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4699 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4700 Insn_template::arm_insn(0xe12fff1c), // bx ip
4701 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4702 // dcd R_ARM_REL32(X)
4705 // V4T Thumb -> ARM long branch stub, PIC.
4706 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4708 Insn_template::thumb16_insn(0x4778), // bx pc
4709 Insn_template::thumb16_insn(0x46c0), // nop
4710 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4711 Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc
4712 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4713 // dcd R_ARM_REL32(X)
4716 // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4717 // architectures.
4718 static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4720 Insn_template::thumb16_insn(0xb401), // push {r0}
4721 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4722 Insn_template::thumb16_insn(0x46fc), // mov ip, pc
4723 Insn_template::thumb16_insn(0x4484), // add ip, r0
4724 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4725 Insn_template::thumb16_insn(0x4760), // bx ip
4726 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4727 // dcd R_ARM_REL32(X)
4730 // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4731 // allowed.
4732 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4734 Insn_template::thumb16_insn(0x4778), // bx pc
4735 Insn_template::thumb16_insn(0x46c0), // nop
4736 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4737 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4738 Insn_template::arm_insn(0xe12fff1c), // bx ip
4739 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4740 // dcd R_ARM_REL32(X)
4743 // Cortex-A8 erratum-workaround stubs.
4745 // Stub used for conditional branches (which may be beyond +/-1MB away,
4746 // so we can't use a conditional branch to reach this stub).
4748 // original code:
4750 // b<cond> X
4751 // after:
4753 static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4755 Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true
4756 Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after
4757 Insn_template::thumb32_b_insn(0xf000b800, -4) // true:
4758 // b.w X
4761 // Stub used for b.w and bl.w instructions.
4763 static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4765 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4768 static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4770 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4773 // Stub used for Thumb-2 blx.w instructions. We modified the original blx.w
4774 // instruction (which switches to ARM mode) to point to this stub. Jump to
4775 // the real destination using an ARM-mode branch.
4776 static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4778 Insn_template::arm_rel_insn(0xea000000, -8) // b dest
4781 // Stub used to provide an interworking for R_ARM_V4BX relocation
4782 // (bx r[n] instruction).
4783 static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4785 Insn_template::arm_insn(0xe3100001), // tst r<n>, #1
4786 Insn_template::arm_insn(0x01a0f000), // moveq pc, r<n>
4787 Insn_template::arm_insn(0xe12fff10) // bx r<n>
4790 // Fill in the stub template look-up table. Stub templates are constructed
4791 // per instance of Stub_factory for fast look-up without locking
4792 // in a thread-enabled environment.
4794 this->stub_templates_[arm_stub_none] =
4795 new Stub_template(arm_stub_none, NULL, 0);
4797 #define DEF_STUB(x) \
4798 do \
4800 size_t array_size \
4801 = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4802 Stub_type type = arm_stub_##x; \
4803 this->stub_templates_[type] = \
4804 new Stub_template(type, elf32_arm_stub_##x, array_size); \
4806 while (0);
4808 DEF_STUBS
4809 #undef DEF_STUB
4812 // Stub_table methods.
4814 // Removel all Cortex-A8 stub.
4816 template<bool big_endian>
4817 void
4818 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4820 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4821 p != this->cortex_a8_stubs_.end();
4822 ++p)
4823 delete p->second;
4824 this->cortex_a8_stubs_.clear();
4827 // Relocate one stub. This is a helper for Stub_table::relocate_stubs().
4829 template<bool big_endian>
4830 void
4831 Stub_table<big_endian>::relocate_stub(
4832 Stub* stub,
4833 const Relocate_info<32, big_endian>* relinfo,
4834 Target_arm<big_endian>* arm_target,
4835 Output_section* output_section,
4836 unsigned char* view,
4837 Arm_address address,
4838 section_size_type view_size)
4840 const Stub_template* stub_template = stub->stub_template();
4841 if (stub_template->reloc_count() != 0)
4843 // Adjust view to cover the stub only.
4844 section_size_type offset = stub->offset();
4845 section_size_type stub_size = stub_template->size();
4846 gold_assert(offset + stub_size <= view_size);
4848 arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4849 address + offset, stub_size);
4853 // Relocate all stubs in this stub table.
4855 template<bool big_endian>
4856 void
4857 Stub_table<big_endian>::relocate_stubs(
4858 const Relocate_info<32, big_endian>* relinfo,
4859 Target_arm<big_endian>* arm_target,
4860 Output_section* output_section,
4861 unsigned char* view,
4862 Arm_address address,
4863 section_size_type view_size)
4865 // If we are passed a view bigger than the stub table's. we need to
4866 // adjust the view.
4867 gold_assert(address == this->address()
4868 && (view_size
4869 == static_cast<section_size_type>(this->data_size())));
4871 // Relocate all relocation stubs.
4872 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4873 p != this->reloc_stubs_.end();
4874 ++p)
4875 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4876 address, view_size);
4878 // Relocate all Cortex-A8 stubs.
4879 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4880 p != this->cortex_a8_stubs_.end();
4881 ++p)
4882 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4883 address, view_size);
4885 // Relocate all ARM V4BX stubs.
4886 for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4887 p != this->arm_v4bx_stubs_.end();
4888 ++p)
4890 if (*p != NULL)
4891 this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4892 address, view_size);
4896 // Write out the stubs to file.
4898 template<bool big_endian>
4899 void
4900 Stub_table<big_endian>::do_write(Output_file* of)
4902 off_t offset = this->offset();
4903 const section_size_type oview_size =
4904 convert_to_section_size_type(this->data_size());
4905 unsigned char* const oview = of->get_output_view(offset, oview_size);
4907 // Write relocation stubs.
4908 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4909 p != this->reloc_stubs_.end();
4910 ++p)
4912 Reloc_stub* stub = p->second;
4913 Arm_address address = this->address() + stub->offset();
4914 gold_assert(address
4915 == align_address(address,
4916 stub->stub_template()->alignment()));
4917 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4918 big_endian);
4921 // Write Cortex-A8 stubs.
4922 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4923 p != this->cortex_a8_stubs_.end();
4924 ++p)
4926 Cortex_a8_stub* stub = p->second;
4927 Arm_address address = this->address() + stub->offset();
4928 gold_assert(address
4929 == align_address(address,
4930 stub->stub_template()->alignment()));
4931 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4932 big_endian);
4935 // Write ARM V4BX relocation stubs.
4936 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4937 p != this->arm_v4bx_stubs_.end();
4938 ++p)
4940 if (*p == NULL)
4941 continue;
4943 Arm_address address = this->address() + (*p)->offset();
4944 gold_assert(address
4945 == align_address(address,
4946 (*p)->stub_template()->alignment()));
4947 (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4948 big_endian);
4951 of->write_output_view(this->offset(), oview_size, oview);
4954 // Update the data size and address alignment of the stub table at the end
4955 // of a relaxation pass. Return true if either the data size or the
4956 // alignment changed in this relaxation pass.
4958 template<bool big_endian>
4959 bool
4960 Stub_table<big_endian>::update_data_size_and_addralign()
4962 // Go over all stubs in table to compute data size and address alignment.
4963 off_t size = this->reloc_stubs_size_;
4964 unsigned addralign = this->reloc_stubs_addralign_;
4966 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4967 p != this->cortex_a8_stubs_.end();
4968 ++p)
4970 const Stub_template* stub_template = p->second->stub_template();
4971 addralign = std::max(addralign, stub_template->alignment());
4972 size = (align_address(size, stub_template->alignment())
4973 + stub_template->size());
4976 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4977 p != this->arm_v4bx_stubs_.end();
4978 ++p)
4980 if (*p == NULL)
4981 continue;
4983 const Stub_template* stub_template = (*p)->stub_template();
4984 addralign = std::max(addralign, stub_template->alignment());
4985 size = (align_address(size, stub_template->alignment())
4986 + stub_template->size());
4989 // Check if either data size or alignment changed in this pass.
4990 // Update prev_data_size_ and prev_addralign_. These will be used
4991 // as the current data size and address alignment for the next pass.
4992 bool changed = size != this->prev_data_size_;
4993 this->prev_data_size_ = size;
4995 if (addralign != this->prev_addralign_)
4996 changed = true;
4997 this->prev_addralign_ = addralign;
4999 return changed;
5002 // Finalize the stubs. This sets the offsets of the stubs within the stub
5003 // table. It also marks all input sections needing Cortex-A8 workaround.
5005 template<bool big_endian>
5006 void
5007 Stub_table<big_endian>::finalize_stubs()
5009 off_t off = this->reloc_stubs_size_;
5010 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5011 p != this->cortex_a8_stubs_.end();
5012 ++p)
5014 Cortex_a8_stub* stub = p->second;
5015 const Stub_template* stub_template = stub->stub_template();
5016 uint64_t stub_addralign = stub_template->alignment();
5017 off = align_address(off, stub_addralign);
5018 stub->set_offset(off);
5019 off += stub_template->size();
5021 // Mark input section so that we can determine later if a code section
5022 // needs the Cortex-A8 workaround quickly.
5023 Arm_relobj<big_endian>* arm_relobj =
5024 Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5025 arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5028 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5029 p != this->arm_v4bx_stubs_.end();
5030 ++p)
5032 if (*p == NULL)
5033 continue;
5035 const Stub_template* stub_template = (*p)->stub_template();
5036 uint64_t stub_addralign = stub_template->alignment();
5037 off = align_address(off, stub_addralign);
5038 (*p)->set_offset(off);
5039 off += stub_template->size();
5042 gold_assert(off <= this->prev_data_size_);
5045 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5046 // and VIEW_ADDRESS + VIEW_SIZE - 1. VIEW points to the mapped address
5047 // of the address range seen by the linker.
5049 template<bool big_endian>
5050 void
5051 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5052 Target_arm<big_endian>* arm_target,
5053 unsigned char* view,
5054 Arm_address view_address,
5055 section_size_type view_size)
5057 // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5058 for (Cortex_a8_stub_list::const_iterator p =
5059 this->cortex_a8_stubs_.lower_bound(view_address);
5060 ((p != this->cortex_a8_stubs_.end())
5061 && (p->first < (view_address + view_size)));
5062 ++p)
5064 // We do not store the THUMB bit in the LSB of either the branch address
5065 // or the stub offset. There is no need to strip the LSB.
5066 Arm_address branch_address = p->first;
5067 const Cortex_a8_stub* stub = p->second;
5068 Arm_address stub_address = this->address() + stub->offset();
5070 // Offset of the branch instruction relative to this view.
5071 section_size_type offset =
5072 convert_to_section_size_type(branch_address - view_address);
5073 gold_assert((offset + 4) <= view_size);
5075 arm_target->apply_cortex_a8_workaround(stub, stub_address,
5076 view + offset, branch_address);
5080 // Arm_input_section methods.
5082 // Initialize an Arm_input_section.
5084 template<bool big_endian>
5085 void
5086 Arm_input_section<big_endian>::init()
5088 Relobj* relobj = this->relobj();
5089 unsigned int shndx = this->shndx();
5091 // Cache these to speed up size and alignment queries. It is too slow
5092 // to call section_addraglin and section_size every time.
5093 this->original_addralign_ =
5094 convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5095 this->original_size_ =
5096 convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5098 // We want to make this look like the original input section after
5099 // output sections are finalized.
5100 Output_section* os = relobj->output_section(shndx);
5101 off_t offset = relobj->output_section_offset(shndx);
5102 gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5103 this->set_address(os->address() + offset);
5104 this->set_file_offset(os->offset() + offset);
5106 this->set_current_data_size(this->original_size_);
5107 this->finalize_data_size();
5110 template<bool big_endian>
5111 void
5112 Arm_input_section<big_endian>::do_write(Output_file* of)
5114 // We have to write out the original section content.
5115 section_size_type section_size;
5116 const unsigned char* section_contents =
5117 this->relobj()->section_contents(this->shndx(), &section_size, false);
5118 of->write(this->offset(), section_contents, section_size);
5120 // If this owns a stub table and it is not empty, write it.
5121 if (this->is_stub_table_owner() && !this->stub_table_->empty())
5122 this->stub_table_->write(of);
5125 // Finalize data size.
5127 template<bool big_endian>
5128 void
5129 Arm_input_section<big_endian>::set_final_data_size()
5131 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5133 if (this->is_stub_table_owner())
5135 this->stub_table_->finalize_data_size();
5136 off = align_address(off, this->stub_table_->addralign());
5137 off += this->stub_table_->data_size();
5139 this->set_data_size(off);
5142 // Reset address and file offset.
5144 template<bool big_endian>
5145 void
5146 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5148 // Size of the original input section contents.
5149 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5151 // If this is a stub table owner, account for the stub table size.
5152 if (this->is_stub_table_owner())
5154 Stub_table<big_endian>* stub_table = this->stub_table_;
5156 // Reset the stub table's address and file offset. The
5157 // current data size for child will be updated after that.
5158 stub_table_->reset_address_and_file_offset();
5159 off = align_address(off, stub_table_->addralign());
5160 off += stub_table->current_data_size();
5163 this->set_current_data_size(off);
5166 // Arm_exidx_cantunwind methods.
5168 // Write this to Output file OF for a fixed endianness.
5170 template<bool big_endian>
5171 void
5172 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5174 off_t offset = this->offset();
5175 const section_size_type oview_size = 8;
5176 unsigned char* const oview = of->get_output_view(offset, oview_size);
5178 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5179 Valtype* wv = reinterpret_cast<Valtype*>(oview);
5181 Output_section* os = this->relobj_->output_section(this->shndx_);
5182 gold_assert(os != NULL);
5184 Arm_relobj<big_endian>* arm_relobj =
5185 Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5186 Arm_address output_offset =
5187 arm_relobj->get_output_section_offset(this->shndx_);
5188 Arm_address section_start;
5189 if (output_offset != Arm_relobj<big_endian>::invalid_address)
5190 section_start = os->address() + output_offset;
5191 else
5193 // Currently this only happens for a relaxed section.
5194 const Output_relaxed_input_section* poris =
5195 os->find_relaxed_input_section(this->relobj_, this->shndx_);
5196 gold_assert(poris != NULL);
5197 section_start = poris->address();
5200 // We always append this to the end of an EXIDX section.
5201 Arm_address output_address =
5202 section_start + this->relobj_->section_size(this->shndx_);
5204 // Write out the entry. The first word either points to the beginning
5205 // or after the end of a text section. The second word is the special
5206 // EXIDX_CANTUNWIND value.
5207 uint32_t prel31_offset = output_address - this->address();
5208 if (utils::has_overflow<31>(offset))
5209 gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5210 elfcpp::Swap<32, big_endian>::writeval(wv, prel31_offset & 0x7fffffffU);
5211 elfcpp::Swap<32, big_endian>::writeval(wv + 1, elfcpp::EXIDX_CANTUNWIND);
5213 of->write_output_view(this->offset(), oview_size, oview);
5216 // Arm_exidx_merged_section methods.
5218 // Constructor for Arm_exidx_merged_section.
5219 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5220 // SECTION_OFFSET_MAP points to a section offset map describing how
5221 // parts of the input section are mapped to output. DELETED_BYTES is
5222 // the number of bytes deleted from the EXIDX input section.
5224 Arm_exidx_merged_section::Arm_exidx_merged_section(
5225 const Arm_exidx_input_section& exidx_input_section,
5226 const Arm_exidx_section_offset_map& section_offset_map,
5227 uint32_t deleted_bytes)
5228 : Output_relaxed_input_section(exidx_input_section.relobj(),
5229 exidx_input_section.shndx(),
5230 exidx_input_section.addralign()),
5231 exidx_input_section_(exidx_input_section),
5232 section_offset_map_(section_offset_map)
5234 // Fix size here so that we do not need to implement set_final_data_size.
5235 this->set_data_size(exidx_input_section.size() - deleted_bytes);
5236 this->fix_data_size();
5239 // Given an input OBJECT, an input section index SHNDX within that
5240 // object, and an OFFSET relative to the start of that input
5241 // section, return whether or not the corresponding offset within
5242 // the output section is known. If this function returns true, it
5243 // sets *POUTPUT to the output offset. The value -1 indicates that
5244 // this input offset is being discarded.
5246 bool
5247 Arm_exidx_merged_section::do_output_offset(
5248 const Relobj* relobj,
5249 unsigned int shndx,
5250 section_offset_type offset,
5251 section_offset_type* poutput) const
5253 // We only handle offsets for the original EXIDX input section.
5254 if (relobj != this->exidx_input_section_.relobj()
5255 || shndx != this->exidx_input_section_.shndx())
5256 return false;
5258 section_offset_type section_size =
5259 convert_types<section_offset_type>(this->exidx_input_section_.size());
5260 if (offset < 0 || offset >= section_size)
5261 // Input offset is out of valid range.
5262 *poutput = -1;
5263 else
5265 // We need to look up the section offset map to determine the output
5266 // offset. Find the reference point in map that is first offset
5267 // bigger than or equal to this offset.
5268 Arm_exidx_section_offset_map::const_iterator p =
5269 this->section_offset_map_.lower_bound(offset);
5271 // The section offset maps are build such that this should not happen if
5272 // input offset is in the valid range.
5273 gold_assert(p != this->section_offset_map_.end());
5275 // We need to check if this is dropped.
5276 section_offset_type ref = p->first;
5277 section_offset_type mapped_ref = p->second;
5279 if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5280 // Offset is present in output.
5281 *poutput = mapped_ref + (offset - ref);
5282 else
5283 // Offset is discarded owing to EXIDX entry merging.
5284 *poutput = -1;
5287 return true;
5290 // Write this to output file OF.
5292 void
5293 Arm_exidx_merged_section::do_write(Output_file* of)
5295 // If we retain or discard the whole EXIDX input section, we would
5296 // not be here.
5297 gold_assert(this->data_size() != this->exidx_input_section_.size()
5298 && this->data_size() != 0);
5300 off_t offset = this->offset();
5301 const section_size_type oview_size = this->data_size();
5302 unsigned char* const oview = of->get_output_view(offset, oview_size);
5304 Output_section* os = this->relobj()->output_section(this->shndx());
5305 gold_assert(os != NULL);
5307 // Get contents of EXIDX input section.
5308 section_size_type section_size;
5309 const unsigned char* section_contents =
5310 this->relobj()->section_contents(this->shndx(), &section_size, false);
5311 gold_assert(section_size == this->exidx_input_section_.size());
5313 // Go over spans of input offsets and write only those that are not
5314 // discarded.
5315 section_offset_type in_start = 0;
5316 section_offset_type out_start = 0;
5317 for(Arm_exidx_section_offset_map::const_iterator p =
5318 this->section_offset_map_.begin();
5319 p != this->section_offset_map_.end();
5320 ++p)
5322 section_offset_type in_end = p->first;
5323 gold_assert(in_end >= in_start);
5324 section_offset_type out_end = p->second;
5325 size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5326 if (out_end != -1)
5328 size_t out_chunk_size =
5329 convert_types<size_t>(out_end - out_start + 1);
5330 gold_assert(out_chunk_size == in_chunk_size);
5331 memcpy(oview + out_start, section_contents + in_start,
5332 out_chunk_size);
5333 out_start += out_chunk_size;
5335 in_start += in_chunk_size;
5338 gold_assert(convert_to_section_size_type(out_start) == oview_size);
5339 of->write_output_view(this->offset(), oview_size, oview);
5342 // Arm_exidx_fixup methods.
5344 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5345 // is not an EXIDX_CANTUNWIND entry already. The new EXIDX_CANTUNWIND entry
5346 // points to the end of the last seen EXIDX section.
5348 void
5349 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5351 if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5352 && this->last_input_section_ != NULL)
5354 Relobj* relobj = this->last_input_section_->relobj();
5355 unsigned int text_shndx = this->last_input_section_->link();
5356 Arm_exidx_cantunwind* cantunwind =
5357 new Arm_exidx_cantunwind(relobj, text_shndx);
5358 this->exidx_output_section_->add_output_section_data(cantunwind);
5359 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5363 // Process an EXIDX section entry in input. Return whether this entry
5364 // can be deleted in the output. SECOND_WORD in the second word of the
5365 // EXIDX entry.
5367 bool
5368 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5370 bool delete_entry;
5371 if (second_word == elfcpp::EXIDX_CANTUNWIND)
5373 // Merge if previous entry is also an EXIDX_CANTUNWIND.
5374 delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5375 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5377 else if ((second_word & 0x80000000) != 0)
5379 // Inlined unwinding data. Merge if equal to previous.
5380 delete_entry = (merge_exidx_entries_
5381 && this->last_unwind_type_ == UT_INLINED_ENTRY
5382 && this->last_inlined_entry_ == second_word);
5383 this->last_unwind_type_ = UT_INLINED_ENTRY;
5384 this->last_inlined_entry_ = second_word;
5386 else
5388 // Normal table entry. In theory we could merge these too,
5389 // but duplicate entries are likely to be much less common.
5390 delete_entry = false;
5391 this->last_unwind_type_ = UT_NORMAL_ENTRY;
5393 return delete_entry;
5396 // Update the current section offset map during EXIDX section fix-up.
5397 // If there is no map, create one. INPUT_OFFSET is the offset of a
5398 // reference point, DELETED_BYTES is the number of deleted by in the
5399 // section so far. If DELETE_ENTRY is true, the reference point and
5400 // all offsets after the previous reference point are discarded.
5402 void
5403 Arm_exidx_fixup::update_offset_map(
5404 section_offset_type input_offset,
5405 section_size_type deleted_bytes,
5406 bool delete_entry)
5408 if (this->section_offset_map_ == NULL)
5409 this->section_offset_map_ = new Arm_exidx_section_offset_map();
5410 section_offset_type output_offset;
5411 if (delete_entry)
5412 output_offset = Arm_exidx_input_section::invalid_offset;
5413 else
5414 output_offset = input_offset - deleted_bytes;
5415 (*this->section_offset_map_)[input_offset] = output_offset;
5418 // Process EXIDX_INPUT_SECTION for EXIDX entry merging. Return the number of
5419 // bytes deleted. If some entries are merged, also store a pointer to a newly
5420 // created Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP. The
5421 // caller owns the map and is responsible for releasing it after use.
5423 template<bool big_endian>
5424 uint32_t
5425 Arm_exidx_fixup::process_exidx_section(
5426 const Arm_exidx_input_section* exidx_input_section,
5427 Arm_exidx_section_offset_map** psection_offset_map)
5429 Relobj* relobj = exidx_input_section->relobj();
5430 unsigned shndx = exidx_input_section->shndx();
5431 section_size_type section_size;
5432 const unsigned char* section_contents =
5433 relobj->section_contents(shndx, &section_size, false);
5435 if ((section_size % 8) != 0)
5437 // Something is wrong with this section. Better not touch it.
5438 gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5439 relobj->name().c_str(), shndx);
5440 this->last_input_section_ = exidx_input_section;
5441 this->last_unwind_type_ = UT_NONE;
5442 return 0;
5445 uint32_t deleted_bytes = 0;
5446 bool prev_delete_entry = false;
5447 gold_assert(this->section_offset_map_ == NULL);
5449 for (section_size_type i = 0; i < section_size; i += 8)
5451 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5452 const Valtype* wv =
5453 reinterpret_cast<const Valtype*>(section_contents + i + 4);
5454 uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5456 bool delete_entry = this->process_exidx_entry(second_word);
5458 // Entry deletion causes changes in output offsets. We use a std::map
5459 // to record these. And entry (x, y) means input offset x
5460 // is mapped to output offset y. If y is invalid_offset, then x is
5461 // dropped in the output. Because of the way std::map::lower_bound
5462 // works, we record the last offset in a region w.r.t to keeping or
5463 // dropping. If there is no entry (x0, y0) for an input offset x0,
5464 // the output offset y0 of it is determined by the output offset y1 of
5465 // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5466 // in the map. If y1 is not -1, then y0 = y1 + x0 - x1. Othewise, y1
5467 // y0 is also -1.
5468 if (delete_entry != prev_delete_entry && i != 0)
5469 this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5471 // Update total deleted bytes for this entry.
5472 if (delete_entry)
5473 deleted_bytes += 8;
5475 prev_delete_entry = delete_entry;
5478 // If section offset map is not NULL, make an entry for the end of
5479 // section.
5480 if (this->section_offset_map_ != NULL)
5481 update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5483 *psection_offset_map = this->section_offset_map_;
5484 this->section_offset_map_ = NULL;
5485 this->last_input_section_ = exidx_input_section;
5487 // Set the first output text section so that we can link the EXIDX output
5488 // section to it. Ignore any EXIDX input section that is completely merged.
5489 if (this->first_output_text_section_ == NULL
5490 && deleted_bytes != section_size)
5492 unsigned int link = exidx_input_section->link();
5493 Output_section* os = relobj->output_section(link);
5494 gold_assert(os != NULL);
5495 this->first_output_text_section_ = os;
5498 return deleted_bytes;
5501 // Arm_output_section methods.
5503 // Create a stub group for input sections from BEGIN to END. OWNER
5504 // points to the input section to be the owner a new stub table.
5506 template<bool big_endian>
5507 void
5508 Arm_output_section<big_endian>::create_stub_group(
5509 Input_section_list::const_iterator begin,
5510 Input_section_list::const_iterator end,
5511 Input_section_list::const_iterator owner,
5512 Target_arm<big_endian>* target,
5513 std::vector<Output_relaxed_input_section*>* new_relaxed_sections)
5515 // We use a different kind of relaxed section in an EXIDX section.
5516 // The static casting from Output_relaxed_input_section to
5517 // Arm_input_section is invalid in an EXIDX section. We are okay
5518 // because we should not be calling this for an EXIDX section.
5519 gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5521 // Currently we convert ordinary input sections into relaxed sections only
5522 // at this point but we may want to support creating relaxed input section
5523 // very early. So we check here to see if owner is already a relaxed
5524 // section.
5526 Arm_input_section<big_endian>* arm_input_section;
5527 if (owner->is_relaxed_input_section())
5529 arm_input_section =
5530 Arm_input_section<big_endian>::as_arm_input_section(
5531 owner->relaxed_input_section());
5533 else
5535 gold_assert(owner->is_input_section());
5536 // Create a new relaxed input section.
5537 arm_input_section =
5538 target->new_arm_input_section(owner->relobj(), owner->shndx());
5539 new_relaxed_sections->push_back(arm_input_section);
5542 // Create a stub table.
5543 Stub_table<big_endian>* stub_table =
5544 target->new_stub_table(arm_input_section);
5546 arm_input_section->set_stub_table(stub_table);
5548 Input_section_list::const_iterator p = begin;
5549 Input_section_list::const_iterator prev_p;
5551 // Look for input sections or relaxed input sections in [begin ... end].
5554 if (p->is_input_section() || p->is_relaxed_input_section())
5556 // The stub table information for input sections live
5557 // in their objects.
5558 Arm_relobj<big_endian>* arm_relobj =
5559 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5560 arm_relobj->set_stub_table(p->shndx(), stub_table);
5562 prev_p = p++;
5564 while (prev_p != end);
5567 // Group input sections for stub generation. GROUP_SIZE is roughly the limit
5568 // of stub groups. We grow a stub group by adding input section until the
5569 // size is just below GROUP_SIZE. The last input section will be converted
5570 // into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5571 // input section after the stub table, effectively double the group size.
5573 // This is similar to the group_sections() function in elf32-arm.c but is
5574 // implemented differently.
5576 template<bool big_endian>
5577 void
5578 Arm_output_section<big_endian>::group_sections(
5579 section_size_type group_size,
5580 bool stubs_always_after_branch,
5581 Target_arm<big_endian>* target)
5583 // We only care about sections containing code.
5584 if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
5585 return;
5587 // States for grouping.
5588 typedef enum
5590 // No group is being built.
5591 NO_GROUP,
5592 // A group is being built but the stub table is not found yet.
