* cisco-core.c (cisco_core_little_vec): Add initialization of
[binutils.git] / gold / arm.cc
blob98e82b970e7f6281cddcc5d2d65f95bda3068186
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 be 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 an invalid index, this points to a global symbol.
602 // Otherwise, it points to a relobj. We used the unsized and target
603 // independent Symbol and Relobj classes instead of Sized_symbol<32> and
604 // Arm_relobj, in order to avoid making the stub class a template
605 // as most of the stub machinery is endianness-neutral. However, it
606 // may require a bit of casting done by users of this class.
607 union
609 const Symbol* symbol;
610 const Relobj* relobj;
611 } u_;
612 // Addend associated with a reloc.
613 int32_t addend_;
616 protected:
617 // Reloc_stubs are created via a stub factory. So these are protected.
618 Reloc_stub(const Stub_template* stub_template)
619 : Stub(stub_template), destination_address_(invalid_address)
622 ~Reloc_stub()
625 friend class Stub_factory;
627 // Return the relocation target address of the i-th relocation in the
628 // stub.
629 Arm_address
630 do_reloc_target(size_t i)
632 // All reloc stub have only one relocation.
633 gold_assert(i == 0);
634 return this->destination_address_;
637 private:
638 // Address of destination.
639 Arm_address destination_address_;
642 // Cortex-A8 stub class. We need a Cortex-A8 stub to redirect any 32-bit
643 // THUMB branch that meets the following conditions:
645 // 1. The branch straddles across a page boundary. i.e. lower 12-bit of
646 // branch address is 0xffe.
647 // 2. The branch target address is in the same page as the first word of the
648 // branch.
649 // 3. The branch follows a 32-bit instruction which is not a branch.
651 // To do the fix up, we need to store the address of the branch instruction
652 // and its target at least. We also need to store the original branch
653 // instruction bits for the condition code in a conditional branch. The
654 // condition code is used in a special instruction template. We also want
655 // to identify input sections needing Cortex-A8 workaround quickly. We store
656 // extra information about object and section index of the code section
657 // containing a branch being fixed up. The information is used to mark
658 // the code section when we finalize the Cortex-A8 stubs.
661 class Cortex_a8_stub : public Stub
663 public:
664 ~Cortex_a8_stub()
667 // Return the object of the code section containing the branch being fixed
668 // up.
669 Relobj*
670 relobj() const
671 { return this->relobj_; }
673 // Return the section index of the code section containing the branch being
674 // fixed up.
675 unsigned int
676 shndx() const
677 { return this->shndx_; }
679 // Return the source address of stub. This is the address of the original
680 // branch instruction. LSB is 1 always set to indicate that it is a THUMB
681 // instruction.
682 Arm_address
683 source_address() const
684 { return this->source_address_; }
686 // Return the destination address of the stub. This is the branch taken
687 // address of the original branch instruction. LSB is 1 if it is a THUMB
688 // instruction address.
689 Arm_address
690 destination_address() const
691 { return this->destination_address_; }
693 // Return the instruction being fixed up.
694 uint32_t
695 original_insn() const
696 { return this->original_insn_; }
698 protected:
699 // Cortex_a8_stubs are created via a stub factory. So these are protected.
700 Cortex_a8_stub(const Stub_template* stub_template, Relobj* relobj,
701 unsigned int shndx, Arm_address source_address,
702 Arm_address destination_address, uint32_t original_insn)
703 : Stub(stub_template), relobj_(relobj), shndx_(shndx),
704 source_address_(source_address | 1U),
705 destination_address_(destination_address),
706 original_insn_(original_insn)
709 friend class Stub_factory;
711 // Return the relocation target address of the i-th relocation in the
712 // stub.
713 Arm_address
714 do_reloc_target(size_t i)
716 if (this->stub_template()->type() == arm_stub_a8_veneer_b_cond)
718 // The conditional branch veneer has two relocations.
719 gold_assert(i < 2);
720 return i == 0 ? this->source_address_ + 4 : this->destination_address_;
722 else
724 // All other Cortex-A8 stubs have only one relocation.
725 gold_assert(i == 0);
726 return this->destination_address_;
730 // Return an instruction for the THUMB16_SPECIAL_TYPE instruction template.
731 uint16_t
732 do_thumb16_special(size_t);
734 private:
735 // Object of the code section containing the branch being fixed up.
736 Relobj* relobj_;
737 // Section index of the code section containing the branch begin fixed up.
738 unsigned int shndx_;
739 // Source address of original branch.
740 Arm_address source_address_;
741 // Destination address of the original branch.
742 Arm_address destination_address_;
743 // Original branch instruction. This is needed for copying the condition
744 // code from a condition branch to its stub.
745 uint32_t original_insn_;
748 // ARMv4 BX Rx branch relocation stub class.
749 class Arm_v4bx_stub : public Stub
751 public:
752 ~Arm_v4bx_stub()
755 // Return the associated register.
756 uint32_t
757 reg() const
758 { return this->reg_; }
760 protected:
761 // Arm V4BX stubs are created via a stub factory. So these are protected.
762 Arm_v4bx_stub(const Stub_template* stub_template, const uint32_t reg)
763 : Stub(stub_template), reg_(reg)
766 friend class Stub_factory;
768 // Return the relocation target address of the i-th relocation in the
769 // stub.
770 Arm_address
771 do_reloc_target(size_t)
772 { gold_unreachable(); }
774 // This may be overridden in the child class.
775 virtual void
776 do_write(unsigned char* view, section_size_type view_size, bool big_endian)
778 if (big_endian)
779 this->do_fixed_endian_v4bx_write<true>(view, view_size);
780 else
781 this->do_fixed_endian_v4bx_write<false>(view, view_size);
784 private:
785 // A template to implement do_write.
786 template<bool big_endian>
787 void inline
788 do_fixed_endian_v4bx_write(unsigned char* view, section_size_type)
790 const Insn_template* insns = this->stub_template()->insns();
791 elfcpp::Swap<32, big_endian>::writeval(view,
792 (insns[0].data()
793 + (this->reg_ << 16)));
794 view += insns[0].size();
795 elfcpp::Swap<32, big_endian>::writeval(view,
796 (insns[1].data() + this->reg_));
797 view += insns[1].size();
798 elfcpp::Swap<32, big_endian>::writeval(view,
799 (insns[2].data() + this->reg_));
802 // A register index (r0-r14), which is associated with the stub.
803 uint32_t reg_;
806 // Stub factory class.
808 class Stub_factory
810 public:
811 // Return the unique instance of this class.
812 static const Stub_factory&
813 get_instance()
815 static Stub_factory singleton;
816 return singleton;
819 // Make a relocation stub.
820 Reloc_stub*
821 make_reloc_stub(Stub_type stub_type) const
823 gold_assert(stub_type >= arm_stub_reloc_first
824 && stub_type <= arm_stub_reloc_last);
825 return new Reloc_stub(this->stub_templates_[stub_type]);
828 // Make a Cortex-A8 stub.
829 Cortex_a8_stub*
830 make_cortex_a8_stub(Stub_type stub_type, Relobj* relobj, unsigned int shndx,
831 Arm_address source, Arm_address destination,
832 uint32_t original_insn) const
834 gold_assert(stub_type >= arm_stub_cortex_a8_first
835 && stub_type <= arm_stub_cortex_a8_last);
836 return new Cortex_a8_stub(this->stub_templates_[stub_type], relobj, shndx,
837 source, destination, original_insn);
840 // Make an ARM V4BX relocation stub.
841 // This method creates a stub from the arm_stub_v4_veneer_bx template only.
842 Arm_v4bx_stub*
843 make_arm_v4bx_stub(uint32_t reg) const
845 gold_assert(reg < 0xf);
846 return new Arm_v4bx_stub(this->stub_templates_[arm_stub_v4_veneer_bx],
847 reg);
850 private:
851 // Constructor and destructor are protected since we only return a single
852 // instance created in Stub_factory::get_instance().
854 Stub_factory();
856 // A Stub_factory may not be copied since it is a singleton.
857 Stub_factory(const Stub_factory&);
858 Stub_factory& operator=(Stub_factory&);
860 // Stub templates. These are initialized in the constructor.
861 const Stub_template* stub_templates_[arm_stub_type_last+1];
864 // A class to hold stubs for the ARM target.
866 template<bool big_endian>
867 class Stub_table : public Output_data
869 public:
870 Stub_table(Arm_input_section<big_endian>* owner)
871 : Output_data(), owner_(owner), reloc_stubs_(), reloc_stubs_size_(0),
872 reloc_stubs_addralign_(1), cortex_a8_stubs_(), arm_v4bx_stubs_(0xf),
873 prev_data_size_(0), prev_addralign_(1)
876 ~Stub_table()
879 // Owner of this stub table.
880 Arm_input_section<big_endian>*
881 owner() const
882 { return this->owner_; }
884 // Whether this stub table is empty.
885 bool
886 empty() const
888 return (this->reloc_stubs_.empty()
889 && this->cortex_a8_stubs_.empty()
890 && this->arm_v4bx_stubs_.empty());
893 // Return the current data size.
894 off_t
895 current_data_size() const
896 { return this->current_data_size_for_child(); }
898 // Add a STUB using KEY. The caller is responsible for avoiding addition
899 // if a STUB with the same key has already been added.
900 void
901 add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key)
903 const Stub_template* stub_template = stub->stub_template();
904 gold_assert(stub_template->type() == key.stub_type());
905 this->reloc_stubs_[key] = stub;
907 // Assign stub offset early. We can do this because we never remove
908 // reloc stubs and they are in the beginning of the stub table.
909 uint64_t align = stub_template->alignment();
910 this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_, align);
911 stub->set_offset(this->reloc_stubs_size_);
912 this->reloc_stubs_size_ += stub_template->size();
913 this->reloc_stubs_addralign_ =
914 std::max(this->reloc_stubs_addralign_, align);
917 // Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS.
918 // The caller is responsible for avoiding addition if a STUB with the same
919 // address has already been added.
920 void
921 add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub)
923 std::pair<Arm_address, Cortex_a8_stub*> value(address, stub);
924 this->cortex_a8_stubs_.insert(value);
927 // Add an ARM V4BX relocation stub. A register index will be retrieved
928 // from the stub.
929 void
930 add_arm_v4bx_stub(Arm_v4bx_stub* stub)
932 gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL);
933 this->arm_v4bx_stubs_[stub->reg()] = stub;
936 // Remove all Cortex-A8 stubs.
937 void
938 remove_all_cortex_a8_stubs();
940 // Look up a relocation stub using KEY. Return NULL if there is none.
941 Reloc_stub*
942 find_reloc_stub(const Reloc_stub::Key& key) const
944 typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
945 return (p != this->reloc_stubs_.end()) ? p->second : NULL;
948 // Look up an arm v4bx relocation stub using the register index.
949 // Return NULL if there is none.
950 Arm_v4bx_stub*
951 find_arm_v4bx_stub(const uint32_t reg) const
953 gold_assert(reg < 0xf);
954 return this->arm_v4bx_stubs_[reg];
957 // Relocate stubs in this stub table.
958 void
959 relocate_stubs(const Relocate_info<32, big_endian>*,
960 Target_arm<big_endian>*, Output_section*,
961 unsigned char*, Arm_address, section_size_type);
963 // Update data size and alignment at the end of a relaxation pass. Return
964 // true if either data size or alignment is different from that of the
965 // previous relaxation pass.
966 bool
967 update_data_size_and_addralign();
969 // Finalize stubs. Set the offsets of all stubs and mark input sections
970 // needing the Cortex-A8 workaround.
971 void
972 finalize_stubs();
974 // Apply Cortex-A8 workaround to an address range.
975 void
976 apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*,
977 unsigned char*, Arm_address,
978 section_size_type);
980 protected:
981 // Write out section contents.
982 void
983 do_write(Output_file*);
985 // Return the required alignment.
986 uint64_t
987 do_addralign() const
988 { return this->prev_addralign_; }
990 // Reset address and file offset.
991 void
992 do_reset_address_and_file_offset()
993 { this->set_current_data_size_for_child(this->prev_data_size_); }
995 // Set final data size.
996 void
997 set_final_data_size()
998 { this->set_data_size(this->current_data_size()); }
1000 private:
1001 // Relocate one stub.
1002 void
1003 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
1004 Target_arm<big_endian>*, Output_section*,
1005 unsigned char*, Arm_address, section_size_type);
1007 // Unordered map of relocation stubs.
1008 typedef
1009 Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
1010 Reloc_stub::Key::equal_to>
1011 Reloc_stub_map;
1013 // List of Cortex-A8 stubs ordered by addresses of branches being
1014 // fixed up in output.
1015 typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list;
1016 // List of Arm V4BX relocation stubs ordered by associated registers.
1017 typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list;
1019 // Owner of this stub table.
1020 Arm_input_section<big_endian>* owner_;
1021 // The relocation stubs.
1022 Reloc_stub_map reloc_stubs_;
1023 // Size of reloc stubs.
1024 off_t reloc_stubs_size_;
1025 // Maximum address alignment of reloc stubs.
1026 uint64_t reloc_stubs_addralign_;
1027 // The cortex_a8_stubs.
1028 Cortex_a8_stub_list cortex_a8_stubs_;
1029 // The Arm V4BX relocation stubs.
1030 Arm_v4bx_stub_list arm_v4bx_stubs_;
1031 // data size of this in the previous pass.
1032 off_t prev_data_size_;
1033 // address alignment of this in the previous pass.
1034 uint64_t prev_addralign_;
1037 // Arm_exidx_cantunwind class. This represents an EXIDX_CANTUNWIND entry
1038 // we add to the end of an EXIDX input section that goes into the output.
1040 class Arm_exidx_cantunwind : public Output_section_data
1042 public:
1043 Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
1044 : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
1047 // Return the object containing the section pointed by this.
1048 Relobj*
1049 relobj() const
1050 { return this->relobj_; }
1052 // Return the section index of the section pointed by this.
1053 unsigned int
1054 shndx() const
1055 { return this->shndx_; }
1057 protected:
1058 void
1059 do_write(Output_file* of)
1061 if (parameters->target().is_big_endian())
1062 this->do_fixed_endian_write<true>(of);
1063 else
1064 this->do_fixed_endian_write<false>(of);
1067 // Write to a map file.
1068 void
1069 do_print_to_mapfile(Mapfile* mapfile) const
1070 { mapfile->print_output_data(this, _("** ARM cantunwind")); }
1072 private:
1073 // Implement do_write for a given endianness.
1074 template<bool big_endian>
1075 void inline
1076 do_fixed_endian_write(Output_file*);
1078 // The object containing the section pointed by this.
1079 Relobj* relobj_;
1080 // The section index of the section pointed by this.
1081 unsigned int shndx_;
1084 // During EXIDX coverage fix-up, we compact an EXIDX section. The
1085 // Offset map is used to map input section offset within the EXIDX section
1086 // to the output offset from the start of this EXIDX section.
1088 typedef std::map<section_offset_type, section_offset_type>
1089 Arm_exidx_section_offset_map;
1091 // Arm_exidx_merged_section class. This represents an EXIDX input section
1092 // with some of its entries merged.
1094 class Arm_exidx_merged_section : public Output_relaxed_input_section
1096 public:
1097 // Constructor for Arm_exidx_merged_section.
1098 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
1099 // SECTION_OFFSET_MAP points to a section offset map describing how
1100 // parts of the input section are mapped to output. DELETED_BYTES is
1101 // the number of bytes deleted from the EXIDX input section.
1102 Arm_exidx_merged_section(
1103 const Arm_exidx_input_section& exidx_input_section,
1104 const Arm_exidx_section_offset_map& section_offset_map,
1105 uint32_t deleted_bytes);
1107 // Build output contents.
1108 void
1109 build_contents(const unsigned char*, section_size_type);
1111 // Return the original EXIDX input section.
1112 const Arm_exidx_input_section&
1113 exidx_input_section() const
1114 { return this->exidx_input_section_; }
1116 // Return the section offset map.
1117 const Arm_exidx_section_offset_map&
1118 section_offset_map() const
1119 { return this->section_offset_map_; }
1121 protected:
1122 // Write merged section into file OF.
1123 void
1124 do_write(Output_file* of);
1126 bool
1127 do_output_offset(const Relobj*, unsigned int, section_offset_type,
1128 section_offset_type*) const;
1130 private:
1131 // Original EXIDX input section.
1132 const Arm_exidx_input_section& exidx_input_section_;
1133 // Section offset map.
1134 const Arm_exidx_section_offset_map& section_offset_map_;
1135 // Merged section contents. We need to keep build the merged section
1136 // and save it here to avoid accessing the original EXIDX section when
1137 // we cannot lock the sections' object.
1138 unsigned char* section_contents_;
1141 // A class to wrap an ordinary input section containing executable code.
1143 template<bool big_endian>
1144 class Arm_input_section : public Output_relaxed_input_section
1146 public:
1147 Arm_input_section(Relobj* relobj, unsigned int shndx)
1148 : Output_relaxed_input_section(relobj, shndx, 1),
1149 original_addralign_(1), original_size_(0), stub_table_(NULL),
1150 original_contents_(NULL)
1153 ~Arm_input_section()
1154 { delete[] this->original_contents_; }
1156 // Initialize.
1157 void
1158 init();
1160 // Whether this is a stub table owner.
1161 bool
1162 is_stub_table_owner() const
1163 { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
1165 // Return the stub table.
1166 Stub_table<big_endian>*
1167 stub_table() const
1168 { return this->stub_table_; }
1170 // Set the stub_table.
1171 void
1172 set_stub_table(Stub_table<big_endian>* stub_table)
1173 { this->stub_table_ = stub_table; }
1175 // Downcast a base pointer to an Arm_input_section pointer. This is
1176 // not type-safe but we only use Arm_input_section not the base class.
1177 static Arm_input_section<big_endian>*
1178 as_arm_input_section(Output_relaxed_input_section* poris)
1179 { return static_cast<Arm_input_section<big_endian>*>(poris); }
1181 // Return the original size of the section.
1182 uint32_t
1183 original_size() const
1184 { return this->original_size_; }
1186 protected:
1187 // Write data to output file.
1188 void
1189 do_write(Output_file*);
1191 // Return required alignment of this.
1192 uint64_t
1193 do_addralign() const
1195 if (this->is_stub_table_owner())
1196 return std::max(this->stub_table_->addralign(),
1197 static_cast<uint64_t>(this->original_addralign_));
1198 else
1199 return this->original_addralign_;
1202 // Finalize data size.
1203 void
1204 set_final_data_size();
1206 // Reset address and file offset.
1207 void
1208 do_reset_address_and_file_offset();
1210 // Output offset.
1211 bool
1212 do_output_offset(const Relobj* object, unsigned int shndx,
1213 section_offset_type offset,
1214 section_offset_type* poutput) const
1216 if ((object == this->relobj())
1217 && (shndx == this->shndx())
1218 && (offset >= 0)
1219 && (offset <=
1220 convert_types<section_offset_type, uint32_t>(this->original_size_)))
1222 *poutput = offset;
1223 return true;
1225 else
1226 return false;
1229 private:
1230 // Copying is not allowed.
1231 Arm_input_section(const Arm_input_section&);
1232 Arm_input_section& operator=(const Arm_input_section&);
1234 // Address alignment of the original input section.
1235 uint32_t original_addralign_;
1236 // Section size of the original input section.
1237 uint32_t original_size_;
1238 // Stub table.
1239 Stub_table<big_endian>* stub_table_;
1240 // Original section contents. We have to make a copy here since the file
1241 // containing the original section may not be locked when we need to access
1242 // the contents.
1243 unsigned char* original_contents_;
1246 // Arm_exidx_fixup class. This is used to define a number of methods
1247 // and keep states for fixing up EXIDX coverage.
1249 class Arm_exidx_fixup
1251 public:
1252 Arm_exidx_fixup(Output_section* exidx_output_section,
1253 bool merge_exidx_entries = true)
1254 : exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE),
1255 last_inlined_entry_(0), last_input_section_(NULL),
1256 section_offset_map_(NULL), first_output_text_section_(NULL),
1257 merge_exidx_entries_(merge_exidx_entries)
1260 ~Arm_exidx_fixup()
1261 { delete this->section_offset_map_; }
1263 // Process an EXIDX section for entry merging. SECTION_CONTENTS points
1264 // to the EXIDX contents and SECTION_SIZE is the size of the contents. Return
1265 // number of bytes to be deleted in output. If parts of the input EXIDX
1266 // section are merged a heap allocated Arm_exidx_section_offset_map is store
1267 // in the located PSECTION_OFFSET_MAP. The caller owns the map and is
1268 // responsible for releasing it.
1269 template<bool big_endian>
1270 uint32_t
1271 process_exidx_section(const Arm_exidx_input_section* exidx_input_section,
1272 const unsigned char* section_contents,
1273 section_size_type section_size,
1274 Arm_exidx_section_offset_map** psection_offset_map);
1276 // Append an EXIDX_CANTUNWIND entry pointing at the end of the last
1277 // input section, if there is not one already.
1278 void
1279 add_exidx_cantunwind_as_needed();
1281 // Return the output section for the text section which is linked to the
1282 // first exidx input in output.
1283 Output_section*
1284 first_output_text_section() const
1285 { return this->first_output_text_section_; }
1287 private:
1288 // Copying is not allowed.
1289 Arm_exidx_fixup(const Arm_exidx_fixup&);
1290 Arm_exidx_fixup& operator=(const Arm_exidx_fixup&);
1292 // Type of EXIDX unwind entry.
1293 enum Unwind_type
1295 // No type.
1296 UT_NONE,
1297 // EXIDX_CANTUNWIND.
1298 UT_EXIDX_CANTUNWIND,
1299 // Inlined entry.
1300 UT_INLINED_ENTRY,
1301 // Normal entry.
1302 UT_NORMAL_ENTRY,
1305 // Process an EXIDX entry. We only care about the second word of the
1306 // entry. Return true if the entry can be deleted.
1307 bool
1308 process_exidx_entry(uint32_t second_word);
1310 // Update the current section offset map during EXIDX section fix-up.
1311 // If there is no map, create one. INPUT_OFFSET is the offset of a
1312 // reference point, DELETED_BYTES is the number of deleted by in the
1313 // section so far. If DELETE_ENTRY is true, the reference point and
1314 // all offsets after the previous reference point are discarded.
1315 void
1316 update_offset_map(section_offset_type input_offset,
1317 section_size_type deleted_bytes, bool delete_entry);
1319 // EXIDX output section.
1320 Output_section* exidx_output_section_;
1321 // Unwind type of the last EXIDX entry processed.
1322 Unwind_type last_unwind_type_;
1323 // Last seen inlined EXIDX entry.
1324 uint32_t last_inlined_entry_;
1325 // Last processed EXIDX input section.
1326 const Arm_exidx_input_section* last_input_section_;
1327 // Section offset map created in process_exidx_section.
1328 Arm_exidx_section_offset_map* section_offset_map_;
1329 // Output section for the text section which is linked to the first exidx
1330 // input in output.
1331 Output_section* first_output_text_section_;
1333 bool merge_exidx_entries_;
1336 // Arm output section class. This is defined mainly to add a number of
1337 // stub generation methods.
1339 template<bool big_endian>
1340 class Arm_output_section : public Output_section
1342 public:
1343 typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list;
1345 // We need to force SHF_LINK_ORDER in a SHT_ARM_EXIDX section.
1346 Arm_output_section(const char* name, elfcpp::Elf_Word type,
1347 elfcpp::Elf_Xword flags)
1348 : Output_section(name, type,
1349 (type == elfcpp::SHT_ARM_EXIDX
1350 ? flags | elfcpp::SHF_LINK_ORDER
1351 : flags))
1353 if (type == elfcpp::SHT_ARM_EXIDX)
1354 this->set_always_keeps_input_sections();
1357 ~Arm_output_section()
1360 // Group input sections for stub generation.
1361 void
1362 group_sections(section_size_type, bool, Target_arm<big_endian>*, const Task*);
1364 // Downcast a base pointer to an Arm_output_section pointer. This is
1365 // not type-safe but we only use Arm_output_section not the base class.
1366 static Arm_output_section<big_endian>*
1367 as_arm_output_section(Output_section* os)
1368 { return static_cast<Arm_output_section<big_endian>*>(os); }
1370 // Append all input text sections in this into LIST.
1371 void
1372 append_text_sections_to_list(Text_section_list* list);
1374 // Fix EXIDX coverage of this EXIDX output section. SORTED_TEXT_SECTION
1375 // is a list of text input sections sorted in ascending order of their
1376 // output addresses.
1377 void
1378 fix_exidx_coverage(Layout* layout,
1379 const Text_section_list& sorted_text_section,
1380 Symbol_table* symtab,
1381 bool merge_exidx_entries,
1382 const Task* task);
1384 // Link an EXIDX section into its corresponding text section.
1385 void
1386 set_exidx_section_link();
1388 private:
1389 // For convenience.
1390 typedef Output_section::Input_section Input_section;
1391 typedef Output_section::Input_section_list Input_section_list;
1393 // Create a stub group.
1394 void create_stub_group(Input_section_list::const_iterator,
1395 Input_section_list::const_iterator,
1396 Input_section_list::const_iterator,
1397 Target_arm<big_endian>*,
1398 std::vector<Output_relaxed_input_section*>*,
1399 const Task* task);
1402 // Arm_exidx_input_section class. This represents an EXIDX input section.
1404 class Arm_exidx_input_section
1406 public:
1407 static const section_offset_type invalid_offset =
1408 static_cast<section_offset_type>(-1);
1410 Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1411 unsigned int link, uint32_t size,
1412 uint32_t addralign, uint32_t text_size)
1413 : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1414 addralign_(addralign), text_size_(text_size), has_errors_(false)
1417 ~Arm_exidx_input_section()
1420 // Accessors: This is a read-only class.
1422 // Return the object containing this EXIDX input section.
1423 Relobj*
1424 relobj() const
1425 { return this->relobj_; }
1427 // Return the section index of this EXIDX input section.
1428 unsigned int
1429 shndx() const
1430 { return this->shndx_; }
1432 // Return the section index of linked text section in the same object.
1433 unsigned int
1434 link() const
1435 { return this->link_; }
1437 // Return size of the EXIDX input section.
1438 uint32_t
1439 size() const
1440 { return this->size_; }
1442 // Return address alignment of EXIDX input section.
1443 uint32_t
1444 addralign() const
1445 { return this->addralign_; }
1447 // Return size of the associated text input section.
1448 uint32_t
1449 text_size() const
1450 { return this->text_size_; }
1452 // Whether there are any errors in the EXIDX input section.
1453 bool
1454 has_errors() const
1455 { return this->has_errors_; }
1457 // Set has-errors flag.
1458 void
1459 set_has_errors()
1460 { this->has_errors_ = true; }
1462 private:
1463 // Object containing this.
1464 Relobj* relobj_;
1465 // Section index of this.
1466 unsigned int shndx_;
1467 // text section linked to this in the same object.
1468 unsigned int link_;
1469 // Size of this. For ARM 32-bit is sufficient.
1470 uint32_t size_;
1471 // Address alignment of this. For ARM 32-bit is sufficient.
1472 uint32_t addralign_;
1473 // Size of associated text section.
1474 uint32_t text_size_;
1475 // Whether this has any errors.
1476 bool has_errors_;
1479 // Arm_relobj class.
1481 template<bool big_endian>
1482 class Arm_relobj : public Sized_relobj_file<32, big_endian>
1484 public:
1485 static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1487 Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1488 const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1489 : Sized_relobj_file<32, big_endian>(name, input_file, offset, ehdr),
1490 stub_tables_(), local_symbol_is_thumb_function_(),
1491 attributes_section_data_(NULL), mapping_symbols_info_(),
1492 section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1493 output_local_symbol_count_needs_update_(false),
1494 merge_flags_and_attributes_(true)
1497 ~Arm_relobj()
1498 { delete this->attributes_section_data_; }
1500 // Return the stub table of the SHNDX-th section if there is one.
1501 Stub_table<big_endian>*
1502 stub_table(unsigned int shndx) const
1504 gold_assert(shndx < this->stub_tables_.size());
1505 return this->stub_tables_[shndx];
1508 // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1509 void
1510 set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1512 gold_assert(shndx < this->stub_tables_.size());
1513 this->stub_tables_[shndx] = stub_table;
1516 // Whether a local symbol is a THUMB function. R_SYM is the symbol table
1517 // index. This is only valid after do_count_local_symbol is called.
1518 bool
1519 local_symbol_is_thumb_function(unsigned int r_sym) const
1521 gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1522 return this->local_symbol_is_thumb_function_[r_sym];
1525 // Scan all relocation sections for stub generation.
1526 void
1527 scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1528 const Layout*);
1530 // Convert regular input section with index SHNDX to a relaxed section.
1531 void
1532 convert_input_section_to_relaxed_section(unsigned shndx)
1534 // The stubs have relocations and we need to process them after writing
1535 // out the stubs. So relocation now must follow section write.
1536 this->set_section_offset(shndx, -1ULL);
1537 this->set_relocs_must_follow_section_writes();
1540 // Downcast a base pointer to an Arm_relobj pointer. This is
1541 // not type-safe but we only use Arm_relobj not the base class.
1542 static Arm_relobj<big_endian>*
1543 as_arm_relobj(Relobj* relobj)
1544 { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1546 // Processor-specific flags in ELF file header. This is valid only after
1547 // reading symbols.
1548 elfcpp::Elf_Word
1549 processor_specific_flags() const
1550 { return this->processor_specific_flags_; }
1552 // Attribute section data This is the contents of the .ARM.attribute section
1553 // if there is one.
1554 const Attributes_section_data*
1555 attributes_section_data() const
1556 { return this->attributes_section_data_; }
1558 // Mapping symbol location.
1559 typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1561 // Functor for STL container.
1562 struct Mapping_symbol_position_less
1564 bool
1565 operator()(const Mapping_symbol_position& p1,
1566 const Mapping_symbol_position& p2) const
1568 return (p1.first < p2.first
1569 || (p1.first == p2.first && p1.second < p2.second));
1573 // We only care about the first character of a mapping symbol, so
1574 // we only store that instead of the whole symbol name.
1575 typedef std::map<Mapping_symbol_position, char,
1576 Mapping_symbol_position_less> Mapping_symbols_info;
1578 // Whether a section contains any Cortex-A8 workaround.
1579 bool
1580 section_has_cortex_a8_workaround(unsigned int shndx) const
1582 return (this->section_has_cortex_a8_workaround_ != NULL
1583 && (*this->section_has_cortex_a8_workaround_)[shndx]);
1586 // Mark a section that has Cortex-A8 workaround.
1587 void
1588 mark_section_for_cortex_a8_workaround(unsigned int shndx)
1590 if (this->section_has_cortex_a8_workaround_ == NULL)
1591 this->section_has_cortex_a8_workaround_ =
1592 new std::vector<bool>(this->shnum(), false);
1593 (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1596 // Return the EXIDX section of an text section with index SHNDX or NULL
1597 // if the text section has no associated EXIDX section.
1598 const Arm_exidx_input_section*
1599 exidx_input_section_by_link(unsigned int shndx) const
1601 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1602 return ((p != this->exidx_section_map_.end()
1603 && p->second->link() == shndx)
1604 ? p->second
1605 : NULL);
1608 // Return the EXIDX section with index SHNDX or NULL if there is none.
1609 const Arm_exidx_input_section*
1610 exidx_input_section_by_shndx(unsigned shndx) const
1612 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1613 return ((p != this->exidx_section_map_.end()
1614 && p->second->shndx() == shndx)
1615 ? p->second
1616 : NULL);
1619 // Whether output local symbol count needs updating.
1620 bool
1621 output_local_symbol_count_needs_update() const
1622 { return this->output_local_symbol_count_needs_update_; }
1624 // Set output_local_symbol_count_needs_update flag to be true.
