* incremental.cc: Include "libiberty.h".
[binutils.git] / gold / arm.cc
blobc141bc010f9803bf02523949b030688ffbe73f83
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 endianity-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_(), cortex_a8_stubs_(),
872 arm_v4bx_stubs_(0xf), prev_data_size_(0), prev_addralign_(1)
875 ~Stub_table()
878 // Owner of this stub table.
879 Arm_input_section<big_endian>*
880 owner() const
881 { return this->owner_; }
883 // Whether this stub table is empty.
884 bool
885 empty() const
887 return (this->reloc_stubs_.empty()
888 && this->cortex_a8_stubs_.empty()
889 && this->arm_v4bx_stubs_.empty());
892 // Return the current data size.
893 off_t
894 current_data_size() const
895 { return this->current_data_size_for_child(); }
897 // Add a STUB with using KEY. Caller is reponsible for avoid adding
898 // if already a STUB with the same key has been added.
899 void
900 add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key)
902 const Stub_template* stub_template = stub->stub_template();
903 gold_assert(stub_template->type() == key.stub_type());
904 this->reloc_stubs_[key] = stub;
907 // Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS.
908 // Caller is reponsible for avoid adding if already a STUB with the same
909 // address has been added.
910 void
911 add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub)
913 std::pair<Arm_address, Cortex_a8_stub*> value(address, stub);
914 this->cortex_a8_stubs_.insert(value);
917 // Add an ARM V4BX relocation stub. A register index will be retrieved
918 // from the stub.
919 void
920 add_arm_v4bx_stub(Arm_v4bx_stub* stub)
922 gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL);
923 this->arm_v4bx_stubs_[stub->reg()] = stub;
926 // Remove all Cortex-A8 stubs.
927 void
928 remove_all_cortex_a8_stubs();
930 // Look up a relocation stub using KEY. Return NULL if there is none.
931 Reloc_stub*
932 find_reloc_stub(const Reloc_stub::Key& key) const
934 typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
935 return (p != this->reloc_stubs_.end()) ? p->second : NULL;
938 // Look up an arm v4bx relocation stub using the register index.
939 // Return NULL if there is none.
940 Arm_v4bx_stub*
941 find_arm_v4bx_stub(const uint32_t reg) const
943 gold_assert(reg < 0xf);
944 return this->arm_v4bx_stubs_[reg];
947 // Relocate stubs in this stub table.
948 void
949 relocate_stubs(const Relocate_info<32, big_endian>*,
950 Target_arm<big_endian>*, Output_section*,
951 unsigned char*, Arm_address, section_size_type);
953 // Update data size and alignment at the end of a relaxation pass. Return
954 // true if either data size or alignment is different from that of the
955 // previous relaxation pass.
956 bool
957 update_data_size_and_addralign();
959 // Finalize stubs. Set the offsets of all stubs and mark input sections
960 // needing the Cortex-A8 workaround.
961 void
962 finalize_stubs();
964 // Apply Cortex-A8 workaround to an address range.
965 void
966 apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*,
967 unsigned char*, Arm_address,
968 section_size_type);
970 protected:
971 // Write out section contents.
972 void
973 do_write(Output_file*);
975 // Return the required alignment.
976 uint64_t
977 do_addralign() const
978 { return this->prev_addralign_; }
980 // Reset address and file offset.
981 void
982 do_reset_address_and_file_offset()
983 { this->set_current_data_size_for_child(this->prev_data_size_); }
985 // Set final data size.
986 void
987 set_final_data_size()
988 { this->set_data_size(this->current_data_size()); }
990 private:
991 // Relocate one stub.
992 void
993 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
994 Target_arm<big_endian>*, Output_section*,
995 unsigned char*, Arm_address, section_size_type);
997 // Unordered map of relocation stubs.
998 typedef
999 Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
1000 Reloc_stub::Key::equal_to>
1001 Reloc_stub_map;
1003 // List of Cortex-A8 stubs ordered by addresses of branches being
1004 // fixed up in output.
1005 typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list;
1006 // List of Arm V4BX relocation stubs ordered by associated registers.
1007 typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list;
1009 // Owner of this stub table.
1010 Arm_input_section<big_endian>* owner_;
1011 // The relocation stubs.
1012 Reloc_stub_map reloc_stubs_;
1013 // The cortex_a8_stubs.
1014 Cortex_a8_stub_list cortex_a8_stubs_;
1015 // The Arm V4BX relocation stubs.
1016 Arm_v4bx_stub_list arm_v4bx_stubs_;
1017 // data size of this in the previous pass.
1018 off_t prev_data_size_;
1019 // address alignment of this in the previous pass.
1020 uint64_t prev_addralign_;
1023 // Arm_exidx_cantunwind class. This represents an EXIDX_CANTUNWIND entry
1024 // we add to the end of an EXIDX input section that goes into the output.
1026 class Arm_exidx_cantunwind : public Output_section_data
1028 public:
1029 Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
1030 : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
1033 // Return the object containing the section pointed by this.
1034 Relobj*
1035 relobj() const
1036 { return this->relobj_; }
1038 // Return the section index of the section pointed by this.
1039 unsigned int
1040 shndx() const
1041 { return this->shndx_; }
1043 protected:
1044 void
1045 do_write(Output_file* of)
1047 if (parameters->target().is_big_endian())
1048 this->do_fixed_endian_write<true>(of);
1049 else
1050 this->do_fixed_endian_write<false>(of);
1053 private:
1054 // Implement do_write for a given endianity.
1055 template<bool big_endian>
1056 void inline
1057 do_fixed_endian_write(Output_file*);
1059 // The object containing the section pointed by this.
1060 Relobj* relobj_;
1061 // The section index of the section pointed by this.
1062 unsigned int shndx_;
1065 // During EXIDX coverage fix-up, we compact an EXIDX section. The
1066 // Offset map is used to map input section offset within the EXIDX section
1067 // to the output offset from the start of this EXIDX section.
1069 typedef std::map<section_offset_type, section_offset_type>
1070 Arm_exidx_section_offset_map;
1072 // Arm_exidx_merged_section class. This represents an EXIDX input section
1073 // with some of its entries merged.
1075 class Arm_exidx_merged_section : public Output_relaxed_input_section
1077 public:
1078 // Constructor for Arm_exidx_merged_section.
1079 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
1080 // SECTION_OFFSET_MAP points to a section offset map describing how
1081 // parts of the input section are mapped to output. DELETED_BYTES is
1082 // the number of bytes deleted from the EXIDX input section.
1083 Arm_exidx_merged_section(
1084 const Arm_exidx_input_section& exidx_input_section,
1085 const Arm_exidx_section_offset_map& section_offset_map,
1086 uint32_t deleted_bytes);
1088 // Return the original EXIDX input section.
1089 const Arm_exidx_input_section&
1090 exidx_input_section() const
1091 { return this->exidx_input_section_; }
1093 // Return the section offset map.
1094 const Arm_exidx_section_offset_map&
1095 section_offset_map() const
1096 { return this->section_offset_map_; }
1098 protected:
1099 // Write merged section into file OF.
1100 void
1101 do_write(Output_file* of);
1103 bool
1104 do_output_offset(const Relobj*, unsigned int, section_offset_type,
1105 section_offset_type*) const;
1107 private:
1108 // Original EXIDX input section.
1109 const Arm_exidx_input_section& exidx_input_section_;
1110 // Section offset map.
1111 const Arm_exidx_section_offset_map& section_offset_map_;
1114 // A class to wrap an ordinary input section containing executable code.
1116 template<bool big_endian>
1117 class Arm_input_section : public Output_relaxed_input_section
1119 public:
1120 Arm_input_section(Relobj* relobj, unsigned int shndx)
1121 : Output_relaxed_input_section(relobj, shndx, 1),
1122 original_addralign_(1), original_size_(0), stub_table_(NULL)
1125 ~Arm_input_section()
1128 // Initialize.
1129 void
1130 init();
1132 // Whether this is a stub table owner.
1133 bool
1134 is_stub_table_owner() const
1135 { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
1137 // Return the stub table.
1138 Stub_table<big_endian>*
1139 stub_table() const
1140 { return this->stub_table_; }
1142 // Set the stub_table.
1143 void
1144 set_stub_table(Stub_table<big_endian>* stub_table)
1145 { this->stub_table_ = stub_table; }
1147 // Downcast a base pointer to an Arm_input_section pointer. This is
1148 // not type-safe but we only use Arm_input_section not the base class.
1149 static Arm_input_section<big_endian>*
1150 as_arm_input_section(Output_relaxed_input_section* poris)
1151 { return static_cast<Arm_input_section<big_endian>*>(poris); }
1153 protected:
1154 // Write data to output file.
1155 void
1156 do_write(Output_file*);
1158 // Return required alignment of this.
1159 uint64_t
1160 do_addralign() const
1162 if (this->is_stub_table_owner())
1163 return std::max(this->stub_table_->addralign(),
1164 this->original_addralign_);
1165 else
1166 return this->original_addralign_;
1169 // Finalize data size.
1170 void
1171 set_final_data_size();
1173 // Reset address and file offset.
1174 void
1175 do_reset_address_and_file_offset();
1177 // Output offset.
1178 bool
1179 do_output_offset(const Relobj* object, unsigned int shndx,
1180 section_offset_type offset,
1181 section_offset_type* poutput) const
1183 if ((object == this->relobj())
1184 && (shndx == this->shndx())
1185 && (offset >= 0)
1186 && (convert_types<uint64_t, section_offset_type>(offset)
1187 <= this->original_size_))
1189 *poutput = offset;
1190 return true;
1192 else
1193 return false;
1196 private:
1197 // Copying is not allowed.
1198 Arm_input_section(const Arm_input_section&);
1199 Arm_input_section& operator=(const Arm_input_section&);
1201 // Address alignment of the original input section.
1202 uint64_t original_addralign_;
1203 // Section size of the original input section.
1204 uint64_t original_size_;
1205 // Stub table.
1206 Stub_table<big_endian>* stub_table_;
1209 // Arm_exidx_fixup class. This is used to define a number of methods
1210 // and keep states for fixing up EXIDX coverage.
1212 class Arm_exidx_fixup
1214 public:
1215 Arm_exidx_fixup(Output_section* exidx_output_section)
1216 : exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE),
1217 last_inlined_entry_(0), last_input_section_(NULL),
1218 section_offset_map_(NULL), first_output_text_section_(NULL)
1221 ~Arm_exidx_fixup()
1222 { delete this->section_offset_map_; }
1224 // Process an EXIDX section for entry merging. Return number of bytes to
1225 // be deleted in output. If parts of the input EXIDX section are merged
1226 // a heap allocated Arm_exidx_section_offset_map is store in the located
1227 // PSECTION_OFFSET_MAP. The caller owns the map and is reponsible for
1228 // releasing it.
1229 template<bool big_endian>
1230 uint32_t
1231 process_exidx_section(const Arm_exidx_input_section* exidx_input_section,
1232 Arm_exidx_section_offset_map** psection_offset_map);
1234 // Append an EXIDX_CANTUNWIND entry pointing at the end of the last
1235 // input section, if there is not one already.
1236 void
1237 add_exidx_cantunwind_as_needed();
1239 // Return the output section for the text section which is linked to the
1240 // first exidx input in output.
1241 Output_section*
1242 first_output_text_section() const
1243 { return this->first_output_text_section_; }
1245 private:
1246 // Copying is not allowed.
1247 Arm_exidx_fixup(const Arm_exidx_fixup&);
1248 Arm_exidx_fixup& operator=(const Arm_exidx_fixup&);
1250 // Type of EXIDX unwind entry.
1251 enum Unwind_type
1253 // No type.
1254 UT_NONE,
1255 // EXIDX_CANTUNWIND.
1256 UT_EXIDX_CANTUNWIND,
1257 // Inlined entry.
1258 UT_INLINED_ENTRY,
1259 // Normal entry.
1260 UT_NORMAL_ENTRY,
1263 // Process an EXIDX entry. We only care about the second word of the
1264 // entry. Return true if the entry can be deleted.
1265 bool
1266 process_exidx_entry(uint32_t second_word);
1268 // Update the current section offset map during EXIDX section fix-up.
1269 // If there is no map, create one. INPUT_OFFSET is the offset of a
1270 // reference point, DELETED_BYTES is the number of deleted by in the
1271 // section so far. If DELETE_ENTRY is true, the reference point and
1272 // all offsets after the previous reference point are discarded.
1273 void
1274 update_offset_map(section_offset_type input_offset,
1275 section_size_type deleted_bytes, bool delete_entry);
1277 // EXIDX output section.
1278 Output_section* exidx_output_section_;
1279 // Unwind type of the last EXIDX entry processed.
1280 Unwind_type last_unwind_type_;
1281 // Last seen inlined EXIDX entry.
1282 uint32_t last_inlined_entry_;
1283 // Last processed EXIDX input section.
1284 const Arm_exidx_input_section* last_input_section_;
1285 // Section offset map created in process_exidx_section.
1286 Arm_exidx_section_offset_map* section_offset_map_;
1287 // Output section for the text section which is linked to the first exidx
1288 // input in output.
1289 Output_section* first_output_text_section_;
1292 // Arm output section class. This is defined mainly to add a number of
1293 // stub generation methods.
1295 template<bool big_endian>
1296 class Arm_output_section : public Output_section
1298 public:
1299 typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list;
1301 Arm_output_section(const char* name, elfcpp::Elf_Word type,
1302 elfcpp::Elf_Xword flags)
1303 : Output_section(name, type, flags)
1306 ~Arm_output_section()
1309 // Group input sections for stub generation.
1310 void
1311 group_sections(section_size_type, bool, Target_arm<big_endian>*);
1313 // Downcast a base pointer to an Arm_output_section pointer. This is
1314 // not type-safe but we only use Arm_output_section not the base class.
1315 static Arm_output_section<big_endian>*
1316 as_arm_output_section(Output_section* os)
1317 { return static_cast<Arm_output_section<big_endian>*>(os); }
1319 // Append all input text sections in this into LIST.
1320 void
1321 append_text_sections_to_list(Text_section_list* list);
1323 // Fix EXIDX coverage of this EXIDX output section. SORTED_TEXT_SECTION
1324 // is a list of text input sections sorted in ascending order of their
1325 // output addresses.
1326 void
1327 fix_exidx_coverage(Layout* layout,
1328 const Text_section_list& sorted_text_section,
1329 Symbol_table* symtab);
1331 private:
1332 // For convenience.
1333 typedef Output_section::Input_section Input_section;
1334 typedef Output_section::Input_section_list Input_section_list;
1336 // Create a stub group.
1337 void create_stub_group(Input_section_list::const_iterator,
1338 Input_section_list::const_iterator,
1339 Input_section_list::const_iterator,
1340 Target_arm<big_endian>*,
1341 std::vector<Output_relaxed_input_section*>*);
1344 // Arm_exidx_input_section class. This represents an EXIDX input section.
1346 class Arm_exidx_input_section
1348 public:
1349 static const section_offset_type invalid_offset =
1350 static_cast<section_offset_type>(-1);
1352 Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1353 unsigned int link, uint32_t size, uint32_t addralign)
1354 : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1355 addralign_(addralign)
1358 ~Arm_exidx_input_section()
1361 // Accessors: This is a read-only class.
1363 // Return the object containing this EXIDX input section.
1364 Relobj*
1365 relobj() const
1366 { return this->relobj_; }
1368 // Return the section index of this EXIDX input section.
1369 unsigned int
1370 shndx() const
1371 { return this->shndx_; }
1373 // Return the section index of linked text section in the same object.
1374 unsigned int
1375 link() const
1376 { return this->link_; }
1378 // Return size of the EXIDX input section.
1379 uint32_t
1380 size() const
1381 { return this->size_; }
1383 // Reutnr address alignment of EXIDX input section.
1384 uint32_t
1385 addralign() const
1386 { return this->addralign_; }
1388 private:
1389 // Object containing this.
1390 Relobj* relobj_;
1391 // Section index of this.
1392 unsigned int shndx_;
1393 // text section linked to this in the same object.
1394 unsigned int link_;
1395 // Size of this. For ARM 32-bit is sufficient.
1396 uint32_t size_;
1397 // Address alignment of this. For ARM 32-bit is sufficient.
1398 uint32_t addralign_;
1401 // Arm_relobj class.
1403 template<bool big_endian>
1404 class Arm_relobj : public Sized_relobj<32, big_endian>
1406 public:
1407 static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1409 Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1410 const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1411 : Sized_relobj<32, big_endian>(name, input_file, offset, ehdr),
1412 stub_tables_(), local_symbol_is_thumb_function_(),
1413 attributes_section_data_(NULL), mapping_symbols_info_(),
1414 section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1415 output_local_symbol_count_needs_update_(false)
1418 ~Arm_relobj()
1419 { delete this->attributes_section_data_; }
1421 // Return the stub table of the SHNDX-th section if there is one.
1422 Stub_table<big_endian>*
1423 stub_table(unsigned int shndx) const
1425 gold_assert(shndx < this->stub_tables_.size());
1426 return this->stub_tables_[shndx];
1429 // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1430 void
1431 set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1433 gold_assert(shndx < this->stub_tables_.size());
1434 this->stub_tables_[shndx] = stub_table;
1437 // Whether a local symbol is a THUMB function. R_SYM is the symbol table
1438 // index. This is only valid after do_count_local_symbol is called.
1439 bool
1440 local_symbol_is_thumb_function(unsigned int r_sym) const
1442 gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1443 return this->local_symbol_is_thumb_function_[r_sym];
1446 // Scan all relocation sections for stub generation.
1447 void
1448 scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1449 const Layout*);
1451 // Convert regular input section with index SHNDX to a relaxed section.
1452 void
1453 convert_input_section_to_relaxed_section(unsigned shndx)
1455 // The stubs have relocations and we need to process them after writing
1456 // out the stubs. So relocation now must follow section write.
1457 this->set_section_offset(shndx, -1ULL);
1458 this->set_relocs_must_follow_section_writes();
1461 // Downcast a base pointer to an Arm_relobj pointer. This is
1462 // not type-safe but we only use Arm_relobj not the base class.
1463 static Arm_relobj<big_endian>*
1464 as_arm_relobj(Relobj* relobj)
1465 { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1467 // Processor-specific flags in ELF file header. This is valid only after
1468 // reading symbols.
1469 elfcpp::Elf_Word
1470 processor_specific_flags() const
1471 { return this->processor_specific_flags_; }
1473 // Attribute section data This is the contents of the .ARM.attribute section
1474 // if there is one.
1475 const Attributes_section_data*
1476 attributes_section_data() const
1477 { return this->attributes_section_data_; }
1479 // Mapping symbol location.
1480 typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1482 // Functor for STL container.
1483 struct Mapping_symbol_position_less
1485 bool
1486 operator()(const Mapping_symbol_position& p1,
1487 const Mapping_symbol_position& p2) const
1489 return (p1.first < p2.first
1490 || (p1.first == p2.first && p1.second < p2.second));
1494 // We only care about the first character of a mapping symbol, so
1495 // we only store that instead of the whole symbol name.
1496 typedef std::map<Mapping_symbol_position, char,
1497 Mapping_symbol_position_less> Mapping_symbols_info;
1499 // Whether a section contains any Cortex-A8 workaround.
1500 bool
1501 section_has_cortex_a8_workaround(unsigned int shndx) const
1503 return (this->section_has_cortex_a8_workaround_ != NULL
1504 && (*this->section_has_cortex_a8_workaround_)[shndx]);
1507 // Mark a section that has Cortex-A8 workaround.
1508 void
1509 mark_section_for_cortex_a8_workaround(unsigned int shndx)
1511 if (this->section_has_cortex_a8_workaround_ == NULL)
1512 this->section_has_cortex_a8_workaround_ =
1513 new std::vector<bool>(this->shnum(), false);
1514 (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1517 // Return the EXIDX section of an text section with index SHNDX or NULL
1518 // if the text section has no associated EXIDX section.
1519 const Arm_exidx_input_section*
1520 exidx_input_section_by_link(unsigned int shndx) const
1522 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1523 return ((p != this->exidx_section_map_.end()
1524 && p->second->link() == shndx)
1525 ? p->second
1526 : NULL);
1529 // Return the EXIDX section with index SHNDX or NULL if there is none.
1530 const Arm_exidx_input_section*
1531 exidx_input_section_by_shndx(unsigned shndx) const
1533 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1534 return ((p != this->exidx_section_map_.end()
1535 && p->second->shndx() == shndx)
1536 ? p->second
1537 : NULL);
1540 // Whether output local symbol count needs updating.
1541 bool
1542 output_local_symbol_count_needs_update() const
1543 { return this->output_local_symbol_count_needs_update_; }
1545 // Set output_local_symbol_count_needs_update flag to be true.
1546 void
1547 set_output_local_symbol_count_needs_update()
1548 { this->output_local_symbol_count_needs_update_ = true; }
1550 // Update output local symbol count at the end of relaxation.
1551 void
1552 update_output_local_symbol_count();
1554 protected:
1555 // Post constructor setup.
1556 void
1557 do_setup()
1559 // Call parent's setup method.
1560 Sized_relobj<32, big_endian>::do_setup();
1562 // Initialize look-up tables.
1563 Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1564 this->stub_tables_.swap(empty_stub_table_list);
1567 // Count the local symbols.
1568 void
1569 do_count_local_symbols(Stringpool_template<char>*,
1570 Stringpool_template<char>*);
1572 void
1573 do_relocate_sections(const Symbol_table* symtab, const Layout* layout,
1574 const unsigned char* pshdrs,
1575 typename Sized_relobj<32, big_endian>::Views* pivews);
1577 // Read the symbol information.
1578 void
1579 do_read_symbols(Read_symbols_data* sd);
1581 // Process relocs for garbage collection.
1582 void
1583 do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1585 private:
1587 // Whether a section needs to be scanned for relocation stubs.
1588 bool
1589 section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1590 const Relobj::Output_sections&,
1591 const Symbol_table *, const unsigned char*);
1593 // Whether a section is a scannable text section.
1594 bool
1595 section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1596 const Output_section*, const Symbol_table *);
1598 // Whether a section needs to be scanned for the Cortex-A8 erratum.
1599 bool
1600 section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1601 unsigned int, Output_section*,
1602 const Symbol_table *);
1604 // Scan a section for the Cortex-A8 erratum.
1605 void
1606 scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1607 unsigned int, Output_section*,
1608 Target_arm<big_endian>*);
1610 // Find the linked text section of an EXIDX section by looking at the
1611 // first reloction of the EXIDX section. PSHDR points to the section
1612 // headers of a relocation section and PSYMS points to the local symbols.
1613 // PSHNDX points to a location storing the text section index if found.
1614 // Return whether we can find the linked section.
1615 bool
1616 find_linked_text_section(const unsigned char* pshdr,
1617 const unsigned char* psyms, unsigned int* pshndx);
1620 // Make a new Arm_exidx_input_section object for EXIDX section with
1621 // index SHNDX and section header SHDR. TEXT_SHNDX is the section
1622 // index of the linked text section.
1623 void
1624 make_exidx_input_section(unsigned int shndx,
1625 const elfcpp::Shdr<32, big_endian>& shdr,
1626 unsigned int text_shndx);
1628 // Return the output address of either a plain input section or a
1629 // relaxed input section. SHNDX is the section index.
1630 Arm_address
1631 simple_input_section_output_address(unsigned int, Output_section*);
1633 typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1634 typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1635 Exidx_section_map;
1637 // List of stub tables.
1638 Stub_table_list stub_tables_;
1639 // Bit vector to tell if a local symbol is a thumb function or not.
1640 // This is only valid after do_count_local_symbol is called.
1641 std::vector<bool> local_symbol_is_thumb_function_;
1642 // processor-specific flags in ELF file header.
1643 elfcpp::Elf_Word processor_specific_flags_;
1644 // Object attributes if there is an .ARM.attributes section or NULL.
1645 Attributes_section_data* attributes_section_data_;
1646 // Mapping symbols information.
1647 Mapping_symbols_info mapping_symbols_info_;
1648 // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1649 std::vector<bool>* section_has_cortex_a8_workaround_;
1650 // Map a text section to its associated .ARM.exidx section, if there is one.
1651 Exidx_section_map exidx_section_map_;
1652 // Whether output local symbol count needs updating.
1653 bool output_local_symbol_count_needs_update_;
1656 // Arm_dynobj class.
1658 template<bool big_endian>
1659 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1661 public:
1662 Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1663 const elfcpp::Ehdr<32, big_endian>& ehdr)
1664 : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1665 processor_specific_flags_(0), attributes_section_data_(NULL)
1668 ~Arm_dynobj()
1669 { delete this->attributes_section_data_; }
1671 // Downcast a base pointer to an Arm_relobj pointer. This is
1672 // not type-safe but we only use Arm_relobj not the base class.
1673 static Arm_dynobj<big_endian>*
1674 as_arm_dynobj(Dynobj* dynobj)
1675 { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1677 // Processor-specific flags in ELF file header. This is valid only after
1678 // reading symbols.
1679 elfcpp::Elf_Word
1680 processor_specific_flags() const
1681 { return this->processor_specific_flags_; }
1683 // Attributes section data.
1684 const Attributes_section_data*
1685 attributes_section_data() const
1686 { return this->attributes_section_data_; }
1688 protected:
1689 // Read the symbol information.
1690 void
1691 do_read_symbols(Read_symbols_data* sd);
1693 private:
1694 // processor-specific flags in ELF file header.
1695 elfcpp::Elf_Word processor_specific_flags_;
1696 // Object attributes if there is an .ARM.attributes section or NULL.
1697 Attributes_section_data* attributes_section_data_;
1700 // Functor to read reloc addends during stub generation.
1702 template<int sh_type, bool big_endian>
1703 struct Stub_addend_reader
1705 // Return the addend for a relocation of a particular type. Depending
1706 // on whether this is a REL or RELA relocation, read the addend from a
1707 // view or from a Reloc object.
1708 elfcpp::Elf_types<32>::Elf_Swxword
1709 operator()(
1710 unsigned int /* r_type */,
1711 const unsigned char* /* view */,
1712 const typename Reloc_types<sh_type,
1713 32, big_endian>::Reloc& /* reloc */) const;
1716 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1718 template<bool big_endian>
1719 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1721 elfcpp::Elf_types<32>::Elf_Swxword
1722 operator()(
1723 unsigned int,
1724 const unsigned char*,
1725 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1728 // Specialized Stub_addend_reader for RELA type relocation sections.
1729 // We currently do not handle RELA type relocation sections but it is trivial
1730 // to implement the addend reader. This is provided for completeness and to
1731 // make it easier to add support for RELA relocation sections in the future.
1733 template<bool big_endian>
1734 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1736 elfcpp::Elf_types<32>::Elf_Swxword
1737 operator()(
1738 unsigned int,
1739 const unsigned char*,
1740 const typename Reloc_types<elfcpp::SHT_RELA, 32,
1741 big_endian>::Reloc& reloc) const
1742 { return reloc.get_r_addend(); }
1745 // Cortex_a8_reloc class. We keep record of relocation that may need
1746 // the Cortex-A8 erratum workaround.
1748 class Cortex_a8_reloc
1750 public:
1751 Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1752 Arm_address destination)
1753 : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1756 ~Cortex_a8_reloc()
1759 // Accessors: This is a read-only class.
1761 // Return the relocation stub associated with this relocation if there is
1762 // one.
1763 const Reloc_stub*
1764 reloc_stub() const
1765 { return this->reloc_stub_; }
1767 // Return the relocation type.
1768 unsigned int
1769 r_type() const
1770 { return this->r_type_; }
1772 // Return the destination address of the relocation. LSB stores the THUMB
1773 // bit.
1774 Arm_address
1775 destination() const
1776 { return this->destination_; }
1778 private:
1779 // Associated relocation stub if there is one, or NULL.
1780 const Reloc_stub* reloc_stub_;
1781 // Relocation type.
1782 unsigned int r_type_;
1783 // Destination address of this relocation. LSB is used to distinguish
1784 // ARM/THUMB mode.
1785 Arm_address destination_;
1788 // Arm_output_data_got class. We derive this from Output_data_got to add
1789 // extra methods to handle TLS relocations in a static link.
1791 template<bool big_endian>
1792 class Arm_output_data_got : public Output_data_got<32, big_endian>
1794 public:
1795 Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1796 : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1799 // Add a static entry for the GOT entry at OFFSET. GSYM is a global
1800 // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1801 // applied in a static link.
1802 void
1803 add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1804 { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1806 // Add a static reloc for the GOT entry at OFFSET. RELOBJ is an object
1807 // defining a local symbol with INDEX. R_TYPE is the code of a dynamic
1808 // relocation that needs to be applied in a static link.
1809 void
1810 add_static_reloc(unsigned int got_offset, unsigned int r_type,
1811 Sized_relobj<32, big_endian>* relobj, unsigned int index)
1813 this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1814 index));
1817 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
1818 // The first one is initialized to be 1, which is the module index for
1819 // the main executable and the second one 0. A reloc of the type
1820 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1821 // be applied by gold. GSYM is a global symbol.
1822 void
1823 add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1825 // Same as the above but for a local symbol in OBJECT with INDEX.
1826 void
1827 add_tls_gd32_with_static_reloc(unsigned int got_type,
1828 Sized_relobj<32, big_endian>* object,
1829 unsigned int index);
1831 protected:
1832 // Write out the GOT table.
1833 void
1834 do_write(Output_file*);
1836 private:
1837 // This class represent dynamic relocations that need to be applied by
1838 // gold because we are using TLS relocations in a static link.
1839 class Static_reloc
1841 public:
1842 Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1843 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1844 { this->u_.global.symbol = gsym; }
1846 Static_reloc(unsigned int got_offset, unsigned int r_type,
1847 Sized_relobj<32, big_endian>* relobj, unsigned int index)
1848 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1850 this->u_.local.relobj = relobj;
1851 this->u_.local.index = index;
1854 // Return the GOT offset.
1855 unsigned int
1856 got_offset() const
1857 { return this->got_offset_; }
1859 // Relocation type.
1860 unsigned int
1861 r_type() const
1862 { return this->r_type_; }
1864 // Whether the symbol is global or not.
1865 bool
1866 symbol_is_global() const
1867 { return this->symbol_is_global_; }
1869 // For a relocation against a global symbol, the global symbol.
1870 Symbol*
1871 symbol() const
1873 gold_assert(this->symbol_is_global_);
1874 return this->u_.global.symbol;
1877 // For a relocation against a local symbol, the defining object.
1878 Sized_relobj<32, big_endian>*
1879 relobj() const
1881 gold_assert(!this->symbol_is_global_);
1882 return this->u_.local.relobj;
1885 // For a relocation against a local symbol, the local symbol index.
1886 unsigned int
1887 index() const
1889 gold_assert(!this->symbol_is_global_);
1890 return this->u_.local.index;
1893 private:
1894 // GOT offset of the entry to which this relocation is applied.
1895 unsigned int got_offset_;
1896 // Type of relocation.
1897 unsigned int r_type_;
1898 // Whether this relocation is against a global symbol.
1899 bool symbol_is_global_;
1900 // A global or local symbol.
1901 union
1903 struct
1905 // For a global symbol, the symbol itself.
1906 Symbol* symbol;
1907 } global;
1908 struct
1910 // For a local symbol, the object defining object.
1911 Sized_relobj<32, big_endian>* relobj;
1912 // For a local symbol, the symbol index.
1913 unsigned int index;
1914 } local;
1915 } u_;
1918 // Symbol table of the output object.
1919 Symbol_table* symbol_table_;
1920 // Layout of the output object.
1921 Layout* layout_;
1922 // Static relocs to be applied to the GOT.
1923 std::vector<Static_reloc> static_relocs_;
1926 // Utilities for manipulating integers of up to 32-bits
1928 namespace utils
1930 // Sign extend an n-bit unsigned integer stored in an uint32_t into
1931 // an int32_t. NO_BITS must be between 1 to 32.
1932 template<int no_bits>
1933 static inline int32_t
1934 sign_extend(uint32_t bits)
1936 gold_assert(no_bits >= 0 && no_bits <= 32);
1937 if (no_bits == 32)
1938 return static_cast<int32_t>(bits);
1939 uint32_t mask = (~((uint32_t) 0)) >> (32 - no_bits);
1940 bits &= mask;
1941 uint32_t top_bit = 1U << (no_bits - 1);
1942 int32_t as_signed = static_cast<int32_t>(bits);
1943 return (bits & top_bit) ? as_signed + (-top_bit * 2) : as_signed;
1946 // Detects overflow of an NO_BITS integer stored in a uint32_t.
1947 template<int no_bits>
1948 static inline bool
1949 has_overflow(uint32_t bits)
1951 gold_assert(no_bits >= 0 && no_bits <= 32);
1952 if (no_bits == 32)
1953 return false;
1954 int32_t max = (1 << (no_bits - 1)) - 1;
1955 int32_t min = -(1 << (no_bits - 1));
1956 int32_t as_signed = static_cast<int32_t>(bits);
1957 return as_signed > max || as_signed < min;
1960 // Detects overflow of an NO_BITS integer stored in a uint32_t when it
1961 // fits in the given number of bits as either a signed or unsigned value.
1962 // For example, has_signed_unsigned_overflow<8> would check
1963 // -128 <= bits <= 255
1964 template<int no_bits>
1965 static inline bool
1966 has_signed_unsigned_overflow(uint32_t bits)
1968 gold_assert(no_bits >= 2 && no_bits <= 32);
1969 if (no_bits == 32)
1970 return false;
1971 int32_t max = static_cast<int32_t>((1U << no_bits) - 1);
1972 int32_t min = -(1 << (no_bits - 1));
1973 int32_t as_signed = static_cast<int32_t>(bits);
1974 return as_signed > max || as_signed < min;
1977 // Select bits from A and B using bits in MASK. For each n in [0..31],
1978 // the n-th bit in the result is chosen from the n-th bits of A and B.
1979 // A zero selects A and a one selects B.
1980 static inline uint32_t
1981 bit_select(uint32_t a, uint32_t b, uint32_t mask)
1982 { return (a & ~mask) | (b & mask); }
1985 template<bool big_endian>
1986 class Target_arm : public Sized_target<32, big_endian>
1988 public:
1989 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
1990 Reloc_section;
1992 // When were are relocating a stub, we pass this as the relocation number.
1993 static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
1995 Target_arm()
1996 : Sized_target<32, big_endian>(&arm_info),
1997 got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
1998 copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL),
1999 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2000 stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2001 may_use_blx_(false), should_force_pic_veneer_(false),
2002 arm_input_section_map_(), attributes_section_data_(NULL),
2003 fix_cortex_a8_(false), cortex_a8_relocs_info_()
2006 // Whether we can use BLX.
2007 bool
2008 may_use_blx() const
2009 { return this->may_use_blx_; }
2011 // Set use-BLX flag.
2012 void
2013 set_may_use_blx(bool value)
2014 { this->may_use_blx_ = value; }
2016 // Whether we force PCI branch veneers.
2017 bool
2018 should_force_pic_veneer() const
2019 { return this->should_force_pic_veneer_; }
2021 // Set PIC veneer flag.
2022 void
2023 set_should_force_pic_veneer(bool value)
2024 { this->should_force_pic_veneer_ = value; }
2026 // Whether we use THUMB-2 instructions.
2027 bool
2028 using_thumb2() const
2030 Object_attribute* attr =
2031 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2032 int arch = attr->int_value();
2033 return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2036 // Whether we use THUMB/THUMB-2 instructions only.
2037 bool
2038 using_thumb_only() const
2040 Object_attribute* attr =
2041 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2042 if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2043 && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2044 return false;
2045 attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2046 return attr->int_value() == 'M';
2049 // Whether we have an NOP instruction. If not, use mov r0, r0 instead.
2050 bool
2051 may_use_arm_nop() const
2053 Object_attribute* attr =
2054 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2055 int arch = attr->int_value();
2056 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2057 || arch == elfcpp::TAG_CPU_ARCH_V6K
2058 || arch == elfcpp::TAG_CPU_ARCH_V7
2059 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2062 // Whether we have THUMB-2 NOP.W instruction.
2063 bool
2064 may_use_thumb2_nop() const
2066 Object_attribute* attr =
2067 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2068 int arch = attr->int_value();
2069 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2070 || arch == elfcpp::TAG_CPU_ARCH_V7
2071 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2074 // Process the relocations to determine unreferenced sections for
2075 // garbage collection.
2076 void
2077 gc_process_relocs(Symbol_table* symtab,
2078 Layout* layout,
2079 Sized_relobj<32, big_endian>* object,
2080 unsigned int data_shndx,
2081 unsigned int sh_type,
2082 const unsigned char* prelocs,
2083 size_t reloc_count,
2084 Output_section* output_section,
2085 bool needs_special_offset_handling,
2086 size_t local_symbol_count,
2087 const unsigned char* plocal_symbols);
2089 // Scan the relocations to look for symbol adjustments.
2090 void
2091 scan_relocs(Symbol_table* symtab,
2092 Layout* layout,
2093 Sized_relobj<32, big_endian>* object,
2094 unsigned int data_shndx,
2095 unsigned int sh_type,
2096 const unsigned char* prelocs,
2097 size_t reloc_count,
2098 Output_section* output_section,
2099 bool needs_special_offset_handling,
2100 size_t local_symbol_count,
2101 const unsigned char* plocal_symbols);
2103 // Finalize the sections.
2104 void
2105 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2107 // Return the value to use for a dynamic symbol which requires special
2108 // treatment.
2109 uint64_t
2110 do_dynsym_value(const Symbol*) const;
2112 // Relocate a section.
2113 void
2114 relocate_section(const Relocate_info<32, big_endian>*,
2115 unsigned int sh_type,
2116 const unsigned char* prelocs,
2117 size_t reloc_count,
2118 Output_section* output_section,
2119 bool needs_special_offset_handling,
2120 unsigned char* view,
2121 Arm_address view_address,
2122 section_size_type view_size,
2123 const Reloc_symbol_changes*);
2125 // Scan the relocs during a relocatable link.
2126 void
2127 scan_relocatable_relocs(Symbol_table* symtab,
2128 Layout* layout,
2129 Sized_relobj<32, big_endian>* object,
2130 unsigned int data_shndx,
2131 unsigned int sh_type,
2132 const unsigned char* prelocs,
2133 size_t reloc_count,
2134 Output_section* output_section,
2135 bool needs_special_offset_handling,
2136 size_t local_symbol_count,
2137 const unsigned char* plocal_symbols,
2138 Relocatable_relocs*);
2140 // Relocate a section during a relocatable link.
2141 void
2142 relocate_for_relocatable(const Relocate_info<32, big_endian>*,
2143 unsigned int sh_type,
2144 const unsigned char* prelocs,
2145 size_t reloc_count,
2146 Output_section* output_section,
2147 off_t offset_in_output_section,
2148 const Relocatable_relocs*,
2149 unsigned char* view,
2150 Arm_address view_address,
2151 section_size_type view_size,
2152 unsigned char* reloc_view,
2153 section_size_type reloc_view_size);
2155 // Return whether SYM is defined by the ABI.
2156 bool
2157 do_is_defined_by_abi(Symbol* sym) const
2158 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2160 // Return whether there is a GOT section.