5593 // We keep group a stub group until the size is just under GROUP_SIZE.
5594 // The last input section in the group will be used as the stub table.
5595 FINDING_STUB_SECTION,
5596 // A group is being built and we have already found a stub table.
5597 // We enter this state to grow a stub group by adding input section
5598 // after the stub table. This effectively doubles the group size.
5599 HAS_STUB_SECTION
5600 } State;
5602 // Any newly created relaxed sections are stored here.
5603 std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5605 State state = NO_GROUP;
5606 section_size_type off = 0;
5607 section_size_type group_begin_offset = 0;
5608 section_size_type group_end_offset = 0;
5609 section_size_type stub_table_end_offset = 0;
5610 Input_section_list::const_iterator group_begin =
5611 this->input_sections().end();
5612 Input_section_list::const_iterator stub_table =
5613 this->input_sections().end();
5614 Input_section_list::const_iterator group_end = this->input_sections().end();
5615 for (Input_section_list::const_iterator p = this->input_sections().begin();
5616 p != this->input_sections().end();
5617 ++p)
5619 section_size_type section_begin_offset =
5620 align_address(off, p->addralign());
5621 section_size_type section_end_offset =
5622 section_begin_offset + p->data_size();
5624 // Check to see if we should group the previously seens sections.
5625 switch (state)
5627 case NO_GROUP:
5628 break;
5630 case FINDING_STUB_SECTION:
5631 // Adding this section makes the group larger than GROUP_SIZE.
5632 if (section_end_offset - group_begin_offset >= group_size)
5634 if (stubs_always_after_branch)
5636 gold_assert(group_end != this->input_sections().end());
5637 this->create_stub_group(group_begin, group_end, group_end,
5638 target, &new_relaxed_sections);
5639 state = NO_GROUP;
5641 else
5643 // But wait, there's more! Input sections up to
5644 // stub_group_size bytes after the stub table can be
5645 // handled by it too.
5646 state = HAS_STUB_SECTION;
5647 stub_table = group_end;
5648 stub_table_end_offset = group_end_offset;
5651 break;
5653 case HAS_STUB_SECTION:
5654 // Adding this section makes the post stub-section group larger
5655 // than GROUP_SIZE.
5656 if (section_end_offset - stub_table_end_offset >= group_size)
5658 gold_assert(group_end != this->input_sections().end());
5659 this->create_stub_group(group_begin, group_end, stub_table,
5660 target, &new_relaxed_sections);
5661 state = NO_GROUP;
5663 break;
5665 default:
5666 gold_unreachable();
5669 // If we see an input section and currently there is no group, start
5670 // a new one. Skip any empty sections.
5671 if ((p->is_input_section() || p->is_relaxed_input_section())
5672 && (p->relobj()->section_size(p->shndx()) != 0))
5674 if (state == NO_GROUP)
5676 state = FINDING_STUB_SECTION;
5677 group_begin = p;
5678 group_begin_offset = section_begin_offset;
5681 // Keep track of the last input section seen.
5682 group_end = p;
5683 group_end_offset = section_end_offset;
5686 off = section_end_offset;
5689 // Create a stub group for any ungrouped sections.
5690 if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5692 gold_assert(group_end != this->input_sections().end());
5693 this->create_stub_group(group_begin, group_end,
5694 (state == FINDING_STUB_SECTION
5695 ? group_end
5696 : stub_table),
5697 target, &new_relaxed_sections);
5700 // Convert input section into relaxed input section in a batch.
5701 if (!new_relaxed_sections.empty())
5702 this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5704 // Update the section offsets
5705 for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5707 Arm_relobj<big_endian>* arm_relobj =
5708 Arm_relobj<big_endian>::as_arm_relobj(
5709 new_relaxed_sections[i]->relobj());
5710 unsigned int shndx = new_relaxed_sections[i]->shndx();
5711 // Tell Arm_relobj that this input section is converted.
5712 arm_relobj->convert_input_section_to_relaxed_section(shndx);
5716 // Append non empty text sections in this to LIST in ascending
5717 // order of their position in this.
5719 template<bool big_endian>
5720 void
5721 Arm_output_section<big_endian>::append_text_sections_to_list(
5722 Text_section_list* list)
5724 gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5726 for (Input_section_list::const_iterator p = this->input_sections().begin();
5727 p != this->input_sections().end();
5728 ++p)
5730 // We only care about plain or relaxed input sections. We also
5731 // ignore any merged sections.
5732 if ((p->is_input_section() || p->is_relaxed_input_section())
5733 && p->data_size() != 0)
5734 list->push_back(Text_section_list::value_type(p->relobj(),
5735 p->shndx()));
5739 template<bool big_endian>
5740 void
5741 Arm_output_section<big_endian>::fix_exidx_coverage(
5742 Layout* layout,
5743 const Text_section_list& sorted_text_sections,
5744 Symbol_table* symtab,
5745 bool merge_exidx_entries)
5747 // We should only do this for the EXIDX output section.
5748 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5750 // We don't want the relaxation loop to undo these changes, so we discard
5751 // the current saved states and take another one after the fix-up.
5752 this->discard_states();
5754 // Remove all input sections.
5755 uint64_t address = this->address();
5756 typedef std::list<Output_section::Input_section> Input_section_list;
5757 Input_section_list input_sections;
5758 this->reset_address_and_file_offset();
5759 this->get_input_sections(address, std::string(""), &input_sections);
5761 if (!this->input_sections().empty())
5762 gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5764 // Go through all the known input sections and record them.
5765 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5766 typedef Unordered_map<Section_id, const Output_section::Input_section*,
5767 Section_id_hash> Text_to_exidx_map;
5768 Text_to_exidx_map text_to_exidx_map;
5769 for (Input_section_list::const_iterator p = input_sections.begin();
5770 p != input_sections.end();
5771 ++p)
5773 // This should never happen. At this point, we should only see
5774 // plain EXIDX input sections.
5775 gold_assert(!p->is_relaxed_input_section());
5776 text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5779 Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5781 // Go over the sorted text sections.
5782 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5783 Section_id_set processed_input_sections;
5784 for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5785 p != sorted_text_sections.end();
5786 ++p)
5788 Relobj* relobj = p->first;
5789 unsigned int shndx = p->second;
5791 Arm_relobj<big_endian>* arm_relobj =
5792 Arm_relobj<big_endian>::as_arm_relobj(relobj);
5793 const Arm_exidx_input_section* exidx_input_section =
5794 arm_relobj->exidx_input_section_by_link(shndx);
5796 // If this text section has no EXIDX section or if the EXIDX section
5797 // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5798 // of the last seen EXIDX section.
5799 if (exidx_input_section == NULL || exidx_input_section->has_errors())
5801 exidx_fixup.add_exidx_cantunwind_as_needed();
5802 continue;
5805 Relobj* exidx_relobj = exidx_input_section->relobj();
5806 unsigned int exidx_shndx = exidx_input_section->shndx();
5807 Section_id sid(exidx_relobj, exidx_shndx);
5808 Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5809 if (iter == text_to_exidx_map.end())
5811 // This is odd. We have not seen this EXIDX input section before.
5812 // We cannot do fix-up. If we saw a SECTIONS clause in a script,
5813 // issue a warning instead. We assume the user knows what he
5814 // or she is doing. Otherwise, this is an error.
5815 if (layout->script_options()->saw_sections_clause())
5816 gold_warning(_("unwinding may not work because EXIDX input section"
5817 " %u of %s is not in EXIDX output section"),
5818 exidx_shndx, exidx_relobj->name().c_str());
5819 else
5820 gold_error(_("unwinding may not work because EXIDX input section"
5821 " %u of %s is not in EXIDX output section"),
5822 exidx_shndx, exidx_relobj->name().c_str());
5824 exidx_fixup.add_exidx_cantunwind_as_needed();
5825 continue;
5828 // Fix up coverage and append input section to output data list.
5829 Arm_exidx_section_offset_map* section_offset_map = NULL;
5830 uint32_t deleted_bytes =
5831 exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5832 &section_offset_map);
5834 if (deleted_bytes == exidx_input_section->size())
5836 // The whole EXIDX section got merged. Remove it from output.
5837 gold_assert(section_offset_map == NULL);
5838 exidx_relobj->set_output_section(exidx_shndx, NULL);
5840 // All local symbols defined in this input section will be dropped.
5841 // We need to adjust output local symbol count.
5842 arm_relobj->set_output_local_symbol_count_needs_update();
5844 else if (deleted_bytes > 0)
5846 // Some entries are merged. We need to convert this EXIDX input
5847 // section into a relaxed section.
5848 gold_assert(section_offset_map != NULL);
5849 Arm_exidx_merged_section* merged_section =
5850 new Arm_exidx_merged_section(*exidx_input_section,
5851 *section_offset_map, deleted_bytes);
5852 this->add_relaxed_input_section(merged_section);
5853 arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5855 // All local symbols defined in discarded portions of this input
5856 // section will be dropped. We need to adjust output local symbol
5857 // count.
5858 arm_relobj->set_output_local_symbol_count_needs_update();
5860 else
5862 // Just add back the EXIDX input section.
5863 gold_assert(section_offset_map == NULL);
5864 const Output_section::Input_section* pis = iter->second;
5865 gold_assert(pis->is_input_section());
5866 this->add_script_input_section(*pis);
5869 processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5872 // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5873 exidx_fixup.add_exidx_cantunwind_as_needed();
5875 // Remove any known EXIDX input sections that are not processed.
5876 for (Input_section_list::const_iterator p = input_sections.begin();
5877 p != input_sections.end();
5878 ++p)
5880 if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5881 == processed_input_sections.end())
5883 // We discard a known EXIDX section because its linked
5884 // text section has been folded by ICF. We also discard an
5885 // EXIDX section with error, the output does not matter in this
5886 // case. We do this to avoid triggering asserts.
5887 Arm_relobj<big_endian>* arm_relobj =
5888 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5889 const Arm_exidx_input_section* exidx_input_section =
5890 arm_relobj->exidx_input_section_by_shndx(p->shndx());
5891 gold_assert(exidx_input_section != NULL);
5892 if (!exidx_input_section->has_errors())
5894 unsigned int text_shndx = exidx_input_section->link();
5895 gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5898 // Remove this from link. We also need to recount the
5899 // local symbols.
5900 p->relobj()->set_output_section(p->shndx(), NULL);
5901 arm_relobj->set_output_local_symbol_count_needs_update();
5905 // Link exidx output section to the first seen output section and
5906 // set correct entry size.
5907 this->set_link_section(exidx_fixup.first_output_text_section());
5908 this->set_entsize(8);
5910 // Make changes permanent.
5911 this->save_states();
5912 this->set_section_offsets_need_adjustment();
5915 // Link EXIDX output sections to text output sections.
5917 template<bool big_endian>
5918 void
5919 Arm_output_section<big_endian>::set_exidx_section_link()
5921 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5922 if (!this->input_sections().empty())
5924 Input_section_list::const_iterator p = this->input_sections().begin();
5925 Arm_relobj<big_endian>* arm_relobj =
5926 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5927 unsigned exidx_shndx = p->shndx();
5928 const Arm_exidx_input_section* exidx_input_section =
5929 arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
5930 gold_assert(exidx_input_section != NULL);
5931 unsigned int text_shndx = exidx_input_section->link();
5932 Output_section* os = arm_relobj->output_section(text_shndx);
5933 this->set_link_section(os);
5937 // Arm_relobj methods.
5939 // Determine if an input section is scannable for stub processing. SHDR is
5940 // the header of the section and SHNDX is the section index. OS is the output
5941 // section for the input section and SYMTAB is the global symbol table used to
5942 // look up ICF information.
5944 template<bool big_endian>
5945 bool
5946 Arm_relobj<big_endian>::section_is_scannable(
5947 const elfcpp::Shdr<32, big_endian>& shdr,
5948 unsigned int shndx,
5949 const Output_section* os,
5950 const Symbol_table* symtab)
5952 // Skip any empty sections, unallocated sections or sections whose
5953 // type are not SHT_PROGBITS.
5954 if (shdr.get_sh_size() == 0
5955 || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
5956 || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
5957 return false;
5959 // Skip any discarded or ICF'ed sections.
5960 if (os == NULL || symtab->is_section_folded(this, shndx))
5961 return false;
5963 // If this requires special offset handling, check to see if it is
5964 // a relaxed section. If this is not, then it is a merged section that
5965 // we cannot handle.
5966 if (this->is_output_section_offset_invalid(shndx))
5968 const Output_relaxed_input_section* poris =
5969 os->find_relaxed_input_section(this, shndx);
5970 if (poris == NULL)
5971 return false;
5974 return true;
5977 // Determine if we want to scan the SHNDX-th section for relocation stubs.
5978 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
5980 template<bool big_endian>
5981 bool
5982 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
5983 const elfcpp::Shdr<32, big_endian>& shdr,
5984 const Relobj::Output_sections& out_sections,
5985 const Symbol_table* symtab,
5986 const unsigned char* pshdrs)
5988 unsigned int sh_type = shdr.get_sh_type();
5989 if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
5990 return false;
5992 // Ignore empty section.
5993 off_t sh_size = shdr.get_sh_size();
5994 if (sh_size == 0)
5995 return false;
5997 // Ignore reloc section with unexpected symbol table. The
5998 // error will be reported in the final link.
5999 if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6000 return false;
6002 unsigned int reloc_size;
6003 if (sh_type == elfcpp::SHT_REL)
6004 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6005 else
6006 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6008 // Ignore reloc section with unexpected entsize or uneven size.
6009 // The error will be reported in the final link.
6010 if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6011 return false;
6013 // Ignore reloc section with bad info. This error will be
6014 // reported in the final link.
6015 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6016 if (index >= this->shnum())
6017 return false;
6019 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6020 const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6021 return this->section_is_scannable(text_shdr, index,
6022 out_sections[index], symtab);
6025 // Return the output address of either a plain input section or a relaxed
6026 // input section. SHNDX is the section index. We define and use this
6027 // instead of calling Output_section::output_address because that is slow
6028 // for large output.
6030 template<bool big_endian>
6031 Arm_address
6032 Arm_relobj<big_endian>::simple_input_section_output_address(
6033 unsigned int shndx,
6034 Output_section* os)
6036 if (this->is_output_section_offset_invalid(shndx))
6038 const Output_relaxed_input_section* poris =
6039 os->find_relaxed_input_section(this, shndx);
6040 // We do not handle merged sections here.
6041 gold_assert(poris != NULL);
6042 return poris->address();
6044 else
6045 return os->address() + this->get_output_section_offset(shndx);
6048 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6049 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6051 template<bool big_endian>
6052 bool
6053 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6054 const elfcpp::Shdr<32, big_endian>& shdr,
6055 unsigned int shndx,
6056 Output_section* os,
6057 const Symbol_table* symtab)
6059 if (!this->section_is_scannable(shdr, shndx, os, symtab))
6060 return false;
6062 // If the section does not cross any 4K-boundaries, it does not need to
6063 // be scanned.
6064 Arm_address address = this->simple_input_section_output_address(shndx, os);
6065 if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6066 return false;
6068 return true;
6071 // Scan a section for Cortex-A8 workaround.
6073 template<bool big_endian>
6074 void
6075 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6076 const elfcpp::Shdr<32, big_endian>& shdr,
6077 unsigned int shndx,
6078 Output_section* os,
6079 Target_arm<big_endian>* arm_target)
6081 // Look for the first mapping symbol in this section. It should be
6082 // at (shndx, 0).
6083 Mapping_symbol_position section_start(shndx, 0);
6084 typename Mapping_symbols_info::const_iterator p =
6085 this->mapping_symbols_info_.lower_bound(section_start);
6087 // There are no mapping symbols for this section. Treat it as a data-only
6088 // section. Issue a warning if section is marked as containing
6089 // instructions.
6090 if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6092 if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6093 gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6094 "erratum because it has no mapping symbols."),
6095 shndx, this->name().c_str());
6096 return;
6099 Arm_address output_address =
6100 this->simple_input_section_output_address(shndx, os);
6102 // Get the section contents.
6103 section_size_type input_view_size = 0;
6104 const unsigned char* input_view =
6105 this->section_contents(shndx, &input_view_size, false);
6107 // We need to go through the mapping symbols to determine what to
6108 // scan. There are two reasons. First, we should look at THUMB code and
6109 // THUMB code only. Second, we only want to look at the 4K-page boundary
6110 // to speed up the scanning.
6112 while (p != this->mapping_symbols_info_.end()
6113 && p->first.first == shndx)
6115 typename Mapping_symbols_info::const_iterator next =
6116 this->mapping_symbols_info_.upper_bound(p->first);
6118 // Only scan part of a section with THUMB code.
6119 if (p->second == 't')
6121 // Determine the end of this range.
6122 section_size_type span_start =
6123 convert_to_section_size_type(p->first.second);
6124 section_size_type span_end;
6125 if (next != this->mapping_symbols_info_.end()
6126 && next->first.first == shndx)
6127 span_end = convert_to_section_size_type(next->first.second);
6128 else
6129 span_end = convert_to_section_size_type(shdr.get_sh_size());
6131 if (((span_start + output_address) & ~0xfffUL)
6132 != ((span_end + output_address - 1) & ~0xfffUL))
6134 arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6135 span_start, span_end,
6136 input_view,
6137 output_address);
6141 p = next;
6145 // Scan relocations for stub generation.
6147 template<bool big_endian>
6148 void
6149 Arm_relobj<big_endian>::scan_sections_for_stubs(
6150 Target_arm<big_endian>* arm_target,
6151 const Symbol_table* symtab,
6152 const Layout* layout)
6154 unsigned int shnum = this->shnum();
6155 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6157 // Read the section headers.
6158 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6159 shnum * shdr_size,
6160 true, true);
6162 // To speed up processing, we set up hash tables for fast lookup of
6163 // input offsets to output addresses.
6164 this->initialize_input_to_output_maps();
6166 const Relobj::Output_sections& out_sections(this->output_sections());
6168 Relocate_info<32, big_endian> relinfo;
6169 relinfo.symtab = symtab;
6170 relinfo.layout = layout;
6171 relinfo.object = this;
6173 // Do relocation stubs scanning.
6174 const unsigned char* p = pshdrs + shdr_size;
6175 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6177 const elfcpp::Shdr<32, big_endian> shdr(p);
6178 if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6179 pshdrs))
6181 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6182 Arm_address output_offset = this->get_output_section_offset(index);
6183 Arm_address output_address;
6184 if (output_offset != invalid_address)
6185 output_address = out_sections[index]->address() + output_offset;
6186 else
6188 // Currently this only happens for a relaxed section.
6189 const Output_relaxed_input_section* poris =
6190 out_sections[index]->find_relaxed_input_section(this, index);
6191 gold_assert(poris != NULL);
6192 output_address = poris->address();
6195 // Get the relocations.
6196 const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6197 shdr.get_sh_size(),
6198 true, false);
6200 // Get the section contents. This does work for the case in which
6201 // we modify the contents of an input section. We need to pass the
6202 // output view under such circumstances.
6203 section_size_type input_view_size = 0;
6204 const unsigned char* input_view =
6205 this->section_contents(index, &input_view_size, false);
6207 relinfo.reloc_shndx = i;
6208 relinfo.data_shndx = index;
6209 unsigned int sh_type = shdr.get_sh_type();
6210 unsigned int reloc_size;
6211 if (sh_type == elfcpp::SHT_REL)
6212 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6213 else
6214 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6216 Output_section* os = out_sections[index];
6217 arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6218 shdr.get_sh_size() / reloc_size,
6220 output_offset == invalid_address,
6221 input_view, output_address,
6222 input_view_size);
6226 // Do Cortex-A8 erratum stubs scanning. This has to be done for a section
6227 // after its relocation section, if there is one, is processed for
6228 // relocation stubs. Merging this loop with the one above would have been
6229 // complicated since we would have had to make sure that relocation stub
6230 // scanning is done first.
6231 if (arm_target->fix_cortex_a8())
6233 const unsigned char* p = pshdrs + shdr_size;
6234 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6236 const elfcpp::Shdr<32, big_endian> shdr(p);
6237 if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6238 out_sections[i],
6239 symtab))
6240 this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6241 arm_target);
6245 // After we've done the relocations, we release the hash tables,
6246 // since we no longer need them.
6247 this->free_input_to_output_maps();
6250 // Count the local symbols. The ARM backend needs to know if a symbol
6251 // is a THUMB function or not. For global symbols, it is easy because
6252 // the Symbol object keeps the ELF symbol type. For local symbol it is
6253 // harder because we cannot access this information. So we override the
6254 // do_count_local_symbol in parent and scan local symbols to mark
6255 // THUMB functions. This is not the most efficient way but I do not want to
6256 // slow down other ports by calling a per symbol targer hook inside
6257 // Sized_relobj<size, big_endian>::do_count_local_symbols.
6259 template<bool big_endian>
6260 void
6261 Arm_relobj<big_endian>::do_count_local_symbols(
6262 Stringpool_template<char>* pool,
6263 Stringpool_template<char>* dynpool)
6265 // We need to fix-up the values of any local symbols whose type are
6266 // STT_ARM_TFUNC.
6268 // Ask parent to count the local symbols.
6269 Sized_relobj<32, big_endian>::do_count_local_symbols(pool, dynpool);
6270 const unsigned int loccount = this->local_symbol_count();
6271 if (loccount == 0)
6272 return;
6274 // Intialize the thumb function bit-vector.
6275 std::vector<bool> empty_vector(loccount, false);
6276 this->local_symbol_is_thumb_function_.swap(empty_vector);
6278 // Read the symbol table section header.
6279 const unsigned int symtab_shndx = this->symtab_shndx();
6280 elfcpp::Shdr<32, big_endian>
6281 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6282 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6284 // Read the local symbols.
6285 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6286 gold_assert(loccount == symtabshdr.get_sh_info());
6287 off_t locsize = loccount * sym_size;
6288 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6289 locsize, true, true);
6291 // For mapping symbol processing, we need to read the symbol names.
6292 unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6293 if (strtab_shndx >= this->shnum())
6295 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6296 return;
6299 elfcpp::Shdr<32, big_endian>
6300 strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6301 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6303 this->error(_("symbol table name section has wrong type: %u"),
6304 static_cast<unsigned int>(strtabshdr.get_sh_type()));
6305 return;
6307 const char* pnames =
6308 reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6309 strtabshdr.get_sh_size(),
6310 false, false));
6312 // Loop over the local symbols and mark any local symbols pointing
6313 // to THUMB functions.
6315 // Skip the first dummy symbol.
6316 psyms += sym_size;
6317 typename Sized_relobj<32, big_endian>::Local_values* plocal_values =
6318 this->local_values();
6319 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6321 elfcpp::Sym<32, big_endian> sym(psyms);
6322 elfcpp::STT st_type = sym.get_st_type();
6323 Symbol_value<32>& lv((*plocal_values)[i]);
6324 Arm_address input_value = lv.input_value();
6326 // Check to see if this is a mapping symbol.
6327 const char* sym_name = pnames + sym.get_st_name();
6328 if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6330 bool is_ordinary;
6331 unsigned int input_shndx =
6332 this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6333 gold_assert(is_ordinary);
6335 // Strip of LSB in case this is a THUMB symbol.
6336 Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6337 this->mapping_symbols_info_[msp] = sym_name[1];
6340 if (st_type == elfcpp::STT_ARM_TFUNC
6341 || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6343 // This is a THUMB function. Mark this and canonicalize the
6344 // symbol value by setting LSB.
6345 this->local_symbol_is_thumb_function_[i] = true;
6346 if ((input_value & 1) == 0)
6347 lv.set_input_value(input_value | 1);
6352 // Relocate sections.
6353 template<bool big_endian>
6354 void
6355 Arm_relobj<big_endian>::do_relocate_sections(
6356 const Symbol_table* symtab,
6357 const Layout* layout,
6358 const unsigned char* pshdrs,
6359 Output_file* of,
6360 typename Sized_relobj<32, big_endian>::Views* pviews)
6362 // Call parent to relocate sections.
6363 Sized_relobj<32, big_endian>::do_relocate_sections(symtab, layout, pshdrs,
6364 of, pviews);
6366 // We do not generate stubs if doing a relocatable link.
6367 if (parameters->options().relocatable())
6368 return;
6370 // Relocate stub tables.
6371 unsigned int shnum = this->shnum();
6373 Target_arm<big_endian>* arm_target =
6374 Target_arm<big_endian>::default_target();
6376 Relocate_info<32, big_endian> relinfo;
6377 relinfo.symtab = symtab;
6378 relinfo.layout = layout;
6379 relinfo.object = this;
6381 for (unsigned int i = 1; i < shnum; ++i)
6383 Arm_input_section<big_endian>* arm_input_section =
6384 arm_target->find_arm_input_section(this, i);
6386 if (arm_input_section != NULL
6387 && arm_input_section->is_stub_table_owner()
6388 && !arm_input_section->stub_table()->empty())
6390 // We cannot discard a section if it owns a stub table.
6391 Output_section* os = this->output_section(i);
6392 gold_assert(os != NULL);
6394 relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6395 relinfo.reloc_shdr = NULL;
6396 relinfo.data_shndx = i;
6397 relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6399 gold_assert((*pviews)[i].view != NULL);
6401 // We are passed the output section view. Adjust it to cover the
6402 // stub table only.
6403 Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6404 gold_assert((stub_table->address() >= (*pviews)[i].address)
6405 && ((stub_table->address() + stub_table->data_size())
6406 <= (*pviews)[i].address + (*pviews)[i].view_size));
6408 off_t offset = stub_table->address() - (*pviews)[i].address;
6409 unsigned char* view = (*pviews)[i].view + offset;
6410 Arm_address address = stub_table->address();
6411 section_size_type view_size = stub_table->data_size();
6413 stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6414 view_size);
6417 // Apply Cortex A8 workaround if applicable.
6418 if (this->section_has_cortex_a8_workaround(i))
6420 unsigned char* view = (*pviews)[i].view;
6421 Arm_address view_address = (*pviews)[i].address;
6422 section_size_type view_size = (*pviews)[i].view_size;
6423 Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6425 // Adjust view to cover section.
6426 Output_section* os = this->output_section(i);
6427 gold_assert(os != NULL);
6428 Arm_address section_address =
6429 this->simple_input_section_output_address(i, os);
6430 uint64_t section_size = this->section_size(i);
6432 gold_assert(section_address >= view_address
6433 && ((section_address + section_size)
6434 <= (view_address + view_size)));
6436 unsigned char* section_view = view + (section_address - view_address);
6438 // Apply the Cortex-A8 workaround to the output address range
6439 // corresponding to this input section.
6440 stub_table->apply_cortex_a8_workaround_to_address_range(
6441 arm_target,
6442 section_view,
6443 section_address,
6444 section_size);
6449 // Find the linked text section of an EXIDX section by looking the the first
6450 // relocation. 4.4.1 of the EHABI specifications says that an EXIDX section
6451 // must be linked to to its associated code section via the sh_link field of
6452 // its section header. However, some tools are broken and the link is not
6453 // always set. LD just drops such an EXIDX section silently, causing the
6454 // associated code not unwindabled. Here we try a little bit harder to
6455 // discover the linked code section.
6457 // PSHDR points to the section header of a relocation section of an EXIDX
6458 // section. If we can find a linked text section, return true and
6459 // store the text section index in the location PSHNDX. Otherwise
6460 // return false.
6462 template<bool big_endian>
6463 bool
6464 Arm_relobj<big_endian>::find_linked_text_section(
6465 const unsigned char* pshdr,
6466 const unsigned char* psyms,
6467 unsigned int* pshndx)
6469 elfcpp::Shdr<32, big_endian> shdr(pshdr);
6471 // If there is no relocation, we cannot find the linked text section.