1625 void
1626 set_output_local_symbol_count_needs_update()
1627 { this->output_local_symbol_count_needs_update_ = true; }
1629 // Update output local symbol count at the end of relaxation.
1630 void
1631 update_output_local_symbol_count();
1633 // Whether we want to merge processor-specific flags and attributes.
1634 bool
1635 merge_flags_and_attributes() const
1636 { return this->merge_flags_and_attributes_; }
1638 // Export list of EXIDX section indices.
1639 void
1640 get_exidx_shndx_list(std::vector<unsigned int>* list) const
1642 list->clear();
1643 for (Exidx_section_map::const_iterator p = this->exidx_section_map_.begin();
1644 p != this->exidx_section_map_.end();
1645 ++p)
1647 if (p->second->shndx() == p->first)
1648 list->push_back(p->first);
1650 // Sort list to make result independent of implementation of map.
1651 std::sort(list->begin(), list->end());
1654 protected:
1655 // Post constructor setup.
1656 void
1657 do_setup()
1659 // Call parent's setup method.
1660 Sized_relobj_file<32, big_endian>::do_setup();
1662 // Initialize look-up tables.
1663 Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1664 this->stub_tables_.swap(empty_stub_table_list);
1667 // Count the local symbols.
1668 void
1669 do_count_local_symbols(Stringpool_template<char>*,
1670 Stringpool_template<char>*);
1672 void
1673 do_relocate_sections(
1674 const Symbol_table* symtab, const Layout* layout,
1675 const unsigned char* pshdrs, Output_file* of,
1676 typename Sized_relobj_file<32, big_endian>::Views* pivews);
1678 // Read the symbol information.
1679 void
1680 do_read_symbols(Read_symbols_data* sd);
1682 // Process relocs for garbage collection.
1683 void
1684 do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1686 private:
1688 // Whether a section needs to be scanned for relocation stubs.
1689 bool
1690 section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1691 const Relobj::Output_sections&,
1692 const Symbol_table*, const unsigned char*);
1694 // Whether a section is a scannable text section.
1695 bool
1696 section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1697 const Output_section*, const Symbol_table*);
1699 // Whether a section needs to be scanned for the Cortex-A8 erratum.
1700 bool
1701 section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1702 unsigned int, Output_section*,
1703 const Symbol_table*);
1705 // Scan a section for the Cortex-A8 erratum.
1706 void
1707 scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1708 unsigned int, Output_section*,
1709 Target_arm<big_endian>*);
1711 // Find the linked text section of an EXIDX section by looking at the
1712 // first relocation of the EXIDX section. PSHDR points to the section
1713 // headers of a relocation section and PSYMS points to the local symbols.
1714 // PSHNDX points to a location storing the text section index if found.
1715 // Return whether we can find the linked section.
1716 bool
1717 find_linked_text_section(const unsigned char* pshdr,
1718 const unsigned char* psyms, unsigned int* pshndx);
1721 // Make a new Arm_exidx_input_section object for EXIDX section with
1722 // index SHNDX and section header SHDR. TEXT_SHNDX is the section
1723 // index of the linked text section.
1724 void
1725 make_exidx_input_section(unsigned int shndx,
1726 const elfcpp::Shdr<32, big_endian>& shdr,
1727 unsigned int text_shndx,
1728 const elfcpp::Shdr<32, big_endian>& text_shdr);
1730 // Return the output address of either a plain input section or a
1731 // relaxed input section. SHNDX is the section index.
1732 Arm_address
1733 simple_input_section_output_address(unsigned int, Output_section*);
1735 typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1736 typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1737 Exidx_section_map;
1739 // List of stub tables.
1740 Stub_table_list stub_tables_;
1741 // Bit vector to tell if a local symbol is a thumb function or not.
1742 // This is only valid after do_count_local_symbol is called.
1743 std::vector<bool> local_symbol_is_thumb_function_;
1744 // processor-specific flags in ELF file header.
1745 elfcpp::Elf_Word processor_specific_flags_;
1746 // Object attributes if there is an .ARM.attributes section or NULL.
1747 Attributes_section_data* attributes_section_data_;
1748 // Mapping symbols information.
1749 Mapping_symbols_info mapping_symbols_info_;
1750 // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1751 std::vector<bool>* section_has_cortex_a8_workaround_;
1752 // Map a text section to its associated .ARM.exidx section, if there is one.
1753 Exidx_section_map exidx_section_map_;
1754 // Whether output local symbol count needs updating.
1755 bool output_local_symbol_count_needs_update_;
1756 // Whether we merge processor flags and attributes of this object to
1757 // output.
1758 bool merge_flags_and_attributes_;
1761 // Arm_dynobj class.
1763 template<bool big_endian>
1764 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1766 public:
1767 Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1768 const elfcpp::Ehdr<32, big_endian>& ehdr)
1769 : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1770 processor_specific_flags_(0), attributes_section_data_(NULL)
1773 ~Arm_dynobj()
1774 { delete this->attributes_section_data_; }
1776 // Downcast a base pointer to an Arm_relobj pointer. This is
1777 // not type-safe but we only use Arm_relobj not the base class.
1778 static Arm_dynobj<big_endian>*
1779 as_arm_dynobj(Dynobj* dynobj)
1780 { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1782 // Processor-specific flags in ELF file header. This is valid only after
1783 // reading symbols.
1784 elfcpp::Elf_Word
1785 processor_specific_flags() const
1786 { return this->processor_specific_flags_; }
1788 // Attributes section data.
1789 const Attributes_section_data*
1790 attributes_section_data() const
1791 { return this->attributes_section_data_; }
1793 protected:
1794 // Read the symbol information.
1795 void
1796 do_read_symbols(Read_symbols_data* sd);
1798 private:
1799 // processor-specific flags in ELF file header.
1800 elfcpp::Elf_Word processor_specific_flags_;
1801 // Object attributes if there is an .ARM.attributes section or NULL.
1802 Attributes_section_data* attributes_section_data_;
1805 // Functor to read reloc addends during stub generation.
1807 template<int sh_type, bool big_endian>
1808 struct Stub_addend_reader
1810 // Return the addend for a relocation of a particular type. Depending
1811 // on whether this is a REL or RELA relocation, read the addend from a
1812 // view or from a Reloc object.
1813 elfcpp::Elf_types<32>::Elf_Swxword
1814 operator()(
1815 unsigned int /* r_type */,
1816 const unsigned char* /* view */,
1817 const typename Reloc_types<sh_type,
1818 32, big_endian>::Reloc& /* reloc */) const;
1821 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1823 template<bool big_endian>
1824 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1826 elfcpp::Elf_types<32>::Elf_Swxword
1827 operator()(
1828 unsigned int,
1829 const unsigned char*,
1830 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1833 // Specialized Stub_addend_reader for RELA type relocation sections.
1834 // We currently do not handle RELA type relocation sections but it is trivial
1835 // to implement the addend reader. This is provided for completeness and to
1836 // make it easier to add support for RELA relocation sections in the future.
1838 template<bool big_endian>
1839 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1841 elfcpp::Elf_types<32>::Elf_Swxword
1842 operator()(
1843 unsigned int,
1844 const unsigned char*,
1845 const typename Reloc_types<elfcpp::SHT_RELA, 32,
1846 big_endian>::Reloc& reloc) const
1847 { return reloc.get_r_addend(); }
1850 // Cortex_a8_reloc class. We keep record of relocation that may need
1851 // the Cortex-A8 erratum workaround.
1853 class Cortex_a8_reloc
1855 public:
1856 Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1857 Arm_address destination)
1858 : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1861 ~Cortex_a8_reloc()
1864 // Accessors: This is a read-only class.
1866 // Return the relocation stub associated with this relocation if there is
1867 // one.
1868 const Reloc_stub*
1869 reloc_stub() const
1870 { return this->reloc_stub_; }
1872 // Return the relocation type.
1873 unsigned int
1874 r_type() const
1875 { return this->r_type_; }
1877 // Return the destination address of the relocation. LSB stores the THUMB
1878 // bit.
1879 Arm_address
1880 destination() const
1881 { return this->destination_; }
1883 private:
1884 // Associated relocation stub if there is one, or NULL.
1885 const Reloc_stub* reloc_stub_;
1886 // Relocation type.
1887 unsigned int r_type_;
1888 // Destination address of this relocation. LSB is used to distinguish
1889 // ARM/THUMB mode.
1890 Arm_address destination_;
1893 // Arm_output_data_got class. We derive this from Output_data_got to add
1894 // extra methods to handle TLS relocations in a static link.
1896 template<bool big_endian>
1897 class Arm_output_data_got : public Output_data_got<32, big_endian>
1899 public:
1900 Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1901 : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1904 // Add a static entry for the GOT entry at OFFSET. GSYM is a global
1905 // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1906 // applied in a static link.
1907 void
1908 add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1909 { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1911 // Add a static reloc for the GOT entry at OFFSET. RELOBJ is an object
1912 // defining a local symbol with INDEX. R_TYPE is the code of a dynamic
1913 // relocation that needs to be applied in a static link.
1914 void
1915 add_static_reloc(unsigned int got_offset, unsigned int r_type,
1916 Sized_relobj_file<32, big_endian>* relobj,
1917 unsigned int index)
1919 this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1920 index));
1923 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
1924 // The first one is initialized to be 1, which is the module index for
1925 // the main executable and the second one 0. A reloc of the type
1926 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1927 // be applied by gold. GSYM is a global symbol.
1928 void
1929 add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1931 // Same as the above but for a local symbol in OBJECT with INDEX.
1932 void
1933 add_tls_gd32_with_static_reloc(unsigned int got_type,
1934 Sized_relobj_file<32, big_endian>* object,
1935 unsigned int index);
1937 protected:
1938 // Write out the GOT table.
1939 void
1940 do_write(Output_file*);
1942 private:
1943 // This class represent dynamic relocations that need to be applied by
1944 // gold because we are using TLS relocations in a static link.
1945 class Static_reloc
1947 public:
1948 Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1949 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1950 { this->u_.global.symbol = gsym; }
1952 Static_reloc(unsigned int got_offset, unsigned int r_type,
1953 Sized_relobj_file<32, big_endian>* relobj, unsigned int index)
1954 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1956 this->u_.local.relobj = relobj;
1957 this->u_.local.index = index;
1960 // Return the GOT offset.
1961 unsigned int
1962 got_offset() const
1963 { return this->got_offset_; }
1965 // Relocation type.
1966 unsigned int
1967 r_type() const
1968 { return this->r_type_; }
1970 // Whether the symbol is global or not.
1971 bool
1972 symbol_is_global() const
1973 { return this->symbol_is_global_; }
1975 // For a relocation against a global symbol, the global symbol.
1976 Symbol*
1977 symbol() const
1979 gold_assert(this->symbol_is_global_);
1980 return this->u_.global.symbol;
1983 // For a relocation against a local symbol, the defining object.
1984 Sized_relobj_file<32, big_endian>*
1985 relobj() const
1987 gold_assert(!this->symbol_is_global_);
1988 return this->u_.local.relobj;
1991 // For a relocation against a local symbol, the local symbol index.
1992 unsigned int
1993 index() const
1995 gold_assert(!this->symbol_is_global_);
1996 return this->u_.local.index;
1999 private:
2000 // GOT offset of the entry to which this relocation is applied.
2001 unsigned int got_offset_;
2002 // Type of relocation.
2003 unsigned int r_type_;
2004 // Whether this relocation is against a global symbol.
2005 bool symbol_is_global_;
2006 // A global or local symbol.
2007 union
2009 struct
2011 // For a global symbol, the symbol itself.
2012 Symbol* symbol;
2013 } global;
2014 struct
2016 // For a local symbol, the object defining object.
2017 Sized_relobj_file<32, big_endian>* relobj;
2018 // For a local symbol, the symbol index.
2019 unsigned int index;
2020 } local;
2021 } u_;
2024 // Symbol table of the output object.
2025 Symbol_table* symbol_table_;
2026 // Layout of the output object.
2027 Layout* layout_;
2028 // Static relocs to be applied to the GOT.
2029 std::vector<Static_reloc> static_relocs_;
2032 // The ARM target has many relocation types with odd-sizes or noncontiguous
2033 // bits. The default handling of relocatable relocation cannot process these
2034 // relocations. So we have to extend the default code.
2036 template<bool big_endian, int sh_type, typename Classify_reloc>
2037 class Arm_scan_relocatable_relocs :
2038 public Default_scan_relocatable_relocs<sh_type, Classify_reloc>
2040 public:
2041 // Return the strategy to use for a local symbol which is a section
2042 // symbol, given the relocation type.
2043 inline Relocatable_relocs::Reloc_strategy
2044 local_section_strategy(unsigned int r_type, Relobj*)
2046 if (sh_type == elfcpp::SHT_RELA)
2047 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
2048 else
2050 if (r_type == elfcpp::R_ARM_TARGET1
2051 || r_type == elfcpp::R_ARM_TARGET2)
2053 const Target_arm<big_endian>* arm_target =
2054 Target_arm<big_endian>::default_target();
2055 r_type = arm_target->get_real_reloc_type(r_type);
2058 switch(r_type)
2060 // Relocations that write nothing. These exclude R_ARM_TARGET1
2061 // and R_ARM_TARGET2.
2062 case elfcpp::R_ARM_NONE:
2063 case elfcpp::R_ARM_V4BX:
2064 case elfcpp::R_ARM_TLS_GOTDESC:
2065 case elfcpp::R_ARM_TLS_CALL:
2066 case elfcpp::R_ARM_TLS_DESCSEQ:
2067 case elfcpp::R_ARM_THM_TLS_CALL:
2068 case elfcpp::R_ARM_GOTRELAX:
2069 case elfcpp::R_ARM_GNU_VTENTRY:
2070 case elfcpp::R_ARM_GNU_VTINHERIT:
2071 case elfcpp::R_ARM_THM_TLS_DESCSEQ16:
2072 case elfcpp::R_ARM_THM_TLS_DESCSEQ32:
2073 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
2074 // These should have been converted to something else above.
2075 case elfcpp::R_ARM_TARGET1:
2076 case elfcpp::R_ARM_TARGET2:
2077 gold_unreachable();
2078 // Relocations that write full 32 bits.
2079 case elfcpp::R_ARM_ABS32:
2080 case elfcpp::R_ARM_REL32:
2081 case elfcpp::R_ARM_SBREL32:
2082 case elfcpp::R_ARM_GOTOFF32:
2083 case elfcpp::R_ARM_BASE_PREL:
2084 case elfcpp::R_ARM_GOT_BREL:
2085 case elfcpp::R_ARM_BASE_ABS:
2086 case elfcpp::R_ARM_ABS32_NOI:
2087 case elfcpp::R_ARM_REL32_NOI:
2088 case elfcpp::R_ARM_PLT32_ABS:
2089 case elfcpp::R_ARM_GOT_ABS:
2090 case elfcpp::R_ARM_GOT_PREL:
2091 case elfcpp::R_ARM_TLS_GD32:
2092 case elfcpp::R_ARM_TLS_LDM32:
2093 case elfcpp::R_ARM_TLS_LDO32:
2094 case elfcpp::R_ARM_TLS_IE32:
2095 case elfcpp::R_ARM_TLS_LE32:
2096 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4;
2097 default:
2098 // For all other static relocations, return RELOC_SPECIAL.
2099 return Relocatable_relocs::RELOC_SPECIAL;
2105 // Utilities for manipulating integers of up to 32-bits
2107 namespace utils
2109 // Sign extend an n-bit unsigned integer stored in an uint32_t into
2110 // an int32_t. NO_BITS must be between 1 to 32.
2111 template<int no_bits>
2112 static inline int32_t
2113 sign_extend(uint32_t bits)
2115 gold_assert(no_bits >= 0 && no_bits <= 32);
2116 if (no_bits == 32)
2117 return static_cast<int32_t>(bits);
2118 uint32_t mask = (~((uint32_t) 0)) >> (32 - no_bits);
2119 bits &= mask;
2120 uint32_t top_bit = 1U << (no_bits - 1);
2121 int32_t as_signed = static_cast<int32_t>(bits);
2122 return (bits & top_bit) ? as_signed + (-top_bit * 2) : as_signed;
2125 // Detects overflow of an NO_BITS integer stored in a uint32_t.
2126 template<int no_bits>
2127 static inline bool
2128 has_overflow(uint32_t bits)
2130 gold_assert(no_bits >= 0 && no_bits <= 32);
2131 if (no_bits == 32)
2132 return false;
2133 int32_t max = (1 << (no_bits - 1)) - 1;
2134 int32_t min = -(1 << (no_bits - 1));
2135 int32_t as_signed = static_cast<int32_t>(bits);
2136 return as_signed > max || as_signed < min;
2139 // Detects overflow of an NO_BITS integer stored in a uint32_t when it
2140 // fits in the given number of bits as either a signed or unsigned value.
2141 // For example, has_signed_unsigned_overflow<8> would check
2142 // -128 <= bits <= 255
2143 template<int no_bits>
2144 static inline bool
2145 has_signed_unsigned_overflow(uint32_t bits)
2147 gold_assert(no_bits >= 2 && no_bits <= 32);
2148 if (no_bits == 32)
2149 return false;
2150 int32_t max = static_cast<int32_t>((1U << no_bits) - 1);
2151 int32_t min = -(1 << (no_bits - 1));
2152 int32_t as_signed = static_cast<int32_t>(bits);
2153 return as_signed > max || as_signed < min;
2156 // Select bits from A and B using bits in MASK. For each n in [0..31],
2157 // the n-th bit in the result is chosen from the n-th bits of A and B.
2158 // A zero selects A and a one selects B.
2159 static inline uint32_t
2160 bit_select(uint32_t a, uint32_t b, uint32_t mask)
2161 { return (a & ~mask) | (b & mask); }
2164 template<bool big_endian>
2165 class Target_arm : public Sized_target<32, big_endian>
2167 public:
2168 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
2169 Reloc_section;
2171 // When were are relocating a stub, we pass this as the relocation number.
2172 static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
2174 Target_arm()
2175 : Sized_target<32, big_endian>(&arm_info),
2176 got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
2177 copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL),
2178 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2179 stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2180 may_use_blx_(false), should_force_pic_veneer_(false),
2181 arm_input_section_map_(), attributes_section_data_(NULL),
2182 fix_cortex_a8_(false), cortex_a8_relocs_info_()
2185 // Virtual function which is set to return true by a target if
2186 // it can use relocation types to determine if a function's
2187 // pointer is taken.
2188 virtual bool
2189 can_check_for_function_pointers() const
2190 { return true; }
2192 // Whether a section called SECTION_NAME may have function pointers to
2193 // sections not eligible for safe ICF folding.
2194 virtual bool
2195 section_may_have_icf_unsafe_pointers(const char* section_name) const
2197 return (!is_prefix_of(".ARM.exidx", section_name)
2198 && !is_prefix_of(".ARM.extab", section_name)
2199 && Target::section_may_have_icf_unsafe_pointers(section_name));
2202 // Whether we can use BLX.
2203 bool
2204 may_use_blx() const
2205 { return this->may_use_blx_; }
2207 // Set use-BLX flag.
2208 void
2209 set_may_use_blx(bool value)
2210 { this->may_use_blx_ = value; }
2212 // Whether we force PCI branch veneers.
2213 bool
2214 should_force_pic_veneer() const
2215 { return this->should_force_pic_veneer_; }
2217 // Set PIC veneer flag.
2218 void
2219 set_should_force_pic_veneer(bool value)
2220 { this->should_force_pic_veneer_ = value; }
2222 // Whether we use THUMB-2 instructions.
2223 bool
2224 using_thumb2() const
2226 Object_attribute* attr =
2227 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2228 int arch = attr->int_value();
2229 return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2232 // Whether we use THUMB/THUMB-2 instructions only.
2233 bool
2234 using_thumb_only() const
2236 Object_attribute* attr =
2237 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2239 if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M
2240 || attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M)
2241 return true;
2242 if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2243 && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2244 return false;
2245 attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2246 return attr->int_value() == 'M';
2249 // Whether we have an NOP instruction. If not, use mov r0, r0 instead.
2250 bool
2251 may_use_arm_nop() const
2253 Object_attribute* attr =
2254 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2255 int arch = attr->int_value();
2256 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2257 || arch == elfcpp::TAG_CPU_ARCH_V6K
2258 || arch == elfcpp::TAG_CPU_ARCH_V7
2259 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2262 // Whether we have THUMB-2 NOP.W instruction.
2263 bool
2264 may_use_thumb2_nop() const
2266 Object_attribute* attr =
2267 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2268 int arch = attr->int_value();
2269 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2270 || arch == elfcpp::TAG_CPU_ARCH_V7
2271 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2274 // Process the relocations to determine unreferenced sections for
2275 // garbage collection.
2276 void
2277 gc_process_relocs(Symbol_table* symtab,
2278 Layout* layout,
2279 Sized_relobj_file<32, big_endian>* object,
2280 unsigned int data_shndx,
2281 unsigned int sh_type,
2282 const unsigned char* prelocs,
2283 size_t reloc_count,
2284 Output_section* output_section,
2285 bool needs_special_offset_handling,
2286 size_t local_symbol_count,
2287 const unsigned char* plocal_symbols);
2289 // Scan the relocations to look for symbol adjustments.
2290 void
2291 scan_relocs(Symbol_table* symtab,
2292 Layout* layout,
2293 Sized_relobj_file<32, big_endian>* object,
2294 unsigned int data_shndx,
2295 unsigned int sh_type,
2296 const unsigned char* prelocs,
2297 size_t reloc_count,
2298 Output_section* output_section,
2299 bool needs_special_offset_handling,
2300 size_t local_symbol_count,
2301 const unsigned char* plocal_symbols);
2303 // Finalize the sections.
2304 void
2305 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2307 // Return the value to use for a dynamic symbol which requires special
2308 // treatment.
2309 uint64_t
2310 do_dynsym_value(const Symbol*) const;
2312 // Relocate a section.
2313 void
2314 relocate_section(const Relocate_info<32, big_endian>*,
2315 unsigned int sh_type,
2316 const unsigned char* prelocs,
2317 size_t reloc_count,
2318 Output_section* output_section,
2319 bool needs_special_offset_handling,
2320 unsigned char* view,
2321 Arm_address view_address,
2322 section_size_type view_size,
2323 const Reloc_symbol_changes*);
2325 // Scan the relocs during a relocatable link.
2326 void
2327 scan_relocatable_relocs(Symbol_table* symtab,
2328 Layout* layout,
2329 Sized_relobj_file<32, big_endian>* object,
2330 unsigned int data_shndx,
2331 unsigned int sh_type,
2332 const unsigned char* prelocs,
2333 size_t reloc_count,
2334 Output_section* output_section,
2335 bool needs_special_offset_handling,
2336 size_t local_symbol_count,
2337 const unsigned char* plocal_symbols,
2338 Relocatable_relocs*);
2340 // Relocate a section during a relocatable link.
2341 void
2342 relocate_for_relocatable(const Relocate_info<32, big_endian>*,
2343 unsigned int sh_type,
2344 const unsigned char* prelocs,
2345 size_t reloc_count,
2346 Output_section* output_section,
2347 off_t offset_in_output_section,
2348 const Relocatable_relocs*,
2349 unsigned char* view,
2350 Arm_address view_address,
2351 section_size_type view_size,
2352 unsigned char* reloc_view,
2353 section_size_type reloc_view_size);
2355 // Perform target-specific processing in a relocatable link. This is
2356 // only used if we use the relocation strategy RELOC_SPECIAL.
2357 void
2358 relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2359 unsigned int sh_type,
2360 const unsigned char* preloc_in,
2361 size_t relnum,
2362 Output_section* output_section,
2363 off_t offset_in_output_section,
2364 unsigned char* view,
2365 typename elfcpp::Elf_types<32>::Elf_Addr
2366 view_address,
2367 section_size_type view_size,
2368 unsigned char* preloc_out);
2370 // Return whether SYM is defined by the ABI.
2371 bool
2372 do_is_defined_by_abi(Symbol* sym) const
2373 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2375 // Return whether there is a GOT section.
2376 bool
2377 has_got_section() const
2378 { return this->got_ != NULL; }
2380 // Return the size of the GOT section.
2381 section_size_type
2382 got_size() const
2384 gold_assert(this->got_ != NULL);
2385 return this->got_->data_size();
2388 // Return the number of entries in the GOT.
2389 unsigned int
2390 got_entry_count() const
2392 if (!this->has_got_section())
2393 return 0;
2394 return this->got_size() / 4;
2397 // Return the number of entries in the PLT.
2398 unsigned int
2399 plt_entry_count() const;
2401 // Return the offset of the first non-reserved PLT entry.
2402 unsigned int
2403 first_plt_entry_offset() const;
2405 // Return the size of each PLT entry.
2406 unsigned int
2407 plt_entry_size() const;
2409 // Map platform-specific reloc types
2410 static unsigned int
2411 get_real_reloc_type(unsigned int r_type);
2414 // Methods to support stub-generations.
2417 // Return the stub factory
2418 const Stub_factory&
2419 stub_factory() const
2420 { return this->stub_factory_; }
2422 // Make a new Arm_input_section object.
2423 Arm_input_section<big_endian>*
2424 new_arm_input_section(Relobj*, unsigned int);
2426 // Find the Arm_input_section object corresponding to the SHNDX-th input
2427 // section of RELOBJ.
2428 Arm_input_section<big_endian>*
2429 find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2431 // Make a new Stub_table
2432 Stub_table<big_endian>*
2433 new_stub_table(Arm_input_section<big_endian>*);
2435 // Scan a section for stub generation.
2436 void
2437 scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2438 const unsigned char*, size_t, Output_section*,
2439 bool, const unsigned char*, Arm_address,
2440 section_size_type);
2442 // Relocate a stub.
2443 void
2444 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2445 Output_section*, unsigned char*, Arm_address,
2446 section_size_type);
2448 // Get the default ARM target.
2449 static Target_arm<big_endian>*
2450 default_target()
2452 gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2453 && parameters->target().is_big_endian() == big_endian);
2454 return static_cast<Target_arm<big_endian>*>(
2455 parameters->sized_target<32, big_endian>());
2458 // Whether NAME belongs to a mapping symbol.
2459 static bool
2460 is_mapping_symbol_name(const char* name)
2462 return (name
2463 && name[0] == '$'
2464 && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2465 && (name[2] == '\0' || name[2] == '.'));
2468 // Whether we work around the Cortex-A8 erratum.
2469 bool
2470 fix_cortex_a8() const
2471 { return this->fix_cortex_a8_; }
2473 // Whether we merge exidx entries in debuginfo.
2474 bool
2475 merge_exidx_entries() const
2476 { return parameters->options().merge_exidx_entries(); }
2478 // Whether we fix R_ARM_V4BX relocation.
2479 // 0 - do not fix
2480 // 1 - replace with MOV instruction (armv4 target)
2481 // 2 - make interworking veneer (>= armv4t targets only)
2482 General_options::Fix_v4bx
2483 fix_v4bx() const
2484 { return parameters->options().fix_v4bx(); }
2486 // Scan a span of THUMB code section for Cortex-A8 erratum.
2487 void
2488 scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2489 section_size_type, section_size_type,
2490 const unsigned char*, Arm_address);
2492 // Apply Cortex-A8 workaround to a branch.
2493 void
2494 apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2495 unsigned char*, Arm_address);
2497 protected:
2498 // Make an ELF object.
2499 Object*
2500 do_make_elf_object(const std::string&, Input_file*, off_t,
2501 const elfcpp::Ehdr<32, big_endian>& ehdr);
2503 Object*
2504 do_make_elf_object(const std::string&, Input_file*, off_t,
2505 const elfcpp::Ehdr<32, !big_endian>&)
2506 { gold_unreachable(); }
2508 Object*
2509 do_make_elf_object(const std::string&, Input_file*, off_t,
2510 const elfcpp::Ehdr<64, false>&)
2511 { gold_unreachable(); }
2513 Object*
2514 do_make_elf_object(const std::string&, Input_file*, off_t,
2515 const elfcpp::Ehdr<64, true>&)
2516 { gold_unreachable(); }
2518 // Make an output section.
2519 Output_section*
2520 do_make_output_section(const char* name, elfcpp::Elf_Word type,
2521 elfcpp::Elf_Xword flags)
2522 { return new Arm_output_section<big_endian>(name, type, flags); }
2524 void
2525 do_adjust_elf_header(unsigned char* view, int len) const;
2527 // We only need to generate stubs, and hence perform relaxation if we are
2528 // not doing relocatable linking.
2529 bool
2530 do_may_relax() const
2531 { return !parameters->options().relocatable(); }
2533 bool
2534 do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
2536 // Determine whether an object attribute tag takes an integer, a
2537 // string or both.
2539 do_attribute_arg_type(int tag) const;
2541 // Reorder tags during output.
2543 do_attributes_order(int num) const;
2545 // This is called when the target is selected as the default.
2546 void
2547 do_select_as_default_target()
2549 // No locking is required since there should only be one default target.
2550 // We cannot have both the big-endian and little-endian ARM targets
2551 // as the default.
2552 gold_assert(arm_reloc_property_table == NULL);
2553 arm_reloc_property_table = new Arm_reloc_property_table();
2556 private:
2557 // The class which scans relocations.
2558 class Scan
2560 public:
2561 Scan()
2562 : issued_non_pic_error_(false)
2565 static inline int
2566 get_reference_flags(unsigned int r_type);
2568 inline void
2569 local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2570 Sized_relobj_file<32, big_endian>* object,
2571 unsigned int data_shndx,
2572 Output_section* output_section,
2573 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2574 const elfcpp::Sym<32, big_endian>& lsym);
2576 inline void
2577 global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2578 Sized_relobj_file<32, big_endian>* object,
2579 unsigned int data_shndx,
2580 Output_section* output_section,
2581 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2582 Symbol* gsym);
2584 inline bool
2585 local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2586 Sized_relobj_file<32, big_endian>* ,
2587 unsigned int ,
2588 Output_section* ,
2589 const elfcpp::Rel<32, big_endian>& ,
2590 unsigned int ,
2591 const elfcpp::Sym<32, big_endian>&);
2593 inline bool
2594 global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2595 Sized_relobj_file<32, big_endian>* ,
2596 unsigned int ,
2597 Output_section* ,
2598 const elfcpp::Rel<32, big_endian>& ,
2599 unsigned int , Symbol*);
2601 private:
2602 static void
2603 unsupported_reloc_local(Sized_relobj_file<32, big_endian>*,
2604 unsigned int r_type);
2606 static void
2607 unsupported_reloc_global(Sized_relobj_file<32, big_endian>*,
2608 unsigned int r_type, Symbol*);
2610 void
2611 check_non_pic(Relobj*, unsigned int r_type);
2613 // Almost identical to Symbol::needs_plt_entry except that it also
2614 // handles STT_ARM_TFUNC.
2615 static bool
2616 symbol_needs_plt_entry(const Symbol* sym)
2618 // An undefined symbol from an executable does not need a PLT entry.
2619 if (sym->is_undefined() && !parameters->options().shared())
2620 return false;
2622 return (!parameters->doing_static_link()
2623 && (sym->type() == elfcpp::STT_FUNC
2624 || sym->type() == elfcpp::STT_ARM_TFUNC)
2625 && (sym->is_from_dynobj()
2626 || sym->is_undefined()
2627 || sym->is_preemptible()));
2630 inline bool
2631 possible_function_pointer_reloc(unsigned int r_type);
2633 // Whether we have issued an error about a non-PIC compilation.
2634 bool issued_non_pic_error_;
2637 // The class which implements relocation.
2638 class Relocate
2640 public:
2641 Relocate()
2644 ~Relocate()
2647 // Return whether the static relocation needs to be applied.