2161 bool
2162 has_got_section() const
2163 { return this->got_ != NULL; }
2165 // Return the size of the GOT section.
2166 section_size_type
2167 got_size()
2169 gold_assert(this->got_ != NULL);
2170 return this->got_->data_size();
2173 // Map platform-specific reloc types
2174 static unsigned int
2175 get_real_reloc_type (unsigned int r_type);
2178 // Methods to support stub-generations.
2181 // Return the stub factory
2182 const Stub_factory&
2183 stub_factory() const
2184 { return this->stub_factory_; }
2186 // Make a new Arm_input_section object.
2187 Arm_input_section<big_endian>*
2188 new_arm_input_section(Relobj*, unsigned int);
2190 // Find the Arm_input_section object corresponding to the SHNDX-th input
2191 // section of RELOBJ.
2192 Arm_input_section<big_endian>*
2193 find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2195 // Make a new Stub_table
2196 Stub_table<big_endian>*
2197 new_stub_table(Arm_input_section<big_endian>*);
2199 // Scan a section for stub generation.
2200 void
2201 scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2202 const unsigned char*, size_t, Output_section*,
2203 bool, const unsigned char*, Arm_address,
2204 section_size_type);
2206 // Relocate a stub.
2207 void
2208 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2209 Output_section*, unsigned char*, Arm_address,
2210 section_size_type);
2212 // Get the default ARM target.
2213 static Target_arm<big_endian>*
2214 default_target()
2216 gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2217 && parameters->target().is_big_endian() == big_endian);
2218 return static_cast<Target_arm<big_endian>*>(
2219 parameters->sized_target<32, big_endian>());
2222 // Whether NAME belongs to a mapping symbol.
2223 static bool
2224 is_mapping_symbol_name(const char* name)
2226 return (name
2227 && name[0] == '$'
2228 && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2229 && (name[2] == '\0' || name[2] == '.'));
2232 // Whether we work around the Cortex-A8 erratum.
2233 bool
2234 fix_cortex_a8() const
2235 { return this->fix_cortex_a8_; }
2237 // Whether we fix R_ARM_V4BX relocation.
2238 // 0 - do not fix
2239 // 1 - replace with MOV instruction (armv4 target)
2240 // 2 - make interworking veneer (>= armv4t targets only)
2241 General_options::Fix_v4bx
2242 fix_v4bx() const
2243 { return parameters->options().fix_v4bx(); }
2245 // Scan a span of THUMB code section for Cortex-A8 erratum.
2246 void
2247 scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2248 section_size_type, section_size_type,
2249 const unsigned char*, Arm_address);
2251 // Apply Cortex-A8 workaround to a branch.
2252 void
2253 apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2254 unsigned char*, Arm_address);
2256 protected:
2257 // Make an ELF object.
2258 Object*
2259 do_make_elf_object(const std::string&, Input_file*, off_t,
2260 const elfcpp::Ehdr<32, big_endian>& ehdr);
2262 Object*
2263 do_make_elf_object(const std::string&, Input_file*, off_t,
2264 const elfcpp::Ehdr<32, !big_endian>&)
2265 { gold_unreachable(); }
2267 Object*
2268 do_make_elf_object(const std::string&, Input_file*, off_t,
2269 const elfcpp::Ehdr<64, false>&)
2270 { gold_unreachable(); }
2272 Object*
2273 do_make_elf_object(const std::string&, Input_file*, off_t,
2274 const elfcpp::Ehdr<64, true>&)
2275 { gold_unreachable(); }
2277 // Make an output section.
2278 Output_section*
2279 do_make_output_section(const char* name, elfcpp::Elf_Word type,
2280 elfcpp::Elf_Xword flags)
2281 { return new Arm_output_section<big_endian>(name, type, flags); }
2283 void
2284 do_adjust_elf_header(unsigned char* view, int len) const;
2286 // We only need to generate stubs, and hence perform relaxation if we are
2287 // not doing relocatable linking.
2288 bool
2289 do_may_relax() const
2290 { return !parameters->options().relocatable(); }
2292 bool
2293 do_relax(int, const Input_objects*, Symbol_table*, Layout*);
2295 // Determine whether an object attribute tag takes an integer, a
2296 // string or both.
2298 do_attribute_arg_type(int tag) const;
2300 // Reorder tags during output.
2302 do_attributes_order(int num) const;
2304 // This is called when the target is selected as the default.
2305 void
2306 do_select_as_default_target()
2308 // No locking is required since there should only be one default target.
2309 // We cannot have both the big-endian and little-endian ARM targets
2310 // as the default.
2311 gold_assert(arm_reloc_property_table == NULL);
2312 arm_reloc_property_table = new Arm_reloc_property_table();
2315 private:
2316 // The class which scans relocations.
2317 class Scan
2319 public:
2320 Scan()
2321 : issued_non_pic_error_(false)
2324 inline void
2325 local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2326 Sized_relobj<32, big_endian>* object,
2327 unsigned int data_shndx,
2328 Output_section* output_section,
2329 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2330 const elfcpp::Sym<32, big_endian>& lsym);
2332 inline void
2333 global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2334 Sized_relobj<32, big_endian>* object,
2335 unsigned int data_shndx,
2336 Output_section* output_section,
2337 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2338 Symbol* gsym);
2340 inline bool
2341 local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2342 Sized_relobj<32, big_endian>* ,
2343 unsigned int ,
2344 Output_section* ,
2345 const elfcpp::Rel<32, big_endian>& ,
2346 unsigned int ,
2347 const elfcpp::Sym<32, big_endian>&)
2348 { return false; }
2350 inline bool
2351 global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2352 Sized_relobj<32, big_endian>* ,
2353 unsigned int ,
2354 Output_section* ,
2355 const elfcpp::Rel<32, big_endian>& ,
2356 unsigned int , Symbol*)
2357 { return false; }
2359 private:
2360 static void
2361 unsupported_reloc_local(Sized_relobj<32, big_endian>*,
2362 unsigned int r_type);
2364 static void
2365 unsupported_reloc_global(Sized_relobj<32, big_endian>*,
2366 unsigned int r_type, Symbol*);
2368 void
2369 check_non_pic(Relobj*, unsigned int r_type);
2371 // Almost identical to Symbol::needs_plt_entry except that it also
2372 // handles STT_ARM_TFUNC.
2373 static bool
2374 symbol_needs_plt_entry(const Symbol* sym)
2376 // An undefined symbol from an executable does not need a PLT entry.
2377 if (sym->is_undefined() && !parameters->options().shared())
2378 return false;
2380 return (!parameters->doing_static_link()
2381 && (sym->type() == elfcpp::STT_FUNC
2382 || sym->type() == elfcpp::STT_ARM_TFUNC)
2383 && (sym->is_from_dynobj()
2384 || sym->is_undefined()
2385 || sym->is_preemptible()));
2388 // Whether we have issued an error about a non-PIC compilation.
2389 bool issued_non_pic_error_;
2392 // The class which implements relocation.
2393 class Relocate
2395 public:
2396 Relocate()
2399 ~Relocate()
2402 // Return whether the static relocation needs to be applied.
2403 inline bool
2404 should_apply_static_reloc(const Sized_symbol<32>* gsym,
2405 int ref_flags,
2406 bool is_32bit,
2407 Output_section* output_section);
2409 // Do a relocation. Return false if the caller should not issue
2410 // any warnings about this relocation.
2411 inline bool
2412 relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2413 Output_section*, size_t relnum,
2414 const elfcpp::Rel<32, big_endian>&,
2415 unsigned int r_type, const Sized_symbol<32>*,
2416 const Symbol_value<32>*,
2417 unsigned char*, Arm_address,
2418 section_size_type);
2420 // Return whether we want to pass flag NON_PIC_REF for this
2421 // reloc. This means the relocation type accesses a symbol not via
2422 // GOT or PLT.
2423 static inline bool
2424 reloc_is_non_pic (unsigned int r_type)
2426 switch (r_type)
2428 // These relocation types reference GOT or PLT entries explicitly.
2429 case elfcpp::R_ARM_GOT_BREL:
2430 case elfcpp::R_ARM_GOT_ABS:
2431 case elfcpp::R_ARM_GOT_PREL:
2432 case elfcpp::R_ARM_GOT_BREL12:
2433 case elfcpp::R_ARM_PLT32_ABS:
2434 case elfcpp::R_ARM_TLS_GD32:
2435 case elfcpp::R_ARM_TLS_LDM32:
2436 case elfcpp::R_ARM_TLS_IE32:
2437 case elfcpp::R_ARM_TLS_IE12GP:
2439 // These relocate types may use PLT entries.
2440 case elfcpp::R_ARM_CALL:
2441 case elfcpp::R_ARM_THM_CALL:
2442 case elfcpp::R_ARM_JUMP24:
2443 case elfcpp::R_ARM_THM_JUMP24:
2444 case elfcpp::R_ARM_THM_JUMP19:
2445 case elfcpp::R_ARM_PLT32:
2446 case elfcpp::R_ARM_THM_XPC22:
2447 case elfcpp::R_ARM_PREL31:
2448 case elfcpp::R_ARM_SBREL31:
2449 return false;
2451 default:
2452 return true;
2456 private:
2457 // Do a TLS relocation.
2458 inline typename Arm_relocate_functions<big_endian>::Status
2459 relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2460 size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2461 const Sized_symbol<32>*, const Symbol_value<32>*,
2462 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2463 section_size_type);
2467 // A class which returns the size required for a relocation type,
2468 // used while scanning relocs during a relocatable link.
2469 class Relocatable_size_for_reloc
2471 public:
2472 unsigned int
2473 get_size_for_reloc(unsigned int, Relobj*);
2476 // Adjust TLS relocation type based on the options and whether this
2477 // is a local symbol.
2478 static tls::Tls_optimization
2479 optimize_tls_reloc(bool is_final, int r_type);
2481 // Get the GOT section, creating it if necessary.
2482 Arm_output_data_got<big_endian>*
2483 got_section(Symbol_table*, Layout*);
2485 // Get the GOT PLT section.
2486 Output_data_space*
2487 got_plt_section() const
2489 gold_assert(this->got_plt_ != NULL);
2490 return this->got_plt_;
2493 // Create a PLT entry for a global symbol.
2494 void
2495 make_plt_entry(Symbol_table*, Layout*, Symbol*);
2497 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2498 void
2499 define_tls_base_symbol(Symbol_table*, Layout*);
2501 // Create a GOT entry for the TLS module index.
2502 unsigned int
2503 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2504 Sized_relobj<32, big_endian>* object);
2506 // Get the PLT section.
2507 const Output_data_plt_arm<big_endian>*
2508 plt_section() const
2510 gold_assert(this->plt_ != NULL);
2511 return this->plt_;
2514 // Get the dynamic reloc section, creating it if necessary.
2515 Reloc_section*
2516 rel_dyn_section(Layout*);
2518 // Get the section to use for TLS_DESC relocations.
2519 Reloc_section*
2520 rel_tls_desc_section(Layout*) const;
2522 // Return true if the symbol may need a COPY relocation.
2523 // References from an executable object to non-function symbols
2524 // defined in a dynamic object may need a COPY relocation.
2525 bool
2526 may_need_copy_reloc(Symbol* gsym)
2528 return (gsym->type() != elfcpp::STT_ARM_TFUNC
2529 && gsym->may_need_copy_reloc());
2532 // Add a potential copy relocation.
2533 void
2534 copy_reloc(Symbol_table* symtab, Layout* layout,
2535 Sized_relobj<32, big_endian>* object,
2536 unsigned int shndx, Output_section* output_section,
2537 Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2539 this->copy_relocs_.copy_reloc(symtab, layout,
2540 symtab->get_sized_symbol<32>(sym),
2541 object, shndx, output_section, reloc,
2542 this->rel_dyn_section(layout));
2545 // Whether two EABI versions are compatible.
2546 static bool
2547 are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2549 // Merge processor-specific flags from input object and those in the ELF
2550 // header of the output.
2551 void
2552 merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2554 // Get the secondary compatible architecture.
2555 static int
2556 get_secondary_compatible_arch(const Attributes_section_data*);
2558 // Set the secondary compatible architecture.
2559 static void
2560 set_secondary_compatible_arch(Attributes_section_data*, int);
2562 static int
2563 tag_cpu_arch_combine(const char*, int, int*, int, int);
2565 // Helper to print AEABI enum tag value.
2566 static std::string
2567 aeabi_enum_name(unsigned int);
2569 // Return string value for TAG_CPU_name.
2570 static std::string
2571 tag_cpu_name_value(unsigned int);
2573 // Merge object attributes from input object and those in the output.
2574 void
2575 merge_object_attributes(const char*, const Attributes_section_data*);
2577 // Helper to get an AEABI object attribute
2578 Object_attribute*
2579 get_aeabi_object_attribute(int tag) const
2581 Attributes_section_data* pasd = this->attributes_section_data_;
2582 gold_assert(pasd != NULL);
2583 Object_attribute* attr =
2584 pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2585 gold_assert(attr != NULL);
2586 return attr;
2590 // Methods to support stub-generations.
2593 // Group input sections for stub generation.
2594 void
2595 group_sections(Layout*, section_size_type, bool);
2597 // Scan a relocation for stub generation.
2598 void
2599 scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2600 const Sized_symbol<32>*, unsigned int,
2601 const Symbol_value<32>*,
2602 elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2604 // Scan a relocation section for stub.
2605 template<int sh_type>
2606 void
2607 scan_reloc_section_for_stubs(
2608 const Relocate_info<32, big_endian>* relinfo,
2609 const unsigned char* prelocs,
2610 size_t reloc_count,
2611 Output_section* output_section,
2612 bool needs_special_offset_handling,
2613 const unsigned char* view,
2614 elfcpp::Elf_types<32>::Elf_Addr view_address,
2615 section_size_type);
2617 // Fix .ARM.exidx section coverage.
2618 void
2619 fix_exidx_coverage(Layout*, Arm_output_section<big_endian>*, Symbol_table*);
2621 // Functors for STL set.
2622 struct output_section_address_less_than
2624 bool
2625 operator()(const Output_section* s1, const Output_section* s2) const
2626 { return s1->address() < s2->address(); }
2629 // Information about this specific target which we pass to the
2630 // general Target structure.
2631 static const Target::Target_info arm_info;
2633 // The types of GOT entries needed for this platform.
2634 enum Got_type
2636 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
2637 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
2638 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
2639 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
2640 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
2643 typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2645 // Map input section to Arm_input_section.
2646 typedef Unordered_map<Section_id,
2647 Arm_input_section<big_endian>*,
2648 Section_id_hash>
2649 Arm_input_section_map;
2651 // Map output addresses to relocs for Cortex-A8 erratum.
2652 typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2653 Cortex_a8_relocs_info;
2655 // The GOT section.
2656 Arm_output_data_got<big_endian>* got_;
2657 // The PLT section.
2658 Output_data_plt_arm<big_endian>* plt_;
2659 // The GOT PLT section.
2660 Output_data_space* got_plt_;
2661 // The dynamic reloc section.
2662 Reloc_section* rel_dyn_;
2663 // Relocs saved to avoid a COPY reloc.
2664 Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2665 // Space for variables copied with a COPY reloc.
2666 Output_data_space* dynbss_;
2667 // Offset of the GOT entry for the TLS module index.
2668 unsigned int got_mod_index_offset_;
2669 // True if the _TLS_MODULE_BASE_ symbol has been defined.
2670 bool tls_base_symbol_defined_;
2671 // Vector of Stub_tables created.
2672 Stub_table_list stub_tables_;
2673 // Stub factory.
2674 const Stub_factory &stub_factory_;
2675 // Whether we can use BLX.
2676 bool may_use_blx_;
2677 // Whether we force PIC branch veneers.
2678 bool should_force_pic_veneer_;
2679 // Map for locating Arm_input_sections.
2680 Arm_input_section_map arm_input_section_map_;
2681 // Attributes section data in output.
2682 Attributes_section_data* attributes_section_data_;
2683 // Whether we want to fix code for Cortex-A8 erratum.
2684 bool fix_cortex_a8_;
2685 // Map addresses to relocs for Cortex-A8 erratum.
2686 Cortex_a8_relocs_info cortex_a8_relocs_info_;
2689 template<bool big_endian>
2690 const Target::Target_info Target_arm<big_endian>::arm_info =
2692 32, // size
2693 big_endian, // is_big_endian
2694 elfcpp::EM_ARM, // machine_code
2695 false, // has_make_symbol
2696 false, // has_resolve
2697 false, // has_code_fill
2698 true, // is_default_stack_executable
2699 '\0', // wrap_char
2700 "/usr/lib/libc.so.1", // dynamic_linker
2701 0x8000, // default_text_segment_address
2702 0x1000, // abi_pagesize (overridable by -z max-page-size)
2703 0x1000, // common_pagesize (overridable by -z common-page-size)
2704 elfcpp::SHN_UNDEF, // small_common_shndx
2705 elfcpp::SHN_UNDEF, // large_common_shndx
2706 0, // small_common_section_flags
2707 0, // large_common_section_flags
2708 ".ARM.attributes", // attributes_section
2709 "aeabi" // attributes_vendor
2712 // Arm relocate functions class
2715 template<bool big_endian>
2716 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2718 public:
2719 typedef enum
2721 STATUS_OKAY, // No error during relocation.
2722 STATUS_OVERFLOW, // Relocation oveflow.
2723 STATUS_BAD_RELOC // Relocation cannot be applied.
2724 } Status;
2726 private:
2727 typedef Relocate_functions<32, big_endian> Base;
2728 typedef Arm_relocate_functions<big_endian> This;
2730 // Encoding of imm16 argument for movt and movw ARM instructions
2731 // from ARM ARM:
2733 // imm16 := imm4 | imm12
2735 // f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0
2736 // +-------+---------------+-------+-------+-----------------------+
2737 // | | |imm4 | |imm12 |
2738 // +-------+---------------+-------+-------+-----------------------+
2740 // Extract the relocation addend from VAL based on the ARM
2741 // instruction encoding described above.
2742 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2743 extract_arm_movw_movt_addend(
2744 typename elfcpp::Swap<32, big_endian>::Valtype val)
2746 // According to the Elf ABI for ARM Architecture the immediate
2747 // field is sign-extended to form the addend.
2748 return utils::sign_extend<16>(((val >> 4) & 0xf000) | (val & 0xfff));
2751 // Insert X into VAL based on the ARM instruction encoding described
2752 // above.
2753 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2754 insert_val_arm_movw_movt(
2755 typename elfcpp::Swap<32, big_endian>::Valtype val,
2756 typename elfcpp::Swap<32, big_endian>::Valtype x)
2758 val &= 0xfff0f000;
2759 val |= x & 0x0fff;
2760 val |= (x & 0xf000) << 4;
2761 return val;
2764 // Encoding of imm16 argument for movt and movw Thumb2 instructions
2765 // from ARM ARM:
2767 // imm16 := imm4 | i | imm3 | imm8
2769 // f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0
2770 // +---------+-+-----------+-------++-+-----+-------+---------------+
2771 // | |i| |imm4 || |imm3 | |imm8 |
2772 // +---------+-+-----------+-------++-+-----+-------+---------------+
2774 // Extract the relocation addend from VAL based on the Thumb2
2775 // instruction encoding described above.
2776 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2777 extract_thumb_movw_movt_addend(
2778 typename elfcpp::Swap<32, big_endian>::Valtype val)
2780 // According to the Elf ABI for ARM Architecture the immediate
2781 // field is sign-extended to form the addend.
2782 return utils::sign_extend<16>(((val >> 4) & 0xf000)
2783 | ((val >> 15) & 0x0800)
2784 | ((val >> 4) & 0x0700)
2785 | (val & 0x00ff));
2788 // Insert X into VAL based on the Thumb2 instruction encoding
2789 // described above.
2790 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2791 insert_val_thumb_movw_movt(
2792 typename elfcpp::Swap<32, big_endian>::Valtype val,
2793 typename elfcpp::Swap<32, big_endian>::Valtype x)
2795 val &= 0xfbf08f00;
2796 val |= (x & 0xf000) << 4;
2797 val |= (x & 0x0800) << 15;
2798 val |= (x & 0x0700) << 4;
2799 val |= (x & 0x00ff);
2800 return val;
2803 // Calculate the smallest constant Kn for the specified residual.
2804 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
2805 static uint32_t
2806 calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
2808 int32_t msb;
2810 if (residual == 0)
2811 return 0;
2812 // Determine the most significant bit in the residual and
2813 // align the resulting value to a 2-bit boundary.
2814 for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
2816 // The desired shift is now (msb - 6), or zero, whichever
2817 // is the greater.
2818 return (((msb - 6) < 0) ? 0 : (msb - 6));
2821 // Calculate the final residual for the specified group index.
2822 // If the passed group index is less than zero, the method will return
2823 // the value of the specified residual without any change.
2824 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
2825 static typename elfcpp::Swap<32, big_endian>::Valtype
2826 calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
2827 const int group)
2829 for (int n = 0; n <= group; n++)
2831 // Calculate which part of the value to mask.
2832 uint32_t shift = calc_grp_kn(residual);
2833 // Calculate the residual for the next time around.
2834 residual &= ~(residual & (0xff << shift));
2837 return residual;
2840 // Calculate the value of Gn for the specified group index.
2841 // We return it in the form of an encoded constant-and-rotation.
2842 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
2843 static typename elfcpp::Swap<32, big_endian>::Valtype
2844 calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
2845 const int group)
2847 typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
2848 uint32_t shift = 0;
2850 for (int n = 0; n <= group; n++)
2852 // Calculate which part of the value to mask.
2853 shift = calc_grp_kn(residual);
2854 // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
2855 gn = residual & (0xff << shift);
2856 // Calculate the residual for the next time around.
2857 residual &= ~gn;
2859 // Return Gn in the form of an encoded constant-and-rotation.
2860 return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
2863 public:
2864 // Handle ARM long branches.
2865 static typename This::Status
2866 arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
2867 unsigned char *, const Sized_symbol<32>*,
2868 const Arm_relobj<big_endian>*, unsigned int,
2869 const Symbol_value<32>*, Arm_address, Arm_address, bool);
2871 // Handle THUMB long branches.
2872 static typename This::Status
2873 thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
2874 unsigned char *, const Sized_symbol<32>*,
2875 const Arm_relobj<big_endian>*, unsigned int,
2876 const Symbol_value<32>*, Arm_address, Arm_address, bool);
2879 // Return the branch offset of a 32-bit THUMB branch.
2880 static inline int32_t
2881 thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
2883 // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
2884 // involving the J1 and J2 bits.
2885 uint32_t s = (upper_insn & (1U << 10)) >> 10;
2886 uint32_t upper = upper_insn & 0x3ffU;
2887 uint32_t lower = lower_insn & 0x7ffU;
2888 uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
2889 uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
2890 uint32_t i1 = j1 ^ s ? 0 : 1;
2891 uint32_t i2 = j2 ^ s ? 0 : 1;
2893 return utils::sign_extend<25>((s << 24) | (i1 << 23) | (i2 << 22)
2894 | (upper << 12) | (lower << 1));
2897 // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
2898 // UPPER_INSN is the original upper instruction of the branch. Caller is
2899 // responsible for overflow checking and BLX offset adjustment.
2900 static inline uint16_t
2901 thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
2903 uint32_t s = offset < 0 ? 1 : 0;
2904 uint32_t bits = static_cast<uint32_t>(offset);
2905 return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
2908 // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
2909 // LOWER_INSN is the original lower instruction of the branch. Caller is
2910 // responsible for overflow checking and BLX offset adjustment.
2911 static inline uint16_t
2912 thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
2914 uint32_t s = offset < 0 ? 1 : 0;
2915 uint32_t bits = static_cast<uint32_t>(offset);
2916 return ((lower_insn & ~0x2fffU)
2917 | ((((bits >> 23) & 1) ^ !s) << 13)
2918 | ((((bits >> 22) & 1) ^ !s) << 11)
2919 | ((bits >> 1) & 0x7ffU));
2922 // Return the branch offset of a 32-bit THUMB conditional branch.
2923 static inline int32_t
2924 thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
2926 uint32_t s = (upper_insn & 0x0400U) >> 10;
2927 uint32_t j1 = (lower_insn & 0x2000U) >> 13;
2928 uint32_t j2 = (lower_insn & 0x0800U) >> 11;
2929 uint32_t lower = (lower_insn & 0x07ffU);
2930 uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
2932 return utils::sign_extend<21>((upper << 12) | (lower << 1));
2935 // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
2936 // instruction. UPPER_INSN is the original upper instruction of the branch.
2937 // Caller is responsible for overflow checking.
2938 static inline uint16_t
2939 thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
2941 uint32_t s = offset < 0 ? 1 : 0;
2942 uint32_t bits = static_cast<uint32_t>(offset);
2943 return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
2946 // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
2947 // instruction. LOWER_INSN is the original lower instruction of the branch.
2948 // Caller is reponsible for overflow checking.
2949 static inline uint16_t
2950 thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
2952 uint32_t bits = static_cast<uint32_t>(offset);
2953 uint32_t j2 = (bits & 0x00080000U) >> 19;
2954 uint32_t j1 = (bits & 0x00040000U) >> 18;
2955 uint32_t lo = (bits & 0x00000ffeU) >> 1;
2957 return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
2960 // R_ARM_ABS8: S + A
2961 static inline typename This::Status
2962 abs8(unsigned char *view,
2963 const Sized_relobj<32, big_endian>* object,
2964 const Symbol_value<32>* psymval)
2966 typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
2967 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
2968 Valtype* wv = reinterpret_cast<Valtype*>(view);
2969 Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
2970 Reltype addend = utils::sign_extend<8>(val);
2971 Reltype x = psymval->value(object, addend);
2972 val = utils::bit_select(val, x, 0xffU);
2973 elfcpp::Swap<8, big_endian>::writeval(wv, val);
2974 return (utils::has_signed_unsigned_overflow<8>(x)
2975 ? This::STATUS_OVERFLOW
2976 : This::STATUS_OKAY);
2979 // R_ARM_THM_ABS5: S + A
2980 static inline typename This::Status
2981 thm_abs5(unsigned char *view,
2982 const Sized_relobj<32, big_endian>* object,
2983 const Symbol_value<32>* psymval)
2985 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
2986 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
2987 Valtype* wv = reinterpret_cast<Valtype*>(view);
2988 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
2989 Reltype addend = (val & 0x7e0U) >> 6;
2990 Reltype x = psymval->value(object, addend);
2991 val = utils::bit_select(val, x << 6, 0x7e0U);
2992 elfcpp::Swap<16, big_endian>::writeval(wv, val);
2993 return (utils::has_overflow<5>(x)
2994 ? This::STATUS_OVERFLOW
2995 : This::STATUS_OKAY);
2998 // R_ARM_ABS12: S + A
2999 static inline typename This::Status
3000 abs12(unsigned char *view,
3001 const Sized_relobj<32, big_endian>* object,
3002 const Symbol_value<32>* psymval)
3004 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3005 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3006 Valtype* wv = reinterpret_cast<Valtype*>(view);
3007 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3008 Reltype addend = val & 0x0fffU;
3009 Reltype x = psymval->value(object, addend);
3010 val = utils::bit_select(val, x, 0x0fffU);
3011 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3012 return (utils::has_overflow<12>(x)
3013 ? This::STATUS_OVERFLOW
3014 : This::STATUS_OKAY);
3017 // R_ARM_ABS16: S + A
3018 static inline typename This::Status
3019 abs16(unsigned char *view,
3020 const Sized_relobj<32, big_endian>* object,
3021 const Symbol_value<32>* psymval)
3023 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3024 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3025 Valtype* wv = reinterpret_cast<Valtype*>(view);
3026 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3027 Reltype addend = utils::sign_extend<16>(val);
3028 Reltype x = psymval->value(object, addend);
3029 val = utils::bit_select(val, x, 0xffffU);
3030 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3031 return (utils::has_signed_unsigned_overflow<16>(x)
3032 ? This::STATUS_OVERFLOW
3033 : This::STATUS_OKAY);
3036 // R_ARM_ABS32: (S + A) | T
3037 static inline typename This::Status
3038 abs32(unsigned char *view,
3039 const Sized_relobj<32, big_endian>* object,
3040 const Symbol_value<32>* psymval,
3041 Arm_address thumb_bit)
3043 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3044 Valtype* wv = reinterpret_cast<Valtype*>(view);
3045 Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
3046 Valtype x = psymval->value(object, addend) | thumb_bit;
3047 elfcpp::Swap<32, big_endian>::writeval(wv, x);
3048 return This::STATUS_OKAY;
3051 // R_ARM_REL32: (S + A) | T - P
3052 static inline typename This::Status
3053 rel32(unsigned char *view,
3054 const Sized_relobj<32, big_endian>* object,
3055 const Symbol_value<32>* psymval,
3056 Arm_address address,
3057 Arm_address thumb_bit)
3059 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3060 Valtype* wv = reinterpret_cast<Valtype*>(view);
3061 Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
3062 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3063 elfcpp::Swap<32, big_endian>::writeval(wv, x);
3064 return This::STATUS_OKAY;
3067 // R_ARM_THM_JUMP24: (S + A) | T - P
3068 static typename This::Status
3069 thm_jump19(unsigned char *view, const Arm_relobj<big_endian>* object,
3070 const Symbol_value<32>* psymval, Arm_address address,
3071 Arm_address thumb_bit);
3073 // R_ARM_THM_JUMP6: S + A – P
3074 static inline typename This::Status
3075 thm_jump6(unsigned char *view,
3076 const Sized_relobj<32, big_endian>* object,
3077 const Symbol_value<32>* psymval,
3078 Arm_address address)
3080 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3081 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3082 Valtype* wv = reinterpret_cast<Valtype*>(view);
3083 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3084 // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3085 Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3086 Reltype x = (psymval->value(object, addend) - address);
3087 val = (val & 0xfd07) | ((x & 0x0040) << 3) | ((val & 0x003e) << 2);
3088 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3089 // CZB does only forward jumps.
3090 return ((x > 0x007e)
3091 ? This::STATUS_OVERFLOW
3092 : This::STATUS_OKAY);
3095 // R_ARM_THM_JUMP8: S + A – P
3096 static inline typename This::Status
3097 thm_jump8(unsigned char *view,
3098 const Sized_relobj<32, big_endian>* object,
3099 const Symbol_value<32>* psymval,
3100 Arm_address address)
3102 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3103 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3104 Valtype* wv = reinterpret_cast<Valtype*>(view);
3105 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3106 Reltype addend = utils::sign_extend<8>((val & 0x00ff) << 1);
3107 Reltype x = (psymval->value(object, addend) - address);
3108 elfcpp::Swap<16, big_endian>::writeval(wv, (val & 0xff00) | ((x & 0x01fe) >> 1));
3109 return (utils::has_overflow<8>(x)
3110 ? This::STATUS_OVERFLOW
3111 : This::STATUS_OKAY);
3114 // R_ARM_THM_JUMP11: S + A – P
3115 static inline typename This::Status
3116 thm_jump11(unsigned char *view,
3117 const Sized_relobj<32, big_endian>* object,
3118 const Symbol_value<32>* psymval,
3119 Arm_address address)
3121 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3122 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3123 Valtype* wv = reinterpret_cast<Valtype*>(view);
3124 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3125 Reltype addend = utils::sign_extend<11>((val & 0x07ff) << 1);
3126 Reltype x = (psymval->value(object, addend) - address);
3127 elfcpp::Swap<16, big_endian>::writeval(wv, (val & 0xf800) | ((x & 0x0ffe) >> 1));
3128 return (utils::has_overflow<11>(x)
3129 ? This::STATUS_OVERFLOW
3130 : This::STATUS_OKAY);
3133 // R_ARM_BASE_PREL: B(S) + A - P
3134 static inline typename This::Status
3135 base_prel(unsigned char* view,
3136 Arm_address origin,
3137 Arm_address address)
3139 Base::rel32(view, origin - address);
3140 return STATUS_OKAY;
3143 // R_ARM_BASE_ABS: B(S) + A
3144 static inline typename This::Status
3145 base_abs(unsigned char* view,
3146 Arm_address origin)
3148 Base::rel32(view, origin);
3149 return STATUS_OKAY;
3152 // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3153 static inline typename This::Status
3154 got_brel(unsigned char* view,
3155 typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3157 Base::rel32(view, got_offset);
3158 return This::STATUS_OKAY;
3161 // R_ARM_GOT_PREL: GOT(S) + A - P
3162 static inline typename This::Status
3163 got_prel(unsigned char *view,
3164 Arm_address got_entry,
3165 Arm_address address)
3167 Base::rel32(view, got_entry - address);
3168 return This::STATUS_OKAY;
3171 // R_ARM_PREL: (S + A) | T - P
3172 static inline typename This::Status
3173 prel31(unsigned char *view,
3174 const Sized_relobj<32, big_endian>* object,
3175 const Symbol_value<32>* psymval,
3176 Arm_address address,
3177 Arm_address thumb_bit)
3179 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3180 Valtype* wv = reinterpret_cast<Valtype*>(view);
3181 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3182 Valtype addend = utils::sign_extend<31>(val);
3183 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3184 val = utils::bit_select(val, x, 0x7fffffffU);
3185 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3186 return (utils::has_overflow<31>(x) ?
3187 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3190 // R_ARM_MOVW_ABS_NC: (S + A) | T (relative address base is )
3191 // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3192 // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3193 // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3194 static inline typename This::Status
3195 movw(unsigned char* view,
3196 const Sized_relobj<32, big_endian>* object,
3197 const Symbol_value<32>* psymval,
3198 Arm_address relative_address_base,
3199 Arm_address thumb_bit,
3200 bool check_overflow)
3202 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3203 Valtype* wv = reinterpret_cast<Valtype*>(view);
3204 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3205 Valtype addend = This::extract_arm_movw_movt_addend(val);
3206 Valtype x = ((psymval->value(object, addend) | thumb_bit)
3207 - relative_address_base);
3208 val = This::insert_val_arm_movw_movt(val, x);
3209 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3210 return ((check_overflow && utils::has_overflow<16>(x))
3211 ? This::STATUS_OVERFLOW
3212 : This::STATUS_OKAY);
3215 // R_ARM_MOVT_ABS: S + A (relative address base is 0)
3216 // R_ARM_MOVT_PREL: S + A - P
3217 // R_ARM_MOVT_BREL: S + A - B(S)
3218 static inline typename This::Status
3219 movt(unsigned char* view,
3220 const Sized_relobj<32, big_endian>* object,
3221 const Symbol_value<32>* psymval,
3222 Arm_address relative_address_base)
3224 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3225 Valtype* wv = reinterpret_cast<Valtype*>(view);
3226 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3227 Valtype addend = This::extract_arm_movw_movt_addend(val);
3228 Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3229 val = This::insert_val_arm_movw_movt(val, x);
3230 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3231 // FIXME: IHI0044D says that we should check for overflow.
3232 return This::STATUS_OKAY;
3235 // R_ARM_THM_MOVW_ABS_NC: S + A | T (relative_address_base is 0)
3236 // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3237 // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3238 // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3239 static inline typename This::Status
3240 thm_movw(unsigned char *view,
3241 const Sized_relobj<32, big_endian>* object,
3242 const Symbol_value<32>* psymval,
3243 Arm_address relative_address_base,
3244 Arm_address thumb_bit,
3245 bool check_overflow)
3247 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3248 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3249 Valtype* wv = reinterpret_cast<Valtype*>(view);
3250 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3251 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3252 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3253 Reltype x =
3254 (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3255 val = This::insert_val_thumb_movw_movt(val, x);
3256 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3257 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3258 return ((check_overflow && utils::has_overflow<16>(x))
3259 ? This::STATUS_OVERFLOW
3260 : This::STATUS_OKAY);
3263 // R_ARM_THM_MOVT_ABS: S + A (relative address base is 0)
3264 // R_ARM_THM_MOVT_PREL: S + A - P
3265 // R_ARM_THM_MOVT_BREL: S + A - B(S)
3266 static inline typename This::Status
3267 thm_movt(unsigned char* view,
3268 const Sized_relobj<32, big_endian>* object,
3269 const Symbol_value<32>* psymval,
3270 Arm_address relative_address_base)
3272 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3273 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3274 Valtype* wv = reinterpret_cast<Valtype*>(view);
3275 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3276 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3277 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3278 Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3279 val = This::insert_val_thumb_movw_movt(val, x);
3280 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3281 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3282 return This::STATUS_OKAY;
3285 // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3286 static inline typename This::Status
3287 thm_alu11(unsigned char* view,
3288 const Sized_relobj<32, big_endian>* object,
3289 const Symbol_value<32>* psymval,
3290 Arm_address address,
3291 Arm_address thumb_bit)
3293 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3294 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3295 Valtype* wv = reinterpret_cast<Valtype*>(view);
3296 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3297 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3299 // f e d c b|a|9|8 7 6 5|4|3 2 1 0||f|e d c|b a 9 8|7 6 5 4 3 2 1 0
3300 // -----------------------------------------------------------------------
3301 // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd |imm8
3302 // ADDW 1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd |imm8
3303 // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd |imm8
3304 // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd |imm8
3305 // SUBW 1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd |imm8
3306 // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd |imm8
3308 // Determine a sign for the addend.
3309 const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3310 || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3311 // Thumb2 addend encoding:
3312 // imm12 := i | imm3 | imm8
3313 int32_t addend = (insn & 0xff)
3314 | ((insn & 0x00007000) >> 4)
3315 | ((insn & 0x04000000) >> 15);
3316 // Apply a sign to the added.
3317 addend *= sign;
3319 int32_t x = (psymval->value(object, addend) | thumb_bit)
3320 - (address & 0xfffffffc);
3321 Reltype val = abs(x);
3322 // Mask out the value and a distinct part of the ADD/SUB opcode
3323 // (bits 7:5 of opword).
3324 insn = (insn & 0xfb0f8f00)
3325 | (val & 0xff)
3326 | ((val & 0x700) << 4)
3327 | ((val & 0x800) << 15);
3328 // Set the opcode according to whether the value to go in the
3329 // place is negative.
3330 if (x < 0)
3331 insn |= 0x00a00000;
3333 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3334 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3335 return ((val > 0xfff) ?
3336 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3339 // R_ARM_THM_PC8: S + A - Pa (Thumb)
3340 static inline typename This::Status
3341 thm_pc8(unsigned char* view,
3342 const Sized_relobj<32, big_endian>* object,
3343 const Symbol_value<32>* psymval,
3344 Arm_address address)
3346 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3347 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3348 Valtype* wv = reinterpret_cast<Valtype*>(view);
3349 Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3350 Reltype addend = ((insn & 0x00ff) << 2);
3351 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3352 Reltype val = abs(x);
3353 insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3355 elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3356 return ((val > 0x03fc)
3357 ? This::STATUS_OVERFLOW
3358 : This::STATUS_OKAY);
3361 // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3362 static inline typename This::Status
3363 thm_pc12(unsigned char* view,
3364 const Sized_relobj<32, big_endian>* object,
3365 const Symbol_value<32>* psymval,
3366 Arm_address address)
3368 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3369 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3370 Valtype* wv = reinterpret_cast<Valtype*>(view);
3371 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3372 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3373 // Determine a sign for the addend (positive if the U bit is 1).