6472 size_t reloc_size;
6473 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6474 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6475 else
6476 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6477 size_t reloc_count = shdr.get_sh_size() / reloc_size;
6479 // Get the relocations.
6480 const unsigned char* prelocs =
6481 this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6483 // Find the REL31 relocation for the first word of the first EXIDX entry.
6484 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6486 Arm_address r_offset;
6487 typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6488 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6490 typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6491 r_info = reloc.get_r_info();
6492 r_offset = reloc.get_r_offset();
6494 else
6496 typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6497 r_info = reloc.get_r_info();
6498 r_offset = reloc.get_r_offset();
6501 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6502 if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6503 continue;
6505 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6506 if (r_sym == 0
6507 || r_sym >= this->local_symbol_count()
6508 || r_offset != 0)
6509 continue;
6511 // This is the relocation for the first word of the first EXIDX entry.
6512 // We expect to see a local section symbol.
6513 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6514 elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6515 if (sym.get_st_type() == elfcpp::STT_SECTION)
6517 bool is_ordinary;
6518 *pshndx =
6519 this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6520 gold_assert(is_ordinary);
6521 return true;
6523 else
6524 return false;
6527 return false;
6530 // Make an EXIDX input section object for an EXIDX section whose index is
6531 // SHNDX. SHDR is the section header of the EXIDX section and TEXT_SHNDX
6532 // is the section index of the linked text section.
6534 template<bool big_endian>
6535 void
6536 Arm_relobj<big_endian>::make_exidx_input_section(
6537 unsigned int shndx,
6538 const elfcpp::Shdr<32, big_endian>& shdr,
6539 unsigned int text_shndx,
6540 const elfcpp::Shdr<32, big_endian>& text_shdr)
6542 // Create an Arm_exidx_input_section object for this EXIDX section.
6543 Arm_exidx_input_section* exidx_input_section =
6544 new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6545 shdr.get_sh_addralign());
6547 gold_assert(this->exidx_section_map_[shndx] == NULL);
6548 this->exidx_section_map_[shndx] = exidx_input_section;
6550 if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6552 gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6553 this->section_name(shndx).c_str(), shndx, text_shndx,
6554 this->name().c_str());
6555 exidx_input_section->set_has_errors();
6557 else if (this->exidx_section_map_[text_shndx] != NULL)
6559 unsigned other_exidx_shndx =
6560 this->exidx_section_map_[text_shndx]->shndx();
6561 gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6562 "%s(%u) in %s"),
6563 this->section_name(shndx).c_str(), shndx,
6564 this->section_name(other_exidx_shndx).c_str(),
6565 other_exidx_shndx, this->section_name(text_shndx).c_str(),
6566 text_shndx, this->name().c_str());
6567 exidx_input_section->set_has_errors();
6569 else
6570 this->exidx_section_map_[text_shndx] = exidx_input_section;
6572 // Check section flags of text section.
6573 if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6575 gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6576 " in %s"),
6577 this->section_name(shndx).c_str(), shndx,
6578 this->section_name(text_shndx).c_str(), text_shndx,
6579 this->name().c_str());
6580 exidx_input_section->set_has_errors();
6582 else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6583 // I would like to make this an error but currenlty ld just ignores
6584 // this.
6585 gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6586 "%s(%u) in %s"),
6587 this->section_name(shndx).c_str(), shndx,
6588 this->section_name(text_shndx).c_str(), text_shndx,
6589 this->name().c_str());
6592 // Read the symbol information.
6594 template<bool big_endian>
6595 void
6596 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6598 // Call parent class to read symbol information.
6599 Sized_relobj<32, big_endian>::do_read_symbols(sd);
6601 // If this input file is a binary file, it has no processor
6602 // specific flags and attributes section.
6603 Input_file::Format format = this->input_file()->format();
6604 if (format != Input_file::FORMAT_ELF)
6606 gold_assert(format == Input_file::FORMAT_BINARY);
6607 this->merge_flags_and_attributes_ = false;
6608 return;
6611 // Read processor-specific flags in ELF file header.
6612 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6613 elfcpp::Elf_sizes<32>::ehdr_size,
6614 true, false);
6615 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6616 this->processor_specific_flags_ = ehdr.get_e_flags();
6618 // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6619 // sections.
6620 std::vector<unsigned int> deferred_exidx_sections;
6621 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6622 const unsigned char* pshdrs = sd->section_headers->data();
6623 const unsigned char* ps = pshdrs + shdr_size;
6624 bool must_merge_flags_and_attributes = false;
6625 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6627 elfcpp::Shdr<32, big_endian> shdr(ps);
6629 // Sometimes an object has no contents except the section name string
6630 // table and an empty symbol table with the undefined symbol. We
6631 // don't want to merge processor-specific flags from such an object.
6632 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6634 // Symbol table is not empty.
6635 const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6636 elfcpp::Elf_sizes<32>::sym_size;
6637 if (shdr.get_sh_size() > sym_size)
6638 must_merge_flags_and_attributes = true;
6640 else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6641 // If this is neither an empty symbol table nor a string table,
6642 // be conservative.
6643 must_merge_flags_and_attributes = true;
6645 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6647 gold_assert(this->attributes_section_data_ == NULL);
6648 section_offset_type section_offset = shdr.get_sh_offset();
6649 section_size_type section_size =
6650 convert_to_section_size_type(shdr.get_sh_size());
6651 File_view* view = this->get_lasting_view(section_offset,
6652 section_size, true, false);
6653 this->attributes_section_data_ =
6654 new Attributes_section_data(view->data(), section_size);
6656 else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6658 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6659 if (text_shndx == elfcpp::SHN_UNDEF)
6660 deferred_exidx_sections.push_back(i);
6661 else
6663 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6664 + text_shndx * shdr_size);
6665 this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6670 // This is rare.
6671 if (!must_merge_flags_and_attributes)
6673 gold_assert(deferred_exidx_sections.empty());
6674 this->merge_flags_and_attributes_ = false;
6675 return;
6678 // Some tools are broken and they do not set the link of EXIDX sections.
6679 // We look at the first relocation to figure out the linked sections.
6680 if (!deferred_exidx_sections.empty())
6682 // We need to go over the section headers again to find the mapping
6683 // from sections being relocated to their relocation sections. This is
6684 // a bit inefficient as we could do that in the loop above. However,
6685 // we do not expect any deferred EXIDX sections normally. So we do not
6686 // want to slow down the most common path.
6687 typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6688 Reloc_map reloc_map;
6689 ps = pshdrs + shdr_size;
6690 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6692 elfcpp::Shdr<32, big_endian> shdr(ps);
6693 elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6694 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6696 unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6697 if (info_shndx >= this->shnum())
6698 gold_error(_("relocation section %u has invalid info %u"),
6699 i, info_shndx);
6700 Reloc_map::value_type value(info_shndx, i);
6701 std::pair<Reloc_map::iterator, bool> result =
6702 reloc_map.insert(value);
6703 if (!result.second)
6704 gold_error(_("section %u has multiple relocation sections "
6705 "%u and %u"),
6706 info_shndx, i, reloc_map[info_shndx]);
6710 // Read the symbol table section header.
6711 const unsigned int symtab_shndx = this->symtab_shndx();
6712 elfcpp::Shdr<32, big_endian>
6713 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6714 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6716 // Read the local symbols.
6717 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6718 const unsigned int loccount = this->local_symbol_count();
6719 gold_assert(loccount == symtabshdr.get_sh_info());
6720 off_t locsize = loccount * sym_size;
6721 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6722 locsize, true, true);
6724 // Process the deferred EXIDX sections.
6725 for(unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6727 unsigned int shndx = deferred_exidx_sections[i];
6728 elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6729 unsigned int text_shndx = elfcpp::SHN_UNDEF;
6730 Reloc_map::const_iterator it = reloc_map.find(shndx);
6731 if (it != reloc_map.end())
6732 find_linked_text_section(pshdrs + it->second * shdr_size,
6733 psyms, &text_shndx);
6734 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6735 + text_shndx * shdr_size);
6736 this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6741 // Process relocations for garbage collection. The ARM target uses .ARM.exidx
6742 // sections for unwinding. These sections are referenced implicitly by
6743 // text sections linked in the section headers. If we ignore these implict
6744 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6745 // will be garbage-collected incorrectly. Hence we override the same function
6746 // in the base class to handle these implicit references.
6748 template<bool big_endian>
6749 void
6750 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6751 Layout* layout,
6752 Read_relocs_data* rd)
6754 // First, call base class method to process relocations in this object.
6755 Sized_relobj<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6757 // If --gc-sections is not specified, there is nothing more to do.
6758 // This happens when --icf is used but --gc-sections is not.
6759 if (!parameters->options().gc_sections())
6760 return;
6762 unsigned int shnum = this->shnum();
6763 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6764 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6765 shnum * shdr_size,
6766 true, true);
6768 // Scan section headers for sections of type SHT_ARM_EXIDX. Add references
6769 // to these from the linked text sections.
6770 const unsigned char* ps = pshdrs + shdr_size;
6771 for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6773 elfcpp::Shdr<32, big_endian> shdr(ps);
6774 if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6776 // Found an .ARM.exidx section, add it to the set of reachable
6777 // sections from its linked text section.
6778 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6779 symtab->gc()->add_reference(this, text_shndx, this, i);
6784 // Update output local symbol count. Owing to EXIDX entry merging, some local
6785 // symbols will be removed in output. Adjust output local symbol count
6786 // accordingly. We can only changed the static output local symbol count. It
6787 // is too late to change the dynamic symbols.
6789 template<bool big_endian>
6790 void
6791 Arm_relobj<big_endian>::update_output_local_symbol_count()
6793 // Caller should check that this needs updating. We want caller checking
6794 // because output_local_symbol_count_needs_update() is most likely inlined.
6795 gold_assert(this->output_local_symbol_count_needs_update_);
6797 gold_assert(this->symtab_shndx() != -1U);
6798 if (this->symtab_shndx() == 0)
6800 // This object has no symbols. Weird but legal.
6801 return;
6804 // Read the symbol table section header.
6805 const unsigned int symtab_shndx = this->symtab_shndx();
6806 elfcpp::Shdr<32, big_endian>
6807 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6808 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6810 // Read the local symbols.
6811 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6812 const unsigned int loccount = this->local_symbol_count();
6813 gold_assert(loccount == symtabshdr.get_sh_info());
6814 off_t locsize = loccount * sym_size;
6815 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6816 locsize, true, true);
6818 // Loop over the local symbols.
6820 typedef typename Sized_relobj<32, big_endian>::Output_sections
6821 Output_sections;
6822 const Output_sections& out_sections(this->output_sections());
6823 unsigned int shnum = this->shnum();
6824 unsigned int count = 0;
6825 // Skip the first, dummy, symbol.
6826 psyms += sym_size;
6827 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6829 elfcpp::Sym<32, big_endian> sym(psyms);
6831 Symbol_value<32>& lv((*this->local_values())[i]);
6833 // This local symbol was already discarded by do_count_local_symbols.
6834 if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6835 continue;
6837 bool is_ordinary;
6838 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6839 &is_ordinary);
6841 if (shndx < shnum)
6843 Output_section* os = out_sections[shndx];
6845 // This local symbol no longer has an output section. Discard it.
6846 if (os == NULL)
6848 lv.set_no_output_symtab_entry();
6849 continue;
6852 // Currently we only discard parts of EXIDX input sections.
6853 // We explicitly check for a merged EXIDX input section to avoid
6854 // calling Output_section_data::output_offset unless necessary.
6855 if ((this->get_output_section_offset(shndx) == invalid_address)
6856 && (this->exidx_input_section_by_shndx(shndx) != NULL))
6858 section_offset_type output_offset =
6859 os->output_offset(this, shndx, lv.input_value());
6860 if (output_offset == -1)
6862 // This symbol is defined in a part of an EXIDX input section
6863 // that is discarded due to entry merging.
6864 lv.set_no_output_symtab_entry();
6865 continue;
6870 ++count;
6873 this->set_output_local_symbol_count(count);
6874 this->output_local_symbol_count_needs_update_ = false;
6877 // Arm_dynobj methods.
6879 // Read the symbol information.
6881 template<bool big_endian>
6882 void
6883 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6885 // Call parent class to read symbol information.
6886 Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6888 // Read processor-specific flags in ELF file header.
6889 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6890 elfcpp::Elf_sizes<32>::ehdr_size,
6891 true, false);
6892 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6893 this->processor_specific_flags_ = ehdr.get_e_flags();
6895 // Read the attributes section if there is one.
6896 // We read from the end because gas seems to put it near the end of
6897 // the section headers.
6898 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6899 const unsigned char* ps =
6900 sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6901 for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6903 elfcpp::Shdr<32, big_endian> shdr(ps);
6904 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6906 section_offset_type section_offset = shdr.get_sh_offset();
6907 section_size_type section_size =
6908 convert_to_section_size_type(shdr.get_sh_size());
6909 File_view* view = this->get_lasting_view(section_offset,
6910 section_size, true, false);
6911 this->attributes_section_data_ =
6912 new Attributes_section_data(view->data(), section_size);
6913 break;
6918 // Stub_addend_reader methods.
6920 // Read the addend of a REL relocation of type R_TYPE at VIEW.
6922 template<bool big_endian>
6923 elfcpp::Elf_types<32>::Elf_Swxword
6924 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
6925 unsigned int r_type,
6926 const unsigned char* view,
6927 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
6929 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
6931 switch (r_type)
6933 case elfcpp::R_ARM_CALL:
6934 case elfcpp::R_ARM_JUMP24:
6935 case elfcpp::R_ARM_PLT32:
6937 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
6938 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6939 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
6940 return utils::sign_extend<26>(val << 2);
6943 case elfcpp::R_ARM_THM_CALL:
6944 case elfcpp::R_ARM_THM_JUMP24:
6945 case elfcpp::R_ARM_THM_XPC22:
6947 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
6948 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6949 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
6950 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
6951 return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
6954 case elfcpp::R_ARM_THM_JUMP19:
6956 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
6957 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6958 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
6959 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
6960 return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
6963 default:
6964 gold_unreachable();
6968 // Arm_output_data_got methods.
6970 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
6971 // The first one is initialized to be 1, which is the module index for
6972 // the main executable and the second one 0. A reloc of the type
6973 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
6974 // be applied by gold. GSYM is a global symbol.
6976 template<bool big_endian>
6977 void
6978 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
6979 unsigned int got_type,
6980 Symbol* gsym)
6982 if (gsym->has_got_offset(got_type))
6983 return;
6985 // We are doing a static link. Just mark it as belong to module 1,
6986 // the executable.
6987 unsigned int got_offset = this->add_constant(1);
6988 gsym->set_got_offset(got_type, got_offset);
6989 got_offset = this->add_constant(0);
6990 this->static_relocs_.push_back(Static_reloc(got_offset,
6991 elfcpp::R_ARM_TLS_DTPOFF32,
6992 gsym));
6995 // Same as the above but for a local symbol.
6997 template<bool big_endian>
6998 void
6999 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7000 unsigned int got_type,
7001 Sized_relobj<32, big_endian>* object,
7002 unsigned int index)
7004 if (object->local_has_got_offset(index, got_type))
7005 return;
7007 // We are doing a static link. Just mark it as belong to module 1,
7008 // the executable.
7009 unsigned int got_offset = this->add_constant(1);
7010 object->set_local_got_offset(index, got_type, got_offset);
7011 got_offset = this->add_constant(0);
7012 this->static_relocs_.push_back(Static_reloc(got_offset,
7013 elfcpp::R_ARM_TLS_DTPOFF32,
7014 object, index));
7017 template<bool big_endian>
7018 void
7019 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7021 // Call parent to write out GOT.
7022 Output_data_got<32, big_endian>::do_write(of);
7024 // We are done if there is no fix up.
7025 if (this->static_relocs_.empty())
7026 return;
7028 gold_assert(parameters->doing_static_link());
7030 const off_t offset = this->offset();
7031 const section_size_type oview_size =
7032 convert_to_section_size_type(this->data_size());
7033 unsigned char* const oview = of->get_output_view(offset, oview_size);
7035 Output_segment* tls_segment = this->layout_->tls_segment();
7036 gold_assert(tls_segment != NULL);
7038 // The thread pointer $tp points to the TCB, which is followed by the
7039 // TLS. So we need to adjust $tp relative addressing by this amount.
7040 Arm_address aligned_tcb_size =
7041 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7043 for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7045 Static_reloc& reloc(this->static_relocs_[i]);
7047 Arm_address value;
7048 if (!reloc.symbol_is_global())
7050 Sized_relobj<32, big_endian>* object = reloc.relobj();
7051 const Symbol_value<32>* psymval =
7052 reloc.relobj()->local_symbol(reloc.index());
7054 // We are doing static linking. Issue an error and skip this
7055 // relocation if the symbol is undefined or in a discarded_section.
7056 bool is_ordinary;
7057 unsigned int shndx = psymval->input_shndx(&is_ordinary);
7058 if ((shndx == elfcpp::SHN_UNDEF)
7059 || (is_ordinary
7060 && shndx != elfcpp::SHN_UNDEF
7061 && !object->is_section_included(shndx)
7062 && !this->symbol_table_->is_section_folded(object, shndx)))
7064 gold_error(_("undefined or discarded local symbol %u from "
7065 " object %s in GOT"),
7066 reloc.index(), reloc.relobj()->name().c_str());
7067 continue;
7070 value = psymval->value(object, 0);
7072 else
7074 const Symbol* gsym = reloc.symbol();
7075 gold_assert(gsym != NULL);
7076 if (gsym->is_forwarder())
7077 gsym = this->symbol_table_->resolve_forwards(gsym);
7079 // We are doing static linking. Issue an error and skip this
7080 // relocation if the symbol is undefined or in a discarded_section
7081 // unless it is a weakly_undefined symbol.
7082 if ((gsym->is_defined_in_discarded_section()
7083 || gsym->is_undefined())
7084 && !gsym->is_weak_undefined())
7086 gold_error(_("undefined or discarded symbol %s in GOT"),
7087 gsym->name());
7088 continue;
7091 if (!gsym->is_weak_undefined())
7093 const Sized_symbol<32>* sym =
7094 static_cast<const Sized_symbol<32>*>(gsym);
7095 value = sym->value();
7097 else
7098 value = 0;
7101 unsigned got_offset = reloc.got_offset();
7102 gold_assert(got_offset < oview_size);
7104 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7105 Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7106 Valtype x;
7107 switch (reloc.r_type())
7109 case elfcpp::R_ARM_TLS_DTPOFF32:
7110 x = value;
7111 break;
7112 case elfcpp::R_ARM_TLS_TPOFF32:
7113 x = value + aligned_tcb_size;
7114 break;
7115 default:
7116 gold_unreachable();
7118 elfcpp::Swap<32, big_endian>::writeval(wv, x);
7121 of->write_output_view(offset, oview_size, oview);
7124 // A class to handle the PLT data.
7126 template<bool big_endian>
7127 class Output_data_plt_arm : public Output_section_data
7129 public:
7130 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7131 Reloc_section;
7133 Output_data_plt_arm(Layout*, Output_data_space*);
7135 // Add an entry to the PLT.
7136 void
7137 add_entry(Symbol* gsym);
7139 // Return the .rel.plt section data.
7140 const Reloc_section*
7141 rel_plt() const
7142 { return this->rel_; }
7144 // Return the number of PLT entries.
7145 unsigned int
7146 entry_count() const
7147 { return this->count_; }
7149 // Return the offset of the first non-reserved PLT entry.
7150 static unsigned int
7151 first_plt_entry_offset()
7152 { return sizeof(first_plt_entry); }
7154 // Return the size of a PLT entry.
7155 static unsigned int
7156 get_plt_entry_size()
7157 { return sizeof(plt_entry); }
7159 protected:
7160 void
7161 do_adjust_output_section(Output_section* os);
7163 // Write to a map file.
7164 void
7165 do_print_to_mapfile(Mapfile* mapfile) const
7166 { mapfile->print_output_data(this, _("** PLT")); }
7168 private:
7169 // Template for the first PLT entry.
7170 static const uint32_t first_plt_entry[5];
7172 // Template for subsequent PLT entries.
7173 static const uint32_t plt_entry[3];
7175 // Set the final size.
7176 void
7177 set_final_data_size()
7179 this->set_data_size(sizeof(first_plt_entry)
7180 + this->count_ * sizeof(plt_entry));
7183 // Write out the PLT data.
7184 void
7185 do_write(Output_file*);
7187 // The reloc section.
7188 Reloc_section* rel_;
7189 // The .got.plt section.
7190 Output_data_space* got_plt_;
7191 // The number of PLT entries.
7192 unsigned int count_;
7195 // Create the PLT section. The ordinary .got section is an argument,
7196 // since we need to refer to the start. We also create our own .got
7197 // section just for PLT entries.
7199 template<bool big_endian>
7200 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7201 Output_data_space* got_plt)
7202 : Output_section_data(4), got_plt_(got_plt), count_(0)
7204 this->rel_ = new Reloc_section(false);
7205 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7206 elfcpp::SHF_ALLOC, this->rel_,
7207 ORDER_DYNAMIC_PLT_RELOCS, false);
7210 template<bool big_endian>
7211 void
7212 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7214 os->set_entsize(0);
7217 // Add an entry to the PLT.
7219 template<bool big_endian>
7220 void
7221 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7223 gold_assert(!gsym->has_plt_offset());
7225 // Note that when setting the PLT offset we skip the initial
7226 // reserved PLT entry.
7227 gsym->set_plt_offset((this->count_) * sizeof(plt_entry)
7228 + sizeof(first_plt_entry));
7230 ++this->count_;
7232 section_offset_type got_offset = this->got_plt_->current_data_size();
7234 // Every PLT entry needs a GOT entry which points back to the PLT
7235 // entry (this will be changed by the dynamic linker, normally
7236 // lazily when the function is called).
7237 this->got_plt_->set_current_data_size(got_offset + 4);
7239 // Every PLT entry needs a reloc.
7240 gsym->set_needs_dynsym_entry();
7241 this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7242 got_offset);
7244 // Note that we don't need to save the symbol. The contents of the
7245 // PLT are independent of which symbols are used. The symbols only
7246 // appear in the relocations.
7249 // ARM PLTs.
7250 // FIXME: This is not very flexible. Right now this has only been tested
7251 // on armv5te. If we are to support additional architecture features like
7252 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7254 // The first entry in the PLT.
7255 template<bool big_endian>
7256 const uint32_t Output_data_plt_arm<big_endian>::first_plt_entry[5] =
7258 0xe52de004, // str lr, [sp, #-4]!
7259 0xe59fe004, // ldr lr, [pc, #4]
7260 0xe08fe00e, // add lr, pc, lr
7261 0xe5bef008, // ldr pc, [lr, #8]!
7262 0x00000000, // &GOT[0] - .
7265 // Subsequent entries in the PLT.
7267 template<bool big_endian>
7268 const uint32_t Output_data_plt_arm<big_endian>::plt_entry[3] =
7270 0xe28fc600, // add ip, pc, #0xNN00000
7271 0xe28cca00, // add ip, ip, #0xNN000
7272 0xe5bcf000, // ldr pc, [ip, #0xNNN]!
7275 // Write out the PLT. This uses the hand-coded instructions above,
7276 // and adjusts them as needed. This is all specified by the arm ELF
7277 // Processor Supplement.
7279 template<bool big_endian>
7280 void
7281 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7283 const off_t offset = this->offset();
7284 const section_size_type oview_size =
7285 convert_to_section_size_type(this->data_size());
7286 unsigned char* const oview = of->get_output_view(offset, oview_size);
7288 const off_t got_file_offset = this->got_plt_->offset();
7289 const section_size_type got_size =
7290 convert_to_section_size_type(this->got_plt_->data_size());
7291 unsigned char* const got_view = of->get_output_view(got_file_offset,
7292 got_size);
7293 unsigned char* pov = oview;
7295 Arm_address plt_address = this->address();
7296 Arm_address got_address = this->got_plt_->address();
7298 // Write first PLT entry. All but the last word are constants.
7299 const size_t num_first_plt_words = (sizeof(first_plt_entry)
7300 / sizeof(plt_entry[0]));
7301 for (size_t i = 0; i < num_first_plt_words - 1; i++)
7302 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7303 // Last word in first PLT entry is &GOT[0] - .
7304 elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7305 got_address - (plt_address + 16));
7306 pov += sizeof(first_plt_entry);
7308 unsigned char* got_pov = got_view;
7310 memset(got_pov, 0, 12);
7311 got_pov += 12;
7313 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
7314 unsigned int plt_offset = sizeof(first_plt_entry);
7315 unsigned int plt_rel_offset = 0;
7316 unsigned int got_offset = 12;
7317 const unsigned int count = this->count_;
7318 for (unsigned int i = 0;
7319 i < count;
7320 ++i,
7321 pov += sizeof(plt_entry),
7322 got_pov += 4,
7323 plt_offset += sizeof(plt_entry),
7324 plt_rel_offset += rel_size,
7325 got_offset += 4)
7327 // Set and adjust the PLT entry itself.
7328 int32_t offset = ((got_address + got_offset)
7329 - (plt_address + plt_offset + 8));
7331 gold_assert(offset >= 0 && offset < 0x0fffffff);
7332 uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7333 elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7334 uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7335 elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7336 uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7337 elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7339 // Set the entry in the GOT.
7340 elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7343 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7344 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7346 of->write_output_view(offset, oview_size, oview);
7347 of->write_output_view(got_file_offset, got_size, got_view);
7350 // Create a PLT entry for a global symbol.
7352 template<bool big_endian>
7353 void
7354 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7355 Symbol* gsym)
7357 if (gsym->has_plt_offset())
7358 return;
7360 if (this->plt_ == NULL)
7362 // Create the GOT sections first.
7363 this->got_section(symtab, layout);
7365 this->plt_ = new Output_data_plt_arm<big_endian>(layout, this->got_plt_);
7366 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7367 (elfcpp::SHF_ALLOC
7368 | elfcpp::SHF_EXECINSTR),
7369 this->plt_, ORDER_PLT, false);
7371 this->plt_->add_entry(gsym);
7374 // Return the number of entries in the PLT.
7376 template<bool big_endian>
7377 unsigned int
7378 Target_arm<big_endian>::plt_entry_count() const
7380 if (this->plt_ == NULL)
7381 return 0;
7382 return this->plt_->entry_count();
7385 // Return the offset of the first non-reserved PLT entry.
7387 template<bool big_endian>
7388 unsigned int
7389 Target_arm<big_endian>::first_plt_entry_offset() const
7391 return Output_data_plt_arm<big_endian>::first_plt_entry_offset();
7394 // Return the size of each PLT entry.
7396 template<bool big_endian>
7397 unsigned int
7398 Target_arm<big_endian>::plt_entry_size() const
7400 return Output_data_plt_arm<big_endian>::get_plt_entry_size();
7403 // Get the section to use for TLS_DESC relocations.
7405 template<bool big_endian>
7406 typename Target_arm<big_endian>::Reloc_section*
7407 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7409 return this->plt_section()->rel_tls_desc(layout);
7412 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7414 template<bool big_endian>
7415 void
7416 Target_arm<big_endian>::define_tls_base_symbol(
7417 Symbol_table* symtab,
7418 Layout* layout)
7420 if (this->tls_base_symbol_defined_)
7421 return;
7423 Output_segment* tls_segment = layout->tls_segment();
7424 if (tls_segment != NULL)
7426 bool is_exec = parameters->options().output_is_executable();
7427 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7428 Symbol_table::PREDEFINED,
7429 tls_segment, 0, 0,
7430 elfcpp::STT_TLS,
7431 elfcpp::STB_LOCAL,
7432 elfcpp::STV_HIDDEN, 0,
7433 (is_exec
7434 ? Symbol::SEGMENT_END
7435 : Symbol::SEGMENT_START),
7436 true);
7438 this->tls_base_symbol_defined_ = true;
7441 // Create a GOT entry for the TLS module index.