2648 inline bool
2649 should_apply_static_reloc(const Sized_symbol<32>* gsym,
2650 unsigned int r_type,
2651 bool is_32bit,
2652 Output_section* output_section);
2654 // Do a relocation. Return false if the caller should not issue
2655 // any warnings about this relocation.
2656 inline bool
2657 relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2658 Output_section*, size_t relnum,
2659 const elfcpp::Rel<32, big_endian>&,
2660 unsigned int r_type, const Sized_symbol<32>*,
2661 const Symbol_value<32>*,
2662 unsigned char*, Arm_address,
2663 section_size_type);
2665 // Return whether we want to pass flag NON_PIC_REF for this
2666 // reloc. This means the relocation type accesses a symbol not via
2667 // GOT or PLT.
2668 static inline bool
2669 reloc_is_non_pic(unsigned int r_type)
2671 switch (r_type)
2673 // These relocation types reference GOT or PLT entries explicitly.
2674 case elfcpp::R_ARM_GOT_BREL:
2675 case elfcpp::R_ARM_GOT_ABS:
2676 case elfcpp::R_ARM_GOT_PREL:
2677 case elfcpp::R_ARM_GOT_BREL12:
2678 case elfcpp::R_ARM_PLT32_ABS:
2679 case elfcpp::R_ARM_TLS_GD32:
2680 case elfcpp::R_ARM_TLS_LDM32:
2681 case elfcpp::R_ARM_TLS_IE32:
2682 case elfcpp::R_ARM_TLS_IE12GP:
2684 // These relocate types may use PLT entries.
2685 case elfcpp::R_ARM_CALL:
2686 case elfcpp::R_ARM_THM_CALL:
2687 case elfcpp::R_ARM_JUMP24:
2688 case elfcpp::R_ARM_THM_JUMP24:
2689 case elfcpp::R_ARM_THM_JUMP19:
2690 case elfcpp::R_ARM_PLT32:
2691 case elfcpp::R_ARM_THM_XPC22:
2692 case elfcpp::R_ARM_PREL31:
2693 case elfcpp::R_ARM_SBREL31:
2694 return false;
2696 default:
2697 return true;
2701 private:
2702 // Do a TLS relocation.
2703 inline typename Arm_relocate_functions<big_endian>::Status
2704 relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2705 size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2706 const Sized_symbol<32>*, const Symbol_value<32>*,
2707 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2708 section_size_type);
2712 // A class which returns the size required for a relocation type,
2713 // used while scanning relocs during a relocatable link.
2714 class Relocatable_size_for_reloc
2716 public:
2717 unsigned int
2718 get_size_for_reloc(unsigned int, Relobj*);
2721 // Adjust TLS relocation type based on the options and whether this
2722 // is a local symbol.
2723 static tls::Tls_optimization
2724 optimize_tls_reloc(bool is_final, int r_type);
2726 // Get the GOT section, creating it if necessary.
2727 Arm_output_data_got<big_endian>*
2728 got_section(Symbol_table*, Layout*);
2730 // Get the GOT PLT section.
2731 Output_data_space*
2732 got_plt_section() const
2734 gold_assert(this->got_plt_ != NULL);
2735 return this->got_plt_;
2738 // Create a PLT entry for a global symbol.
2739 void
2740 make_plt_entry(Symbol_table*, Layout*, Symbol*);
2742 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2743 void
2744 define_tls_base_symbol(Symbol_table*, Layout*);
2746 // Create a GOT entry for the TLS module index.
2747 unsigned int
2748 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2749 Sized_relobj_file<32, big_endian>* object);
2751 // Get the PLT section.
2752 const Output_data_plt_arm<big_endian>*
2753 plt_section() const
2755 gold_assert(this->plt_ != NULL);
2756 return this->plt_;
2759 // Get the dynamic reloc section, creating it if necessary.
2760 Reloc_section*
2761 rel_dyn_section(Layout*);
2763 // Get the section to use for TLS_DESC relocations.
2764 Reloc_section*
2765 rel_tls_desc_section(Layout*) const;
2767 // Return true if the symbol may need a COPY relocation.
2768 // References from an executable object to non-function symbols
2769 // defined in a dynamic object may need a COPY relocation.
2770 bool
2771 may_need_copy_reloc(Symbol* gsym)
2773 return (gsym->type() != elfcpp::STT_ARM_TFUNC
2774 && gsym->may_need_copy_reloc());
2777 // Add a potential copy relocation.
2778 void
2779 copy_reloc(Symbol_table* symtab, Layout* layout,
2780 Sized_relobj_file<32, big_endian>* object,
2781 unsigned int shndx, Output_section* output_section,
2782 Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2784 this->copy_relocs_.copy_reloc(symtab, layout,
2785 symtab->get_sized_symbol<32>(sym),
2786 object, shndx, output_section, reloc,
2787 this->rel_dyn_section(layout));
2790 // Whether two EABI versions are compatible.
2791 static bool
2792 are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2794 // Merge processor-specific flags from input object and those in the ELF
2795 // header of the output.
2796 void
2797 merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2799 // Get the secondary compatible architecture.
2800 static int
2801 get_secondary_compatible_arch(const Attributes_section_data*);
2803 // Set the secondary compatible architecture.
2804 static void
2805 set_secondary_compatible_arch(Attributes_section_data*, int);
2807 static int
2808 tag_cpu_arch_combine(const char*, int, int*, int, int);
2810 // Helper to print AEABI enum tag value.
2811 static std::string
2812 aeabi_enum_name(unsigned int);
2814 // Return string value for TAG_CPU_name.
2815 static std::string
2816 tag_cpu_name_value(unsigned int);
2818 // Merge object attributes from input object and those in the output.
2819 void
2820 merge_object_attributes(const char*, const Attributes_section_data*);
2822 // Helper to get an AEABI object attribute
2823 Object_attribute*
2824 get_aeabi_object_attribute(int tag) const
2826 Attributes_section_data* pasd = this->attributes_section_data_;
2827 gold_assert(pasd != NULL);
2828 Object_attribute* attr =
2829 pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2830 gold_assert(attr != NULL);
2831 return attr;
2835 // Methods to support stub-generations.
2838 // Group input sections for stub generation.
2839 void
2840 group_sections(Layout*, section_size_type, bool, const Task*);
2842 // Scan a relocation for stub generation.
2843 void
2844 scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2845 const Sized_symbol<32>*, unsigned int,
2846 const Symbol_value<32>*,
2847 elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2849 // Scan a relocation section for stub.
2850 template<int sh_type>
2851 void
2852 scan_reloc_section_for_stubs(
2853 const Relocate_info<32, big_endian>* relinfo,
2854 const unsigned char* prelocs,
2855 size_t reloc_count,
2856 Output_section* output_section,
2857 bool needs_special_offset_handling,
2858 const unsigned char* view,
2859 elfcpp::Elf_types<32>::Elf_Addr view_address,
2860 section_size_type);
2862 // Fix .ARM.exidx section coverage.
2863 void
2864 fix_exidx_coverage(Layout*, const Input_objects*,
2865 Arm_output_section<big_endian>*, Symbol_table*,
2866 const Task*);
2868 // Functors for STL set.
2869 struct output_section_address_less_than
2871 bool
2872 operator()(const Output_section* s1, const Output_section* s2) const
2873 { return s1->address() < s2->address(); }
2876 // Information about this specific target which we pass to the
2877 // general Target structure.
2878 static const Target::Target_info arm_info;
2880 // The types of GOT entries needed for this platform.
2881 // These values are exposed to the ABI in an incremental link.
2882 // Do not renumber existing values without changing the version
2883 // number of the .gnu_incremental_inputs section.
2884 enum Got_type
2886 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
2887 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
2888 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
2889 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
2890 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
2893 typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2895 // Map input section to Arm_input_section.
2896 typedef Unordered_map<Section_id,
2897 Arm_input_section<big_endian>*,
2898 Section_id_hash>
2899 Arm_input_section_map;
2901 // Map output addresses to relocs for Cortex-A8 erratum.
2902 typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2903 Cortex_a8_relocs_info;
2905 // The GOT section.
2906 Arm_output_data_got<big_endian>* got_;
2907 // The PLT section.
2908 Output_data_plt_arm<big_endian>* plt_;
2909 // The GOT PLT section.
2910 Output_data_space* got_plt_;
2911 // The dynamic reloc section.
2912 Reloc_section* rel_dyn_;
2913 // Relocs saved to avoid a COPY reloc.
2914 Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2915 // Space for variables copied with a COPY reloc.
2916 Output_data_space* dynbss_;
2917 // Offset of the GOT entry for the TLS module index.
2918 unsigned int got_mod_index_offset_;
2919 // True if the _TLS_MODULE_BASE_ symbol has been defined.
2920 bool tls_base_symbol_defined_;
2921 // Vector of Stub_tables created.
2922 Stub_table_list stub_tables_;
2923 // Stub factory.
2924 const Stub_factory &stub_factory_;
2925 // Whether we can use BLX.
2926 bool may_use_blx_;
2927 // Whether we force PIC branch veneers.
2928 bool should_force_pic_veneer_;
2929 // Map for locating Arm_input_sections.
2930 Arm_input_section_map arm_input_section_map_;
2931 // Attributes section data in output.
2932 Attributes_section_data* attributes_section_data_;
2933 // Whether we want to fix code for Cortex-A8 erratum.
2934 bool fix_cortex_a8_;
2935 // Map addresses to relocs for Cortex-A8 erratum.
2936 Cortex_a8_relocs_info cortex_a8_relocs_info_;
2939 template<bool big_endian>
2940 const Target::Target_info Target_arm<big_endian>::arm_info =
2942 32, // size
2943 big_endian, // is_big_endian
2944 elfcpp::EM_ARM, // machine_code
2945 false, // has_make_symbol
2946 false, // has_resolve
2947 false, // has_code_fill
2948 true, // is_default_stack_executable
2949 '\0', // wrap_char
2950 "/usr/lib/libc.so.1", // dynamic_linker
2951 0x8000, // default_text_segment_address
2952 0x1000, // abi_pagesize (overridable by -z max-page-size)
2953 0x1000, // common_pagesize (overridable by -z common-page-size)
2954 elfcpp::SHN_UNDEF, // small_common_shndx
2955 elfcpp::SHN_UNDEF, // large_common_shndx
2956 0, // small_common_section_flags
2957 0, // large_common_section_flags
2958 ".ARM.attributes", // attributes_section
2959 "aeabi" // attributes_vendor
2962 // Arm relocate functions class
2965 template<bool big_endian>
2966 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2968 public:
2969 typedef enum
2971 STATUS_OKAY, // No error during relocation.
2972 STATUS_OVERFLOW, // Relocation overflow.
2973 STATUS_BAD_RELOC // Relocation cannot be applied.
2974 } Status;
2976 private:
2977 typedef Relocate_functions<32, big_endian> Base;
2978 typedef Arm_relocate_functions<big_endian> This;
2980 // Encoding of imm16 argument for movt and movw ARM instructions
2981 // from ARM ARM:
2983 // imm16 := imm4 | imm12
2985 // 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
2986 // +-------+---------------+-------+-------+-----------------------+
2987 // | | |imm4 | |imm12 |
2988 // +-------+---------------+-------+-------+-----------------------+
2990 // Extract the relocation addend from VAL based on the ARM
2991 // instruction encoding described above.
2992 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2993 extract_arm_movw_movt_addend(
2994 typename elfcpp::Swap<32, big_endian>::Valtype val)
2996 // According to the Elf ABI for ARM Architecture the immediate
2997 // field is sign-extended to form the addend.
2998 return utils::sign_extend<16>(((val >> 4) & 0xf000) | (val & 0xfff));
3001 // Insert X into VAL based on the ARM instruction encoding described
3002 // above.
3003 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3004 insert_val_arm_movw_movt(
3005 typename elfcpp::Swap<32, big_endian>::Valtype val,
3006 typename elfcpp::Swap<32, big_endian>::Valtype x)
3008 val &= 0xfff0f000;
3009 val |= x & 0x0fff;
3010 val |= (x & 0xf000) << 4;
3011 return val;
3014 // Encoding of imm16 argument for movt and movw Thumb2 instructions
3015 // from ARM ARM:
3017 // imm16 := imm4 | i | imm3 | imm8
3019 // 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
3020 // +---------+-+-----------+-------++-+-----+-------+---------------+
3021 // | |i| |imm4 || |imm3 | |imm8 |
3022 // +---------+-+-----------+-------++-+-----+-------+---------------+
3024 // Extract the relocation addend from VAL based on the Thumb2
3025 // instruction encoding described above.
3026 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3027 extract_thumb_movw_movt_addend(
3028 typename elfcpp::Swap<32, big_endian>::Valtype val)
3030 // According to the Elf ABI for ARM Architecture the immediate
3031 // field is sign-extended to form the addend.
3032 return utils::sign_extend<16>(((val >> 4) & 0xf000)
3033 | ((val >> 15) & 0x0800)
3034 | ((val >> 4) & 0x0700)
3035 | (val & 0x00ff));
3038 // Insert X into VAL based on the Thumb2 instruction encoding
3039 // described above.
3040 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3041 insert_val_thumb_movw_movt(
3042 typename elfcpp::Swap<32, big_endian>::Valtype val,
3043 typename elfcpp::Swap<32, big_endian>::Valtype x)
3045 val &= 0xfbf08f00;
3046 val |= (x & 0xf000) << 4;
3047 val |= (x & 0x0800) << 15;
3048 val |= (x & 0x0700) << 4;
3049 val |= (x & 0x00ff);
3050 return val;
3053 // Calculate the smallest constant Kn for the specified residual.
3054 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3055 static uint32_t
3056 calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3058 int32_t msb;
3060 if (residual == 0)
3061 return 0;
3062 // Determine the most significant bit in the residual and
3063 // align the resulting value to a 2-bit boundary.
3064 for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3066 // The desired shift is now (msb - 6), or zero, whichever
3067 // is the greater.
3068 return (((msb - 6) < 0) ? 0 : (msb - 6));
3071 // Calculate the final residual for the specified group index.
3072 // If the passed group index is less than zero, the method will return
3073 // the value of the specified residual without any change.
3074 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3075 static typename elfcpp::Swap<32, big_endian>::Valtype
3076 calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3077 const int group)
3079 for (int n = 0; n <= group; n++)
3081 // Calculate which part of the value to mask.
3082 uint32_t shift = calc_grp_kn(residual);
3083 // Calculate the residual for the next time around.
3084 residual &= ~(residual & (0xff << shift));
3087 return residual;
3090 // Calculate the value of Gn for the specified group index.
3091 // We return it in the form of an encoded constant-and-rotation.
3092 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3093 static typename elfcpp::Swap<32, big_endian>::Valtype
3094 calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3095 const int group)
3097 typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3098 uint32_t shift = 0;
3100 for (int n = 0; n <= group; n++)
3102 // Calculate which part of the value to mask.
3103 shift = calc_grp_kn(residual);
3104 // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3105 gn = residual & (0xff << shift);
3106 // Calculate the residual for the next time around.
3107 residual &= ~gn;
3109 // Return Gn in the form of an encoded constant-and-rotation.
3110 return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3113 public:
3114 // Handle ARM long branches.
3115 static typename This::Status
3116 arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3117 unsigned char*, const Sized_symbol<32>*,
3118 const Arm_relobj<big_endian>*, unsigned int,
3119 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3121 // Handle THUMB long branches.
3122 static typename This::Status
3123 thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3124 unsigned char*, const Sized_symbol<32>*,
3125 const Arm_relobj<big_endian>*, unsigned int,
3126 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3129 // Return the branch offset of a 32-bit THUMB branch.
3130 static inline int32_t
3131 thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3133 // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3134 // involving the J1 and J2 bits.
3135 uint32_t s = (upper_insn & (1U << 10)) >> 10;
3136 uint32_t upper = upper_insn & 0x3ffU;
3137 uint32_t lower = lower_insn & 0x7ffU;
3138 uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3139 uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3140 uint32_t i1 = j1 ^ s ? 0 : 1;
3141 uint32_t i2 = j2 ^ s ? 0 : 1;
3143 return utils::sign_extend<25>((s << 24) | (i1 << 23) | (i2 << 22)
3144 | (upper << 12) | (lower << 1));
3147 // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3148 // UPPER_INSN is the original upper instruction of the branch. Caller is
3149 // responsible for overflow checking and BLX offset adjustment.
3150 static inline uint16_t
3151 thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3153 uint32_t s = offset < 0 ? 1 : 0;
3154 uint32_t bits = static_cast<uint32_t>(offset);
3155 return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3158 // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3159 // LOWER_INSN is the original lower instruction of the branch. Caller is
3160 // responsible for overflow checking and BLX offset adjustment.
3161 static inline uint16_t
3162 thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3164 uint32_t s = offset < 0 ? 1 : 0;
3165 uint32_t bits = static_cast<uint32_t>(offset);
3166 return ((lower_insn & ~0x2fffU)
3167 | ((((bits >> 23) & 1) ^ !s) << 13)
3168 | ((((bits >> 22) & 1) ^ !s) << 11)
3169 | ((bits >> 1) & 0x7ffU));
3172 // Return the branch offset of a 32-bit THUMB conditional branch.
3173 static inline int32_t
3174 thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3176 uint32_t s = (upper_insn & 0x0400U) >> 10;
3177 uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3178 uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3179 uint32_t lower = (lower_insn & 0x07ffU);
3180 uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3182 return utils::sign_extend<21>((upper << 12) | (lower << 1));
3185 // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3186 // instruction. UPPER_INSN is the original upper instruction of the branch.
3187 // Caller is responsible for overflow checking.
3188 static inline uint16_t
3189 thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3191 uint32_t s = offset < 0 ? 1 : 0;
3192 uint32_t bits = static_cast<uint32_t>(offset);
3193 return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3196 // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3197 // instruction. LOWER_INSN is the original lower instruction of the branch.
3198 // The caller is responsible for overflow checking.
3199 static inline uint16_t
3200 thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3202 uint32_t bits = static_cast<uint32_t>(offset);
3203 uint32_t j2 = (bits & 0x00080000U) >> 19;
3204 uint32_t j1 = (bits & 0x00040000U) >> 18;
3205 uint32_t lo = (bits & 0x00000ffeU) >> 1;
3207 return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3210 // R_ARM_ABS8: S + A
3211 static inline typename This::Status
3212 abs8(unsigned char* view,
3213 const Sized_relobj_file<32, big_endian>* object,
3214 const Symbol_value<32>* psymval)
3216 typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3217 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3218 Valtype* wv = reinterpret_cast<Valtype*>(view);
3219 Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3220 Reltype addend = utils::sign_extend<8>(val);
3221 Reltype x = psymval->value(object, addend);
3222 val = utils::bit_select(val, x, 0xffU);
3223 elfcpp::Swap<8, big_endian>::writeval(wv, val);
3225 // R_ARM_ABS8 permits signed or unsigned results.
3226 int signed_x = static_cast<int32_t>(x);
3227 return ((signed_x < -128 || signed_x > 255)
3228 ? This::STATUS_OVERFLOW
3229 : This::STATUS_OKAY);
3232 // R_ARM_THM_ABS5: S + A
3233 static inline typename This::Status
3234 thm_abs5(unsigned char* view,
3235 const Sized_relobj_file<32, big_endian>* object,
3236 const Symbol_value<32>* psymval)
3238 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3239 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3240 Valtype* wv = reinterpret_cast<Valtype*>(view);
3241 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3242 Reltype addend = (val & 0x7e0U) >> 6;
3243 Reltype x = psymval->value(object, addend);
3244 val = utils::bit_select(val, x << 6, 0x7e0U);
3245 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3247 // R_ARM_ABS16 permits signed or unsigned results.
3248 int signed_x = static_cast<int32_t>(x);
3249 return ((signed_x < -32768 || signed_x > 65535)
3250 ? This::STATUS_OVERFLOW
3251 : This::STATUS_OKAY);
3254 // R_ARM_ABS12: S + A
3255 static inline typename This::Status
3256 abs12(unsigned char* view,
3257 const Sized_relobj_file<32, big_endian>* object,
3258 const Symbol_value<32>* psymval)
3260 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3261 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3262 Valtype* wv = reinterpret_cast<Valtype*>(view);
3263 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3264 Reltype addend = val & 0x0fffU;
3265 Reltype x = psymval->value(object, addend);
3266 val = utils::bit_select(val, x, 0x0fffU);
3267 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3268 return (utils::has_overflow<12>(x)
3269 ? This::STATUS_OVERFLOW
3270 : This::STATUS_OKAY);
3273 // R_ARM_ABS16: S + A
3274 static inline typename This::Status
3275 abs16(unsigned char* view,
3276 const Sized_relobj_file<32, big_endian>* object,
3277 const Symbol_value<32>* psymval)
3279 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3280 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3281 Valtype* wv = reinterpret_cast<Valtype*>(view);
3282 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3283 Reltype addend = utils::sign_extend<16>(val);
3284 Reltype x = psymval->value(object, addend);
3285 val = utils::bit_select(val, x, 0xffffU);
3286 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3287 return (utils::has_signed_unsigned_overflow<16>(x)
3288 ? This::STATUS_OVERFLOW
3289 : This::STATUS_OKAY);
3292 // R_ARM_ABS32: (S + A) | T
3293 static inline typename This::Status
3294 abs32(unsigned char* view,
3295 const Sized_relobj_file<32, big_endian>* object,
3296 const Symbol_value<32>* psymval,
3297 Arm_address thumb_bit)
3299 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3300 Valtype* wv = reinterpret_cast<Valtype*>(view);
3301 Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
3302 Valtype x = psymval->value(object, addend) | thumb_bit;
3303 elfcpp::Swap<32, big_endian>::writeval(wv, x);
3304 return This::STATUS_OKAY;
3307 // R_ARM_REL32: (S + A) | T - P
3308 static inline typename This::Status
3309 rel32(unsigned char* view,
3310 const Sized_relobj_file<32, big_endian>* object,
3311 const Symbol_value<32>* psymval,
3312 Arm_address address,
3313 Arm_address thumb_bit)
3315 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3316 Valtype* wv = reinterpret_cast<Valtype*>(view);
3317 Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
3318 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3319 elfcpp::Swap<32, big_endian>::writeval(wv, x);
3320 return This::STATUS_OKAY;
3323 // R_ARM_THM_JUMP24: (S + A) | T - P
3324 static typename This::Status
3325 thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3326 const Symbol_value<32>* psymval, Arm_address address,
3327 Arm_address thumb_bit);
3329 // R_ARM_THM_JUMP6: S + A – P
3330 static inline typename This::Status
3331 thm_jump6(unsigned char* view,
3332 const Sized_relobj_file<32, big_endian>* object,
3333 const Symbol_value<32>* psymval,
3334 Arm_address address)
3336 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3337 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3338 Valtype* wv = reinterpret_cast<Valtype*>(view);
3339 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3340 // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3341 Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3342 Reltype x = (psymval->value(object, addend) - address);
3343 val = (val & 0xfd07) | ((x & 0x0040) << 3) | ((val & 0x003e) << 2);
3344 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3345 // CZB does only forward jumps.
3346 return ((x > 0x007e)
3347 ? This::STATUS_OVERFLOW
3348 : This::STATUS_OKAY);
3351 // R_ARM_THM_JUMP8: S + A – P
3352 static inline typename This::Status
3353 thm_jump8(unsigned char* view,
3354 const Sized_relobj_file<32, big_endian>* object,
3355 const Symbol_value<32>* psymval,
3356 Arm_address address)
3358 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3359 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3360 Valtype* wv = reinterpret_cast<Valtype*>(view);
3361 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3362 Reltype addend = utils::sign_extend<8>((val & 0x00ff) << 1);
3363 Reltype x = (psymval->value(object, addend) - address);
3364 elfcpp::Swap<16, big_endian>::writeval(wv, (val & 0xff00) | ((x & 0x01fe) >> 1));
3365 return (utils::has_overflow<8>(x)
3366 ? This::STATUS_OVERFLOW
3367 : This::STATUS_OKAY);
3370 // R_ARM_THM_JUMP11: S + A – P
3371 static inline typename This::Status
3372 thm_jump11(unsigned char* view,
3373 const Sized_relobj_file<32, big_endian>* object,
3374 const Symbol_value<32>* psymval,
3375 Arm_address address)
3377 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3378 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3379 Valtype* wv = reinterpret_cast<Valtype*>(view);
3380 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3381 Reltype addend = utils::sign_extend<11>((val & 0x07ff) << 1);
3382 Reltype x = (psymval->value(object, addend) - address);
3383 elfcpp::Swap<16, big_endian>::writeval(wv, (val & 0xf800) | ((x & 0x0ffe) >> 1));
3384 return (utils::has_overflow<11>(x)
3385 ? This::STATUS_OVERFLOW
3386 : This::STATUS_OKAY);
3389 // R_ARM_BASE_PREL: B(S) + A - P
3390 static inline typename This::Status
3391 base_prel(unsigned char* view,
3392 Arm_address origin,
3393 Arm_address address)
3395 Base::rel32(view, origin - address);
3396 return STATUS_OKAY;
3399 // R_ARM_BASE_ABS: B(S) + A
3400 static inline typename This::Status
3401 base_abs(unsigned char* view,
3402 Arm_address origin)
3404 Base::rel32(view, origin);
3405 return STATUS_OKAY;
3408 // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3409 static inline typename This::Status
3410 got_brel(unsigned char* view,
3411 typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3413 Base::rel32(view, got_offset);
3414 return This::STATUS_OKAY;
3417 // R_ARM_GOT_PREL: GOT(S) + A - P
3418 static inline typename This::Status
3419 got_prel(unsigned char* view,
3420 Arm_address got_entry,
3421 Arm_address address)
3423 Base::rel32(view, got_entry - address);
3424 return This::STATUS_OKAY;
3427 // R_ARM_PREL: (S + A) | T - P
3428 static inline typename This::Status
3429 prel31(unsigned char* view,
3430 const Sized_relobj_file<32, big_endian>* object,
3431 const Symbol_value<32>* psymval,
3432 Arm_address address,
3433 Arm_address thumb_bit)
3435 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3436 Valtype* wv = reinterpret_cast<Valtype*>(view);
3437 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3438 Valtype addend = utils::sign_extend<31>(val);
3439 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3440 val = utils::bit_select(val, x, 0x7fffffffU);
3441 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3442 return (utils::has_overflow<31>(x) ?
3443 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3446 // R_ARM_MOVW_ABS_NC: (S + A) | T (relative address base is )
3447 // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3448 // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3449 // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3450 static inline typename This::Status
3451 movw(unsigned char* view,
3452 const Sized_relobj_file<32, big_endian>* object,
3453 const Symbol_value<32>* psymval,
3454 Arm_address relative_address_base,
3455 Arm_address thumb_bit,
3456 bool check_overflow)
3458 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3459 Valtype* wv = reinterpret_cast<Valtype*>(view);
3460 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3461 Valtype addend = This::extract_arm_movw_movt_addend(val);
3462 Valtype x = ((psymval->value(object, addend) | thumb_bit)
3463 - relative_address_base);
3464 val = This::insert_val_arm_movw_movt(val, x);
3465 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3466 return ((check_overflow && utils::has_overflow<16>(x))
3467 ? This::STATUS_OVERFLOW
3468 : This::STATUS_OKAY);
3471 // R_ARM_MOVT_ABS: S + A (relative address base is 0)
3472 // R_ARM_MOVT_PREL: S + A - P
3473 // R_ARM_MOVT_BREL: S + A - B(S)
3474 static inline typename This::Status
3475 movt(unsigned char* view,
3476 const Sized_relobj_file<32, big_endian>* object,
3477 const Symbol_value<32>* psymval,
3478 Arm_address relative_address_base)
3480 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3481 Valtype* wv = reinterpret_cast<Valtype*>(view);
3482 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3483 Valtype addend = This::extract_arm_movw_movt_addend(val);
3484 Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3485 val = This::insert_val_arm_movw_movt(val, x);
3486 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3487 // FIXME: IHI0044D says that we should check for overflow.
3488 return This::STATUS_OKAY;
3491 // R_ARM_THM_MOVW_ABS_NC: S + A | T (relative_address_base is 0)
3492 // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3493 // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3494 // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3495 static inline typename This::Status
3496 thm_movw(unsigned char* view,
3497 const Sized_relobj_file<32, big_endian>* object,
3498 const Symbol_value<32>* psymval,
3499 Arm_address relative_address_base,
3500 Arm_address thumb_bit,
3501 bool check_overflow)
3503 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3504 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3505 Valtype* wv = reinterpret_cast<Valtype*>(view);
3506 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3507 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3508 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3509 Reltype x =
3510 (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3511 val = This::insert_val_thumb_movw_movt(val, x);
3512 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3513 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3514 return ((check_overflow && utils::has_overflow<16>(x))
3515 ? This::STATUS_OVERFLOW
3516 : This::STATUS_OKAY);
3519 // R_ARM_THM_MOVT_ABS: S + A (relative address base is 0)
3520 // R_ARM_THM_MOVT_PREL: S + A - P
3521 // R_ARM_THM_MOVT_BREL: S + A - B(S)
3522 static inline typename This::Status
3523 thm_movt(unsigned char* view,
3524 const Sized_relobj_file<32, big_endian>* object,
3525 const Symbol_value<32>* psymval,
3526 Arm_address relative_address_base)
3528 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3529 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3530 Valtype* wv = reinterpret_cast<Valtype*>(view);
3531 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3532 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3533 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3534 Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3535 val = This::insert_val_thumb_movw_movt(val, x);
3536 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3537 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3538 return This::STATUS_OKAY;
3541 // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3542 static inline typename This::Status
3543 thm_alu11(unsigned char* view,
3544 const Sized_relobj_file<32, big_endian>* object,
3545 const Symbol_value<32>* psymval,
3546 Arm_address address,
3547 Arm_address thumb_bit)
3549 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3550 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3551 Valtype* wv = reinterpret_cast<Valtype*>(view);
3552 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3553 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3555 // 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
3556 // -----------------------------------------------------------------------
3557 // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd |imm8
3558 // ADDW 1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd |imm8
3559 // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd |imm8
3560 // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd |imm8
3561 // SUBW 1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd |imm8
3562 // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd |imm8
3564 // Determine a sign for the addend.
3565 const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3566 || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3567 // Thumb2 addend encoding:
3568 // imm12 := i | imm3 | imm8
3569 int32_t addend = (insn & 0xff)
3570 | ((insn & 0x00007000) >> 4)
3571 | ((insn & 0x04000000) >> 15);
3572 // Apply a sign to the added.
3573 addend *= sign;
3575 int32_t x = (psymval->value(object, addend) | thumb_bit)
3576 - (address & 0xfffffffc);
3577 Reltype val = abs(x);
3578 // Mask out the value and a distinct part of the ADD/SUB opcode
3579 // (bits 7:5 of opword).
3580 insn = (insn & 0xfb0f8f00)
3581 | (val & 0xff)
3582 | ((val & 0x700) << 4)
3583 | ((val & 0x800) << 15);
3584 // Set the opcode according to whether the value to go in the
3585 // place is negative.
3586 if (x < 0)
3587 insn |= 0x00a00000;
3589 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3590 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3591 return ((val > 0xfff) ?
3592 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3595 // R_ARM_THM_PC8: S + A - Pa (Thumb)
3596 static inline typename This::Status
3597 thm_pc8(unsigned char* view,
3598 const Sized_relobj_file<32, big_endian>* object,
3599 const Symbol_value<32>* psymval,
3600 Arm_address address)
3602 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3603 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3604 Valtype* wv = reinterpret_cast<Valtype*>(view);
3605 Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3606 Reltype addend = ((insn & 0x00ff) << 2);
3607 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3608 Reltype val = abs(x);
3609 insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3611 elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3612 return ((val > 0x03fc)
3613 ? This::STATUS_OVERFLOW
3614 : This::STATUS_OKAY);
3617 // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3618 static inline typename This::Status
3619 thm_pc12(unsigned char* view,
3620 const Sized_relobj_file<32, big_endian>* object,
3621 const Symbol_value<32>* psymval,
3622 Arm_address address)
3624 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3625 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3626 Valtype* wv = reinterpret_cast<Valtype*>(view);
3627 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3628 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3629 // Determine a sign for the addend (positive if the U bit is 1).