3374 const int sign = (insn & 0x00800000) ? 1 : -1;
3375 int32_t addend = (insn & 0xfff);
3376 // Apply a sign to the added.
3377 addend *= sign;
3379 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3380 Reltype val = abs(x);
3381 // Mask out and apply the value and the U bit.
3382 insn = (insn & 0xff7ff000) | (val & 0xfff);
3383 // Set the U bit according to whether the value to go in the
3384 // place is positive.
3385 if (x >= 0)
3386 insn |= 0x00800000;
3388 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3389 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3390 return ((val > 0xfff) ?
3391 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3394 // R_ARM_V4BX
3395 static inline typename This::Status
3396 v4bx(const Relocate_info<32, big_endian>* relinfo,
3397 unsigned char *view,
3398 const Arm_relobj<big_endian>* object,
3399 const Arm_address address,
3400 const bool is_interworking)
3403 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3404 Valtype* wv = reinterpret_cast<Valtype*>(view);
3405 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3407 // Ensure that we have a BX instruction.
3408 gold_assert((val & 0x0ffffff0) == 0x012fff10);
3409 const uint32_t reg = (val & 0xf);
3410 if (is_interworking && reg != 0xf)
3412 Stub_table<big_endian>* stub_table =
3413 object->stub_table(relinfo->data_shndx);
3414 gold_assert(stub_table != NULL);
3416 Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3417 gold_assert(stub != NULL);
3419 int32_t veneer_address =
3420 stub_table->address() + stub->offset() - 8 - address;
3421 gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3422 && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3423 // Replace with a branch to veneer (B <addr>)
3424 val = (val & 0xf0000000) | 0x0a000000
3425 | ((veneer_address >> 2) & 0x00ffffff);
3427 else
3429 // Preserve Rm (lowest four bits) and the condition code
3430 // (highest four bits). Other bits encode MOV PC,Rm.
3431 val = (val & 0xf000000f) | 0x01a0f000;
3433 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3434 return This::STATUS_OKAY;
3437 // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3438 // R_ARM_ALU_PC_G0: ((S + A) | T) - P
3439 // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3440 // R_ARM_ALU_PC_G1: ((S + A) | T) - P
3441 // R_ARM_ALU_PC_G2: ((S + A) | T) - P
3442 // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3443 // R_ARM_ALU_SB_G0: ((S + A) | T) - B(S)
3444 // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3445 // R_ARM_ALU_SB_G1: ((S + A) | T) - B(S)
3446 // R_ARM_ALU_SB_G2: ((S + A) | T) - B(S)
3447 static inline typename This::Status
3448 arm_grp_alu(unsigned char* view,
3449 const Sized_relobj<32, big_endian>* object,
3450 const Symbol_value<32>* psymval,
3451 const int group,
3452 Arm_address address,
3453 Arm_address thumb_bit,
3454 bool check_overflow)
3456 gold_assert(group >= 0 && group < 3);
3457 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3458 Valtype* wv = reinterpret_cast<Valtype*>(view);
3459 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3461 // ALU group relocations are allowed only for the ADD/SUB instructions.
3462 // (0x00800000 - ADD, 0x00400000 - SUB)
3463 const Valtype opcode = insn & 0x01e00000;
3464 if (opcode != 0x00800000 && opcode != 0x00400000)
3465 return This::STATUS_BAD_RELOC;
3467 // Determine a sign for the addend.
3468 const int sign = (opcode == 0x00800000) ? 1 : -1;
3469 // shifter = rotate_imm * 2
3470 const uint32_t shifter = (insn & 0xf00) >> 7;
3471 // Initial addend value.
3472 int32_t addend = insn & 0xff;
3473 // Rotate addend right by shifter.
3474 addend = (addend >> shifter) | (addend << (32 - shifter));
3475 // Apply a sign to the added.
3476 addend *= sign;
3478 int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3479 Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3480 // Check for overflow if required
3481 if (check_overflow
3482 && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3483 return This::STATUS_OVERFLOW;
3485 // Mask out the value and the ADD/SUB part of the opcode; take care
3486 // not to destroy the S bit.
3487 insn &= 0xff1ff000;
3488 // Set the opcode according to whether the value to go in the
3489 // place is negative.
3490 insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3491 // Encode the offset (encoded Gn).
3492 insn |= gn;
3494 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3495 return This::STATUS_OKAY;
3498 // R_ARM_LDR_PC_G0: S + A - P
3499 // R_ARM_LDR_PC_G1: S + A - P
3500 // R_ARM_LDR_PC_G2: S + A - P
3501 // R_ARM_LDR_SB_G0: S + A - B(S)
3502 // R_ARM_LDR_SB_G1: S + A - B(S)
3503 // R_ARM_LDR_SB_G2: S + A - B(S)
3504 static inline typename This::Status
3505 arm_grp_ldr(unsigned char* view,
3506 const Sized_relobj<32, big_endian>* object,
3507 const Symbol_value<32>* psymval,
3508 const int group,
3509 Arm_address address)
3511 gold_assert(group >= 0 && group < 3);
3512 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3513 Valtype* wv = reinterpret_cast<Valtype*>(view);
3514 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3516 const int sign = (insn & 0x00800000) ? 1 : -1;
3517 int32_t addend = (insn & 0xfff) * sign;
3518 int32_t x = (psymval->value(object, addend) - address);
3519 // Calculate the relevant G(n-1) value to obtain this stage residual.
3520 Valtype residual =
3521 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3522 if (residual >= 0x1000)
3523 return This::STATUS_OVERFLOW;
3525 // Mask out the value and U bit.
3526 insn &= 0xff7ff000;
3527 // Set the U bit for non-negative values.
3528 if (x >= 0)
3529 insn |= 0x00800000;
3530 insn |= residual;
3532 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3533 return This::STATUS_OKAY;
3536 // R_ARM_LDRS_PC_G0: S + A - P
3537 // R_ARM_LDRS_PC_G1: S + A - P
3538 // R_ARM_LDRS_PC_G2: S + A - P
3539 // R_ARM_LDRS_SB_G0: S + A - B(S)
3540 // R_ARM_LDRS_SB_G1: S + A - B(S)
3541 // R_ARM_LDRS_SB_G2: S + A - B(S)
3542 static inline typename This::Status
3543 arm_grp_ldrs(unsigned char* view,
3544 const Sized_relobj<32, big_endian>* object,
3545 const Symbol_value<32>* psymval,
3546 const int group,
3547 Arm_address address)
3549 gold_assert(group >= 0 && group < 3);
3550 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3551 Valtype* wv = reinterpret_cast<Valtype*>(view);
3552 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3554 const int sign = (insn & 0x00800000) ? 1 : -1;
3555 int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3556 int32_t x = (psymval->value(object, addend) - address);
3557 // Calculate the relevant G(n-1) value to obtain this stage residual.
3558 Valtype residual =
3559 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3560 if (residual >= 0x100)
3561 return This::STATUS_OVERFLOW;
3563 // Mask out the value and U bit.
3564 insn &= 0xff7ff0f0;
3565 // Set the U bit for non-negative values.
3566 if (x >= 0)
3567 insn |= 0x00800000;
3568 insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3570 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3571 return This::STATUS_OKAY;
3574 // R_ARM_LDC_PC_G0: S + A - P
3575 // R_ARM_LDC_PC_G1: S + A - P
3576 // R_ARM_LDC_PC_G2: S + A - P
3577 // R_ARM_LDC_SB_G0: S + A - B(S)
3578 // R_ARM_LDC_SB_G1: S + A - B(S)
3579 // R_ARM_LDC_SB_G2: S + A - B(S)
3580 static inline typename This::Status
3581 arm_grp_ldc(unsigned char* view,
3582 const Sized_relobj<32, big_endian>* object,
3583 const Symbol_value<32>* psymval,
3584 const int group,
3585 Arm_address address)
3587 gold_assert(group >= 0 && group < 3);
3588 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3589 Valtype* wv = reinterpret_cast<Valtype*>(view);
3590 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3592 const int sign = (insn & 0x00800000) ? 1 : -1;
3593 int32_t addend = ((insn & 0xff) << 2) * sign;
3594 int32_t x = (psymval->value(object, addend) - address);
3595 // Calculate the relevant G(n-1) value to obtain this stage residual.
3596 Valtype residual =
3597 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3598 if ((residual & 0x3) != 0 || residual >= 0x400)
3599 return This::STATUS_OVERFLOW;
3601 // Mask out the value and U bit.
3602 insn &= 0xff7fff00;
3603 // Set the U bit for non-negative values.
3604 if (x >= 0)
3605 insn |= 0x00800000;
3606 insn |= (residual >> 2);
3608 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3609 return This::STATUS_OKAY;
3613 // Relocate ARM long branches. This handles relocation types
3614 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3615 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3616 // undefined and we do not use PLT in this relocation. In such a case,
3617 // the branch is converted into an NOP.
3619 template<bool big_endian>
3620 typename Arm_relocate_functions<big_endian>::Status
3621 Arm_relocate_functions<big_endian>::arm_branch_common(
3622 unsigned int r_type,
3623 const Relocate_info<32, big_endian>* relinfo,
3624 unsigned char *view,
3625 const Sized_symbol<32>* gsym,
3626 const Arm_relobj<big_endian>* object,
3627 unsigned int r_sym,
3628 const Symbol_value<32>* psymval,
3629 Arm_address address,
3630 Arm_address thumb_bit,
3631 bool is_weakly_undefined_without_plt)
3633 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3634 Valtype* wv = reinterpret_cast<Valtype*>(view);
3635 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3637 bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3638 && ((val & 0x0f000000UL) == 0x0a000000UL);
3639 bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3640 bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3641 && ((val & 0x0f000000UL) == 0x0b000000UL);
3642 bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3643 bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3645 // Check that the instruction is valid.
3646 if (r_type == elfcpp::R_ARM_CALL)
3648 if (!insn_is_uncond_bl && !insn_is_blx)
3649 return This::STATUS_BAD_RELOC;
3651 else if (r_type == elfcpp::R_ARM_JUMP24)
3653 if (!insn_is_b && !insn_is_cond_bl)
3654 return This::STATUS_BAD_RELOC;
3656 else if (r_type == elfcpp::R_ARM_PLT32)
3658 if (!insn_is_any_branch)
3659 return This::STATUS_BAD_RELOC;
3661 else if (r_type == elfcpp::R_ARM_XPC25)
3663 // FIXME: AAELF document IH0044C does not say much about it other
3664 // than it being obsolete.
3665 if (!insn_is_any_branch)
3666 return This::STATUS_BAD_RELOC;
3668 else
3669 gold_unreachable();
3671 // A branch to an undefined weak symbol is turned into a jump to
3672 // the next instruction unless a PLT entry will be created.
3673 // Do the same for local undefined symbols.
3674 // The jump to the next instruction is optimized as a NOP depending
3675 // on the architecture.
3676 const Target_arm<big_endian>* arm_target =
3677 Target_arm<big_endian>::default_target();
3678 if (is_weakly_undefined_without_plt)
3680 Valtype cond = val & 0xf0000000U;
3681 if (arm_target->may_use_arm_nop())
3682 val = cond | 0x0320f000;
3683 else
3684 val = cond | 0x01a00000; // Using pre-UAL nop: mov r0, r0.
3685 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3686 return This::STATUS_OKAY;
3689 Valtype addend = utils::sign_extend<26>(val << 2);
3690 Valtype branch_target = psymval->value(object, addend);
3691 int32_t branch_offset = branch_target - address;
3693 // We need a stub if the branch offset is too large or if we need
3694 // to switch mode.
3695 bool may_use_blx = arm_target->may_use_blx();
3696 Reloc_stub* stub = NULL;
3697 if (utils::has_overflow<26>(branch_offset)
3698 || ((thumb_bit != 0) && !(may_use_blx && r_type == elfcpp::R_ARM_CALL)))
3700 Valtype unadjusted_branch_target = psymval->value(object, 0);
3702 Stub_type stub_type =
3703 Reloc_stub::stub_type_for_reloc(r_type, address,
3704 unadjusted_branch_target,
3705 (thumb_bit != 0));
3706 if (stub_type != arm_stub_none)
3708 Stub_table<big_endian>* stub_table =
3709 object->stub_table(relinfo->data_shndx);
3710 gold_assert(stub_table != NULL);
3712 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3713 stub = stub_table->find_reloc_stub(stub_key);
3714 gold_assert(stub != NULL);
3715 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3716 branch_target = stub_table->address() + stub->offset() + addend;
3717 branch_offset = branch_target - address;
3718 gold_assert(!utils::has_overflow<26>(branch_offset));
3722 // At this point, if we still need to switch mode, the instruction
3723 // must either be a BLX or a BL that can be converted to a BLX.
3724 if (thumb_bit != 0)
3726 // Turn BL to BLX.
3727 gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3728 val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3731 val = utils::bit_select(val, (branch_offset >> 2), 0xffffffUL);
3732 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3733 return (utils::has_overflow<26>(branch_offset)
3734 ? This::STATUS_OVERFLOW : This::STATUS_OKAY);
3737 // Relocate THUMB long branches. This handles relocation types
3738 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3739 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3740 // undefined and we do not use PLT in this relocation. In such a case,
3741 // the branch is converted into an NOP.
3743 template<bool big_endian>
3744 typename Arm_relocate_functions<big_endian>::Status
3745 Arm_relocate_functions<big_endian>::thumb_branch_common(
3746 unsigned int r_type,
3747 const Relocate_info<32, big_endian>* relinfo,
3748 unsigned char *view,
3749 const Sized_symbol<32>* gsym,
3750 const Arm_relobj<big_endian>* object,
3751 unsigned int r_sym,
3752 const Symbol_value<32>* psymval,
3753 Arm_address address,
3754 Arm_address thumb_bit,
3755 bool is_weakly_undefined_without_plt)
3757 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3758 Valtype* wv = reinterpret_cast<Valtype*>(view);
3759 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
3760 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
3762 // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
3763 // into account.
3764 bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
3765 bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
3767 // Check that the instruction is valid.
3768 if (r_type == elfcpp::R_ARM_THM_CALL)
3770 if (!is_bl_insn && !is_blx_insn)
3771 return This::STATUS_BAD_RELOC;
3773 else if (r_type == elfcpp::R_ARM_THM_JUMP24)
3775 // This cannot be a BLX.
3776 if (!is_bl_insn)
3777 return This::STATUS_BAD_RELOC;
3779 else if (r_type == elfcpp::R_ARM_THM_XPC22)
3781 // Check for Thumb to Thumb call.
3782 if (!is_blx_insn)
3783 return This::STATUS_BAD_RELOC;
3784 if (thumb_bit != 0)
3786 gold_warning(_("%s: Thumb BLX instruction targets "
3787 "thumb function '%s'."),
3788 object->name().c_str(),
3789 (gsym ? gsym->name() : "(local)"));
3790 // Convert BLX to BL.
3791 lower_insn |= 0x1000U;
3794 else
3795 gold_unreachable();
3797 // A branch to an undefined weak symbol is turned into a jump to
3798 // the next instruction unless a PLT entry will be created.
3799 // The jump to the next instruction is optimized as a NOP.W for
3800 // Thumb-2 enabled architectures.
3801 const Target_arm<big_endian>* arm_target =
3802 Target_arm<big_endian>::default_target();
3803 if (is_weakly_undefined_without_plt)
3805 if (arm_target->may_use_thumb2_nop())
3807 elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
3808 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
3810 else
3812 elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
3813 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
3815 return This::STATUS_OKAY;
3818 int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
3819 Arm_address branch_target = psymval->value(object, addend);
3820 int32_t branch_offset = branch_target - address;
3822 // We need a stub if the branch offset is too large or if we need
3823 // to switch mode.
3824 bool may_use_blx = arm_target->may_use_blx();
3825 bool thumb2 = arm_target->using_thumb2();
3826 if ((!thumb2 && utils::has_overflow<23>(branch_offset))
3827 || (thumb2 && utils::has_overflow<25>(branch_offset))
3828 || ((thumb_bit == 0)
3829 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
3830 || r_type == elfcpp::R_ARM_THM_JUMP24)))
3832 Arm_address unadjusted_branch_target = psymval->value(object, 0);
3834 Stub_type stub_type =
3835 Reloc_stub::stub_type_for_reloc(r_type, address,
3836 unadjusted_branch_target,
3837 (thumb_bit != 0));
3839 if (stub_type != arm_stub_none)
3841 Stub_table<big_endian>* stub_table =
3842 object->stub_table(relinfo->data_shndx);
3843 gold_assert(stub_table != NULL);
3845 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3846 Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
3847 gold_assert(stub != NULL);
3848 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3849 branch_target = stub_table->address() + stub->offset() + addend;
3850 branch_offset = branch_target - address;
3854 // At this point, if we still need to switch mode, the instruction
3855 // must either be a BLX or a BL that can be converted to a BLX.
3856 if (thumb_bit == 0)
3858 gold_assert(may_use_blx
3859 && (r_type == elfcpp::R_ARM_THM_CALL
3860 || r_type == elfcpp::R_ARM_THM_XPC22));
3861 // Make sure this is a BLX.
3862 lower_insn &= ~0x1000U;
3864 else
3866 // Make sure this is a BL.
3867 lower_insn |= 0x1000U;
3870 if ((lower_insn & 0x5000U) == 0x4000U)
3871 // For a BLX instruction, make sure that the relocation is rounded up
3872 // to a word boundary. This follows the semantics of the instruction
3873 // which specifies that bit 1 of the target address will come from bit
3874 // 1 of the base address.
3875 branch_offset = (branch_offset + 2) & ~3;
3877 // Put BRANCH_OFFSET back into the insn. Assumes two's complement.
3878 // We use the Thumb-2 encoding, which is safe even if dealing with
3879 // a Thumb-1 instruction by virtue of our overflow check above. */
3880 upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
3881 lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
3883 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
3884 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
3886 return ((thumb2
3887 ? utils::has_overflow<25>(branch_offset)
3888 : utils::has_overflow<23>(branch_offset))
3889 ? This::STATUS_OVERFLOW
3890 : This::STATUS_OKAY);
3893 // Relocate THUMB-2 long conditional branches.
3894 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3895 // undefined and we do not use PLT in this relocation. In such a case,
3896 // the branch is converted into an NOP.
3898 template<bool big_endian>
3899 typename Arm_relocate_functions<big_endian>::Status
3900 Arm_relocate_functions<big_endian>::thm_jump19(
3901 unsigned char *view,
3902 const Arm_relobj<big_endian>* object,
3903 const Symbol_value<32>* psymval,
3904 Arm_address address,
3905 Arm_address thumb_bit)
3907 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3908 Valtype* wv = reinterpret_cast<Valtype*>(view);
3909 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
3910 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
3911 int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
3913 Arm_address branch_target = psymval->value(object, addend);
3914 int32_t branch_offset = branch_target - address;
3916 // ??? Should handle interworking? GCC might someday try to
3917 // use this for tail calls.
3918 // FIXME: We do support thumb entry to PLT yet.
3919 if (thumb_bit == 0)
3921 gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
3922 return This::STATUS_BAD_RELOC;
3925 // Put RELOCATION back into the insn.
3926 upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
3927 lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
3929 // Put the relocated value back in the object file:
3930 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
3931 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
3933 return (utils::has_overflow<21>(branch_offset)
3934 ? This::STATUS_OVERFLOW
3935 : This::STATUS_OKAY);
3938 // Get the GOT section, creating it if necessary.
3940 template<bool big_endian>
3941 Arm_output_data_got<big_endian>*
3942 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
3944 if (this->got_ == NULL)
3946 gold_assert(symtab != NULL && layout != NULL);
3948 this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
3950 Output_section* os;
3951 os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
3952 (elfcpp::SHF_ALLOC
3953 | elfcpp::SHF_WRITE),
3954 this->got_, false, false, false,
3955 true);
3956 // The old GNU linker creates a .got.plt section. We just
3957 // create another set of data in the .got section. Note that we
3958 // always create a PLT if we create a GOT, although the PLT
3959 // might be empty.
3960 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
3961 os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
3962 (elfcpp::SHF_ALLOC
3963 | elfcpp::SHF_WRITE),
3964 this->got_plt_, false, false,
3965 false, false);
3967 // The first three entries are reserved.
3968 this->got_plt_->set_current_data_size(3 * 4);
3970 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
3971 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
3972 Symbol_table::PREDEFINED,
3973 this->got_plt_,
3974 0, 0, elfcpp::STT_OBJECT,
3975 elfcpp::STB_LOCAL,
3976 elfcpp::STV_HIDDEN, 0,
3977 false, false);
3979 return this->got_;
3982 // Get the dynamic reloc section, creating it if necessary.
3984 template<bool big_endian>
3985 typename Target_arm<big_endian>::Reloc_section*
3986 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
3988 if (this->rel_dyn_ == NULL)
3990 gold_assert(layout != NULL);
3991 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
3992 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
3993 elfcpp::SHF_ALLOC, this->rel_dyn_, true,
3994 false, false, false);
3996 return this->rel_dyn_;
3999 // Insn_template methods.
4001 // Return byte size of an instruction template.
4003 size_t
4004 Insn_template::size() const
4006 switch (this->type())
4008 case THUMB16_TYPE:
4009 case THUMB16_SPECIAL_TYPE:
4010 return 2;
4011 case ARM_TYPE:
4012 case THUMB32_TYPE:
4013 case DATA_TYPE:
4014 return 4;
4015 default:
4016 gold_unreachable();
4020 // Return alignment of an instruction template.
4022 unsigned
4023 Insn_template::alignment() const
4025 switch (this->type())
4027 case THUMB16_TYPE:
4028 case THUMB16_SPECIAL_TYPE:
4029 case THUMB32_TYPE:
4030 return 2;
4031 case ARM_TYPE:
4032 case DATA_TYPE:
4033 return 4;
4034 default:
4035 gold_unreachable();
4039 // Stub_template methods.
4041 Stub_template::Stub_template(
4042 Stub_type type, const Insn_template* insns,
4043 size_t insn_count)
4044 : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4045 entry_in_thumb_mode_(false), relocs_()
4047 off_t offset = 0;
4049 // Compute byte size and alignment of stub template.
4050 for (size_t i = 0; i < insn_count; i++)
4052 unsigned insn_alignment = insns[i].alignment();
4053 size_t insn_size = insns[i].size();
4054 gold_assert((offset & (insn_alignment - 1)) == 0);
4055 this->alignment_ = std::max(this->alignment_, insn_alignment);
4056 switch (insns[i].type())
4058 case Insn_template::THUMB16_TYPE:
4059 case Insn_template::THUMB16_SPECIAL_TYPE:
4060 if (i == 0)
4061 this->entry_in_thumb_mode_ = true;
4062 break;
4064 case Insn_template::THUMB32_TYPE:
4065 if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4066 this->relocs_.push_back(Reloc(i, offset));
4067 if (i == 0)
4068 this->entry_in_thumb_mode_ = true;
4069 break;
4071 case Insn_template::ARM_TYPE:
4072 // Handle cases where the target is encoded within the
4073 // instruction.
4074 if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4075 this->relocs_.push_back(Reloc(i, offset));
4076 break;
4078 case Insn_template::DATA_TYPE:
4079 // Entry point cannot be data.
4080 gold_assert(i != 0);
4081 this->relocs_.push_back(Reloc(i, offset));
4082 break;
4084 default:
4085 gold_unreachable();
4087 offset += insn_size;
4089 this->size_ = offset;
4092 // Stub methods.
4094 // Template to implement do_write for a specific target endianity.
4096 template<bool big_endian>
4097 void inline
4098 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4100 const Stub_template* stub_template = this->stub_template();
4101 const Insn_template* insns = stub_template->insns();
4103 // FIXME: We do not handle BE8 encoding yet.
4104 unsigned char* pov = view;
4105 for (size_t i = 0; i < stub_template->insn_count(); i++)
4107 switch (insns[i].type())
4109 case Insn_template::THUMB16_TYPE:
4110 elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4111 break;
4112 case Insn_template::THUMB16_SPECIAL_TYPE:
4113 elfcpp::Swap<16, big_endian>::writeval(
4114 pov,
4115 this->thumb16_special(i));
4116 break;
4117 case Insn_template::THUMB32_TYPE:
4119 uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4120 uint32_t lo = insns[i].data() & 0xffff;
4121 elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4122 elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4124 break;
4125 case Insn_template::ARM_TYPE:
4126 case Insn_template::DATA_TYPE:
4127 elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4128 break;
4129 default:
4130 gold_unreachable();
4132 pov += insns[i].size();
4134 gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4137 // Reloc_stub::Key methods.
4139 // Dump a Key as a string for debugging.
4141 std::string
4142 Reloc_stub::Key::name() const
4144 if (this->r_sym_ == invalid_index)
4146 // Global symbol key name
4147 // <stub-type>:<symbol name>:<addend>.
4148 const std::string sym_name = this->u_.symbol->name();
4149 // We need to print two hex number and two colons. So just add 100 bytes
4150 // to the symbol name size.
4151 size_t len = sym_name.size() + 100;
4152 char* buffer = new char[len];
4153 int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4154 sym_name.c_str(), this->addend_);
4155 gold_assert(c > 0 && c < static_cast<int>(len));
4156 delete[] buffer;
4157 return std::string(buffer);
4159 else
4161 // local symbol key name
4162 // <stub-type>:<object>:<r_sym>:<addend>.
4163 const size_t len = 200;
4164 char buffer[len];
4165 int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4166 this->u_.relobj, this->r_sym_, this->addend_);
4167 gold_assert(c > 0 && c < static_cast<int>(len));
4168 return std::string(buffer);
4172 // Reloc_stub methods.
4174 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4175 // LOCATION to DESTINATION.
4176 // This code is based on the arm_type_of_stub function in
4177 // bfd/elf32-arm.c. We have changed the interface a liitle to keep the Stub
4178 // class simple.
4180 Stub_type
4181 Reloc_stub::stub_type_for_reloc(
4182 unsigned int r_type,
4183 Arm_address location,
4184 Arm_address destination,
4185 bool target_is_thumb)
4187 Stub_type stub_type = arm_stub_none;
4189 // This is a bit ugly but we want to avoid using a templated class for
4190 // big and little endianities.
4191 bool may_use_blx;
4192 bool should_force_pic_veneer;
4193 bool thumb2;
4194 bool thumb_only;
4195 if (parameters->target().is_big_endian())
4197 const Target_arm<true>* big_endian_target =
4198 Target_arm<true>::default_target();
4199 may_use_blx = big_endian_target->may_use_blx();
4200 should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4201 thumb2 = big_endian_target->using_thumb2();
4202 thumb_only = big_endian_target->using_thumb_only();
4204 else
4206 const Target_arm<false>* little_endian_target =
4207 Target_arm<false>::default_target();
4208 may_use_blx = little_endian_target->may_use_blx();
4209 should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4210 thumb2 = little_endian_target->using_thumb2();
4211 thumb_only = little_endian_target->using_thumb_only();
4214 int64_t branch_offset = (int64_t)destination - location;
4216 if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4218 // Handle cases where:
4219 // - this call goes too far (different Thumb/Thumb2 max
4220 // distance)
4221 // - it's a Thumb->Arm call and blx is not available, or it's a
4222 // Thumb->Arm branch (not bl). A stub is needed in this case.
4223 if ((!thumb2
4224 && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4225 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4226 || (thumb2
4227 && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4228 || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4229 || ((!target_is_thumb)
4230 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4231 || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4233 if (target_is_thumb)
4235 // Thumb to thumb.
4236 if (!thumb_only)
4238 stub_type = (parameters->options().shared()
4239 || should_force_pic_veneer)
4240 // PIC stubs.
4241 ? ((may_use_blx
4242 && (r_type == elfcpp::R_ARM_THM_CALL))
4243 // V5T and above. Stub starts with ARM code, so
4244 // we must be able to switch mode before
4245 // reaching it, which is only possible for 'bl'
4246 // (ie R_ARM_THM_CALL relocation).
4247 ? arm_stub_long_branch_any_thumb_pic
4248 // On V4T, use Thumb code only.
4249 : arm_stub_long_branch_v4t_thumb_thumb_pic)
4251 // non-PIC stubs.
4252 : ((may_use_blx
4253 && (r_type == elfcpp::R_ARM_THM_CALL))
4254 ? arm_stub_long_branch_any_any // V5T and above.
4255 : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4257 else
4259 stub_type = (parameters->options().shared()
4260 || should_force_pic_veneer)
4261 ? arm_stub_long_branch_thumb_only_pic // PIC stub.
4262 : arm_stub_long_branch_thumb_only; // non-PIC stub.
4265 else
4267 // Thumb to arm.
4269 // FIXME: We should check that the input section is from an
4270 // object that has interwork enabled.
4272 stub_type = (parameters->options().shared()
4273 || should_force_pic_veneer)
4274 // PIC stubs.
4275 ? ((may_use_blx
4276 && (r_type == elfcpp::R_ARM_THM_CALL))
4277 ? arm_stub_long_branch_any_arm_pic // V5T and above.
4278 : arm_stub_long_branch_v4t_thumb_arm_pic) // V4T.
4280 // non-PIC stubs.
4281 : ((may_use_blx
4282 && (r_type == elfcpp::R_ARM_THM_CALL))
4283 ? arm_stub_long_branch_any_any // V5T and above.
4284 : arm_stub_long_branch_v4t_thumb_arm); // V4T.
4286 // Handle v4t short branches.
4287 if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4288 && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4289 && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4290 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4294 else if (r_type == elfcpp::R_ARM_CALL
4295 || r_type == elfcpp::R_ARM_JUMP24
4296 || r_type == elfcpp::R_ARM_PLT32)
4298 if (target_is_thumb)
4300 // Arm to thumb.
4302 // FIXME: We should check that the input section is from an
4303 // object that has interwork enabled.
4305 // We have an extra 2-bytes reach because of
4306 // the mode change (bit 24 (H) of BLX encoding).
4307 if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4308 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4309 || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4310 || (r_type == elfcpp::R_ARM_JUMP24)
4311 || (r_type == elfcpp::R_ARM_PLT32))
4313 stub_type = (parameters->options().shared()
4314 || should_force_pic_veneer)
4315 // PIC stubs.
4316 ? (may_use_blx
4317 ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4318 : arm_stub_long_branch_v4t_arm_thumb_pic) // V4T stub.
4320 // non-PIC stubs.
4321 : (may_use_blx
4322 ? arm_stub_long_branch_any_any // V5T and above.
4323 : arm_stub_long_branch_v4t_arm_thumb); // V4T.
4326 else
4328 // Arm to arm.
4329 if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4330 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4332 stub_type = (parameters->options().shared()
4333 || should_force_pic_veneer)
4334 ? arm_stub_long_branch_any_arm_pic // PIC stubs.
4335 : arm_stub_long_branch_any_any; /// non-PIC.
4340 return stub_type;
4343 // Cortex_a8_stub methods.
4345 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4346 // I is the position of the instruction template in the stub template.
4348 uint16_t
4349 Cortex_a8_stub::do_thumb16_special(size_t i)
4351 // The only use of this is to copy condition code from a conditional
4352 // branch being worked around to the corresponding conditional branch in
4353 // to the stub.
4354 gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4355 && i == 0);
4356 uint16_t data = this->stub_template()->insns()[i].data();
4357 gold_assert((data & 0xff00U) == 0xd000U);
4358 data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4359 return data;
4362 // Stub_factory methods.
4364 Stub_factory::Stub_factory()
4366 // The instruction template sequences are declared as static
4367 // objects and initialized first time the constructor runs.
4369 // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4370 // to reach the stub if necessary.
4371 static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4373 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4374 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4375 // dcd R_ARM_ABS32(X)
4378 // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4379 // available.
4380 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4382 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4383 Insn_template::arm_insn(0xe12fff1c), // bx ip
4384 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4385 // dcd R_ARM_ABS32(X)
4388 // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4389 static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4391 Insn_template::thumb16_insn(0xb401), // push {r0}
4392 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4393 Insn_template::thumb16_insn(0x4684), // mov ip, r0
4394 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4395 Insn_template::thumb16_insn(0x4760), // bx ip
4396 Insn_template::thumb16_insn(0xbf00), // nop
4397 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4398 // dcd R_ARM_ABS32(X)
4401 // V4T Thumb -> Thumb long branch stub. Using the stack is not
4402 // allowed.
4403 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4405 Insn_template::thumb16_insn(0x4778), // bx pc
4406 Insn_template::thumb16_insn(0x46c0), // nop
4407 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4408 Insn_template::arm_insn(0xe12fff1c), // bx ip
4409 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4410 // dcd R_ARM_ABS32(X)
4413 // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4414 // available.
4415 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4417 Insn_template::thumb16_insn(0x4778), // bx pc
4418 Insn_template::thumb16_insn(0x46c0), // nop
4419 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4420 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4421 // dcd R_ARM_ABS32(X)
4424 // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4425 // one, when the destination is close enough.
4426 static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4428 Insn_template::thumb16_insn(0x4778), // bx pc
4429 Insn_template::thumb16_insn(0x46c0), // nop
4430 Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8)
4433 // ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use
4434 // blx to reach the stub if necessary.
4435 static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4437 Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc]
4438 Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip
4439 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4440 // dcd R_ARM_REL32(X-4)
4443 // ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use
4444 // blx to reach the stub if necessary. We can not add into pc;
4445 // it is not guaranteed to mode switch (different in ARMv6 and
4446 // ARMv7).
4447 static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4449 Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4]
4450 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4451 Insn_template::arm_insn(0xe12fff1c), // bx ip
4452 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4453 // dcd R_ARM_REL32(X)
4456 // V4T ARM -> ARM long branch stub, PIC.
4457 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4459 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4460 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4461 Insn_template::arm_insn(0xe12fff1c), // bx ip
4462 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4463 // dcd R_ARM_REL32(X)
4466 // V4T Thumb -> ARM long branch stub, PIC.
4467 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4469 Insn_template::thumb16_insn(0x4778), // bx pc
4470 Insn_template::thumb16_insn(0x46c0), // nop
4471 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4472 Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc
4473 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4474 // dcd R_ARM_REL32(X)
4477 // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4478 // architectures.
4479 static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4481 Insn_template::thumb16_insn(0xb401), // push {r0}
4482 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4483 Insn_template::thumb16_insn(0x46fc), // mov ip, pc
4484 Insn_template::thumb16_insn(0x4484), // add ip, r0
4485 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4486 Insn_template::thumb16_insn(0x4760), // bx ip
4487 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4488 // dcd R_ARM_REL32(X)
4491 // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4492 // allowed.
4493 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4495 Insn_template::thumb16_insn(0x4778), // bx pc
4496 Insn_template::thumb16_insn(0x46c0), // nop
4497 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4498 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4499 Insn_template::arm_insn(0xe12fff1c), // bx ip
4500 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4501 // dcd R_ARM_REL32(X)
4504 // Cortex-A8 erratum-workaround stubs.
4506 // Stub used for conditional branches (which may be beyond +/-1MB away,
4507 // so we can't use a conditional branch to reach this stub).
4509 // original code:
4511 // b<cond> X
4512 // after:
4514 static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4516 Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true
4517 Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after
4518 Insn_template::thumb32_b_insn(0xf000b800, -4) // true:
4519 // b.w X
4522 // Stub used for b.w and bl.w instructions.
4524 static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4526 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4529 static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4531 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4534 // Stub used for Thumb-2 blx.w instructions. We modified the original blx.w
4535 // instruction (which switches to ARM mode) to point to this stub. Jump to
4536 // the real destination using an ARM-mode branch.
4537 static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4539 Insn_template::arm_rel_insn(0xea000000, -8) // b dest
4542 // Stub used to provide an interworking for R_ARM_V4BX relocation
4543 // (bx r[n] instruction).
4544 static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4546 Insn_template::arm_insn(0xe3100001), // tst r<n>, #1
4547 Insn_template::arm_insn(0x01a0f000), // moveq pc, r<n>
4548 Insn_template::arm_insn(0xe12fff10) // bx r<n>
4551 // Fill in the stub template look-up table. Stub templates are constructed
4552 // per instance of Stub_factory for fast look-up without locking
4553 // in a thread-enabled environment.
4555 this->stub_templates_[arm_stub_none] =
4556 new Stub_template(arm_stub_none, NULL, 0);
4558 #define DEF_STUB(x) \
4559 do \
4561 size_t array_size \
4562 = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4563 Stub_type type = arm_stub_##x; \
4564 this->stub_templates_[type] = \
4565 new Stub_template(type, elf32_arm_stub_##x, array_size); \
4567 while (0);
4569 DEF_STUBS
4570 #undef DEF_STUB
4573 // Stub_table methods.
4575 // Removel all Cortex-A8 stub.
4577 template<bool big_endian>
4578 void
4579 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4581 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4582 p != this->cortex_a8_stubs_.end();
4583 ++p)
4584 delete p->second;
4585 this->cortex_a8_stubs_.clear();
4588 // Relocate one stub. This is a helper for Stub_table::relocate_stubs().
4590 template<bool big_endian>
4591 void
4592 Stub_table<big_endian>::relocate_stub(
4593 Stub* stub,
4594 const Relocate_info<32, big_endian>* relinfo,
4595 Target_arm<big_endian>* arm_target,
4596 Output_section* output_section,
4597 unsigned char* view,
4598 Arm_address address,
4599 section_size_type view_size)
4601 const Stub_template* stub_template = stub->stub_template();
4602 if (stub_template->reloc_count() != 0)
4604 // Adjust view to cover the stub only.
4605 section_size_type offset = stub->offset();
4606 section_size_type stub_size = stub_template->size();
4607 gold_assert(offset + stub_size <= view_size);
4609 arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4610 address + offset, stub_size);
4614 // Relocate all stubs in this stub table.
4616 template<bool big_endian>
4617 void
4618 Stub_table<big_endian>::relocate_stubs(
4619 const Relocate_info<32, big_endian>* relinfo,
4620 Target_arm<big_endian>* arm_target,
4621 Output_section* output_section,
4622 unsigned char* view,
4623 Arm_address address,
4624 section_size_type view_size)
4626 // If we are passed a view bigger than the stub table's. we need to
4627 // adjust the view.
4628 gold_assert(address == this->address()
4629 && (view_size
4630 == static_cast<section_size_type>(this->data_size())));
4632 // Relocate all relocation stubs.
4633 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4634 p != this->reloc_stubs_.end();
4635 ++p)
4636 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4637 address, view_size);
4639 // Relocate all Cortex-A8 stubs.
4640 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4641 p != this->cortex_a8_stubs_.end();
4642 ++p)
4643 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4644 address, view_size);
4646 // Relocate all ARM V4BX stubs.
4647 for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4648 p != this->arm_v4bx_stubs_.end();
4649 ++p)
4651 if (*p != NULL)
4652 this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4653 address, view_size);
4657 // Write out the stubs to file.
4659 template<bool big_endian>
4660 void
4661 Stub_table<big_endian>::do_write(Output_file* of)
4663 off_t offset = this->offset();
4664 const section_size_type oview_size =
4665 convert_to_section_size_type(this->data_size());
4666 unsigned char* const oview = of->get_output_view(offset, oview_size);
4668 // Write relocation stubs.