7443 template<bool big_endian>
7444 unsigned int
7445 Target_arm<big_endian>::got_mod_index_entry(
7446 Symbol_table* symtab,
7447 Layout* layout,
7448 Sized_relobj<32, big_endian>* object)
7450 if (this->got_mod_index_offset_ == -1U)
7452 gold_assert(symtab != NULL && layout != NULL && object != NULL);
7453 Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7454 unsigned int got_offset;
7455 if (!parameters->doing_static_link())
7457 got_offset = got->add_constant(0);
7458 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7459 rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7460 got_offset);
7462 else
7464 // We are doing a static link. Just mark it as belong to module 1,
7465 // the executable.
7466 got_offset = got->add_constant(1);
7469 got->add_constant(0);
7470 this->got_mod_index_offset_ = got_offset;
7472 return this->got_mod_index_offset_;
7475 // Optimize the TLS relocation type based on what we know about the
7476 // symbol. IS_FINAL is true if the final address of this symbol is
7477 // known at link time.
7479 template<bool big_endian>
7480 tls::Tls_optimization
7481 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7483 // FIXME: Currently we do not do any TLS optimization.
7484 return tls::TLSOPT_NONE;
7487 // Report an unsupported relocation against a local symbol.
7489 template<bool big_endian>
7490 void
7491 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7492 Sized_relobj<32, big_endian>* object,
7493 unsigned int r_type)
7495 gold_error(_("%s: unsupported reloc %u against local symbol"),
7496 object->name().c_str(), r_type);
7499 // We are about to emit a dynamic relocation of type R_TYPE. If the
7500 // dynamic linker does not support it, issue an error. The GNU linker
7501 // only issues a non-PIC error for an allocated read-only section.
7502 // Here we know the section is allocated, but we don't know that it is
7503 // read-only. But we check for all the relocation types which the
7504 // glibc dynamic linker supports, so it seems appropriate to issue an
7505 // error even if the section is not read-only.
7507 template<bool big_endian>
7508 void
7509 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7510 unsigned int r_type)
7512 switch (r_type)
7514 // These are the relocation types supported by glibc for ARM.
7515 case elfcpp::R_ARM_RELATIVE:
7516 case elfcpp::R_ARM_COPY:
7517 case elfcpp::R_ARM_GLOB_DAT:
7518 case elfcpp::R_ARM_JUMP_SLOT:
7519 case elfcpp::R_ARM_ABS32:
7520 case elfcpp::R_ARM_ABS32_NOI:
7521 case elfcpp::R_ARM_PC24:
7522 // FIXME: The following 3 types are not supported by Android's dynamic
7523 // linker.
7524 case elfcpp::R_ARM_TLS_DTPMOD32:
7525 case elfcpp::R_ARM_TLS_DTPOFF32:
7526 case elfcpp::R_ARM_TLS_TPOFF32:
7527 return;
7529 default:
7531 // This prevents us from issuing more than one error per reloc
7532 // section. But we can still wind up issuing more than one
7533 // error per object file.
7534 if (this->issued_non_pic_error_)
7535 return;
7536 const Arm_reloc_property* reloc_property =
7537 arm_reloc_property_table->get_reloc_property(r_type);
7538 gold_assert(reloc_property != NULL);
7539 object->error(_("requires unsupported dynamic reloc %s; "
7540 "recompile with -fPIC"),
7541 reloc_property->name().c_str());
7542 this->issued_non_pic_error_ = true;
7543 return;
7546 case elfcpp::R_ARM_NONE:
7547 gold_unreachable();
7551 // Scan a relocation for a local symbol.
7552 // FIXME: This only handles a subset of relocation types used by Android
7553 // on ARM v5te devices.
7555 template<bool big_endian>
7556 inline void
7557 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7558 Layout* layout,
7559 Target_arm* target,
7560 Sized_relobj<32, big_endian>* object,
7561 unsigned int data_shndx,
7562 Output_section* output_section,
7563 const elfcpp::Rel<32, big_endian>& reloc,
7564 unsigned int r_type,
7565 const elfcpp::Sym<32, big_endian>& lsym)
7567 r_type = get_real_reloc_type(r_type);
7568 switch (r_type)
7570 case elfcpp::R_ARM_NONE:
7571 case elfcpp::R_ARM_V4BX:
7572 case elfcpp::R_ARM_GNU_VTENTRY:
7573 case elfcpp::R_ARM_GNU_VTINHERIT:
7574 break;
7576 case elfcpp::R_ARM_ABS32:
7577 case elfcpp::R_ARM_ABS32_NOI:
7578 // If building a shared library (or a position-independent
7579 // executable), we need to create a dynamic relocation for
7580 // this location. The relocation applied at link time will
7581 // apply the link-time value, so we flag the location with
7582 // an R_ARM_RELATIVE relocation so the dynamic loader can
7583 // relocate it easily.
7584 if (parameters->options().output_is_position_independent())
7586 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7587 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7588 // If we are to add more other reloc types than R_ARM_ABS32,
7589 // we need to add check_non_pic(object, r_type) here.
7590 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7591 output_section, data_shndx,
7592 reloc.get_r_offset());
7594 break;
7596 case elfcpp::R_ARM_ABS16:
7597 case elfcpp::R_ARM_ABS12:
7598 case elfcpp::R_ARM_THM_ABS5:
7599 case elfcpp::R_ARM_ABS8:
7600 case elfcpp::R_ARM_BASE_ABS:
7601 case elfcpp::R_ARM_MOVW_ABS_NC:
7602 case elfcpp::R_ARM_MOVT_ABS:
7603 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7604 case elfcpp::R_ARM_THM_MOVT_ABS:
7605 // If building a shared library (or a position-independent
7606 // executable), we need to create a dynamic relocation for
7607 // this location. Because the addend needs to remain in the
7608 // data section, we need to be careful not to apply this
7609 // relocation statically.
7610 if (parameters->options().output_is_position_independent())
7612 check_non_pic(object, r_type);
7613 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7614 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7615 if (lsym.get_st_type() != elfcpp::STT_SECTION)
7616 rel_dyn->add_local(object, r_sym, r_type, output_section,
7617 data_shndx, reloc.get_r_offset());
7618 else
7620 gold_assert(lsym.get_st_value() == 0);
7621 unsigned int shndx = lsym.get_st_shndx();
7622 bool is_ordinary;
7623 shndx = object->adjust_sym_shndx(r_sym, shndx,
7624 &is_ordinary);
7625 if (!is_ordinary)
7626 object->error(_("section symbol %u has bad shndx %u"),
7627 r_sym, shndx);
7628 else
7629 rel_dyn->add_local_section(object, shndx,
7630 r_type, output_section,
7631 data_shndx, reloc.get_r_offset());
7634 break;
7636 case elfcpp::R_ARM_PC24:
7637 case elfcpp::R_ARM_REL32:
7638 case elfcpp::R_ARM_LDR_PC_G0:
7639 case elfcpp::R_ARM_SBREL32:
7640 case elfcpp::R_ARM_THM_CALL:
7641 case elfcpp::R_ARM_THM_PC8:
7642 case elfcpp::R_ARM_BASE_PREL:
7643 case elfcpp::R_ARM_PLT32:
7644 case elfcpp::R_ARM_CALL:
7645 case elfcpp::R_ARM_JUMP24:
7646 case elfcpp::R_ARM_THM_JUMP24:
7647 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7648 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7649 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7650 case elfcpp::R_ARM_SBREL31:
7651 case elfcpp::R_ARM_PREL31:
7652 case elfcpp::R_ARM_MOVW_PREL_NC:
7653 case elfcpp::R_ARM_MOVT_PREL:
7654 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7655 case elfcpp::R_ARM_THM_MOVT_PREL:
7656 case elfcpp::R_ARM_THM_JUMP19:
7657 case elfcpp::R_ARM_THM_JUMP6:
7658 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7659 case elfcpp::R_ARM_THM_PC12:
7660 case elfcpp::R_ARM_REL32_NOI:
7661 case elfcpp::R_ARM_ALU_PC_G0_NC:
7662 case elfcpp::R_ARM_ALU_PC_G0:
7663 case elfcpp::R_ARM_ALU_PC_G1_NC:
7664 case elfcpp::R_ARM_ALU_PC_G1:
7665 case elfcpp::R_ARM_ALU_PC_G2:
7666 case elfcpp::R_ARM_LDR_PC_G1:
7667 case elfcpp::R_ARM_LDR_PC_G2:
7668 case elfcpp::R_ARM_LDRS_PC_G0:
7669 case elfcpp::R_ARM_LDRS_PC_G1:
7670 case elfcpp::R_ARM_LDRS_PC_G2:
7671 case elfcpp::R_ARM_LDC_PC_G0:
7672 case elfcpp::R_ARM_LDC_PC_G1:
7673 case elfcpp::R_ARM_LDC_PC_G2:
7674 case elfcpp::R_ARM_ALU_SB_G0_NC:
7675 case elfcpp::R_ARM_ALU_SB_G0:
7676 case elfcpp::R_ARM_ALU_SB_G1_NC:
7677 case elfcpp::R_ARM_ALU_SB_G1:
7678 case elfcpp::R_ARM_ALU_SB_G2:
7679 case elfcpp::R_ARM_LDR_SB_G0:
7680 case elfcpp::R_ARM_LDR_SB_G1:
7681 case elfcpp::R_ARM_LDR_SB_G2:
7682 case elfcpp::R_ARM_LDRS_SB_G0:
7683 case elfcpp::R_ARM_LDRS_SB_G1:
7684 case elfcpp::R_ARM_LDRS_SB_G2:
7685 case elfcpp::R_ARM_LDC_SB_G0:
7686 case elfcpp::R_ARM_LDC_SB_G1:
7687 case elfcpp::R_ARM_LDC_SB_G2:
7688 case elfcpp::R_ARM_MOVW_BREL_NC:
7689 case elfcpp::R_ARM_MOVT_BREL:
7690 case elfcpp::R_ARM_MOVW_BREL:
7691 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7692 case elfcpp::R_ARM_THM_MOVT_BREL:
7693 case elfcpp::R_ARM_THM_MOVW_BREL:
7694 case elfcpp::R_ARM_THM_JUMP11:
7695 case elfcpp::R_ARM_THM_JUMP8:
7696 // We don't need to do anything for a relative addressing relocation
7697 // against a local symbol if it does not reference the GOT.
7698 break;
7700 case elfcpp::R_ARM_GOTOFF32:
7701 case elfcpp::R_ARM_GOTOFF12:
7702 // We need a GOT section:
7703 target->got_section(symtab, layout);
7704 break;
7706 case elfcpp::R_ARM_GOT_BREL:
7707 case elfcpp::R_ARM_GOT_PREL:
7709 // The symbol requires a GOT entry.
7710 Arm_output_data_got<big_endian>* got =
7711 target->got_section(symtab, layout);
7712 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7713 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
7715 // If we are generating a shared object, we need to add a
7716 // dynamic RELATIVE relocation for this symbol's GOT entry.
7717 if (parameters->options().output_is_position_independent())
7719 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7720 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7721 rel_dyn->add_local_relative(
7722 object, r_sym, elfcpp::R_ARM_RELATIVE, got,
7723 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
7727 break;
7729 case elfcpp::R_ARM_TARGET1:
7730 case elfcpp::R_ARM_TARGET2:
7731 // This should have been mapped to another type already.
7732 // Fall through.
7733 case elfcpp::R_ARM_COPY:
7734 case elfcpp::R_ARM_GLOB_DAT:
7735 case elfcpp::R_ARM_JUMP_SLOT:
7736 case elfcpp::R_ARM_RELATIVE:
7737 // These are relocations which should only be seen by the
7738 // dynamic linker, and should never be seen here.
7739 gold_error(_("%s: unexpected reloc %u in object file"),
7740 object->name().c_str(), r_type);
7741 break;
7744 // These are initial TLS relocs, which are expected when
7745 // linking.
7746 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7747 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7748 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7749 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7750 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7752 bool output_is_shared = parameters->options().shared();
7753 const tls::Tls_optimization optimized_type
7754 = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
7755 r_type);
7756 switch (r_type)
7758 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7759 if (optimized_type == tls::TLSOPT_NONE)
7761 // Create a pair of GOT entries for the module index and
7762 // dtv-relative offset.
7763 Arm_output_data_got<big_endian>* got
7764 = target->got_section(symtab, layout);
7765 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7766 unsigned int shndx = lsym.get_st_shndx();
7767 bool is_ordinary;
7768 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
7769 if (!is_ordinary)
7771 object->error(_("local symbol %u has bad shndx %u"),
7772 r_sym, shndx);
7773 break;
7776 if (!parameters->doing_static_link())
7777 got->add_local_pair_with_rel(object, r_sym, shndx,
7778 GOT_TYPE_TLS_PAIR,
7779 target->rel_dyn_section(layout),
7780 elfcpp::R_ARM_TLS_DTPMOD32, 0);
7781 else
7782 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
7783 object, r_sym);
7785 else
7786 // FIXME: TLS optimization not supported yet.
7787 gold_unreachable();
7788 break;
7790 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7791 if (optimized_type == tls::TLSOPT_NONE)
7793 // Create a GOT entry for the module index.
7794 target->got_mod_index_entry(symtab, layout, object);
7796 else
7797 // FIXME: TLS optimization not supported yet.
7798 gold_unreachable();
7799 break;
7801 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7802 break;
7804 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7805 layout->set_has_static_tls();
7806 if (optimized_type == tls::TLSOPT_NONE)
7808 // Create a GOT entry for the tp-relative offset.
7809 Arm_output_data_got<big_endian>* got
7810 = target->got_section(symtab, layout);
7811 unsigned int r_sym =
7812 elfcpp::elf_r_sym<32>(reloc.get_r_info());
7813 if (!parameters->doing_static_link())
7814 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
7815 target->rel_dyn_section(layout),
7816 elfcpp::R_ARM_TLS_TPOFF32);
7817 else if (!object->local_has_got_offset(r_sym,
7818 GOT_TYPE_TLS_OFFSET))
7820 got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
7821 unsigned int got_offset =
7822 object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
7823 got->add_static_reloc(got_offset,
7824 elfcpp::R_ARM_TLS_TPOFF32, object,
7825 r_sym);
7828 else
7829 // FIXME: TLS optimization not supported yet.
7830 gold_unreachable();
7831 break;
7833 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7834 layout->set_has_static_tls();
7835 if (output_is_shared)
7837 // We need to create a dynamic relocation.
7838 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
7839 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7840 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7841 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
7842 output_section, data_shndx,
7843 reloc.get_r_offset());
7845 break;
7847 default:
7848 gold_unreachable();
7851 break;
7853 default:
7854 unsupported_reloc_local(object, r_type);
7855 break;
7859 // Report an unsupported relocation against a global symbol.
7861 template<bool big_endian>
7862 void
7863 Target_arm<big_endian>::Scan::unsupported_reloc_global(
7864 Sized_relobj<32, big_endian>* object,
7865 unsigned int r_type,
7866 Symbol* gsym)
7868 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
7869 object->name().c_str(), r_type, gsym->demangled_name().c_str());
7872 template<bool big_endian>
7873 inline bool
7874 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
7875 unsigned int r_type)
7877 switch (r_type)
7879 case elfcpp::R_ARM_PC24:
7880 case elfcpp::R_ARM_THM_CALL:
7881 case elfcpp::R_ARM_PLT32:
7882 case elfcpp::R_ARM_CALL:
7883 case elfcpp::R_ARM_JUMP24:
7884 case elfcpp::R_ARM_THM_JUMP24:
7885 case elfcpp::R_ARM_SBREL31:
7886 case elfcpp::R_ARM_PREL31:
7887 case elfcpp::R_ARM_THM_JUMP19:
7888 case elfcpp::R_ARM_THM_JUMP6:
7889 case elfcpp::R_ARM_THM_JUMP11:
7890 case elfcpp::R_ARM_THM_JUMP8:
7891 // All the relocations above are branches except SBREL31 and PREL31.
7892 return false;
7894 default:
7895 // Be conservative and assume this is a function pointer.
7896 return true;
7900 template<bool big_endian>
7901 inline bool
7902 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
7903 Symbol_table*,
7904 Layout*,
7905 Target_arm<big_endian>* target,
7906 Sized_relobj<32, big_endian>*,
7907 unsigned int,
7908 Output_section*,
7909 const elfcpp::Rel<32, big_endian>&,
7910 unsigned int r_type,
7911 const elfcpp::Sym<32, big_endian>&)
7913 r_type = target->get_real_reloc_type(r_type);
7914 return possible_function_pointer_reloc(r_type);
7917 template<bool big_endian>
7918 inline bool
7919 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
7920 Symbol_table*,
7921 Layout*,
7922 Target_arm<big_endian>* target,
7923 Sized_relobj<32, big_endian>*,
7924 unsigned int,
7925 Output_section*,
7926 const elfcpp::Rel<32, big_endian>&,
7927 unsigned int r_type,
7928 Symbol* gsym)
7930 // GOT is not a function.
7931 if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
7932 return false;
7934 r_type = target->get_real_reloc_type(r_type);
7935 return possible_function_pointer_reloc(r_type);
7938 // Scan a relocation for a global symbol.
7940 template<bool big_endian>
7941 inline void
7942 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
7943 Layout* layout,
7944 Target_arm* target,
7945 Sized_relobj<32, big_endian>* object,
7946 unsigned int data_shndx,
7947 Output_section* output_section,
7948 const elfcpp::Rel<32, big_endian>& reloc,
7949 unsigned int r_type,
7950 Symbol* gsym)
7952 // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
7953 // section. We check here to avoid creating a dynamic reloc against
7954 // _GLOBAL_OFFSET_TABLE_.
7955 if (!target->has_got_section()
7956 && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
7957 target->got_section(symtab, layout);
7959 r_type = get_real_reloc_type(r_type);
7960 switch (r_type)
7962 case elfcpp::R_ARM_NONE:
7963 case elfcpp::R_ARM_V4BX:
7964 case elfcpp::R_ARM_GNU_VTENTRY:
7965 case elfcpp::R_ARM_GNU_VTINHERIT:
7966 break;
7968 case elfcpp::R_ARM_ABS32:
7969 case elfcpp::R_ARM_ABS16:
7970 case elfcpp::R_ARM_ABS12:
7971 case elfcpp::R_ARM_THM_ABS5:
7972 case elfcpp::R_ARM_ABS8:
7973 case elfcpp::R_ARM_BASE_ABS:
7974 case elfcpp::R_ARM_MOVW_ABS_NC:
7975 case elfcpp::R_ARM_MOVT_ABS:
7976 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7977 case elfcpp::R_ARM_THM_MOVT_ABS:
7978 case elfcpp::R_ARM_ABS32_NOI:
7979 // Absolute addressing relocations.
7981 // Make a PLT entry if necessary.
7982 if (this->symbol_needs_plt_entry(gsym))
7984 target->make_plt_entry(symtab, layout, gsym);
7985 // Since this is not a PC-relative relocation, we may be
7986 // taking the address of a function. In that case we need to
7987 // set the entry in the dynamic symbol table to the address of
7988 // the PLT entry.
7989 if (gsym->is_from_dynobj() && !parameters->options().shared())
7990 gsym->set_needs_dynsym_value();
7992 // Make a dynamic relocation if necessary.
7993 if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
7995 if (gsym->may_need_copy_reloc())
7997 target->copy_reloc(symtab, layout, object,
7998 data_shndx, output_section, gsym, reloc);
8000 else if ((r_type == elfcpp::R_ARM_ABS32
8001 || r_type == elfcpp::R_ARM_ABS32_NOI)
8002 && gsym->can_use_relative_reloc(false))
8004 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8005 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8006 output_section, object,
8007 data_shndx, reloc.get_r_offset());
8009 else
8011 check_non_pic(object, r_type);
8012 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8013 rel_dyn->add_global(gsym, r_type, output_section, object,
8014 data_shndx, reloc.get_r_offset());
8018 break;
8020 case elfcpp::R_ARM_GOTOFF32:
8021 case elfcpp::R_ARM_GOTOFF12:
8022 // We need a GOT section.
8023 target->got_section(symtab, layout);
8024 break;
8026 case elfcpp::R_ARM_REL32:
8027 case elfcpp::R_ARM_LDR_PC_G0:
8028 case elfcpp::R_ARM_SBREL32:
8029 case elfcpp::R_ARM_THM_PC8:
8030 case elfcpp::R_ARM_BASE_PREL:
8031 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8032 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8033 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8034 case elfcpp::R_ARM_MOVW_PREL_NC:
8035 case elfcpp::R_ARM_MOVT_PREL:
8036 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8037 case elfcpp::R_ARM_THM_MOVT_PREL:
8038 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8039 case elfcpp::R_ARM_THM_PC12:
8040 case elfcpp::R_ARM_REL32_NOI:
8041 case elfcpp::R_ARM_ALU_PC_G0_NC:
8042 case elfcpp::R_ARM_ALU_PC_G0:
8043 case elfcpp::R_ARM_ALU_PC_G1_NC:
8044 case elfcpp::R_ARM_ALU_PC_G1:
8045 case elfcpp::R_ARM_ALU_PC_G2:
8046 case elfcpp::R_ARM_LDR_PC_G1:
8047 case elfcpp::R_ARM_LDR_PC_G2:
8048 case elfcpp::R_ARM_LDRS_PC_G0:
8049 case elfcpp::R_ARM_LDRS_PC_G1:
8050 case elfcpp::R_ARM_LDRS_PC_G2:
8051 case elfcpp::R_ARM_LDC_PC_G0:
8052 case elfcpp::R_ARM_LDC_PC_G1:
8053 case elfcpp::R_ARM_LDC_PC_G2:
8054 case elfcpp::R_ARM_ALU_SB_G0_NC:
8055 case elfcpp::R_ARM_ALU_SB_G0:
8056 case elfcpp::R_ARM_ALU_SB_G1_NC:
8057 case elfcpp::R_ARM_ALU_SB_G1:
8058 case elfcpp::R_ARM_ALU_SB_G2:
8059 case elfcpp::R_ARM_LDR_SB_G0:
8060 case elfcpp::R_ARM_LDR_SB_G1:
8061 case elfcpp::R_ARM_LDR_SB_G2:
8062 case elfcpp::R_ARM_LDRS_SB_G0:
8063 case elfcpp::R_ARM_LDRS_SB_G1:
8064 case elfcpp::R_ARM_LDRS_SB_G2:
8065 case elfcpp::R_ARM_LDC_SB_G0:
8066 case elfcpp::R_ARM_LDC_SB_G1:
8067 case elfcpp::R_ARM_LDC_SB_G2:
8068 case elfcpp::R_ARM_MOVW_BREL_NC:
8069 case elfcpp::R_ARM_MOVT_BREL:
8070 case elfcpp::R_ARM_MOVW_BREL:
8071 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8072 case elfcpp::R_ARM_THM_MOVT_BREL:
8073 case elfcpp::R_ARM_THM_MOVW_BREL:
8074 // Relative addressing relocations.
8076 // Make a dynamic relocation if necessary.
8077 int flags = Symbol::NON_PIC_REF;
8078 if (gsym->needs_dynamic_reloc(flags))
8080 if (target->may_need_copy_reloc(gsym))
8082 target->copy_reloc(symtab, layout, object,
8083 data_shndx, output_section, gsym, reloc);
8085 else
8087 check_non_pic(object, r_type);
8088 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8089 rel_dyn->add_global(gsym, r_type, output_section, object,
8090 data_shndx, reloc.get_r_offset());
8094 break;
8096 case elfcpp::R_ARM_PC24:
8097 case elfcpp::R_ARM_THM_CALL:
8098 case elfcpp::R_ARM_PLT32:
8099 case elfcpp::R_ARM_CALL:
8100 case elfcpp::R_ARM_JUMP24:
8101 case elfcpp::R_ARM_THM_JUMP24:
8102 case elfcpp::R_ARM_SBREL31:
8103 case elfcpp::R_ARM_PREL31:
8104 case elfcpp::R_ARM_THM_JUMP19:
8105 case elfcpp::R_ARM_THM_JUMP6:
8106 case elfcpp::R_ARM_THM_JUMP11:
8107 case elfcpp::R_ARM_THM_JUMP8:
8108 // All the relocation above are branches except for the PREL31 ones.
8109 // A PREL31 relocation can point to a personality function in a shared
8110 // library. In that case we want to use a PLT because we want to
8111 // call the personality routine and the dyanmic linkers we care about
8112 // do not support dynamic PREL31 relocations. An REL31 relocation may
8113 // point to a function whose unwinding behaviour is being described but
8114 // we will not mistakenly generate a PLT for that because we should use
8115 // a local section symbol.
8117 // If the symbol is fully resolved, this is just a relative
8118 // local reloc. Otherwise we need a PLT entry.
8119 if (gsym->final_value_is_known())
8120 break;
8121 // If building a shared library, we can also skip the PLT entry
8122 // if the symbol is defined in the output file and is protected
8123 // or hidden.
8124 if (gsym->is_defined()
8125 && !gsym->is_from_dynobj()
8126 && !gsym->is_preemptible())
8127 break;
8128 target->make_plt_entry(symtab, layout, gsym);
8129 break;
8131 case elfcpp::R_ARM_GOT_BREL:
8132 case elfcpp::R_ARM_GOT_ABS:
8133 case elfcpp::R_ARM_GOT_PREL:
8135 // The symbol requires a GOT entry.
8136 Arm_output_data_got<big_endian>* got =
8137 target->got_section(symtab, layout);
8138 if (gsym->final_value_is_known())
8139 got->add_global(gsym, GOT_TYPE_STANDARD);
8140 else
8142 // If this symbol is not fully resolved, we need to add a
8143 // GOT entry with a dynamic relocation.
8144 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8145 if (gsym->is_from_dynobj()
8146 || gsym->is_undefined()
8147 || gsym->is_preemptible())
8148 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8149 rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8150 else
8152 if (got->add_global(gsym, GOT_TYPE_STANDARD))
8153 rel_dyn->add_global_relative(
8154 gsym, elfcpp::R_ARM_RELATIVE, got,
8155 gsym->got_offset(GOT_TYPE_STANDARD));
8159 break;
8161 case elfcpp::R_ARM_TARGET1:
8162 case elfcpp::R_ARM_TARGET2:
8163 // These should have been mapped to other types already.
8164 // Fall through.
8165 case elfcpp::R_ARM_COPY:
8166 case elfcpp::R_ARM_GLOB_DAT:
8167 case elfcpp::R_ARM_JUMP_SLOT:
8168 case elfcpp::R_ARM_RELATIVE:
8169 // These are relocations which should only be seen by the
8170 // dynamic linker, and should never be seen here.
8171 gold_error(_("%s: unexpected reloc %u in object file"),
8172 object->name().c_str(), r_type);
8173 break;
8175 // These are initial tls relocs, which are expected when
8176 // linking.
8177 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8178 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8179 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8180 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8181 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8183 const bool is_final = gsym->final_value_is_known();
8184 const tls::Tls_optimization optimized_type
8185 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8186 switch (r_type)
8188 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8189 if (optimized_type == tls::TLSOPT_NONE)
8191 // Create a pair of GOT entries for the module index and
8192 // dtv-relative offset.
8193 Arm_output_data_got<big_endian>* got
8194 = target->got_section(symtab, layout);
8195 if (!parameters->doing_static_link())
8196 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8197 target->rel_dyn_section(layout),
8198 elfcpp::R_ARM_TLS_DTPMOD32,
8199 elfcpp::R_ARM_TLS_DTPOFF32);
8200 else
8201 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8203 else
8204 // FIXME: TLS optimization not supported yet.