3630 const int sign = (insn & 0x00800000) ? 1 : -1;
3631 int32_t addend = (insn & 0xfff);
3632 // Apply a sign to the added.
3633 addend *= sign;
3635 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3636 Reltype val = abs(x);
3637 // Mask out and apply the value and the U bit.
3638 insn = (insn & 0xff7ff000) | (val & 0xfff);
3639 // Set the U bit according to whether the value to go in the
3640 // place is positive.
3641 if (x >= 0)
3642 insn |= 0x00800000;
3644 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3645 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3646 return ((val > 0xfff) ?
3647 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3650 // R_ARM_V4BX
3651 static inline typename This::Status
3652 v4bx(const Relocate_info<32, big_endian>* relinfo,
3653 unsigned char* view,
3654 const Arm_relobj<big_endian>* object,
3655 const Arm_address address,
3656 const bool is_interworking)
3659 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3660 Valtype* wv = reinterpret_cast<Valtype*>(view);
3661 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3663 // Ensure that we have a BX instruction.
3664 gold_assert((val & 0x0ffffff0) == 0x012fff10);
3665 const uint32_t reg = (val & 0xf);
3666 if (is_interworking && reg != 0xf)
3668 Stub_table<big_endian>* stub_table =
3669 object->stub_table(relinfo->data_shndx);
3670 gold_assert(stub_table != NULL);
3672 Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3673 gold_assert(stub != NULL);
3675 int32_t veneer_address =
3676 stub_table->address() + stub->offset() - 8 - address;
3677 gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3678 && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3679 // Replace with a branch to veneer (B <addr>)
3680 val = (val & 0xf0000000) | 0x0a000000
3681 | ((veneer_address >> 2) & 0x00ffffff);
3683 else
3685 // Preserve Rm (lowest four bits) and the condition code
3686 // (highest four bits). Other bits encode MOV PC,Rm.
3687 val = (val & 0xf000000f) | 0x01a0f000;
3689 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3690 return This::STATUS_OKAY;
3693 // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3694 // R_ARM_ALU_PC_G0: ((S + A) | T) - P
3695 // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3696 // R_ARM_ALU_PC_G1: ((S + A) | T) - P
3697 // R_ARM_ALU_PC_G2: ((S + A) | T) - P
3698 // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3699 // R_ARM_ALU_SB_G0: ((S + A) | T) - B(S)
3700 // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3701 // R_ARM_ALU_SB_G1: ((S + A) | T) - B(S)
3702 // R_ARM_ALU_SB_G2: ((S + A) | T) - B(S)
3703 static inline typename This::Status
3704 arm_grp_alu(unsigned char* view,
3705 const Sized_relobj_file<32, big_endian>* object,
3706 const Symbol_value<32>* psymval,
3707 const int group,
3708 Arm_address address,
3709 Arm_address thumb_bit,
3710 bool check_overflow)
3712 gold_assert(group >= 0 && group < 3);
3713 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3714 Valtype* wv = reinterpret_cast<Valtype*>(view);
3715 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3717 // ALU group relocations are allowed only for the ADD/SUB instructions.
3718 // (0x00800000 - ADD, 0x00400000 - SUB)
3719 const Valtype opcode = insn & 0x01e00000;
3720 if (opcode != 0x00800000 && opcode != 0x00400000)
3721 return This::STATUS_BAD_RELOC;
3723 // Determine a sign for the addend.
3724 const int sign = (opcode == 0x00800000) ? 1 : -1;
3725 // shifter = rotate_imm * 2
3726 const uint32_t shifter = (insn & 0xf00) >> 7;
3727 // Initial addend value.
3728 int32_t addend = insn & 0xff;
3729 // Rotate addend right by shifter.
3730 addend = (addend >> shifter) | (addend << (32 - shifter));
3731 // Apply a sign to the added.
3732 addend *= sign;
3734 int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3735 Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3736 // Check for overflow if required
3737 if (check_overflow
3738 && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3739 return This::STATUS_OVERFLOW;
3741 // Mask out the value and the ADD/SUB part of the opcode; take care
3742 // not to destroy the S bit.
3743 insn &= 0xff1ff000;
3744 // Set the opcode according to whether the value to go in the
3745 // place is negative.
3746 insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3747 // Encode the offset (encoded Gn).
3748 insn |= gn;
3750 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3751 return This::STATUS_OKAY;
3754 // R_ARM_LDR_PC_G0: S + A - P
3755 // R_ARM_LDR_PC_G1: S + A - P
3756 // R_ARM_LDR_PC_G2: S + A - P
3757 // R_ARM_LDR_SB_G0: S + A - B(S)
3758 // R_ARM_LDR_SB_G1: S + A - B(S)
3759 // R_ARM_LDR_SB_G2: S + A - B(S)
3760 static inline typename This::Status
3761 arm_grp_ldr(unsigned char* view,
3762 const Sized_relobj_file<32, big_endian>* object,
3763 const Symbol_value<32>* psymval,
3764 const int group,
3765 Arm_address address)
3767 gold_assert(group >= 0 && group < 3);
3768 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3769 Valtype* wv = reinterpret_cast<Valtype*>(view);
3770 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3772 const int sign = (insn & 0x00800000) ? 1 : -1;
3773 int32_t addend = (insn & 0xfff) * sign;
3774 int32_t x = (psymval->value(object, addend) - address);
3775 // Calculate the relevant G(n-1) value to obtain this stage residual.
3776 Valtype residual =
3777 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3778 if (residual >= 0x1000)
3779 return This::STATUS_OVERFLOW;
3781 // Mask out the value and U bit.
3782 insn &= 0xff7ff000;
3783 // Set the U bit for non-negative values.
3784 if (x >= 0)
3785 insn |= 0x00800000;
3786 insn |= residual;
3788 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3789 return This::STATUS_OKAY;
3792 // R_ARM_LDRS_PC_G0: S + A - P
3793 // R_ARM_LDRS_PC_G1: S + A - P
3794 // R_ARM_LDRS_PC_G2: S + A - P
3795 // R_ARM_LDRS_SB_G0: S + A - B(S)
3796 // R_ARM_LDRS_SB_G1: S + A - B(S)
3797 // R_ARM_LDRS_SB_G2: S + A - B(S)
3798 static inline typename This::Status
3799 arm_grp_ldrs(unsigned char* view,
3800 const Sized_relobj_file<32, big_endian>* object,
3801 const Symbol_value<32>* psymval,
3802 const int group,
3803 Arm_address address)
3805 gold_assert(group >= 0 && group < 3);
3806 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3807 Valtype* wv = reinterpret_cast<Valtype*>(view);
3808 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3810 const int sign = (insn & 0x00800000) ? 1 : -1;
3811 int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3812 int32_t x = (psymval->value(object, addend) - address);
3813 // Calculate the relevant G(n-1) value to obtain this stage residual.
3814 Valtype residual =
3815 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3816 if (residual >= 0x100)
3817 return This::STATUS_OVERFLOW;
3819 // Mask out the value and U bit.
3820 insn &= 0xff7ff0f0;
3821 // Set the U bit for non-negative values.
3822 if (x >= 0)
3823 insn |= 0x00800000;
3824 insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3826 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3827 return This::STATUS_OKAY;
3830 // R_ARM_LDC_PC_G0: S + A - P
3831 // R_ARM_LDC_PC_G1: S + A - P
3832 // R_ARM_LDC_PC_G2: S + A - P
3833 // R_ARM_LDC_SB_G0: S + A - B(S)
3834 // R_ARM_LDC_SB_G1: S + A - B(S)
3835 // R_ARM_LDC_SB_G2: S + A - B(S)
3836 static inline typename This::Status
3837 arm_grp_ldc(unsigned char* view,
3838 const Sized_relobj_file<32, big_endian>* object,
3839 const Symbol_value<32>* psymval,
3840 const int group,
3841 Arm_address address)
3843 gold_assert(group >= 0 && group < 3);
3844 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3845 Valtype* wv = reinterpret_cast<Valtype*>(view);
3846 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3848 const int sign = (insn & 0x00800000) ? 1 : -1;
3849 int32_t addend = ((insn & 0xff) << 2) * sign;
3850 int32_t x = (psymval->value(object, addend) - address);
3851 // Calculate the relevant G(n-1) value to obtain this stage residual.
3852 Valtype residual =
3853 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3854 if ((residual & 0x3) != 0 || residual >= 0x400)
3855 return This::STATUS_OVERFLOW;
3857 // Mask out the value and U bit.
3858 insn &= 0xff7fff00;
3859 // Set the U bit for non-negative values.
3860 if (x >= 0)
3861 insn |= 0x00800000;
3862 insn |= (residual >> 2);
3864 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3865 return This::STATUS_OKAY;
3869 // Relocate ARM long branches. This handles relocation types
3870 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3871 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3872 // undefined and we do not use PLT in this relocation. In such a case,
3873 // the branch is converted into an NOP.
3875 template<bool big_endian>
3876 typename Arm_relocate_functions<big_endian>::Status
3877 Arm_relocate_functions<big_endian>::arm_branch_common(
3878 unsigned int r_type,
3879 const Relocate_info<32, big_endian>* relinfo,
3880 unsigned char* view,
3881 const Sized_symbol<32>* gsym,
3882 const Arm_relobj<big_endian>* object,
3883 unsigned int r_sym,
3884 const Symbol_value<32>* psymval,
3885 Arm_address address,
3886 Arm_address thumb_bit,
3887 bool is_weakly_undefined_without_plt)
3889 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3890 Valtype* wv = reinterpret_cast<Valtype*>(view);
3891 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3893 bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3894 && ((val & 0x0f000000UL) == 0x0a000000UL);
3895 bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3896 bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3897 && ((val & 0x0f000000UL) == 0x0b000000UL);
3898 bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3899 bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3901 // Check that the instruction is valid.
3902 if (r_type == elfcpp::R_ARM_CALL)
3904 if (!insn_is_uncond_bl && !insn_is_blx)
3905 return This::STATUS_BAD_RELOC;
3907 else if (r_type == elfcpp::R_ARM_JUMP24)
3909 if (!insn_is_b && !insn_is_cond_bl)
3910 return This::STATUS_BAD_RELOC;
3912 else if (r_type == elfcpp::R_ARM_PLT32)
3914 if (!insn_is_any_branch)
3915 return This::STATUS_BAD_RELOC;
3917 else if (r_type == elfcpp::R_ARM_XPC25)
3919 // FIXME: AAELF document IH0044C does not say much about it other
3920 // than it being obsolete.
3921 if (!insn_is_any_branch)
3922 return This::STATUS_BAD_RELOC;
3924 else
3925 gold_unreachable();
3927 // A branch to an undefined weak symbol is turned into a jump to
3928 // the next instruction unless a PLT entry will be created.
3929 // Do the same for local undefined symbols.
3930 // The jump to the next instruction is optimized as a NOP depending
3931 // on the architecture.
3932 const Target_arm<big_endian>* arm_target =
3933 Target_arm<big_endian>::default_target();
3934 if (is_weakly_undefined_without_plt)
3936 gold_assert(!parameters->options().relocatable());
3937 Valtype cond = val & 0xf0000000U;
3938 if (arm_target->may_use_arm_nop())
3939 val = cond | 0x0320f000;
3940 else
3941 val = cond | 0x01a00000; // Using pre-UAL nop: mov r0, r0.
3942 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3943 return This::STATUS_OKAY;
3946 Valtype addend = utils::sign_extend<26>(val << 2);
3947 Valtype branch_target = psymval->value(object, addend);
3948 int32_t branch_offset = branch_target - address;
3950 // We need a stub if the branch offset is too large or if we need
3951 // to switch mode.
3952 bool may_use_blx = arm_target->may_use_blx();
3953 Reloc_stub* stub = NULL;
3955 if (!parameters->options().relocatable()
3956 && (utils::has_overflow<26>(branch_offset)
3957 || ((thumb_bit != 0)
3958 && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3960 Valtype unadjusted_branch_target = psymval->value(object, 0);
3962 Stub_type stub_type =
3963 Reloc_stub::stub_type_for_reloc(r_type, address,
3964 unadjusted_branch_target,
3965 (thumb_bit != 0));
3966 if (stub_type != arm_stub_none)
3968 Stub_table<big_endian>* stub_table =
3969 object->stub_table(relinfo->data_shndx);
3970 gold_assert(stub_table != NULL);
3972 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3973 stub = stub_table->find_reloc_stub(stub_key);
3974 gold_assert(stub != NULL);
3975 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3976 branch_target = stub_table->address() + stub->offset() + addend;
3977 branch_offset = branch_target - address;
3978 gold_assert(!utils::has_overflow<26>(branch_offset));
3982 // At this point, if we still need to switch mode, the instruction
3983 // must either be a BLX or a BL that can be converted to a BLX.
3984 if (thumb_bit != 0)
3986 // Turn BL to BLX.
3987 gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3988 val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3991 val = utils::bit_select(val, (branch_offset >> 2), 0xffffffUL);
3992 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3993 return (utils::has_overflow<26>(branch_offset)
3994 ? This::STATUS_OVERFLOW : This::STATUS_OKAY);
3997 // Relocate THUMB long branches. This handles relocation types
3998 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3999 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
4000 // undefined and we do not use PLT in this relocation. In such a case,
4001 // the branch is converted into an NOP.
4003 template<bool big_endian>
4004 typename Arm_relocate_functions<big_endian>::Status
4005 Arm_relocate_functions<big_endian>::thumb_branch_common(
4006 unsigned int r_type,
4007 const Relocate_info<32, big_endian>* relinfo,
4008 unsigned char* view,
4009 const Sized_symbol<32>* gsym,
4010 const Arm_relobj<big_endian>* object,
4011 unsigned int r_sym,
4012 const Symbol_value<32>* psymval,
4013 Arm_address address,
4014 Arm_address thumb_bit,
4015 bool is_weakly_undefined_without_plt)
4017 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4018 Valtype* wv = reinterpret_cast<Valtype*>(view);
4019 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4020 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4022 // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
4023 // into account.
4024 bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
4025 bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
4027 // Check that the instruction is valid.
4028 if (r_type == elfcpp::R_ARM_THM_CALL)
4030 if (!is_bl_insn && !is_blx_insn)
4031 return This::STATUS_BAD_RELOC;
4033 else if (r_type == elfcpp::R_ARM_THM_JUMP24)
4035 // This cannot be a BLX.
4036 if (!is_bl_insn)
4037 return This::STATUS_BAD_RELOC;
4039 else if (r_type == elfcpp::R_ARM_THM_XPC22)
4041 // Check for Thumb to Thumb call.
4042 if (!is_blx_insn)
4043 return This::STATUS_BAD_RELOC;
4044 if (thumb_bit != 0)
4046 gold_warning(_("%s: Thumb BLX instruction targets "
4047 "thumb function '%s'."),
4048 object->name().c_str(),
4049 (gsym ? gsym->name() : "(local)"));
4050 // Convert BLX to BL.
4051 lower_insn |= 0x1000U;
4054 else
4055 gold_unreachable();
4057 // A branch to an undefined weak symbol is turned into a jump to
4058 // the next instruction unless a PLT entry will be created.
4059 // The jump to the next instruction is optimized as a NOP.W for
4060 // Thumb-2 enabled architectures.
4061 const Target_arm<big_endian>* arm_target =
4062 Target_arm<big_endian>::default_target();
4063 if (is_weakly_undefined_without_plt)
4065 gold_assert(!parameters->options().relocatable());
4066 if (arm_target->may_use_thumb2_nop())
4068 elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4069 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4071 else
4073 elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4074 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4076 return This::STATUS_OKAY;
4079 int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4080 Arm_address branch_target = psymval->value(object, addend);
4082 // For BLX, bit 1 of target address comes from bit 1 of base address.
4083 bool may_use_blx = arm_target->may_use_blx();
4084 if (thumb_bit == 0 && may_use_blx)
4085 branch_target = utils::bit_select(branch_target, address, 0x2);
4087 int32_t branch_offset = branch_target - address;
4089 // We need a stub if the branch offset is too large or if we need
4090 // to switch mode.
4091 bool thumb2 = arm_target->using_thumb2();
4092 if (!parameters->options().relocatable()
4093 && ((!thumb2 && utils::has_overflow<23>(branch_offset))
4094 || (thumb2 && utils::has_overflow<25>(branch_offset))
4095 || ((thumb_bit == 0)
4096 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4097 || r_type == elfcpp::R_ARM_THM_JUMP24))))
4099 Arm_address unadjusted_branch_target = psymval->value(object, 0);
4101 Stub_type stub_type =
4102 Reloc_stub::stub_type_for_reloc(r_type, address,
4103 unadjusted_branch_target,
4104 (thumb_bit != 0));
4106 if (stub_type != arm_stub_none)
4108 Stub_table<big_endian>* stub_table =
4109 object->stub_table(relinfo->data_shndx);
4110 gold_assert(stub_table != NULL);
4112 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4113 Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4114 gold_assert(stub != NULL);
4115 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4116 branch_target = stub_table->address() + stub->offset() + addend;
4117 if (thumb_bit == 0 && may_use_blx)
4118 branch_target = utils::bit_select(branch_target, address, 0x2);
4119 branch_offset = branch_target - address;
4123 // At this point, if we still need to switch mode, the instruction
4124 // must either be a BLX or a BL that can be converted to a BLX.
4125 if (thumb_bit == 0)
4127 gold_assert(may_use_blx
4128 && (r_type == elfcpp::R_ARM_THM_CALL
4129 || r_type == elfcpp::R_ARM_THM_XPC22));
4130 // Make sure this is a BLX.
4131 lower_insn &= ~0x1000U;
4133 else
4135 // Make sure this is a BL.
4136 lower_insn |= 0x1000U;
4139 // For a BLX instruction, make sure that the relocation is rounded up
4140 // to a word boundary. This follows the semantics of the instruction
4141 // which specifies that bit 1 of the target address will come from bit
4142 // 1 of the base address.
4143 if ((lower_insn & 0x5000U) == 0x4000U)
4144 gold_assert((branch_offset & 3) == 0);
4146 // Put BRANCH_OFFSET back into the insn. Assumes two's complement.
4147 // We use the Thumb-2 encoding, which is safe even if dealing with
4148 // a Thumb-1 instruction by virtue of our overflow check above. */
4149 upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4150 lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4152 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4153 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4155 gold_assert(!utils::has_overflow<25>(branch_offset));
4157 return ((thumb2
4158 ? utils::has_overflow<25>(branch_offset)
4159 : utils::has_overflow<23>(branch_offset))
4160 ? This::STATUS_OVERFLOW
4161 : This::STATUS_OKAY);
4164 // Relocate THUMB-2 long conditional branches.
4165 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
4166 // undefined and we do not use PLT in this relocation. In such a case,
4167 // the branch is converted into an NOP.
4169 template<bool big_endian>
4170 typename Arm_relocate_functions<big_endian>::Status
4171 Arm_relocate_functions<big_endian>::thm_jump19(
4172 unsigned char* view,
4173 const Arm_relobj<big_endian>* object,
4174 const Symbol_value<32>* psymval,
4175 Arm_address address,
4176 Arm_address thumb_bit)
4178 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4179 Valtype* wv = reinterpret_cast<Valtype*>(view);
4180 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4181 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4182 int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4184 Arm_address branch_target = psymval->value(object, addend);
4185 int32_t branch_offset = branch_target - address;
4187 // ??? Should handle interworking? GCC might someday try to
4188 // use this for tail calls.
4189 // FIXME: We do support thumb entry to PLT yet.
4190 if (thumb_bit == 0)
4192 gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4193 return This::STATUS_BAD_RELOC;
4196 // Put RELOCATION back into the insn.
4197 upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4198 lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4200 // Put the relocated value back in the object file:
4201 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4202 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4204 return (utils::has_overflow<21>(branch_offset)
4205 ? This::STATUS_OVERFLOW
4206 : This::STATUS_OKAY);
4209 // Get the GOT section, creating it if necessary.
4211 template<bool big_endian>
4212 Arm_output_data_got<big_endian>*
4213 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4215 if (this->got_ == NULL)
4217 gold_assert(symtab != NULL && layout != NULL);
4219 this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4221 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4222 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4223 this->got_, ORDER_DATA, false);
4225 // The old GNU linker creates a .got.plt section. We just
4226 // create another set of data in the .got section. Note that we
4227 // always create a PLT if we create a GOT, although the PLT
4228 // might be empty.
4229 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4230 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4231 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4232 this->got_plt_, ORDER_DATA, false);
4234 // The first three entries are reserved.
4235 this->got_plt_->set_current_data_size(3 * 4);
4237 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4238 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4239 Symbol_table::PREDEFINED,
4240 this->got_plt_,
4241 0, 0, elfcpp::STT_OBJECT,
4242 elfcpp::STB_LOCAL,
4243 elfcpp::STV_HIDDEN, 0,
4244 false, false);
4246 return this->got_;
4249 // Get the dynamic reloc section, creating it if necessary.
4251 template<bool big_endian>
4252 typename Target_arm<big_endian>::Reloc_section*
4253 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4255 if (this->rel_dyn_ == NULL)
4257 gold_assert(layout != NULL);
4258 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4259 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4260 elfcpp::SHF_ALLOC, this->rel_dyn_,
4261 ORDER_DYNAMIC_RELOCS, false);
4263 return this->rel_dyn_;
4266 // Insn_template methods.
4268 // Return byte size of an instruction template.
4270 size_t
4271 Insn_template::size() const
4273 switch (this->type())
4275 case THUMB16_TYPE:
4276 case THUMB16_SPECIAL_TYPE:
4277 return 2;
4278 case ARM_TYPE:
4279 case THUMB32_TYPE:
4280 case DATA_TYPE:
4281 return 4;
4282 default:
4283 gold_unreachable();
4287 // Return alignment of an instruction template.
4289 unsigned
4290 Insn_template::alignment() const
4292 switch (this->type())
4294 case THUMB16_TYPE:
4295 case THUMB16_SPECIAL_TYPE:
4296 case THUMB32_TYPE:
4297 return 2;
4298 case ARM_TYPE:
4299 case DATA_TYPE:
4300 return 4;
4301 default:
4302 gold_unreachable();
4306 // Stub_template methods.
4308 Stub_template::Stub_template(
4309 Stub_type type, const Insn_template* insns,
4310 size_t insn_count)
4311 : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4312 entry_in_thumb_mode_(false), relocs_()
4314 off_t offset = 0;
4316 // Compute byte size and alignment of stub template.
4317 for (size_t i = 0; i < insn_count; i++)
4319 unsigned insn_alignment = insns[i].alignment();
4320 size_t insn_size = insns[i].size();
4321 gold_assert((offset & (insn_alignment - 1)) == 0);
4322 this->alignment_ = std::max(this->alignment_, insn_alignment);
4323 switch (insns[i].type())
4325 case Insn_template::THUMB16_TYPE:
4326 case Insn_template::THUMB16_SPECIAL_TYPE:
4327 if (i == 0)
4328 this->entry_in_thumb_mode_ = true;
4329 break;
4331 case Insn_template::THUMB32_TYPE:
4332 if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4333 this->relocs_.push_back(Reloc(i, offset));
4334 if (i == 0)
4335 this->entry_in_thumb_mode_ = true;
4336 break;
4338 case Insn_template::ARM_TYPE:
4339 // Handle cases where the target is encoded within the
4340 // instruction.
4341 if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4342 this->relocs_.push_back(Reloc(i, offset));
4343 break;
4345 case Insn_template::DATA_TYPE:
4346 // Entry point cannot be data.
4347 gold_assert(i != 0);
4348 this->relocs_.push_back(Reloc(i, offset));
4349 break;
4351 default:
4352 gold_unreachable();
4354 offset += insn_size;
4356 this->size_ = offset;
4359 // Stub methods.
4361 // Template to implement do_write for a specific target endianness.
4363 template<bool big_endian>
4364 void inline
4365 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4367 const Stub_template* stub_template = this->stub_template();
4368 const Insn_template* insns = stub_template->insns();
4370 // FIXME: We do not handle BE8 encoding yet.
4371 unsigned char* pov = view;
4372 for (size_t i = 0; i < stub_template->insn_count(); i++)
4374 switch (insns[i].type())
4376 case Insn_template::THUMB16_TYPE:
4377 elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4378 break;
4379 case Insn_template::THUMB16_SPECIAL_TYPE:
4380 elfcpp::Swap<16, big_endian>::writeval(
4381 pov,
4382 this->thumb16_special(i));
4383 break;
4384 case Insn_template::THUMB32_TYPE:
4386 uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4387 uint32_t lo = insns[i].data() & 0xffff;
4388 elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4389 elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4391 break;
4392 case Insn_template::ARM_TYPE:
4393 case Insn_template::DATA_TYPE:
4394 elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4395 break;
4396 default:
4397 gold_unreachable();
4399 pov += insns[i].size();
4401 gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4404 // Reloc_stub::Key methods.
4406 // Dump a Key as a string for debugging.
4408 std::string
4409 Reloc_stub::Key::name() const
4411 if (this->r_sym_ == invalid_index)
4413 // Global symbol key name
4414 // <stub-type>:<symbol name>:<addend>.
4415 const std::string sym_name = this->u_.symbol->name();
4416 // We need to print two hex number and two colons. So just add 100 bytes
4417 // to the symbol name size.
4418 size_t len = sym_name.size() + 100;
4419 char* buffer = new char[len];
4420 int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4421 sym_name.c_str(), this->addend_);
4422 gold_assert(c > 0 && c < static_cast<int>(len));
4423 delete[] buffer;
4424 return std::string(buffer);
4426 else
4428 // local symbol key name
4429 // <stub-type>:<object>:<r_sym>:<addend>.
4430 const size_t len = 200;
4431 char buffer[len];
4432 int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4433 this->u_.relobj, this->r_sym_, this->addend_);
4434 gold_assert(c > 0 && c < static_cast<int>(len));
4435 return std::string(buffer);
4439 // Reloc_stub methods.
4441 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4442 // LOCATION to DESTINATION.
4443 // This code is based on the arm_type_of_stub function in
4444 // bfd/elf32-arm.c. We have changed the interface a little to keep the Stub
4445 // class simple.
4447 Stub_type
4448 Reloc_stub::stub_type_for_reloc(
4449 unsigned int r_type,
4450 Arm_address location,
4451 Arm_address destination,
4452 bool target_is_thumb)
4454 Stub_type stub_type = arm_stub_none;
4456 // This is a bit ugly but we want to avoid using a templated class for
4457 // big and little endianities.
4458 bool may_use_blx;
4459 bool should_force_pic_veneer;
4460 bool thumb2;
4461 bool thumb_only;
4462 if (parameters->target().is_big_endian())
4464 const Target_arm<true>* big_endian_target =
4465 Target_arm<true>::default_target();
4466 may_use_blx = big_endian_target->may_use_blx();
4467 should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4468 thumb2 = big_endian_target->using_thumb2();
4469 thumb_only = big_endian_target->using_thumb_only();
4471 else
4473 const Target_arm<false>* little_endian_target =
4474 Target_arm<false>::default_target();
4475 may_use_blx = little_endian_target->may_use_blx();
4476 should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4477 thumb2 = little_endian_target->using_thumb2();
4478 thumb_only = little_endian_target->using_thumb_only();
4481 int64_t branch_offset;
4482 if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4484 // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4485 // base address (instruction address + 4).
4486 if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4487 destination = utils::bit_select(destination, location, 0x2);
4488 branch_offset = static_cast<int64_t>(destination) - location;
4490 // Handle cases where:
4491 // - this call goes too far (different Thumb/Thumb2 max
4492 // distance)
4493 // - it's a Thumb->Arm call and blx is not available, or it's a
4494 // Thumb->Arm branch (not bl). A stub is needed in this case.
4495 if ((!thumb2
4496 && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4497 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4498 || (thumb2
4499 && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4500 || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4501 || ((!target_is_thumb)
4502 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4503 || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4505 if (target_is_thumb)
4507 // Thumb to thumb.
4508 if (!thumb_only)
4510 stub_type = (parameters->options().shared()
4511 || should_force_pic_veneer)
4512 // PIC stubs.
4513 ? ((may_use_blx
4514 && (r_type == elfcpp::R_ARM_THM_CALL))
4515 // V5T and above. Stub starts with ARM code, so
4516 // we must be able to switch mode before
4517 // reaching it, which is only possible for 'bl'
4518 // (ie R_ARM_THM_CALL relocation).
4519 ? arm_stub_long_branch_any_thumb_pic
4520 // On V4T, use Thumb code only.
4521 : arm_stub_long_branch_v4t_thumb_thumb_pic)
4523 // non-PIC stubs.
4524 : ((may_use_blx
4525 && (r_type == elfcpp::R_ARM_THM_CALL))
4526 ? arm_stub_long_branch_any_any // V5T and above.
4527 : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4529 else
4531 stub_type = (parameters->options().shared()
4532 || should_force_pic_veneer)
4533 ? arm_stub_long_branch_thumb_only_pic // PIC stub.
4534 : arm_stub_long_branch_thumb_only; // non-PIC stub.
4537 else
4539 // Thumb to arm.
4541 // FIXME: We should check that the input section is from an
4542 // object that has interwork enabled.
4544 stub_type = (parameters->options().shared()
4545 || should_force_pic_veneer)
4546 // PIC stubs.
4547 ? ((may_use_blx
4548 && (r_type == elfcpp::R_ARM_THM_CALL))
4549 ? arm_stub_long_branch_any_arm_pic // V5T and above.
4550 : arm_stub_long_branch_v4t_thumb_arm_pic) // V4T.
4552 // non-PIC stubs.
4553 : ((may_use_blx
4554 && (r_type == elfcpp::R_ARM_THM_CALL))
4555 ? arm_stub_long_branch_any_any // V5T and above.
4556 : arm_stub_long_branch_v4t_thumb_arm); // V4T.
4558 // Handle v4t short branches.
4559 if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4560 && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4561 && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4562 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4566 else if (r_type == elfcpp::R_ARM_CALL
4567 || r_type == elfcpp::R_ARM_JUMP24
4568 || r_type == elfcpp::R_ARM_PLT32)
4570 branch_offset = static_cast<int64_t>(destination) - location;
4571 if (target_is_thumb)
4573 // Arm to thumb.
4575 // FIXME: We should check that the input section is from an
4576 // object that has interwork enabled.
4578 // We have an extra 2-bytes reach because of
4579 // the mode change (bit 24 (H) of BLX encoding).
4580 if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4581 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4582 || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4583 || (r_type == elfcpp::R_ARM_JUMP24)
4584 || (r_type == elfcpp::R_ARM_PLT32))
4586 stub_type = (parameters->options().shared()
4587 || should_force_pic_veneer)
4588 // PIC stubs.
4589 ? (may_use_blx
4590 ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4591 : arm_stub_long_branch_v4t_arm_thumb_pic) // V4T stub.
4593 // non-PIC stubs.
4594 : (may_use_blx
4595 ? arm_stub_long_branch_any_any // V5T and above.
4596 : arm_stub_long_branch_v4t_arm_thumb); // V4T.
4599 else
4601 // Arm to arm.
4602 if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4603 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4605 stub_type = (parameters->options().shared()
4606 || should_force_pic_veneer)
4607 ? arm_stub_long_branch_any_arm_pic // PIC stubs.
4608 : arm_stub_long_branch_any_any; /// non-PIC.