4669 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4670 p != this->reloc_stubs_.end();
4671 ++p)
4673 Reloc_stub* stub = p->second;
4674 Arm_address address = this->address() + stub->offset();
4675 gold_assert(address
4676 == align_address(address,
4677 stub->stub_template()->alignment()));
4678 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4679 big_endian);
4682 // Write Cortex-A8 stubs.
4683 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4684 p != this->cortex_a8_stubs_.end();
4685 ++p)
4687 Cortex_a8_stub* stub = p->second;
4688 Arm_address address = this->address() + stub->offset();
4689 gold_assert(address
4690 == align_address(address,
4691 stub->stub_template()->alignment()));
4692 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4693 big_endian);
4696 // Write ARM V4BX relocation stubs.
4697 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4698 p != this->arm_v4bx_stubs_.end();
4699 ++p)
4701 if (*p == NULL)
4702 continue;
4704 Arm_address address = this->address() + (*p)->offset();
4705 gold_assert(address
4706 == align_address(address,
4707 (*p)->stub_template()->alignment()));
4708 (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4709 big_endian);
4712 of->write_output_view(this->offset(), oview_size, oview);
4715 // Update the data size and address alignment of the stub table at the end
4716 // of a relaxation pass. Return true if either the data size or the
4717 // alignment changed in this relaxation pass.
4719 template<bool big_endian>
4720 bool
4721 Stub_table<big_endian>::update_data_size_and_addralign()
4723 off_t size = 0;
4724 unsigned addralign = 1;
4726 // Go over all stubs in table to compute data size and address alignment.
4728 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4729 p != this->reloc_stubs_.end();
4730 ++p)
4732 const Stub_template* stub_template = p->second->stub_template();
4733 addralign = std::max(addralign, stub_template->alignment());
4734 size = (align_address(size, stub_template->alignment())
4735 + stub_template->size());
4738 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4739 p != this->cortex_a8_stubs_.end();
4740 ++p)
4742 const Stub_template* stub_template = p->second->stub_template();
4743 addralign = std::max(addralign, stub_template->alignment());
4744 size = (align_address(size, stub_template->alignment())
4745 + stub_template->size());
4748 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4749 p != this->arm_v4bx_stubs_.end();
4750 ++p)
4752 if (*p == NULL)
4753 continue;
4755 const Stub_template* stub_template = (*p)->stub_template();
4756 addralign = std::max(addralign, stub_template->alignment());
4757 size = (align_address(size, stub_template->alignment())
4758 + stub_template->size());
4761 // Check if either data size or alignment changed in this pass.
4762 // Update prev_data_size_ and prev_addralign_. These will be used
4763 // as the current data size and address alignment for the next pass.
4764 bool changed = size != this->prev_data_size_;
4765 this->prev_data_size_ = size;
4767 if (addralign != this->prev_addralign_)
4768 changed = true;
4769 this->prev_addralign_ = addralign;
4771 return changed;
4774 // Finalize the stubs. This sets the offsets of the stubs within the stub
4775 // table. It also marks all input sections needing Cortex-A8 workaround.
4777 template<bool big_endian>
4778 void
4779 Stub_table<big_endian>::finalize_stubs()
4781 off_t off = 0;
4782 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4783 p != this->reloc_stubs_.end();
4784 ++p)
4786 Reloc_stub* stub = p->second;
4787 const Stub_template* stub_template = stub->stub_template();
4788 uint64_t stub_addralign = stub_template->alignment();
4789 off = align_address(off, stub_addralign);
4790 stub->set_offset(off);
4791 off += stub_template->size();
4794 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4795 p != this->cortex_a8_stubs_.end();
4796 ++p)
4798 Cortex_a8_stub* stub = p->second;
4799 const Stub_template* stub_template = stub->stub_template();
4800 uint64_t stub_addralign = stub_template->alignment();
4801 off = align_address(off, stub_addralign);
4802 stub->set_offset(off);
4803 off += stub_template->size();
4805 // Mark input section so that we can determine later if a code section
4806 // needs the Cortex-A8 workaround quickly.
4807 Arm_relobj<big_endian>* arm_relobj =
4808 Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
4809 arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
4812 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4813 p != this->arm_v4bx_stubs_.end();
4814 ++p)
4816 if (*p == NULL)
4817 continue;
4819 const Stub_template* stub_template = (*p)->stub_template();
4820 uint64_t stub_addralign = stub_template->alignment();
4821 off = align_address(off, stub_addralign);
4822 (*p)->set_offset(off);
4823 off += stub_template->size();
4826 gold_assert(off <= this->prev_data_size_);
4829 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
4830 // and VIEW_ADDRESS + VIEW_SIZE - 1. VIEW points to the mapped address
4831 // of the address range seen by the linker.
4833 template<bool big_endian>
4834 void
4835 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
4836 Target_arm<big_endian>* arm_target,
4837 unsigned char* view,
4838 Arm_address view_address,
4839 section_size_type view_size)
4841 // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
4842 for (Cortex_a8_stub_list::const_iterator p =
4843 this->cortex_a8_stubs_.lower_bound(view_address);
4844 ((p != this->cortex_a8_stubs_.end())
4845 && (p->first < (view_address + view_size)));
4846 ++p)
4848 // We do not store the THUMB bit in the LSB of either the branch address
4849 // or the stub offset. There is no need to strip the LSB.
4850 Arm_address branch_address = p->first;
4851 const Cortex_a8_stub* stub = p->second;
4852 Arm_address stub_address = this->address() + stub->offset();
4854 // Offset of the branch instruction relative to this view.
4855 section_size_type offset =
4856 convert_to_section_size_type(branch_address - view_address);
4857 gold_assert((offset + 4) <= view_size);
4859 arm_target->apply_cortex_a8_workaround(stub, stub_address,
4860 view + offset, branch_address);
4864 // Arm_input_section methods.
4866 // Initialize an Arm_input_section.
4868 template<bool big_endian>
4869 void
4870 Arm_input_section<big_endian>::init()
4872 Relobj* relobj = this->relobj();
4873 unsigned int shndx = this->shndx();
4875 // Cache these to speed up size and alignment queries. It is too slow
4876 // to call section_addraglin and section_size every time.
4877 this->original_addralign_ = relobj->section_addralign(shndx);
4878 this->original_size_ = relobj->section_size(shndx);
4880 // We want to make this look like the original input section after
4881 // output sections are finalized.
4882 Output_section* os = relobj->output_section(shndx);
4883 off_t offset = relobj->output_section_offset(shndx);
4884 gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
4885 this->set_address(os->address() + offset);
4886 this->set_file_offset(os->offset() + offset);
4888 this->set_current_data_size(this->original_size_);
4889 this->finalize_data_size();
4892 template<bool big_endian>
4893 void
4894 Arm_input_section<big_endian>::do_write(Output_file* of)
4896 // We have to write out the original section content.
4897 section_size_type section_size;
4898 const unsigned char* section_contents =
4899 this->relobj()->section_contents(this->shndx(), &section_size, false);
4900 of->write(this->offset(), section_contents, section_size);
4902 // If this owns a stub table and it is not empty, write it.
4903 if (this->is_stub_table_owner() && !this->stub_table_->empty())
4904 this->stub_table_->write(of);
4907 // Finalize data size.
4909 template<bool big_endian>
4910 void
4911 Arm_input_section<big_endian>::set_final_data_size()
4913 // If this owns a stub table, finalize its data size as well.
4914 if (this->is_stub_table_owner())
4916 uint64_t address = this->address();
4918 // The stub table comes after the original section contents.
4919 address += this->original_size_;
4920 address = align_address(address, this->stub_table_->addralign());
4921 off_t offset = this->offset() + (address - this->address());
4922 this->stub_table_->set_address_and_file_offset(address, offset);
4923 address += this->stub_table_->data_size();
4924 gold_assert(address == this->address() + this->current_data_size());
4927 this->set_data_size(this->current_data_size());
4930 // Reset address and file offset.
4932 template<bool big_endian>
4933 void
4934 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
4936 // Size of the original input section contents.
4937 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
4939 // If this is a stub table owner, account for the stub table size.
4940 if (this->is_stub_table_owner())
4942 Stub_table<big_endian>* stub_table = this->stub_table_;
4944 // Reset the stub table's address and file offset. The
4945 // current data size for child will be updated after that.
4946 stub_table_->reset_address_and_file_offset();
4947 off = align_address(off, stub_table_->addralign());
4948 off += stub_table->current_data_size();
4951 this->set_current_data_size(off);
4954 // Arm_exidx_cantunwind methods.
4956 // Write this to Output file OF for a fixed endianity.
4958 template<bool big_endian>
4959 void
4960 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
4962 off_t offset = this->offset();
4963 const section_size_type oview_size = 8;
4964 unsigned char* const oview = of->get_output_view(offset, oview_size);
4966 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
4967 Valtype* wv = reinterpret_cast<Valtype*>(oview);
4969 Output_section* os = this->relobj_->output_section(this->shndx_);
4970 gold_assert(os != NULL);
4972 Arm_relobj<big_endian>* arm_relobj =
4973 Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
4974 Arm_address output_offset =
4975 arm_relobj->get_output_section_offset(this->shndx_);
4976 Arm_address section_start;
4977 if(output_offset != Arm_relobj<big_endian>::invalid_address)
4978 section_start = os->address() + output_offset;
4979 else
4981 // Currently this only happens for a relaxed section.
4982 const Output_relaxed_input_section* poris =
4983 os->find_relaxed_input_section(this->relobj_, this->shndx_);
4984 gold_assert(poris != NULL);
4985 section_start = poris->address();
4988 // We always append this to the end of an EXIDX section.
4989 Arm_address output_address =
4990 section_start + this->relobj_->section_size(this->shndx_);
4992 // Write out the entry. The first word either points to the beginning
4993 // or after the end of a text section. The second word is the special
4994 // EXIDX_CANTUNWIND value.
4995 uint32_t prel31_offset = output_address - this->address();
4996 if (utils::has_overflow<31>(offset))
4997 gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
4998 elfcpp::Swap<32, big_endian>::writeval(wv, prel31_offset & 0x7fffffffU);
4999 elfcpp::Swap<32, big_endian>::writeval(wv + 1, elfcpp::EXIDX_CANTUNWIND);
5001 of->write_output_view(this->offset(), oview_size, oview);
5004 // Arm_exidx_merged_section methods.
5006 // Constructor for Arm_exidx_merged_section.
5007 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5008 // SECTION_OFFSET_MAP points to a section offset map describing how
5009 // parts of the input section are mapped to output. DELETED_BYTES is
5010 // the number of bytes deleted from the EXIDX input section.
5012 Arm_exidx_merged_section::Arm_exidx_merged_section(
5013 const Arm_exidx_input_section& exidx_input_section,
5014 const Arm_exidx_section_offset_map& section_offset_map,
5015 uint32_t deleted_bytes)
5016 : Output_relaxed_input_section(exidx_input_section.relobj(),
5017 exidx_input_section.shndx(),
5018 exidx_input_section.addralign()),
5019 exidx_input_section_(exidx_input_section),
5020 section_offset_map_(section_offset_map)
5022 // Fix size here so that we do not need to implement set_final_data_size.
5023 this->set_data_size(exidx_input_section.size() - deleted_bytes);
5024 this->fix_data_size();
5027 // Given an input OBJECT, an input section index SHNDX within that
5028 // object, and an OFFSET relative to the start of that input
5029 // section, return whether or not the corresponding offset within
5030 // the output section is known. If this function returns true, it
5031 // sets *POUTPUT to the output offset. The value -1 indicates that
5032 // this input offset is being discarded.
5034 bool
5035 Arm_exidx_merged_section::do_output_offset(
5036 const Relobj* relobj,
5037 unsigned int shndx,
5038 section_offset_type offset,
5039 section_offset_type* poutput) const
5041 // We only handle offsets for the original EXIDX input section.
5042 if (relobj != this->exidx_input_section_.relobj()
5043 || shndx != this->exidx_input_section_.shndx())
5044 return false;
5046 section_offset_type section_size =
5047 convert_types<section_offset_type>(this->exidx_input_section_.size());
5048 if (offset < 0 || offset >= section_size)
5049 // Input offset is out of valid range.
5050 *poutput = -1;
5051 else
5053 // We need to look up the section offset map to determine the output
5054 // offset. Find the reference point in map that is first offset
5055 // bigger than or equal to this offset.
5056 Arm_exidx_section_offset_map::const_iterator p =
5057 this->section_offset_map_.lower_bound(offset);
5059 // The section offset maps are build such that this should not happen if
5060 // input offset is in the valid range.
5061 gold_assert(p != this->section_offset_map_.end());
5063 // We need to check if this is dropped.
5064 section_offset_type ref = p->first;
5065 section_offset_type mapped_ref = p->second;
5067 if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5068 // Offset is present in output.
5069 *poutput = mapped_ref + (offset - ref);
5070 else
5071 // Offset is discarded owing to EXIDX entry merging.
5072 *poutput = -1;
5075 return true;
5078 // Write this to output file OF.
5080 void
5081 Arm_exidx_merged_section::do_write(Output_file* of)
5083 // If we retain or discard the whole EXIDX input section, we would
5084 // not be here.
5085 gold_assert(this->data_size() != this->exidx_input_section_.size()
5086 && this->data_size() != 0);
5088 off_t offset = this->offset();
5089 const section_size_type oview_size = this->data_size();
5090 unsigned char* const oview = of->get_output_view(offset, oview_size);
5092 Output_section* os = this->relobj()->output_section(this->shndx());
5093 gold_assert(os != NULL);
5095 // Get contents of EXIDX input section.
5096 section_size_type section_size;
5097 const unsigned char* section_contents =
5098 this->relobj()->section_contents(this->shndx(), &section_size, false);
5099 gold_assert(section_size == this->exidx_input_section_.size());
5101 // Go over spans of input offsets and write only those that are not
5102 // discarded.
5103 section_offset_type in_start = 0;
5104 section_offset_type out_start = 0;
5105 for(Arm_exidx_section_offset_map::const_iterator p =
5106 this->section_offset_map_.begin();
5107 p != this->section_offset_map_.end();
5108 ++p)
5110 section_offset_type in_end = p->first;
5111 gold_assert(in_end >= in_start);
5112 section_offset_type out_end = p->second;
5113 size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5114 if (out_end != -1)
5116 size_t out_chunk_size =
5117 convert_types<size_t>(out_end - out_start + 1);
5118 gold_assert(out_chunk_size == in_chunk_size);
5119 memcpy(oview + out_start, section_contents + in_start,
5120 out_chunk_size);
5121 out_start += out_chunk_size;
5123 in_start += in_chunk_size;
5126 gold_assert(convert_to_section_size_type(out_start) == oview_size);
5127 of->write_output_view(this->offset(), oview_size, oview);
5130 // Arm_exidx_fixup methods.
5132 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5133 // is not an EXIDX_CANTUNWIND entry already. The new EXIDX_CANTUNWIND entry
5134 // points to the end of the last seen EXIDX section.
5136 void
5137 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5139 if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5140 && this->last_input_section_ != NULL)
5142 Relobj* relobj = this->last_input_section_->relobj();
5143 unsigned int text_shndx = this->last_input_section_->link();
5144 Arm_exidx_cantunwind* cantunwind =
5145 new Arm_exidx_cantunwind(relobj, text_shndx);
5146 this->exidx_output_section_->add_output_section_data(cantunwind);
5147 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5151 // Process an EXIDX section entry in input. Return whether this entry
5152 // can be deleted in the output. SECOND_WORD in the second word of the
5153 // EXIDX entry.
5155 bool
5156 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5158 bool delete_entry;
5159 if (second_word == elfcpp::EXIDX_CANTUNWIND)
5161 // Merge if previous entry is also an EXIDX_CANTUNWIND.
5162 delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5163 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5165 else if ((second_word & 0x80000000) != 0)
5167 // Inlined unwinding data. Merge if equal to previous.
5168 delete_entry = (this->last_unwind_type_ == UT_INLINED_ENTRY
5169 && this->last_inlined_entry_ == second_word);
5170 this->last_unwind_type_ = UT_INLINED_ENTRY;
5171 this->last_inlined_entry_ = second_word;
5173 else
5175 // Normal table entry. In theory we could merge these too,
5176 // but duplicate entries are likely to be much less common.
5177 delete_entry = false;
5178 this->last_unwind_type_ = UT_NORMAL_ENTRY;
5180 return delete_entry;
5183 // Update the current section offset map during EXIDX section fix-up.
5184 // If there is no map, create one. INPUT_OFFSET is the offset of a
5185 // reference point, DELETED_BYTES is the number of deleted by in the
5186 // section so far. If DELETE_ENTRY is true, the reference point and
5187 // all offsets after the previous reference point are discarded.
5189 void
5190 Arm_exidx_fixup::update_offset_map(
5191 section_offset_type input_offset,
5192 section_size_type deleted_bytes,
5193 bool delete_entry)
5195 if (this->section_offset_map_ == NULL)
5196 this->section_offset_map_ = new Arm_exidx_section_offset_map();
5197 section_offset_type output_offset = (delete_entry
5198 ? -1
5199 : input_offset - deleted_bytes);
5200 (*this->section_offset_map_)[input_offset] = output_offset;
5203 // Process EXIDX_INPUT_SECTION for EXIDX entry merging. Return the number of
5204 // bytes deleted. If some entries are merged, also store a pointer to a newly
5205 // created Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP. The
5206 // caller owns the map and is responsible for releasing it after use.
5208 template<bool big_endian>
5209 uint32_t
5210 Arm_exidx_fixup::process_exidx_section(
5211 const Arm_exidx_input_section* exidx_input_section,
5212 Arm_exidx_section_offset_map** psection_offset_map)
5214 Relobj* relobj = exidx_input_section->relobj();
5215 unsigned shndx = exidx_input_section->shndx();
5216 section_size_type section_size;
5217 const unsigned char* section_contents =
5218 relobj->section_contents(shndx, &section_size, false);
5220 if ((section_size % 8) != 0)
5222 // Something is wrong with this section. Better not touch it.
5223 gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5224 relobj->name().c_str(), shndx);
5225 this->last_input_section_ = exidx_input_section;
5226 this->last_unwind_type_ = UT_NONE;
5227 return 0;
5230 uint32_t deleted_bytes = 0;
5231 bool prev_delete_entry = false;
5232 gold_assert(this->section_offset_map_ == NULL);
5234 for (section_size_type i = 0; i < section_size; i += 8)
5236 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5237 const Valtype* wv =
5238 reinterpret_cast<const Valtype*>(section_contents + i + 4);
5239 uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5241 bool delete_entry = this->process_exidx_entry(second_word);
5243 // Entry deletion causes changes in output offsets. We use a std::map
5244 // to record these. And entry (x, y) means input offset x
5245 // is mapped to output offset y. If y is invalid_offset, then x is
5246 // dropped in the output. Because of the way std::map::lower_bound
5247 // works, we record the last offset in a region w.r.t to keeping or
5248 // dropping. If there is no entry (x0, y0) for an input offset x0,
5249 // the output offset y0 of it is determined by the output offset y1 of
5250 // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5251 // in the map. If y1 is not -1, then y0 = y1 + x0 - x1. Othewise, y1
5252 // y0 is also -1.
5253 if (delete_entry != prev_delete_entry && i != 0)
5254 this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5256 // Update total deleted bytes for this entry.
5257 if (delete_entry)
5258 deleted_bytes += 8;
5260 prev_delete_entry = delete_entry;
5263 // If section offset map is not NULL, make an entry for the end of
5264 // section.
5265 if (this->section_offset_map_ != NULL)
5266 update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5268 *psection_offset_map = this->section_offset_map_;
5269 this->section_offset_map_ = NULL;
5270 this->last_input_section_ = exidx_input_section;
5272 // Set the first output text section so that we can link the EXIDX output
5273 // section to it. Ignore any EXIDX input section that is completely merged.
5274 if (this->first_output_text_section_ == NULL
5275 && deleted_bytes != section_size)
5277 unsigned int link = exidx_input_section->link();
5278 Output_section* os = relobj->output_section(link);
5279 gold_assert(os != NULL);
5280 this->first_output_text_section_ = os;
5283 return deleted_bytes;
5286 // Arm_output_section methods.
5288 // Create a stub group for input sections from BEGIN to END. OWNER
5289 // points to the input section to be the owner a new stub table.
5291 template<bool big_endian>
5292 void
5293 Arm_output_section<big_endian>::create_stub_group(
5294 Input_section_list::const_iterator begin,
5295 Input_section_list::const_iterator end,
5296 Input_section_list::const_iterator owner,
5297 Target_arm<big_endian>* target,
5298 std::vector<Output_relaxed_input_section*>* new_relaxed_sections)
5300 // We use a different kind of relaxed section in an EXIDX section.
5301 // The static casting from Output_relaxed_input_section to
5302 // Arm_input_section is invalid in an EXIDX section. We are okay
5303 // because we should not be calling this for an EXIDX section.
5304 gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5306 // Currently we convert ordinary input sections into relaxed sections only
5307 // at this point but we may want to support creating relaxed input section
5308 // very early. So we check here to see if owner is already a relaxed
5309 // section.
5311 Arm_input_section<big_endian>* arm_input_section;
5312 if (owner->is_relaxed_input_section())
5314 arm_input_section =
5315 Arm_input_section<big_endian>::as_arm_input_section(
5316 owner->relaxed_input_section());
5318 else
5320 gold_assert(owner->is_input_section());
5321 // Create a new relaxed input section.
5322 arm_input_section =
5323 target->new_arm_input_section(owner->relobj(), owner->shndx());
5324 new_relaxed_sections->push_back(arm_input_section);
5327 // Create a stub table.
5328 Stub_table<big_endian>* stub_table =
5329 target->new_stub_table(arm_input_section);
5331 arm_input_section->set_stub_table(stub_table);
5333 Input_section_list::const_iterator p = begin;
5334 Input_section_list::const_iterator prev_p;
5336 // Look for input sections or relaxed input sections in [begin ... end].
5339 if (p->is_input_section() || p->is_relaxed_input_section())
5341 // The stub table information for input sections live
5342 // in their objects.
5343 Arm_relobj<big_endian>* arm_relobj =
5344 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5345 arm_relobj->set_stub_table(p->shndx(), stub_table);
5347 prev_p = p++;
5349 while (prev_p != end);
5352 // Group input sections for stub generation. GROUP_SIZE is roughly the limit
5353 // of stub groups. We grow a stub group by adding input section until the
5354 // size is just below GROUP_SIZE. The last input section will be converted
5355 // into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5356 // input section after the stub table, effectively double the group size.
5358 // This is similar to the group_sections() function in elf32-arm.c but is
5359 // implemented differently.
5361 template<bool big_endian>
5362 void
5363 Arm_output_section<big_endian>::group_sections(
5364 section_size_type group_size,
5365 bool stubs_always_after_branch,
5366 Target_arm<big_endian>* target)
5368 // We only care about sections containing code.
5369 if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
5370 return;
5372 // States for grouping.
5373 typedef enum
5375 // No group is being built.
5376 NO_GROUP,
5377 // A group is being built but the stub table is not found yet.
5378 // We keep group a stub group until the size is just under GROUP_SIZE.
5379 // The last input section in the group will be used as the stub table.
5380 FINDING_STUB_SECTION,
5381 // A group is being built and we have already found a stub table.
5382 // We enter this state to grow a stub group by adding input section
5383 // after the stub table. This effectively doubles the group size.
5384 HAS_STUB_SECTION
5385 } State;
5387 // Any newly created relaxed sections are stored here.
5388 std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5390 State state = NO_GROUP;
5391 section_size_type off = 0;
5392 section_size_type group_begin_offset = 0;
5393 section_size_type group_end_offset = 0;
5394 section_size_type stub_table_end_offset = 0;
5395 Input_section_list::const_iterator group_begin =
5396 this->input_sections().end();
5397 Input_section_list::const_iterator stub_table =
5398 this->input_sections().end();
5399 Input_section_list::const_iterator group_end = this->input_sections().end();
5400 for (Input_section_list::const_iterator p = this->input_sections().begin();
5401 p != this->input_sections().end();
5402 ++p)
5404 section_size_type section_begin_offset =
5405 align_address(off, p->addralign());
5406 section_size_type section_end_offset =
5407 section_begin_offset + p->data_size();
5409 // Check to see if we should group the previously seens sections.
5410 switch (state)
5412 case NO_GROUP:
5413 break;
5415 case FINDING_STUB_SECTION:
5416 // Adding this section makes the group larger than GROUP_SIZE.
5417 if (section_end_offset - group_begin_offset >= group_size)
5419 if (stubs_always_after_branch)
5421 gold_assert(group_end != this->input_sections().end());
5422 this->create_stub_group(group_begin, group_end, group_end,
5423 target, &new_relaxed_sections);
5424 state = NO_GROUP;
5426 else
5428 // But wait, there's more! Input sections up to
5429 // stub_group_size bytes after the stub table can be
5430 // handled by it too.
5431 state = HAS_STUB_SECTION;
5432 stub_table = group_end;
5433 stub_table_end_offset = group_end_offset;
5436 break;
5438 case HAS_STUB_SECTION:
5439 // Adding this section makes the post stub-section group larger
5440 // than GROUP_SIZE.
5441 if (section_end_offset - stub_table_end_offset >= group_size)
5443 gold_assert(group_end != this->input_sections().end());
5444 this->create_stub_group(group_begin, group_end, stub_table,
5445 target, &new_relaxed_sections);
5446 state = NO_GROUP;
5448 break;
5450 default:
5451 gold_unreachable();
5454 // If we see an input section and currently there is no group, start
5455 // a new one. Skip any empty sections.
5456 if ((p->is_input_section() || p->is_relaxed_input_section())
5457 && (p->relobj()->section_size(p->shndx()) != 0))
5459 if (state == NO_GROUP)
5461 state = FINDING_STUB_SECTION;
5462 group_begin = p;
5463 group_begin_offset = section_begin_offset;
5466 // Keep track of the last input section seen.
5467 group_end = p;
5468 group_end_offset = section_end_offset;
5471 off = section_end_offset;
5474 // Create a stub group for any ungrouped sections.
5475 if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5477 gold_assert(group_end != this->input_sections().end());
5478 this->create_stub_group(group_begin, group_end,
5479 (state == FINDING_STUB_SECTION
5480 ? group_end
5481 : stub_table),
5482 target, &new_relaxed_sections);
5485 // Convert input section into relaxed input section in a batch.
5486 if (!new_relaxed_sections.empty())
5487 this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5489 // Update the section offsets
5490 for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5492 Arm_relobj<big_endian>* arm_relobj =
5493 Arm_relobj<big_endian>::as_arm_relobj(
5494 new_relaxed_sections[i]->relobj());
5495 unsigned int shndx = new_relaxed_sections[i]->shndx();
5496 // Tell Arm_relobj that this input section is converted.
5497 arm_relobj->convert_input_section_to_relaxed_section(shndx);
5501 // Append non empty text sections in this to LIST in ascending
5502 // order of their position in this.
5504 template<bool big_endian>
5505 void
5506 Arm_output_section<big_endian>::append_text_sections_to_list(
5507 Text_section_list* list)
5509 // We only care about text sections.
5510 if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
5511 return;
5513 gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5515 for (Input_section_list::const_iterator p = this->input_sections().begin();
5516 p != this->input_sections().end();
5517 ++p)
5519 // We only care about plain or relaxed input sections. We also
5520 // ignore any merged sections.
5521 if ((p->is_input_section() || p->is_relaxed_input_section())
5522 && p->data_size() != 0)
5523 list->push_back(Text_section_list::value_type(p->relobj(),
5524 p->shndx()));
5528 template<bool big_endian>
5529 void
5530 Arm_output_section<big_endian>::fix_exidx_coverage(
5531 Layout* layout,
5532 const Text_section_list& sorted_text_sections,
5533 Symbol_table* symtab)
5535 // We should only do this for the EXIDX output section.
5536 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5538 // We don't want the relaxation loop to undo these changes, so we discard
5539 // the current saved states and take another one after the fix-up.
5540 this->discard_states();
5542 // Remove all input sections.
5543 uint64_t address = this->address();
5544 typedef std::list<Simple_input_section> Simple_input_section_list;
5545 Simple_input_section_list input_sections;
5546 this->reset_address_and_file_offset();
5547 this->get_input_sections(address, std::string(""), &input_sections);
5549 if (!this->input_sections().empty())
5550 gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5552 // Go through all the known input sections and record them.
5553 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5554 Section_id_set known_input_sections;
5555 for (Simple_input_section_list::const_iterator p = input_sections.begin();
5556 p != input_sections.end();
5557 ++p)
5559 // This should never happen. At this point, we should only see
5560 // plain EXIDX input sections.
5561 gold_assert(!p->is_relaxed_input_section());
5562 known_input_sections.insert(Section_id(p->relobj(), p->shndx()));
5565 Arm_exidx_fixup exidx_fixup(this);
5567 // Go over the sorted text sections.
5568 Section_id_set processed_input_sections;
5569 for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5570 p != sorted_text_sections.end();
5571 ++p)
5573 Relobj* relobj = p->first;
5574 unsigned int shndx = p->second;
5576 Arm_relobj<big_endian>* arm_relobj =
5577 Arm_relobj<big_endian>::as_arm_relobj(relobj);
5578 const Arm_exidx_input_section* exidx_input_section =
5579 arm_relobj->exidx_input_section_by_link(shndx);
5581 // If this text section has no EXIDX section, force an EXIDX_CANTUNWIND
5582 // entry pointing to the end of the last seen EXIDX section.
5583 if (exidx_input_section == NULL)
5585 exidx_fixup.add_exidx_cantunwind_as_needed();
5586 continue;
5589 Relobj* exidx_relobj = exidx_input_section->relobj();
5590 unsigned int exidx_shndx = exidx_input_section->shndx();
5591 Section_id sid(exidx_relobj, exidx_shndx);
5592 if (known_input_sections.find(sid) == known_input_sections.end())
5594 // This is odd. We have not seen this EXIDX input section before.
5595 // We cannot do fix-up. If we saw a SECTIONS clause in a script,
5596 // issue a warning instead. We assume the user knows what he
5597 // or she is doing. Otherwise, this is an error.
5598 if (layout->script_options()->saw_sections_clause())
5599 gold_warning(_("unwinding may not work because EXIDX input section"
5600 " %u of %s is not in EXIDX output section"),
5601 exidx_shndx, exidx_relobj->name().c_str());
5602 else
5603 gold_error(_("unwinding may not work because EXIDX input section"
5604 " %u of %s is not in EXIDX output section"),
5605 exidx_shndx, exidx_relobj->name().c_str());
5607 exidx_fixup.add_exidx_cantunwind_as_needed();
5608 continue;
5611 // Fix up coverage and append input section to output data list.
5612 Arm_exidx_section_offset_map* section_offset_map = NULL;
5613 uint32_t deleted_bytes =
5614 exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5615 &section_offset_map);
5617 if (deleted_bytes == exidx_input_section->size())
5619 // The whole EXIDX section got merged. Remove it from output.
5620 gold_assert(section_offset_map == NULL);
5621 exidx_relobj->set_output_section(exidx_shndx, NULL);
5623 // All local symbols defined in this input section will be dropped.
5624 // We need to adjust output local symbol count.
5625 arm_relobj->set_output_local_symbol_count_needs_update();
5627 else if (deleted_bytes > 0)
5629 // Some entries are merged. We need to convert this EXIDX input
5630 // section into a relaxed section.
5631 gold_assert(section_offset_map != NULL);
5632 Arm_exidx_merged_section* merged_section =
5633 new Arm_exidx_merged_section(*exidx_input_section,
5634 *section_offset_map, deleted_bytes);
5635 this->add_relaxed_input_section(merged_section);
5636 arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5638 // All local symbols defined in discarded portions of this input
5639 // section will be dropped. We need to adjust output local symbol
5640 // count.
5641 arm_relobj->set_output_local_symbol_count_needs_update();
5643 else
5645 // Just add back the EXIDX input section.
5646 gold_assert(section_offset_map == NULL);
5647 Output_section::Simple_input_section sis(exidx_relobj, exidx_shndx);
5648 this->add_simple_input_section(sis, exidx_input_section->size(),
5649 exidx_input_section->addralign());
5652 processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5655 // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5656 exidx_fixup.add_exidx_cantunwind_as_needed();
5658 // Remove any known EXIDX input sections that are not processed.
5659 for (Simple_input_section_list::const_iterator p = input_sections.begin();
5660 p != input_sections.end();
5661 ++p)
5663 if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5664 == processed_input_sections.end())
5666 // We only discard a known EXIDX section because its linked
5667 // text section has been folded by ICF.
5668 Arm_relobj<big_endian>* arm_relobj =
5669 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5670 const Arm_exidx_input_section* exidx_input_section =
5671 arm_relobj->exidx_input_section_by_shndx(p->shndx());
5672 gold_assert(exidx_input_section != NULL);
5673 unsigned int text_shndx = exidx_input_section->link();
5674 gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5676 // Remove this from link.
5677 p->relobj()->set_output_section(p->shndx(), NULL);
5681 // Link exidx output section to the first seen output section and
5682 // set correct entry size.
5683 this->set_link_section(exidx_fixup.first_output_text_section());
5684 this->set_entsize(8);
5686 // Make changes permanent.
5687 this->save_states();
5688 this->set_section_offsets_need_adjustment();
5691 // Arm_relobj methods.
5693 // Determine if an input section is scannable for stub processing. SHDR is
5694 // the header of the section and SHNDX is the section index. OS is the output
5695 // section for the input section and SYMTAB is the global symbol table used to
5696 // look up ICF information.
5698 template<bool big_endian>
5699 bool
5700 Arm_relobj<big_endian>::section_is_scannable(
5701 const elfcpp::Shdr<32, big_endian>& shdr,
5702 unsigned int shndx,
5703 const Output_section* os,
5704 const Symbol_table *symtab)
5706 // Skip any empty sections, unallocated sections or sections whose
5707 // type are not SHT_PROGBITS.
5708 if (shdr.get_sh_size() == 0
5709 || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
5710 || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
5711 return false;
5713 // Skip any discarded or ICF'ed sections.
5714 if (os == NULL || symtab->is_section_folded(this, shndx))
5715 return false;
5717 // If this requires special offset handling, check to see if it is
5718 // a relaxed section. If this is not, then it is a merged section that
5719 // we cannot handle.
5720 if (this->is_output_section_offset_invalid(shndx))
5722 const Output_relaxed_input_section* poris =
5723 os->find_relaxed_input_section(this, shndx);
5724 if (poris == NULL)
5725 return false;
5728 return true;
5731 // Determine if we want to scan the SHNDX-th section for relocation stubs.
5732 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
5734 template<bool big_endian>
5735 bool
5736 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
5737 const elfcpp::Shdr<32, big_endian>& shdr,
5738 const Relobj::Output_sections& out_sections,
5739 const Symbol_table *symtab,
5740 const unsigned char* pshdrs)
5742 unsigned int sh_type = shdr.get_sh_type();
5743 if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
5744 return false;
5746 // Ignore empty section.
5747 off_t sh_size = shdr.get_sh_size();
5748 if (sh_size == 0)
5749 return false;
5751 // Ignore reloc section with unexpected symbol table. The
5752 // error will be reported in the final link.
5753 if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
5754 return false;
5756 unsigned int reloc_size;
5757 if (sh_type == elfcpp::SHT_REL)
5758 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
5759 else
5760 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
5762 // Ignore reloc section with unexpected entsize or uneven size.
5763 // The error will be reported in the final link.
5764 if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
5765 return false;
5767 // Ignore reloc section with bad info. This error will be
5768 // reported in the final link.
5769 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
5770 if (index >= this->shnum())
5771 return false;
5773 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
5774 const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
5775 return this->section_is_scannable(text_shdr, index,
5776 out_sections[index], symtab);
5779 // Return the output address of either a plain input section or a relaxed
5780 // input section. SHNDX is the section index. We define and use this
5781 // instead of calling Output_section::output_address because that is slow
5782 // for large output.
5784 template<bool big_endian>
5785 Arm_address
5786 Arm_relobj<big_endian>::simple_input_section_output_address(
5787 unsigned int shndx,
5788 Output_section* os)
5790 if (this->is_output_section_offset_invalid(shndx))
5792 const Output_relaxed_input_section* poris =
5793 os->find_relaxed_input_section(this, shndx);
5794 // We do not handle merged sections here.
5795 gold_assert(poris != NULL);
5796 return poris->address();
5798 else
5799 return os->address() + this->get_output_section_offset(shndx);
5802 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
5803 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
5805 template<bool big_endian>
5806 bool
5807 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
5808 const elfcpp::Shdr<32, big_endian>& shdr,
5809 unsigned int shndx,
5810 Output_section* os,
5811 const Symbol_table* symtab)
5813 if (!this->section_is_scannable(shdr, shndx, os, symtab))
5814 return false;
5816 // If the section does not cross any 4K-boundaries, it does not need to
5817 // be scanned.
5818 Arm_address address = this->simple_input_section_output_address(shndx, os);
5819 if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
5820 return false;
5822 return true;
5825 // Scan a section for Cortex-A8 workaround.
5827 template<bool big_endian>
5828 void
5829 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
5830 const elfcpp::Shdr<32, big_endian>& shdr,
5831 unsigned int shndx,
5832 Output_section* os,
5833 Target_arm<big_endian>* arm_target)
5835 // Look for the first mapping symbol in this section. It should be
5836 // at (shndx, 0).
5837 Mapping_symbol_position section_start(shndx, 0);
5838 typename Mapping_symbols_info::const_iterator p =
5839 this->mapping_symbols_info_.lower_bound(section_start);
5841 // There are no mapping symbols for this section. Treat it as a data-only
5842 // section.
5843 if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
5844 return;
5846 Arm_address output_address =
5847 this->simple_input_section_output_address(shndx, os);
5849 // Get the section contents.
5850 section_size_type input_view_size = 0;
5851 const unsigned char* input_view =
5852 this->section_contents(shndx, &input_view_size, false);
5854 // We need to go through the mapping symbols to determine what to
5855 // scan. There are two reasons. First, we should look at THUMB code and
5856 // THUMB code only. Second, we only want to look at the 4K-page boundary
5857 // to speed up the scanning.
5859 while (p != this->mapping_symbols_info_.end()
5860 && p->first.first == shndx)
5862 typename Mapping_symbols_info::const_iterator next =
5863 this->mapping_symbols_info_.upper_bound(p->first);
5865 // Only scan part of a section with THUMB code.
5866 if (p->second == 't')
5868 // Determine the end of this range.
5869 section_size_type span_start =
5870 convert_to_section_size_type(p->first.second);
5871 section_size_type span_end;
5872 if (next != this->mapping_symbols_info_.end()
5873 && next->first.first == shndx)
5874 span_end = convert_to_section_size_type(next->first.second);
5875 else
5876 span_end = convert_to_section_size_type(shdr.get_sh_size());
5878 if (((span_start + output_address) & ~0xfffUL)
5879 != ((span_end + output_address - 1) & ~0xfffUL))
5881 arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
5882 span_start, span_end,
5883 input_view,
5884 output_address);
5888 p = next;
5892 // Scan relocations for stub generation.