8205 gold_unreachable();
8206 break;
8208 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8209 if (optimized_type == tls::TLSOPT_NONE)
8211 // Create a GOT entry for the module index.
8212 target->got_mod_index_entry(symtab, layout, object);
8214 else
8215 // FIXME: TLS optimization not supported yet.
8216 gold_unreachable();
8217 break;
8219 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8220 break;
8222 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8223 layout->set_has_static_tls();
8224 if (optimized_type == tls::TLSOPT_NONE)
8226 // Create a GOT entry for the tp-relative offset.
8227 Arm_output_data_got<big_endian>* got
8228 = target->got_section(symtab, layout);
8229 if (!parameters->doing_static_link())
8230 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
8231 target->rel_dyn_section(layout),
8232 elfcpp::R_ARM_TLS_TPOFF32);
8233 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
8235 got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
8236 unsigned int got_offset =
8237 gsym->got_offset(GOT_TYPE_TLS_OFFSET);
8238 got->add_static_reloc(got_offset,
8239 elfcpp::R_ARM_TLS_TPOFF32, gsym);
8242 else
8243 // FIXME: TLS optimization not supported yet.
8244 gold_unreachable();
8245 break;
8247 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8248 layout->set_has_static_tls();
8249 if (parameters->options().shared())
8251 // We need to create a dynamic relocation.
8252 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8253 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
8254 output_section, object,
8255 data_shndx, reloc.get_r_offset());
8257 break;
8259 default:
8260 gold_unreachable();
8263 break;
8265 default:
8266 unsupported_reloc_global(object, r_type, gsym);
8267 break;
8271 // Process relocations for gc.
8273 template<bool big_endian>
8274 void
8275 Target_arm<big_endian>::gc_process_relocs(Symbol_table* symtab,
8276 Layout* layout,
8277 Sized_relobj<32, big_endian>* object,
8278 unsigned int data_shndx,
8279 unsigned int,
8280 const unsigned char* prelocs,
8281 size_t reloc_count,
8282 Output_section* output_section,
8283 bool needs_special_offset_handling,
8284 size_t local_symbol_count,
8285 const unsigned char* plocal_symbols)
8287 typedef Target_arm<big_endian> Arm;
8288 typedef typename Target_arm<big_endian>::Scan Scan;
8290 gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
8291 typename Target_arm::Relocatable_size_for_reloc>(
8292 symtab,
8293 layout,
8294 this,
8295 object,
8296 data_shndx,
8297 prelocs,
8298 reloc_count,
8299 output_section,
8300 needs_special_offset_handling,
8301 local_symbol_count,
8302 plocal_symbols);
8305 // Scan relocations for a section.
8307 template<bool big_endian>
8308 void
8309 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
8310 Layout* layout,
8311 Sized_relobj<32, big_endian>* object,
8312 unsigned int data_shndx,
8313 unsigned int sh_type,
8314 const unsigned char* prelocs,
8315 size_t reloc_count,
8316 Output_section* output_section,
8317 bool needs_special_offset_handling,
8318 size_t local_symbol_count,
8319 const unsigned char* plocal_symbols)
8321 typedef typename Target_arm<big_endian>::Scan Scan;
8322 if (sh_type == elfcpp::SHT_RELA)
8324 gold_error(_("%s: unsupported RELA reloc section"),
8325 object->name().c_str());
8326 return;
8329 gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
8330 symtab,
8331 layout,
8332 this,
8333 object,
8334 data_shndx,
8335 prelocs,
8336 reloc_count,
8337 output_section,
8338 needs_special_offset_handling,
8339 local_symbol_count,
8340 plocal_symbols);
8343 // Finalize the sections.
8345 template<bool big_endian>
8346 void
8347 Target_arm<big_endian>::do_finalize_sections(
8348 Layout* layout,
8349 const Input_objects* input_objects,
8350 Symbol_table* symtab)
8352 bool merged_any_attributes = false;
8353 // Merge processor-specific flags.
8354 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
8355 p != input_objects->relobj_end();
8356 ++p)
8358 Arm_relobj<big_endian>* arm_relobj =
8359 Arm_relobj<big_endian>::as_arm_relobj(*p);
8360 if (arm_relobj->merge_flags_and_attributes())
8362 this->merge_processor_specific_flags(
8363 arm_relobj->name(),
8364 arm_relobj->processor_specific_flags());
8365 this->merge_object_attributes(arm_relobj->name().c_str(),
8366 arm_relobj->attributes_section_data());
8367 merged_any_attributes = true;
8371 for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
8372 p != input_objects->dynobj_end();
8373 ++p)
8375 Arm_dynobj<big_endian>* arm_dynobj =
8376 Arm_dynobj<big_endian>::as_arm_dynobj(*p);
8377 this->merge_processor_specific_flags(
8378 arm_dynobj->name(),
8379 arm_dynobj->processor_specific_flags());
8380 this->merge_object_attributes(arm_dynobj->name().c_str(),
8381 arm_dynobj->attributes_section_data());
8382 merged_any_attributes = true;
8385 // Create an empty uninitialized attribute section if we still don't have it
8386 // at this moment. This happens if there is no attributes sections in all
8387 // inputs.
8388 if (this->attributes_section_data_ == NULL)
8389 this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
8391 // Check BLX use.
8392 const Object_attribute* cpu_arch_attr =
8393 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
8394 if (cpu_arch_attr->int_value() > elfcpp::TAG_CPU_ARCH_V4)
8395 this->set_may_use_blx(true);
8397 // Check if we need to use Cortex-A8 workaround.
8398 if (parameters->options().user_set_fix_cortex_a8())
8399 this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
8400 else
8402 // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
8403 // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
8404 // profile.
8405 const Object_attribute* cpu_arch_profile_attr =
8406 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
8407 this->fix_cortex_a8_ =
8408 (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
8409 && (cpu_arch_profile_attr->int_value() == 'A'
8410 || cpu_arch_profile_attr->int_value() == 0));
8413 // Check if we can use V4BX interworking.
8414 // The V4BX interworking stub contains BX instruction,
8415 // which is not specified for some profiles.
8416 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
8417 && !this->may_use_blx())
8418 gold_error(_("unable to provide V4BX reloc interworking fix up; "
8419 "the target profile does not support BX instruction"));
8421 // Fill in some more dynamic tags.
8422 const Reloc_section* rel_plt = (this->plt_ == NULL
8423 ? NULL
8424 : this->plt_->rel_plt());
8425 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
8426 this->rel_dyn_, true, false);
8428 // Emit any relocs we saved in an attempt to avoid generating COPY
8429 // relocs.
8430 if (this->copy_relocs_.any_saved_relocs())
8431 this->copy_relocs_.emit(this->rel_dyn_section(layout));
8433 // Handle the .ARM.exidx section.
8434 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8436 if (!parameters->options().relocatable())
8438 if (exidx_section != NULL
8439 && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
8441 // Create __exidx_start and __exdix_end symbols.
8442 symtab->define_in_output_data("__exidx_start", NULL,
8443 Symbol_table::PREDEFINED,
8444 exidx_section, 0, 0, elfcpp::STT_OBJECT,
8445 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
8446 0, false, true);
8447 symtab->define_in_output_data("__exidx_end", NULL,
8448 Symbol_table::PREDEFINED,
8449 exidx_section, 0, 0, elfcpp::STT_OBJECT,
8450 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
8451 0, true, true);
8453 // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8454 // the .ARM.exidx section.
8455 if (!layout->script_options()->saw_phdrs_clause())
8457 gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
8459 == NULL);
8460 Output_segment* exidx_segment =
8461 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8462 exidx_segment->add_output_section_to_nonload(exidx_section,
8463 elfcpp::PF_R);
8466 else
8468 symtab->define_as_constant("__exidx_start", NULL,
8469 Symbol_table::PREDEFINED,
8470 0, 0, elfcpp::STT_OBJECT,
8471 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8472 true, false);
8473 symtab->define_as_constant("__exidx_end", NULL,
8474 Symbol_table::PREDEFINED,
8475 0, 0, elfcpp::STT_OBJECT,
8476 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8477 true, false);
8481 // Create an .ARM.attributes section if we have merged any attributes
8482 // from inputs.
8483 if (merged_any_attributes)
8485 Output_attributes_section_data* attributes_section =
8486 new Output_attributes_section_data(*this->attributes_section_data_);
8487 layout->add_output_section_data(".ARM.attributes",
8488 elfcpp::SHT_ARM_ATTRIBUTES, 0,
8489 attributes_section, ORDER_INVALID,
8490 false);
8493 // Fix up links in section EXIDX headers.
8494 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
8495 p != layout->section_list().end();
8496 ++p)
8497 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
8499 Arm_output_section<big_endian>* os =
8500 Arm_output_section<big_endian>::as_arm_output_section(*p);
8501 os->set_exidx_section_link();
8505 // Return whether a direct absolute static relocation needs to be applied.
8506 // In cases where Scan::local() or Scan::global() has created
8507 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8508 // of the relocation is carried in the data, and we must not
8509 // apply the static relocation.
8511 template<bool big_endian>
8512 inline bool
8513 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8514 const Sized_symbol<32>* gsym,
8515 int ref_flags,
8516 bool is_32bit,
8517 Output_section* output_section)
8519 // If the output section is not allocated, then we didn't call
8520 // scan_relocs, we didn't create a dynamic reloc, and we must apply
8521 // the reloc here.
8522 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8523 return true;
8525 // For local symbols, we will have created a non-RELATIVE dynamic
8526 // relocation only if (a) the output is position independent,
8527 // (b) the relocation is absolute (not pc- or segment-relative), and
8528 // (c) the relocation is not 32 bits wide.
8529 if (gsym == NULL)
8530 return !(parameters->options().output_is_position_independent()
8531 && (ref_flags & Symbol::ABSOLUTE_REF)
8532 && !is_32bit);
8534 // For global symbols, we use the same helper routines used in the
8535 // scan pass. If we did not create a dynamic relocation, or if we
8536 // created a RELATIVE dynamic relocation, we should apply the static
8537 // relocation.
8538 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8539 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8540 && gsym->can_use_relative_reloc(ref_flags
8541 & Symbol::FUNCTION_CALL);
8542 return !has_dyn || is_rel;
8545 // Perform a relocation.
8547 template<bool big_endian>
8548 inline bool
8549 Target_arm<big_endian>::Relocate::relocate(
8550 const Relocate_info<32, big_endian>* relinfo,
8551 Target_arm* target,
8552 Output_section* output_section,
8553 size_t relnum,
8554 const elfcpp::Rel<32, big_endian>& rel,
8555 unsigned int r_type,
8556 const Sized_symbol<32>* gsym,
8557 const Symbol_value<32>* psymval,
8558 unsigned char* view,
8559 Arm_address address,
8560 section_size_type view_size)
8562 typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8564 r_type = get_real_reloc_type(r_type);
8565 const Arm_reloc_property* reloc_property =
8566 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8567 if (reloc_property == NULL)
8569 std::string reloc_name =
8570 arm_reloc_property_table->reloc_name_in_error_message(r_type);
8571 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8572 _("cannot relocate %s in object file"),
8573 reloc_name.c_str());
8574 return true;
8577 const Arm_relobj<big_endian>* object =
8578 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8580 // If the final branch target of a relocation is THUMB instruction, this
8581 // is 1. Otherwise it is 0.
8582 Arm_address thumb_bit = 0;
8583 Symbol_value<32> symval;
8584 bool is_weakly_undefined_without_plt = false;
8585 bool have_got_offset = false;
8586 unsigned int got_offset = 0;
8588 // If the relocation uses the GOT entry of a symbol instead of the symbol
8589 // itself, we don't care about whether the symbol is defined or what kind
8590 // of symbol it is.
8591 if (reloc_property->uses_got_entry())
8593 // Get the GOT offset.
8594 // The GOT pointer points to the end of the GOT section.
8595 // We need to subtract the size of the GOT section to get
8596 // the actual offset to use in the relocation.
8597 // TODO: We should move GOT offset computing code in TLS relocations
8598 // to here.
8599 switch (r_type)
8601 case elfcpp::R_ARM_GOT_BREL:
8602 case elfcpp::R_ARM_GOT_PREL:
8603 if (gsym != NULL)
8605 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8606 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8607 - target->got_size());
8609 else
8611 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8612 gold_assert(object->local_has_got_offset(r_sym,
8613 GOT_TYPE_STANDARD));
8614 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8615 - target->got_size());
8617 have_got_offset = true;
8618 break;
8620 default:
8621 break;
8624 else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8626 if (gsym != NULL)
8628 // This is a global symbol. Determine if we use PLT and if the
8629 // final target is THUMB.
8630 if (gsym->use_plt_offset(reloc_is_non_pic(r_type)))
8632 // This uses a PLT, change the symbol value.
8633 symval.set_output_value(target->plt_section()->address()
8634 + gsym->plt_offset());
8635 psymval = &symval;
8637 else if (gsym->is_weak_undefined())
8639 // This is a weakly undefined symbol and we do not use PLT
8640 // for this relocation. A branch targeting this symbol will
8641 // be converted into an NOP.
8642 is_weakly_undefined_without_plt = true;
8644 else if (gsym->is_undefined() && reloc_property->uses_symbol())
8646 // This relocation uses the symbol value but the symbol is
8647 // undefined. Exit early and have the caller reporting an
8648 // error.
8649 return true;
8651 else
8653 // Set thumb bit if symbol:
8654 // -Has type STT_ARM_TFUNC or
8655 // -Has type STT_FUNC, is defined and with LSB in value set.
8656 thumb_bit =
8657 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8658 || (gsym->type() == elfcpp::STT_FUNC
8659 && !gsym->is_undefined()
8660 && ((psymval->value(object, 0) & 1) != 0)))
8662 : 0);
8665 else
8667 // This is a local symbol. Determine if the final target is THUMB.
8668 // We saved this information when all the local symbols were read.
8669 elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8670 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8671 thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8674 else
8676 // This is a fake relocation synthesized for a stub. It does not have
8677 // a real symbol. We just look at the LSB of the symbol value to
8678 // determine if the target is THUMB or not.
8679 thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8682 // Strip LSB if this points to a THUMB target.
8683 if (thumb_bit != 0
8684 && reloc_property->uses_thumb_bit()
8685 && ((psymval->value(object, 0) & 1) != 0))
8687 Arm_address stripped_value =
8688 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8689 symval.set_output_value(stripped_value);
8690 psymval = &symval;
8693 // To look up relocation stubs, we need to pass the symbol table index of
8694 // a local symbol.
8695 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8697 // Get the addressing origin of the output segment defining the
8698 // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8699 Arm_address sym_origin = 0;
8700 if (reloc_property->uses_symbol_base())
8702 if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8703 // R_ARM_BASE_ABS with the NULL symbol will give the
8704 // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8705 // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8706 sym_origin = target->got_plt_section()->address();
8707 else if (gsym == NULL)
8708 sym_origin = 0;
8709 else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8710 sym_origin = gsym->output_segment()->vaddr();
8711 else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
8712 sym_origin = gsym->output_data()->address();
8714 // TODO: Assumes the segment base to be zero for the global symbols
8715 // till the proper support for the segment-base-relative addressing
8716 // will be implemented. This is consistent with GNU ld.
8719 // For relative addressing relocation, find out the relative address base.
8720 Arm_address relative_address_base = 0;
8721 switch(reloc_property->relative_address_base())
8723 case Arm_reloc_property::RAB_NONE:
8724 // Relocations with relative address bases RAB_TLS and RAB_tp are
8725 // handled by relocate_tls. So we do not need to do anything here.
8726 case Arm_reloc_property::RAB_TLS:
8727 case Arm_reloc_property::RAB_tp:
8728 break;
8729 case Arm_reloc_property::RAB_B_S:
8730 relative_address_base = sym_origin;
8731 break;
8732 case Arm_reloc_property::RAB_GOT_ORG:
8733 relative_address_base = target->got_plt_section()->address();
8734 break;
8735 case Arm_reloc_property::RAB_P:
8736 relative_address_base = address;
8737 break;
8738 case Arm_reloc_property::RAB_Pa:
8739 relative_address_base = address & 0xfffffffcU;
8740 break;
8741 default:
8742 gold_unreachable();
8745 typename Arm_relocate_functions::Status reloc_status =
8746 Arm_relocate_functions::STATUS_OKAY;
8747 bool check_overflow = reloc_property->checks_overflow();
8748 switch (r_type)
8750 case elfcpp::R_ARM_NONE:
8751 break;
8753 case elfcpp::R_ARM_ABS8:
8754 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8755 output_section))
8756 reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
8757 break;
8759 case elfcpp::R_ARM_ABS12:
8760 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8761 output_section))
8762 reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
8763 break;
8765 case elfcpp::R_ARM_ABS16:
8766 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8767 output_section))
8768 reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
8769 break;
8771 case elfcpp::R_ARM_ABS32:
8772 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
8773 output_section))
8774 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8775 thumb_bit);
8776 break;
8778 case elfcpp::R_ARM_ABS32_NOI:
8779 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
8780 output_section))
8781 // No thumb bit for this relocation: (S + A)
8782 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8784 break;
8786 case elfcpp::R_ARM_MOVW_ABS_NC:
8787 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8788 output_section))
8789 reloc_status = Arm_relocate_functions::movw(view, object, psymval,
8790 0, thumb_bit,
8791 check_overflow);
8792 break;
8794 case elfcpp::R_ARM_MOVT_ABS:
8795 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8796 output_section))
8797 reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
8798 break;
8800 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8801 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8802 output_section))
8803 reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
8804 0, thumb_bit, false);
8805 break;
8807 case elfcpp::R_ARM_THM_MOVT_ABS:
8808 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8809 output_section))
8810 reloc_status = Arm_relocate_functions::thm_movt(view, object,
8811 psymval, 0);
8812 break;
8814 case elfcpp::R_ARM_MOVW_PREL_NC:
8815 case elfcpp::R_ARM_MOVW_BREL_NC:
8816 case elfcpp::R_ARM_MOVW_BREL:
8817 reloc_status =
8818 Arm_relocate_functions::movw(view, object, psymval,
8819 relative_address_base, thumb_bit,
8820 check_overflow);
8821 break;
8823 case elfcpp::R_ARM_MOVT_PREL:
8824 case elfcpp::R_ARM_MOVT_BREL:
8825 reloc_status =
8826 Arm_relocate_functions::movt(view, object, psymval,
8827 relative_address_base);
8828 break;
8830 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8831 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8832 case elfcpp::R_ARM_THM_MOVW_BREL:
8833 reloc_status =
8834 Arm_relocate_functions::thm_movw(view, object, psymval,
8835 relative_address_base,
8836 thumb_bit, check_overflow);
8837 break;
8839 case elfcpp::R_ARM_THM_MOVT_PREL:
8840 case elfcpp::R_ARM_THM_MOVT_BREL:
8841 reloc_status =
8842 Arm_relocate_functions::thm_movt(view, object, psymval,
8843 relative_address_base);
8844 break;
8846 case elfcpp::R_ARM_REL32:
8847 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
8848 address, thumb_bit);
8849 break;
8851 case elfcpp::R_ARM_THM_ABS5:
8852 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8853 output_section))
8854 reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
8855 break;
8857 // Thumb long branches.
8858 case elfcpp::R_ARM_THM_CALL:
8859 case elfcpp::R_ARM_THM_XPC22:
8860 case elfcpp::R_ARM_THM_JUMP24:
8861 reloc_status =
8862 Arm_relocate_functions::thumb_branch_common(
8863 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
8864 thumb_bit, is_weakly_undefined_without_plt);
8865 break;
8867 case elfcpp::R_ARM_GOTOFF32:
8869 Arm_address got_origin;
8870 got_origin = target->got_plt_section()->address();
8871 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
8872 got_origin, thumb_bit);
8874 break;
8876 case elfcpp::R_ARM_BASE_PREL:
8877 gold_assert(gsym != NULL);
8878 reloc_status =
8879 Arm_relocate_functions::base_prel(view, sym_origin, address);
8880 break;
8882 case elfcpp::R_ARM_BASE_ABS:
8884 if (!should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8885 output_section))
8886 break;
8888 reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
8890 break;
8892 case elfcpp::R_ARM_GOT_BREL:
8893 gold_assert(have_got_offset);
8894 reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
8895 break;
8897 case elfcpp::R_ARM_GOT_PREL:
8898 gold_assert(have_got_offset);
8899 // Get the address origin for GOT PLT, which is allocated right
8900 // after the GOT section, to calculate an absolute address of
8901 // the symbol GOT entry (got_origin + got_offset).
8902 Arm_address got_origin;
8903 got_origin = target->got_plt_section()->address();
8904 reloc_status = Arm_relocate_functions::got_prel(view,
8905 got_origin + got_offset,
8906 address);
8907 break;
8909 case elfcpp::R_ARM_PLT32:
8910 case elfcpp::R_ARM_CALL:
8911 case elfcpp::R_ARM_JUMP24:
8912 case elfcpp::R_ARM_XPC25:
8913 gold_assert(gsym == NULL
8914 || gsym->has_plt_offset()
8915 || gsym->final_value_is_known()
8916 || (gsym->is_defined()
8917 && !gsym->is_from_dynobj()
8918 && !gsym->is_preemptible()));
8919 reloc_status =
8920 Arm_relocate_functions::arm_branch_common(
8921 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
8922 thumb_bit, is_weakly_undefined_without_plt);
8923 break;
8925 case elfcpp::R_ARM_THM_JUMP19:
8926 reloc_status =
8927 Arm_relocate_functions::thm_jump19(view, object, psymval, address,
8928 thumb_bit);
8929 break;
8931 case elfcpp::R_ARM_THM_JUMP6:
8932 reloc_status =
8933 Arm_relocate_functions::thm_jump6(view, object, psymval, address);
8934 break;
8936 case elfcpp::R_ARM_THM_JUMP8:
8937 reloc_status =
8938 Arm_relocate_functions::thm_jump8(view, object, psymval, address);
8939 break;
8941 case elfcpp::R_ARM_THM_JUMP11:
8942 reloc_status =
8943 Arm_relocate_functions::thm_jump11(view, object, psymval, address);
8944 break;
8946 case elfcpp::R_ARM_PREL31:
8947 reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
8948 address, thumb_bit);
8949 break;
8951 case elfcpp::R_ARM_V4BX:
8952 if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
8954 const bool is_v4bx_interworking =
8955 (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
8956 reloc_status =
8957 Arm_relocate_functions::v4bx(relinfo, view, object, address,
8958 is_v4bx_interworking);
8960 break;
8962 case elfcpp::R_ARM_THM_PC8:
8963 reloc_status =
8964 Arm_relocate_functions::thm_pc8(view, object, psymval, address);
8965 break;
8967 case elfcpp::R_ARM_THM_PC12:
8968 reloc_status =
8969 Arm_relocate_functions::thm_pc12(view, object, psymval, address);
8970 break;
8972 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8973 reloc_status =
8974 Arm_relocate_functions::thm_alu11(view, object, psymval, address,
8975 thumb_bit);
8976 break;
8978 case elfcpp::R_ARM_ALU_PC_G0_NC:
8979 case elfcpp::R_ARM_ALU_PC_G0:
8980 case elfcpp::R_ARM_ALU_PC_G1_NC:
8981 case elfcpp::R_ARM_ALU_PC_G1:
8982 case elfcpp::R_ARM_ALU_PC_G2:
8983 case elfcpp::R_ARM_ALU_SB_G0_NC:
8984 case elfcpp::R_ARM_ALU_SB_G0:
8985 case elfcpp::R_ARM_ALU_SB_G1_NC:
8986 case elfcpp::R_ARM_ALU_SB_G1:
8987 case elfcpp::R_ARM_ALU_SB_G2:
8988 reloc_status =
8989 Arm_relocate_functions::arm_grp_alu(view, object, psymval,
8990 reloc_property->group_index(),
8991 relative_address_base,
8992 thumb_bit, check_overflow);
8993 break;
8995 case elfcpp::R_ARM_LDR_PC_G0:
8996 case elfcpp::R_ARM_LDR_PC_G1:
8997 case elfcpp::R_ARM_LDR_PC_G2:
8998 case elfcpp::R_ARM_LDR_SB_G0:
8999 case elfcpp::R_ARM_LDR_SB_G1:
9000 case elfcpp::R_ARM_LDR_SB_G2:
9001 reloc_status =
9002 Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9003 reloc_property->group_index(),
9004 relative_address_base);
9005 break;
9007 case elfcpp::R_ARM_LDRS_PC_G0:
9008 case elfcpp::R_ARM_LDRS_PC_G1:
9009 case elfcpp::R_ARM_LDRS_PC_G2:
9010 case elfcpp::R_ARM_LDRS_SB_G0:
9011 case elfcpp::R_ARM_LDRS_SB_G1:
9012 case elfcpp::R_ARM_LDRS_SB_G2:
9013 reloc_status =
9014 Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9015 reloc_property->group_index(),
9016 relative_address_base);
9017 break;
9019 case elfcpp::R_ARM_LDC_PC_G0:
9020 case elfcpp::R_ARM_LDC_PC_G1:
9021 case elfcpp::R_ARM_LDC_PC_G2:
9022 case elfcpp::R_ARM_LDC_SB_G0:
9023 case elfcpp::R_ARM_LDC_SB_G1:
9024 case elfcpp::R_ARM_LDC_SB_G2:
9025 reloc_status =
9026 Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9027 reloc_property->group_index(),
9028 relative_address_base);
9029 break;
9031 // These are initial tls relocs, which are expected when
9032 // linking.
9033 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9034 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9035 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9036 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9037 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9038 reloc_status =
9039 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9040 view, address, view_size);
9041 break;
9043 default:
9044 gold_unreachable();
9047 // Report any errors.
9048 switch (reloc_status)
9050 case Arm_relocate_functions::STATUS_OKAY:
9051 break;
9052 case Arm_relocate_functions::STATUS_OVERFLOW:
9053 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9054 _("relocation overflow in %s"),
9055 reloc_property->name().c_str());
9056 break;
9057 case Arm_relocate_functions::STATUS_BAD_RELOC:
9058 gold_error_at_location(
9059 relinfo,
9060 relnum,
9061 rel.get_r_offset(),
9062 _("unexpected opcode while processing relocation %s"),
9063 reloc_property->name().c_str());
9064 break;
9065 default:
9066 gold_unreachable();
9069 return true;
9072 // Perform a TLS relocation.
9074 template<bool big_endian>
9075 inline typename Arm_relocate_functions<big_endian>::Status
9076 Target_arm<big_endian>::Relocate::relocate_tls(
9077 const Relocate_info<32, big_endian>* relinfo,
9078 Target_arm<big_endian>* target,
9079 size_t relnum,
9080 const elfcpp::Rel<32, big_endian>& rel,
9081 unsigned int r_type,
9082 const Sized_symbol<32>* gsym,
9083 const Symbol_value<32>* psymval,
9084 unsigned char* view,
9085 elfcpp::Elf_types<32>::Elf_Addr address,
9086 section_size_type /*view_size*/ )
9088 typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9089 typedef Relocate_functions<32, big_endian> RelocFuncs;
9090 Output_segment* tls_segment = relinfo->layout->tls_segment();
9092 const Sized_relobj<32, big_endian>* object = relinfo->object;
9094 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9096 const bool is_final = (gsym == NULL
9097 ? !parameters->options().shared()
9098 : gsym->final_value_is_known());
9099 const tls::Tls_optimization optimized_type
9100 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9101 switch (r_type)
9103 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9105 unsigned int got_type = GOT_TYPE_TLS_PAIR;
9106 unsigned int got_offset;
9107 if (gsym != NULL)
9109 gold_assert(gsym->has_got_offset(got_type));
9110 got_offset = gsym->got_offset(got_type) - target->got_size();
9112 else
9114 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9115 gold_assert(object->local_has_got_offset(r_sym, got_type));
9116 got_offset = (object->local_got_offset(r_sym, got_type)
9117 - target->got_size());
9119 if (optimized_type == tls::TLSOPT_NONE)
9121 Arm_address got_entry =
9122 target->got_plt_section()->address() + got_offset;
9124 // Relocate the field with the PC relative offset of the pair of
9125 // GOT entries.