4613 return stub_type;
4616 // Cortex_a8_stub methods.
4618 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4619 // I is the position of the instruction template in the stub template.
4621 uint16_t
4622 Cortex_a8_stub::do_thumb16_special(size_t i)
4624 // The only use of this is to copy condition code from a conditional
4625 // branch being worked around to the corresponding conditional branch in
4626 // to the stub.
4627 gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4628 && i == 0);
4629 uint16_t data = this->stub_template()->insns()[i].data();
4630 gold_assert((data & 0xff00U) == 0xd000U);
4631 data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4632 return data;
4635 // Stub_factory methods.
4637 Stub_factory::Stub_factory()
4639 // The instruction template sequences are declared as static
4640 // objects and initialized first time the constructor runs.
4642 // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4643 // to reach the stub if necessary.
4644 static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4646 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4647 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4648 // dcd R_ARM_ABS32(X)
4651 // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4652 // available.
4653 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4655 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4656 Insn_template::arm_insn(0xe12fff1c), // bx ip
4657 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4658 // dcd R_ARM_ABS32(X)
4661 // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4662 static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4664 Insn_template::thumb16_insn(0xb401), // push {r0}
4665 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4666 Insn_template::thumb16_insn(0x4684), // mov ip, r0
4667 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4668 Insn_template::thumb16_insn(0x4760), // bx ip
4669 Insn_template::thumb16_insn(0xbf00), // nop
4670 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4671 // dcd R_ARM_ABS32(X)
4674 // V4T Thumb -> Thumb long branch stub. Using the stack is not
4675 // allowed.
4676 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4678 Insn_template::thumb16_insn(0x4778), // bx pc
4679 Insn_template::thumb16_insn(0x46c0), // nop
4680 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4681 Insn_template::arm_insn(0xe12fff1c), // bx ip
4682 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4683 // dcd R_ARM_ABS32(X)
4686 // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4687 // available.
4688 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4690 Insn_template::thumb16_insn(0x4778), // bx pc
4691 Insn_template::thumb16_insn(0x46c0), // nop
4692 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4693 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4694 // dcd R_ARM_ABS32(X)
4697 // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4698 // one, when the destination is close enough.
4699 static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4701 Insn_template::thumb16_insn(0x4778), // bx pc
4702 Insn_template::thumb16_insn(0x46c0), // nop
4703 Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8)
4706 // ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use
4707 // blx to reach the stub if necessary.
4708 static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4710 Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc]
4711 Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip
4712 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4713 // dcd R_ARM_REL32(X-4)
4716 // ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use
4717 // blx to reach the stub if necessary. We can not add into pc;
4718 // it is not guaranteed to mode switch (different in ARMv6 and
4719 // ARMv7).
4720 static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4722 Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4]
4723 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4724 Insn_template::arm_insn(0xe12fff1c), // bx ip
4725 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4726 // dcd R_ARM_REL32(X)
4729 // V4T ARM -> ARM long branch stub, PIC.
4730 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4732 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4733 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4734 Insn_template::arm_insn(0xe12fff1c), // bx ip
4735 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4736 // dcd R_ARM_REL32(X)
4739 // V4T Thumb -> ARM long branch stub, PIC.
4740 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4742 Insn_template::thumb16_insn(0x4778), // bx pc
4743 Insn_template::thumb16_insn(0x46c0), // nop
4744 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4745 Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc
4746 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4747 // dcd R_ARM_REL32(X)
4750 // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4751 // architectures.
4752 static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4754 Insn_template::thumb16_insn(0xb401), // push {r0}
4755 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4756 Insn_template::thumb16_insn(0x46fc), // mov ip, pc
4757 Insn_template::thumb16_insn(0x4484), // add ip, r0
4758 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4759 Insn_template::thumb16_insn(0x4760), // bx ip
4760 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4761 // dcd R_ARM_REL32(X)
4764 // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4765 // allowed.
4766 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4768 Insn_template::thumb16_insn(0x4778), // bx pc
4769 Insn_template::thumb16_insn(0x46c0), // nop
4770 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4771 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4772 Insn_template::arm_insn(0xe12fff1c), // bx ip
4773 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4774 // dcd R_ARM_REL32(X)
4777 // Cortex-A8 erratum-workaround stubs.
4779 // Stub used for conditional branches (which may be beyond +/-1MB away,
4780 // so we can't use a conditional branch to reach this stub).
4782 // original code:
4784 // b<cond> X
4785 // after:
4787 static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4789 Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true
4790 Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after
4791 Insn_template::thumb32_b_insn(0xf000b800, -4) // true:
4792 // b.w X
4795 // Stub used for b.w and bl.w instructions.
4797 static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4799 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4802 static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4804 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4807 // Stub used for Thumb-2 blx.w instructions. We modified the original blx.w
4808 // instruction (which switches to ARM mode) to point to this stub. Jump to
4809 // the real destination using an ARM-mode branch.
4810 static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4812 Insn_template::arm_rel_insn(0xea000000, -8) // b dest
4815 // Stub used to provide an interworking for R_ARM_V4BX relocation
4816 // (bx r[n] instruction).
4817 static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4819 Insn_template::arm_insn(0xe3100001), // tst r<n>, #1
4820 Insn_template::arm_insn(0x01a0f000), // moveq pc, r<n>
4821 Insn_template::arm_insn(0xe12fff10) // bx r<n>
4824 // Fill in the stub template look-up table. Stub templates are constructed
4825 // per instance of Stub_factory for fast look-up without locking
4826 // in a thread-enabled environment.
4828 this->stub_templates_[arm_stub_none] =
4829 new Stub_template(arm_stub_none, NULL, 0);
4831 #define DEF_STUB(x) \
4832 do \
4834 size_t array_size \
4835 = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4836 Stub_type type = arm_stub_##x; \
4837 this->stub_templates_[type] = \
4838 new Stub_template(type, elf32_arm_stub_##x, array_size); \
4840 while (0);
4842 DEF_STUBS
4843 #undef DEF_STUB
4846 // Stub_table methods.
4848 // Remove all Cortex-A8 stub.
4850 template<bool big_endian>
4851 void
4852 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4854 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4855 p != this->cortex_a8_stubs_.end();
4856 ++p)
4857 delete p->second;
4858 this->cortex_a8_stubs_.clear();
4861 // Relocate one stub. This is a helper for Stub_table::relocate_stubs().
4863 template<bool big_endian>
4864 void
4865 Stub_table<big_endian>::relocate_stub(
4866 Stub* stub,
4867 const Relocate_info<32, big_endian>* relinfo,
4868 Target_arm<big_endian>* arm_target,
4869 Output_section* output_section,
4870 unsigned char* view,
4871 Arm_address address,
4872 section_size_type view_size)
4874 const Stub_template* stub_template = stub->stub_template();
4875 if (stub_template->reloc_count() != 0)
4877 // Adjust view to cover the stub only.
4878 section_size_type offset = stub->offset();
4879 section_size_type stub_size = stub_template->size();
4880 gold_assert(offset + stub_size <= view_size);
4882 arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4883 address + offset, stub_size);
4887 // Relocate all stubs in this stub table.
4889 template<bool big_endian>
4890 void
4891 Stub_table<big_endian>::relocate_stubs(
4892 const Relocate_info<32, big_endian>* relinfo,
4893 Target_arm<big_endian>* arm_target,
4894 Output_section* output_section,
4895 unsigned char* view,
4896 Arm_address address,
4897 section_size_type view_size)
4899 // If we are passed a view bigger than the stub table's. we need to
4900 // adjust the view.
4901 gold_assert(address == this->address()
4902 && (view_size
4903 == static_cast<section_size_type>(this->data_size())));
4905 // Relocate all relocation stubs.
4906 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4907 p != this->reloc_stubs_.end();
4908 ++p)
4909 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4910 address, view_size);
4912 // Relocate all Cortex-A8 stubs.
4913 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4914 p != this->cortex_a8_stubs_.end();
4915 ++p)
4916 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4917 address, view_size);
4919 // Relocate all ARM V4BX stubs.
4920 for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4921 p != this->arm_v4bx_stubs_.end();
4922 ++p)
4924 if (*p != NULL)
4925 this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4926 address, view_size);
4930 // Write out the stubs to file.
4932 template<bool big_endian>
4933 void
4934 Stub_table<big_endian>::do_write(Output_file* of)
4936 off_t offset = this->offset();
4937 const section_size_type oview_size =
4938 convert_to_section_size_type(this->data_size());
4939 unsigned char* const oview = of->get_output_view(offset, oview_size);
4941 // Write relocation stubs.
4942 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4943 p != this->reloc_stubs_.end();
4944 ++p)
4946 Reloc_stub* stub = p->second;
4947 Arm_address address = this->address() + stub->offset();
4948 gold_assert(address
4949 == align_address(address,
4950 stub->stub_template()->alignment()));
4951 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4952 big_endian);
4955 // Write Cortex-A8 stubs.
4956 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4957 p != this->cortex_a8_stubs_.end();
4958 ++p)
4960 Cortex_a8_stub* stub = p->second;
4961 Arm_address address = this->address() + stub->offset();
4962 gold_assert(address
4963 == align_address(address,
4964 stub->stub_template()->alignment()));
4965 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4966 big_endian);
4969 // Write ARM V4BX relocation stubs.
4970 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4971 p != this->arm_v4bx_stubs_.end();
4972 ++p)
4974 if (*p == NULL)
4975 continue;
4977 Arm_address address = this->address() + (*p)->offset();
4978 gold_assert(address
4979 == align_address(address,
4980 (*p)->stub_template()->alignment()));
4981 (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4982 big_endian);
4985 of->write_output_view(this->offset(), oview_size, oview);
4988 // Update the data size and address alignment of the stub table at the end
4989 // of a relaxation pass. Return true if either the data size or the
4990 // alignment changed in this relaxation pass.
4992 template<bool big_endian>
4993 bool
4994 Stub_table<big_endian>::update_data_size_and_addralign()
4996 // Go over all stubs in table to compute data size and address alignment.
4997 off_t size = this->reloc_stubs_size_;
4998 unsigned addralign = this->reloc_stubs_addralign_;
5000 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5001 p != this->cortex_a8_stubs_.end();
5002 ++p)
5004 const Stub_template* stub_template = p->second->stub_template();
5005 addralign = std::max(addralign, stub_template->alignment());
5006 size = (align_address(size, stub_template->alignment())
5007 + stub_template->size());
5010 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5011 p != this->arm_v4bx_stubs_.end();
5012 ++p)
5014 if (*p == NULL)
5015 continue;
5017 const Stub_template* stub_template = (*p)->stub_template();
5018 addralign = std::max(addralign, stub_template->alignment());
5019 size = (align_address(size, stub_template->alignment())
5020 + stub_template->size());
5023 // Check if either data size or alignment changed in this pass.
5024 // Update prev_data_size_ and prev_addralign_. These will be used
5025 // as the current data size and address alignment for the next pass.
5026 bool changed = size != this->prev_data_size_;
5027 this->prev_data_size_ = size;
5029 if (addralign != this->prev_addralign_)
5030 changed = true;
5031 this->prev_addralign_ = addralign;
5033 return changed;
5036 // Finalize the stubs. This sets the offsets of the stubs within the stub
5037 // table. It also marks all input sections needing Cortex-A8 workaround.
5039 template<bool big_endian>
5040 void
5041 Stub_table<big_endian>::finalize_stubs()
5043 off_t off = this->reloc_stubs_size_;
5044 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5045 p != this->cortex_a8_stubs_.end();
5046 ++p)
5048 Cortex_a8_stub* stub = p->second;
5049 const Stub_template* stub_template = stub->stub_template();
5050 uint64_t stub_addralign = stub_template->alignment();
5051 off = align_address(off, stub_addralign);
5052 stub->set_offset(off);
5053 off += stub_template->size();
5055 // Mark input section so that we can determine later if a code section
5056 // needs the Cortex-A8 workaround quickly.
5057 Arm_relobj<big_endian>* arm_relobj =
5058 Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5059 arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5062 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5063 p != this->arm_v4bx_stubs_.end();
5064 ++p)
5066 if (*p == NULL)
5067 continue;
5069 const Stub_template* stub_template = (*p)->stub_template();
5070 uint64_t stub_addralign = stub_template->alignment();
5071 off = align_address(off, stub_addralign);
5072 (*p)->set_offset(off);
5073 off += stub_template->size();
5076 gold_assert(off <= this->prev_data_size_);
5079 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5080 // and VIEW_ADDRESS + VIEW_SIZE - 1. VIEW points to the mapped address
5081 // of the address range seen by the linker.
5083 template<bool big_endian>
5084 void
5085 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5086 Target_arm<big_endian>* arm_target,
5087 unsigned char* view,
5088 Arm_address view_address,
5089 section_size_type view_size)
5091 // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5092 for (Cortex_a8_stub_list::const_iterator p =
5093 this->cortex_a8_stubs_.lower_bound(view_address);
5094 ((p != this->cortex_a8_stubs_.end())
5095 && (p->first < (view_address + view_size)));
5096 ++p)
5098 // We do not store the THUMB bit in the LSB of either the branch address
5099 // or the stub offset. There is no need to strip the LSB.
5100 Arm_address branch_address = p->first;
5101 const Cortex_a8_stub* stub = p->second;
5102 Arm_address stub_address = this->address() + stub->offset();
5104 // Offset of the branch instruction relative to this view.
5105 section_size_type offset =
5106 convert_to_section_size_type(branch_address - view_address);
5107 gold_assert((offset + 4) <= view_size);
5109 arm_target->apply_cortex_a8_workaround(stub, stub_address,
5110 view + offset, branch_address);
5114 // Arm_input_section methods.
5116 // Initialize an Arm_input_section.
5118 template<bool big_endian>
5119 void
5120 Arm_input_section<big_endian>::init()
5122 Relobj* relobj = this->relobj();
5123 unsigned int shndx = this->shndx();
5125 // We have to cache original size, alignment and contents to avoid locking
5126 // the original file.
5127 this->original_addralign_ =
5128 convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5130 // This is not efficient but we expect only a small number of relaxed
5131 // input sections for stubs.
5132 section_size_type section_size;
5133 const unsigned char* section_contents =
5134 relobj->section_contents(shndx, &section_size, false);
5135 this->original_size_ =
5136 convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5138 gold_assert(this->original_contents_ == NULL);
5139 this->original_contents_ = new unsigned char[section_size];
5140 memcpy(this->original_contents_, section_contents, section_size);
5142 // We want to make this look like the original input section after
5143 // output sections are finalized.
5144 Output_section* os = relobj->output_section(shndx);
5145 off_t offset = relobj->output_section_offset(shndx);
5146 gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5147 this->set_address(os->address() + offset);
5148 this->set_file_offset(os->offset() + offset);
5150 this->set_current_data_size(this->original_size_);
5151 this->finalize_data_size();
5154 template<bool big_endian>
5155 void
5156 Arm_input_section<big_endian>::do_write(Output_file* of)
5158 // We have to write out the original section content.
5159 gold_assert(this->original_contents_ != NULL);
5160 of->write(this->offset(), this->original_contents_,
5161 this->original_size_);
5163 // If this owns a stub table and it is not empty, write it.
5164 if (this->is_stub_table_owner() && !this->stub_table_->empty())
5165 this->stub_table_->write(of);
5168 // Finalize data size.
5170 template<bool big_endian>
5171 void
5172 Arm_input_section<big_endian>::set_final_data_size()
5174 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5176 if (this->is_stub_table_owner())
5178 this->stub_table_->finalize_data_size();
5179 off = align_address(off, this->stub_table_->addralign());
5180 off += this->stub_table_->data_size();
5182 this->set_data_size(off);
5185 // Reset address and file offset.
5187 template<bool big_endian>
5188 void
5189 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5191 // Size of the original input section contents.
5192 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5194 // If this is a stub table owner, account for the stub table size.
5195 if (this->is_stub_table_owner())
5197 Stub_table<big_endian>* stub_table = this->stub_table_;
5199 // Reset the stub table's address and file offset. The
5200 // current data size for child will be updated after that.
5201 stub_table_->reset_address_and_file_offset();
5202 off = align_address(off, stub_table_->addralign());
5203 off += stub_table->current_data_size();
5206 this->set_current_data_size(off);
5209 // Arm_exidx_cantunwind methods.
5211 // Write this to Output file OF for a fixed endianness.
5213 template<bool big_endian>
5214 void
5215 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5217 off_t offset = this->offset();
5218 const section_size_type oview_size = 8;
5219 unsigned char* const oview = of->get_output_view(offset, oview_size);
5221 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5222 Valtype* wv = reinterpret_cast<Valtype*>(oview);
5224 Output_section* os = this->relobj_->output_section(this->shndx_);
5225 gold_assert(os != NULL);
5227 Arm_relobj<big_endian>* arm_relobj =
5228 Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5229 Arm_address output_offset =
5230 arm_relobj->get_output_section_offset(this->shndx_);
5231 Arm_address section_start;
5232 section_size_type section_size;
5234 // Find out the end of the text section referred by this.
5235 if (output_offset != Arm_relobj<big_endian>::invalid_address)
5237 section_start = os->address() + output_offset;
5238 const Arm_exidx_input_section* exidx_input_section =
5239 arm_relobj->exidx_input_section_by_link(this->shndx_);
5240 gold_assert(exidx_input_section != NULL);
5241 section_size =
5242 convert_to_section_size_type(exidx_input_section->text_size());
5244 else
5246 // Currently this only happens for a relaxed section.
5247 const Output_relaxed_input_section* poris =
5248 os->find_relaxed_input_section(this->relobj_, this->shndx_);
5249 gold_assert(poris != NULL);
5250 section_start = poris->address();
5251 section_size = convert_to_section_size_type(poris->data_size());
5254 // We always append this to the end of an EXIDX section.
5255 Arm_address output_address = section_start + section_size;
5257 // Write out the entry. The first word either points to the beginning
5258 // or after the end of a text section. The second word is the special
5259 // EXIDX_CANTUNWIND value.
5260 uint32_t prel31_offset = output_address - this->address();
5261 if (utils::has_overflow<31>(offset))
5262 gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5263 elfcpp::Swap<32, big_endian>::writeval(wv, prel31_offset & 0x7fffffffU);
5264 elfcpp::Swap<32, big_endian>::writeval(wv + 1, elfcpp::EXIDX_CANTUNWIND);
5266 of->write_output_view(this->offset(), oview_size, oview);
5269 // Arm_exidx_merged_section methods.
5271 // Constructor for Arm_exidx_merged_section.
5272 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5273 // SECTION_OFFSET_MAP points to a section offset map describing how
5274 // parts of the input section are mapped to output. DELETED_BYTES is
5275 // the number of bytes deleted from the EXIDX input section.
5277 Arm_exidx_merged_section::Arm_exidx_merged_section(
5278 const Arm_exidx_input_section& exidx_input_section,
5279 const Arm_exidx_section_offset_map& section_offset_map,
5280 uint32_t deleted_bytes)
5281 : Output_relaxed_input_section(exidx_input_section.relobj(),
5282 exidx_input_section.shndx(),
5283 exidx_input_section.addralign()),
5284 exidx_input_section_(exidx_input_section),
5285 section_offset_map_(section_offset_map)
5287 // If we retain or discard the whole EXIDX input section, we would
5288 // not be here.
5289 gold_assert(deleted_bytes != 0
5290 && deleted_bytes != this->exidx_input_section_.size());
5292 // Fix size here so that we do not need to implement set_final_data_size.
5293 uint32_t size = exidx_input_section.size() - deleted_bytes;
5294 this->set_data_size(size);
5295 this->fix_data_size();
5297 // Allocate buffer for section contents and build contents.
5298 this->section_contents_ = new unsigned char[size];
5301 // Build the contents of a merged EXIDX output section.
5303 void
5304 Arm_exidx_merged_section::build_contents(
5305 const unsigned char* original_contents,
5306 section_size_type original_size)
5308 // Go over spans of input offsets and write only those that are not
5309 // discarded.
5310 section_offset_type in_start = 0;
5311 section_offset_type out_start = 0;
5312 section_offset_type in_max =
5313 convert_types<section_offset_type>(original_size);
5314 section_offset_type out_max =
5315 convert_types<section_offset_type>(this->data_size());
5316 for (Arm_exidx_section_offset_map::const_iterator p =
5317 this->section_offset_map_.begin();
5318 p != this->section_offset_map_.end();
5319 ++p)
5321 section_offset_type in_end = p->first;
5322 gold_assert(in_end >= in_start);
5323 section_offset_type out_end = p->second;
5324 size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5325 if (out_end != -1)
5327 size_t out_chunk_size =
5328 convert_types<size_t>(out_end - out_start + 1);
5330 gold_assert(out_chunk_size == in_chunk_size
5331 && in_end < in_max && out_end < out_max);
5333 memcpy(this->section_contents_ + out_start,
5334 original_contents + in_start,
5335 out_chunk_size);
5336 out_start += out_chunk_size;
5338 in_start += in_chunk_size;
5342 // Given an input OBJECT, an input section index SHNDX within that
5343 // object, and an OFFSET relative to the start of that input
5344 // section, return whether or not the corresponding offset within
5345 // the output section is known. If this function returns true, it
5346 // sets *POUTPUT to the output offset. The value -1 indicates that
5347 // this input offset is being discarded.
5349 bool
5350 Arm_exidx_merged_section::do_output_offset(
5351 const Relobj* relobj,
5352 unsigned int shndx,
5353 section_offset_type offset,
5354 section_offset_type* poutput) const
5356 // We only handle offsets for the original EXIDX input section.
5357 if (relobj != this->exidx_input_section_.relobj()
5358 || shndx != this->exidx_input_section_.shndx())
5359 return false;
5361 section_offset_type section_size =
5362 convert_types<section_offset_type>(this->exidx_input_section_.size());
5363 if (offset < 0 || offset >= section_size)
5364 // Input offset is out of valid range.
5365 *poutput = -1;
5366 else
5368 // We need to look up the section offset map to determine the output
5369 // offset. Find the reference point in map that is first offset
5370 // bigger than or equal to this offset.
5371 Arm_exidx_section_offset_map::const_iterator p =
5372 this->section_offset_map_.lower_bound(offset);
5374 // The section offset maps are build such that this should not happen if
5375 // input offset is in the valid range.
5376 gold_assert(p != this->section_offset_map_.end());
5378 // We need to check if this is dropped.
5379 section_offset_type ref = p->first;
5380 section_offset_type mapped_ref = p->second;
5382 if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5383 // Offset is present in output.
5384 *poutput = mapped_ref + (offset - ref);
5385 else
5386 // Offset is discarded owing to EXIDX entry merging.
5387 *poutput = -1;
5390 return true;
5393 // Write this to output file OF.
5395 void
5396 Arm_exidx_merged_section::do_write(Output_file* of)
5398 off_t offset = this->offset();
5399 const section_size_type oview_size = this->data_size();
5400 unsigned char* const oview = of->get_output_view(offset, oview_size);
5402 Output_section* os = this->relobj()->output_section(this->shndx());
5403 gold_assert(os != NULL);
5405 memcpy(oview, this->section_contents_, oview_size);
5406 of->write_output_view(this->offset(), oview_size, oview);
5409 // Arm_exidx_fixup methods.
5411 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5412 // is not an EXIDX_CANTUNWIND entry already. The new EXIDX_CANTUNWIND entry
5413 // points to the end of the last seen EXIDX section.
5415 void
5416 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5418 if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5419 && this->last_input_section_ != NULL)
5421 Relobj* relobj = this->last_input_section_->relobj();
5422 unsigned int text_shndx = this->last_input_section_->link();
5423 Arm_exidx_cantunwind* cantunwind =
5424 new Arm_exidx_cantunwind(relobj, text_shndx);
5425 this->exidx_output_section_->add_output_section_data(cantunwind);
5426 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5430 // Process an EXIDX section entry in input. Return whether this entry
5431 // can be deleted in the output. SECOND_WORD in the second word of the
5432 // EXIDX entry.
5434 bool
5435 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5437 bool delete_entry;
5438 if (second_word == elfcpp::EXIDX_CANTUNWIND)
5440 // Merge if previous entry is also an EXIDX_CANTUNWIND.
5441 delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5442 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5444 else if ((second_word & 0x80000000) != 0)
5446 // Inlined unwinding data. Merge if equal to previous.
5447 delete_entry = (merge_exidx_entries_
5448 && this->last_unwind_type_ == UT_INLINED_ENTRY
5449 && this->last_inlined_entry_ == second_word);
5450 this->last_unwind_type_ = UT_INLINED_ENTRY;
5451 this->last_inlined_entry_ = second_word;
5453 else
5455 // Normal table entry. In theory we could merge these too,
5456 // but duplicate entries are likely to be much less common.
5457 delete_entry = false;
5458 this->last_unwind_type_ = UT_NORMAL_ENTRY;
5460 return delete_entry;
5463 // Update the current section offset map during EXIDX section fix-up.
5464 // If there is no map, create one. INPUT_OFFSET is the offset of a
5465 // reference point, DELETED_BYTES is the number of deleted by in the
5466 // section so far. If DELETE_ENTRY is true, the reference point and
5467 // all offsets after the previous reference point are discarded.
5469 void
5470 Arm_exidx_fixup::update_offset_map(
5471 section_offset_type input_offset,
5472 section_size_type deleted_bytes,
5473 bool delete_entry)
5475 if (this->section_offset_map_ == NULL)
5476 this->section_offset_map_ = new Arm_exidx_section_offset_map();
5477 section_offset_type output_offset;
5478 if (delete_entry)
5479 output_offset = Arm_exidx_input_section::invalid_offset;
5480 else
5481 output_offset = input_offset - deleted_bytes;
5482 (*this->section_offset_map_)[input_offset] = output_offset;
5485 // Process EXIDX_INPUT_SECTION for EXIDX entry merging. Return the number of
5486 // bytes deleted. SECTION_CONTENTS points to the contents of the EXIDX
5487 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5488 // If some entries are merged, also store a pointer to a newly created
5489 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP. The caller
5490 // owns the map and is responsible for releasing it after use.
5492 template<bool big_endian>
5493 uint32_t
5494 Arm_exidx_fixup::process_exidx_section(
5495 const Arm_exidx_input_section* exidx_input_section,
5496 const unsigned char* section_contents,
5497 section_size_type section_size,
5498 Arm_exidx_section_offset_map** psection_offset_map)
5500 Relobj* relobj = exidx_input_section->relobj();
5501 unsigned shndx = exidx_input_section->shndx();
5503 if ((section_size % 8) != 0)
5505 // Something is wrong with this section. Better not touch it.
5506 gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5507 relobj->name().c_str(), shndx);
5508 this->last_input_section_ = exidx_input_section;
5509 this->last_unwind_type_ = UT_NONE;
5510 return 0;
5513 uint32_t deleted_bytes = 0;
5514 bool prev_delete_entry = false;
5515 gold_assert(this->section_offset_map_ == NULL);
5517 for (section_size_type i = 0; i < section_size; i += 8)
5519 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5520 const Valtype* wv =
5521 reinterpret_cast<const Valtype*>(section_contents + i + 4);
5522 uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5524 bool delete_entry = this->process_exidx_entry(second_word);
5526 // Entry deletion causes changes in output offsets. We use a std::map
5527 // to record these. And entry (x, y) means input offset x
5528 // is mapped to output offset y. If y is invalid_offset, then x is
5529 // dropped in the output. Because of the way std::map::lower_bound
5530 // works, we record the last offset in a region w.r.t to keeping or
5531 // dropping. If there is no entry (x0, y0) for an input offset x0,
5532 // the output offset y0 of it is determined by the output offset y1 of
5533 // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5534 // in the map. If y1 is not -1, then y0 = y1 + x0 - x1. Otherwise, y1
5535 // y0 is also -1.
5536 if (delete_entry != prev_delete_entry && i != 0)
5537 this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5539 // Update total deleted bytes for this entry.
5540 if (delete_entry)
5541 deleted_bytes += 8;
5543 prev_delete_entry = delete_entry;
5546 // If section offset map is not NULL, make an entry for the end of
5547 // section.
5548 if (this->section_offset_map_ != NULL)
5549 update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5551 *psection_offset_map = this->section_offset_map_;
5552 this->section_offset_map_ = NULL;
5553 this->last_input_section_ = exidx_input_section;
5555 // Set the first output text section so that we can link the EXIDX output
5556 // section to it. Ignore any EXIDX input section that is completely merged.
5557 if (this->first_output_text_section_ == NULL
5558 && deleted_bytes != section_size)
5560 unsigned int link = exidx_input_section->link();
5561 Output_section* os = relobj->output_section(link);
5562 gold_assert(os != NULL);
5563 this->first_output_text_section_ = os;
5566 return deleted_bytes;
5569 // Arm_output_section methods.
5571 // Create a stub group for input sections from BEGIN to END. OWNER
5572 // points to the input section to be the owner a new stub table.
5574 template<bool big_endian>
5575 void
5576 Arm_output_section<big_endian>::create_stub_group(
5577 Input_section_list::const_iterator begin,
5578 Input_section_list::const_iterator end,
5579 Input_section_list::const_iterator owner,
5580 Target_arm<big_endian>* target,
5581 std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5582 const Task* task)
5584 // We use a different kind of relaxed section in an EXIDX section.
5585 // The static casting from Output_relaxed_input_section to
5586 // Arm_input_section is invalid in an EXIDX section. We are okay
5587 // because we should not be calling this for an EXIDX section.
5588 gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5590 // Currently we convert ordinary input sections into relaxed sections only
5591 // at this point but we may want to support creating relaxed input section
5592 // very early. So we check here to see if owner is already a relaxed
5593 // section.
5595 Arm_input_section<big_endian>* arm_input_section;
5596 if (owner->is_relaxed_input_section())
5598 arm_input_section =
5599 Arm_input_section<big_endian>::as_arm_input_section(
5600 owner->relaxed_input_section());
5602 else
5604 gold_assert(owner->is_input_section());
5605 // Create a new relaxed input section. We need to lock the original
5606 // file.
5607 Task_lock_obj<Object> tl(task, owner->relobj());
5608 arm_input_section =
5609 target->new_arm_input_section(owner->relobj(), owner->shndx());
5610 new_relaxed_sections->push_back(arm_input_section);
5613 // Create a stub table.
5614 Stub_table<big_endian>* stub_table =
5615 target->new_stub_table(arm_input_section);
5617 arm_input_section->set_stub_table(stub_table);
5619 Input_section_list::const_iterator p = begin;
5620 Input_section_list::const_iterator prev_p;
5622 // Look for input sections or relaxed input sections in [begin ... end].
5625 if (p->is_input_section() || p->is_relaxed_input_section())
5627 // The stub table information for input sections live
5628 // in their objects.
5629 Arm_relobj<big_endian>* arm_relobj =
5630 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5631 arm_relobj->set_stub_table(p->shndx(), stub_table);
5633 prev_p = p++;
5635 while (prev_p != end);
5638 // Group input sections for stub generation. GROUP_SIZE is roughly the limit
5639 // of stub groups. We grow a stub group by adding input section until the
5640 // size is just below GROUP_SIZE. The last input section will be converted
5641 // into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5642 // input section after the stub table, effectively double the group size.
5644 // This is similar to the group_sections() function in elf32-arm.c but is
5645 // implemented differently.
5647 template<bool big_endian>
5648 void
5649 Arm_output_section<big_endian>::group_sections(
5650 section_size_type group_size,
5651 bool stubs_always_after_branch,
5652 Target_arm<big_endian>* target,
5653 const Task* task)
5655 // We only care about sections containing code.
5656 if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
5657 return;
5659 // States for grouping.
5660 typedef enum
5662 // No group is being built.
5663 NO_GROUP,
5664 // A group is being built but the stub table is not found yet.
5665 // We keep group a stub group until the size is just under GROUP_SIZE.