5894 template<bool big_endian>
5895 void
5896 Arm_relobj<big_endian>::scan_sections_for_stubs(
5897 Target_arm<big_endian>* arm_target,
5898 const Symbol_table* symtab,
5899 const Layout* layout)
5901 unsigned int shnum = this->shnum();
5902 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
5904 // Read the section headers.
5905 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
5906 shnum * shdr_size,
5907 true, true);
5909 // To speed up processing, we set up hash tables for fast lookup of
5910 // input offsets to output addresses.
5911 this->initialize_input_to_output_maps();
5913 const Relobj::Output_sections& out_sections(this->output_sections());
5915 Relocate_info<32, big_endian> relinfo;
5916 relinfo.symtab = symtab;
5917 relinfo.layout = layout;
5918 relinfo.object = this;
5920 // Do relocation stubs scanning.
5921 const unsigned char* p = pshdrs + shdr_size;
5922 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
5924 const elfcpp::Shdr<32, big_endian> shdr(p);
5925 if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
5926 pshdrs))
5928 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
5929 Arm_address output_offset = this->get_output_section_offset(index);
5930 Arm_address output_address;
5931 if(output_offset != invalid_address)
5932 output_address = out_sections[index]->address() + output_offset;
5933 else
5935 // Currently this only happens for a relaxed section.
5936 const Output_relaxed_input_section* poris =
5937 out_sections[index]->find_relaxed_input_section(this, index);
5938 gold_assert(poris != NULL);
5939 output_address = poris->address();
5942 // Get the relocations.
5943 const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
5944 shdr.get_sh_size(),
5945 true, false);
5947 // Get the section contents. This does work for the case in which
5948 // we modify the contents of an input section. We need to pass the
5949 // output view under such circumstances.
5950 section_size_type input_view_size = 0;
5951 const unsigned char* input_view =
5952 this->section_contents(index, &input_view_size, false);
5954 relinfo.reloc_shndx = i;
5955 relinfo.data_shndx = index;
5956 unsigned int sh_type = shdr.get_sh_type();
5957 unsigned int reloc_size;
5958 if (sh_type == elfcpp::SHT_REL)
5959 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
5960 else
5961 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
5963 Output_section* os = out_sections[index];
5964 arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
5965 shdr.get_sh_size() / reloc_size,
5967 output_offset == invalid_address,
5968 input_view, output_address,
5969 input_view_size);
5973 // Do Cortex-A8 erratum stubs scanning. This has to be done for a section
5974 // after its relocation section, if there is one, is processed for
5975 // relocation stubs. Merging this loop with the one above would have been
5976 // complicated since we would have had to make sure that relocation stub
5977 // scanning is done first.
5978 if (arm_target->fix_cortex_a8())
5980 const unsigned char* p = pshdrs + shdr_size;
5981 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
5983 const elfcpp::Shdr<32, big_endian> shdr(p);
5984 if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
5985 out_sections[i],
5986 symtab))
5987 this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
5988 arm_target);
5992 // After we've done the relocations, we release the hash tables,
5993 // since we no longer need them.
5994 this->free_input_to_output_maps();
5997 // Count the local symbols. The ARM backend needs to know if a symbol
5998 // is a THUMB function or not. For global symbols, it is easy because
5999 // the Symbol object keeps the ELF symbol type. For local symbol it is
6000 // harder because we cannot access this information. So we override the
6001 // do_count_local_symbol in parent and scan local symbols to mark
6002 // THUMB functions. This is not the most efficient way but I do not want to
6003 // slow down other ports by calling a per symbol targer hook inside
6004 // Sized_relobj<size, big_endian>::do_count_local_symbols.
6006 template<bool big_endian>
6007 void
6008 Arm_relobj<big_endian>::do_count_local_symbols(
6009 Stringpool_template<char>* pool,
6010 Stringpool_template<char>* dynpool)
6012 // We need to fix-up the values of any local symbols whose type are
6013 // STT_ARM_TFUNC.
6015 // Ask parent to count the local symbols.
6016 Sized_relobj<32, big_endian>::do_count_local_symbols(pool, dynpool);
6017 const unsigned int loccount = this->local_symbol_count();
6018 if (loccount == 0)
6019 return;
6021 // Intialize the thumb function bit-vector.
6022 std::vector<bool> empty_vector(loccount, false);
6023 this->local_symbol_is_thumb_function_.swap(empty_vector);
6025 // Read the symbol table section header.
6026 const unsigned int symtab_shndx = this->symtab_shndx();
6027 elfcpp::Shdr<32, big_endian>
6028 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6029 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6031 // Read the local symbols.
6032 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6033 gold_assert(loccount == symtabshdr.get_sh_info());
6034 off_t locsize = loccount * sym_size;
6035 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6036 locsize, true, true);
6038 // For mapping symbol processing, we need to read the symbol names.
6039 unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6040 if (strtab_shndx >= this->shnum())
6042 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6043 return;
6046 elfcpp::Shdr<32, big_endian>
6047 strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6048 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6050 this->error(_("symbol table name section has wrong type: %u"),
6051 static_cast<unsigned int>(strtabshdr.get_sh_type()));
6052 return;
6054 const char* pnames =
6055 reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6056 strtabshdr.get_sh_size(),
6057 false, false));
6059 // Loop over the local symbols and mark any local symbols pointing
6060 // to THUMB functions.
6062 // Skip the first dummy symbol.
6063 psyms += sym_size;
6064 typename Sized_relobj<32, big_endian>::Local_values* plocal_values =
6065 this->local_values();
6066 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6068 elfcpp::Sym<32, big_endian> sym(psyms);
6069 elfcpp::STT st_type = sym.get_st_type();
6070 Symbol_value<32>& lv((*plocal_values)[i]);
6071 Arm_address input_value = lv.input_value();
6073 // Check to see if this is a mapping symbol.
6074 const char* sym_name = pnames + sym.get_st_name();
6075 if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6077 unsigned int input_shndx = sym.get_st_shndx();
6079 // Strip of LSB in case this is a THUMB symbol.
6080 Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6081 this->mapping_symbols_info_[msp] = sym_name[1];
6084 if (st_type == elfcpp::STT_ARM_TFUNC
6085 || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6087 // This is a THUMB function. Mark this and canonicalize the
6088 // symbol value by setting LSB.
6089 this->local_symbol_is_thumb_function_[i] = true;
6090 if ((input_value & 1) == 0)
6091 lv.set_input_value(input_value | 1);
6096 // Relocate sections.
6097 template<bool big_endian>
6098 void
6099 Arm_relobj<big_endian>::do_relocate_sections(
6100 const Symbol_table* symtab,
6101 const Layout* layout,
6102 const unsigned char* pshdrs,
6103 typename Sized_relobj<32, big_endian>::Views* pviews)
6105 // Call parent to relocate sections.
6106 Sized_relobj<32, big_endian>::do_relocate_sections(symtab, layout, pshdrs,
6107 pviews);
6109 // We do not generate stubs if doing a relocatable link.
6110 if (parameters->options().relocatable())
6111 return;
6113 // Relocate stub tables.
6114 unsigned int shnum = this->shnum();
6116 Target_arm<big_endian>* arm_target =
6117 Target_arm<big_endian>::default_target();
6119 Relocate_info<32, big_endian> relinfo;
6120 relinfo.symtab = symtab;
6121 relinfo.layout = layout;
6122 relinfo.object = this;
6124 for (unsigned int i = 1; i < shnum; ++i)
6126 Arm_input_section<big_endian>* arm_input_section =
6127 arm_target->find_arm_input_section(this, i);
6129 if (arm_input_section != NULL
6130 && arm_input_section->is_stub_table_owner()
6131 && !arm_input_section->stub_table()->empty())
6133 // We cannot discard a section if it owns a stub table.
6134 Output_section* os = this->output_section(i);
6135 gold_assert(os != NULL);
6137 relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6138 relinfo.reloc_shdr = NULL;
6139 relinfo.data_shndx = i;
6140 relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6142 gold_assert((*pviews)[i].view != NULL);
6144 // We are passed the output section view. Adjust it to cover the
6145 // stub table only.
6146 Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6147 gold_assert((stub_table->address() >= (*pviews)[i].address)
6148 && ((stub_table->address() + stub_table->data_size())
6149 <= (*pviews)[i].address + (*pviews)[i].view_size));
6151 off_t offset = stub_table->address() - (*pviews)[i].address;
6152 unsigned char* view = (*pviews)[i].view + offset;
6153 Arm_address address = stub_table->address();
6154 section_size_type view_size = stub_table->data_size();
6156 stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6157 view_size);
6160 // Apply Cortex A8 workaround if applicable.
6161 if (this->section_has_cortex_a8_workaround(i))
6163 unsigned char* view = (*pviews)[i].view;
6164 Arm_address view_address = (*pviews)[i].address;
6165 section_size_type view_size = (*pviews)[i].view_size;
6166 Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6168 // Adjust view to cover section.
6169 Output_section* os = this->output_section(i);
6170 gold_assert(os != NULL);
6171 Arm_address section_address =
6172 this->simple_input_section_output_address(i, os);
6173 uint64_t section_size = this->section_size(i);
6175 gold_assert(section_address >= view_address
6176 && ((section_address + section_size)
6177 <= (view_address + view_size)));
6179 unsigned char* section_view = view + (section_address - view_address);
6181 // Apply the Cortex-A8 workaround to the output address range
6182 // corresponding to this input section.
6183 stub_table->apply_cortex_a8_workaround_to_address_range(
6184 arm_target,
6185 section_view,
6186 section_address,
6187 section_size);
6192 // Find the linked text section of an EXIDX section by looking the the first
6193 // relocation. 4.4.1 of the EHABI specifications says that an EXIDX section
6194 // must be linked to to its associated code section via the sh_link field of
6195 // its section header. However, some tools are broken and the link is not
6196 // always set. LD just drops such an EXIDX section silently, causing the
6197 // associated code not unwindabled. Here we try a little bit harder to
6198 // discover the linked code section.
6200 // PSHDR points to the section header of a relocation section of an EXIDX
6201 // section. If we can find a linked text section, return true and
6202 // store the text section index in the location PSHNDX. Otherwise
6203 // return false.
6205 template<bool big_endian>
6206 bool
6207 Arm_relobj<big_endian>::find_linked_text_section(
6208 const unsigned char* pshdr,
6209 const unsigned char* psyms,
6210 unsigned int* pshndx)
6212 elfcpp::Shdr<32, big_endian> shdr(pshdr);
6214 // If there is no relocation, we cannot find the linked text section.
6215 size_t reloc_size;
6216 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6217 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6218 else
6219 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6220 size_t reloc_count = shdr.get_sh_size() / reloc_size;
6222 // Get the relocations.
6223 const unsigned char* prelocs =
6224 this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6226 // Find the REL31 relocation for the first word of the first EXIDX entry.
6227 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6229 Arm_address r_offset;
6230 typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6231 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6233 typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6234 r_info = reloc.get_r_info();
6235 r_offset = reloc.get_r_offset();
6237 else
6239 typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6240 r_info = reloc.get_r_info();
6241 r_offset = reloc.get_r_offset();
6244 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6245 if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6246 continue;
6248 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6249 if (r_sym == 0
6250 || r_sym >= this->local_symbol_count()
6251 || r_offset != 0)
6252 continue;
6254 // This is the relocation for the first word of the first EXIDX entry.
6255 // We expect to see a local section symbol.
6256 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6257 elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6258 if (sym.get_st_type() == elfcpp::STT_SECTION)
6260 *pshndx = this->adjust_shndx(sym.get_st_shndx());
6261 return true;
6263 else
6264 return false;
6267 return false;
6270 // Make an EXIDX input section object for an EXIDX section whose index is
6271 // SHNDX. SHDR is the section header of the EXIDX section and TEXT_SHNDX
6272 // is the section index of the linked text section.
6274 template<bool big_endian>
6275 void
6276 Arm_relobj<big_endian>::make_exidx_input_section(
6277 unsigned int shndx,
6278 const elfcpp::Shdr<32, big_endian>& shdr,
6279 unsigned int text_shndx)
6281 // Issue an error and ignore this EXIDX section if it points to a text
6282 // section already has an EXIDX section.
6283 if (this->exidx_section_map_[text_shndx] != NULL)
6285 gold_error(_("EXIDX sections %u and %u both link to text section %u "
6286 "in %s"),
6287 shndx, this->exidx_section_map_[text_shndx]->shndx(),
6288 text_shndx, this->name().c_str());
6289 return;
6292 // Create an Arm_exidx_input_section object for this EXIDX section.
6293 Arm_exidx_input_section* exidx_input_section =
6294 new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6295 shdr.get_sh_addralign());
6296 this->exidx_section_map_[text_shndx] = exidx_input_section;
6298 // Also map the EXIDX section index to this.
6299 gold_assert(this->exidx_section_map_[shndx] == NULL);
6300 this->exidx_section_map_[shndx] = exidx_input_section;
6303 // Read the symbol information.
6305 template<bool big_endian>
6306 void
6307 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6309 // Call parent class to read symbol information.
6310 Sized_relobj<32, big_endian>::do_read_symbols(sd);
6312 // Read processor-specific flags in ELF file header.
6313 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6314 elfcpp::Elf_sizes<32>::ehdr_size,
6315 true, false);
6316 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6317 this->processor_specific_flags_ = ehdr.get_e_flags();
6319 // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6320 // sections.
6321 std::vector<unsigned int> deferred_exidx_sections;
6322 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6323 const unsigned char* pshdrs = sd->section_headers->data();
6324 const unsigned char *ps = pshdrs + shdr_size;
6325 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6327 elfcpp::Shdr<32, big_endian> shdr(ps);
6328 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6330 gold_assert(this->attributes_section_data_ == NULL);
6331 section_offset_type section_offset = shdr.get_sh_offset();
6332 section_size_type section_size =
6333 convert_to_section_size_type(shdr.get_sh_size());
6334 File_view* view = this->get_lasting_view(section_offset,
6335 section_size, true, false);
6336 this->attributes_section_data_ =
6337 new Attributes_section_data(view->data(), section_size);
6339 else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6341 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6342 if (text_shndx >= this->shnum())
6343 gold_error(_("EXIDX section %u linked to invalid section %u"),
6344 i, text_shndx);
6345 else if (text_shndx == elfcpp::SHN_UNDEF)
6346 deferred_exidx_sections.push_back(i);
6347 else
6348 this->make_exidx_input_section(i, shdr, text_shndx);
6352 // Some tools are broken and they do not set the link of EXIDX sections.
6353 // We look at the first relocation to figure out the linked sections.
6354 if (!deferred_exidx_sections.empty())
6356 // We need to go over the section headers again to find the mapping
6357 // from sections being relocated to their relocation sections. This is
6358 // a bit inefficient as we could do that in the loop above. However,
6359 // we do not expect any deferred EXIDX sections normally. So we do not
6360 // want to slow down the most common path.
6361 typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6362 Reloc_map reloc_map;
6363 ps = pshdrs + shdr_size;
6364 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6366 elfcpp::Shdr<32, big_endian> shdr(ps);
6367 elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6368 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6370 unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6371 if (info_shndx >= this->shnum())
6372 gold_error(_("relocation section %u has invalid info %u"),
6373 i, info_shndx);
6374 Reloc_map::value_type value(info_shndx, i);
6375 std::pair<Reloc_map::iterator, bool> result =
6376 reloc_map.insert(value);
6377 if (!result.second)
6378 gold_error(_("section %u has multiple relocation sections "
6379 "%u and %u"),
6380 info_shndx, i, reloc_map[info_shndx]);
6384 // Read the symbol table section header.
6385 const unsigned int symtab_shndx = this->symtab_shndx();
6386 elfcpp::Shdr<32, big_endian>
6387 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6388 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6390 // Read the local symbols.
6391 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6392 const unsigned int loccount = this->local_symbol_count();
6393 gold_assert(loccount == symtabshdr.get_sh_info());
6394 off_t locsize = loccount * sym_size;
6395 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6396 locsize, true, true);
6398 // Process the deferred EXIDX sections.
6399 for(unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6401 unsigned int shndx = deferred_exidx_sections[i];
6402 elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6403 unsigned int text_shndx;
6404 Reloc_map::const_iterator it = reloc_map.find(shndx);
6405 if (it != reloc_map.end()
6406 && find_linked_text_section(pshdrs + it->second * shdr_size,
6407 psyms, &text_shndx))
6408 this->make_exidx_input_section(shndx, shdr, text_shndx);
6409 else
6410 gold_error(_("EXIDX section %u has no linked text section."),
6411 shndx);
6416 // Process relocations for garbage collection. The ARM target uses .ARM.exidx
6417 // sections for unwinding. These sections are referenced implicitly by
6418 // text sections linked in the section headers. If we ignore these implict
6419 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6420 // will be garbage-collected incorrectly. Hence we override the same function
6421 // in the base class to handle these implicit references.
6423 template<bool big_endian>
6424 void
6425 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6426 Layout* layout,
6427 Read_relocs_data* rd)
6429 // First, call base class method to process relocations in this object.
6430 Sized_relobj<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6432 // If --gc-sections is not specified, there is nothing more to do.
6433 // This happens when --icf is used but --gc-sections is not.
6434 if (!parameters->options().gc_sections())
6435 return;
6437 unsigned int shnum = this->shnum();
6438 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6439 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6440 shnum * shdr_size,
6441 true, true);
6443 // Scan section headers for sections of type SHT_ARM_EXIDX. Add references
6444 // to these from the linked text sections.
6445 const unsigned char* ps = pshdrs + shdr_size;
6446 for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6448 elfcpp::Shdr<32, big_endian> shdr(ps);
6449 if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6451 // Found an .ARM.exidx section, add it to the set of reachable
6452 // sections from its linked text section.
6453 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6454 symtab->gc()->add_reference(this, text_shndx, this, i);
6459 // Update output local symbol count. Owing to EXIDX entry merging, some local
6460 // symbols will be removed in output. Adjust output local symbol count
6461 // accordingly. We can only changed the static output local symbol count. It
6462 // is too late to change the dynamic symbols.
6464 template<bool big_endian>
6465 void
6466 Arm_relobj<big_endian>::update_output_local_symbol_count()
6468 // Caller should check that this needs updating. We want caller checking
6469 // because output_local_symbol_count_needs_update() is most likely inlined.
6470 gold_assert(this->output_local_symbol_count_needs_update_);
6472 gold_assert(this->symtab_shndx() != -1U);
6473 if (this->symtab_shndx() == 0)
6475 // This object has no symbols. Weird but legal.
6476 return;
6479 // Read the symbol table section header.
6480 const unsigned int symtab_shndx = this->symtab_shndx();
6481 elfcpp::Shdr<32, big_endian>
6482 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6483 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6485 // Read the local symbols.
6486 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6487 const unsigned int loccount = this->local_symbol_count();
6488 gold_assert(loccount == symtabshdr.get_sh_info());
6489 off_t locsize = loccount * sym_size;
6490 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6491 locsize, true, true);
6493 // Loop over the local symbols.
6495 typedef typename Sized_relobj<32, big_endian>::Output_sections
6496 Output_sections;
6497 const Output_sections& out_sections(this->output_sections());
6498 unsigned int shnum = this->shnum();
6499 unsigned int count = 0;
6500 // Skip the first, dummy, symbol.
6501 psyms += sym_size;
6502 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6504 elfcpp::Sym<32, big_endian> sym(psyms);
6506 Symbol_value<32>& lv((*this->local_values())[i]);
6508 // This local symbol was already discarded by do_count_local_symbols.
6509 if (!lv.is_output_symtab_index_set())
6510 continue;
6512 bool is_ordinary;
6513 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6514 &is_ordinary);
6516 if (shndx < shnum)
6518 Output_section* os = out_sections[shndx];
6520 // This local symbol no longer has an output section. Discard it.
6521 if (os == NULL)
6523 lv.set_no_output_symtab_entry();
6524 continue;
6527 // Currently we only discard parts of EXIDX input sections.
6528 // We explicitly check for a merged EXIDX input section to avoid
6529 // calling Output_section_data::output_offset unless necessary.
6530 if ((this->get_output_section_offset(shndx) == invalid_address)
6531 && (this->exidx_input_section_by_shndx(shndx) != NULL))
6533 section_offset_type output_offset =
6534 os->output_offset(this, shndx, lv.input_value());
6535 if (output_offset == -1)
6537 // This symbol is defined in a part of an EXIDX input section
6538 // that is discarded due to entry merging.
6539 lv.set_no_output_symtab_entry();
6540 continue;
6545 ++count;
6548 this->set_output_local_symbol_count(count);
6549 this->output_local_symbol_count_needs_update_ = false;
6552 // Arm_dynobj methods.
6554 // Read the symbol information.
6556 template<bool big_endian>
6557 void
6558 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6560 // Call parent class to read symbol information.
6561 Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6563 // Read processor-specific flags in ELF file header.
6564 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6565 elfcpp::Elf_sizes<32>::ehdr_size,
6566 true, false);
6567 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6568 this->processor_specific_flags_ = ehdr.get_e_flags();
6570 // Read the attributes section if there is one.
6571 // We read from the end because gas seems to put it near the end of
6572 // the section headers.
6573 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6574 const unsigned char *ps =
6575 sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6576 for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6578 elfcpp::Shdr<32, big_endian> shdr(ps);
6579 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6581 section_offset_type section_offset = shdr.get_sh_offset();
6582 section_size_type section_size =
6583 convert_to_section_size_type(shdr.get_sh_size());
6584 File_view* view = this->get_lasting_view(section_offset,
6585 section_size, true, false);
6586 this->attributes_section_data_ =
6587 new Attributes_section_data(view->data(), section_size);
6588 break;
6593 // Stub_addend_reader methods.
6595 // Read the addend of a REL relocation of type R_TYPE at VIEW.
6597 template<bool big_endian>
6598 elfcpp::Elf_types<32>::Elf_Swxword
6599 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
6600 unsigned int r_type,
6601 const unsigned char* view,
6602 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
6604 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
6606 switch (r_type)
6608 case elfcpp::R_ARM_CALL:
6609 case elfcpp::R_ARM_JUMP24:
6610 case elfcpp::R_ARM_PLT32:
6612 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
6613 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6614 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
6615 return utils::sign_extend<26>(val << 2);
6618 case elfcpp::R_ARM_THM_CALL:
6619 case elfcpp::R_ARM_THM_JUMP24:
6620 case elfcpp::R_ARM_THM_XPC22:
6622 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
6623 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6624 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
6625 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
6626 return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
6629 case elfcpp::R_ARM_THM_JUMP19:
6631 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
6632 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6633 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
6634 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
6635 return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
6638 default:
6639 gold_unreachable();
6643 // Arm_output_data_got methods.
6645 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
6646 // The first one is initialized to be 1, which is the module index for
6647 // the main executable and the second one 0. A reloc of the type
6648 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
6649 // be applied by gold. GSYM is a global symbol.
6651 template<bool big_endian>
6652 void
6653 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
6654 unsigned int got_type,
6655 Symbol* gsym)
6657 if (gsym->has_got_offset(got_type))
6658 return;
6660 // We are doing a static link. Just mark it as belong to module 1,
6661 // the executable.
6662 unsigned int got_offset = this->add_constant(1);
6663 gsym->set_got_offset(got_type, got_offset);
6664 got_offset = this->add_constant(0);
6665 this->static_relocs_.push_back(Static_reloc(got_offset,
6666 elfcpp::R_ARM_TLS_DTPOFF32,
6667 gsym));
6670 // Same as the above but for a local symbol.
6672 template<bool big_endian>
6673 void
6674 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
6675 unsigned int got_type,
6676 Sized_relobj<32, big_endian>* object,
6677 unsigned int index)
6679 if (object->local_has_got_offset(index, got_type))
6680 return;
6682 // We are doing a static link. Just mark it as belong to module 1,
6683 // the executable.
6684 unsigned int got_offset = this->add_constant(1);
6685 object->set_local_got_offset(index, got_type, got_offset);
6686 got_offset = this->add_constant(0);
6687 this->static_relocs_.push_back(Static_reloc(got_offset,
6688 elfcpp::R_ARM_TLS_DTPOFF32,
6689 object, index));
6692 template<bool big_endian>
6693 void
6694 Arm_output_data_got<big_endian>::do_write(Output_file* of)
6696 // Call parent to write out GOT.
6697 Output_data_got<32, big_endian>::do_write(of);
6699 // We are done if there is no fix up.
6700 if (this->static_relocs_.empty())
6701 return;
6703 gold_assert(parameters->doing_static_link());
6705 const off_t offset = this->offset();
6706 const section_size_type oview_size =
6707 convert_to_section_size_type(this->data_size());
6708 unsigned char* const oview = of->get_output_view(offset, oview_size);
6710 Output_segment* tls_segment = this->layout_->tls_segment();
6711 gold_assert(tls_segment != NULL);
6713 // The thread pointer $tp points to the TCB, which is followed by the
6714 // TLS. So we need to adjust $tp relative addressing by this amount.
6715 Arm_address aligned_tcb_size =
6716 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
6718 for (size_t i = 0; i < this->static_relocs_.size(); ++i)
6720 Static_reloc& reloc(this->static_relocs_[i]);
6722 Arm_address value;
6723 if (!reloc.symbol_is_global())
6725 Sized_relobj<32, big_endian>* object = reloc.relobj();
6726 const Symbol_value<32>* psymval =
6727 reloc.relobj()->local_symbol(reloc.index());
6729 // We are doing static linking. Issue an error and skip this
6730 // relocation if the symbol is undefined or in a discarded_section.
6731 bool is_ordinary;
6732 unsigned int shndx = psymval->input_shndx(&is_ordinary);
6733 if ((shndx == elfcpp::SHN_UNDEF)
6734 || (is_ordinary
6735 && shndx != elfcpp::SHN_UNDEF
6736 && !object->is_section_included(shndx)
6737 && !this->symbol_table_->is_section_folded(object, shndx)))
6739 gold_error(_("undefined or discarded local symbol %u from "
6740 " object %s in GOT"),
6741 reloc.index(), reloc.relobj()->name().c_str());
6742 continue;
6745 value = psymval->value(object, 0);
6747 else
6749 const Symbol* gsym = reloc.symbol();
6750 gold_assert(gsym != NULL);
6751 if (gsym->is_forwarder())
6752 gsym = this->symbol_table_->resolve_forwards(gsym);
6754 // We are doing static linking. Issue an error and skip this
6755 // relocation if the symbol is undefined or in a discarded_section
6756 // unless it is a weakly_undefined symbol.
6757 if ((gsym->is_defined_in_discarded_section()
6758 || gsym->is_undefined())
6759 && !gsym->is_weak_undefined())
6761 gold_error(_("undefined or discarded symbol %s in GOT"),
6762 gsym->name());
6763 continue;
6766 if (!gsym->is_weak_undefined())
6768 const Sized_symbol<32>* sym =
6769 static_cast<const Sized_symbol<32>*>(gsym);
6770 value = sym->value();
6772 else
6773 value = 0;
6776 unsigned got_offset = reloc.got_offset();
6777 gold_assert(got_offset < oview_size);
6779 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
6780 Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
6781 Valtype x;
6782 switch (reloc.r_type())
6784 case elfcpp::R_ARM_TLS_DTPOFF32:
6785 x = value;
6786 break;
6787 case elfcpp::R_ARM_TLS_TPOFF32:
6788 x = value + aligned_tcb_size;
6789 break;
6790 default:
6791 gold_unreachable();
6793 elfcpp::Swap<32, big_endian>::writeval(wv, x);
6796 of->write_output_view(offset, oview_size, oview);
6799 // A class to handle the PLT data.
6801 template<bool big_endian>
6802 class Output_data_plt_arm : public Output_section_data
6804 public:
6805 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
6806 Reloc_section;
6808 Output_data_plt_arm(Layout*, Output_data_space*);
6810 // Add an entry to the PLT.
6811 void
6812 add_entry(Symbol* gsym);
6814 // Return the .rel.plt section data.
6815 const Reloc_section*
6816 rel_plt() const
6817 { return this->rel_; }
6819 protected:
6820 void
6821 do_adjust_output_section(Output_section* os);
6823 // Write to a map file.
6824 void
6825 do_print_to_mapfile(Mapfile* mapfile) const
6826 { mapfile->print_output_data(this, _("** PLT")); }
6828 private:
6829 // Template for the first PLT entry.
6830 static const uint32_t first_plt_entry[5];
6832 // Template for subsequent PLT entries.
6833 static const uint32_t plt_entry[3];
6835 // Set the final size.
6836 void
6837 set_final_data_size()
6839 this->set_data_size(sizeof(first_plt_entry)
6840 + this->count_ * sizeof(plt_entry));
6843 // Write out the PLT data.
6844 void
6845 do_write(Output_file*);
6847 // The reloc section.
6848 Reloc_section* rel_;
6849 // The .got.plt section.
6850 Output_data_space* got_plt_;
6851 // The number of PLT entries.
6852 unsigned int count_;
6855 // Create the PLT section. The ordinary .got section is an argument,
6856 // since we need to refer to the start. We also create our own .got
6857 // section just for PLT entries.
6859 template<bool big_endian>
6860 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
6861 Output_data_space* got_plt)
6862 : Output_section_data(4), got_plt_(got_plt), count_(0)
6864 this->rel_ = new Reloc_section(false);
6865 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
6866 elfcpp::SHF_ALLOC, this->rel_, true, false,
6867 false, false);
6870 template<bool big_endian>
6871 void
6872 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
6874 os->set_entsize(0);
6877 // Add an entry to the PLT.
6879 template<bool big_endian>
6880 void
6881 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
6883 gold_assert(!gsym->has_plt_offset());
6885 // Note that when setting the PLT offset we skip the initial
6886 // reserved PLT entry.
6887 gsym->set_plt_offset((this->count_) * sizeof(plt_entry)
6888 + sizeof(first_plt_entry));
6890 ++this->count_;
6892 section_offset_type got_offset = this->got_plt_->current_data_size();
6894 // Every PLT entry needs a GOT entry which points back to the PLT
6895 // entry (this will be changed by the dynamic linker, normally
6896 // lazily when the function is called).
6897 this->got_plt_->set_current_data_size(got_offset + 4);
6899 // Every PLT entry needs a reloc.
6900 gsym->set_needs_dynsym_entry();
6901 this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
6902 got_offset);
6904 // Note that we don't need to save the symbol. The contents of the
6905 // PLT are independent of which symbols are used. The symbols only
6906 // appear in the relocations.
6909 // ARM PLTs.
6910 // FIXME: This is not very flexible. Right now this has only been tested
6911 // on armv5te. If we are to support additional architecture features like
6912 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
6914 // The first entry in the PLT.
6915 template<bool big_endian>
6916 const uint32_t Output_data_plt_arm<big_endian>::first_plt_entry[5] =
6918 0xe52de004, // str lr, [sp, #-4]!
6919 0xe59fe004, // ldr lr, [pc, #4]
6920 0xe08fe00e, // add lr, pc, lr
6921 0xe5bef008, // ldr pc, [lr, #8]!
6922 0x00000000, // &GOT[0] - .
6925 // Subsequent entries in the PLT.
6927 template<bool big_endian>
6928 const uint32_t Output_data_plt_arm<big_endian>::plt_entry[3] =
6930 0xe28fc600, // add ip, pc, #0xNN00000
6931 0xe28cca00, // add ip, ip, #0xNN000
6932 0xe5bcf000, // ldr pc, [ip, #0xNNN]!
6935 // Write out the PLT. This uses the hand-coded instructions above,
6936 // and adjusts them as needed. This is all specified by the arm ELF
6937 // Processor Supplement.
6939 template<bool big_endian>
6940 void
6941 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
6943 const off_t offset = this->offset();
6944 const section_size_type oview_size =
6945 convert_to_section_size_type(this->data_size());
6946 unsigned char* const oview = of->get_output_view(offset, oview_size);
6948 const off_t got_file_offset = this->got_plt_->offset();
6949 const section_size_type got_size =
6950 convert_to_section_size_type(this->got_plt_->data_size());
6951 unsigned char* const got_view = of->get_output_view(got_file_offset,
6952 got_size);
6953 unsigned char* pov = oview;
6955 Arm_address plt_address = this->address();
6956 Arm_address got_address = this->got_plt_->address();
6958 // Write first PLT entry. All but the last word are constants.
6959 const size_t num_first_plt_words = (sizeof(first_plt_entry)
6960 / sizeof(plt_entry[0]));
6961 for (size_t i = 0; i < num_first_plt_words - 1; i++)
6962 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
6963 // Last word in first PLT entry is &GOT[0] - .
6964 elfcpp::Swap<32, big_endian>::writeval(pov + 16,
6965 got_address - (plt_address + 16));
6966 pov += sizeof(first_plt_entry);
6968 unsigned char* got_pov = got_view;
6970 memset(got_pov, 0, 12);
6971 got_pov += 12;
6973 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
6974 unsigned int plt_offset = sizeof(first_plt_entry);
6975 unsigned int plt_rel_offset = 0;
6976 unsigned int got_offset = 12;
6977 const unsigned int count = this->count_;
6978 for (unsigned int i = 0;
6979 i < count;
6980 ++i,
6981 pov += sizeof(plt_entry),
6982 got_pov += 4,
6983 plt_offset += sizeof(plt_entry),
6984 plt_rel_offset += rel_size,
6985 got_offset += 4)
6987 // Set and adjust the PLT entry itself.
6988 int32_t offset = ((got_address + got_offset)
6989 - (plt_address + plt_offset + 8));
6991 gold_assert(offset >= 0 && offset < 0x0fffffff);
6992 uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
6993 elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
6994 uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
6995 elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
6996 uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
6997 elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
6999 // Set the entry in the GOT.
7000 elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7003 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7004 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7006 of->write_output_view(offset, oview_size, oview);
7007 of->write_output_view(got_file_offset, got_size, got_view);
7010 // Create a PLT entry for a global symbol.
7012 template<bool big_endian>
7013 void
7014 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7015 Symbol* gsym)
7017 if (gsym->has_plt_offset())
7018 return;
7020 if (this->plt_ == NULL)
7022 // Create the GOT sections first.
7023 this->got_section(symtab, layout);
7025 this->plt_ = new Output_data_plt_arm<big_endian>(layout, this->got_plt_);
7026 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7027 (elfcpp::SHF_ALLOC
7028 | elfcpp::SHF_EXECINSTR),
7029 this->plt_, false, false, false, false);
7031 this->plt_->add_entry(gsym);
7034 // Get the section to use for TLS_DESC relocations.
7036 template<bool big_endian>
7037 typename Target_arm<big_endian>::Reloc_section*
7038 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7040 return this->plt_section()->rel_tls_desc(layout);
7043 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7045 template<bool big_endian>
7046 void
7047 Target_arm<big_endian>::define_tls_base_symbol(
7048 Symbol_table* symtab,
7049 Layout* layout)
7051 if (this->tls_base_symbol_defined_)
7052 return;
7054 Output_segment* tls_segment = layout->tls_segment();
7055 if (tls_segment != NULL)
7057 bool is_exec = parameters->options().output_is_executable();
7058 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7059 Symbol_table::PREDEFINED,
7060 tls_segment, 0, 0,
7061 elfcpp::STT_TLS,
7062 elfcpp::STB_LOCAL,
7063 elfcpp::STV_HIDDEN, 0,
7064 (is_exec
7065 ? Symbol::SEGMENT_END
7066 : Symbol::SEGMENT_START),
7067 true);
7069 this->tls_base_symbol_defined_ = true;
7072 // Create a GOT entry for the TLS module index.
7074 template<bool big_endian>
7075 unsigned int
7076 Target_arm<big_endian>::got_mod_index_entry(
7077 Symbol_table* symtab,
7078 Layout* layout,
7079 Sized_relobj<32, big_endian>* object)
7081 if (this->got_mod_index_offset_ == -1U)
7083 gold_assert(symtab != NULL && layout != NULL && object != NULL);
7084 Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7085 unsigned int got_offset;
7086 if (!parameters->doing_static_link())
7088 got_offset = got->add_constant(0);
7089 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7090 rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7091 got_offset);
7093 else
7095 // We are doing a static link. Just mark it as belong to module 1,
7096 // the executable.
7097 got_offset = got->add_constant(1);
7100 got->add_constant(0);
7101 this->got_mod_index_offset_ = got_offset;
7103 return this->got_mod_index_offset_;
7106 // Optimize the TLS relocation type based on what we know about the
7107 // symbol. IS_FINAL is true if the final address of this symbol is
7108 // known at link time.
7110 template<bool big_endian>
7111 tls::Tls_optimization
7112 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7114 // FIXME: Currently we do not do any TLS optimization.
7115 return tls::TLSOPT_NONE;
7118 // Report an unsupported relocation against a local symbol.
7120 template<bool big_endian>
7121 void
7122 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7123 Sized_relobj<32, big_endian>* object,
7124 unsigned int r_type)
7126 gold_error(_("%s: unsupported reloc %u against local symbol"),
7127 object->name().c_str(), r_type);
7130 // We are about to emit a dynamic relocation of type R_TYPE. If the
7131 // dynamic linker does not support it, issue an error. The GNU linker
7132 // only issues a non-PIC error for an allocated read-only section.
7133 // Here we know the section is allocated, but we don't know that it is
7134 // read-only. But we check for all the relocation types which the
7135 // glibc dynamic linker supports, so it seems appropriate to issue an
7136 // error even if the section is not read-only.
7138 template<bool big_endian>
7139 void
7140 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7141 unsigned int r_type)
7143 switch (r_type)
7145 // These are the relocation types supported by glibc for ARM.
7146 case elfcpp::R_ARM_RELATIVE:
7147 case elfcpp::R_ARM_COPY:
7148 case elfcpp::R_ARM_GLOB_DAT:
7149 case elfcpp::R_ARM_JUMP_SLOT:
7150 case elfcpp::R_ARM_ABS32:
7151 case elfcpp::R_ARM_ABS32_NOI:
7152 case elfcpp::R_ARM_PC24:
7153 // FIXME: The following 3 types are not supported by Android's dynamic
7154 // linker.
7155 case elfcpp::R_ARM_TLS_DTPMOD32:
7156 case elfcpp::R_ARM_TLS_DTPOFF32:
7157 case elfcpp::R_ARM_TLS_TPOFF32:
7158 return;
7160 default:
7162 // This prevents us from issuing more than one error per reloc
7163 // section. But we can still wind up issuing more than one
7164 // error per object file.
7165 if (this->issued_non_pic_error_)
7166 return;
7167 const Arm_reloc_property* reloc_property =
7168 arm_reloc_property_table->get_reloc_property(r_type);
7169 gold_assert(reloc_property != NULL);
7170 object->error(_("requires unsupported dynamic reloc %s; "
7171 "recompile with -fPIC"),
7172 reloc_property->name().c_str());
7173 this->issued_non_pic_error_ = true;
7174 return;
7177 case elfcpp::R_ARM_NONE:
7178 gold_unreachable();
7182 // Scan a relocation for a local symbol.
7183 // FIXME: This only handles a subset of relocation types used by Android
7184 // on ARM v5te devices.