9126 RelocFuncs::pcrel32(view, got_entry, address);
9127 return ArmRelocFuncs::STATUS_OKAY;
9130 break;
9132 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9133 if (optimized_type == tls::TLSOPT_NONE)
9135 // Relocate the field with the offset of the GOT entry for
9136 // the module index.
9137 unsigned int got_offset;
9138 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9139 - target->got_size());
9140 Arm_address got_entry =
9141 target->got_plt_section()->address() + got_offset;
9143 // Relocate the field with the PC relative offset of the pair of
9144 // GOT entries.
9145 RelocFuncs::pcrel32(view, got_entry, address);
9146 return ArmRelocFuncs::STATUS_OKAY;
9148 break;
9150 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9151 RelocFuncs::rel32(view, value);
9152 return ArmRelocFuncs::STATUS_OKAY;
9154 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9155 if (optimized_type == tls::TLSOPT_NONE)
9157 // Relocate the field with the offset of the GOT entry for
9158 // the tp-relative offset of the symbol.
9159 unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9160 unsigned int got_offset;
9161 if (gsym != NULL)
9163 gold_assert(gsym->has_got_offset(got_type));
9164 got_offset = gsym->got_offset(got_type);
9166 else
9168 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9169 gold_assert(object->local_has_got_offset(r_sym, got_type));
9170 got_offset = object->local_got_offset(r_sym, got_type);
9173 // All GOT offsets are relative to the end of the GOT.
9174 got_offset -= target->got_size();
9176 Arm_address got_entry =
9177 target->got_plt_section()->address() + got_offset;
9179 // Relocate the field with the PC relative offset of the GOT entry.
9180 RelocFuncs::pcrel32(view, got_entry, address);
9181 return ArmRelocFuncs::STATUS_OKAY;
9183 break;
9185 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9186 // If we're creating a shared library, a dynamic relocation will
9187 // have been created for this location, so do not apply it now.
9188 if (!parameters->options().shared())
9190 gold_assert(tls_segment != NULL);
9192 // $tp points to the TCB, which is followed by the TLS, so we
9193 // need to add TCB size to the offset.
9194 Arm_address aligned_tcb_size =
9195 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9196 RelocFuncs::rel32(view, value + aligned_tcb_size);
9199 return ArmRelocFuncs::STATUS_OKAY;
9201 default:
9202 gold_unreachable();
9205 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9206 _("unsupported reloc %u"),
9207 r_type);
9208 return ArmRelocFuncs::STATUS_BAD_RELOC;
9211 // Relocate section data.
9213 template<bool big_endian>
9214 void
9215 Target_arm<big_endian>::relocate_section(
9216 const Relocate_info<32, big_endian>* relinfo,
9217 unsigned int sh_type,
9218 const unsigned char* prelocs,
9219 size_t reloc_count,
9220 Output_section* output_section,
9221 bool needs_special_offset_handling,
9222 unsigned char* view,
9223 Arm_address address,
9224 section_size_type view_size,
9225 const Reloc_symbol_changes* reloc_symbol_changes)
9227 typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
9228 gold_assert(sh_type == elfcpp::SHT_REL);
9230 // See if we are relocating a relaxed input section. If so, the view
9231 // covers the whole output section and we need to adjust accordingly.
9232 if (needs_special_offset_handling)
9234 const Output_relaxed_input_section* poris =
9235 output_section->find_relaxed_input_section(relinfo->object,
9236 relinfo->data_shndx);
9237 if (poris != NULL)
9239 Arm_address section_address = poris->address();
9240 section_size_type section_size = poris->data_size();
9242 gold_assert((section_address >= address)
9243 && ((section_address + section_size)
9244 <= (address + view_size)));
9246 off_t offset = section_address - address;
9247 view += offset;
9248 address += offset;
9249 view_size = section_size;
9253 gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
9254 Arm_relocate>(
9255 relinfo,
9256 this,
9257 prelocs,
9258 reloc_count,
9259 output_section,
9260 needs_special_offset_handling,
9261 view,
9262 address,
9263 view_size,
9264 reloc_symbol_changes);
9267 // Return the size of a relocation while scanning during a relocatable
9268 // link.
9270 template<bool big_endian>
9271 unsigned int
9272 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
9273 unsigned int r_type,
9274 Relobj* object)
9276 r_type = get_real_reloc_type(r_type);
9277 const Arm_reloc_property* arp =
9278 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9279 if (arp != NULL)
9280 return arp->size();
9281 else
9283 std::string reloc_name =
9284 arm_reloc_property_table->reloc_name_in_error_message(r_type);
9285 gold_error(_("%s: unexpected %s in object file"),
9286 object->name().c_str(), reloc_name.c_str());
9287 return 0;
9291 // Scan the relocs during a relocatable link.
9293 template<bool big_endian>
9294 void
9295 Target_arm<big_endian>::scan_relocatable_relocs(
9296 Symbol_table* symtab,
9297 Layout* layout,
9298 Sized_relobj<32, big_endian>* object,
9299 unsigned int data_shndx,
9300 unsigned int sh_type,
9301 const unsigned char* prelocs,
9302 size_t reloc_count,
9303 Output_section* output_section,
9304 bool needs_special_offset_handling,
9305 size_t local_symbol_count,
9306 const unsigned char* plocal_symbols,
9307 Relocatable_relocs* rr)
9309 gold_assert(sh_type == elfcpp::SHT_REL);
9311 typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
9312 Relocatable_size_for_reloc> Scan_relocatable_relocs;
9314 gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
9315 Scan_relocatable_relocs>(
9316 symtab,
9317 layout,
9318 object,
9319 data_shndx,
9320 prelocs,
9321 reloc_count,
9322 output_section,
9323 needs_special_offset_handling,
9324 local_symbol_count,
9325 plocal_symbols,
9326 rr);
9329 // Relocate a section during a relocatable link.
9331 template<bool big_endian>
9332 void
9333 Target_arm<big_endian>::relocate_for_relocatable(
9334 const Relocate_info<32, big_endian>* relinfo,
9335 unsigned int sh_type,
9336 const unsigned char* prelocs,
9337 size_t reloc_count,
9338 Output_section* output_section,
9339 off_t offset_in_output_section,
9340 const Relocatable_relocs* rr,
9341 unsigned char* view,
9342 Arm_address view_address,
9343 section_size_type view_size,
9344 unsigned char* reloc_view,
9345 section_size_type reloc_view_size)
9347 gold_assert(sh_type == elfcpp::SHT_REL);
9349 gold::relocate_for_relocatable<32, big_endian, elfcpp::SHT_REL>(
9350 relinfo,
9351 prelocs,
9352 reloc_count,
9353 output_section,
9354 offset_in_output_section,
9356 view,
9357 view_address,
9358 view_size,
9359 reloc_view,
9360 reloc_view_size);
9363 // Perform target-specific processing in a relocatable link. This is
9364 // only used if we use the relocation strategy RELOC_SPECIAL.
9366 template<bool big_endian>
9367 void
9368 Target_arm<big_endian>::relocate_special_relocatable(
9369 const Relocate_info<32, big_endian>* relinfo,
9370 unsigned int sh_type,
9371 const unsigned char* preloc_in,
9372 size_t relnum,
9373 Output_section* output_section,
9374 off_t offset_in_output_section,
9375 unsigned char* view,
9376 elfcpp::Elf_types<32>::Elf_Addr view_address,
9377 section_size_type,
9378 unsigned char* preloc_out)
9380 // We can only handle REL type relocation sections.
9381 gold_assert(sh_type == elfcpp::SHT_REL);
9383 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
9384 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
9385 Reltype_write;
9386 const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
9388 const Arm_relobj<big_endian>* object =
9389 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9390 const unsigned int local_count = object->local_symbol_count();
9392 Reltype reloc(preloc_in);
9393 Reltype_write reloc_write(preloc_out);
9395 elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
9396 const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9397 const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
9399 const Arm_reloc_property* arp =
9400 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9401 gold_assert(arp != NULL);
9403 // Get the new symbol index.
9404 // We only use RELOC_SPECIAL strategy in local relocations.
9405 gold_assert(r_sym < local_count);
9407 // We are adjusting a section symbol. We need to find
9408 // the symbol table index of the section symbol for
9409 // the output section corresponding to input section
9410 // in which this symbol is defined.
9411 bool is_ordinary;
9412 unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
9413 gold_assert(is_ordinary);
9414 Output_section* os = object->output_section(shndx);
9415 gold_assert(os != NULL);
9416 gold_assert(os->needs_symtab_index());
9417 unsigned int new_symndx = os->symtab_index();
9419 // Get the new offset--the location in the output section where
9420 // this relocation should be applied.
9422 Arm_address offset = reloc.get_r_offset();
9423 Arm_address new_offset;
9424 if (offset_in_output_section != invalid_address)
9425 new_offset = offset + offset_in_output_section;
9426 else
9428 section_offset_type sot_offset =
9429 convert_types<section_offset_type, Arm_address>(offset);
9430 section_offset_type new_sot_offset =
9431 output_section->output_offset(object, relinfo->data_shndx,
9432 sot_offset);
9433 gold_assert(new_sot_offset != -1);
9434 new_offset = new_sot_offset;
9437 // In an object file, r_offset is an offset within the section.
9438 // In an executable or dynamic object, generated by
9439 // --emit-relocs, r_offset is an absolute address.
9440 if (!parameters->options().relocatable())
9442 new_offset += view_address;
9443 if (offset_in_output_section != invalid_address)
9444 new_offset -= offset_in_output_section;
9447 reloc_write.put_r_offset(new_offset);
9448 reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
9450 // Handle the reloc addend.
9451 // The relocation uses a section symbol in the input file.
9452 // We are adjusting it to use a section symbol in the output
9453 // file. The input section symbol refers to some address in
9454 // the input section. We need the relocation in the output
9455 // file to refer to that same address. This adjustment to
9456 // the addend is the same calculation we use for a simple
9457 // absolute relocation for the input section symbol.
9459 const Symbol_value<32>* psymval = object->local_symbol(r_sym);
9461 // Handle THUMB bit.
9462 Symbol_value<32> symval;
9463 Arm_address thumb_bit =
9464 object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9465 if (thumb_bit != 0
9466 && arp->uses_thumb_bit()
9467 && ((psymval->value(object, 0) & 1) != 0))
9469 Arm_address stripped_value =
9470 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9471 symval.set_output_value(stripped_value);
9472 psymval = &symval;
9475 unsigned char* paddend = view + offset;
9476 typename Arm_relocate_functions<big_endian>::Status reloc_status =
9477 Arm_relocate_functions<big_endian>::STATUS_OKAY;
9478 switch (r_type)
9480 case elfcpp::R_ARM_ABS8:
9481 reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
9482 psymval);
9483 break;
9485 case elfcpp::R_ARM_ABS12:
9486 reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
9487 psymval);
9488 break;
9490 case elfcpp::R_ARM_ABS16:
9491 reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
9492 psymval);
9493 break;
9495 case elfcpp::R_ARM_THM_ABS5:
9496 reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
9497 object,
9498 psymval);
9499 break;
9501 case elfcpp::R_ARM_MOVW_ABS_NC:
9502 case elfcpp::R_ARM_MOVW_PREL_NC:
9503 case elfcpp::R_ARM_MOVW_BREL_NC:
9504 case elfcpp::R_ARM_MOVW_BREL:
9505 reloc_status = Arm_relocate_functions<big_endian>::movw(
9506 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9507 break;
9509 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9510 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9511 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9512 case elfcpp::R_ARM_THM_MOVW_BREL:
9513 reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
9514 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9515 break;
9517 case elfcpp::R_ARM_THM_CALL:
9518 case elfcpp::R_ARM_THM_XPC22:
9519 case elfcpp::R_ARM_THM_JUMP24:
9520 reloc_status =
9521 Arm_relocate_functions<big_endian>::thumb_branch_common(
9522 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9523 false);
9524 break;
9526 case elfcpp::R_ARM_PLT32:
9527 case elfcpp::R_ARM_CALL:
9528 case elfcpp::R_ARM_JUMP24:
9529 case elfcpp::R_ARM_XPC25:
9530 reloc_status =
9531 Arm_relocate_functions<big_endian>::arm_branch_common(
9532 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9533 false);
9534 break;
9536 case elfcpp::R_ARM_THM_JUMP19:
9537 reloc_status =
9538 Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
9539 psymval, 0, thumb_bit);
9540 break;
9542 case elfcpp::R_ARM_THM_JUMP6:
9543 reloc_status =
9544 Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
9546 break;
9548 case elfcpp::R_ARM_THM_JUMP8:
9549 reloc_status =
9550 Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
9552 break;
9554 case elfcpp::R_ARM_THM_JUMP11:
9555 reloc_status =
9556 Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
9558 break;
9560 case elfcpp::R_ARM_PREL31:
9561 reloc_status =
9562 Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
9563 thumb_bit);
9564 break;
9566 case elfcpp::R_ARM_THM_PC8:
9567 reloc_status =
9568 Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
9570 break;
9572 case elfcpp::R_ARM_THM_PC12:
9573 reloc_status =
9574 Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
9576 break;
9578 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9579 reloc_status =
9580 Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
9581 0, thumb_bit);
9582 break;
9584 // These relocation truncate relocation results so we cannot handle them
9585 // in a relocatable link.
9586 case elfcpp::R_ARM_MOVT_ABS:
9587 case elfcpp::R_ARM_THM_MOVT_ABS:
9588 case elfcpp::R_ARM_MOVT_PREL:
9589 case elfcpp::R_ARM_MOVT_BREL:
9590 case elfcpp::R_ARM_THM_MOVT_PREL:
9591 case elfcpp::R_ARM_THM_MOVT_BREL:
9592 case elfcpp::R_ARM_ALU_PC_G0_NC:
9593 case elfcpp::R_ARM_ALU_PC_G0:
9594 case elfcpp::R_ARM_ALU_PC_G1_NC:
9595 case elfcpp::R_ARM_ALU_PC_G1:
9596 case elfcpp::R_ARM_ALU_PC_G2:
9597 case elfcpp::R_ARM_ALU_SB_G0_NC:
9598 case elfcpp::R_ARM_ALU_SB_G0:
9599 case elfcpp::R_ARM_ALU_SB_G1_NC:
9600 case elfcpp::R_ARM_ALU_SB_G1:
9601 case elfcpp::R_ARM_ALU_SB_G2:
9602 case elfcpp::R_ARM_LDR_PC_G0:
9603 case elfcpp::R_ARM_LDR_PC_G1:
9604 case elfcpp::R_ARM_LDR_PC_G2:
9605 case elfcpp::R_ARM_LDR_SB_G0:
9606 case elfcpp::R_ARM_LDR_SB_G1:
9607 case elfcpp::R_ARM_LDR_SB_G2:
9608 case elfcpp::R_ARM_LDRS_PC_G0:
9609 case elfcpp::R_ARM_LDRS_PC_G1:
9610 case elfcpp::R_ARM_LDRS_PC_G2:
9611 case elfcpp::R_ARM_LDRS_SB_G0:
9612 case elfcpp::R_ARM_LDRS_SB_G1:
9613 case elfcpp::R_ARM_LDRS_SB_G2:
9614 case elfcpp::R_ARM_LDC_PC_G0:
9615 case elfcpp::R_ARM_LDC_PC_G1:
9616 case elfcpp::R_ARM_LDC_PC_G2:
9617 case elfcpp::R_ARM_LDC_SB_G0:
9618 case elfcpp::R_ARM_LDC_SB_G1:
9619 case elfcpp::R_ARM_LDC_SB_G2:
9620 gold_error(_("cannot handle %s in a relocatable link"),
9621 arp->name().c_str());
9622 break;
9624 default:
9625 gold_unreachable();
9628 // Report any errors.
9629 switch (reloc_status)
9631 case Arm_relocate_functions<big_endian>::STATUS_OKAY:
9632 break;
9633 case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
9634 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9635 _("relocation overflow in %s"),
9636 arp->name().c_str());
9637 break;
9638 case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
9639 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9640 _("unexpected opcode while processing relocation %s"),
9641 arp->name().c_str());
9642 break;
9643 default:
9644 gold_unreachable();
9648 // Return the value to use for a dynamic symbol which requires special
9649 // treatment. This is how we support equality comparisons of function
9650 // pointers across shared library boundaries, as described in the
9651 // processor specific ABI supplement.
9653 template<bool big_endian>
9654 uint64_t
9655 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
9657 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
9658 return this->plt_section()->address() + gsym->plt_offset();
9661 // Map platform-specific relocs to real relocs
9663 template<bool big_endian>
9664 unsigned int
9665 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
9667 switch (r_type)
9669 case elfcpp::R_ARM_TARGET1:
9670 // This is either R_ARM_ABS32 or R_ARM_REL32;
9671 return elfcpp::R_ARM_ABS32;
9673 case elfcpp::R_ARM_TARGET2:
9674 // This can be any reloc type but ususally is R_ARM_GOT_PREL
9675 return elfcpp::R_ARM_GOT_PREL;
9677 default:
9678 return r_type;
9682 // Whether if two EABI versions V1 and V2 are compatible.
9684 template<bool big_endian>
9685 bool
9686 Target_arm<big_endian>::are_eabi_versions_compatible(
9687 elfcpp::Elf_Word v1,
9688 elfcpp::Elf_Word v2)
9690 // v4 and v5 are the same spec before and after it was released,
9691 // so allow mixing them.
9692 if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
9693 || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
9694 || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
9695 return true;
9697 return v1 == v2;
9700 // Combine FLAGS from an input object called NAME and the processor-specific
9701 // flags in the ELF header of the output. Much of this is adapted from the
9702 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
9703 // in bfd/elf32-arm.c.
9705 template<bool big_endian>
9706 void
9707 Target_arm<big_endian>::merge_processor_specific_flags(
9708 const std::string& name,
9709 elfcpp::Elf_Word flags)
9711 if (this->are_processor_specific_flags_set())
9713 elfcpp::Elf_Word out_flags = this->processor_specific_flags();
9715 // Nothing to merge if flags equal to those in output.
9716 if (flags == out_flags)
9717 return;
9719 // Complain about various flag mismatches.
9720 elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
9721 elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
9722 if (!this->are_eabi_versions_compatible(version1, version2)
9723 && parameters->options().warn_mismatch())
9724 gold_error(_("Source object %s has EABI version %d but output has "
9725 "EABI version %d."),
9726 name.c_str(),
9727 (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
9728 (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
9730 else
9732 // If the input is the default architecture and had the default
9733 // flags then do not bother setting the flags for the output
9734 // architecture, instead allow future merges to do this. If no
9735 // future merges ever set these flags then they will retain their
9736 // uninitialised values, which surprise surprise, correspond
9737 // to the default values.
9738 if (flags == 0)
9739 return;
9741 // This is the first time, just copy the flags.
9742 // We only copy the EABI version for now.
9743 this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
9747 // Adjust ELF file header.
9748 template<bool big_endian>
9749 void
9750 Target_arm<big_endian>::do_adjust_elf_header(
9751 unsigned char* view,
9752 int len) const
9754 gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
9756 elfcpp::Ehdr<32, big_endian> ehdr(view);
9757 unsigned char e_ident[elfcpp::EI_NIDENT];
9758 memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
9760 if (elfcpp::arm_eabi_version(this->processor_specific_flags())
9761 == elfcpp::EF_ARM_EABI_UNKNOWN)
9762 e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
9763 else
9764 e_ident[elfcpp::EI_OSABI] = 0;
9765 e_ident[elfcpp::EI_ABIVERSION] = 0;
9767 // FIXME: Do EF_ARM_BE8 adjustment.
9769 elfcpp::Ehdr_write<32, big_endian> oehdr(view);
9770 oehdr.put_e_ident(e_ident);
9773 // do_make_elf_object to override the same function in the base class.
9774 // We need to use a target-specific sub-class of Sized_relobj<32, big_endian>
9775 // to store ARM specific information. Hence we need to have our own
9776 // ELF object creation.
9778 template<bool big_endian>
9779 Object*
9780 Target_arm<big_endian>::do_make_elf_object(
9781 const std::string& name,
9782 Input_file* input_file,
9783 off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
9785 int et = ehdr.get_e_type();
9786 if (et == elfcpp::ET_REL)
9788 Arm_relobj<big_endian>* obj =
9789 new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
9790 obj->setup();
9791 return obj;
9793 else if (et == elfcpp::ET_DYN)
9795 Sized_dynobj<32, big_endian>* obj =
9796 new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
9797 obj->setup();
9798 return obj;
9800 else
9802 gold_error(_("%s: unsupported ELF file type %d"),
9803 name.c_str(), et);
9804 return NULL;
9808 // Read the architecture from the Tag_also_compatible_with attribute, if any.
9809 // Returns -1 if no architecture could be read.
9810 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
9812 template<bool big_endian>
9814 Target_arm<big_endian>::get_secondary_compatible_arch(
9815 const Attributes_section_data* pasd)
9817 const Object_attribute* known_attributes =
9818 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
9820 // Note: the tag and its argument below are uleb128 values, though
9821 // currently-defined values fit in one byte for each.
9822 const std::string& sv =
9823 known_attributes[elfcpp::Tag_also_compatible_with].string_value();
9824 if (sv.size() == 2
9825 && sv.data()[0] == elfcpp::Tag_CPU_arch
9826 && (sv.data()[1] & 128) != 128)
9827 return sv.data()[1];
9829 // This tag is "safely ignorable", so don't complain if it looks funny.
9830 return -1;
9833 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
9834 // The tag is removed if ARCH is -1.
9835 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
9837 template<bool big_endian>
9838 void
9839 Target_arm<big_endian>::set_secondary_compatible_arch(
9840 Attributes_section_data* pasd,
9841 int arch)
9843 Object_attribute* known_attributes =
9844 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
9846 if (arch == -1)
9848 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
9849 return;
9852 // Note: the tag and its argument below are uleb128 values, though
9853 // currently-defined values fit in one byte for each.
9854 char sv[3];
9855 sv[0] = elfcpp::Tag_CPU_arch;
9856 gold_assert(arch != 0);
9857 sv[1] = arch;
9858 sv[2] = '\0';
9860 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
9863 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
9864 // into account.
9865 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
9867 template<bool big_endian>
9869 Target_arm<big_endian>::tag_cpu_arch_combine(
9870 const char* name,
9871 int oldtag,
9872 int* secondary_compat_out,
9873 int newtag,
9874 int secondary_compat)
9876 #define T(X) elfcpp::TAG_CPU_ARCH_##X
9877 static const int v6t2[] =
9879 T(V6T2), // PRE_V4.
9880 T(V6T2), // V4.
9881 T(V6T2), // V4T.
9882 T(V6T2), // V5T.
9883 T(V6T2), // V5TE.
9884 T(V6T2), // V5TEJ.
9885 T(V6T2), // V6.
9886 T(V7), // V6KZ.
9887 T(V6T2) // V6T2.
9889 static const int v6k[] =
9891 T(V6K), // PRE_V4.
9892 T(V6K), // V4.
9893 T(V6K), // V4T.
9894 T(V6K), // V5T.
9895 T(V6K), // V5TE.
9896 T(V6K), // V5TEJ.
9897 T(V6K), // V6.
9898 T(V6KZ), // V6KZ.
9899 T(V7), // V6T2.
9900 T(V6K) // V6K.
9902 static const int v7[] =
9904 T(V7), // PRE_V4.
9905 T(V7), // V4.
9906 T(V7), // V4T.
9907 T(V7), // V5T.
9908 T(V7), // V5TE.
9909 T(V7), // V5TEJ.
9910 T(V7), // V6.
9911 T(V7), // V6KZ.
9912 T(V7), // V6T2.
9913 T(V7), // V6K.
9914 T(V7) // V7.
9916 static const int v6_m[] =
9918 -1, // PRE_V4.
9919 -1, // V4.
9920 T(V6K), // V4T.
9921 T(V6K), // V5T.
9922 T(V6K), // V5TE.
9923 T(V6K), // V5TEJ.
9924 T(V6K), // V6.
9925 T(V6KZ), // V6KZ.
9926 T(V7), // V6T2.
9927 T(V6K), // V6K.
9928 T(V7), // V7.
9929 T(V6_M) // V6_M.
9931 static const int v6s_m[] =
9933 -1, // PRE_V4.
9934 -1, // V4.
9935 T(V6K), // V4T.
9936 T(V6K), // V5T.
9937 T(V6K), // V5TE.
9938 T(V6K), // V5TEJ.
9939 T(V6K), // V6.
9940 T(V6KZ), // V6KZ.
9941 T(V7), // V6T2.
9942 T(V6K), // V6K.
9943 T(V7), // V7.
9944 T(V6S_M), // V6_M.
9945 T(V6S_M) // V6S_M.
9947 static const int v7e_m[] =
9949 -1, // PRE_V4.
9950 -1, // V4.
9951 T(V7E_M), // V4T.
9952 T(V7E_M), // V5T.
9953 T(V7E_M), // V5TE.
9954 T(V7E_M), // V5TEJ.
9955 T(V7E_M), // V6.
9956 T(V7E_M), // V6KZ.
9957 T(V7E_M), // V6T2.
9958 T(V7E_M), // V6K.
9959 T(V7E_M), // V7.
9960 T(V7E_M), // V6_M.
9961 T(V7E_M), // V6S_M.
9962 T(V7E_M) // V7E_M.
9964 static const int v4t_plus_v6_m[] =
9966 -1, // PRE_V4.
9967 -1, // V4.
9968 T(V4T), // V4T.
9969 T(V5T), // V5T.
9970 T(V5TE), // V5TE.
9971 T(V5TEJ), // V5TEJ.
9972 T(V6), // V6.
9973 T(V6KZ), // V6KZ.
9974 T(V6T2), // V6T2.
9975 T(V6K), // V6K.
9976 T(V7), // V7.
9977 T(V6_M), // V6_M.
9978 T(V6S_M), // V6S_M.
9979 T(V7E_M), // V7E_M.
9980 T(V4T_PLUS_V6_M) // V4T plus V6_M.
9982 static const int* comb[] =
9984 v6t2,
9985 v6k,
9987 v6_m,
9988 v6s_m,
9989 v7e_m,
9990 // Pseudo-architecture.
9991 v4t_plus_v6_m
9994 // Check we've not got a higher architecture than we know about.
9996 if (oldtag >= elfcpp::MAX_TAG_CPU_ARCH || newtag >= elfcpp::MAX_TAG_CPU_ARCH)
9998 gold_error(_("%s: unknown CPU architecture"), name);
9999 return -1;
10002 // Override old tag if we have a Tag_also_compatible_with on the output.
10004 if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10005 || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10006 oldtag = T(V4T_PLUS_V6_M);
10008 // And override the new tag if we have a Tag_also_compatible_with on the
10009 // input.
10011 if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10012 || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10013 newtag = T(V4T_PLUS_V6_M);
10015 // Architectures before V6KZ add features monotonically.
10016 int tagh = std::max(oldtag, newtag);
10017 if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10018 return tagh;
10020 int tagl = std::min(oldtag, newtag);
10021 int result = comb[tagh - T(V6T2)][tagl];
10023 // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10024 // as the canonical version.
10025 if (result == T(V4T_PLUS_V6_M))
10027 result = T(V4T);
10028 *secondary_compat_out = T(V6_M);
10030 else
10031 *secondary_compat_out = -1;
10033 if (result == -1)
10035 gold_error(_("%s: conflicting CPU architectures %d/%d"),
10036 name, oldtag, newtag);
10037 return -1;
10040 return result;
10041 #undef T
10044 // Helper to print AEABI enum tag value.