5666 // The last input section in the group will be used as the stub table.
5667 FINDING_STUB_SECTION,
5668 // A group is being built and we have already found a stub table.
5669 // We enter this state to grow a stub group by adding input section
5670 // after the stub table. This effectively doubles the group size.
5671 HAS_STUB_SECTION
5672 } State;
5674 // Any newly created relaxed sections are stored here.
5675 std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5677 State state = NO_GROUP;
5678 section_size_type off = 0;
5679 section_size_type group_begin_offset = 0;
5680 section_size_type group_end_offset = 0;
5681 section_size_type stub_table_end_offset = 0;
5682 Input_section_list::const_iterator group_begin =
5683 this->input_sections().end();
5684 Input_section_list::const_iterator stub_table =
5685 this->input_sections().end();
5686 Input_section_list::const_iterator group_end = this->input_sections().end();
5687 for (Input_section_list::const_iterator p = this->input_sections().begin();
5688 p != this->input_sections().end();
5689 ++p)
5691 section_size_type section_begin_offset =
5692 align_address(off, p->addralign());
5693 section_size_type section_end_offset =
5694 section_begin_offset + p->data_size();
5696 // Check to see if we should group the previously seen sections.
5697 switch (state)
5699 case NO_GROUP:
5700 break;
5702 case FINDING_STUB_SECTION:
5703 // Adding this section makes the group larger than GROUP_SIZE.
5704 if (section_end_offset - group_begin_offset >= group_size)
5706 if (stubs_always_after_branch)
5708 gold_assert(group_end != this->input_sections().end());
5709 this->create_stub_group(group_begin, group_end, group_end,
5710 target, &new_relaxed_sections,
5711 task);
5712 state = NO_GROUP;
5714 else
5716 // But wait, there's more! Input sections up to
5717 // stub_group_size bytes after the stub table can be
5718 // handled by it too.
5719 state = HAS_STUB_SECTION;
5720 stub_table = group_end;
5721 stub_table_end_offset = group_end_offset;
5724 break;
5726 case HAS_STUB_SECTION:
5727 // Adding this section makes the post stub-section group larger
5728 // than GROUP_SIZE.
5729 if (section_end_offset - stub_table_end_offset >= group_size)
5731 gold_assert(group_end != this->input_sections().end());
5732 this->create_stub_group(group_begin, group_end, stub_table,
5733 target, &new_relaxed_sections, task);
5734 state = NO_GROUP;
5736 break;
5738 default:
5739 gold_unreachable();
5742 // If we see an input section and currently there is no group, start
5743 // a new one. Skip any empty sections. We look at the data size
5744 // instead of calling p->relobj()->section_size() to avoid locking.
5745 if ((p->is_input_section() || p->is_relaxed_input_section())
5746 && (p->data_size() != 0))
5748 if (state == NO_GROUP)
5750 state = FINDING_STUB_SECTION;
5751 group_begin = p;
5752 group_begin_offset = section_begin_offset;
5755 // Keep track of the last input section seen.
5756 group_end = p;
5757 group_end_offset = section_end_offset;
5760 off = section_end_offset;
5763 // Create a stub group for any ungrouped sections.
5764 if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5766 gold_assert(group_end != this->input_sections().end());
5767 this->create_stub_group(group_begin, group_end,
5768 (state == FINDING_STUB_SECTION
5769 ? group_end
5770 : stub_table),
5771 target, &new_relaxed_sections, task);
5774 // Convert input section into relaxed input section in a batch.
5775 if (!new_relaxed_sections.empty())
5776 this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5778 // Update the section offsets
5779 for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5781 Arm_relobj<big_endian>* arm_relobj =
5782 Arm_relobj<big_endian>::as_arm_relobj(
5783 new_relaxed_sections[i]->relobj());
5784 unsigned int shndx = new_relaxed_sections[i]->shndx();
5785 // Tell Arm_relobj that this input section is converted.
5786 arm_relobj->convert_input_section_to_relaxed_section(shndx);
5790 // Append non empty text sections in this to LIST in ascending
5791 // order of their position in this.
5793 template<bool big_endian>
5794 void
5795 Arm_output_section<big_endian>::append_text_sections_to_list(
5796 Text_section_list* list)
5798 gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5800 for (Input_section_list::const_iterator p = this->input_sections().begin();
5801 p != this->input_sections().end();
5802 ++p)
5804 // We only care about plain or relaxed input sections. We also
5805 // ignore any merged sections.
5806 if (p->is_input_section() || p->is_relaxed_input_section())
5807 list->push_back(Text_section_list::value_type(p->relobj(),
5808 p->shndx()));
5812 template<bool big_endian>
5813 void
5814 Arm_output_section<big_endian>::fix_exidx_coverage(
5815 Layout* layout,
5816 const Text_section_list& sorted_text_sections,
5817 Symbol_table* symtab,
5818 bool merge_exidx_entries,
5819 const Task* task)
5821 // We should only do this for the EXIDX output section.
5822 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5824 // We don't want the relaxation loop to undo these changes, so we discard
5825 // the current saved states and take another one after the fix-up.
5826 this->discard_states();
5828 // Remove all input sections.
5829 uint64_t address = this->address();
5830 typedef std::list<Output_section::Input_section> Input_section_list;
5831 Input_section_list input_sections;
5832 this->reset_address_and_file_offset();
5833 this->get_input_sections(address, std::string(""), &input_sections);
5835 if (!this->input_sections().empty())
5836 gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5838 // Go through all the known input sections and record them.
5839 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5840 typedef Unordered_map<Section_id, const Output_section::Input_section*,
5841 Section_id_hash> Text_to_exidx_map;
5842 Text_to_exidx_map text_to_exidx_map;
5843 for (Input_section_list::const_iterator p = input_sections.begin();
5844 p != input_sections.end();
5845 ++p)
5847 // This should never happen. At this point, we should only see
5848 // plain EXIDX input sections.
5849 gold_assert(!p->is_relaxed_input_section());
5850 text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5853 Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5855 // Go over the sorted text sections.
5856 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5857 Section_id_set processed_input_sections;
5858 for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5859 p != sorted_text_sections.end();
5860 ++p)
5862 Relobj* relobj = p->first;
5863 unsigned int shndx = p->second;
5865 Arm_relobj<big_endian>* arm_relobj =
5866 Arm_relobj<big_endian>::as_arm_relobj(relobj);
5867 const Arm_exidx_input_section* exidx_input_section =
5868 arm_relobj->exidx_input_section_by_link(shndx);
5870 // If this text section has no EXIDX section or if the EXIDX section
5871 // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5872 // of the last seen EXIDX section.
5873 if (exidx_input_section == NULL || exidx_input_section->has_errors())
5875 exidx_fixup.add_exidx_cantunwind_as_needed();
5876 continue;
5879 Relobj* exidx_relobj = exidx_input_section->relobj();
5880 unsigned int exidx_shndx = exidx_input_section->shndx();
5881 Section_id sid(exidx_relobj, exidx_shndx);
5882 Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5883 if (iter == text_to_exidx_map.end())
5885 // This is odd. We have not seen this EXIDX input section before.
5886 // We cannot do fix-up. If we saw a SECTIONS clause in a script,
5887 // issue a warning instead. We assume the user knows what he
5888 // or she is doing. Otherwise, this is an error.
5889 if (layout->script_options()->saw_sections_clause())
5890 gold_warning(_("unwinding may not work because EXIDX input section"
5891 " %u of %s is not in EXIDX output section"),
5892 exidx_shndx, exidx_relobj->name().c_str());
5893 else
5894 gold_error(_("unwinding may not work because EXIDX input section"
5895 " %u of %s is not in EXIDX output section"),
5896 exidx_shndx, exidx_relobj->name().c_str());
5898 exidx_fixup.add_exidx_cantunwind_as_needed();
5899 continue;
5902 // We need to access the contents of the EXIDX section, lock the
5903 // object here.
5904 Task_lock_obj<Object> tl(task, exidx_relobj);
5905 section_size_type exidx_size;
5906 const unsigned char* exidx_contents =
5907 exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5909 // Fix up coverage and append input section to output data list.
5910 Arm_exidx_section_offset_map* section_offset_map = NULL;
5911 uint32_t deleted_bytes =
5912 exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5913 exidx_contents,
5914 exidx_size,
5915 &section_offset_map);
5917 if (deleted_bytes == exidx_input_section->size())
5919 // The whole EXIDX section got merged. Remove it from output.
5920 gold_assert(section_offset_map == NULL);
5921 exidx_relobj->set_output_section(exidx_shndx, NULL);
5923 // All local symbols defined in this input section will be dropped.
5924 // We need to adjust output local symbol count.
5925 arm_relobj->set_output_local_symbol_count_needs_update();
5927 else if (deleted_bytes > 0)
5929 // Some entries are merged. We need to convert this EXIDX input
5930 // section into a relaxed section.
5931 gold_assert(section_offset_map != NULL);
5933 Arm_exidx_merged_section* merged_section =
5934 new Arm_exidx_merged_section(*exidx_input_section,
5935 *section_offset_map, deleted_bytes);
5936 merged_section->build_contents(exidx_contents, exidx_size);
5938 const std::string secname = exidx_relobj->section_name(exidx_shndx);
5939 this->add_relaxed_input_section(layout, merged_section, secname);
5940 arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5942 // All local symbols defined in discarded portions of this input
5943 // section will be dropped. We need to adjust output local symbol
5944 // count.
5945 arm_relobj->set_output_local_symbol_count_needs_update();
5947 else
5949 // Just add back the EXIDX input section.
5950 gold_assert(section_offset_map == NULL);
5951 const Output_section::Input_section* pis = iter->second;
5952 gold_assert(pis->is_input_section());
5953 this->add_script_input_section(*pis);
5956 processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5959 // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5960 exidx_fixup.add_exidx_cantunwind_as_needed();
5962 // Remove any known EXIDX input sections that are not processed.
5963 for (Input_section_list::const_iterator p = input_sections.begin();
5964 p != input_sections.end();
5965 ++p)
5967 if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5968 == processed_input_sections.end())
5970 // We discard a known EXIDX section because its linked
5971 // text section has been folded by ICF. We also discard an
5972 // EXIDX section with error, the output does not matter in this
5973 // case. We do this to avoid triggering asserts.
5974 Arm_relobj<big_endian>* arm_relobj =
5975 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5976 const Arm_exidx_input_section* exidx_input_section =
5977 arm_relobj->exidx_input_section_by_shndx(p->shndx());
5978 gold_assert(exidx_input_section != NULL);
5979 if (!exidx_input_section->has_errors())
5981 unsigned int text_shndx = exidx_input_section->link();
5982 gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5985 // Remove this from link. We also need to recount the
5986 // local symbols.
5987 p->relobj()->set_output_section(p->shndx(), NULL);
5988 arm_relobj->set_output_local_symbol_count_needs_update();
5992 // Link exidx output section to the first seen output section and
5993 // set correct entry size.
5994 this->set_link_section(exidx_fixup.first_output_text_section());
5995 this->set_entsize(8);
5997 // Make changes permanent.
5998 this->save_states();
5999 this->set_section_offsets_need_adjustment();
6002 // Link EXIDX output sections to text output sections.
6004 template<bool big_endian>
6005 void
6006 Arm_output_section<big_endian>::set_exidx_section_link()
6008 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
6009 if (!this->input_sections().empty())
6011 Input_section_list::const_iterator p = this->input_sections().begin();
6012 Arm_relobj<big_endian>* arm_relobj =
6013 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6014 unsigned exidx_shndx = p->shndx();
6015 const Arm_exidx_input_section* exidx_input_section =
6016 arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6017 gold_assert(exidx_input_section != NULL);
6018 unsigned int text_shndx = exidx_input_section->link();
6019 Output_section* os = arm_relobj->output_section(text_shndx);
6020 this->set_link_section(os);
6024 // Arm_relobj methods.
6026 // Determine if an input section is scannable for stub processing. SHDR is
6027 // the header of the section and SHNDX is the section index. OS is the output
6028 // section for the input section and SYMTAB is the global symbol table used to
6029 // look up ICF information.
6031 template<bool big_endian>
6032 bool
6033 Arm_relobj<big_endian>::section_is_scannable(
6034 const elfcpp::Shdr<32, big_endian>& shdr,
6035 unsigned int shndx,
6036 const Output_section* os,
6037 const Symbol_table* symtab)
6039 // Skip any empty sections, unallocated sections or sections whose
6040 // type are not SHT_PROGBITS.
6041 if (shdr.get_sh_size() == 0
6042 || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6043 || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6044 return false;
6046 // Skip any discarded or ICF'ed sections.
6047 if (os == NULL || symtab->is_section_folded(this, shndx))
6048 return false;
6050 // If this requires special offset handling, check to see if it is
6051 // a relaxed section. If this is not, then it is a merged section that
6052 // we cannot handle.
6053 if (this->is_output_section_offset_invalid(shndx))
6055 const Output_relaxed_input_section* poris =
6056 os->find_relaxed_input_section(this, shndx);
6057 if (poris == NULL)
6058 return false;
6061 return true;
6064 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6065 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6067 template<bool big_endian>
6068 bool
6069 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6070 const elfcpp::Shdr<32, big_endian>& shdr,
6071 const Relobj::Output_sections& out_sections,
6072 const Symbol_table* symtab,
6073 const unsigned char* pshdrs)
6075 unsigned int sh_type = shdr.get_sh_type();
6076 if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6077 return false;
6079 // Ignore empty section.
6080 off_t sh_size = shdr.get_sh_size();
6081 if (sh_size == 0)
6082 return false;
6084 // Ignore reloc section with unexpected symbol table. The
6085 // error will be reported in the final link.
6086 if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6087 return false;
6089 unsigned int reloc_size;
6090 if (sh_type == elfcpp::SHT_REL)
6091 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6092 else
6093 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6095 // Ignore reloc section with unexpected entsize or uneven size.
6096 // The error will be reported in the final link.
6097 if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6098 return false;
6100 // Ignore reloc section with bad info. This error will be
6101 // reported in the final link.
6102 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6103 if (index >= this->shnum())
6104 return false;
6106 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6107 const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6108 return this->section_is_scannable(text_shdr, index,
6109 out_sections[index], symtab);
6112 // Return the output address of either a plain input section or a relaxed
6113 // input section. SHNDX is the section index. We define and use this
6114 // instead of calling Output_section::output_address because that is slow
6115 // for large output.
6117 template<bool big_endian>
6118 Arm_address
6119 Arm_relobj<big_endian>::simple_input_section_output_address(
6120 unsigned int shndx,
6121 Output_section* os)
6123 if (this->is_output_section_offset_invalid(shndx))
6125 const Output_relaxed_input_section* poris =
6126 os->find_relaxed_input_section(this, shndx);
6127 // We do not handle merged sections here.
6128 gold_assert(poris != NULL);
6129 return poris->address();
6131 else
6132 return os->address() + this->get_output_section_offset(shndx);
6135 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6136 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6138 template<bool big_endian>
6139 bool
6140 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6141 const elfcpp::Shdr<32, big_endian>& shdr,
6142 unsigned int shndx,
6143 Output_section* os,
6144 const Symbol_table* symtab)
6146 if (!this->section_is_scannable(shdr, shndx, os, symtab))
6147 return false;
6149 // If the section does not cross any 4K-boundaries, it does not need to
6150 // be scanned.
6151 Arm_address address = this->simple_input_section_output_address(shndx, os);
6152 if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6153 return false;
6155 return true;
6158 // Scan a section for Cortex-A8 workaround.
6160 template<bool big_endian>
6161 void
6162 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6163 const elfcpp::Shdr<32, big_endian>& shdr,
6164 unsigned int shndx,
6165 Output_section* os,
6166 Target_arm<big_endian>* arm_target)
6168 // Look for the first mapping symbol in this section. It should be
6169 // at (shndx, 0).
6170 Mapping_symbol_position section_start(shndx, 0);
6171 typename Mapping_symbols_info::const_iterator p =
6172 this->mapping_symbols_info_.lower_bound(section_start);
6174 // There are no mapping symbols for this section. Treat it as a data-only
6175 // section. Issue a warning if section is marked as containing
6176 // instructions.
6177 if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6179 if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6180 gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6181 "erratum because it has no mapping symbols."),
6182 shndx, this->name().c_str());
6183 return;
6186 Arm_address output_address =
6187 this->simple_input_section_output_address(shndx, os);
6189 // Get the section contents.
6190 section_size_type input_view_size = 0;
6191 const unsigned char* input_view =
6192 this->section_contents(shndx, &input_view_size, false);
6194 // We need to go through the mapping symbols to determine what to
6195 // scan. There are two reasons. First, we should look at THUMB code and
6196 // THUMB code only. Second, we only want to look at the 4K-page boundary
6197 // to speed up the scanning.
6199 while (p != this->mapping_symbols_info_.end()
6200 && p->first.first == shndx)
6202 typename Mapping_symbols_info::const_iterator next =
6203 this->mapping_symbols_info_.upper_bound(p->first);
6205 // Only scan part of a section with THUMB code.
6206 if (p->second == 't')
6208 // Determine the end of this range.
6209 section_size_type span_start =
6210 convert_to_section_size_type(p->first.second);
6211 section_size_type span_end;
6212 if (next != this->mapping_symbols_info_.end()
6213 && next->first.first == shndx)
6214 span_end = convert_to_section_size_type(next->first.second);
6215 else
6216 span_end = convert_to_section_size_type(shdr.get_sh_size());
6218 if (((span_start + output_address) & ~0xfffUL)
6219 != ((span_end + output_address - 1) & ~0xfffUL))
6221 arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6222 span_start, span_end,
6223 input_view,
6224 output_address);
6228 p = next;
6232 // Scan relocations for stub generation.
6234 template<bool big_endian>
6235 void
6236 Arm_relobj<big_endian>::scan_sections_for_stubs(
6237 Target_arm<big_endian>* arm_target,
6238 const Symbol_table* symtab,
6239 const Layout* layout)
6241 unsigned int shnum = this->shnum();
6242 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6244 // Read the section headers.
6245 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6246 shnum * shdr_size,
6247 true, true);
6249 // To speed up processing, we set up hash tables for fast lookup of
6250 // input offsets to output addresses.
6251 this->initialize_input_to_output_maps();
6253 const Relobj::Output_sections& out_sections(this->output_sections());
6255 Relocate_info<32, big_endian> relinfo;
6256 relinfo.symtab = symtab;
6257 relinfo.layout = layout;
6258 relinfo.object = this;
6260 // Do relocation stubs scanning.
6261 const unsigned char* p = pshdrs + shdr_size;
6262 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6264 const elfcpp::Shdr<32, big_endian> shdr(p);
6265 if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6266 pshdrs))
6268 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6269 Arm_address output_offset = this->get_output_section_offset(index);
6270 Arm_address output_address;
6271 if (output_offset != invalid_address)
6272 output_address = out_sections[index]->address() + output_offset;
6273 else
6275 // Currently this only happens for a relaxed section.
6276 const Output_relaxed_input_section* poris =
6277 out_sections[index]->find_relaxed_input_section(this, index);
6278 gold_assert(poris != NULL);
6279 output_address = poris->address();
6282 // Get the relocations.
6283 const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6284 shdr.get_sh_size(),
6285 true, false);
6287 // Get the section contents. This does work for the case in which
6288 // we modify the contents of an input section. We need to pass the
6289 // output view under such circumstances.
6290 section_size_type input_view_size = 0;
6291 const unsigned char* input_view =
6292 this->section_contents(index, &input_view_size, false);
6294 relinfo.reloc_shndx = i;
6295 relinfo.data_shndx = index;
6296 unsigned int sh_type = shdr.get_sh_type();
6297 unsigned int reloc_size;
6298 if (sh_type == elfcpp::SHT_REL)
6299 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6300 else
6301 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6303 Output_section* os = out_sections[index];
6304 arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6305 shdr.get_sh_size() / reloc_size,
6307 output_offset == invalid_address,
6308 input_view, output_address,
6309 input_view_size);
6313 // Do Cortex-A8 erratum stubs scanning. This has to be done for a section
6314 // after its relocation section, if there is one, is processed for
6315 // relocation stubs. Merging this loop with the one above would have been
6316 // complicated since we would have had to make sure that relocation stub
6317 // scanning is done first.
6318 if (arm_target->fix_cortex_a8())
6320 const unsigned char* p = pshdrs + shdr_size;
6321 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6323 const elfcpp::Shdr<32, big_endian> shdr(p);
6324 if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6325 out_sections[i],
6326 symtab))
6327 this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6328 arm_target);
6332 // After we've done the relocations, we release the hash tables,
6333 // since we no longer need them.
6334 this->free_input_to_output_maps();
6337 // Count the local symbols. The ARM backend needs to know if a symbol
6338 // is a THUMB function or not. For global symbols, it is easy because
6339 // the Symbol object keeps the ELF symbol type. For local symbol it is
6340 // harder because we cannot access this information. So we override the
6341 // do_count_local_symbol in parent and scan local symbols to mark
6342 // THUMB functions. This is not the most efficient way but I do not want to
6343 // slow down other ports by calling a per symbol target hook inside
6344 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6346 template<bool big_endian>
6347 void
6348 Arm_relobj<big_endian>::do_count_local_symbols(
6349 Stringpool_template<char>* pool,
6350 Stringpool_template<char>* dynpool)
6352 // We need to fix-up the values of any local symbols whose type are
6353 // STT_ARM_TFUNC.
6355 // Ask parent to count the local symbols.
6356 Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6357 const unsigned int loccount = this->local_symbol_count();
6358 if (loccount == 0)
6359 return;
6361 // Initialize the thumb function bit-vector.
6362 std::vector<bool> empty_vector(loccount, false);
6363 this->local_symbol_is_thumb_function_.swap(empty_vector);
6365 // Read the symbol table section header.
6366 const unsigned int symtab_shndx = this->symtab_shndx();
6367 elfcpp::Shdr<32, big_endian>
6368 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6369 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6371 // Read the local symbols.
6372 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6373 gold_assert(loccount == symtabshdr.get_sh_info());
6374 off_t locsize = loccount * sym_size;
6375 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6376 locsize, true, true);
6378 // For mapping symbol processing, we need to read the symbol names.
6379 unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6380 if (strtab_shndx >= this->shnum())
6382 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6383 return;
6386 elfcpp::Shdr<32, big_endian>
6387 strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6388 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6390 this->error(_("symbol table name section has wrong type: %u"),
6391 static_cast<unsigned int>(strtabshdr.get_sh_type()));
6392 return;
6394 const char* pnames =
6395 reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6396 strtabshdr.get_sh_size(),
6397 false, false));
6399 // Loop over the local symbols and mark any local symbols pointing
6400 // to THUMB functions.
6402 // Skip the first dummy symbol.
6403 psyms += sym_size;
6404 typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6405 this->local_values();
6406 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6408 elfcpp::Sym<32, big_endian> sym(psyms);
6409 elfcpp::STT st_type = sym.get_st_type();
6410 Symbol_value<32>& lv((*plocal_values)[i]);
6411 Arm_address input_value = lv.input_value();
6413 // Check to see if this is a mapping symbol.
6414 const char* sym_name = pnames + sym.get_st_name();
6415 if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6417 bool is_ordinary;
6418 unsigned int input_shndx =
6419 this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6420 gold_assert(is_ordinary);
6422 // Strip of LSB in case this is a THUMB symbol.
6423 Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6424 this->mapping_symbols_info_[msp] = sym_name[1];
6427 if (st_type == elfcpp::STT_ARM_TFUNC
6428 || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6430 // This is a THUMB function. Mark this and canonicalize the
6431 // symbol value by setting LSB.
6432 this->local_symbol_is_thumb_function_[i] = true;
6433 if ((input_value & 1) == 0)
6434 lv.set_input_value(input_value | 1);
6439 // Relocate sections.
6440 template<bool big_endian>
6441 void
6442 Arm_relobj<big_endian>::do_relocate_sections(
6443 const Symbol_table* symtab,
6444 const Layout* layout,
6445 const unsigned char* pshdrs,
6446 Output_file* of,
6447 typename Sized_relobj_file<32, big_endian>::Views* pviews)
6449 // Call parent to relocate sections.
6450 Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6451 pshdrs, of, pviews);
6453 // We do not generate stubs if doing a relocatable link.
6454 if (parameters->options().relocatable())
6455 return;
6457 // Relocate stub tables.
6458 unsigned int shnum = this->shnum();
6460 Target_arm<big_endian>* arm_target =
6461 Target_arm<big_endian>::default_target();
6463 Relocate_info<32, big_endian> relinfo;
6464 relinfo.symtab = symtab;
6465 relinfo.layout = layout;
6466 relinfo.object = this;
6468 for (unsigned int i = 1; i < shnum; ++i)
6470 Arm_input_section<big_endian>* arm_input_section =
6471 arm_target->find_arm_input_section(this, i);
6473 if (arm_input_section != NULL
6474 && arm_input_section->is_stub_table_owner()
6475 && !arm_input_section->stub_table()->empty())
6477 // We cannot discard a section if it owns a stub table.
6478 Output_section* os = this->output_section(i);
6479 gold_assert(os != NULL);
6481 relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6482 relinfo.reloc_shdr = NULL;
6483 relinfo.data_shndx = i;
6484 relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6486 gold_assert((*pviews)[i].view != NULL);
6488 // We are passed the output section view. Adjust it to cover the
6489 // stub table only.
6490 Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6491 gold_assert((stub_table->address() >= (*pviews)[i].address)
6492 && ((stub_table->address() + stub_table->data_size())
6493 <= (*pviews)[i].address + (*pviews)[i].view_size));
6495 off_t offset = stub_table->address() - (*pviews)[i].address;
6496 unsigned char* view = (*pviews)[i].view + offset;
6497 Arm_address address = stub_table->address();
6498 section_size_type view_size = stub_table->data_size();
6500 stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6501 view_size);
6504 // Apply Cortex A8 workaround if applicable.
6505 if (this->section_has_cortex_a8_workaround(i))
6507 unsigned char* view = (*pviews)[i].view;
6508 Arm_address view_address = (*pviews)[i].address;
6509 section_size_type view_size = (*pviews)[i].view_size;
6510 Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6512 // Adjust view to cover section.
6513 Output_section* os = this->output_section(i);
6514 gold_assert(os != NULL);
6515 Arm_address section_address =
6516 this->simple_input_section_output_address(i, os);
6517 uint64_t section_size = this->section_size(i);
6519 gold_assert(section_address >= view_address
6520 && ((section_address + section_size)
6521 <= (view_address + view_size)));
6523 unsigned char* section_view = view + (section_address - view_address);
6525 // Apply the Cortex-A8 workaround to the output address range
6526 // corresponding to this input section.
6527 stub_table->apply_cortex_a8_workaround_to_address_range(
6528 arm_target,
6529 section_view,
6530 section_address,
6531 section_size);
6536 // Find the linked text section of an EXIDX section by looking at the first
6537 // relocation. 4.4.1 of the EHABI specifications says that an EXIDX section
6538 // must be linked to its associated code section via the sh_link field of
6539 // its section header. However, some tools are broken and the link is not
6540 // always set. LD just drops such an EXIDX section silently, causing the
6541 // associated code not unwindabled. Here we try a little bit harder to
6542 // discover the linked code section.
6544 // PSHDR points to the section header of a relocation section of an EXIDX
6545 // section. If we can find a linked text section, return true and
6546 // store the text section index in the location PSHNDX. Otherwise
6547 // return false.
6549 template<bool big_endian>
6550 bool
6551 Arm_relobj<big_endian>::find_linked_text_section(
6552 const unsigned char* pshdr,
6553 const unsigned char* psyms,
6554 unsigned int* pshndx)
6556 elfcpp::Shdr<32, big_endian> shdr(pshdr);
6558 // If there is no relocation, we cannot find the linked text section.
6559 size_t reloc_size;
6560 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6561 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6562 else
6563 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6564 size_t reloc_count = shdr.get_sh_size() / reloc_size;
6566 // Get the relocations.
6567 const unsigned char* prelocs =
6568 this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6570 // Find the REL31 relocation for the first word of the first EXIDX entry.
6571 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6573 Arm_address r_offset;
6574 typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6575 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6577 typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6578 r_info = reloc.get_r_info();
6579 r_offset = reloc.get_r_offset();
6581 else
6583 typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6584 r_info = reloc.get_r_info();
6585 r_offset = reloc.get_r_offset();
6588 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6589 if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6590 continue;
6592 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6593 if (r_sym == 0
6594 || r_sym >= this->local_symbol_count()
6595 || r_offset != 0)
6596 continue;
6598 // This is the relocation for the first word of the first EXIDX entry.
6599 // We expect to see a local section symbol.
6600 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6601 elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6602 if (sym.get_st_type() == elfcpp::STT_SECTION)
6604 bool is_ordinary;
6605 *pshndx =
6606 this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6607 gold_assert(is_ordinary);
6608 return true;
6610 else
6611 return false;
6614 return false;
6617 // Make an EXIDX input section object for an EXIDX section whose index is
6618 // SHNDX. SHDR is the section header of the EXIDX section and TEXT_SHNDX
6619 // is the section index of the linked text section.
6621 template<bool big_endian>
6622 void
6623 Arm_relobj<big_endian>::make_exidx_input_section(
6624 unsigned int shndx,
6625 const elfcpp::Shdr<32, big_endian>& shdr,
6626 unsigned int text_shndx,
6627 const elfcpp::Shdr<32, big_endian>& text_shdr)
6629 // Create an Arm_exidx_input_section object for this EXIDX section.
6630 Arm_exidx_input_section* exidx_input_section =
6631 new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6632 shdr.get_sh_addralign(),
6633 text_shdr.get_sh_size());
6635 gold_assert(this->exidx_section_map_[shndx] == NULL);
6636 this->exidx_section_map_[shndx] = exidx_input_section;
6638 if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6640 gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6641 this->section_name(shndx).c_str(), shndx, text_shndx,
6642 this->name().c_str());
6643 exidx_input_section->set_has_errors();
6645 else if (this->exidx_section_map_[text_shndx] != NULL)
6647 unsigned other_exidx_shndx =
6648 this->exidx_section_map_[text_shndx]->shndx();
6649 gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6650 "%s(%u) in %s"),
6651 this->section_name(shndx).c_str(), shndx,
6652 this->section_name(other_exidx_shndx).c_str(),
6653 other_exidx_shndx, this->section_name(text_shndx).c_str(),
6654 text_shndx, this->name().c_str());
6655 exidx_input_section->set_has_errors();
6657 else
6658 this->exidx_section_map_[text_shndx] = exidx_input_section;
6660 // Check section flags of text section.
6661 if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6663 gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6664 " in %s"),
6665 this->section_name(shndx).c_str(), shndx,
6666 this->section_name(text_shndx).c_str(), text_shndx,
6667 this->name().c_str());
6668 exidx_input_section->set_has_errors();
6670 else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6671 // I would like to make this an error but currently ld just ignores
6672 // this.
6673 gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6674 "%s(%u) in %s"),
6675 this->section_name(shndx).c_str(), shndx,
6676 this->section_name(text_shndx).c_str(), text_shndx,
6677 this->name().c_str());
6680 // Read the symbol information.
6682 template<bool big_endian>
6683 void
6684 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6686 // Call parent class to read symbol information.
6687 Sized_relobj_file<32, big_endian>::do_read_symbols(sd);
6689 // If this input file is a binary file, it has no processor
6690 // specific flags and attributes section.
6691 Input_file::Format format = this->input_file()->format();
6692 if (format != Input_file::FORMAT_ELF)
6694 gold_assert(format == Input_file::FORMAT_BINARY);
6695 this->merge_flags_and_attributes_ = false;
6696 return;
6699 // Read processor-specific flags in ELF file header.