7186 template<bool big_endian>
7187 inline void
7188 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7189 Layout* layout,
7190 Target_arm* target,
7191 Sized_relobj<32, big_endian>* object,
7192 unsigned int data_shndx,
7193 Output_section* output_section,
7194 const elfcpp::Rel<32, big_endian>& reloc,
7195 unsigned int r_type,
7196 const elfcpp::Sym<32, big_endian>& lsym)
7198 r_type = get_real_reloc_type(r_type);
7199 switch (r_type)
7201 case elfcpp::R_ARM_NONE:
7202 case elfcpp::R_ARM_V4BX:
7203 case elfcpp::R_ARM_GNU_VTENTRY:
7204 case elfcpp::R_ARM_GNU_VTINHERIT:
7205 break;
7207 case elfcpp::R_ARM_ABS32:
7208 case elfcpp::R_ARM_ABS32_NOI:
7209 // If building a shared library (or a position-independent
7210 // executable), we need to create a dynamic relocation for
7211 // this location. The relocation applied at link time will
7212 // apply the link-time value, so we flag the location with
7213 // an R_ARM_RELATIVE relocation so the dynamic loader can
7214 // relocate it easily.
7215 if (parameters->options().output_is_position_independent())
7217 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7218 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7219 // If we are to add more other reloc types than R_ARM_ABS32,
7220 // we need to add check_non_pic(object, r_type) here.
7221 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7222 output_section, data_shndx,
7223 reloc.get_r_offset());
7225 break;
7227 case elfcpp::R_ARM_ABS16:
7228 case elfcpp::R_ARM_ABS12:
7229 case elfcpp::R_ARM_THM_ABS5:
7230 case elfcpp::R_ARM_ABS8:
7231 case elfcpp::R_ARM_BASE_ABS:
7232 case elfcpp::R_ARM_MOVW_ABS_NC:
7233 case elfcpp::R_ARM_MOVT_ABS:
7234 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7235 case elfcpp::R_ARM_THM_MOVT_ABS:
7236 // If building a shared library (or a position-independent
7237 // executable), we need to create a dynamic relocation for
7238 // this location. Because the addend needs to remain in the
7239 // data section, we need to be careful not to apply this
7240 // relocation statically.
7241 if (parameters->options().output_is_position_independent())
7243 check_non_pic(object, r_type);
7244 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7245 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7246 if (lsym.get_st_type() != elfcpp::STT_SECTION)
7247 rel_dyn->add_local(object, r_sym, r_type, output_section,
7248 data_shndx, reloc.get_r_offset());
7249 else
7251 gold_assert(lsym.get_st_value() == 0);
7252 unsigned int shndx = lsym.get_st_shndx();
7253 bool is_ordinary;
7254 shndx = object->adjust_sym_shndx(r_sym, shndx,
7255 &is_ordinary);
7256 if (!is_ordinary)
7257 object->error(_("section symbol %u has bad shndx %u"),
7258 r_sym, shndx);
7259 else
7260 rel_dyn->add_local_section(object, shndx,
7261 r_type, output_section,
7262 data_shndx, reloc.get_r_offset());
7265 break;
7267 case elfcpp::R_ARM_PC24:
7268 case elfcpp::R_ARM_REL32:
7269 case elfcpp::R_ARM_LDR_PC_G0:
7270 case elfcpp::R_ARM_SBREL32:
7271 case elfcpp::R_ARM_THM_CALL:
7272 case elfcpp::R_ARM_THM_PC8:
7273 case elfcpp::R_ARM_BASE_PREL:
7274 case elfcpp::R_ARM_PLT32:
7275 case elfcpp::R_ARM_CALL:
7276 case elfcpp::R_ARM_JUMP24:
7277 case elfcpp::R_ARM_THM_JUMP24:
7278 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7279 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7280 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7281 case elfcpp::R_ARM_SBREL31:
7282 case elfcpp::R_ARM_PREL31:
7283 case elfcpp::R_ARM_MOVW_PREL_NC:
7284 case elfcpp::R_ARM_MOVT_PREL:
7285 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7286 case elfcpp::R_ARM_THM_MOVT_PREL:
7287 case elfcpp::R_ARM_THM_JUMP19:
7288 case elfcpp::R_ARM_THM_JUMP6:
7289 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7290 case elfcpp::R_ARM_THM_PC12:
7291 case elfcpp::R_ARM_REL32_NOI:
7292 case elfcpp::R_ARM_ALU_PC_G0_NC:
7293 case elfcpp::R_ARM_ALU_PC_G0:
7294 case elfcpp::R_ARM_ALU_PC_G1_NC:
7295 case elfcpp::R_ARM_ALU_PC_G1:
7296 case elfcpp::R_ARM_ALU_PC_G2:
7297 case elfcpp::R_ARM_LDR_PC_G1:
7298 case elfcpp::R_ARM_LDR_PC_G2:
7299 case elfcpp::R_ARM_LDRS_PC_G0:
7300 case elfcpp::R_ARM_LDRS_PC_G1:
7301 case elfcpp::R_ARM_LDRS_PC_G2:
7302 case elfcpp::R_ARM_LDC_PC_G0:
7303 case elfcpp::R_ARM_LDC_PC_G1:
7304 case elfcpp::R_ARM_LDC_PC_G2:
7305 case elfcpp::R_ARM_ALU_SB_G0_NC:
7306 case elfcpp::R_ARM_ALU_SB_G0:
7307 case elfcpp::R_ARM_ALU_SB_G1_NC:
7308 case elfcpp::R_ARM_ALU_SB_G1:
7309 case elfcpp::R_ARM_ALU_SB_G2:
7310 case elfcpp::R_ARM_LDR_SB_G0:
7311 case elfcpp::R_ARM_LDR_SB_G1:
7312 case elfcpp::R_ARM_LDR_SB_G2:
7313 case elfcpp::R_ARM_LDRS_SB_G0:
7314 case elfcpp::R_ARM_LDRS_SB_G1:
7315 case elfcpp::R_ARM_LDRS_SB_G2:
7316 case elfcpp::R_ARM_LDC_SB_G0:
7317 case elfcpp::R_ARM_LDC_SB_G1:
7318 case elfcpp::R_ARM_LDC_SB_G2:
7319 case elfcpp::R_ARM_MOVW_BREL_NC:
7320 case elfcpp::R_ARM_MOVT_BREL:
7321 case elfcpp::R_ARM_MOVW_BREL:
7322 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7323 case elfcpp::R_ARM_THM_MOVT_BREL:
7324 case elfcpp::R_ARM_THM_MOVW_BREL:
7325 case elfcpp::R_ARM_THM_JUMP11:
7326 case elfcpp::R_ARM_THM_JUMP8:
7327 // We don't need to do anything for a relative addressing relocation
7328 // against a local symbol if it does not reference the GOT.
7329 break;
7331 case elfcpp::R_ARM_GOTOFF32:
7332 case elfcpp::R_ARM_GOTOFF12:
7333 // We need a GOT section:
7334 target->got_section(symtab, layout);
7335 break;
7337 case elfcpp::R_ARM_GOT_BREL:
7338 case elfcpp::R_ARM_GOT_PREL:
7340 // The symbol requires a GOT entry.
7341 Arm_output_data_got<big_endian>* got =
7342 target->got_section(symtab, layout);
7343 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7344 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
7346 // If we are generating a shared object, we need to add a
7347 // dynamic RELATIVE relocation for this symbol's GOT entry.
7348 if (parameters->options().output_is_position_independent())
7350 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7351 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7352 rel_dyn->add_local_relative(
7353 object, r_sym, elfcpp::R_ARM_RELATIVE, got,
7354 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
7358 break;
7360 case elfcpp::R_ARM_TARGET1:
7361 case elfcpp::R_ARM_TARGET2:
7362 // This should have been mapped to another type already.
7363 // Fall through.
7364 case elfcpp::R_ARM_COPY:
7365 case elfcpp::R_ARM_GLOB_DAT:
7366 case elfcpp::R_ARM_JUMP_SLOT:
7367 case elfcpp::R_ARM_RELATIVE:
7368 // These are relocations which should only be seen by the
7369 // dynamic linker, and should never be seen here.
7370 gold_error(_("%s: unexpected reloc %u in object file"),
7371 object->name().c_str(), r_type);
7372 break;
7375 // These are initial TLS relocs, which are expected when
7376 // linking.
7377 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7378 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7379 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7380 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7381 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7383 bool output_is_shared = parameters->options().shared();
7384 const tls::Tls_optimization optimized_type
7385 = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
7386 r_type);
7387 switch (r_type)
7389 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7390 if (optimized_type == tls::TLSOPT_NONE)
7392 // Create a pair of GOT entries for the module index and
7393 // dtv-relative offset.
7394 Arm_output_data_got<big_endian>* got
7395 = target->got_section(symtab, layout);
7396 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7397 unsigned int shndx = lsym.get_st_shndx();
7398 bool is_ordinary;
7399 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
7400 if (!is_ordinary)
7402 object->error(_("local symbol %u has bad shndx %u"),
7403 r_sym, shndx);
7404 break;
7407 if (!parameters->doing_static_link())
7408 got->add_local_pair_with_rel(object, r_sym, shndx,
7409 GOT_TYPE_TLS_PAIR,
7410 target->rel_dyn_section(layout),
7411 elfcpp::R_ARM_TLS_DTPMOD32, 0);
7412 else
7413 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
7414 object, r_sym);
7416 else
7417 // FIXME: TLS optimization not supported yet.
7418 gold_unreachable();
7419 break;
7421 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7422 if (optimized_type == tls::TLSOPT_NONE)
7424 // Create a GOT entry for the module index.
7425 target->got_mod_index_entry(symtab, layout, object);
7427 else
7428 // FIXME: TLS optimization not supported yet.
7429 gold_unreachable();
7430 break;
7432 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7433 break;
7435 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7436 layout->set_has_static_tls();
7437 if (optimized_type == tls::TLSOPT_NONE)
7439 // Create a GOT entry for the tp-relative offset.
7440 Arm_output_data_got<big_endian>* got
7441 = target->got_section(symtab, layout);
7442 unsigned int r_sym =
7443 elfcpp::elf_r_sym<32>(reloc.get_r_info());
7444 if (!parameters->doing_static_link())
7445 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
7446 target->rel_dyn_section(layout),
7447 elfcpp::R_ARM_TLS_TPOFF32);
7448 else if (!object->local_has_got_offset(r_sym,
7449 GOT_TYPE_TLS_OFFSET))
7451 got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
7452 unsigned int got_offset =
7453 object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
7454 got->add_static_reloc(got_offset,
7455 elfcpp::R_ARM_TLS_TPOFF32, object,
7456 r_sym);
7459 else
7460 // FIXME: TLS optimization not supported yet.
7461 gold_unreachable();
7462 break;
7464 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7465 layout->set_has_static_tls();
7466 if (output_is_shared)
7468 // We need to create a dynamic relocation.
7469 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
7470 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7471 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7472 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
7473 output_section, data_shndx,
7474 reloc.get_r_offset());
7476 break;
7478 default:
7479 gold_unreachable();
7482 break;
7484 default:
7485 unsupported_reloc_local(object, r_type);
7486 break;
7490 // Report an unsupported relocation against a global symbol.
7492 template<bool big_endian>
7493 void
7494 Target_arm<big_endian>::Scan::unsupported_reloc_global(
7495 Sized_relobj<32, big_endian>* object,
7496 unsigned int r_type,
7497 Symbol* gsym)
7499 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
7500 object->name().c_str(), r_type, gsym->demangled_name().c_str());
7503 // Scan a relocation for a global symbol.
7505 template<bool big_endian>
7506 inline void
7507 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
7508 Layout* layout,
7509 Target_arm* target,
7510 Sized_relobj<32, big_endian>* object,
7511 unsigned int data_shndx,
7512 Output_section* output_section,
7513 const elfcpp::Rel<32, big_endian>& reloc,
7514 unsigned int r_type,
7515 Symbol* gsym)
7517 // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
7518 // section. We check here to avoid creating a dynamic reloc against
7519 // _GLOBAL_OFFSET_TABLE_.
7520 if (!target->has_got_section()
7521 && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
7522 target->got_section(symtab, layout);
7524 r_type = get_real_reloc_type(r_type);
7525 switch (r_type)
7527 case elfcpp::R_ARM_NONE:
7528 case elfcpp::R_ARM_V4BX:
7529 case elfcpp::R_ARM_GNU_VTENTRY:
7530 case elfcpp::R_ARM_GNU_VTINHERIT:
7531 break;
7533 case elfcpp::R_ARM_ABS32:
7534 case elfcpp::R_ARM_ABS16:
7535 case elfcpp::R_ARM_ABS12:
7536 case elfcpp::R_ARM_THM_ABS5:
7537 case elfcpp::R_ARM_ABS8:
7538 case elfcpp::R_ARM_BASE_ABS:
7539 case elfcpp::R_ARM_MOVW_ABS_NC:
7540 case elfcpp::R_ARM_MOVT_ABS:
7541 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7542 case elfcpp::R_ARM_THM_MOVT_ABS:
7543 case elfcpp::R_ARM_ABS32_NOI:
7544 // Absolute addressing relocations.
7546 // Make a PLT entry if necessary.
7547 if (this->symbol_needs_plt_entry(gsym))
7549 target->make_plt_entry(symtab, layout, gsym);
7550 // Since this is not a PC-relative relocation, we may be
7551 // taking the address of a function. In that case we need to
7552 // set the entry in the dynamic symbol table to the address of
7553 // the PLT entry.
7554 if (gsym->is_from_dynobj() && !parameters->options().shared())
7555 gsym->set_needs_dynsym_value();
7557 // Make a dynamic relocation if necessary.
7558 if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
7560 if (gsym->may_need_copy_reloc())
7562 target->copy_reloc(symtab, layout, object,
7563 data_shndx, output_section, gsym, reloc);
7565 else if ((r_type == elfcpp::R_ARM_ABS32
7566 || r_type == elfcpp::R_ARM_ABS32_NOI)
7567 && gsym->can_use_relative_reloc(false))
7569 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7570 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
7571 output_section, object,
7572 data_shndx, reloc.get_r_offset());
7574 else
7576 check_non_pic(object, r_type);
7577 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7578 rel_dyn->add_global(gsym, r_type, output_section, object,
7579 data_shndx, reloc.get_r_offset());
7583 break;
7585 case elfcpp::R_ARM_GOTOFF32:
7586 case elfcpp::R_ARM_GOTOFF12:
7587 // We need a GOT section.
7588 target->got_section(symtab, layout);
7589 break;
7591 case elfcpp::R_ARM_REL32:
7592 case elfcpp::R_ARM_LDR_PC_G0:
7593 case elfcpp::R_ARM_SBREL32:
7594 case elfcpp::R_ARM_THM_PC8:
7595 case elfcpp::R_ARM_BASE_PREL:
7596 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7597 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7598 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7599 case elfcpp::R_ARM_MOVW_PREL_NC:
7600 case elfcpp::R_ARM_MOVT_PREL:
7601 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7602 case elfcpp::R_ARM_THM_MOVT_PREL:
7603 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7604 case elfcpp::R_ARM_THM_PC12:
7605 case elfcpp::R_ARM_REL32_NOI:
7606 case elfcpp::R_ARM_ALU_PC_G0_NC:
7607 case elfcpp::R_ARM_ALU_PC_G0:
7608 case elfcpp::R_ARM_ALU_PC_G1_NC:
7609 case elfcpp::R_ARM_ALU_PC_G1:
7610 case elfcpp::R_ARM_ALU_PC_G2:
7611 case elfcpp::R_ARM_LDR_PC_G1:
7612 case elfcpp::R_ARM_LDR_PC_G2:
7613 case elfcpp::R_ARM_LDRS_PC_G0:
7614 case elfcpp::R_ARM_LDRS_PC_G1:
7615 case elfcpp::R_ARM_LDRS_PC_G2:
7616 case elfcpp::R_ARM_LDC_PC_G0:
7617 case elfcpp::R_ARM_LDC_PC_G1:
7618 case elfcpp::R_ARM_LDC_PC_G2:
7619 case elfcpp::R_ARM_ALU_SB_G0_NC:
7620 case elfcpp::R_ARM_ALU_SB_G0:
7621 case elfcpp::R_ARM_ALU_SB_G1_NC:
7622 case elfcpp::R_ARM_ALU_SB_G1:
7623 case elfcpp::R_ARM_ALU_SB_G2:
7624 case elfcpp::R_ARM_LDR_SB_G0:
7625 case elfcpp::R_ARM_LDR_SB_G1:
7626 case elfcpp::R_ARM_LDR_SB_G2:
7627 case elfcpp::R_ARM_LDRS_SB_G0:
7628 case elfcpp::R_ARM_LDRS_SB_G1:
7629 case elfcpp::R_ARM_LDRS_SB_G2:
7630 case elfcpp::R_ARM_LDC_SB_G0:
7631 case elfcpp::R_ARM_LDC_SB_G1:
7632 case elfcpp::R_ARM_LDC_SB_G2:
7633 case elfcpp::R_ARM_MOVW_BREL_NC:
7634 case elfcpp::R_ARM_MOVT_BREL:
7635 case elfcpp::R_ARM_MOVW_BREL:
7636 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7637 case elfcpp::R_ARM_THM_MOVT_BREL:
7638 case elfcpp::R_ARM_THM_MOVW_BREL:
7639 // Relative addressing relocations.
7641 // Make a dynamic relocation if necessary.
7642 int flags = Symbol::NON_PIC_REF;
7643 if (gsym->needs_dynamic_reloc(flags))
7645 if (target->may_need_copy_reloc(gsym))
7647 target->copy_reloc(symtab, layout, object,
7648 data_shndx, output_section, gsym, reloc);
7650 else
7652 check_non_pic(object, r_type);
7653 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7654 rel_dyn->add_global(gsym, r_type, output_section, object,
7655 data_shndx, reloc.get_r_offset());
7659 break;
7661 case elfcpp::R_ARM_PC24:
7662 case elfcpp::R_ARM_THM_CALL:
7663 case elfcpp::R_ARM_PLT32:
7664 case elfcpp::R_ARM_CALL:
7665 case elfcpp::R_ARM_JUMP24:
7666 case elfcpp::R_ARM_THM_JUMP24:
7667 case elfcpp::R_ARM_SBREL31:
7668 case elfcpp::R_ARM_PREL31:
7669 case elfcpp::R_ARM_THM_JUMP19:
7670 case elfcpp::R_ARM_THM_JUMP6:
7671 case elfcpp::R_ARM_THM_JUMP11:
7672 case elfcpp::R_ARM_THM_JUMP8:
7673 // All the relocation above are branches except for the PREL31 ones.
7674 // A PREL31 relocation can point to a personality function in a shared
7675 // library. In that case we want to use a PLT because we want to
7676 // call the personality routine and the dyanmic linkers we care about
7677 // do not support dynamic PREL31 relocations. An REL31 relocation may
7678 // point to a function whose unwinding behaviour is being described but
7679 // we will not mistakenly generate a PLT for that because we should use
7680 // a local section symbol.
7682 // If the symbol is fully resolved, this is just a relative
7683 // local reloc. Otherwise we need a PLT entry.
7684 if (gsym->final_value_is_known())
7685 break;
7686 // If building a shared library, we can also skip the PLT entry
7687 // if the symbol is defined in the output file and is protected
7688 // or hidden.
7689 if (gsym->is_defined()
7690 && !gsym->is_from_dynobj()
7691 && !gsym->is_preemptible())
7692 break;
7693 target->make_plt_entry(symtab, layout, gsym);
7694 break;
7696 case elfcpp::R_ARM_GOT_BREL:
7697 case elfcpp::R_ARM_GOT_ABS:
7698 case elfcpp::R_ARM_GOT_PREL:
7700 // The symbol requires a GOT entry.
7701 Arm_output_data_got<big_endian>* got =
7702 target->got_section(symtab, layout);
7703 if (gsym->final_value_is_known())
7704 got->add_global(gsym, GOT_TYPE_STANDARD);
7705 else
7707 // If this symbol is not fully resolved, we need to add a
7708 // GOT entry with a dynamic relocation.
7709 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7710 if (gsym->is_from_dynobj()
7711 || gsym->is_undefined()
7712 || gsym->is_preemptible())
7713 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
7714 rel_dyn, elfcpp::R_ARM_GLOB_DAT);
7715 else
7717 if (got->add_global(gsym, GOT_TYPE_STANDARD))
7718 rel_dyn->add_global_relative(
7719 gsym, elfcpp::R_ARM_RELATIVE, got,
7720 gsym->got_offset(GOT_TYPE_STANDARD));
7724 break;
7726 case elfcpp::R_ARM_TARGET1:
7727 case elfcpp::R_ARM_TARGET2:
7728 // These should have been mapped to other types already.
7729 // Fall through.
7730 case elfcpp::R_ARM_COPY:
7731 case elfcpp::R_ARM_GLOB_DAT:
7732 case elfcpp::R_ARM_JUMP_SLOT:
7733 case elfcpp::R_ARM_RELATIVE:
7734 // These are relocations which should only be seen by the
7735 // dynamic linker, and should never be seen here.
7736 gold_error(_("%s: unexpected reloc %u in object file"),
7737 object->name().c_str(), r_type);
7738 break;
7740 // These are initial tls relocs, which are expected when
7741 // linking.
7742 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7743 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7744 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7745 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7746 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7748 const bool is_final = gsym->final_value_is_known();
7749 const tls::Tls_optimization optimized_type
7750 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
7751 switch (r_type)
7753 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7754 if (optimized_type == tls::TLSOPT_NONE)
7756 // Create a pair of GOT entries for the module index and
7757 // dtv-relative offset.
7758 Arm_output_data_got<big_endian>* got
7759 = target->got_section(symtab, layout);
7760 if (!parameters->doing_static_link())
7761 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
7762 target->rel_dyn_section(layout),
7763 elfcpp::R_ARM_TLS_DTPMOD32,
7764 elfcpp::R_ARM_TLS_DTPOFF32);
7765 else
7766 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
7768 else
7769 // FIXME: TLS optimization not supported yet.
7770 gold_unreachable();
7771 break;
7773 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7774 if (optimized_type == tls::TLSOPT_NONE)
7776 // Create a GOT entry for the module index.
7777 target->got_mod_index_entry(symtab, layout, object);
7779 else
7780 // FIXME: TLS optimization not supported yet.
7781 gold_unreachable();
7782 break;
7784 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7785 break;
7787 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7788 layout->set_has_static_tls();
7789 if (optimized_type == tls::TLSOPT_NONE)
7791 // Create a GOT entry for the tp-relative offset.
7792 Arm_output_data_got<big_endian>* got
7793 = target->got_section(symtab, layout);
7794 if (!parameters->doing_static_link())
7795 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
7796 target->rel_dyn_section(layout),
7797 elfcpp::R_ARM_TLS_TPOFF32);
7798 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
7800 got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
7801 unsigned int got_offset =
7802 gsym->got_offset(GOT_TYPE_TLS_OFFSET);
7803 got->add_static_reloc(got_offset,
7804 elfcpp::R_ARM_TLS_TPOFF32, gsym);
7807 else
7808 // FIXME: TLS optimization not supported yet.
7809 gold_unreachable();
7810 break;
7812 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7813 layout->set_has_static_tls();
7814 if (parameters->options().shared())
7816 // We need to create a dynamic relocation.
7817 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7818 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
7819 output_section, object,
7820 data_shndx, reloc.get_r_offset());
7822 break;
7824 default:
7825 gold_unreachable();
7828 break;
7830 default:
7831 unsupported_reloc_global(object, r_type, gsym);
7832 break;
7836 // Process relocations for gc.
7838 template<bool big_endian>
7839 void
7840 Target_arm<big_endian>::gc_process_relocs(Symbol_table* symtab,
7841 Layout* layout,
7842 Sized_relobj<32, big_endian>* object,
7843 unsigned int data_shndx,
7844 unsigned int,
7845 const unsigned char* prelocs,
7846 size_t reloc_count,
7847 Output_section* output_section,
7848 bool needs_special_offset_handling,
7849 size_t local_symbol_count,
7850 const unsigned char* plocal_symbols)
7852 typedef Target_arm<big_endian> Arm;
7853 typedef typename Target_arm<big_endian>::Scan Scan;
7855 gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan>(
7856 symtab,
7857 layout,
7858 this,
7859 object,
7860 data_shndx,
7861 prelocs,
7862 reloc_count,
7863 output_section,
7864 needs_special_offset_handling,
7865 local_symbol_count,
7866 plocal_symbols);
7869 // Scan relocations for a section.
7871 template<bool big_endian>
7872 void
7873 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
7874 Layout* layout,
7875 Sized_relobj<32, big_endian>* object,
7876 unsigned int data_shndx,
7877 unsigned int sh_type,
7878 const unsigned char* prelocs,
7879 size_t reloc_count,
7880 Output_section* output_section,
7881 bool needs_special_offset_handling,
7882 size_t local_symbol_count,
7883 const unsigned char* plocal_symbols)
7885 typedef typename Target_arm<big_endian>::Scan Scan;
7886 if (sh_type == elfcpp::SHT_RELA)
7888 gold_error(_("%s: unsupported RELA reloc section"),
7889 object->name().c_str());
7890 return;
7893 gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
7894 symtab,
7895 layout,
7896 this,
7897 object,
7898 data_shndx,
7899 prelocs,
7900 reloc_count,
7901 output_section,
7902 needs_special_offset_handling,
7903 local_symbol_count,
7904 plocal_symbols);
7907 // Finalize the sections.
7909 template<bool big_endian>
7910 void
7911 Target_arm<big_endian>::do_finalize_sections(
7912 Layout* layout,
7913 const Input_objects* input_objects,
7914 Symbol_table* symtab)
7916 // Create an empty uninitialized attribute section if we still don't have it
7917 // at this moment.
7918 if (this->attributes_section_data_ == NULL)
7919 this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
7921 // Merge processor-specific flags.
7922 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
7923 p != input_objects->relobj_end();
7924 ++p)
7926 // If this input file is a binary file, it has no processor
7927 // specific flags and attributes section.
7928 Input_file::Format format = (*p)->input_file()->format();
7929 if (format != Input_file::FORMAT_ELF)
7931 gold_assert(format == Input_file::FORMAT_BINARY);
7932 continue;
7935 Arm_relobj<big_endian>* arm_relobj =
7936 Arm_relobj<big_endian>::as_arm_relobj(*p);
7937 this->merge_processor_specific_flags(
7938 arm_relobj->name(),
7939 arm_relobj->processor_specific_flags());
7940 this->merge_object_attributes(arm_relobj->name().c_str(),
7941 arm_relobj->attributes_section_data());
7945 for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
7946 p != input_objects->dynobj_end();
7947 ++p)
7949 Arm_dynobj<big_endian>* arm_dynobj =
7950 Arm_dynobj<big_endian>::as_arm_dynobj(*p);
7951 this->merge_processor_specific_flags(
7952 arm_dynobj->name(),
7953 arm_dynobj->processor_specific_flags());
7954 this->merge_object_attributes(arm_dynobj->name().c_str(),
7955 arm_dynobj->attributes_section_data());
7958 // Check BLX use.
7959 const Object_attribute* cpu_arch_attr =
7960 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
7961 if (cpu_arch_attr->int_value() > elfcpp::TAG_CPU_ARCH_V4)
7962 this->set_may_use_blx(true);
7964 // Check if we need to use Cortex-A8 workaround.
7965 if (parameters->options().user_set_fix_cortex_a8())
7966 this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
7967 else
7969 // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
7970 // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
7971 // profile.
7972 const Object_attribute* cpu_arch_profile_attr =
7973 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
7974 this->fix_cortex_a8_ =
7975 (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
7976 && (cpu_arch_profile_attr->int_value() == 'A'
7977 || cpu_arch_profile_attr->int_value() == 0));
7980 // Check if we can use V4BX interworking.
7981 // The V4BX interworking stub contains BX instruction,
7982 // which is not specified for some profiles.
7983 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
7984 && !this->may_use_blx())
7985 gold_error(_("unable to provide V4BX reloc interworking fix up; "
7986 "the target profile does not support BX instruction"));
7988 // Fill in some more dynamic tags.
7989 const Reloc_section* rel_plt = (this->plt_ == NULL
7990 ? NULL
7991 : this->plt_->rel_plt());
7992 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
7993 this->rel_dyn_, true, false);
7995 // Emit any relocs we saved in an attempt to avoid generating COPY
7996 // relocs.
7997 if (this->copy_relocs_.any_saved_relocs())
7998 this->copy_relocs_.emit(this->rel_dyn_section(layout));
8000 // Handle the .ARM.exidx section.
8001 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8002 if (exidx_section != NULL
8003 && exidx_section->type() == elfcpp::SHT_ARM_EXIDX
8004 && !parameters->options().relocatable())
8006 // Create __exidx_start and __exdix_end symbols.
8007 symtab->define_in_output_data("__exidx_start", NULL,
8008 Symbol_table::PREDEFINED,
8009 exidx_section, 0, 0, elfcpp::STT_OBJECT,
8010 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8011 false, true);
8012 symtab->define_in_output_data("__exidx_end", NULL,
8013 Symbol_table::PREDEFINED,
8014 exidx_section, 0, 0, elfcpp::STT_OBJECT,
8015 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8016 true, true);
8018 // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8019 // the .ARM.exidx section.
8020 if (!layout->script_options()->saw_phdrs_clause())
8022 gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0, 0)
8023 == NULL);
8024 Output_segment* exidx_segment =
8025 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8026 exidx_segment->add_output_section(exidx_section, elfcpp::PF_R,
8027 false);
8031 // Create an .ARM.attributes section if there is not one already.
8032 Output_attributes_section_data* attributes_section =
8033 new Output_attributes_section_data(*this->attributes_section_data_);
8034 layout->add_output_section_data(".ARM.attributes",
8035 elfcpp::SHT_ARM_ATTRIBUTES, 0,
8036 attributes_section, false, false, false,
8037 false);
8040 // Return whether a direct absolute static relocation needs to be applied.
8041 // In cases where Scan::local() or Scan::global() has created
8042 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8043 // of the relocation is carried in the data, and we must not
8044 // apply the static relocation.
8046 template<bool big_endian>
8047 inline bool
8048 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8049 const Sized_symbol<32>* gsym,
8050 int ref_flags,
8051 bool is_32bit,
8052 Output_section* output_section)
8054 // If the output section is not allocated, then we didn't call
8055 // scan_relocs, we didn't create a dynamic reloc, and we must apply
8056 // the reloc here.
8057 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8058 return true;
8060 // For local symbols, we will have created a non-RELATIVE dynamic
8061 // relocation only if (a) the output is position independent,
8062 // (b) the relocation is absolute (not pc- or segment-relative), and
8063 // (c) the relocation is not 32 bits wide.
8064 if (gsym == NULL)
8065 return !(parameters->options().output_is_position_independent()
8066 && (ref_flags & Symbol::ABSOLUTE_REF)
8067 && !is_32bit);
8069 // For global symbols, we use the same helper routines used in the
8070 // scan pass. If we did not create a dynamic relocation, or if we
8071 // created a RELATIVE dynamic relocation, we should apply the static
8072 // relocation.
8073 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8074 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8075 && gsym->can_use_relative_reloc(ref_flags
8076 & Symbol::FUNCTION_CALL);
8077 return !has_dyn || is_rel;
8080 // Perform a relocation.
8082 template<bool big_endian>
8083 inline bool
8084 Target_arm<big_endian>::Relocate::relocate(
8085 const Relocate_info<32, big_endian>* relinfo,
8086 Target_arm* target,
8087 Output_section *output_section,
8088 size_t relnum,
8089 const elfcpp::Rel<32, big_endian>& rel,
8090 unsigned int r_type,
8091 const Sized_symbol<32>* gsym,
8092 const Symbol_value<32>* psymval,
8093 unsigned char* view,
8094 Arm_address address,
8095 section_size_type view_size)
8097 typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8099 r_type = get_real_reloc_type(r_type);
8100 const Arm_reloc_property* reloc_property =
8101 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8102 if (reloc_property == NULL)
8104 std::string reloc_name =
8105 arm_reloc_property_table->reloc_name_in_error_message(r_type);
8106 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8107 _("cannot relocate %s in object file"),
8108 reloc_name.c_str());
8109 return true;
8112 const Arm_relobj<big_endian>* object =
8113 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8115 // If the final branch target of a relocation is THUMB instruction, this
8116 // is 1. Otherwise it is 0.
8117 Arm_address thumb_bit = 0;
8118 Symbol_value<32> symval;
8119 bool is_weakly_undefined_without_plt = false;
8120 if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8122 if (gsym != NULL)
8124 // This is a global symbol. Determine if we use PLT and if the
8125 // final target is THUMB.
8126 if (gsym->use_plt_offset(reloc_is_non_pic(r_type)))
8128 // This uses a PLT, change the symbol value.
8129 symval.set_output_value(target->plt_section()->address()
8130 + gsym->plt_offset());
8131 psymval = &symval;
8133 else if (gsym->is_weak_undefined())
8135 // This is a weakly undefined symbol and we do not use PLT
8136 // for this relocation. A branch targeting this symbol will
8137 // be converted into an NOP.
8138 is_weakly_undefined_without_plt = true;
8140 else
8142 // Set thumb bit if symbol:
8143 // -Has type STT_ARM_TFUNC or
8144 // -Has type STT_FUNC, is defined and with LSB in value set.
8145 thumb_bit =
8146 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8147 || (gsym->type() == elfcpp::STT_FUNC
8148 && !gsym->is_undefined()
8149 && ((psymval->value(object, 0) & 1) != 0)))
8151 : 0);
8154 else
8156 // This is a local symbol. Determine if the final target is THUMB.
8157 // We saved this information when all the local symbols were read.
8158 elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8159 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8160 thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8163 else
8165 // This is a fake relocation synthesized for a stub. It does not have
8166 // a real symbol. We just look at the LSB of the symbol value to
8167 // determine if the target is THUMB or not.
8168 thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8171 // Strip LSB if this points to a THUMB target.
8172 if (thumb_bit != 0
8173 && reloc_property->uses_thumb_bit()
8174 && ((psymval->value(object, 0) & 1) != 0))
8176 Arm_address stripped_value =
8177 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8178 symval.set_output_value(stripped_value);
8179 psymval = &symval;
8182 // Get the GOT offset if needed.
8183 // The GOT pointer points to the end of the GOT section.
8184 // We need to subtract the size of the GOT section to get
8185 // the actual offset to use in the relocation.
8186 bool have_got_offset = false;
8187 unsigned int got_offset = 0;
8188 switch (r_type)
8190 case elfcpp::R_ARM_GOT_BREL:
8191 case elfcpp::R_ARM_GOT_PREL:
8192 if (gsym != NULL)
8194 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8195 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8196 - target->got_size());
8198 else
8200 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8201 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
8202 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8203 - target->got_size());
8205 have_got_offset = true;
8206 break;
8208 default:
8209 break;
8212 // To look up relocation stubs, we need to pass the symbol table index of
8213 // a local symbol.
8214 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8216 // Get the addressing origin of the output segment defining the
8217 // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8218 Arm_address sym_origin = 0;
8219 if (reloc_property->uses_symbol_base())
8221 if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8222 // R_ARM_BASE_ABS with the NULL symbol will give the
8223 // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8224 // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8225 sym_origin = target->got_plt_section()->address();
8226 else if (gsym == NULL)
8227 sym_origin = 0;
8228 else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8229 sym_origin = gsym->output_segment()->vaddr();
8230 else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
8231 sym_origin = gsym->output_data()->address();
8233 // TODO: Assumes the segment base to be zero for the global symbols
8234 // till the proper support for the segment-base-relative addressing
8235 // will be implemented. This is consistent with GNU ld.
8238 // For relative addressing relocation, find out the relative address base.
8239 Arm_address relative_address_base = 0;
8240 switch(reloc_property->relative_address_base())
8242 case Arm_reloc_property::RAB_NONE:
8243 // Relocations with relative address bases RAB_TLS and RAB_tp are
8244 // handled by relocate_tls. So we do not need to do anything here.
8245 case Arm_reloc_property::RAB_TLS:
8246 case Arm_reloc_property::RAB_tp:
8247 break;
8248 case Arm_reloc_property::RAB_B_S:
8249 relative_address_base = sym_origin;
8250 break;
8251 case Arm_reloc_property::RAB_GOT_ORG:
8252 relative_address_base = target->got_plt_section()->address();
8253 break;
8254 case Arm_reloc_property::RAB_P:
8255 relative_address_base = address;
8256 break;
8257 case Arm_reloc_property::RAB_Pa:
8258 relative_address_base = address & 0xfffffffcU;
8259 break;
8260 default:
8261 gold_unreachable();
8264 typename Arm_relocate_functions::Status reloc_status =
8265 Arm_relocate_functions::STATUS_OKAY;
8266 bool check_overflow = reloc_property->checks_overflow();
8267 switch (r_type)
8269 case elfcpp::R_ARM_NONE:
8270 break;
8272 case elfcpp::R_ARM_ABS8:
8273 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8274 output_section))
8275 reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
8276 break;
8278 case elfcpp::R_ARM_ABS12:
8279 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8280 output_section))
8281 reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
8282 break;
8284 case elfcpp::R_ARM_ABS16:
8285 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8286 output_section))
8287 reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
8288 break;
8290 case elfcpp::R_ARM_ABS32:
8291 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
8292 output_section))
8293 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8294 thumb_bit);
8295 break;
8297 case elfcpp::R_ARM_ABS32_NOI:
8298 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
8299 output_section))
8300 // No thumb bit for this relocation: (S + A)
8301 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8303 break;
8305 case elfcpp::R_ARM_MOVW_ABS_NC:
8306 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8307 output_section))
8308 reloc_status = Arm_relocate_functions::movw(view, object, psymval,
8309 0, thumb_bit,
8310 check_overflow);
8311 break;
8313 case elfcpp::R_ARM_MOVT_ABS:
8314 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8315 output_section))
8316 reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
8317 break;
8319 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8320 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8321 output_section))
8322 reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
8323 0, thumb_bit, false);
8324 break;
8326 case elfcpp::R_ARM_THM_MOVT_ABS:
8327 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8328 output_section))
8329 reloc_status = Arm_relocate_functions::thm_movt(view, object,
8330 psymval, 0);
8331 break;
8333 case elfcpp::R_ARM_MOVW_PREL_NC:
8334 case elfcpp::R_ARM_MOVW_BREL_NC:
8335 case elfcpp::R_ARM_MOVW_BREL:
8336 reloc_status =
8337 Arm_relocate_functions::movw(view, object, psymval,
8338 relative_address_base, thumb_bit,
8339 check_overflow);
8340 break;
8342 case elfcpp::R_ARM_MOVT_PREL:
8343 case elfcpp::R_ARM_MOVT_BREL:
8344 reloc_status =
8345 Arm_relocate_functions::movt(view, object, psymval,
8346 relative_address_base);
8347 break;
8349 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8350 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8351 case elfcpp::R_ARM_THM_MOVW_BREL:
8352 reloc_status =
8353 Arm_relocate_functions::thm_movw(view, object, psymval,
8354 relative_address_base,
8355 thumb_bit, check_overflow);
8356 break;
8358 case elfcpp::R_ARM_THM_MOVT_PREL:
8359 case elfcpp::R_ARM_THM_MOVT_BREL:
8360 reloc_status =
8361 Arm_relocate_functions::thm_movt(view, object, psymval,
8362 relative_address_base);
8363 break;
8365 case elfcpp::R_ARM_REL32:
8366 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
8367 address, thumb_bit);
8368 break;
8370 case elfcpp::R_ARM_THM_ABS5:
8371 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8372 output_section))
8373 reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
8374 break;
8376 // Thumb long branches.