10046 template<bool big_endian>
10047 std::string
10048 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10050 static const char* aeabi_enum_names[] =
10051 { "", "variable-size", "32-bit", "" };
10052 const size_t aeabi_enum_names_size =
10053 sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10055 if (value < aeabi_enum_names_size)
10056 return std::string(aeabi_enum_names[value]);
10057 else
10059 char buffer[100];
10060 sprintf(buffer, "<unknown value %u>", value);
10061 return std::string(buffer);
10065 // Return the string value to store in TAG_CPU_name.
10067 template<bool big_endian>
10068 std::string
10069 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10071 static const char* name_table[] = {
10072 // These aren't real CPU names, but we can't guess
10073 // that from the architecture version alone.
10074 "Pre v4",
10075 "ARM v4",
10076 "ARM v4T",
10077 "ARM v5T",
10078 "ARM v5TE",
10079 "ARM v5TEJ",
10080 "ARM v6",
10081 "ARM v6KZ",
10082 "ARM v6T2",
10083 "ARM v6K",
10084 "ARM v7",
10085 "ARM v6-M",
10086 "ARM v6S-M",
10087 "ARM v7E-M"
10089 const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10091 if (value < name_table_size)
10092 return std::string(name_table[value]);
10093 else
10095 char buffer[100];
10096 sprintf(buffer, "<unknown CPU value %u>", value);
10097 return std::string(buffer);
10101 // Merge object attributes from input file called NAME with those of the
10102 // output. The input object attributes are in the object pointed by PASD.
10104 template<bool big_endian>
10105 void
10106 Target_arm<big_endian>::merge_object_attributes(
10107 const char* name,
10108 const Attributes_section_data* pasd)
10110 // Return if there is no attributes section data.
10111 if (pasd == NULL)
10112 return;
10114 // If output has no object attributes, just copy.
10115 const int vendor = Object_attribute::OBJ_ATTR_PROC;
10116 if (this->attributes_section_data_ == NULL)
10118 this->attributes_section_data_ = new Attributes_section_data(*pasd);
10119 Object_attribute* out_attr =
10120 this->attributes_section_data_->known_attributes(vendor);
10122 // We do not output objects with Tag_MPextension_use_legacy - we move
10123 // the attribute's value to Tag_MPextension_use. */
10124 if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10126 if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10127 && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10128 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10130 gold_error(_("%s has both the current and legacy "
10131 "Tag_MPextension_use attributes"),
10132 name);
10135 out_attr[elfcpp::Tag_MPextension_use] =
10136 out_attr[elfcpp::Tag_MPextension_use_legacy];
10137 out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10138 out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10141 return;
10144 const Object_attribute* in_attr = pasd->known_attributes(vendor);
10145 Object_attribute* out_attr =
10146 this->attributes_section_data_->known_attributes(vendor);
10148 // This needs to happen before Tag_ABI_FP_number_model is merged. */
10149 if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10150 != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
10152 // Ignore mismatches if the object doesn't use floating point. */
10153 if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
10154 out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10155 in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10156 else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
10157 && parameters->options().warn_mismatch())
10158 gold_error(_("%s uses VFP register arguments, output does not"),
10159 name);
10162 for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10164 // Merge this attribute with existing attributes.
10165 switch (i)
10167 case elfcpp::Tag_CPU_raw_name:
10168 case elfcpp::Tag_CPU_name:
10169 // These are merged after Tag_CPU_arch.
10170 break;
10172 case elfcpp::Tag_ABI_optimization_goals:
10173 case elfcpp::Tag_ABI_FP_optimization_goals:
10174 // Use the first value seen.
10175 break;
10177 case elfcpp::Tag_CPU_arch:
10179 unsigned int saved_out_attr = out_attr->int_value();
10180 // Merge Tag_CPU_arch and Tag_also_compatible_with.
10181 int secondary_compat =
10182 this->get_secondary_compatible_arch(pasd);
10183 int secondary_compat_out =
10184 this->get_secondary_compatible_arch(
10185 this->attributes_section_data_);
10186 out_attr[i].set_int_value(
10187 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10188 &secondary_compat_out,
10189 in_attr[i].int_value(),
10190 secondary_compat));
10191 this->set_secondary_compatible_arch(this->attributes_section_data_,
10192 secondary_compat_out);
10194 // Merge Tag_CPU_name and Tag_CPU_raw_name.
10195 if (out_attr[i].int_value() == saved_out_attr)
10196 ; // Leave the names alone.
10197 else if (out_attr[i].int_value() == in_attr[i].int_value())
10199 // The output architecture has been changed to match the
10200 // input architecture. Use the input names.
10201 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10202 in_attr[elfcpp::Tag_CPU_name].string_value());
10203 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10204 in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10206 else
10208 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10209 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10212 // If we still don't have a value for Tag_CPU_name,
10213 // make one up now. Tag_CPU_raw_name remains blank.
10214 if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10216 const std::string cpu_name =
10217 this->tag_cpu_name_value(out_attr[i].int_value());
10218 // FIXME: If we see an unknown CPU, this will be set
10219 // to "<unknown CPU n>", where n is the attribute value.
10220 // This is different from BFD, which leaves the name alone.
10221 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10224 break;
10226 case elfcpp::Tag_ARM_ISA_use:
10227 case elfcpp::Tag_THUMB_ISA_use:
10228 case elfcpp::Tag_WMMX_arch:
10229 case elfcpp::Tag_Advanced_SIMD_arch:
10230 // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10231 case elfcpp::Tag_ABI_FP_rounding:
10232 case elfcpp::Tag_ABI_FP_exceptions:
10233 case elfcpp::Tag_ABI_FP_user_exceptions:
10234 case elfcpp::Tag_ABI_FP_number_model:
10235 case elfcpp::Tag_VFP_HP_extension:
10236 case elfcpp::Tag_CPU_unaligned_access:
10237 case elfcpp::Tag_T2EE_use:
10238 case elfcpp::Tag_Virtualization_use:
10239 case elfcpp::Tag_MPextension_use:
10240 // Use the largest value specified.
10241 if (in_attr[i].int_value() > out_attr[i].int_value())
10242 out_attr[i].set_int_value(in_attr[i].int_value());
10243 break;
10245 case elfcpp::Tag_ABI_align8_preserved:
10246 case elfcpp::Tag_ABI_PCS_RO_data:
10247 // Use the smallest value specified.
10248 if (in_attr[i].int_value() < out_attr[i].int_value())
10249 out_attr[i].set_int_value(in_attr[i].int_value());
10250 break;
10252 case elfcpp::Tag_ABI_align8_needed:
10253 if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10254 && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10255 || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10256 == 0)))
10258 // This error message should be enabled once all non-conformant
10259 // binaries in the toolchain have had the attributes set
10260 // properly.
10261 // gold_error(_("output 8-byte data alignment conflicts with %s"),
10262 // name);
10264 // Fall through.
10265 case elfcpp::Tag_ABI_FP_denormal:
10266 case elfcpp::Tag_ABI_PCS_GOT_use:
10268 // These tags have 0 = don't care, 1 = strong requirement,
10269 // 2 = weak requirement.
10270 static const int order_021[3] = {0, 2, 1};
10272 // Use the "greatest" from the sequence 0, 2, 1, or the largest
10273 // value if greater than 2 (for future-proofing).
10274 if ((in_attr[i].int_value() > 2
10275 && in_attr[i].int_value() > out_attr[i].int_value())
10276 || (in_attr[i].int_value() <= 2
10277 && out_attr[i].int_value() <= 2
10278 && (order_021[in_attr[i].int_value()]
10279 > order_021[out_attr[i].int_value()])))
10280 out_attr[i].set_int_value(in_attr[i].int_value());
10282 break;
10284 case elfcpp::Tag_CPU_arch_profile:
10285 if (out_attr[i].int_value() != in_attr[i].int_value())
10287 // 0 will merge with anything.
10288 // 'A' and 'S' merge to 'A'.
10289 // 'R' and 'S' merge to 'R'.
10290 // 'M' and 'A|R|S' is an error.
10291 if (out_attr[i].int_value() == 0
10292 || (out_attr[i].int_value() == 'S'
10293 && (in_attr[i].int_value() == 'A'
10294 || in_attr[i].int_value() == 'R')))
10295 out_attr[i].set_int_value(in_attr[i].int_value());
10296 else if (in_attr[i].int_value() == 0
10297 || (in_attr[i].int_value() == 'S'
10298 && (out_attr[i].int_value() == 'A'
10299 || out_attr[i].int_value() == 'R')))
10300 ; // Do nothing.
10301 else if (parameters->options().warn_mismatch())
10303 gold_error
10304 (_("conflicting architecture profiles %c/%c"),
10305 in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10306 out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10309 break;
10310 case elfcpp::Tag_VFP_arch:
10312 static const struct
10314 int ver;
10315 int regs;
10316 } vfp_versions[7] =
10318 {0, 0},
10319 {1, 16},
10320 {2, 16},
10321 {3, 32},
10322 {3, 16},
10323 {4, 32},
10324 {4, 16}
10327 // Values greater than 6 aren't defined, so just pick the
10328 // biggest.
10329 if (in_attr[i].int_value() > 6
10330 && in_attr[i].int_value() > out_attr[i].int_value())
10332 *out_attr = *in_attr;
10333 break;
10335 // The output uses the superset of input features
10336 // (ISA version) and registers.
10337 int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10338 vfp_versions[out_attr[i].int_value()].ver);
10339 int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10340 vfp_versions[out_attr[i].int_value()].regs);
10341 // This assumes all possible supersets are also a valid
10342 // options.
10343 int newval;
10344 for (newval = 6; newval > 0; newval--)
10346 if (regs == vfp_versions[newval].regs
10347 && ver == vfp_versions[newval].ver)
10348 break;
10350 out_attr[i].set_int_value(newval);
10352 break;
10353 case elfcpp::Tag_PCS_config:
10354 if (out_attr[i].int_value() == 0)
10355 out_attr[i].set_int_value(in_attr[i].int_value());
10356 else if (in_attr[i].int_value() != 0
10357 && out_attr[i].int_value() != 0
10358 && parameters->options().warn_mismatch())
10360 // It's sometimes ok to mix different configs, so this is only
10361 // a warning.
10362 gold_warning(_("%s: conflicting platform configuration"), name);
10364 break;
10365 case elfcpp::Tag_ABI_PCS_R9_use:
10366 if (in_attr[i].int_value() != out_attr[i].int_value()
10367 && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10368 && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10369 && parameters->options().warn_mismatch())
10371 gold_error(_("%s: conflicting use of R9"), name);
10373 if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10374 out_attr[i].set_int_value(in_attr[i].int_value());
10375 break;
10376 case elfcpp::Tag_ABI_PCS_RW_data:
10377 if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10378 && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10379 != elfcpp::AEABI_R9_SB)
10380 && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10381 != elfcpp::AEABI_R9_unused)
10382 && parameters->options().warn_mismatch())
10384 gold_error(_("%s: SB relative addressing conflicts with use "
10385 "of R9"),
10386 name);
10388 // Use the smallest value specified.
10389 if (in_attr[i].int_value() < out_attr[i].int_value())
10390 out_attr[i].set_int_value(in_attr[i].int_value());
10391 break;
10392 case elfcpp::Tag_ABI_PCS_wchar_t:
10393 if (out_attr[i].int_value()
10394 && in_attr[i].int_value()
10395 && out_attr[i].int_value() != in_attr[i].int_value()
10396 && parameters->options().warn_mismatch()
10397 && parameters->options().wchar_size_warning())
10399 gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10400 "use %u-byte wchar_t; use of wchar_t values "
10401 "across objects may fail"),
10402 name, in_attr[i].int_value(),
10403 out_attr[i].int_value());
10405 else if (in_attr[i].int_value() && !out_attr[i].int_value())
10406 out_attr[i].set_int_value(in_attr[i].int_value());
10407 break;
10408 case elfcpp::Tag_ABI_enum_size:
10409 if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10411 if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10412 || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10414 // The existing object is compatible with anything.
10415 // Use whatever requirements the new object has.
10416 out_attr[i].set_int_value(in_attr[i].int_value());
10418 else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10419 && out_attr[i].int_value() != in_attr[i].int_value()
10420 && parameters->options().warn_mismatch()
10421 && parameters->options().enum_size_warning())
10423 unsigned int in_value = in_attr[i].int_value();
10424 unsigned int out_value = out_attr[i].int_value();
10425 gold_warning(_("%s uses %s enums yet the output is to use "
10426 "%s enums; use of enum values across objects "
10427 "may fail"),
10428 name,
10429 this->aeabi_enum_name(in_value).c_str(),
10430 this->aeabi_enum_name(out_value).c_str());
10433 break;
10434 case elfcpp::Tag_ABI_VFP_args:
10435 // Aready done.
10436 break;
10437 case elfcpp::Tag_ABI_WMMX_args:
10438 if (in_attr[i].int_value() != out_attr[i].int_value()
10439 && parameters->options().warn_mismatch())
10441 gold_error(_("%s uses iWMMXt register arguments, output does "
10442 "not"),
10443 name);
10445 break;
10446 case Object_attribute::Tag_compatibility:
10447 // Merged in target-independent code.
10448 break;
10449 case elfcpp::Tag_ABI_HardFP_use:
10450 // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10451 if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10452 || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10453 out_attr[i].set_int_value(3);
10454 else if (in_attr[i].int_value() > out_attr[i].int_value())
10455 out_attr[i].set_int_value(in_attr[i].int_value());
10456 break;
10457 case elfcpp::Tag_ABI_FP_16bit_format:
10458 if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10460 if (in_attr[i].int_value() != out_attr[i].int_value()
10461 && parameters->options().warn_mismatch())
10462 gold_error(_("fp16 format mismatch between %s and output"),
10463 name);
10465 if (in_attr[i].int_value() != 0)
10466 out_attr[i].set_int_value(in_attr[i].int_value());
10467 break;
10469 case elfcpp::Tag_DIV_use:
10470 // This tag is set to zero if we can use UDIV and SDIV in Thumb
10471 // mode on a v7-M or v7-R CPU; to one if we can not use UDIV or
10472 // SDIV at all; and to two if we can use UDIV or SDIV on a v7-A
10473 // CPU. We will merge as follows: If the input attribute's value
10474 // is one then the output attribute's value remains unchanged. If
10475 // the input attribute's value is zero or two then if the output
10476 // attribute's value is one the output value is set to the input
10477 // value, otherwise the output value must be the same as the
10478 // inputs. */
10479 if (in_attr[i].int_value() != 1 && out_attr[i].int_value() != 1)
10481 if (in_attr[i].int_value() != out_attr[i].int_value())
10483 gold_error(_("DIV usage mismatch between %s and output"),
10484 name);
10488 if (in_attr[i].int_value() != 1)
10489 out_attr[i].set_int_value(in_attr[i].int_value());
10491 break;
10493 case elfcpp::Tag_MPextension_use_legacy:
10494 // We don't output objects with Tag_MPextension_use_legacy - we
10495 // move the value to Tag_MPextension_use.
10496 if (in_attr[i].int_value() != 0
10497 && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10499 if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10500 != in_attr[i].int_value())
10502 gold_error(_("%s has has both the current and legacy "
10503 "Tag_MPextension_use attributes"),
10504 name);
10508 if (in_attr[i].int_value()
10509 > out_attr[elfcpp::Tag_MPextension_use].int_value())
10510 out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10512 break;
10514 case elfcpp::Tag_nodefaults:
10515 // This tag is set if it exists, but the value is unused (and is
10516 // typically zero). We don't actually need to do anything here -
10517 // the merge happens automatically when the type flags are merged
10518 // below.
10519 break;
10520 case elfcpp::Tag_also_compatible_with:
10521 // Already done in Tag_CPU_arch.
10522 break;
10523 case elfcpp::Tag_conformance:
10524 // Keep the attribute if it matches. Throw it away otherwise.
10525 // No attribute means no claim to conform.
10526 if (in_attr[i].string_value() != out_attr[i].string_value())
10527 out_attr[i].set_string_value("");
10528 break;
10530 default:
10532 const char* err_object = NULL;
10534 // The "known_obj_attributes" table does contain some undefined
10535 // attributes. Ensure that there are unused.
10536 if (out_attr[i].int_value() != 0
10537 || out_attr[i].string_value() != "")
10538 err_object = "output";
10539 else if (in_attr[i].int_value() != 0
10540 || in_attr[i].string_value() != "")
10541 err_object = name;
10543 if (err_object != NULL
10544 && parameters->options().warn_mismatch())
10546 // Attribute numbers >=64 (mod 128) can be safely ignored.
10547 if ((i & 127) < 64)
10548 gold_error(_("%s: unknown mandatory EABI object attribute "
10549 "%d"),
10550 err_object, i);
10551 else
10552 gold_warning(_("%s: unknown EABI object attribute %d"),
10553 err_object, i);
10556 // Only pass on attributes that match in both inputs.
10557 if (!in_attr[i].matches(out_attr[i]))
10559 out_attr[i].set_int_value(0);
10560 out_attr[i].set_string_value("");
10565 // If out_attr was copied from in_attr then it won't have a type yet.
10566 if (in_attr[i].type() && !out_attr[i].type())
10567 out_attr[i].set_type(in_attr[i].type());
10570 // Merge Tag_compatibility attributes and any common GNU ones.
10571 this->attributes_section_data_->merge(name, pasd);
10573 // Check for any attributes not known on ARM.
10574 typedef Vendor_object_attributes::Other_attributes Other_attributes;
10575 const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10576 Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10577 Other_attributes* out_other_attributes =
10578 this->attributes_section_data_->other_attributes(vendor);
10579 Other_attributes::iterator out_iter = out_other_attributes->begin();
10581 while (in_iter != in_other_attributes->end()
10582 || out_iter != out_other_attributes->end())
10584 const char* err_object = NULL;
10585 int err_tag = 0;
10587 // The tags for each list are in numerical order.
10588 // If the tags are equal, then merge.
10589 if (out_iter != out_other_attributes->end()
10590 && (in_iter == in_other_attributes->end()
10591 || in_iter->first > out_iter->first))
10593 // This attribute only exists in output. We can't merge, and we
10594 // don't know what the tag means, so delete it.
10595 err_object = "output";
10596 err_tag = out_iter->first;
10597 int saved_tag = out_iter->first;
10598 delete out_iter->second;
10599 out_other_attributes->erase(out_iter);
10600 out_iter = out_other_attributes->upper_bound(saved_tag);
10602 else if (in_iter != in_other_attributes->end()
10603 && (out_iter != out_other_attributes->end()
10604 || in_iter->first < out_iter->first))
10606 // This attribute only exists in input. We can't merge, and we
10607 // don't know what the tag means, so ignore it.
10608 err_object = name;
10609 err_tag = in_iter->first;
10610 ++in_iter;
10612 else // The tags are equal.
10614 // As present, all attributes in the list are unknown, and
10615 // therefore can't be merged meaningfully.
10616 err_object = "output";
10617 err_tag = out_iter->first;
10619 // Only pass on attributes that match in both inputs.
10620 if (!in_iter->second->matches(*(out_iter->second)))
10622 // No match. Delete the attribute.
10623 int saved_tag = out_iter->first;
10624 delete out_iter->second;
10625 out_other_attributes->erase(out_iter);
10626 out_iter = out_other_attributes->upper_bound(saved_tag);
10628 else
10630 // Matched. Keep the attribute and move to the next.
10631 ++out_iter;
10632 ++in_iter;
10636 if (err_object && parameters->options().warn_mismatch())
10638 // Attribute numbers >=64 (mod 128) can be safely ignored. */
10639 if ((err_tag & 127) < 64)
10641 gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10642 err_object, err_tag);
10644 else
10646 gold_warning(_("%s: unknown EABI object attribute %d"),
10647 err_object, err_tag);
10653 // Stub-generation methods for Target_arm.
10655 // Make a new Arm_input_section object.
10657 template<bool big_endian>
10658 Arm_input_section<big_endian>*
10659 Target_arm<big_endian>::new_arm_input_section(
10660 Relobj* relobj,
10661 unsigned int shndx)
10663 Section_id sid(relobj, shndx);
10665 Arm_input_section<big_endian>* arm_input_section =
10666 new Arm_input_section<big_endian>(relobj, shndx);
10667 arm_input_section->init();
10669 // Register new Arm_input_section in map for look-up.
10670 std::pair<typename Arm_input_section_map::iterator, bool> ins =
10671 this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
10673 // Make sure that it we have not created another Arm_input_section
10674 // for this input section already.
10675 gold_assert(ins.second);
10677 return arm_input_section;
10680 // Find the Arm_input_section object corresponding to the SHNDX-th input
10681 // section of RELOBJ.
10683 template<bool big_endian>
10684 Arm_input_section<big_endian>*
10685 Target_arm<big_endian>::find_arm_input_section(
10686 Relobj* relobj,
10687 unsigned int shndx) const
10689 Section_id sid(relobj, shndx);
10690 typename Arm_input_section_map::const_iterator p =
10691 this->arm_input_section_map_.find(sid);
10692 return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
10695 // Make a new stub table.
10697 template<bool big_endian>
10698 Stub_table<big_endian>*
10699 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
10701 Stub_table<big_endian>* stub_table =
10702 new Stub_table<big_endian>(owner);
10703 this->stub_tables_.push_back(stub_table);
10705 stub_table->set_address(owner->address() + owner->data_size());
10706 stub_table->set_file_offset(owner->offset() + owner->data_size());
10707 stub_table->finalize_data_size();
10709 return stub_table;
10712 // Scan a relocation for stub generation.
10714 template<bool big_endian>
10715 void
10716 Target_arm<big_endian>::scan_reloc_for_stub(
10717 const Relocate_info<32, big_endian>* relinfo,
10718 unsigned int r_type,
10719 const Sized_symbol<32>* gsym,
10720 unsigned int r_sym,
10721 const Symbol_value<32>* psymval,
10722 elfcpp::Elf_types<32>::Elf_Swxword addend,
10723 Arm_address address)
10725 typedef typename Target_arm<big_endian>::Relocate Relocate;
10727 const Arm_relobj<big_endian>* arm_relobj =
10728 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10730 bool target_is_thumb;
10731 Symbol_value<32> symval;
10732 if (gsym != NULL)
10734 // This is a global symbol. Determine if we use PLT and if the
10735 // final target is THUMB.
10736 if (gsym->use_plt_offset(Relocate::reloc_is_non_pic(r_type)))
10738 // This uses a PLT, change the symbol value.
10739 symval.set_output_value(this->plt_section()->address()
10740 + gsym->plt_offset());
10741 psymval = &symval;
10742 target_is_thumb = false;
10744 else if (gsym->is_undefined())
10745 // There is no need to generate a stub symbol is undefined.
10746 return;
10747 else
10749 target_is_thumb =
10750 ((gsym->type() == elfcpp::STT_ARM_TFUNC)
10751 || (gsym->type() == elfcpp::STT_FUNC
10752 && !gsym->is_undefined()
10753 && ((psymval->value(arm_relobj, 0) & 1) != 0)));
10756 else
10758 // This is a local symbol. Determine if the final target is THUMB.
10759 target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
10762 // Strip LSB if this points to a THUMB target.
10763 const Arm_reloc_property* reloc_property =
10764 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10765 gold_assert(reloc_property != NULL);
10766 if (target_is_thumb
10767 && reloc_property->uses_thumb_bit()
10768 && ((psymval->value(arm_relobj, 0) & 1) != 0))
10770 Arm_address stripped_value =
10771 psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
10772 symval.set_output_value(stripped_value);
10773 psymval = &symval;
10776 // Get the symbol value.
10777 Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
10779 // Owing to pipelining, the PC relative branches below actually skip
10780 // two instructions when the branch offset is 0.
10781 Arm_address destination;
10782 switch (r_type)
10784 case elfcpp::R_ARM_CALL:
10785 case elfcpp::R_ARM_JUMP24:
10786 case elfcpp::R_ARM_PLT32:
10787 // ARM branches.
10788 destination = value + addend + 8;
10789 break;
10790 case elfcpp::R_ARM_THM_CALL:
10791 case elfcpp::R_ARM_THM_XPC22:
10792 case elfcpp::R_ARM_THM_JUMP24:
10793 case elfcpp::R_ARM_THM_JUMP19:
10794 // THUMB branches.
10795 destination = value + addend + 4;
10796 break;
10797 default:
10798 gold_unreachable();
10801 Reloc_stub* stub = NULL;
10802 Stub_type stub_type =
10803 Reloc_stub::stub_type_for_reloc(r_type, address, destination,
10804 target_is_thumb);
10805 if (stub_type != arm_stub_none)
10807 // Try looking up an existing stub from a stub table.
10808 Stub_table<big_endian>* stub_table =
10809 arm_relobj->stub_table(relinfo->data_shndx);
10810 gold_assert(stub_table != NULL);
10812 // Locate stub by destination.
10813 Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
10815 // Create a stub if there is not one already
10816 stub = stub_table->find_reloc_stub(stub_key);
10817 if (stub == NULL)
10819 // create a new stub and add it to stub table.
10820 stub = this->stub_factory().make_reloc_stub(stub_type);
10821 stub_table->add_reloc_stub(stub, stub_key);
10824 // Record the destination address.
10825 stub->set_destination_address(destination
10826 | (target_is_thumb ? 1 : 0));
10829 // For Cortex-A8, we need to record a relocation at 4K page boundary.
10830 if (this->fix_cortex_a8_
10831 && (r_type == elfcpp::R_ARM_THM_JUMP24
10832 || r_type == elfcpp::R_ARM_THM_JUMP19
10833 || r_type == elfcpp::R_ARM_THM_CALL
10834 || r_type == elfcpp::R_ARM_THM_XPC22)
10835 && (address & 0xfffU) == 0xffeU)
10837 // Found a candidate. Note we haven't checked the destination is
10838 // within 4K here: if we do so (and don't create a record) we can't
10839 // tell that a branch should have been relocated when scanning later.
10840 this->cortex_a8_relocs_info_[address] =
10841 new Cortex_a8_reloc(stub, r_type,
10842 destination | (target_is_thumb ? 1 : 0));
10846 // This function scans a relocation sections for stub generation.
10847 // The template parameter Relocate must be a class type which provides
10848 // a single function, relocate(), which implements the machine
10849 // specific part of a relocation.
10851 // BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type:
10852 // SHT_REL or SHT_RELA.
10854 // PRELOCS points to the relocation data. RELOC_COUNT is the number
10855 // of relocs. OUTPUT_SECTION is the output section.
10856 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
10857 // mapped to output offsets.
10859 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
10860 // VIEW_SIZE is the size. These refer to the input section, unless
10861 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
10862 // the output section.
10864 template<bool big_endian>
10865 template<int sh_type>
10866 void inline
10867 Target_arm<big_endian>::scan_reloc_section_for_stubs(
10868 const Relocate_info<32, big_endian>* relinfo,
10869 const unsigned char* prelocs,
10870 size_t reloc_count,
10871 Output_section* output_section,
10872 bool needs_special_offset_handling,
10873 const unsigned char* view,
10874 elfcpp::Elf_types<32>::Elf_Addr view_address,
10875 section_size_type)
10877 typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
10878 const int reloc_size =
10879 Reloc_types<sh_type, 32, big_endian>::reloc_size;
10881 Arm_relobj<big_endian>* arm_object =
10882 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10883 unsigned int local_count = arm_object->local_symbol_count();
10885 Comdat_behavior comdat_behavior = CB_UNDETERMINED;
10887 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
10889 Reltype reloc(prelocs);
10891 typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
10892 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
10893 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
10895 r_type = this->get_real_reloc_type(r_type);
10897 // Only a few relocation types need stubs.