6700 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6701 elfcpp::Elf_sizes<32>::ehdr_size,
6702 true, false);
6703 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6704 this->processor_specific_flags_ = ehdr.get_e_flags();
6706 // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6707 // sections.
6708 std::vector<unsigned int> deferred_exidx_sections;
6709 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6710 const unsigned char* pshdrs = sd->section_headers->data();
6711 const unsigned char* ps = pshdrs + shdr_size;
6712 bool must_merge_flags_and_attributes = false;
6713 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6715 elfcpp::Shdr<32, big_endian> shdr(ps);
6717 // Sometimes an object has no contents except the section name string
6718 // table and an empty symbol table with the undefined symbol. We
6719 // don't want to merge processor-specific flags from such an object.
6720 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6722 // Symbol table is not empty.
6723 const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6724 elfcpp::Elf_sizes<32>::sym_size;
6725 if (shdr.get_sh_size() > sym_size)
6726 must_merge_flags_and_attributes = true;
6728 else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6729 // If this is neither an empty symbol table nor a string table,
6730 // be conservative.
6731 must_merge_flags_and_attributes = true;
6733 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6735 gold_assert(this->attributes_section_data_ == NULL);
6736 section_offset_type section_offset = shdr.get_sh_offset();
6737 section_size_type section_size =
6738 convert_to_section_size_type(shdr.get_sh_size());
6739 const unsigned char* view =
6740 this->get_view(section_offset, section_size, true, false);
6741 this->attributes_section_data_ =
6742 new Attributes_section_data(view, section_size);
6744 else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6746 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6747 if (text_shndx == elfcpp::SHN_UNDEF)
6748 deferred_exidx_sections.push_back(i);
6749 else
6751 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6752 + text_shndx * shdr_size);
6753 this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6755 // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6756 if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6757 gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6758 this->section_name(i).c_str(), this->name().c_str());
6762 // This is rare.
6763 if (!must_merge_flags_and_attributes)
6765 gold_assert(deferred_exidx_sections.empty());
6766 this->merge_flags_and_attributes_ = false;
6767 return;
6770 // Some tools are broken and they do not set the link of EXIDX sections.
6771 // We look at the first relocation to figure out the linked sections.
6772 if (!deferred_exidx_sections.empty())
6774 // We need to go over the section headers again to find the mapping
6775 // from sections being relocated to their relocation sections. This is
6776 // a bit inefficient as we could do that in the loop above. However,
6777 // we do not expect any deferred EXIDX sections normally. So we do not
6778 // want to slow down the most common path.
6779 typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6780 Reloc_map reloc_map;
6781 ps = pshdrs + shdr_size;
6782 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6784 elfcpp::Shdr<32, big_endian> shdr(ps);
6785 elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6786 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6788 unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6789 if (info_shndx >= this->shnum())
6790 gold_error(_("relocation section %u has invalid info %u"),
6791 i, info_shndx);
6792 Reloc_map::value_type value(info_shndx, i);
6793 std::pair<Reloc_map::iterator, bool> result =
6794 reloc_map.insert(value);
6795 if (!result.second)
6796 gold_error(_("section %u has multiple relocation sections "
6797 "%u and %u"),
6798 info_shndx, i, reloc_map[info_shndx]);
6802 // Read the symbol table section header.
6803 const unsigned int symtab_shndx = this->symtab_shndx();
6804 elfcpp::Shdr<32, big_endian>
6805 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6806 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6808 // Read the local symbols.
6809 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6810 const unsigned int loccount = this->local_symbol_count();
6811 gold_assert(loccount == symtabshdr.get_sh_info());
6812 off_t locsize = loccount * sym_size;
6813 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6814 locsize, true, true);
6816 // Process the deferred EXIDX sections.
6817 for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6819 unsigned int shndx = deferred_exidx_sections[i];
6820 elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6821 unsigned int text_shndx = elfcpp::SHN_UNDEF;
6822 Reloc_map::const_iterator it = reloc_map.find(shndx);
6823 if (it != reloc_map.end())
6824 find_linked_text_section(pshdrs + it->second * shdr_size,
6825 psyms, &text_shndx);
6826 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6827 + text_shndx * shdr_size);
6828 this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6833 // Process relocations for garbage collection. The ARM target uses .ARM.exidx
6834 // sections for unwinding. These sections are referenced implicitly by
6835 // text sections linked in the section headers. If we ignore these implicit
6836 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6837 // will be garbage-collected incorrectly. Hence we override the same function
6838 // in the base class to handle these implicit references.
6840 template<bool big_endian>
6841 void
6842 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6843 Layout* layout,
6844 Read_relocs_data* rd)
6846 // First, call base class method to process relocations in this object.
6847 Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6849 // If --gc-sections is not specified, there is nothing more to do.
6850 // This happens when --icf is used but --gc-sections is not.
6851 if (!parameters->options().gc_sections())
6852 return;
6854 unsigned int shnum = this->shnum();
6855 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6856 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6857 shnum * shdr_size,
6858 true, true);
6860 // Scan section headers for sections of type SHT_ARM_EXIDX. Add references
6861 // to these from the linked text sections.
6862 const unsigned char* ps = pshdrs + shdr_size;
6863 for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6865 elfcpp::Shdr<32, big_endian> shdr(ps);
6866 if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6868 // Found an .ARM.exidx section, add it to the set of reachable
6869 // sections from its linked text section.
6870 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6871 symtab->gc()->add_reference(this, text_shndx, this, i);
6876 // Update output local symbol count. Owing to EXIDX entry merging, some local
6877 // symbols will be removed in output. Adjust output local symbol count
6878 // accordingly. We can only changed the static output local symbol count. It
6879 // is too late to change the dynamic symbols.
6881 template<bool big_endian>
6882 void
6883 Arm_relobj<big_endian>::update_output_local_symbol_count()
6885 // Caller should check that this needs updating. We want caller checking
6886 // because output_local_symbol_count_needs_update() is most likely inlined.
6887 gold_assert(this->output_local_symbol_count_needs_update_);
6889 gold_assert(this->symtab_shndx() != -1U);
6890 if (this->symtab_shndx() == 0)
6892 // This object has no symbols. Weird but legal.
6893 return;
6896 // Read the symbol table section header.
6897 const unsigned int symtab_shndx = this->symtab_shndx();
6898 elfcpp::Shdr<32, big_endian>
6899 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6900 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6902 // Read the local symbols.
6903 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6904 const unsigned int loccount = this->local_symbol_count();
6905 gold_assert(loccount == symtabshdr.get_sh_info());
6906 off_t locsize = loccount * sym_size;
6907 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6908 locsize, true, true);
6910 // Loop over the local symbols.
6912 typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6913 Output_sections;
6914 const Output_sections& out_sections(this->output_sections());
6915 unsigned int shnum = this->shnum();
6916 unsigned int count = 0;
6917 // Skip the first, dummy, symbol.
6918 psyms += sym_size;
6919 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6921 elfcpp::Sym<32, big_endian> sym(psyms);
6923 Symbol_value<32>& lv((*this->local_values())[i]);
6925 // This local symbol was already discarded by do_count_local_symbols.
6926 if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6927 continue;
6929 bool is_ordinary;
6930 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6931 &is_ordinary);
6933 if (shndx < shnum)
6935 Output_section* os = out_sections[shndx];
6937 // This local symbol no longer has an output section. Discard it.
6938 if (os == NULL)
6940 lv.set_no_output_symtab_entry();
6941 continue;
6944 // Currently we only discard parts of EXIDX input sections.
6945 // We explicitly check for a merged EXIDX input section to avoid
6946 // calling Output_section_data::output_offset unless necessary.
6947 if ((this->get_output_section_offset(shndx) == invalid_address)
6948 && (this->exidx_input_section_by_shndx(shndx) != NULL))
6950 section_offset_type output_offset =
6951 os->output_offset(this, shndx, lv.input_value());
6952 if (output_offset == -1)
6954 // This symbol is defined in a part of an EXIDX input section
6955 // that is discarded due to entry merging.
6956 lv.set_no_output_symtab_entry();
6957 continue;
6962 ++count;
6965 this->set_output_local_symbol_count(count);
6966 this->output_local_symbol_count_needs_update_ = false;
6969 // Arm_dynobj methods.
6971 // Read the symbol information.
6973 template<bool big_endian>
6974 void
6975 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6977 // Call parent class to read symbol information.
6978 Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6980 // Read processor-specific flags in ELF file header.
6981 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6982 elfcpp::Elf_sizes<32>::ehdr_size,
6983 true, false);
6984 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6985 this->processor_specific_flags_ = ehdr.get_e_flags();
6987 // Read the attributes section if there is one.
6988 // We read from the end because gas seems to put it near the end of
6989 // the section headers.
6990 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6991 const unsigned char* ps =
6992 sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6993 for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6995 elfcpp::Shdr<32, big_endian> shdr(ps);
6996 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6998 section_offset_type section_offset = shdr.get_sh_offset();
6999 section_size_type section_size =
7000 convert_to_section_size_type(shdr.get_sh_size());
7001 const unsigned char* view =
7002 this->get_view(section_offset, section_size, true, false);
7003 this->attributes_section_data_ =
7004 new Attributes_section_data(view, section_size);
7005 break;
7010 // Stub_addend_reader methods.
7012 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7014 template<bool big_endian>
7015 elfcpp::Elf_types<32>::Elf_Swxword
7016 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7017 unsigned int r_type,
7018 const unsigned char* view,
7019 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7021 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
7023 switch (r_type)
7025 case elfcpp::R_ARM_CALL:
7026 case elfcpp::R_ARM_JUMP24:
7027 case elfcpp::R_ARM_PLT32:
7029 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7030 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7031 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7032 return utils::sign_extend<26>(val << 2);
7035 case elfcpp::R_ARM_THM_CALL:
7036 case elfcpp::R_ARM_THM_JUMP24:
7037 case elfcpp::R_ARM_THM_XPC22:
7039 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7040 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7041 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7042 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7043 return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7046 case elfcpp::R_ARM_THM_JUMP19:
7048 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7049 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7050 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7051 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7052 return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7055 default:
7056 gold_unreachable();
7060 // Arm_output_data_got methods.
7062 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
7063 // The first one is initialized to be 1, which is the module index for
7064 // the main executable and the second one 0. A reloc of the type
7065 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7066 // be applied by gold. GSYM is a global symbol.
7068 template<bool big_endian>
7069 void
7070 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7071 unsigned int got_type,
7072 Symbol* gsym)
7074 if (gsym->has_got_offset(got_type))
7075 return;
7077 // We are doing a static link. Just mark it as belong to module 1,
7078 // the executable.
7079 unsigned int got_offset = this->add_constant(1);
7080 gsym->set_got_offset(got_type, got_offset);
7081 got_offset = this->add_constant(0);
7082 this->static_relocs_.push_back(Static_reloc(got_offset,
7083 elfcpp::R_ARM_TLS_DTPOFF32,
7084 gsym));
7087 // Same as the above but for a local symbol.
7089 template<bool big_endian>
7090 void
7091 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7092 unsigned int got_type,
7093 Sized_relobj_file<32, big_endian>* object,
7094 unsigned int index)
7096 if (object->local_has_got_offset(index, got_type))
7097 return;
7099 // We are doing a static link. Just mark it as belong to module 1,
7100 // the executable.
7101 unsigned int got_offset = this->add_constant(1);
7102 object->set_local_got_offset(index, got_type, got_offset);
7103 got_offset = this->add_constant(0);
7104 this->static_relocs_.push_back(Static_reloc(got_offset,
7105 elfcpp::R_ARM_TLS_DTPOFF32,
7106 object, index));
7109 template<bool big_endian>
7110 void
7111 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7113 // Call parent to write out GOT.
7114 Output_data_got<32, big_endian>::do_write(of);
7116 // We are done if there is no fix up.
7117 if (this->static_relocs_.empty())
7118 return;
7120 gold_assert(parameters->doing_static_link());
7122 const off_t offset = this->offset();
7123 const section_size_type oview_size =
7124 convert_to_section_size_type(this->data_size());
7125 unsigned char* const oview = of->get_output_view(offset, oview_size);
7127 Output_segment* tls_segment = this->layout_->tls_segment();
7128 gold_assert(tls_segment != NULL);
7130 // The thread pointer $tp points to the TCB, which is followed by the
7131 // TLS. So we need to adjust $tp relative addressing by this amount.
7132 Arm_address aligned_tcb_size =
7133 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7135 for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7137 Static_reloc& reloc(this->static_relocs_[i]);
7139 Arm_address value;
7140 if (!reloc.symbol_is_global())
7142 Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7143 const Symbol_value<32>* psymval =
7144 reloc.relobj()->local_symbol(reloc.index());
7146 // We are doing static linking. Issue an error and skip this
7147 // relocation if the symbol is undefined or in a discarded_section.
7148 bool is_ordinary;
7149 unsigned int shndx = psymval->input_shndx(&is_ordinary);
7150 if ((shndx == elfcpp::SHN_UNDEF)
7151 || (is_ordinary
7152 && shndx != elfcpp::SHN_UNDEF
7153 && !object->is_section_included(shndx)
7154 && !this->symbol_table_->is_section_folded(object, shndx)))
7156 gold_error(_("undefined or discarded local symbol %u from "
7157 " object %s in GOT"),
7158 reloc.index(), reloc.relobj()->name().c_str());
7159 continue;
7162 value = psymval->value(object, 0);
7164 else
7166 const Symbol* gsym = reloc.symbol();
7167 gold_assert(gsym != NULL);
7168 if (gsym->is_forwarder())
7169 gsym = this->symbol_table_->resolve_forwards(gsym);
7171 // We are doing static linking. Issue an error and skip this
7172 // relocation if the symbol is undefined or in a discarded_section
7173 // unless it is a weakly_undefined symbol.
7174 if ((gsym->is_defined_in_discarded_section()
7175 || gsym->is_undefined())
7176 && !gsym->is_weak_undefined())
7178 gold_error(_("undefined or discarded symbol %s in GOT"),
7179 gsym->name());
7180 continue;
7183 if (!gsym->is_weak_undefined())
7185 const Sized_symbol<32>* sym =
7186 static_cast<const Sized_symbol<32>*>(gsym);
7187 value = sym->value();
7189 else
7190 value = 0;
7193 unsigned got_offset = reloc.got_offset();
7194 gold_assert(got_offset < oview_size);
7196 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7197 Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7198 Valtype x;
7199 switch (reloc.r_type())
7201 case elfcpp::R_ARM_TLS_DTPOFF32:
7202 x = value;
7203 break;
7204 case elfcpp::R_ARM_TLS_TPOFF32:
7205 x = value + aligned_tcb_size;
7206 break;
7207 default:
7208 gold_unreachable();
7210 elfcpp::Swap<32, big_endian>::writeval(wv, x);
7213 of->write_output_view(offset, oview_size, oview);
7216 // A class to handle the PLT data.
7218 template<bool big_endian>
7219 class Output_data_plt_arm : public Output_section_data
7221 public:
7222 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7223 Reloc_section;
7225 Output_data_plt_arm(Layout*, Output_data_space*);
7227 // Add an entry to the PLT.
7228 void
7229 add_entry(Symbol* gsym);
7231 // Return the .rel.plt section data.
7232 const Reloc_section*
7233 rel_plt() const
7234 { return this->rel_; }
7236 // Return the number of PLT entries.
7237 unsigned int
7238 entry_count() const
7239 { return this->count_; }
7241 // Return the offset of the first non-reserved PLT entry.
7242 static unsigned int
7243 first_plt_entry_offset()
7244 { return sizeof(first_plt_entry); }
7246 // Return the size of a PLT entry.
7247 static unsigned int
7248 get_plt_entry_size()
7249 { return sizeof(plt_entry); }
7251 protected:
7252 void
7253 do_adjust_output_section(Output_section* os);
7255 // Write to a map file.
7256 void
7257 do_print_to_mapfile(Mapfile* mapfile) const
7258 { mapfile->print_output_data(this, _("** PLT")); }
7260 private:
7261 // Template for the first PLT entry.
7262 static const uint32_t first_plt_entry[5];
7264 // Template for subsequent PLT entries.
7265 static const uint32_t plt_entry[3];
7267 // Set the final size.
7268 void
7269 set_final_data_size()
7271 this->set_data_size(sizeof(first_plt_entry)
7272 + this->count_ * sizeof(plt_entry));
7275 // Write out the PLT data.
7276 void
7277 do_write(Output_file*);
7279 // The reloc section.
7280 Reloc_section* rel_;
7281 // The .got.plt section.
7282 Output_data_space* got_plt_;
7283 // The number of PLT entries.
7284 unsigned int count_;
7287 // Create the PLT section. The ordinary .got section is an argument,
7288 // since we need to refer to the start. We also create our own .got
7289 // section just for PLT entries.
7291 template<bool big_endian>
7292 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7293 Output_data_space* got_plt)
7294 : Output_section_data(4), got_plt_(got_plt), count_(0)
7296 this->rel_ = new Reloc_section(false);
7297 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7298 elfcpp::SHF_ALLOC, this->rel_,
7299 ORDER_DYNAMIC_PLT_RELOCS, false);
7302 template<bool big_endian>
7303 void
7304 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7306 os->set_entsize(0);
7309 // Add an entry to the PLT.
7311 template<bool big_endian>
7312 void
7313 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7315 gold_assert(!gsym->has_plt_offset());
7317 // Note that when setting the PLT offset we skip the initial
7318 // reserved PLT entry.
7319 gsym->set_plt_offset((this->count_) * sizeof(plt_entry)
7320 + sizeof(first_plt_entry));
7322 ++this->count_;
7324 section_offset_type got_offset = this->got_plt_->current_data_size();
7326 // Every PLT entry needs a GOT entry which points back to the PLT
7327 // entry (this will be changed by the dynamic linker, normally
7328 // lazily when the function is called).
7329 this->got_plt_->set_current_data_size(got_offset + 4);
7331 // Every PLT entry needs a reloc.
7332 gsym->set_needs_dynsym_entry();
7333 this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7334 got_offset);
7336 // Note that we don't need to save the symbol. The contents of the
7337 // PLT are independent of which symbols are used. The symbols only
7338 // appear in the relocations.
7341 // ARM PLTs.
7342 // FIXME: This is not very flexible. Right now this has only been tested
7343 // on armv5te. If we are to support additional architecture features like
7344 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7346 // The first entry in the PLT.
7347 template<bool big_endian>
7348 const uint32_t Output_data_plt_arm<big_endian>::first_plt_entry[5] =
7350 0xe52de004, // str lr, [sp, #-4]!
7351 0xe59fe004, // ldr lr, [pc, #4]
7352 0xe08fe00e, // add lr, pc, lr
7353 0xe5bef008, // ldr pc, [lr, #8]!
7354 0x00000000, // &GOT[0] - .
7357 // Subsequent entries in the PLT.
7359 template<bool big_endian>
7360 const uint32_t Output_data_plt_arm<big_endian>::plt_entry[3] =
7362 0xe28fc600, // add ip, pc, #0xNN00000
7363 0xe28cca00, // add ip, ip, #0xNN000
7364 0xe5bcf000, // ldr pc, [ip, #0xNNN]!
7367 // Write out the PLT. This uses the hand-coded instructions above,
7368 // and adjusts them as needed. This is all specified by the arm ELF
7369 // Processor Supplement.
7371 template<bool big_endian>
7372 void
7373 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7375 const off_t offset = this->offset();
7376 const section_size_type oview_size =
7377 convert_to_section_size_type(this->data_size());
7378 unsigned char* const oview = of->get_output_view(offset, oview_size);
7380 const off_t got_file_offset = this->got_plt_->offset();
7381 const section_size_type got_size =
7382 convert_to_section_size_type(this->got_plt_->data_size());
7383 unsigned char* const got_view = of->get_output_view(got_file_offset,
7384 got_size);
7385 unsigned char* pov = oview;
7387 Arm_address plt_address = this->address();
7388 Arm_address got_address = this->got_plt_->address();
7390 // Write first PLT entry. All but the last word are constants.
7391 const size_t num_first_plt_words = (sizeof(first_plt_entry)
7392 / sizeof(plt_entry[0]));
7393 for (size_t i = 0; i < num_first_plt_words - 1; i++)
7394 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7395 // Last word in first PLT entry is &GOT[0] - .
7396 elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7397 got_address - (plt_address + 16));
7398 pov += sizeof(first_plt_entry);
7400 unsigned char* got_pov = got_view;
7402 memset(got_pov, 0, 12);
7403 got_pov += 12;
7405 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
7406 unsigned int plt_offset = sizeof(first_plt_entry);
7407 unsigned int plt_rel_offset = 0;
7408 unsigned int got_offset = 12;
7409 const unsigned int count = this->count_;
7410 for (unsigned int i = 0;
7411 i < count;
7412 ++i,
7413 pov += sizeof(plt_entry),
7414 got_pov += 4,
7415 plt_offset += sizeof(plt_entry),
7416 plt_rel_offset += rel_size,
7417 got_offset += 4)
7419 // Set and adjust the PLT entry itself.
7420 int32_t offset = ((got_address + got_offset)
7421 - (plt_address + plt_offset + 8));
7423 gold_assert(offset >= 0 && offset < 0x0fffffff);
7424 uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7425 elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7426 uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7427 elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7428 uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7429 elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7431 // Set the entry in the GOT.
7432 elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7435 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7436 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7438 of->write_output_view(offset, oview_size, oview);
7439 of->write_output_view(got_file_offset, got_size, got_view);
7442 // Create a PLT entry for a global symbol.
7444 template<bool big_endian>
7445 void
7446 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7447 Symbol* gsym)
7449 if (gsym->has_plt_offset())
7450 return;
7452 if (this->plt_ == NULL)
7454 // Create the GOT sections first.
7455 this->got_section(symtab, layout);
7457 this->plt_ = new Output_data_plt_arm<big_endian>(layout, this->got_plt_);
7458 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7459 (elfcpp::SHF_ALLOC
7460 | elfcpp::SHF_EXECINSTR),
7461 this->plt_, ORDER_PLT, false);
7463 this->plt_->add_entry(gsym);
7466 // Return the number of entries in the PLT.
7468 template<bool big_endian>
7469 unsigned int
7470 Target_arm<big_endian>::plt_entry_count() const
7472 if (this->plt_ == NULL)
7473 return 0;
7474 return this->plt_->entry_count();
7477 // Return the offset of the first non-reserved PLT entry.
7479 template<bool big_endian>
7480 unsigned int
7481 Target_arm<big_endian>::first_plt_entry_offset() const
7483 return Output_data_plt_arm<big_endian>::first_plt_entry_offset();
7486 // Return the size of each PLT entry.
7488 template<bool big_endian>
7489 unsigned int
7490 Target_arm<big_endian>::plt_entry_size() const
7492 return Output_data_plt_arm<big_endian>::get_plt_entry_size();
7495 // Get the section to use for TLS_DESC relocations.
7497 template<bool big_endian>
7498 typename Target_arm<big_endian>::Reloc_section*
7499 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7501 return this->plt_section()->rel_tls_desc(layout);
7504 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7506 template<bool big_endian>
7507 void
7508 Target_arm<big_endian>::define_tls_base_symbol(
7509 Symbol_table* symtab,
7510 Layout* layout)
7512 if (this->tls_base_symbol_defined_)
7513 return;
7515 Output_segment* tls_segment = layout->tls_segment();
7516 if (tls_segment != NULL)
7518 bool is_exec = parameters->options().output_is_executable();
7519 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7520 Symbol_table::PREDEFINED,
7521 tls_segment, 0, 0,
7522 elfcpp::STT_TLS,
7523 elfcpp::STB_LOCAL,
7524 elfcpp::STV_HIDDEN, 0,
7525 (is_exec
7526 ? Symbol::SEGMENT_END
7527 : Symbol::SEGMENT_START),
7528 true);
7530 this->tls_base_symbol_defined_ = true;
7533 // Create a GOT entry for the TLS module index.
7535 template<bool big_endian>
7536 unsigned int
7537 Target_arm<big_endian>::got_mod_index_entry(
7538 Symbol_table* symtab,
7539 Layout* layout,
7540 Sized_relobj_file<32, big_endian>* object)
7542 if (this->got_mod_index_offset_ == -1U)
7544 gold_assert(symtab != NULL && layout != NULL && object != NULL);
7545 Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7546 unsigned int got_offset;
7547 if (!parameters->doing_static_link())
7549 got_offset = got->add_constant(0);
7550 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7551 rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7552 got_offset);
7554 else
7556 // We are doing a static link. Just mark it as belong to module 1,
7557 // the executable.
7558 got_offset = got->add_constant(1);
7561 got->add_constant(0);
7562 this->got_mod_index_offset_ = got_offset;
7564 return this->got_mod_index_offset_;
7567 // Optimize the TLS relocation type based on what we know about the
7568 // symbol. IS_FINAL is true if the final address of this symbol is
7569 // known at link time.
7571 template<bool big_endian>
7572 tls::Tls_optimization
7573 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7575 // FIXME: Currently we do not do any TLS optimization.
7576 return tls::TLSOPT_NONE;
7579 // Get the Reference_flags for a particular relocation.
7581 template<bool big_endian>
7583 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
7585 switch (r_type)
7587 case elfcpp::R_ARM_NONE:
7588 case elfcpp::R_ARM_V4BX:
7589 case elfcpp::R_ARM_GNU_VTENTRY:
7590 case elfcpp::R_ARM_GNU_VTINHERIT:
7591 // No symbol reference.
7592 return 0;
7594 case elfcpp::R_ARM_ABS32:
7595 case elfcpp::R_ARM_ABS16:
7596 case elfcpp::R_ARM_ABS12:
7597 case elfcpp::R_ARM_THM_ABS5:
7598 case elfcpp::R_ARM_ABS8:
7599 case elfcpp::R_ARM_BASE_ABS:
7600 case elfcpp::R_ARM_MOVW_ABS_NC:
7601 case elfcpp::R_ARM_MOVT_ABS:
7602 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7603 case elfcpp::R_ARM_THM_MOVT_ABS:
7604 case elfcpp::R_ARM_ABS32_NOI:
7605 return Symbol::ABSOLUTE_REF;
7607 case elfcpp::R_ARM_REL32:
7608 case elfcpp::R_ARM_LDR_PC_G0:
7609 case elfcpp::R_ARM_SBREL32:
7610 case elfcpp::R_ARM_THM_PC8:
7611 case elfcpp::R_ARM_BASE_PREL:
7612 case elfcpp::R_ARM_MOVW_PREL_NC:
7613 case elfcpp::R_ARM_MOVT_PREL:
7614 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7615 case elfcpp::R_ARM_THM_MOVT_PREL:
7616 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7617 case elfcpp::R_ARM_THM_PC12:
7618 case elfcpp::R_ARM_REL32_NOI:
7619 case elfcpp::R_ARM_ALU_PC_G0_NC:
7620 case elfcpp::R_ARM_ALU_PC_G0:
7621 case elfcpp::R_ARM_ALU_PC_G1_NC:
7622 case elfcpp::R_ARM_ALU_PC_G1:
7623 case elfcpp::R_ARM_ALU_PC_G2:
7624 case elfcpp::R_ARM_LDR_PC_G1:
7625 case elfcpp::R_ARM_LDR_PC_G2:
7626 case elfcpp::R_ARM_LDRS_PC_G0:
7627 case elfcpp::R_ARM_LDRS_PC_G1:
7628 case elfcpp::R_ARM_LDRS_PC_G2:
7629 case elfcpp::R_ARM_LDC_PC_G0:
7630 case elfcpp::R_ARM_LDC_PC_G1:
7631 case elfcpp::R_ARM_LDC_PC_G2:
7632 case elfcpp::R_ARM_ALU_SB_G0_NC:
7633 case elfcpp::R_ARM_ALU_SB_G0:
7634 case elfcpp::R_ARM_ALU_SB_G1_NC:
7635 case elfcpp::R_ARM_ALU_SB_G1:
7636 case elfcpp::R_ARM_ALU_SB_G2:
7637 case elfcpp::R_ARM_LDR_SB_G0:
7638 case elfcpp::R_ARM_LDR_SB_G1:
7639 case elfcpp::R_ARM_LDR_SB_G2:
7640 case elfcpp::R_ARM_LDRS_SB_G0:
7641 case elfcpp::R_ARM_LDRS_SB_G1:
7642 case elfcpp::R_ARM_LDRS_SB_G2:
7643 case elfcpp::R_ARM_LDC_SB_G0:
7644 case elfcpp::R_ARM_LDC_SB_G1:
7645 case elfcpp::R_ARM_LDC_SB_G2:
7646 case elfcpp::R_ARM_MOVW_BREL_NC:
7647 case elfcpp::R_ARM_MOVT_BREL:
7648 case elfcpp::R_ARM_MOVW_BREL:
7649 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7650 case elfcpp::R_ARM_THM_MOVT_BREL:
7651 case elfcpp::R_ARM_THM_MOVW_BREL:
7652 case elfcpp::R_ARM_GOTOFF32:
7653 case elfcpp::R_ARM_GOTOFF12:
7654 case elfcpp::R_ARM_SBREL31:
7655 return Symbol::RELATIVE_REF;
7657 case elfcpp::R_ARM_PLT32:
7658 case elfcpp::R_ARM_CALL:
7659 case elfcpp::R_ARM_JUMP24:
7660 case elfcpp::R_ARM_THM_CALL:
7661 case elfcpp::R_ARM_THM_JUMP24:
7662 case elfcpp::R_ARM_THM_JUMP19:
7663 case elfcpp::R_ARM_THM_JUMP6:
7664 case elfcpp::R_ARM_THM_JUMP11:
7665 case elfcpp::R_ARM_THM_JUMP8:
7666 // R_ARM_PREL31 is not used to relocate call/jump instructions but
7667 // in unwind tables. It may point to functions via PLTs.
7668 // So we treat it like call/jump relocations above.
7669 case elfcpp::R_ARM_PREL31:
7670 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
7672 case elfcpp::R_ARM_GOT_BREL:
7673 case elfcpp::R_ARM_GOT_ABS:
7674 case elfcpp::R_ARM_GOT_PREL:
7675 // Absolute in GOT.
7676 return Symbol::ABSOLUTE_REF;
7678 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7679 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7680 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7681 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7682 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7683 return Symbol::TLS_REF;
7685 case elfcpp::R_ARM_TARGET1:
7686 case elfcpp::R_ARM_TARGET2:
7687 case elfcpp::R_ARM_COPY:
7688 case elfcpp::R_ARM_GLOB_DAT:
7689 case elfcpp::R_ARM_JUMP_SLOT:
7690 case elfcpp::R_ARM_RELATIVE:
7691 case elfcpp::R_ARM_PC24:
7692 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7693 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7694 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7695 default:
7696 // Not expected. We will give an error later.
7697 return 0;
7701 // Report an unsupported relocation against a local symbol.
7703 template<bool big_endian>
7704 void
7705 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7706 Sized_relobj_file<32, big_endian>* object,
7707 unsigned int r_type)
7709 gold_error(_("%s: unsupported reloc %u against local symbol"),
7710 object->name().c_str(), r_type);
7713 // We are about to emit a dynamic relocation of type R_TYPE. If the
7714 // dynamic linker does not support it, issue an error. The GNU linker
7715 // only issues a non-PIC error for an allocated read-only section.
7716 // Here we know the section is allocated, but we don't know that it is
7717 // read-only. But we check for all the relocation types which the
7718 // glibc dynamic linker supports, so it seems appropriate to issue an
7719 // error even if the section is not read-only.
7721 template<bool big_endian>
7722 void
7723 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7724 unsigned int r_type)
7726 switch (r_type)
7728 // These are the relocation types supported by glibc for ARM.
7729 case elfcpp::R_ARM_RELATIVE:
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_ABS32:
7734 case elfcpp::R_ARM_ABS32_NOI:
7735 case elfcpp::R_ARM_PC24:
7736 // FIXME: The following 3 types are not supported by Android's dynamic
7737 // linker.