8377 case elfcpp::R_ARM_THM_CALL:
8378 case elfcpp::R_ARM_THM_XPC22:
8379 case elfcpp::R_ARM_THM_JUMP24:
8380 reloc_status =
8381 Arm_relocate_functions::thumb_branch_common(
8382 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
8383 thumb_bit, is_weakly_undefined_without_plt);
8384 break;
8386 case elfcpp::R_ARM_GOTOFF32:
8388 Arm_address got_origin;
8389 got_origin = target->got_plt_section()->address();
8390 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
8391 got_origin, thumb_bit);
8393 break;
8395 case elfcpp::R_ARM_BASE_PREL:
8396 gold_assert(gsym != NULL);
8397 reloc_status =
8398 Arm_relocate_functions::base_prel(view, sym_origin, address);
8399 break;
8401 case elfcpp::R_ARM_BASE_ABS:
8403 if (!should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8404 output_section))
8405 break;
8407 reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
8409 break;
8411 case elfcpp::R_ARM_GOT_BREL:
8412 gold_assert(have_got_offset);
8413 reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
8414 break;
8416 case elfcpp::R_ARM_GOT_PREL:
8417 gold_assert(have_got_offset);
8418 // Get the address origin for GOT PLT, which is allocated right
8419 // after the GOT section, to calculate an absolute address of
8420 // the symbol GOT entry (got_origin + got_offset).
8421 Arm_address got_origin;
8422 got_origin = target->got_plt_section()->address();
8423 reloc_status = Arm_relocate_functions::got_prel(view,
8424 got_origin + got_offset,
8425 address);
8426 break;
8428 case elfcpp::R_ARM_PLT32:
8429 case elfcpp::R_ARM_CALL:
8430 case elfcpp::R_ARM_JUMP24:
8431 case elfcpp::R_ARM_XPC25:
8432 gold_assert(gsym == NULL
8433 || gsym->has_plt_offset()
8434 || gsym->final_value_is_known()
8435 || (gsym->is_defined()
8436 && !gsym->is_from_dynobj()
8437 && !gsym->is_preemptible()));
8438 reloc_status =
8439 Arm_relocate_functions::arm_branch_common(
8440 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
8441 thumb_bit, is_weakly_undefined_without_plt);
8442 break;
8444 case elfcpp::R_ARM_THM_JUMP19:
8445 reloc_status =
8446 Arm_relocate_functions::thm_jump19(view, object, psymval, address,
8447 thumb_bit);
8448 break;
8450 case elfcpp::R_ARM_THM_JUMP6:
8451 reloc_status =
8452 Arm_relocate_functions::thm_jump6(view, object, psymval, address);
8453 break;
8455 case elfcpp::R_ARM_THM_JUMP8:
8456 reloc_status =
8457 Arm_relocate_functions::thm_jump8(view, object, psymval, address);
8458 break;
8460 case elfcpp::R_ARM_THM_JUMP11:
8461 reloc_status =
8462 Arm_relocate_functions::thm_jump11(view, object, psymval, address);
8463 break;
8465 case elfcpp::R_ARM_PREL31:
8466 reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
8467 address, thumb_bit);
8468 break;
8470 case elfcpp::R_ARM_V4BX:
8471 if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
8473 const bool is_v4bx_interworking =
8474 (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
8475 reloc_status =
8476 Arm_relocate_functions::v4bx(relinfo, view, object, address,
8477 is_v4bx_interworking);
8479 break;
8481 case elfcpp::R_ARM_THM_PC8:
8482 reloc_status =
8483 Arm_relocate_functions::thm_pc8(view, object, psymval, address);
8484 break;
8486 case elfcpp::R_ARM_THM_PC12:
8487 reloc_status =
8488 Arm_relocate_functions::thm_pc12(view, object, psymval, address);
8489 break;
8491 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8492 reloc_status =
8493 Arm_relocate_functions::thm_alu11(view, object, psymval, address,
8494 thumb_bit);
8495 break;
8497 case elfcpp::R_ARM_ALU_PC_G0_NC:
8498 case elfcpp::R_ARM_ALU_PC_G0:
8499 case elfcpp::R_ARM_ALU_PC_G1_NC:
8500 case elfcpp::R_ARM_ALU_PC_G1:
8501 case elfcpp::R_ARM_ALU_PC_G2:
8502 case elfcpp::R_ARM_ALU_SB_G0_NC:
8503 case elfcpp::R_ARM_ALU_SB_G0:
8504 case elfcpp::R_ARM_ALU_SB_G1_NC:
8505 case elfcpp::R_ARM_ALU_SB_G1:
8506 case elfcpp::R_ARM_ALU_SB_G2:
8507 reloc_status =
8508 Arm_relocate_functions::arm_grp_alu(view, object, psymval,
8509 reloc_property->group_index(),
8510 relative_address_base,
8511 thumb_bit, check_overflow);
8512 break;
8514 case elfcpp::R_ARM_LDR_PC_G0:
8515 case elfcpp::R_ARM_LDR_PC_G1:
8516 case elfcpp::R_ARM_LDR_PC_G2:
8517 case elfcpp::R_ARM_LDR_SB_G0:
8518 case elfcpp::R_ARM_LDR_SB_G1:
8519 case elfcpp::R_ARM_LDR_SB_G2:
8520 reloc_status =
8521 Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
8522 reloc_property->group_index(),
8523 relative_address_base);
8524 break;
8526 case elfcpp::R_ARM_LDRS_PC_G0:
8527 case elfcpp::R_ARM_LDRS_PC_G1:
8528 case elfcpp::R_ARM_LDRS_PC_G2:
8529 case elfcpp::R_ARM_LDRS_SB_G0:
8530 case elfcpp::R_ARM_LDRS_SB_G1:
8531 case elfcpp::R_ARM_LDRS_SB_G2:
8532 reloc_status =
8533 Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
8534 reloc_property->group_index(),
8535 relative_address_base);
8536 break;
8538 case elfcpp::R_ARM_LDC_PC_G0:
8539 case elfcpp::R_ARM_LDC_PC_G1:
8540 case elfcpp::R_ARM_LDC_PC_G2:
8541 case elfcpp::R_ARM_LDC_SB_G0:
8542 case elfcpp::R_ARM_LDC_SB_G1:
8543 case elfcpp::R_ARM_LDC_SB_G2:
8544 reloc_status =
8545 Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
8546 reloc_property->group_index(),
8547 relative_address_base);
8548 break;
8550 // These are initial tls relocs, which are expected when
8551 // linking.
8552 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8553 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8554 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8555 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8556 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8557 reloc_status =
8558 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
8559 view, address, view_size);
8560 break;
8562 default:
8563 gold_unreachable();
8566 // Report any errors.
8567 switch (reloc_status)
8569 case Arm_relocate_functions::STATUS_OKAY:
8570 break;
8571 case Arm_relocate_functions::STATUS_OVERFLOW:
8572 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8573 _("relocation overflow in relocation %u"),
8574 r_type);
8575 break;
8576 case Arm_relocate_functions::STATUS_BAD_RELOC:
8577 gold_error_at_location(
8578 relinfo,
8579 relnum,
8580 rel.get_r_offset(),
8581 _("unexpected opcode while processing relocation %u"),
8582 r_type);
8583 break;
8584 default:
8585 gold_unreachable();
8588 return true;
8591 // Perform a TLS relocation.
8593 template<bool big_endian>
8594 inline typename Arm_relocate_functions<big_endian>::Status
8595 Target_arm<big_endian>::Relocate::relocate_tls(
8596 const Relocate_info<32, big_endian>* relinfo,
8597 Target_arm<big_endian>* target,
8598 size_t relnum,
8599 const elfcpp::Rel<32, big_endian>& rel,
8600 unsigned int r_type,
8601 const Sized_symbol<32>* gsym,
8602 const Symbol_value<32>* psymval,
8603 unsigned char* view,
8604 elfcpp::Elf_types<32>::Elf_Addr address,
8605 section_size_type /*view_size*/ )
8607 typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
8608 typedef Relocate_functions<32, big_endian> RelocFuncs;
8609 Output_segment* tls_segment = relinfo->layout->tls_segment();
8611 const Sized_relobj<32, big_endian>* object = relinfo->object;
8613 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
8615 const bool is_final = (gsym == NULL
8616 ? !parameters->options().shared()
8617 : gsym->final_value_is_known());
8618 const tls::Tls_optimization optimized_type
8619 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8620 switch (r_type)
8622 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8624 unsigned int got_type = GOT_TYPE_TLS_PAIR;
8625 unsigned int got_offset;
8626 if (gsym != NULL)
8628 gold_assert(gsym->has_got_offset(got_type));
8629 got_offset = gsym->got_offset(got_type) - target->got_size();
8631 else
8633 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8634 gold_assert(object->local_has_got_offset(r_sym, got_type));
8635 got_offset = (object->local_got_offset(r_sym, got_type)
8636 - target->got_size());
8638 if (optimized_type == tls::TLSOPT_NONE)
8640 Arm_address got_entry =
8641 target->got_plt_section()->address() + got_offset;
8643 // Relocate the field with the PC relative offset of the pair of
8644 // GOT entries.
8645 RelocFuncs::pcrel32(view, got_entry, address);
8646 return ArmRelocFuncs::STATUS_OKAY;
8649 break;
8651 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8652 if (optimized_type == tls::TLSOPT_NONE)
8654 // Relocate the field with the offset of the GOT entry for
8655 // the module index.
8656 unsigned int got_offset;
8657 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
8658 - target->got_size());
8659 Arm_address got_entry =
8660 target->got_plt_section()->address() + got_offset;
8662 // Relocate the field with the PC relative offset of the pair of
8663 // GOT entries.
8664 RelocFuncs::pcrel32(view, got_entry, address);
8665 return ArmRelocFuncs::STATUS_OKAY;
8667 break;
8669 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8670 RelocFuncs::rel32(view, value);
8671 return ArmRelocFuncs::STATUS_OKAY;
8673 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8674 if (optimized_type == tls::TLSOPT_NONE)
8676 // Relocate the field with the offset of the GOT entry for
8677 // the tp-relative offset of the symbol.
8678 unsigned int got_type = GOT_TYPE_TLS_OFFSET;
8679 unsigned int got_offset;
8680 if (gsym != NULL)
8682 gold_assert(gsym->has_got_offset(got_type));
8683 got_offset = gsym->got_offset(got_type);
8685 else
8687 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8688 gold_assert(object->local_has_got_offset(r_sym, got_type));
8689 got_offset = object->local_got_offset(r_sym, got_type);
8692 // All GOT offsets are relative to the end of the GOT.
8693 got_offset -= target->got_size();
8695 Arm_address got_entry =
8696 target->got_plt_section()->address() + got_offset;
8698 // Relocate the field with the PC relative offset of the GOT entry.
8699 RelocFuncs::pcrel32(view, got_entry, address);
8700 return ArmRelocFuncs::STATUS_OKAY;
8702 break;
8704 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8705 // If we're creating a shared library, a dynamic relocation will
8706 // have been created for this location, so do not apply it now.
8707 if (!parameters->options().shared())
8709 gold_assert(tls_segment != NULL);
8711 // $tp points to the TCB, which is followed by the TLS, so we
8712 // need to add TCB size to the offset.
8713 Arm_address aligned_tcb_size =
8714 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
8715 RelocFuncs::rel32(view, value + aligned_tcb_size);
8718 return ArmRelocFuncs::STATUS_OKAY;
8720 default:
8721 gold_unreachable();
8724 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8725 _("unsupported reloc %u"),
8726 r_type);
8727 return ArmRelocFuncs::STATUS_BAD_RELOC;
8730 // Relocate section data.
8732 template<bool big_endian>
8733 void
8734 Target_arm<big_endian>::relocate_section(
8735 const Relocate_info<32, big_endian>* relinfo,
8736 unsigned int sh_type,
8737 const unsigned char* prelocs,
8738 size_t reloc_count,
8739 Output_section* output_section,
8740 bool needs_special_offset_handling,
8741 unsigned char* view,
8742 Arm_address address,
8743 section_size_type view_size,
8744 const Reloc_symbol_changes* reloc_symbol_changes)
8746 typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
8747 gold_assert(sh_type == elfcpp::SHT_REL);
8749 // See if we are relocating a relaxed input section. If so, the view
8750 // covers the whole output section and we need to adjust accordingly.
8751 if (needs_special_offset_handling)
8753 const Output_relaxed_input_section* poris =
8754 output_section->find_relaxed_input_section(relinfo->object,
8755 relinfo->data_shndx);
8756 if (poris != NULL)
8758 Arm_address section_address = poris->address();
8759 section_size_type section_size = poris->data_size();
8761 gold_assert((section_address >= address)
8762 && ((section_address + section_size)
8763 <= (address + view_size)));
8765 off_t offset = section_address - address;
8766 view += offset;
8767 address += offset;
8768 view_size = section_size;
8772 gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
8773 Arm_relocate>(
8774 relinfo,
8775 this,
8776 prelocs,
8777 reloc_count,
8778 output_section,
8779 needs_special_offset_handling,
8780 view,
8781 address,
8782 view_size,
8783 reloc_symbol_changes);
8786 // Return the size of a relocation while scanning during a relocatable
8787 // link.
8789 template<bool big_endian>
8790 unsigned int
8791 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
8792 unsigned int r_type,
8793 Relobj* object)
8795 r_type = get_real_reloc_type(r_type);
8796 const Arm_reloc_property* arp =
8797 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8798 if (arp != NULL)
8799 return arp->size();
8800 else
8802 std::string reloc_name =
8803 arm_reloc_property_table->reloc_name_in_error_message(r_type);
8804 gold_error(_("%s: unexpected %s in object file"),
8805 object->name().c_str(), reloc_name.c_str());
8806 return 0;
8810 // Scan the relocs during a relocatable link.
8812 template<bool big_endian>
8813 void
8814 Target_arm<big_endian>::scan_relocatable_relocs(
8815 Symbol_table* symtab,
8816 Layout* layout,
8817 Sized_relobj<32, big_endian>* object,
8818 unsigned int data_shndx,
8819 unsigned int sh_type,
8820 const unsigned char* prelocs,
8821 size_t reloc_count,
8822 Output_section* output_section,
8823 bool needs_special_offset_handling,
8824 size_t local_symbol_count,
8825 const unsigned char* plocal_symbols,
8826 Relocatable_relocs* rr)
8828 gold_assert(sh_type == elfcpp::SHT_REL);
8830 typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
8831 Relocatable_size_for_reloc> Scan_relocatable_relocs;
8833 gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
8834 Scan_relocatable_relocs>(
8835 symtab,
8836 layout,
8837 object,
8838 data_shndx,
8839 prelocs,
8840 reloc_count,
8841 output_section,
8842 needs_special_offset_handling,
8843 local_symbol_count,
8844 plocal_symbols,
8845 rr);
8848 // Relocate a section during a relocatable link.
8850 template<bool big_endian>
8851 void
8852 Target_arm<big_endian>::relocate_for_relocatable(
8853 const Relocate_info<32, big_endian>* relinfo,
8854 unsigned int sh_type,
8855 const unsigned char* prelocs,
8856 size_t reloc_count,
8857 Output_section* output_section,
8858 off_t offset_in_output_section,
8859 const Relocatable_relocs* rr,
8860 unsigned char* view,
8861 Arm_address view_address,
8862 section_size_type view_size,
8863 unsigned char* reloc_view,
8864 section_size_type reloc_view_size)
8866 gold_assert(sh_type == elfcpp::SHT_REL);
8868 gold::relocate_for_relocatable<32, big_endian, elfcpp::SHT_REL>(
8869 relinfo,
8870 prelocs,
8871 reloc_count,
8872 output_section,
8873 offset_in_output_section,
8875 view,
8876 view_address,
8877 view_size,
8878 reloc_view,
8879 reloc_view_size);
8882 // Return the value to use for a dynamic symbol which requires special
8883 // treatment. This is how we support equality comparisons of function
8884 // pointers across shared library boundaries, as described in the
8885 // processor specific ABI supplement.
8887 template<bool big_endian>
8888 uint64_t
8889 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
8891 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
8892 return this->plt_section()->address() + gsym->plt_offset();
8895 // Map platform-specific relocs to real relocs
8897 template<bool big_endian>
8898 unsigned int
8899 Target_arm<big_endian>::get_real_reloc_type (unsigned int r_type)
8901 switch (r_type)
8903 case elfcpp::R_ARM_TARGET1:
8904 // This is either R_ARM_ABS32 or R_ARM_REL32;
8905 return elfcpp::R_ARM_ABS32;
8907 case elfcpp::R_ARM_TARGET2:
8908 // This can be any reloc type but ususally is R_ARM_GOT_PREL
8909 return elfcpp::R_ARM_GOT_PREL;
8911 default:
8912 return r_type;
8916 // Whether if two EABI versions V1 and V2 are compatible.
8918 template<bool big_endian>
8919 bool
8920 Target_arm<big_endian>::are_eabi_versions_compatible(
8921 elfcpp::Elf_Word v1,
8922 elfcpp::Elf_Word v2)
8924 // v4 and v5 are the same spec before and after it was released,
8925 // so allow mixing them.
8926 if ((v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
8927 || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
8928 return true;
8930 return v1 == v2;
8933 // Combine FLAGS from an input object called NAME and the processor-specific
8934 // flags in the ELF header of the output. Much of this is adapted from the
8935 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
8936 // in bfd/elf32-arm.c.
8938 template<bool big_endian>
8939 void
8940 Target_arm<big_endian>::merge_processor_specific_flags(
8941 const std::string& name,
8942 elfcpp::Elf_Word flags)
8944 if (this->are_processor_specific_flags_set())
8946 elfcpp::Elf_Word out_flags = this->processor_specific_flags();
8948 // Nothing to merge if flags equal to those in output.
8949 if (flags == out_flags)
8950 return;
8952 // Complain about various flag mismatches.
8953 elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
8954 elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
8955 if (!this->are_eabi_versions_compatible(version1, version2))
8956 gold_error(_("Source object %s has EABI version %d but output has "
8957 "EABI version %d."),
8958 name.c_str(),
8959 (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
8960 (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
8962 else
8964 // If the input is the default architecture and had the default
8965 // flags then do not bother setting the flags for the output
8966 // architecture, instead allow future merges to do this. If no
8967 // future merges ever set these flags then they will retain their
8968 // uninitialised values, which surprise surprise, correspond
8969 // to the default values.
8970 if (flags == 0)
8971 return;
8973 // This is the first time, just copy the flags.
8974 // We only copy the EABI version for now.
8975 this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
8979 // Adjust ELF file header.
8980 template<bool big_endian>
8981 void
8982 Target_arm<big_endian>::do_adjust_elf_header(
8983 unsigned char* view,
8984 int len) const
8986 gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
8988 elfcpp::Ehdr<32, big_endian> ehdr(view);
8989 unsigned char e_ident[elfcpp::EI_NIDENT];
8990 memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
8992 if (elfcpp::arm_eabi_version(this->processor_specific_flags())
8993 == elfcpp::EF_ARM_EABI_UNKNOWN)
8994 e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
8995 else
8996 e_ident[elfcpp::EI_OSABI] = 0;
8997 e_ident[elfcpp::EI_ABIVERSION] = 0;
8999 // FIXME: Do EF_ARM_BE8 adjustment.
9001 elfcpp::Ehdr_write<32, big_endian> oehdr(view);
9002 oehdr.put_e_ident(e_ident);
9005 // do_make_elf_object to override the same function in the base class.
9006 // We need to use a target-specific sub-class of Sized_relobj<32, big_endian>
9007 // to store ARM specific information. Hence we need to have our own
9008 // ELF object creation.
9010 template<bool big_endian>
9011 Object*
9012 Target_arm<big_endian>::do_make_elf_object(
9013 const std::string& name,
9014 Input_file* input_file,
9015 off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
9017 int et = ehdr.get_e_type();
9018 if (et == elfcpp::ET_REL)
9020 Arm_relobj<big_endian>* obj =
9021 new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
9022 obj->setup();
9023 return obj;
9025 else if (et == elfcpp::ET_DYN)
9027 Sized_dynobj<32, big_endian>* obj =
9028 new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
9029 obj->setup();
9030 return obj;
9032 else
9034 gold_error(_("%s: unsupported ELF file type %d"),
9035 name.c_str(), et);
9036 return NULL;
9040 // Read the architecture from the Tag_also_compatible_with attribute, if any.
9041 // Returns -1 if no architecture could be read.
9042 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
9044 template<bool big_endian>
9046 Target_arm<big_endian>::get_secondary_compatible_arch(
9047 const Attributes_section_data* pasd)
9049 const Object_attribute *known_attributes =
9050 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
9052 // Note: the tag and its argument below are uleb128 values, though
9053 // currently-defined values fit in one byte for each.
9054 const std::string& sv =
9055 known_attributes[elfcpp::Tag_also_compatible_with].string_value();
9056 if (sv.size() == 2
9057 && sv.data()[0] == elfcpp::Tag_CPU_arch
9058 && (sv.data()[1] & 128) != 128)
9059 return sv.data()[1];
9061 // This tag is "safely ignorable", so don't complain if it looks funny.
9062 return -1;
9065 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
9066 // The tag is removed if ARCH is -1.
9067 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
9069 template<bool big_endian>
9070 void
9071 Target_arm<big_endian>::set_secondary_compatible_arch(
9072 Attributes_section_data* pasd,
9073 int arch)
9075 Object_attribute *known_attributes =
9076 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
9078 if (arch == -1)
9080 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
9081 return;
9084 // Note: the tag and its argument below are uleb128 values, though
9085 // currently-defined values fit in one byte for each.
9086 char sv[3];
9087 sv[0] = elfcpp::Tag_CPU_arch;
9088 gold_assert(arch != 0);
9089 sv[1] = arch;
9090 sv[2] = '\0';
9092 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
9095 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
9096 // into account.
9097 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
9099 template<bool big_endian>
9101 Target_arm<big_endian>::tag_cpu_arch_combine(
9102 const char* name,
9103 int oldtag,
9104 int* secondary_compat_out,
9105 int newtag,
9106 int secondary_compat)
9108 #define T(X) elfcpp::TAG_CPU_ARCH_##X
9109 static const int v6t2[] =
9111 T(V6T2), // PRE_V4.
9112 T(V6T2), // V4.
9113 T(V6T2), // V4T.
9114 T(V6T2), // V5T.
9115 T(V6T2), // V5TE.
9116 T(V6T2), // V5TEJ.
9117 T(V6T2), // V6.
9118 T(V7), // V6KZ.
9119 T(V6T2) // V6T2.
9121 static const int v6k[] =
9123 T(V6K), // PRE_V4.
9124 T(V6K), // V4.
9125 T(V6K), // V4T.
9126 T(V6K), // V5T.
9127 T(V6K), // V5TE.
9128 T(V6K), // V5TEJ.
9129 T(V6K), // V6.
9130 T(V6KZ), // V6KZ.
9131 T(V7), // V6T2.
9132 T(V6K) // V6K.
9134 static const int v7[] =
9136 T(V7), // PRE_V4.
9137 T(V7), // V4.
9138 T(V7), // V4T.
9139 T(V7), // V5T.
9140 T(V7), // V5TE.
9141 T(V7), // V5TEJ.
9142 T(V7), // V6.
9143 T(V7), // V6KZ.
9144 T(V7), // V6T2.
9145 T(V7), // V6K.
9146 T(V7) // V7.
9148 static const int v6_m[] =
9150 -1, // PRE_V4.
9151 -1, // V4.
9152 T(V6K), // V4T.
9153 T(V6K), // V5T.
9154 T(V6K), // V5TE.
9155 T(V6K), // V5TEJ.
9156 T(V6K), // V6.
9157 T(V6KZ), // V6KZ.
9158 T(V7), // V6T2.
9159 T(V6K), // V6K.
9160 T(V7), // V7.
9161 T(V6_M) // V6_M.
9163 static const int v6s_m[] =
9165 -1, // PRE_V4.
9166 -1, // V4.
9167 T(V6K), // V4T.
9168 T(V6K), // V5T.
9169 T(V6K), // V5TE.
9170 T(V6K), // V5TEJ.
9171 T(V6K), // V6.
9172 T(V6KZ), // V6KZ.
9173 T(V7), // V6T2.
9174 T(V6K), // V6K.
9175 T(V7), // V7.
9176 T(V6S_M), // V6_M.
9177 T(V6S_M) // V6S_M.
9179 static const int v7e_m[] =
9181 -1, // PRE_V4.
9182 -1, // V4.
9183 T(V7E_M), // V4T.
9184 T(V7E_M), // V5T.
9185 T(V7E_M), // V5TE.
9186 T(V7E_M), // V5TEJ.
9187 T(V7E_M), // V6.
9188 T(V7E_M), // V6KZ.
9189 T(V7E_M), // V6T2.
9190 T(V7E_M), // V6K.
9191 T(V7E_M), // V7.
9192 T(V7E_M), // V6_M.
9193 T(V7E_M), // V6S_M.
9194 T(V7E_M) // V7E_M.
9196 static const int v4t_plus_v6_m[] =
9198 -1, // PRE_V4.
9199 -1, // V4.
9200 T(V4T), // V4T.
9201 T(V5T), // V5T.
9202 T(V5TE), // V5TE.
9203 T(V5TEJ), // V5TEJ.
9204 T(V6), // V6.
9205 T(V6KZ), // V6KZ.
9206 T(V6T2), // V6T2.
9207 T(V6K), // V6K.
9208 T(V7), // V7.
9209 T(V6_M), // V6_M.
9210 T(V6S_M), // V6S_M.
9211 T(V7E_M), // V7E_M.
9212 T(V4T_PLUS_V6_M) // V4T plus V6_M.
9214 static const int *comb[] =
9216 v6t2,
9217 v6k,
9219 v6_m,
9220 v6s_m,
9221 v7e_m,
9222 // Pseudo-architecture.
9223 v4t_plus_v6_m
9226 // Check we've not got a higher architecture than we know about.
9228 if (oldtag >= elfcpp::MAX_TAG_CPU_ARCH || newtag >= elfcpp::MAX_TAG_CPU_ARCH)
9230 gold_error(_("%s: unknown CPU architecture"), name);
9231 return -1;
9234 // Override old tag if we have a Tag_also_compatible_with on the output.
9236 if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
9237 || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
9238 oldtag = T(V4T_PLUS_V6_M);
9240 // And override the new tag if we have a Tag_also_compatible_with on the
9241 // input.
9243 if ((newtag == T(V6_M) && secondary_compat == T(V4T))
9244 || (newtag == T(V4T) && secondary_compat == T(V6_M)))
9245 newtag = T(V4T_PLUS_V6_M);
9247 // Architectures before V6KZ add features monotonically.
9248 int tagh = std::max(oldtag, newtag);
9249 if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
9250 return tagh;
9252 int tagl = std::min(oldtag, newtag);
9253 int result = comb[tagh - T(V6T2)][tagl];
9255 // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
9256 // as the canonical version.
9257 if (result == T(V4T_PLUS_V6_M))
9259 result = T(V4T);
9260 *secondary_compat_out = T(V6_M);
9262 else
9263 *secondary_compat_out = -1;
9265 if (result == -1)
9267 gold_error(_("%s: conflicting CPU architectures %d/%d"),
9268 name, oldtag, newtag);
9269 return -1;
9272 return result;
9273 #undef T
9276 // Helper to print AEABI enum tag value.
9278 template<bool big_endian>
9279 std::string
9280 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
9282 static const char *aeabi_enum_names[] =
9283 { "", "variable-size", "32-bit", "" };
9284 const size_t aeabi_enum_names_size =
9285 sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
9287 if (value < aeabi_enum_names_size)
9288 return std::string(aeabi_enum_names[value]);
9289 else
9291 char buffer[100];
9292 sprintf(buffer, "<unknown value %u>", value);
9293 return std::string(buffer);
9297 // Return the string value to store in TAG_CPU_name.
9299 template<bool big_endian>
9300 std::string
9301 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
9303 static const char *name_table[] = {
9304 // These aren't real CPU names, but we can't guess
9305 // that from the architecture version alone.
9306 "Pre v4",
9307 "ARM v4",
9308 "ARM v4T",
9309 "ARM v5T",
9310 "ARM v5TE",
9311 "ARM v5TEJ",
9312 "ARM v6",
9313 "ARM v6KZ",
9314 "ARM v6T2",
9315 "ARM v6K",
9316 "ARM v7",
9317 "ARM v6-M",
9318 "ARM v6S-M",
9319 "ARM v7E-M"
9321 const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
9323 if (value < name_table_size)
9324 return std::string(name_table[value]);
9325 else
9327 char buffer[100];
9328 sprintf(buffer, "<unknown CPU value %u>", value);
9329 return std::string(buffer);
9333 // Merge object attributes from input file called NAME with those of the
9334 // output. The input object attributes are in the object pointed by PASD.
9336 template<bool big_endian>
9337 void
9338 Target_arm<big_endian>::merge_object_attributes(
9339 const char* name,
9340 const Attributes_section_data* pasd)
9342 // Return if there is no attributes section data.
9343 if (pasd == NULL)
9344 return;
9346 // If output has no object attributes, just copy.
9347 if (this->attributes_section_data_ == NULL)
9349 this->attributes_section_data_ = new Attributes_section_data(*pasd);
9350 return;
9353 const int vendor = Object_attribute::OBJ_ATTR_PROC;
9354 const Object_attribute* in_attr = pasd->known_attributes(vendor);
9355 Object_attribute* out_attr =
9356 this->attributes_section_data_->known_attributes(vendor);
9358 // This needs to happen before Tag_ABI_FP_number_model is merged. */
9359 if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
9360 != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
9362 // Ignore mismatches if the object doesn't use floating point. */
9363 if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
9364 out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
9365 in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
9366 else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0)
9367 gold_error(_("%s uses VFP register arguments, output does not"),
9368 name);
9371 for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
9373 // Merge this attribute with existing attributes.
9374 switch (i)
9376 case elfcpp::Tag_CPU_raw_name:
9377 case elfcpp::Tag_CPU_name:
9378 // These are merged after Tag_CPU_arch.
9379 break;
9381 case elfcpp::Tag_ABI_optimization_goals:
9382 case elfcpp::Tag_ABI_FP_optimization_goals:
9383 // Use the first value seen.
9384 break;
9386 case elfcpp::Tag_CPU_arch:
9388 unsigned int saved_out_attr = out_attr->int_value();
9389 // Merge Tag_CPU_arch and Tag_also_compatible_with.
9390 int secondary_compat =
9391 this->get_secondary_compatible_arch(pasd);
9392 int secondary_compat_out =
9393 this->get_secondary_compatible_arch(
9394 this->attributes_section_data_);
9395 out_attr[i].set_int_value(
9396 tag_cpu_arch_combine(name, out_attr[i].int_value(),
9397 &secondary_compat_out,
9398 in_attr[i].int_value(),
9399 secondary_compat));
9400 this->set_secondary_compatible_arch(this->attributes_section_data_,
9401 secondary_compat_out);
9403 // Merge Tag_CPU_name and Tag_CPU_raw_name.
9404 if (out_attr[i].int_value() == saved_out_attr)
9405 ; // Leave the names alone.
9406 else if (out_attr[i].int_value() == in_attr[i].int_value())
9408 // The output architecture has been changed to match the
9409 // input architecture. Use the input names.
9410 out_attr[elfcpp::Tag_CPU_name].set_string_value(
9411 in_attr[elfcpp::Tag_CPU_name].string_value());
9412 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
9413 in_attr[elfcpp::Tag_CPU_raw_name].string_value());
9415 else
9417 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
9418 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
9421 // If we still don't have a value for Tag_CPU_name,
9422 // make one up now. Tag_CPU_raw_name remains blank.
9423 if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
9425 const std::string cpu_name =
9426 this->tag_cpu_name_value(out_attr[i].int_value());
9427 // FIXME: If we see an unknown CPU, this will be set
9428 // to "<unknown CPU n>", where n is the attribute value.
9429 // This is different from BFD, which leaves the name alone.
9430 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
9433 break;
9435 case elfcpp::Tag_ARM_ISA_use:
9436 case elfcpp::Tag_THUMB_ISA_use:
9437 case elfcpp::Tag_WMMX_arch:
9438 case elfcpp::Tag_Advanced_SIMD_arch:
9439 // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
9440 case elfcpp::Tag_ABI_FP_rounding:
9441 case elfcpp::Tag_ABI_FP_exceptions:
9442 case elfcpp::Tag_ABI_FP_user_exceptions:
9443 case elfcpp::Tag_ABI_FP_number_model:
9444 case elfcpp::Tag_VFP_HP_extension:
9445 case elfcpp::Tag_CPU_unaligned_access:
9446 case elfcpp::Tag_T2EE_use:
9447 case elfcpp::Tag_Virtualization_use:
9448 case elfcpp::Tag_MPextension_use:
9449 // Use the largest value specified.
9450 if (in_attr[i].int_value() > out_attr[i].int_value())
9451 out_attr[i].set_int_value(in_attr[i].int_value());
9452 break;
9454 case elfcpp::Tag_ABI_align8_preserved:
9455 case elfcpp::Tag_ABI_PCS_RO_data:
9456 // Use the smallest value specified.
9457 if (in_attr[i].int_value() < out_attr[i].int_value())
9458 out_attr[i].set_int_value(in_attr[i].int_value());
9459 break;
9461 case elfcpp::Tag_ABI_align8_needed:
9462 if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
9463 && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
9464 || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
9465 == 0)))
9467 // This error message should be enabled once all non-conformant
9468 // binaries in the toolchain have had the attributes set
9469 // properly.
9470 // gold_error(_("output 8-byte data alignment conflicts with %s"),
9471 // name);
9473 // Fall through.
9474 case elfcpp::Tag_ABI_FP_denormal:
9475 case elfcpp::Tag_ABI_PCS_GOT_use:
9477 // These tags have 0 = don't care, 1 = strong requirement,
9478 // 2 = weak requirement.
9479 static const int order_021[3] = {0, 2, 1};
9481 // Use the "greatest" from the sequence 0, 2, 1, or the largest
9482 // value if greater than 2 (for future-proofing).
9483 if ((in_attr[i].int_value() > 2
9484 && in_attr[i].int_value() > out_attr[i].int_value())
9485 || (in_attr[i].int_value() <= 2
9486 && out_attr[i].int_value() <= 2
9487 && (order_021[in_attr[i].int_value()]
9488 > order_021[out_attr[i].int_value()])))
9489 out_attr[i].set_int_value(in_attr[i].int_value());
9491 break;
9493 case elfcpp::Tag_CPU_arch_profile:
9494 if (out_attr[i].int_value() != in_attr[i].int_value())
9496 // 0 will merge with anything.
9497 // 'A' and 'S' merge to 'A'.
9498 // 'R' and 'S' merge to 'R'.
9499 // 'M' and 'A|R|S' is an error.
9500 if (out_attr[i].int_value() == 0
9501 || (out_attr[i].int_value() == 'S'
9502 && (in_attr[i].int_value() == 'A'
9503 || in_attr[i].int_value() == 'R')))
9504 out_attr[i].set_int_value(in_attr[i].int_value());
9505 else if (in_attr[i].int_value() == 0
9506 || (in_attr[i].int_value() == 'S'
9507 && (out_attr[i].int_value() == 'A'
9508 || out_attr[i].int_value() == 'R')))
9509 ; // Do nothing.
9510 else
9512 gold_error
9513 (_("conflicting architecture profiles %c/%c"),
9514 in_attr[i].int_value() ? in_attr[i].int_value() : '0',
9515 out_attr[i].int_value() ? out_attr[i].int_value() : '0');
9518 break;
9519 case elfcpp::Tag_VFP_arch:
9521 static const struct
9523 int ver;
9524 int regs;
9525 } vfp_versions[7] =
9527 {0, 0},
9528 {1, 16},
9529 {2, 16},
9530 {3, 32},
9531 {3, 16},
9532 {4, 32},
9533 {4, 16}
9536 // Values greater than 6 aren't defined, so just pick the
9537 // biggest.
9538 if (in_attr[i].int_value() > 6
9539 && in_attr[i].int_value() > out_attr[i].int_value())
9541 *out_attr = *in_attr;
9542 break;
9544 // The output uses the superset of input features
9545 // (ISA version) and registers.
9546 int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
9547 vfp_versions[out_attr[i].int_value()].ver);
9548 int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
9549 vfp_versions[out_attr[i].int_value()].regs);
9550 // This assumes all possible supersets are also a valid
9551 // options.
9552 int newval;
9553 for (newval = 6; newval > 0; newval--)
9555 if (regs == vfp_versions[newval].regs
9556 && ver == vfp_versions[newval].ver)
9557 break;
9559 out_attr[i].set_int_value(newval);
9561 break;
9562 case elfcpp::Tag_PCS_config:
9563 if (out_attr[i].int_value() == 0)
9564 out_attr[i].set_int_value(in_attr[i].int_value());
9565 else if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
9567 // It's sometimes ok to mix different configs, so this is only
9568 // a warning.
9569 gold_warning(_("%s: conflicting platform configuration"), name);
9571 break;
9572 case elfcpp::Tag_ABI_PCS_R9_use:
9573 if (in_attr[i].int_value() != out_attr[i].int_value()
9574 && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
9575 && in_attr[i].int_value() != elfcpp::AEABI_R9_unused)
9577 gold_error(_("%s: conflicting use of R9"), name);
9579 if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
9580 out_attr[i].set_int_value(in_attr[i].int_value());
9581 break;
9582 case elfcpp::Tag_ABI_PCS_RW_data:
9583 if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
9584 && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
9585 != elfcpp::AEABI_R9_SB)
9586 && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
9587 != elfcpp::AEABI_R9_unused))
9589 gold_error(_("%s: SB relative addressing conflicts with use "
9590 "of R9"),
9591 name);
9593 // Use the smallest value specified.
9594 if (in_attr[i].int_value() < out_attr[i].int_value())
9595 out_attr[i].set_int_value(in_attr[i].int_value());
9596 break;
9597 case elfcpp::Tag_ABI_PCS_wchar_t:
9598 // FIXME: Make it possible to turn off this warning.
9599 if (out_attr[i].int_value()
9600 && in_attr[i].int_value()
9601 && out_attr[i].int_value() != in_attr[i].int_value())
9603 gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
9604 "use %u-byte wchar_t; use of wchar_t values "
9605 "across objects may fail"),
9606 name, in_attr[i].int_value(),
9607 out_attr[i].int_value());
9609 else if (in_attr[i].int_value() && !out_attr[i].int_value())
9610 out_attr[i].set_int_value(in_attr[i].int_value());
9611 break;
9612 case elfcpp::Tag_ABI_enum_size:
9613 if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
9615 if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
9616 || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
9618 // The existing object is compatible with anything.