10898 if ((r_type != elfcpp::R_ARM_CALL)
10899 && (r_type != elfcpp::R_ARM_JUMP24)
10900 && (r_type != elfcpp::R_ARM_PLT32)
10901 && (r_type != elfcpp::R_ARM_THM_CALL)
10902 && (r_type != elfcpp::R_ARM_THM_XPC22)
10903 && (r_type != elfcpp::R_ARM_THM_JUMP24)
10904 && (r_type != elfcpp::R_ARM_THM_JUMP19)
10905 && (r_type != elfcpp::R_ARM_V4BX))
10906 continue;
10908 section_offset_type offset =
10909 convert_to_section_size_type(reloc.get_r_offset());
10911 if (needs_special_offset_handling)
10913 offset = output_section->output_offset(relinfo->object,
10914 relinfo->data_shndx,
10915 offset);
10916 if (offset == -1)
10917 continue;
10920 // Create a v4bx stub if --fix-v4bx-interworking is used.
10921 if (r_type == elfcpp::R_ARM_V4BX)
10923 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
10925 // Get the BX instruction.
10926 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
10927 const Valtype* wv =
10928 reinterpret_cast<const Valtype*>(view + offset);
10929 elfcpp::Elf_types<32>::Elf_Swxword insn =
10930 elfcpp::Swap<32, big_endian>::readval(wv);
10931 const uint32_t reg = (insn & 0xf);
10933 if (reg < 0xf)
10935 // Try looking up an existing stub from a stub table.
10936 Stub_table<big_endian>* stub_table =
10937 arm_object->stub_table(relinfo->data_shndx);
10938 gold_assert(stub_table != NULL);
10940 if (stub_table->find_arm_v4bx_stub(reg) == NULL)
10942 // create a new stub and add it to stub table.
10943 Arm_v4bx_stub* stub =
10944 this->stub_factory().make_arm_v4bx_stub(reg);
10945 gold_assert(stub != NULL);
10946 stub_table->add_arm_v4bx_stub(stub);
10950 continue;
10953 // Get the addend.
10954 Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
10955 elfcpp::Elf_types<32>::Elf_Swxword addend =
10956 stub_addend_reader(r_type, view + offset, reloc);
10958 const Sized_symbol<32>* sym;
10960 Symbol_value<32> symval;
10961 const Symbol_value<32> *psymval;
10962 bool is_defined_in_discarded_section;
10963 unsigned int shndx;
10964 if (r_sym < local_count)
10966 sym = NULL;
10967 psymval = arm_object->local_symbol(r_sym);
10969 // If the local symbol belongs to a section we are discarding,
10970 // and that section is a debug section, try to find the
10971 // corresponding kept section and map this symbol to its
10972 // counterpart in the kept section. The symbol must not
10973 // correspond to a section we are folding.
10974 bool is_ordinary;
10975 shndx = psymval->input_shndx(&is_ordinary);
10976 is_defined_in_discarded_section =
10977 (is_ordinary
10978 && shndx != elfcpp::SHN_UNDEF
10979 && !arm_object->is_section_included(shndx)
10980 && !relinfo->symtab->is_section_folded(arm_object, shndx));
10982 // We need to compute the would-be final value of this local
10983 // symbol.
10984 if (!is_defined_in_discarded_section)
10986 typedef Sized_relobj<32, big_endian> ObjType;
10987 typename ObjType::Compute_final_local_value_status status =
10988 arm_object->compute_final_local_value(r_sym, psymval, &symval,
10989 relinfo->symtab);
10990 if (status == ObjType::CFLV_OK)
10992 // Currently we cannot handle a branch to a target in
10993 // a merged section. If this is the case, issue an error
10994 // and also free the merge symbol value.
10995 if (!symval.has_output_value())
10997 const std::string& section_name =
10998 arm_object->section_name(shndx);
10999 arm_object->error(_("cannot handle branch to local %u "
11000 "in a merged section %s"),
11001 r_sym, section_name.c_str());
11003 psymval = &symval;
11005 else
11007 // We cannot determine the final value.
11008 continue;
11012 else
11014 const Symbol* gsym;
11015 gsym = arm_object->global_symbol(r_sym);
11016 gold_assert(gsym != NULL);
11017 if (gsym->is_forwarder())
11018 gsym = relinfo->symtab->resolve_forwards(gsym);
11020 sym = static_cast<const Sized_symbol<32>*>(gsym);
11021 if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11022 symval.set_output_symtab_index(sym->symtab_index());
11023 else
11024 symval.set_no_output_symtab_entry();
11026 // We need to compute the would-be final value of this global
11027 // symbol.
11028 const Symbol_table* symtab = relinfo->symtab;
11029 const Sized_symbol<32>* sized_symbol =
11030 symtab->get_sized_symbol<32>(gsym);
11031 Symbol_table::Compute_final_value_status status;
11032 Arm_address value =
11033 symtab->compute_final_value<32>(sized_symbol, &status);
11035 // Skip this if the symbol has not output section.
11036 if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11037 continue;
11038 symval.set_output_value(value);
11040 if (gsym->type() == elfcpp::STT_TLS)
11041 symval.set_is_tls_symbol();
11042 else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11043 symval.set_is_ifunc_symbol();
11044 psymval = &symval;
11046 is_defined_in_discarded_section =
11047 (gsym->is_defined_in_discarded_section()
11048 && gsym->is_undefined());
11049 shndx = 0;
11052 Symbol_value<32> symval2;
11053 if (is_defined_in_discarded_section)
11055 if (comdat_behavior == CB_UNDETERMINED)
11057 std::string name = arm_object->section_name(relinfo->data_shndx);
11058 comdat_behavior = get_comdat_behavior(name.c_str());
11060 if (comdat_behavior == CB_PRETEND)
11062 // FIXME: This case does not work for global symbols.
11063 // We have no place to store the original section index.
11064 // Fortunately this does not matter for comdat sections,
11065 // only for sections explicitly discarded by a linker
11066 // script.
11067 bool found;
11068 typename elfcpp::Elf_types<32>::Elf_Addr value =
11069 arm_object->map_to_kept_section(shndx, &found);
11070 if (found)
11071 symval2.set_output_value(value + psymval->input_value());
11072 else
11073 symval2.set_output_value(0);
11075 else
11077 if (comdat_behavior == CB_WARNING)
11078 gold_warning_at_location(relinfo, i, offset,
11079 _("relocation refers to discarded "
11080 "section"));
11081 symval2.set_output_value(0);
11083 symval2.set_no_output_symtab_entry();
11084 psymval = &symval2;
11087 // If symbol is a section symbol, we don't know the actual type of
11088 // destination. Give up.
11089 if (psymval->is_section_symbol())
11090 continue;
11092 this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11093 addend, view_address + offset);
11097 // Scan an input section for stub generation.
11099 template<bool big_endian>
11100 void
11101 Target_arm<big_endian>::scan_section_for_stubs(
11102 const Relocate_info<32, big_endian>* relinfo,
11103 unsigned int sh_type,
11104 const unsigned char* prelocs,
11105 size_t reloc_count,
11106 Output_section* output_section,
11107 bool needs_special_offset_handling,
11108 const unsigned char* view,
11109 Arm_address view_address,
11110 section_size_type view_size)
11112 if (sh_type == elfcpp::SHT_REL)
11113 this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11114 relinfo,
11115 prelocs,
11116 reloc_count,
11117 output_section,
11118 needs_special_offset_handling,
11119 view,
11120 view_address,
11121 view_size);
11122 else if (sh_type == elfcpp::SHT_RELA)
11123 // We do not support RELA type relocations yet. This is provided for
11124 // completeness.
11125 this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11126 relinfo,
11127 prelocs,
11128 reloc_count,
11129 output_section,
11130 needs_special_offset_handling,
11131 view,
11132 view_address,
11133 view_size);
11134 else
11135 gold_unreachable();
11138 // Group input sections for stub generation.
11140 // We goup input sections in an output sections so that the total size,
11141 // including any padding space due to alignment is smaller than GROUP_SIZE
11142 // unless the only input section in group is bigger than GROUP_SIZE already.
11143 // Then an ARM stub table is created to follow the last input section
11144 // in group. For each group an ARM stub table is created an is placed
11145 // after the last group. If STUB_ALWATS_AFTER_BRANCH is false, we further
11146 // extend the group after the stub table.
11148 template<bool big_endian>
11149 void
11150 Target_arm<big_endian>::group_sections(
11151 Layout* layout,
11152 section_size_type group_size,
11153 bool stubs_always_after_branch)
11155 // Group input sections and insert stub table
11156 Layout::Section_list section_list;
11157 layout->get_allocated_sections(&section_list);
11158 for (Layout::Section_list::const_iterator p = section_list.begin();
11159 p != section_list.end();
11160 ++p)
11162 Arm_output_section<big_endian>* output_section =
11163 Arm_output_section<big_endian>::as_arm_output_section(*p);
11164 output_section->group_sections(group_size, stubs_always_after_branch,
11165 this);
11169 // Relaxation hook. This is where we do stub generation.
11171 template<bool big_endian>
11172 bool
11173 Target_arm<big_endian>::do_relax(
11174 int pass,
11175 const Input_objects* input_objects,
11176 Symbol_table* symtab,
11177 Layout* layout)
11179 // No need to generate stubs if this is a relocatable link.
11180 gold_assert(!parameters->options().relocatable());
11182 // If this is the first pass, we need to group input sections into
11183 // stub groups.
11184 bool done_exidx_fixup = false;
11185 typedef typename Stub_table_list::iterator Stub_table_iterator;
11186 if (pass == 1)
11188 // Determine the stub group size. The group size is the absolute
11189 // value of the parameter --stub-group-size. If --stub-group-size
11190 // is passed a negative value, we restict stubs to be always after
11191 // the stubbed branches.
11192 int32_t stub_group_size_param =
11193 parameters->options().stub_group_size();
11194 bool stubs_always_after_branch = stub_group_size_param < 0;
11195 section_size_type stub_group_size = abs(stub_group_size_param);
11197 if (stub_group_size == 1)
11199 // Default value.
11200 // Thumb branch range is +-4MB has to be used as the default
11201 // maximum size (a given section can contain both ARM and Thumb
11202 // code, so the worst case has to be taken into account). If we are
11203 // fixing cortex-a8 errata, the branch range has to be even smaller,
11204 // since wide conditional branch has a range of +-1MB only.
11206 // This value is 48K less than that, which allows for 4096
11207 // 12-byte stubs. If we exceed that, then we will fail to link.
11208 // The user will have to relink with an explicit group size
11209 // option.
11210 stub_group_size = 4145152;
11213 // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11214 // page as the first half of a 32-bit branch straddling two 4K pages.
11215 // This is a crude way of enforcing that. In addition, long conditional
11216 // branches of THUMB-2 have a range of +-1M. If we are fixing cortex-A8
11217 // erratum, limit the group size to (1M - 12k) to avoid unreachable
11218 // cortex-A8 stubs from long conditional branches.
11219 if (this->fix_cortex_a8_)
11221 stubs_always_after_branch = true;
11222 const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11223 stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11226 group_sections(layout, stub_group_size, stubs_always_after_branch);
11228 // Also fix .ARM.exidx section coverage.
11229 Arm_output_section<big_endian>* exidx_output_section = NULL;
11230 for (Layout::Section_list::const_iterator p =
11231 layout->section_list().begin();
11232 p != layout->section_list().end();
11233 ++p)
11234 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11236 if (exidx_output_section == NULL)
11237 exidx_output_section =
11238 Arm_output_section<big_endian>::as_arm_output_section(*p);
11239 else
11240 // We cannot handle this now.
11241 gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11242 "non-relocatable link"),
11243 exidx_output_section->name(),
11244 (*p)->name());
11247 if (exidx_output_section != NULL)
11249 this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11250 symtab);
11251 done_exidx_fixup = true;
11254 else
11256 // If this is not the first pass, addresses and file offsets have
11257 // been reset at this point, set them here.
11258 for (Stub_table_iterator sp = this->stub_tables_.begin();
11259 sp != this->stub_tables_.end();
11260 ++sp)
11262 Arm_input_section<big_endian>* owner = (*sp)->owner();
11263 off_t off = align_address(owner->original_size(),
11264 (*sp)->addralign());
11265 (*sp)->set_address_and_file_offset(owner->address() + off,
11266 owner->offset() + off);
11270 // The Cortex-A8 stubs are sensitive to layout of code sections. At the
11271 // beginning of each relaxation pass, just blow away all the stubs.
11272 // Alternatively, we could selectively remove only the stubs and reloc
11273 // information for code sections that have moved since the last pass.
11274 // That would require more book-keeping.
11275 if (this->fix_cortex_a8_)
11277 // Clear all Cortex-A8 reloc information.
11278 for (typename Cortex_a8_relocs_info::const_iterator p =
11279 this->cortex_a8_relocs_info_.begin();
11280 p != this->cortex_a8_relocs_info_.end();
11281 ++p)
11282 delete p->second;
11283 this->cortex_a8_relocs_info_.clear();
11285 // Remove all Cortex-A8 stubs.
11286 for (Stub_table_iterator sp = this->stub_tables_.begin();
11287 sp != this->stub_tables_.end();
11288 ++sp)
11289 (*sp)->remove_all_cortex_a8_stubs();
11292 // Scan relocs for relocation stubs
11293 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11294 op != input_objects->relobj_end();
11295 ++op)
11297 Arm_relobj<big_endian>* arm_relobj =
11298 Arm_relobj<big_endian>::as_arm_relobj(*op);
11299 arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11302 // Check all stub tables to see if any of them have their data sizes
11303 // or addresses alignments changed. These are the only things that
11304 // matter.
11305 bool any_stub_table_changed = false;
11306 Unordered_set<const Output_section*> sections_needing_adjustment;
11307 for (Stub_table_iterator sp = this->stub_tables_.begin();
11308 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11309 ++sp)
11311 if ((*sp)->update_data_size_and_addralign())
11313 // Update data size of stub table owner.
11314 Arm_input_section<big_endian>* owner = (*sp)->owner();
11315 uint64_t address = owner->address();
11316 off_t offset = owner->offset();
11317 owner->reset_address_and_file_offset();
11318 owner->set_address_and_file_offset(address, offset);
11320 sections_needing_adjustment.insert(owner->output_section());
11321 any_stub_table_changed = true;
11325 // Output_section_data::output_section() returns a const pointer but we
11326 // need to update output sections, so we record all output sections needing
11327 // update above and scan the sections here to find out what sections need
11328 // to be updated.
11329 for(Layout::Section_list::const_iterator p = layout->section_list().begin();
11330 p != layout->section_list().end();
11331 ++p)
11333 if (sections_needing_adjustment.find(*p)
11334 != sections_needing_adjustment.end())
11335 (*p)->set_section_offsets_need_adjustment();
11338 // Stop relaxation if no EXIDX fix-up and no stub table change.
11339 bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11341 // Finalize the stubs in the last relaxation pass.
11342 if (!continue_relaxation)
11344 for (Stub_table_iterator sp = this->stub_tables_.begin();
11345 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11346 ++sp)
11347 (*sp)->finalize_stubs();
11349 // Update output local symbol counts of objects if necessary.
11350 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11351 op != input_objects->relobj_end();
11352 ++op)
11354 Arm_relobj<big_endian>* arm_relobj =
11355 Arm_relobj<big_endian>::as_arm_relobj(*op);
11357 // Update output local symbol counts. We need to discard local
11358 // symbols defined in parts of input sections that are discarded by
11359 // relaxation.
11360 if (arm_relobj->output_local_symbol_count_needs_update())
11361 arm_relobj->update_output_local_symbol_count();
11365 return continue_relaxation;
11368 // Relocate a stub.
11370 template<bool big_endian>
11371 void
11372 Target_arm<big_endian>::relocate_stub(
11373 Stub* stub,
11374 const Relocate_info<32, big_endian>* relinfo,
11375 Output_section* output_section,
11376 unsigned char* view,
11377 Arm_address address,
11378 section_size_type view_size)
11380 Relocate relocate;
11381 const Stub_template* stub_template = stub->stub_template();
11382 for (size_t i = 0; i < stub_template->reloc_count(); i++)
11384 size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11385 const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11387 unsigned int r_type = insn->r_type();
11388 section_size_type reloc_offset = stub_template->reloc_offset(i);
11389 section_size_type reloc_size = insn->size();
11390 gold_assert(reloc_offset + reloc_size <= view_size);
11392 // This is the address of the stub destination.
11393 Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11394 Symbol_value<32> symval;
11395 symval.set_output_value(target);
11397 // Synthesize a fake reloc just in case. We don't have a symbol so
11398 // we use 0.
11399 unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11400 memset(reloc_buffer, 0, sizeof(reloc_buffer));
11401 elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11402 reloc_write.put_r_offset(reloc_offset);
11403 reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11404 elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11406 relocate.relocate(relinfo, this, output_section,
11407 this->fake_relnum_for_stubs, rel, r_type,
11408 NULL, &symval, view + reloc_offset,
11409 address + reloc_offset, reloc_size);
11413 // Determine whether an object attribute tag takes an integer, a
11414 // string or both.
11416 template<bool big_endian>
11418 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11420 if (tag == Object_attribute::Tag_compatibility)
11421 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11422 | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11423 else if (tag == elfcpp::Tag_nodefaults)
11424 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11425 | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11426 else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11427 return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11428 else if (tag < 32)
11429 return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11430 else
11431 return ((tag & 1) != 0
11432 ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11433 : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11436 // Reorder attributes.
11438 // The ABI defines that Tag_conformance should be emitted first, and that
11439 // Tag_nodefaults should be second (if either is defined). This sets those
11440 // two positions, and bumps up the position of all the remaining tags to
11441 // compensate.
11443 template<bool big_endian>
11445 Target_arm<big_endian>::do_attributes_order(int num) const
11447 // Reorder the known object attributes in output. We want to move
11448 // Tag_conformance to position 4 and Tag_conformance to position 5
11449 // and shift eveything between 4 .. Tag_conformance - 1 to make room.
11450 if (num == 4)
11451 return elfcpp::Tag_conformance;
11452 if (num == 5)
11453 return elfcpp::Tag_nodefaults;
11454 if ((num - 2) < elfcpp::Tag_nodefaults)
11455 return num - 2;
11456 if ((num - 1) < elfcpp::Tag_conformance)
11457 return num - 1;
11458 return num;
11461 // Scan a span of THUMB code for Cortex-A8 erratum.
11463 template<bool big_endian>
11464 void
11465 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11466 Arm_relobj<big_endian>* arm_relobj,
11467 unsigned int shndx,
11468 section_size_type span_start,
11469 section_size_type span_end,
11470 const unsigned char* view,
11471 Arm_address address)
11473 // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11475 // The opcode is BLX.W, BL.W, B.W, Bcc.W
11476 // The branch target is in the same 4KB region as the
11477 // first half of the branch.
11478 // The instruction before the branch is a 32-bit
11479 // length non-branch instruction.
11480 section_size_type i = span_start;
11481 bool last_was_32bit = false;
11482 bool last_was_branch = false;
11483 while (i < span_end)
11485 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11486 const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11487 uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11488 bool is_blx = false, is_b = false;
11489 bool is_bl = false, is_bcc = false;
11491 bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11492 if (insn_32bit)
11494 // Load the rest of the insn (in manual-friendly order).
11495 insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11497 // Encoding T4: B<c>.W.
11498 is_b = (insn & 0xf800d000U) == 0xf0009000U;
11499 // Encoding T1: BL<c>.W.
11500 is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11501 // Encoding T2: BLX<c>.W.
11502 is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11503 // Encoding T3: B<c>.W (not permitted in IT block).
11504 is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11505 && (insn & 0x07f00000U) != 0x03800000U);
11508 bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11510 // If this instruction is a 32-bit THUMB branch that crosses a 4K
11511 // page boundary and it follows 32-bit non-branch instruction,
11512 // we need to work around.
11513 if (is_32bit_branch
11514 && ((address + i) & 0xfffU) == 0xffeU
11515 && last_was_32bit
11516 && !last_was_branch)
11518 // Check to see if there is a relocation stub for this branch.
11519 bool force_target_arm = false;
11520 bool force_target_thumb = false;
11521 const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11522 Cortex_a8_relocs_info::const_iterator p =
11523 this->cortex_a8_relocs_info_.find(address + i);
11525 if (p != this->cortex_a8_relocs_info_.end())
11527 cortex_a8_reloc = p->second;
11528 bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11530 if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11531 && !target_is_thumb)
11532 force_target_arm = true;
11533 else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11534 && target_is_thumb)
11535 force_target_thumb = true;
11538 off_t offset;
11539 Stub_type stub_type = arm_stub_none;
11541 // Check if we have an offending branch instruction.
11542 uint16_t upper_insn = (insn >> 16) & 0xffffU;
11543 uint16_t lower_insn = insn & 0xffffU;
11544 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
11546 if (cortex_a8_reloc != NULL
11547 && cortex_a8_reloc->reloc_stub() != NULL)
11548 // We've already made a stub for this instruction, e.g.
11549 // it's a long branch or a Thumb->ARM stub. Assume that
11550 // stub will suffice to work around the A8 erratum (see
11551 // setting of always_after_branch above).
11553 else if (is_bcc)
11555 offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11556 lower_insn);
11557 stub_type = arm_stub_a8_veneer_b_cond;
11559 else if (is_b || is_bl || is_blx)
11561 offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11562 lower_insn);
11563 if (is_blx)
11564 offset &= ~3;
11566 stub_type = (is_blx
11567 ? arm_stub_a8_veneer_blx
11568 : (is_bl
11569 ? arm_stub_a8_veneer_bl
11570 : arm_stub_a8_veneer_b));
11573 if (stub_type != arm_stub_none)
11575 Arm_address pc_for_insn = address + i + 4;
11577 // The original instruction is a BL, but the target is
11578 // an ARM instruction. If we were not making a stub,
11579 // the BL would have been converted to a BLX. Use the
11580 // BLX stub instead in that case.
11581 if (this->may_use_blx() && force_target_arm
11582 && stub_type == arm_stub_a8_veneer_bl)
11584 stub_type = arm_stub_a8_veneer_blx;
11585 is_blx = true;
11586 is_bl = false;
11588 // Conversely, if the original instruction was
11589 // BLX but the target is Thumb mode, use the BL stub.
11590 else if (force_target_thumb
11591 && stub_type == arm_stub_a8_veneer_blx)
11593 stub_type = arm_stub_a8_veneer_bl;
11594 is_blx = false;
11595 is_bl = true;
11598 if (is_blx)
11599 pc_for_insn &= ~3;
11601 // If we found a relocation, use the proper destination,
11602 // not the offset in the (unrelocated) instruction.
11603 // Note this is always done if we switched the stub type above.
11604 if (cortex_a8_reloc != NULL)
11605 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11607 Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11609 // Add a new stub if destination address in in the same page.
11610 if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11612 Cortex_a8_stub* stub =
11613 this->stub_factory_.make_cortex_a8_stub(stub_type,
11614 arm_relobj, shndx,
11615 address + i,
11616 target, insn);
11617 Stub_table<big_endian>* stub_table =
11618 arm_relobj->stub_table(shndx);
11619 gold_assert(stub_table != NULL);
11620 stub_table->add_cortex_a8_stub(address + i, stub);
11625 i += insn_32bit ? 4 : 2;
11626 last_was_32bit = insn_32bit;
11627 last_was_branch = is_32bit_branch;
11631 // Apply the Cortex-A8 workaround.
11633 template<bool big_endian>
11634 void
11635 Target_arm<big_endian>::apply_cortex_a8_workaround(
11636 const Cortex_a8_stub* stub,
11637 Arm_address stub_address,
11638 unsigned char* insn_view,
11639 Arm_address insn_address)
11641 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11642 Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
11643 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
11644 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
11645 off_t branch_offset = stub_address - (insn_address + 4);
11647 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
11648 switch (stub->stub_template()->type())
11650 case arm_stub_a8_veneer_b_cond:
11651 // For a conditional branch, we re-write it to be a uncondition
11652 // branch to the stub. We use the THUMB-2 encoding here.
11653 upper_insn = 0xf000U;
11654 lower_insn = 0xb800U;
11655 // Fall through
11656 case arm_stub_a8_veneer_b:
11657 case arm_stub_a8_veneer_bl:
11658 case arm_stub_a8_veneer_blx:
11659 if ((lower_insn & 0x5000U) == 0x4000U)
11660 // For a BLX instruction, make sure that the relocation is
11661 // rounded up to a word boundary. This follows the semantics of
11662 // the instruction which specifies that bit 1 of the target
11663 // address will come from bit 1 of the base address.
11664 branch_offset = (branch_offset + 2) & ~3;
11666 // Put BRANCH_OFFSET back into the insn.
11667 gold_assert(!utils::has_overflow<25>(branch_offset));
11668 upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
11669 lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
11670 break;
11672 default:
11673 gold_unreachable();
11676 // Put the relocated value back in the object file:
11677 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
11678 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
11681 template<bool big_endian>
11682 class Target_selector_arm : public Target_selector
11684 public:
11685 Target_selector_arm()
11686 : Target_selector(elfcpp::EM_ARM, 32, big_endian,
11687 (big_endian ? "elf32-bigarm" : "elf32-littlearm"))
11690 Target*
11691 do_instantiate_target()
11692 { return new Target_arm<big_endian>(); }
11695 // Fix .ARM.exidx section coverage.
11697 template<bool big_endian>
11698 void
11699 Target_arm<big_endian>::fix_exidx_coverage(
11700 Layout* layout,
11701 const Input_objects* input_objects,
11702 Arm_output_section<big_endian>* exidx_section,
11703 Symbol_table* symtab)
11705 // We need to look at all the input sections in output in ascending
11706 // order of of output address. We do that by building a sorted list
11707 // of output sections by addresses. Then we looks at the output sections
11708 // in order. The input sections in an output section are already sorted
11709 // by addresses within the output section.
11711 typedef std::set<Output_section*, output_section_address_less_than>
11712 Sorted_output_section_list;
11713 Sorted_output_section_list sorted_output_sections;
11715 // Find out all the output sections of input sections pointed by
11716 // EXIDX input sections.
11717 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
11718 p != input_objects->relobj_end();
11719 ++p)
11721 Arm_relobj<big_endian>* arm_relobj =
11722 Arm_relobj<big_endian>::as_arm_relobj(*p);
11723 std::vector<unsigned int> shndx_list;
11724 arm_relobj->get_exidx_shndx_list(&shndx_list);
11725 for (size_t i = 0; i < shndx_list.size(); ++i)
11727 const Arm_exidx_input_section* exidx_input_section =
11728 arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
11729 gold_assert(exidx_input_section != NULL);
11730 if (!exidx_input_section->has_errors())
11732 unsigned int text_shndx = exidx_input_section->link();
11733 Output_section* os = arm_relobj->output_section(text_shndx);
11734 if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
11735 sorted_output_sections.insert(os);
11740 // Go over the output sections in ascending order of output addresses.
11741 typedef typename Arm_output_section<big_endian>::Text_section_list
11742 Text_section_list;
11743 Text_section_list sorted_text_sections;
11744 for(typename Sorted_output_section_list::iterator p =
11745 sorted_output_sections.begin();
11746 p != sorted_output_sections.end();
11747 ++p)
11749 Arm_output_section<big_endian>* arm_output_section =
11750 Arm_output_section<big_endian>::as_arm_output_section(*p);
11751 arm_output_section->append_text_sections_to_list(&sorted_text_sections);
11754 exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
11755 merge_exidx_entries());
11758 Target_selector_arm<false> target_selector_arm;
11759 Target_selector_arm<true> target_selector_armbe;
11761 } // End anonymous namespace.