9619 // Use whatever requirements the new object has.
9620 out_attr[i].set_int_value(in_attr[i].int_value());
9622 // FIXME: Make it possible to turn off this warning.
9623 else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
9624 && out_attr[i].int_value() != in_attr[i].int_value())
9626 unsigned int in_value = in_attr[i].int_value();
9627 unsigned int out_value = out_attr[i].int_value();
9628 gold_warning(_("%s uses %s enums yet the output is to use "
9629 "%s enums; use of enum values across objects "
9630 "may fail"),
9631 name,
9632 this->aeabi_enum_name(in_value).c_str(),
9633 this->aeabi_enum_name(out_value).c_str());
9636 break;
9637 case elfcpp::Tag_ABI_VFP_args:
9638 // Aready done.
9639 break;
9640 case elfcpp::Tag_ABI_WMMX_args:
9641 if (in_attr[i].int_value() != out_attr[i].int_value())
9643 gold_error(_("%s uses iWMMXt register arguments, output does "
9644 "not"),
9645 name);
9647 break;
9648 case Object_attribute::Tag_compatibility:
9649 // Merged in target-independent code.
9650 break;
9651 case elfcpp::Tag_ABI_HardFP_use:
9652 // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
9653 if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
9654 || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
9655 out_attr[i].set_int_value(3);
9656 else if (in_attr[i].int_value() > out_attr[i].int_value())
9657 out_attr[i].set_int_value(in_attr[i].int_value());
9658 break;
9659 case elfcpp::Tag_ABI_FP_16bit_format:
9660 if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
9662 if (in_attr[i].int_value() != out_attr[i].int_value())
9663 gold_error(_("fp16 format mismatch between %s and output"),
9664 name);
9666 if (in_attr[i].int_value() != 0)
9667 out_attr[i].set_int_value(in_attr[i].int_value());
9668 break;
9670 case elfcpp::Tag_nodefaults:
9671 // This tag is set if it exists, but the value is unused (and is
9672 // typically zero). We don't actually need to do anything here -
9673 // the merge happens automatically when the type flags are merged
9674 // below.
9675 break;
9676 case elfcpp::Tag_also_compatible_with:
9677 // Already done in Tag_CPU_arch.
9678 break;
9679 case elfcpp::Tag_conformance:
9680 // Keep the attribute if it matches. Throw it away otherwise.
9681 // No attribute means no claim to conform.
9682 if (in_attr[i].string_value() != out_attr[i].string_value())
9683 out_attr[i].set_string_value("");
9684 break;
9686 default:
9688 const char* err_object = NULL;
9690 // The "known_obj_attributes" table does contain some undefined
9691 // attributes. Ensure that there are unused.
9692 if (out_attr[i].int_value() != 0
9693 || out_attr[i].string_value() != "")
9694 err_object = "output";
9695 else if (in_attr[i].int_value() != 0
9696 || in_attr[i].string_value() != "")
9697 err_object = name;
9699 if (err_object != NULL)
9701 // Attribute numbers >=64 (mod 128) can be safely ignored.
9702 if ((i & 127) < 64)
9703 gold_error(_("%s: unknown mandatory EABI object attribute "
9704 "%d"),
9705 err_object, i);
9706 else
9707 gold_warning(_("%s: unknown EABI object attribute %d"),
9708 err_object, i);
9711 // Only pass on attributes that match in both inputs.
9712 if (!in_attr[i].matches(out_attr[i]))
9714 out_attr[i].set_int_value(0);
9715 out_attr[i].set_string_value("");
9720 // If out_attr was copied from in_attr then it won't have a type yet.
9721 if (in_attr[i].type() && !out_attr[i].type())
9722 out_attr[i].set_type(in_attr[i].type());
9725 // Merge Tag_compatibility attributes and any common GNU ones.
9726 this->attributes_section_data_->merge(name, pasd);
9728 // Check for any attributes not known on ARM.
9729 typedef Vendor_object_attributes::Other_attributes Other_attributes;
9730 const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
9731 Other_attributes::const_iterator in_iter = in_other_attributes->begin();
9732 Other_attributes* out_other_attributes =
9733 this->attributes_section_data_->other_attributes(vendor);
9734 Other_attributes::iterator out_iter = out_other_attributes->begin();
9736 while (in_iter != in_other_attributes->end()
9737 || out_iter != out_other_attributes->end())
9739 const char* err_object = NULL;
9740 int err_tag = 0;
9742 // The tags for each list are in numerical order.
9743 // If the tags are equal, then merge.
9744 if (out_iter != out_other_attributes->end()
9745 && (in_iter == in_other_attributes->end()
9746 || in_iter->first > out_iter->first))
9748 // This attribute only exists in output. We can't merge, and we
9749 // don't know what the tag means, so delete it.
9750 err_object = "output";
9751 err_tag = out_iter->first;
9752 int saved_tag = out_iter->first;
9753 delete out_iter->second;
9754 out_other_attributes->erase(out_iter);
9755 out_iter = out_other_attributes->upper_bound(saved_tag);
9757 else if (in_iter != in_other_attributes->end()
9758 && (out_iter != out_other_attributes->end()
9759 || in_iter->first < out_iter->first))
9761 // This attribute only exists in input. We can't merge, and we
9762 // don't know what the tag means, so ignore it.
9763 err_object = name;
9764 err_tag = in_iter->first;
9765 ++in_iter;
9767 else // The tags are equal.
9769 // As present, all attributes in the list are unknown, and
9770 // therefore can't be merged meaningfully.
9771 err_object = "output";
9772 err_tag = out_iter->first;
9774 // Only pass on attributes that match in both inputs.
9775 if (!in_iter->second->matches(*(out_iter->second)))
9777 // No match. Delete the attribute.
9778 int saved_tag = out_iter->first;
9779 delete out_iter->second;
9780 out_other_attributes->erase(out_iter);
9781 out_iter = out_other_attributes->upper_bound(saved_tag);
9783 else
9785 // Matched. Keep the attribute and move to the next.
9786 ++out_iter;
9787 ++in_iter;
9791 if (err_object)
9793 // Attribute numbers >=64 (mod 128) can be safely ignored. */
9794 if ((err_tag & 127) < 64)
9796 gold_error(_("%s: unknown mandatory EABI object attribute %d"),
9797 err_object, err_tag);
9799 else
9801 gold_warning(_("%s: unknown EABI object attribute %d"),
9802 err_object, err_tag);
9808 // Stub-generation methods for Target_arm.
9810 // Make a new Arm_input_section object.
9812 template<bool big_endian>
9813 Arm_input_section<big_endian>*
9814 Target_arm<big_endian>::new_arm_input_section(
9815 Relobj* relobj,
9816 unsigned int shndx)
9818 Section_id sid(relobj, shndx);
9820 Arm_input_section<big_endian>* arm_input_section =
9821 new Arm_input_section<big_endian>(relobj, shndx);
9822 arm_input_section->init();
9824 // Register new Arm_input_section in map for look-up.
9825 std::pair<typename Arm_input_section_map::iterator, bool> ins =
9826 this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
9828 // Make sure that it we have not created another Arm_input_section
9829 // for this input section already.
9830 gold_assert(ins.second);
9832 return arm_input_section;
9835 // Find the Arm_input_section object corresponding to the SHNDX-th input
9836 // section of RELOBJ.
9838 template<bool big_endian>
9839 Arm_input_section<big_endian>*
9840 Target_arm<big_endian>::find_arm_input_section(
9841 Relobj* relobj,
9842 unsigned int shndx) const
9844 Section_id sid(relobj, shndx);
9845 typename Arm_input_section_map::const_iterator p =
9846 this->arm_input_section_map_.find(sid);
9847 return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
9850 // Make a new stub table.
9852 template<bool big_endian>
9853 Stub_table<big_endian>*
9854 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
9856 Stub_table<big_endian>* stub_table =
9857 new Stub_table<big_endian>(owner);
9858 this->stub_tables_.push_back(stub_table);
9860 stub_table->set_address(owner->address() + owner->data_size());
9861 stub_table->set_file_offset(owner->offset() + owner->data_size());
9862 stub_table->finalize_data_size();
9864 return stub_table;
9867 // Scan a relocation for stub generation.
9869 template<bool big_endian>
9870 void
9871 Target_arm<big_endian>::scan_reloc_for_stub(
9872 const Relocate_info<32, big_endian>* relinfo,
9873 unsigned int r_type,
9874 const Sized_symbol<32>* gsym,
9875 unsigned int r_sym,
9876 const Symbol_value<32>* psymval,
9877 elfcpp::Elf_types<32>::Elf_Swxword addend,
9878 Arm_address address)
9880 typedef typename Target_arm<big_endian>::Relocate Relocate;
9882 const Arm_relobj<big_endian>* arm_relobj =
9883 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9885 bool target_is_thumb;
9886 Symbol_value<32> symval;
9887 if (gsym != NULL)
9889 // This is a global symbol. Determine if we use PLT and if the
9890 // final target is THUMB.
9891 if (gsym->use_plt_offset(Relocate::reloc_is_non_pic(r_type)))
9893 // This uses a PLT, change the symbol value.
9894 symval.set_output_value(this->plt_section()->address()
9895 + gsym->plt_offset());
9896 psymval = &symval;
9897 target_is_thumb = false;
9899 else if (gsym->is_undefined())
9900 // There is no need to generate a stub symbol is undefined.
9901 return;
9902 else
9904 target_is_thumb =
9905 ((gsym->type() == elfcpp::STT_ARM_TFUNC)
9906 || (gsym->type() == elfcpp::STT_FUNC
9907 && !gsym->is_undefined()
9908 && ((psymval->value(arm_relobj, 0) & 1) != 0)));
9911 else
9913 // This is a local symbol. Determine if the final target is THUMB.
9914 target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
9917 // Strip LSB if this points to a THUMB target.
9918 const Arm_reloc_property* reloc_property =
9919 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9920 gold_assert(reloc_property != NULL);
9921 if (target_is_thumb
9922 && reloc_property->uses_thumb_bit()
9923 && ((psymval->value(arm_relobj, 0) & 1) != 0))
9925 Arm_address stripped_value =
9926 psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
9927 symval.set_output_value(stripped_value);
9928 psymval = &symval;
9931 // Get the symbol value.
9932 Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
9934 // Owing to pipelining, the PC relative branches below actually skip
9935 // two instructions when the branch offset is 0.
9936 Arm_address destination;
9937 switch (r_type)
9939 case elfcpp::R_ARM_CALL:
9940 case elfcpp::R_ARM_JUMP24:
9941 case elfcpp::R_ARM_PLT32:
9942 // ARM branches.
9943 destination = value + addend + 8;
9944 break;
9945 case elfcpp::R_ARM_THM_CALL:
9946 case elfcpp::R_ARM_THM_XPC22:
9947 case elfcpp::R_ARM_THM_JUMP24:
9948 case elfcpp::R_ARM_THM_JUMP19:
9949 // THUMB branches.
9950 destination = value + addend + 4;
9951 break;
9952 default:
9953 gold_unreachable();
9956 Reloc_stub* stub = NULL;
9957 Stub_type stub_type =
9958 Reloc_stub::stub_type_for_reloc(r_type, address, destination,
9959 target_is_thumb);
9960 if (stub_type != arm_stub_none)
9962 // Try looking up an existing stub from a stub table.
9963 Stub_table<big_endian>* stub_table =
9964 arm_relobj->stub_table(relinfo->data_shndx);
9965 gold_assert(stub_table != NULL);
9967 // Locate stub by destination.
9968 Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
9970 // Create a stub if there is not one already
9971 stub = stub_table->find_reloc_stub(stub_key);
9972 if (stub == NULL)
9974 // create a new stub and add it to stub table.
9975 stub = this->stub_factory().make_reloc_stub(stub_type);
9976 stub_table->add_reloc_stub(stub, stub_key);
9979 // Record the destination address.
9980 stub->set_destination_address(destination
9981 | (target_is_thumb ? 1 : 0));
9984 // For Cortex-A8, we need to record a relocation at 4K page boundary.
9985 if (this->fix_cortex_a8_
9986 && (r_type == elfcpp::R_ARM_THM_JUMP24
9987 || r_type == elfcpp::R_ARM_THM_JUMP19
9988 || r_type == elfcpp::R_ARM_THM_CALL
9989 || r_type == elfcpp::R_ARM_THM_XPC22)
9990 && (address & 0xfffU) == 0xffeU)
9992 // Found a candidate. Note we haven't checked the destination is
9993 // within 4K here: if we do so (and don't create a record) we can't
9994 // tell that a branch should have been relocated when scanning later.
9995 this->cortex_a8_relocs_info_[address] =
9996 new Cortex_a8_reloc(stub, r_type,
9997 destination | (target_is_thumb ? 1 : 0));
10001 // This function scans a relocation sections for stub generation.
10002 // The template parameter Relocate must be a class type which provides
10003 // a single function, relocate(), which implements the machine
10004 // specific part of a relocation.
10006 // BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type:
10007 // SHT_REL or SHT_RELA.
10009 // PRELOCS points to the relocation data. RELOC_COUNT is the number
10010 // of relocs. OUTPUT_SECTION is the output section.
10011 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
10012 // mapped to output offsets.
10014 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
10015 // VIEW_SIZE is the size. These refer to the input section, unless
10016 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
10017 // the output section.
10019 template<bool big_endian>
10020 template<int sh_type>
10021 void inline
10022 Target_arm<big_endian>::scan_reloc_section_for_stubs(
10023 const Relocate_info<32, big_endian>* relinfo,
10024 const unsigned char* prelocs,
10025 size_t reloc_count,
10026 Output_section* output_section,
10027 bool needs_special_offset_handling,
10028 const unsigned char* view,
10029 elfcpp::Elf_types<32>::Elf_Addr view_address,
10030 section_size_type)
10032 typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
10033 const int reloc_size =
10034 Reloc_types<sh_type, 32, big_endian>::reloc_size;
10036 Arm_relobj<big_endian>* arm_object =
10037 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10038 unsigned int local_count = arm_object->local_symbol_count();
10040 Comdat_behavior comdat_behavior = CB_UNDETERMINED;
10042 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
10044 Reltype reloc(prelocs);
10046 typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
10047 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
10048 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
10050 r_type = this->get_real_reloc_type(r_type);
10052 // Only a few relocation types need stubs.
10053 if ((r_type != elfcpp::R_ARM_CALL)
10054 && (r_type != elfcpp::R_ARM_JUMP24)
10055 && (r_type != elfcpp::R_ARM_PLT32)
10056 && (r_type != elfcpp::R_ARM_THM_CALL)
10057 && (r_type != elfcpp::R_ARM_THM_XPC22)
10058 && (r_type != elfcpp::R_ARM_THM_JUMP24)
10059 && (r_type != elfcpp::R_ARM_THM_JUMP19)
10060 && (r_type != elfcpp::R_ARM_V4BX))
10061 continue;
10063 section_offset_type offset =
10064 convert_to_section_size_type(reloc.get_r_offset());
10066 if (needs_special_offset_handling)
10068 offset = output_section->output_offset(relinfo->object,
10069 relinfo->data_shndx,
10070 offset);
10071 if (offset == -1)
10072 continue;
10075 // Create a v4bx stub if --fix-v4bx-interworking is used.
10076 if (r_type == elfcpp::R_ARM_V4BX)
10078 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
10080 // Get the BX instruction.
10081 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
10082 const Valtype* wv =
10083 reinterpret_cast<const Valtype*>(view + offset);
10084 elfcpp::Elf_types<32>::Elf_Swxword insn =
10085 elfcpp::Swap<32, big_endian>::readval(wv);
10086 const uint32_t reg = (insn & 0xf);
10088 if (reg < 0xf)
10090 // Try looking up an existing stub from a stub table.
10091 Stub_table<big_endian>* stub_table =
10092 arm_object->stub_table(relinfo->data_shndx);
10093 gold_assert(stub_table != NULL);
10095 if (stub_table->find_arm_v4bx_stub(reg) == NULL)
10097 // create a new stub and add it to stub table.
10098 Arm_v4bx_stub* stub =
10099 this->stub_factory().make_arm_v4bx_stub(reg);
10100 gold_assert(stub != NULL);
10101 stub_table->add_arm_v4bx_stub(stub);
10105 continue;
10108 // Get the addend.
10109 Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
10110 elfcpp::Elf_types<32>::Elf_Swxword addend =
10111 stub_addend_reader(r_type, view + offset, reloc);
10113 const Sized_symbol<32>* sym;
10115 Symbol_value<32> symval;
10116 const Symbol_value<32> *psymval;
10117 if (r_sym < local_count)
10119 sym = NULL;
10120 psymval = arm_object->local_symbol(r_sym);
10122 // If the local symbol belongs to a section we are discarding,
10123 // and that section is a debug section, try to find the
10124 // corresponding kept section and map this symbol to its
10125 // counterpart in the kept section. The symbol must not
10126 // correspond to a section we are folding.
10127 bool is_ordinary;
10128 unsigned int shndx = psymval->input_shndx(&is_ordinary);
10129 if (is_ordinary
10130 && shndx != elfcpp::SHN_UNDEF
10131 && !arm_object->is_section_included(shndx)
10132 && !(relinfo->symtab->is_section_folded(arm_object, shndx)))
10134 if (comdat_behavior == CB_UNDETERMINED)
10136 std::string name =
10137 arm_object->section_name(relinfo->data_shndx);
10138 comdat_behavior = get_comdat_behavior(name.c_str());
10140 if (comdat_behavior == CB_PRETEND)
10142 bool found;
10143 typename elfcpp::Elf_types<32>::Elf_Addr value =
10144 arm_object->map_to_kept_section(shndx, &found);
10145 if (found)
10146 symval.set_output_value(value + psymval->input_value());
10147 else
10148 symval.set_output_value(0);
10150 else
10152 symval.set_output_value(0);
10154 symval.set_no_output_symtab_entry();
10155 psymval = &symval;
10158 else
10160 const Symbol* gsym = arm_object->global_symbol(r_sym);
10161 gold_assert(gsym != NULL);
10162 if (gsym->is_forwarder())
10163 gsym = relinfo->symtab->resolve_forwards(gsym);
10165 sym = static_cast<const Sized_symbol<32>*>(gsym);
10166 if (sym->has_symtab_index())
10167 symval.set_output_symtab_index(sym->symtab_index());
10168 else
10169 symval.set_no_output_symtab_entry();
10171 // We need to compute the would-be final value of this global
10172 // symbol.
10173 const Symbol_table* symtab = relinfo->symtab;
10174 const Sized_symbol<32>* sized_symbol =
10175 symtab->get_sized_symbol<32>(gsym);
10176 Symbol_table::Compute_final_value_status status;
10177 Arm_address value =
10178 symtab->compute_final_value<32>(sized_symbol, &status);
10180 // Skip this if the symbol has not output section.
10181 if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
10182 continue;
10184 symval.set_output_value(value);
10185 psymval = &symval;
10188 // If symbol is a section symbol, we don't know the actual type of
10189 // destination. Give up.
10190 if (psymval->is_section_symbol())
10191 continue;
10193 this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
10194 addend, view_address + offset);
10198 // Scan an input section for stub generation.
10200 template<bool big_endian>
10201 void
10202 Target_arm<big_endian>::scan_section_for_stubs(
10203 const Relocate_info<32, big_endian>* relinfo,
10204 unsigned int sh_type,
10205 const unsigned char* prelocs,
10206 size_t reloc_count,
10207 Output_section* output_section,
10208 bool needs_special_offset_handling,
10209 const unsigned char* view,
10210 Arm_address view_address,
10211 section_size_type view_size)
10213 if (sh_type == elfcpp::SHT_REL)
10214 this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
10215 relinfo,
10216 prelocs,
10217 reloc_count,
10218 output_section,
10219 needs_special_offset_handling,
10220 view,
10221 view_address,
10222 view_size);
10223 else if (sh_type == elfcpp::SHT_RELA)
10224 // We do not support RELA type relocations yet. This is provided for
10225 // completeness.
10226 this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
10227 relinfo,
10228 prelocs,
10229 reloc_count,
10230 output_section,
10231 needs_special_offset_handling,
10232 view,
10233 view_address,
10234 view_size);
10235 else
10236 gold_unreachable();
10239 // Group input sections for stub generation.
10241 // We goup input sections in an output sections so that the total size,
10242 // including any padding space due to alignment is smaller than GROUP_SIZE
10243 // unless the only input section in group is bigger than GROUP_SIZE already.
10244 // Then an ARM stub table is created to follow the last input section
10245 // in group. For each group an ARM stub table is created an is placed
10246 // after the last group. If STUB_ALWATS_AFTER_BRANCH is false, we further
10247 // extend the group after the stub table.
10249 template<bool big_endian>
10250 void
10251 Target_arm<big_endian>::group_sections(
10252 Layout* layout,
10253 section_size_type group_size,
10254 bool stubs_always_after_branch)
10256 // Group input sections and insert stub table
10257 Layout::Section_list section_list;
10258 layout->get_allocated_sections(&section_list);
10259 for (Layout::Section_list::const_iterator p = section_list.begin();
10260 p != section_list.end();
10261 ++p)
10263 Arm_output_section<big_endian>* output_section =
10264 Arm_output_section<big_endian>::as_arm_output_section(*p);
10265 output_section->group_sections(group_size, stubs_always_after_branch,
10266 this);
10270 // Relaxation hook. This is where we do stub generation.
10272 template<bool big_endian>
10273 bool
10274 Target_arm<big_endian>::do_relax(
10275 int pass,
10276 const Input_objects* input_objects,
10277 Symbol_table* symtab,
10278 Layout* layout)
10280 // No need to generate stubs if this is a relocatable link.
10281 gold_assert(!parameters->options().relocatable());
10283 // If this is the first pass, we need to group input sections into
10284 // stub groups.
10285 bool done_exidx_fixup = false;
10286 if (pass == 1)
10288 // Determine the stub group size. The group size is the absolute
10289 // value of the parameter --stub-group-size. If --stub-group-size
10290 // is passed a negative value, we restict stubs to be always after
10291 // the stubbed branches.
10292 int32_t stub_group_size_param =
10293 parameters->options().stub_group_size();
10294 bool stubs_always_after_branch = stub_group_size_param < 0;
10295 section_size_type stub_group_size = abs(stub_group_size_param);
10297 // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
10298 // page as the first half of a 32-bit branch straddling two 4K pages.
10299 // This is a crude way of enforcing that.
10300 if (this->fix_cortex_a8_)
10301 stubs_always_after_branch = true;
10303 if (stub_group_size == 1)
10305 // Default value.
10306 // Thumb branch range is +-4MB has to be used as the default
10307 // maximum size (a given section can contain both ARM and Thumb
10308 // code, so the worst case has to be taken into account).
10310 // This value is 24K less than that, which allows for 2025
10311 // 12-byte stubs. If we exceed that, then we will fail to link.
10312 // The user will have to relink with an explicit group size
10313 // option.
10314 stub_group_size = 4170000;
10317 group_sections(layout, stub_group_size, stubs_always_after_branch);
10319 // Also fix .ARM.exidx section coverage.
10320 Output_section* os = layout->find_output_section(".ARM.exidx");
10321 if (os != NULL && os->type() == elfcpp::SHT_ARM_EXIDX)
10323 Arm_output_section<big_endian>* exidx_output_section =
10324 Arm_output_section<big_endian>::as_arm_output_section(os);
10325 this->fix_exidx_coverage(layout, exidx_output_section, symtab);
10326 done_exidx_fixup = true;
10330 // The Cortex-A8 stubs are sensitive to layout of code sections. At the
10331 // beginning of each relaxation pass, just blow away all the stubs.
10332 // Alternatively, we could selectively remove only the stubs and reloc
10333 // information for code sections that have moved since the last pass.
10334 // That would require more book-keeping.
10335 typedef typename Stub_table_list::iterator Stub_table_iterator;
10336 if (this->fix_cortex_a8_)
10338 // Clear all Cortex-A8 reloc information.
10339 for (typename Cortex_a8_relocs_info::const_iterator p =
10340 this->cortex_a8_relocs_info_.begin();
10341 p != this->cortex_a8_relocs_info_.end();
10342 ++p)
10343 delete p->second;
10344 this->cortex_a8_relocs_info_.clear();
10346 // Remove all Cortex-A8 stubs.
10347 for (Stub_table_iterator sp = this->stub_tables_.begin();
10348 sp != this->stub_tables_.end();
10349 ++sp)
10350 (*sp)->remove_all_cortex_a8_stubs();
10353 // Scan relocs for relocation stubs
10354 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
10355 op != input_objects->relobj_end();
10356 ++op)
10358 Arm_relobj<big_endian>* arm_relobj =
10359 Arm_relobj<big_endian>::as_arm_relobj(*op);
10360 arm_relobj->scan_sections_for_stubs(this, symtab, layout);
10363 // Check all stub tables to see if any of them have their data sizes
10364 // or addresses alignments changed. These are the only things that
10365 // matter.
10366 bool any_stub_table_changed = false;
10367 Unordered_set<const Output_section*> sections_needing_adjustment;
10368 for (Stub_table_iterator sp = this->stub_tables_.begin();
10369 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
10370 ++sp)
10372 if ((*sp)->update_data_size_and_addralign())
10374 // Update data size of stub table owner.
10375 Arm_input_section<big_endian>* owner = (*sp)->owner();
10376 uint64_t address = owner->address();
10377 off_t offset = owner->offset();
10378 owner->reset_address_and_file_offset();
10379 owner->set_address_and_file_offset(address, offset);
10381 sections_needing_adjustment.insert(owner->output_section());
10382 any_stub_table_changed = true;
10386 // Output_section_data::output_section() returns a const pointer but we
10387 // need to update output sections, so we record all output sections needing
10388 // update above and scan the sections here to find out what sections need
10389 // to be updated.
10390 for(Layout::Section_list::const_iterator p = layout->section_list().begin();
10391 p != layout->section_list().end();
10392 ++p)
10394 if (sections_needing_adjustment.find(*p)
10395 != sections_needing_adjustment.end())
10396 (*p)->set_section_offsets_need_adjustment();
10399 // Stop relaxation if no EXIDX fix-up and no stub table change.
10400 bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
10402 // Finalize the stubs in the last relaxation pass.
10403 if (!continue_relaxation)
10405 for (Stub_table_iterator sp = this->stub_tables_.begin();
10406 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
10407 ++sp)
10408 (*sp)->finalize_stubs();
10410 // Update output local symbol counts of objects if necessary.
10411 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
10412 op != input_objects->relobj_end();
10413 ++op)
10415 Arm_relobj<big_endian>* arm_relobj =
10416 Arm_relobj<big_endian>::as_arm_relobj(*op);
10418 // Update output local symbol counts. We need to discard local
10419 // symbols defined in parts of input sections that are discarded by
10420 // relaxation.
10421 if (arm_relobj->output_local_symbol_count_needs_update())
10422 arm_relobj->update_output_local_symbol_count();
10426 return continue_relaxation;
10429 // Relocate a stub.
10431 template<bool big_endian>
10432 void
10433 Target_arm<big_endian>::relocate_stub(
10434 Stub* stub,
10435 const Relocate_info<32, big_endian>* relinfo,
10436 Output_section* output_section,
10437 unsigned char* view,
10438 Arm_address address,
10439 section_size_type view_size)
10441 Relocate relocate;
10442 const Stub_template* stub_template = stub->stub_template();
10443 for (size_t i = 0; i < stub_template->reloc_count(); i++)
10445 size_t reloc_insn_index = stub_template->reloc_insn_index(i);
10446 const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
10448 unsigned int r_type = insn->r_type();
10449 section_size_type reloc_offset = stub_template->reloc_offset(i);
10450 section_size_type reloc_size = insn->size();
10451 gold_assert(reloc_offset + reloc_size <= view_size);
10453 // This is the address of the stub destination.
10454 Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
10455 Symbol_value<32> symval;
10456 symval.set_output_value(target);
10458 // Synthesize a fake reloc just in case. We don't have a symbol so
10459 // we use 0.
10460 unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
10461 memset(reloc_buffer, 0, sizeof(reloc_buffer));
10462 elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
10463 reloc_write.put_r_offset(reloc_offset);
10464 reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
10465 elfcpp::Rel<32, big_endian> rel(reloc_buffer);
10467 relocate.relocate(relinfo, this, output_section,
10468 this->fake_relnum_for_stubs, rel, r_type,
10469 NULL, &symval, view + reloc_offset,
10470 address + reloc_offset, reloc_size);
10474 // Determine whether an object attribute tag takes an integer, a
10475 // string or both.
10477 template<bool big_endian>
10479 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
10481 if (tag == Object_attribute::Tag_compatibility)
10482 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
10483 | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
10484 else if (tag == elfcpp::Tag_nodefaults)
10485 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
10486 | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
10487 else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
10488 return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
10489 else if (tag < 32)
10490 return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
10491 else
10492 return ((tag & 1) != 0
10493 ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
10494 : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
10497 // Reorder attributes.
10499 // The ABI defines that Tag_conformance should be emitted first, and that
10500 // Tag_nodefaults should be second (if either is defined). This sets those
10501 // two positions, and bumps up the position of all the remaining tags to
10502 // compensate.
10504 template<bool big_endian>
10506 Target_arm<big_endian>::do_attributes_order(int num) const
10508 // Reorder the known object attributes in output. We want to move
10509 // Tag_conformance to position 4 and Tag_conformance to position 5
10510 // and shift eveything between 4 .. Tag_conformance - 1 to make room.
10511 if (num == 4)
10512 return elfcpp::Tag_conformance;
10513 if (num == 5)
10514 return elfcpp::Tag_nodefaults;
10515 if ((num - 2) < elfcpp::Tag_nodefaults)
10516 return num - 2;
10517 if ((num - 1) < elfcpp::Tag_conformance)
10518 return num - 1;
10519 return num;
10522 // Scan a span of THUMB code for Cortex-A8 erratum.
10524 template<bool big_endian>
10525 void
10526 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
10527 Arm_relobj<big_endian>* arm_relobj,
10528 unsigned int shndx,
10529 section_size_type span_start,
10530 section_size_type span_end,
10531 const unsigned char* view,
10532 Arm_address address)
10534 // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
10536 // The opcode is BLX.W, BL.W, B.W, Bcc.W
10537 // The branch target is in the same 4KB region as the
10538 // first half of the branch.
10539 // The instruction before the branch is a 32-bit
10540 // length non-branch instruction.
10541 section_size_type i = span_start;
10542 bool last_was_32bit = false;
10543 bool last_was_branch = false;
10544 while (i < span_end)
10546 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
10547 const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
10548 uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
10549 bool is_blx = false, is_b = false;
10550 bool is_bl = false, is_bcc = false;
10552 bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
10553 if (insn_32bit)
10555 // Load the rest of the insn (in manual-friendly order).
10556 insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
10558 // Encoding T4: B<c>.W.
10559 is_b = (insn & 0xf800d000U) == 0xf0009000U;
10560 // Encoding T1: BL<c>.W.
10561 is_bl = (insn & 0xf800d000U) == 0xf000d000U;
10562 // Encoding T2: BLX<c>.W.
10563 is_blx = (insn & 0xf800d000U) == 0xf000c000U;
10564 // Encoding T3: B<c>.W (not permitted in IT block).
10565 is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
10566 && (insn & 0x07f00000U) != 0x03800000U);
10569 bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
10571 // If this instruction is a 32-bit THUMB branch that crosses a 4K
10572 // page boundary and it follows 32-bit non-branch instruction,
10573 // we need to work around.
10574 if (is_32bit_branch
10575 && ((address + i) & 0xfffU) == 0xffeU
10576 && last_was_32bit
10577 && !last_was_branch)
10579 // Check to see if there is a relocation stub for this branch.
10580 bool force_target_arm = false;
10581 bool force_target_thumb = false;
10582 const Cortex_a8_reloc* cortex_a8_reloc = NULL;
10583 Cortex_a8_relocs_info::const_iterator p =
10584 this->cortex_a8_relocs_info_.find(address + i);
10586 if (p != this->cortex_a8_relocs_info_.end())
10588 cortex_a8_reloc = p->second;
10589 bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
10591 if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
10592 && !target_is_thumb)
10593 force_target_arm = true;
10594 else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
10595 && target_is_thumb)
10596 force_target_thumb = true;
10599 off_t offset;
10600 Stub_type stub_type = arm_stub_none;
10602 // Check if we have an offending branch instruction.
10603 uint16_t upper_insn = (insn >> 16) & 0xffffU;
10604 uint16_t lower_insn = insn & 0xffffU;
10605 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
10607 if (cortex_a8_reloc != NULL
10608 && cortex_a8_reloc->reloc_stub() != NULL)
10609 // We've already made a stub for this instruction, e.g.
10610 // it's a long branch or a Thumb->ARM stub. Assume that
10611 // stub will suffice to work around the A8 erratum (see
10612 // setting of always_after_branch above).
10614 else if (is_bcc)
10616 offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
10617 lower_insn);
10618 stub_type = arm_stub_a8_veneer_b_cond;
10620 else if (is_b || is_bl || is_blx)
10622 offset = RelocFuncs::thumb32_branch_offset(upper_insn,
10623 lower_insn);
10624 if (is_blx)
10625 offset &= ~3;
10627 stub_type = (is_blx
10628 ? arm_stub_a8_veneer_blx
10629 : (is_bl
10630 ? arm_stub_a8_veneer_bl
10631 : arm_stub_a8_veneer_b));
10634 if (stub_type != arm_stub_none)
10636 Arm_address pc_for_insn = address + i + 4;
10638 // The original instruction is a BL, but the target is
10639 // an ARM instruction. If we were not making a stub,
10640 // the BL would have been converted to a BLX. Use the
10641 // BLX stub instead in that case.
10642 if (this->may_use_blx() && force_target_arm
10643 && stub_type == arm_stub_a8_veneer_bl)
10645 stub_type = arm_stub_a8_veneer_blx;
10646 is_blx = true;
10647 is_bl = false;
10649 // Conversely, if the original instruction was
10650 // BLX but the target is Thumb mode, use the BL stub.
10651 else if (force_target_thumb
10652 && stub_type == arm_stub_a8_veneer_blx)
10654 stub_type = arm_stub_a8_veneer_bl;
10655 is_blx = false;
10656 is_bl = true;
10659 if (is_blx)
10660 pc_for_insn &= ~3;
10662 // If we found a relocation, use the proper destination,
10663 // not the offset in the (unrelocated) instruction.
10664 // Note this is always done if we switched the stub type above.
10665 if (cortex_a8_reloc != NULL)
10666 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
10668 Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
10670 // Add a new stub if destination address in in the same page.
10671 if (((address + i) & ~0xfffU) == (target & ~0xfffU))
10673 Cortex_a8_stub* stub =
10674 this->stub_factory_.make_cortex_a8_stub(stub_type,
10675 arm_relobj, shndx,
10676 address + i,
10677 target, insn);
10678 Stub_table<big_endian>* stub_table =
10679 arm_relobj->stub_table(shndx);
10680 gold_assert(stub_table != NULL);
10681 stub_table->add_cortex_a8_stub(address + i, stub);
10686 i += insn_32bit ? 4 : 2;
10687 last_was_32bit = insn_32bit;
10688 last_was_branch = is_32bit_branch;
10692 // Apply the Cortex-A8 workaround.
10694 template<bool big_endian>
10695 void
10696 Target_arm<big_endian>::apply_cortex_a8_workaround(
10697 const Cortex_a8_stub* stub,
10698 Arm_address stub_address,
10699 unsigned char* insn_view,
10700 Arm_address insn_address)
10702 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
10703 Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
10704 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
10705 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
10706 off_t branch_offset = stub_address - (insn_address + 4);
10708 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
10709 switch (stub->stub_template()->type())
10711 case arm_stub_a8_veneer_b_cond:
10712 gold_assert(!utils::has_overflow<21>(branch_offset));
10713 upper_insn = RelocFuncs::thumb32_cond_branch_upper(upper_insn,
10714 branch_offset);
10715 lower_insn = RelocFuncs::thumb32_cond_branch_lower(lower_insn,
10716 branch_offset);
10717 break;
10719 case arm_stub_a8_veneer_b:
10720 case arm_stub_a8_veneer_bl:
10721 case arm_stub_a8_veneer_blx:
10722 if ((lower_insn & 0x5000U) == 0x4000U)
10723 // For a BLX instruction, make sure that the relocation is
10724 // rounded up to a word boundary. This follows the semantics of
10725 // the instruction which specifies that bit 1 of the target
10726 // address will come from bit 1 of the base address.
10727 branch_offset = (branch_offset + 2) & ~3;
10729 // Put BRANCH_OFFSET back into the insn.
10730 gold_assert(!utils::has_overflow<25>(branch_offset));
10731 upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
10732 lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
10733 break;
10735 default:
10736 gold_unreachable();
10739 // Put the relocated value back in the object file:
10740 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
10741 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
10744 template<bool big_endian>
10745 class Target_selector_arm : public Target_selector
10747 public:
10748 Target_selector_arm()
10749 : Target_selector(elfcpp::EM_ARM, 32, big_endian,
10750 (big_endian ? "elf32-bigarm" : "elf32-littlearm"))
10753 Target*
10754 do_instantiate_target()
10755 { return new Target_arm<big_endian>(); }
10758 // Fix .ARM.exidx section coverage.
10760 template<bool big_endian>
10761 void
10762 Target_arm<big_endian>::fix_exidx_coverage(
10763 Layout* layout,
10764 Arm_output_section<big_endian>* exidx_section,
10765 Symbol_table* symtab)
10767 // We need to look at all the input sections in output in ascending
10768 // order of of output address. We do that by building a sorted list
10769 // of output sections by addresses. Then we looks at the output sections
10770 // in order. The input sections in an output section are already sorted
10771 // by addresses within the output section.
10773 typedef std::set<Output_section*, output_section_address_less_than>
10774 Sorted_output_section_list;
10775 Sorted_output_section_list sorted_output_sections;
10776 Layout::Section_list section_list;
10777 layout->get_allocated_sections(&section_list);
10778 for (Layout::Section_list::const_iterator p = section_list.begin();
10779 p != section_list.end();
10780 ++p)
10782 // We only care about output sections that contain executable code.
10783 if (((*p)->flags() & elfcpp::SHF_EXECINSTR) != 0)
10784 sorted_output_sections.insert(*p);
10787 // Go over the output sections in ascending order of output addresses.
10788 typedef typename Arm_output_section<big_endian>::Text_section_list
10789 Text_section_list;
10790 Text_section_list sorted_text_sections;
10791 for(typename Sorted_output_section_list::iterator p =
10792 sorted_output_sections.begin();
10793 p != sorted_output_sections.end();
10794 ++p)
10796 Arm_output_section<big_endian>* arm_output_section =
10797 Arm_output_section<big_endian>::as_arm_output_section(*p);
10798 arm_output_section->append_text_sections_to_list(&sorted_text_sections);
10801 exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab);
10804 Target_selector_arm<false> target_selector_arm;
10805 Target_selector_arm<true> target_selector_armbe;
10807 } // End anonymous namespace.