7738 case elfcpp::R_ARM_TLS_DTPMOD32:
7739 case elfcpp::R_ARM_TLS_DTPOFF32:
7740 case elfcpp::R_ARM_TLS_TPOFF32:
7741 return;
7743 default:
7745 // This prevents us from issuing more than one error per reloc
7746 // section. But we can still wind up issuing more than one
7747 // error per object file.
7748 if (this->issued_non_pic_error_)
7749 return;
7750 const Arm_reloc_property* reloc_property =
7751 arm_reloc_property_table->get_reloc_property(r_type);
7752 gold_assert(reloc_property != NULL);
7753 object->error(_("requires unsupported dynamic reloc %s; "
7754 "recompile with -fPIC"),
7755 reloc_property->name().c_str());
7756 this->issued_non_pic_error_ = true;
7757 return;
7760 case elfcpp::R_ARM_NONE:
7761 gold_unreachable();
7765 // Scan a relocation for a local symbol.
7766 // FIXME: This only handles a subset of relocation types used by Android
7767 // on ARM v5te devices.
7769 template<bool big_endian>
7770 inline void
7771 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7772 Layout* layout,
7773 Target_arm* target,
7774 Sized_relobj_file<32, big_endian>* object,
7775 unsigned int data_shndx,
7776 Output_section* output_section,
7777 const elfcpp::Rel<32, big_endian>& reloc,
7778 unsigned int r_type,
7779 const elfcpp::Sym<32, big_endian>& lsym)
7781 r_type = get_real_reloc_type(r_type);
7782 switch (r_type)
7784 case elfcpp::R_ARM_NONE:
7785 case elfcpp::R_ARM_V4BX:
7786 case elfcpp::R_ARM_GNU_VTENTRY:
7787 case elfcpp::R_ARM_GNU_VTINHERIT:
7788 break;
7790 case elfcpp::R_ARM_ABS32:
7791 case elfcpp::R_ARM_ABS32_NOI:
7792 // If building a shared library (or a position-independent
7793 // executable), we need to create a dynamic relocation for
7794 // this location. The relocation applied at link time will
7795 // apply the link-time value, so we flag the location with
7796 // an R_ARM_RELATIVE relocation so the dynamic loader can
7797 // relocate it easily.
7798 if (parameters->options().output_is_position_independent())
7800 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7801 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7802 // If we are to add more other reloc types than R_ARM_ABS32,
7803 // we need to add check_non_pic(object, r_type) here.
7804 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7805 output_section, data_shndx,
7806 reloc.get_r_offset());
7808 break;
7810 case elfcpp::R_ARM_ABS16:
7811 case elfcpp::R_ARM_ABS12:
7812 case elfcpp::R_ARM_THM_ABS5:
7813 case elfcpp::R_ARM_ABS8:
7814 case elfcpp::R_ARM_BASE_ABS:
7815 case elfcpp::R_ARM_MOVW_ABS_NC:
7816 case elfcpp::R_ARM_MOVT_ABS:
7817 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7818 case elfcpp::R_ARM_THM_MOVT_ABS:
7819 // If building a shared library (or a position-independent
7820 // executable), we need to create a dynamic relocation for
7821 // this location. Because the addend needs to remain in the
7822 // data section, we need to be careful not to apply this
7823 // relocation statically.
7824 if (parameters->options().output_is_position_independent())
7826 check_non_pic(object, r_type);
7827 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7828 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7829 if (lsym.get_st_type() != elfcpp::STT_SECTION)
7830 rel_dyn->add_local(object, r_sym, r_type, output_section,
7831 data_shndx, reloc.get_r_offset());
7832 else
7834 gold_assert(lsym.get_st_value() == 0);
7835 unsigned int shndx = lsym.get_st_shndx();
7836 bool is_ordinary;
7837 shndx = object->adjust_sym_shndx(r_sym, shndx,
7838 &is_ordinary);
7839 if (!is_ordinary)
7840 object->error(_("section symbol %u has bad shndx %u"),
7841 r_sym, shndx);
7842 else
7843 rel_dyn->add_local_section(object, shndx,
7844 r_type, output_section,
7845 data_shndx, reloc.get_r_offset());
7848 break;
7850 case elfcpp::R_ARM_REL32:
7851 case elfcpp::R_ARM_LDR_PC_G0:
7852 case elfcpp::R_ARM_SBREL32:
7853 case elfcpp::R_ARM_THM_CALL:
7854 case elfcpp::R_ARM_THM_PC8:
7855 case elfcpp::R_ARM_BASE_PREL:
7856 case elfcpp::R_ARM_PLT32:
7857 case elfcpp::R_ARM_CALL:
7858 case elfcpp::R_ARM_JUMP24:
7859 case elfcpp::R_ARM_THM_JUMP24:
7860 case elfcpp::R_ARM_SBREL31:
7861 case elfcpp::R_ARM_PREL31:
7862 case elfcpp::R_ARM_MOVW_PREL_NC:
7863 case elfcpp::R_ARM_MOVT_PREL:
7864 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7865 case elfcpp::R_ARM_THM_MOVT_PREL:
7866 case elfcpp::R_ARM_THM_JUMP19:
7867 case elfcpp::R_ARM_THM_JUMP6:
7868 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7869 case elfcpp::R_ARM_THM_PC12:
7870 case elfcpp::R_ARM_REL32_NOI:
7871 case elfcpp::R_ARM_ALU_PC_G0_NC:
7872 case elfcpp::R_ARM_ALU_PC_G0:
7873 case elfcpp::R_ARM_ALU_PC_G1_NC:
7874 case elfcpp::R_ARM_ALU_PC_G1:
7875 case elfcpp::R_ARM_ALU_PC_G2:
7876 case elfcpp::R_ARM_LDR_PC_G1:
7877 case elfcpp::R_ARM_LDR_PC_G2:
7878 case elfcpp::R_ARM_LDRS_PC_G0:
7879 case elfcpp::R_ARM_LDRS_PC_G1:
7880 case elfcpp::R_ARM_LDRS_PC_G2:
7881 case elfcpp::R_ARM_LDC_PC_G0:
7882 case elfcpp::R_ARM_LDC_PC_G1:
7883 case elfcpp::R_ARM_LDC_PC_G2:
7884 case elfcpp::R_ARM_ALU_SB_G0_NC:
7885 case elfcpp::R_ARM_ALU_SB_G0:
7886 case elfcpp::R_ARM_ALU_SB_G1_NC:
7887 case elfcpp::R_ARM_ALU_SB_G1:
7888 case elfcpp::R_ARM_ALU_SB_G2:
7889 case elfcpp::R_ARM_LDR_SB_G0:
7890 case elfcpp::R_ARM_LDR_SB_G1:
7891 case elfcpp::R_ARM_LDR_SB_G2:
7892 case elfcpp::R_ARM_LDRS_SB_G0:
7893 case elfcpp::R_ARM_LDRS_SB_G1:
7894 case elfcpp::R_ARM_LDRS_SB_G2:
7895 case elfcpp::R_ARM_LDC_SB_G0:
7896 case elfcpp::R_ARM_LDC_SB_G1:
7897 case elfcpp::R_ARM_LDC_SB_G2:
7898 case elfcpp::R_ARM_MOVW_BREL_NC:
7899 case elfcpp::R_ARM_MOVT_BREL:
7900 case elfcpp::R_ARM_MOVW_BREL:
7901 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7902 case elfcpp::R_ARM_THM_MOVT_BREL:
7903 case elfcpp::R_ARM_THM_MOVW_BREL:
7904 case elfcpp::R_ARM_THM_JUMP11:
7905 case elfcpp::R_ARM_THM_JUMP8:
7906 // We don't need to do anything for a relative addressing relocation
7907 // against a local symbol if it does not reference the GOT.
7908 break;
7910 case elfcpp::R_ARM_GOTOFF32:
7911 case elfcpp::R_ARM_GOTOFF12:
7912 // We need a GOT section:
7913 target->got_section(symtab, layout);
7914 break;
7916 case elfcpp::R_ARM_GOT_BREL:
7917 case elfcpp::R_ARM_GOT_PREL:
7919 // The symbol requires a GOT entry.
7920 Arm_output_data_got<big_endian>* got =
7921 target->got_section(symtab, layout);
7922 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7923 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
7925 // If we are generating a shared object, we need to add a
7926 // dynamic RELATIVE relocation for this symbol's GOT entry.
7927 if (parameters->options().output_is_position_independent())
7929 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7930 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7931 rel_dyn->add_local_relative(
7932 object, r_sym, elfcpp::R_ARM_RELATIVE, got,
7933 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
7937 break;
7939 case elfcpp::R_ARM_TARGET1:
7940 case elfcpp::R_ARM_TARGET2:
7941 // This should have been mapped to another type already.
7942 // Fall through.
7943 case elfcpp::R_ARM_COPY:
7944 case elfcpp::R_ARM_GLOB_DAT:
7945 case elfcpp::R_ARM_JUMP_SLOT:
7946 case elfcpp::R_ARM_RELATIVE:
7947 // These are relocations which should only be seen by the
7948 // dynamic linker, and should never be seen here.
7949 gold_error(_("%s: unexpected reloc %u in object file"),
7950 object->name().c_str(), r_type);
7951 break;
7954 // These are initial TLS relocs, which are expected when
7955 // linking.
7956 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7957 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7958 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7959 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7960 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7962 bool output_is_shared = parameters->options().shared();
7963 const tls::Tls_optimization optimized_type
7964 = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
7965 r_type);
7966 switch (r_type)
7968 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7969 if (optimized_type == tls::TLSOPT_NONE)
7971 // Create a pair of GOT entries for the module index and
7972 // dtv-relative offset.
7973 Arm_output_data_got<big_endian>* got
7974 = target->got_section(symtab, layout);
7975 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7976 unsigned int shndx = lsym.get_st_shndx();
7977 bool is_ordinary;
7978 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
7979 if (!is_ordinary)
7981 object->error(_("local symbol %u has bad shndx %u"),
7982 r_sym, shndx);
7983 break;
7986 if (!parameters->doing_static_link())
7987 got->add_local_pair_with_rel(object, r_sym, shndx,
7988 GOT_TYPE_TLS_PAIR,
7989 target->rel_dyn_section(layout),
7990 elfcpp::R_ARM_TLS_DTPMOD32, 0);
7991 else
7992 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
7993 object, r_sym);
7995 else
7996 // FIXME: TLS optimization not supported yet.
7997 gold_unreachable();
7998 break;
8000 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8001 if (optimized_type == tls::TLSOPT_NONE)
8003 // Create a GOT entry for the module index.
8004 target->got_mod_index_entry(symtab, layout, object);
8006 else
8007 // FIXME: TLS optimization not supported yet.
8008 gold_unreachable();
8009 break;
8011 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8012 break;
8014 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8015 layout->set_has_static_tls();
8016 if (optimized_type == tls::TLSOPT_NONE)
8018 // Create a GOT entry for the tp-relative offset.
8019 Arm_output_data_got<big_endian>* got
8020 = target->got_section(symtab, layout);
8021 unsigned int r_sym =
8022 elfcpp::elf_r_sym<32>(reloc.get_r_info());
8023 if (!parameters->doing_static_link())
8024 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
8025 target->rel_dyn_section(layout),
8026 elfcpp::R_ARM_TLS_TPOFF32);
8027 else if (!object->local_has_got_offset(r_sym,
8028 GOT_TYPE_TLS_OFFSET))
8030 got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
8031 unsigned int got_offset =
8032 object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
8033 got->add_static_reloc(got_offset,
8034 elfcpp::R_ARM_TLS_TPOFF32, object,
8035 r_sym);
8038 else
8039 // FIXME: TLS optimization not supported yet.
8040 gold_unreachable();
8041 break;
8043 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8044 layout->set_has_static_tls();
8045 if (output_is_shared)
8047 // We need to create a dynamic relocation.
8048 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8049 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8050 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8051 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8052 output_section, data_shndx,
8053 reloc.get_r_offset());
8055 break;
8057 default:
8058 gold_unreachable();
8061 break;
8063 case elfcpp::R_ARM_PC24:
8064 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8065 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8066 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8067 default:
8068 unsupported_reloc_local(object, r_type);
8069 break;
8073 // Report an unsupported relocation against a global symbol.
8075 template<bool big_endian>
8076 void
8077 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8078 Sized_relobj_file<32, big_endian>* object,
8079 unsigned int r_type,
8080 Symbol* gsym)
8082 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8083 object->name().c_str(), r_type, gsym->demangled_name().c_str());
8086 template<bool big_endian>
8087 inline bool
8088 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8089 unsigned int r_type)
8091 switch (r_type)
8093 case elfcpp::R_ARM_PC24:
8094 case elfcpp::R_ARM_THM_CALL:
8095 case elfcpp::R_ARM_PLT32:
8096 case elfcpp::R_ARM_CALL:
8097 case elfcpp::R_ARM_JUMP24:
8098 case elfcpp::R_ARM_THM_JUMP24:
8099 case elfcpp::R_ARM_SBREL31:
8100 case elfcpp::R_ARM_PREL31:
8101 case elfcpp::R_ARM_THM_JUMP19:
8102 case elfcpp::R_ARM_THM_JUMP6:
8103 case elfcpp::R_ARM_THM_JUMP11:
8104 case elfcpp::R_ARM_THM_JUMP8:
8105 // All the relocations above are branches except SBREL31 and PREL31.
8106 return false;
8108 default:
8109 // Be conservative and assume this is a function pointer.
8110 return true;
8114 template<bool big_endian>
8115 inline bool
8116 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8117 Symbol_table*,
8118 Layout*,
8119 Target_arm<big_endian>* target,
8120 Sized_relobj_file<32, big_endian>*,
8121 unsigned int,
8122 Output_section*,
8123 const elfcpp::Rel<32, big_endian>&,
8124 unsigned int r_type,
8125 const elfcpp::Sym<32, big_endian>&)
8127 r_type = target->get_real_reloc_type(r_type);
8128 return possible_function_pointer_reloc(r_type);
8131 template<bool big_endian>
8132 inline bool
8133 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8134 Symbol_table*,
8135 Layout*,
8136 Target_arm<big_endian>* target,
8137 Sized_relobj_file<32, big_endian>*,
8138 unsigned int,
8139 Output_section*,
8140 const elfcpp::Rel<32, big_endian>&,
8141 unsigned int r_type,
8142 Symbol* gsym)
8144 // GOT is not a function.
8145 if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8146 return false;
8148 r_type = target->get_real_reloc_type(r_type);
8149 return possible_function_pointer_reloc(r_type);
8152 // Scan a relocation for a global symbol.
8154 template<bool big_endian>
8155 inline void
8156 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8157 Layout* layout,
8158 Target_arm* target,
8159 Sized_relobj_file<32, big_endian>* object,
8160 unsigned int data_shndx,
8161 Output_section* output_section,
8162 const elfcpp::Rel<32, big_endian>& reloc,
8163 unsigned int r_type,
8164 Symbol* gsym)
8166 // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8167 // section. We check here to avoid creating a dynamic reloc against
8168 // _GLOBAL_OFFSET_TABLE_.
8169 if (!target->has_got_section()
8170 && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8171 target->got_section(symtab, layout);
8173 r_type = get_real_reloc_type(r_type);
8174 switch (r_type)
8176 case elfcpp::R_ARM_NONE:
8177 case elfcpp::R_ARM_V4BX:
8178 case elfcpp::R_ARM_GNU_VTENTRY:
8179 case elfcpp::R_ARM_GNU_VTINHERIT:
8180 break;
8182 case elfcpp::R_ARM_ABS32:
8183 case elfcpp::R_ARM_ABS16:
8184 case elfcpp::R_ARM_ABS12:
8185 case elfcpp::R_ARM_THM_ABS5:
8186 case elfcpp::R_ARM_ABS8:
8187 case elfcpp::R_ARM_BASE_ABS:
8188 case elfcpp::R_ARM_MOVW_ABS_NC:
8189 case elfcpp::R_ARM_MOVT_ABS:
8190 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8191 case elfcpp::R_ARM_THM_MOVT_ABS:
8192 case elfcpp::R_ARM_ABS32_NOI:
8193 // Absolute addressing relocations.
8195 // Make a PLT entry if necessary.
8196 if (this->symbol_needs_plt_entry(gsym))
8198 target->make_plt_entry(symtab, layout, gsym);
8199 // Since this is not a PC-relative relocation, we may be
8200 // taking the address of a function. In that case we need to
8201 // set the entry in the dynamic symbol table to the address of
8202 // the PLT entry.
8203 if (gsym->is_from_dynobj() && !parameters->options().shared())
8204 gsym->set_needs_dynsym_value();
8206 // Make a dynamic relocation if necessary.
8207 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8209 if (gsym->may_need_copy_reloc())
8211 target->copy_reloc(symtab, layout, object,
8212 data_shndx, output_section, gsym, reloc);
8214 else if ((r_type == elfcpp::R_ARM_ABS32
8215 || r_type == elfcpp::R_ARM_ABS32_NOI)
8216 && gsym->can_use_relative_reloc(false))
8218 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8219 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8220 output_section, object,
8221 data_shndx, reloc.get_r_offset());
8223 else
8225 check_non_pic(object, r_type);
8226 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8227 rel_dyn->add_global(gsym, r_type, output_section, object,
8228 data_shndx, reloc.get_r_offset());
8232 break;
8234 case elfcpp::R_ARM_GOTOFF32:
8235 case elfcpp::R_ARM_GOTOFF12:
8236 // We need a GOT section.
8237 target->got_section(symtab, layout);
8238 break;
8240 case elfcpp::R_ARM_REL32:
8241 case elfcpp::R_ARM_LDR_PC_G0:
8242 case elfcpp::R_ARM_SBREL32:
8243 case elfcpp::R_ARM_THM_PC8:
8244 case elfcpp::R_ARM_BASE_PREL:
8245 case elfcpp::R_ARM_MOVW_PREL_NC:
8246 case elfcpp::R_ARM_MOVT_PREL:
8247 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8248 case elfcpp::R_ARM_THM_MOVT_PREL:
8249 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8250 case elfcpp::R_ARM_THM_PC12:
8251 case elfcpp::R_ARM_REL32_NOI:
8252 case elfcpp::R_ARM_ALU_PC_G0_NC:
8253 case elfcpp::R_ARM_ALU_PC_G0:
8254 case elfcpp::R_ARM_ALU_PC_G1_NC:
8255 case elfcpp::R_ARM_ALU_PC_G1:
8256 case elfcpp::R_ARM_ALU_PC_G2:
8257 case elfcpp::R_ARM_LDR_PC_G1:
8258 case elfcpp::R_ARM_LDR_PC_G2:
8259 case elfcpp::R_ARM_LDRS_PC_G0:
8260 case elfcpp::R_ARM_LDRS_PC_G1:
8261 case elfcpp::R_ARM_LDRS_PC_G2:
8262 case elfcpp::R_ARM_LDC_PC_G0:
8263 case elfcpp::R_ARM_LDC_PC_G1:
8264 case elfcpp::R_ARM_LDC_PC_G2:
8265 case elfcpp::R_ARM_ALU_SB_G0_NC:
8266 case elfcpp::R_ARM_ALU_SB_G0:
8267 case elfcpp::R_ARM_ALU_SB_G1_NC:
8268 case elfcpp::R_ARM_ALU_SB_G1:
8269 case elfcpp::R_ARM_ALU_SB_G2:
8270 case elfcpp::R_ARM_LDR_SB_G0:
8271 case elfcpp::R_ARM_LDR_SB_G1:
8272 case elfcpp::R_ARM_LDR_SB_G2:
8273 case elfcpp::R_ARM_LDRS_SB_G0:
8274 case elfcpp::R_ARM_LDRS_SB_G1:
8275 case elfcpp::R_ARM_LDRS_SB_G2:
8276 case elfcpp::R_ARM_LDC_SB_G0:
8277 case elfcpp::R_ARM_LDC_SB_G1:
8278 case elfcpp::R_ARM_LDC_SB_G2:
8279 case elfcpp::R_ARM_MOVW_BREL_NC:
8280 case elfcpp::R_ARM_MOVT_BREL:
8281 case elfcpp::R_ARM_MOVW_BREL:
8282 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8283 case elfcpp::R_ARM_THM_MOVT_BREL:
8284 case elfcpp::R_ARM_THM_MOVW_BREL:
8285 // Relative addressing relocations.
8287 // Make a dynamic relocation if necessary.
8288 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8290 if (target->may_need_copy_reloc(gsym))
8292 target->copy_reloc(symtab, layout, object,
8293 data_shndx, output_section, gsym, reloc);
8295 else
8297 check_non_pic(object, r_type);
8298 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8299 rel_dyn->add_global(gsym, r_type, output_section, object,
8300 data_shndx, reloc.get_r_offset());
8304 break;
8306 case elfcpp::R_ARM_THM_CALL:
8307 case elfcpp::R_ARM_PLT32:
8308 case elfcpp::R_ARM_CALL:
8309 case elfcpp::R_ARM_JUMP24:
8310 case elfcpp::R_ARM_THM_JUMP24:
8311 case elfcpp::R_ARM_SBREL31:
8312 case elfcpp::R_ARM_PREL31:
8313 case elfcpp::R_ARM_THM_JUMP19:
8314 case elfcpp::R_ARM_THM_JUMP6:
8315 case elfcpp::R_ARM_THM_JUMP11:
8316 case elfcpp::R_ARM_THM_JUMP8:
8317 // All the relocation above are branches except for the PREL31 ones.
8318 // A PREL31 relocation can point to a personality function in a shared
8319 // library. In that case we want to use a PLT because we want to
8320 // call the personality routine and the dynamic linkers we care about
8321 // do not support dynamic PREL31 relocations. An REL31 relocation may
8322 // point to a function whose unwinding behaviour is being described but
8323 // we will not mistakenly generate a PLT for that because we should use
8324 // a local section symbol.
8326 // If the symbol is fully resolved, this is just a relative
8327 // local reloc. Otherwise we need a PLT entry.
8328 if (gsym->final_value_is_known())
8329 break;
8330 // If building a shared library, we can also skip the PLT entry
8331 // if the symbol is defined in the output file and is protected
8332 // or hidden.
8333 if (gsym->is_defined()
8334 && !gsym->is_from_dynobj()
8335 && !gsym->is_preemptible())
8336 break;
8337 target->make_plt_entry(symtab, layout, gsym);
8338 break;
8340 case elfcpp::R_ARM_GOT_BREL:
8341 case elfcpp::R_ARM_GOT_ABS:
8342 case elfcpp::R_ARM_GOT_PREL:
8344 // The symbol requires a GOT entry.
8345 Arm_output_data_got<big_endian>* got =
8346 target->got_section(symtab, layout);
8347 if (gsym->final_value_is_known())
8348 got->add_global(gsym, GOT_TYPE_STANDARD);
8349 else
8351 // If this symbol is not fully resolved, we need to add a
8352 // GOT entry with a dynamic relocation.
8353 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8354 if (gsym->is_from_dynobj()
8355 || gsym->is_undefined()
8356 || gsym->is_preemptible())
8357 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8358 rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8359 else
8361 if (got->add_global(gsym, GOT_TYPE_STANDARD))
8362 rel_dyn->add_global_relative(
8363 gsym, elfcpp::R_ARM_RELATIVE, got,
8364 gsym->got_offset(GOT_TYPE_STANDARD));
8368 break;
8370 case elfcpp::R_ARM_TARGET1:
8371 case elfcpp::R_ARM_TARGET2:
8372 // These should have been mapped to other types already.
8373 // Fall through.
8374 case elfcpp::R_ARM_COPY:
8375 case elfcpp::R_ARM_GLOB_DAT:
8376 case elfcpp::R_ARM_JUMP_SLOT:
8377 case elfcpp::R_ARM_RELATIVE:
8378 // These are relocations which should only be seen by the
8379 // dynamic linker, and should never be seen here.
8380 gold_error(_("%s: unexpected reloc %u in object file"),
8381 object->name().c_str(), r_type);
8382 break;
8384 // These are initial tls relocs, which are expected when
8385 // linking.
8386 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8387 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8388 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8389 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8390 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8392 const bool is_final = gsym->final_value_is_known();
8393 const tls::Tls_optimization optimized_type
8394 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8395 switch (r_type)
8397 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8398 if (optimized_type == tls::TLSOPT_NONE)
8400 // Create a pair of GOT entries for the module index and
8401 // dtv-relative offset.
8402 Arm_output_data_got<big_endian>* got
8403 = target->got_section(symtab, layout);
8404 if (!parameters->doing_static_link())
8405 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8406 target->rel_dyn_section(layout),
8407 elfcpp::R_ARM_TLS_DTPMOD32,
8408 elfcpp::R_ARM_TLS_DTPOFF32);
8409 else
8410 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8412 else
8413 // FIXME: TLS optimization not supported yet.
8414 gold_unreachable();
8415 break;
8417 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8418 if (optimized_type == tls::TLSOPT_NONE)
8420 // Create a GOT entry for the module index.
8421 target->got_mod_index_entry(symtab, layout, object);
8423 else
8424 // FIXME: TLS optimization not supported yet.
8425 gold_unreachable();
8426 break;
8428 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8429 break;
8431 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8432 layout->set_has_static_tls();
8433 if (optimized_type == tls::TLSOPT_NONE)
8435 // Create a GOT entry for the tp-relative offset.
8436 Arm_output_data_got<big_endian>* got
8437 = target->got_section(symtab, layout);
8438 if (!parameters->doing_static_link())
8439 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
8440 target->rel_dyn_section(layout),
8441 elfcpp::R_ARM_TLS_TPOFF32);
8442 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
8444 got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
8445 unsigned int got_offset =
8446 gsym->got_offset(GOT_TYPE_TLS_OFFSET);
8447 got->add_static_reloc(got_offset,
8448 elfcpp::R_ARM_TLS_TPOFF32, gsym);
8451 else
8452 // FIXME: TLS optimization not supported yet.
8453 gold_unreachable();
8454 break;
8456 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8457 layout->set_has_static_tls();
8458 if (parameters->options().shared())
8460 // We need to create a dynamic relocation.
8461 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8462 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
8463 output_section, object,
8464 data_shndx, reloc.get_r_offset());
8466 break;
8468 default:
8469 gold_unreachable();
8472 break;
8474 case elfcpp::R_ARM_PC24:
8475 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8476 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8477 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8478 default:
8479 unsupported_reloc_global(object, r_type, gsym);
8480 break;
8484 // Process relocations for gc.
8486 template<bool big_endian>
8487 void
8488 Target_arm<big_endian>::gc_process_relocs(
8489 Symbol_table* symtab,
8490 Layout* layout,
8491 Sized_relobj_file<32, big_endian>* object,
8492 unsigned int data_shndx,
8493 unsigned int,
8494 const unsigned char* prelocs,
8495 size_t reloc_count,
8496 Output_section* output_section,
8497 bool needs_special_offset_handling,
8498 size_t local_symbol_count,
8499 const unsigned char* plocal_symbols)
8501 typedef Target_arm<big_endian> Arm;
8502 typedef typename Target_arm<big_endian>::Scan Scan;
8504 gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
8505 typename Target_arm::Relocatable_size_for_reloc>(
8506 symtab,
8507 layout,
8508 this,
8509 object,
8510 data_shndx,
8511 prelocs,
8512 reloc_count,
8513 output_section,
8514 needs_special_offset_handling,
8515 local_symbol_count,
8516 plocal_symbols);
8519 // Scan relocations for a section.
8521 template<bool big_endian>
8522 void
8523 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
8524 Layout* layout,
8525 Sized_relobj_file<32, big_endian>* object,
8526 unsigned int data_shndx,
8527 unsigned int sh_type,
8528 const unsigned char* prelocs,
8529 size_t reloc_count,
8530 Output_section* output_section,
8531 bool needs_special_offset_handling,
8532 size_t local_symbol_count,
8533 const unsigned char* plocal_symbols)
8535 typedef typename Target_arm<big_endian>::Scan Scan;
8536 if (sh_type == elfcpp::SHT_RELA)
8538 gold_error(_("%s: unsupported RELA reloc section"),
8539 object->name().c_str());
8540 return;
8543 gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
8544 symtab,
8545 layout,
8546 this,
8547 object,
8548 data_shndx,
8549 prelocs,
8550 reloc_count,
8551 output_section,
8552 needs_special_offset_handling,
8553 local_symbol_count,
8554 plocal_symbols);
8557 // Finalize the sections.
8559 template<bool big_endian>
8560 void
8561 Target_arm<big_endian>::do_finalize_sections(
8562 Layout* layout,
8563 const Input_objects* input_objects,
8564 Symbol_table* symtab)
8566 bool merged_any_attributes = false;
8567 // Merge processor-specific flags.
8568 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
8569 p != input_objects->relobj_end();
8570 ++p)
8572 Arm_relobj<big_endian>* arm_relobj =
8573 Arm_relobj<big_endian>::as_arm_relobj(*p);
8574 if (arm_relobj->merge_flags_and_attributes())
8576 this->merge_processor_specific_flags(
8577 arm_relobj->name(),
8578 arm_relobj->processor_specific_flags());
8579 this->merge_object_attributes(arm_relobj->name().c_str(),
8580 arm_relobj->attributes_section_data());
8581 merged_any_attributes = true;
8585 for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
8586 p != input_objects->dynobj_end();
8587 ++p)
8589 Arm_dynobj<big_endian>* arm_dynobj =
8590 Arm_dynobj<big_endian>::as_arm_dynobj(*p);
8591 this->merge_processor_specific_flags(
8592 arm_dynobj->name(),
8593 arm_dynobj->processor_specific_flags());
8594 this->merge_object_attributes(arm_dynobj->name().c_str(),
8595 arm_dynobj->attributes_section_data());
8596 merged_any_attributes = true;
8599 // Create an empty uninitialized attribute section if we still don't have it
8600 // at this moment. This happens if there is no attributes sections in all
8601 // inputs.
8602 if (this->attributes_section_data_ == NULL)
8603 this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
8605 // Check BLX use.
8606 const Object_attribute* cpu_arch_attr =
8607 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
8608 if (cpu_arch_attr->int_value() > elfcpp::TAG_CPU_ARCH_V4)
8609 this->set_may_use_blx(true);
8611 // Check if we need to use Cortex-A8 workaround.
8612 if (parameters->options().user_set_fix_cortex_a8())
8613 this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
8614 else
8616 // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
8617 // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
8618 // profile.
8619 const Object_attribute* cpu_arch_profile_attr =
8620 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
8621 this->fix_cortex_a8_ =
8622 (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
8623 && (cpu_arch_profile_attr->int_value() == 'A'
8624 || cpu_arch_profile_attr->int_value() == 0));
8627 // Check if we can use V4BX interworking.
8628 // The V4BX interworking stub contains BX instruction,
8629 // which is not specified for some profiles.
8630 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
8631 && !this->may_use_blx())
8632 gold_error(_("unable to provide V4BX reloc interworking fix up; "
8633 "the target profile does not support BX instruction"));
8635 // Fill in some more dynamic tags.
8636 const Reloc_section* rel_plt = (this->plt_ == NULL
8637 ? NULL
8638 : this->plt_->rel_plt());
8639 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
8640 this->rel_dyn_, true, false);
8642 // Emit any relocs we saved in an attempt to avoid generating COPY
8643 // relocs.
8644 if (this->copy_relocs_.any_saved_relocs())
8645 this->copy_relocs_.emit(this->rel_dyn_section(layout));
8647 // Handle the .ARM.exidx section.
8648 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8650 if (!parameters->options().relocatable())
8652 if (exidx_section != NULL
8653 && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
8655 // Create __exidx_start and __exidx_end symbols.
8656 symtab->define_in_output_data("__exidx_start", NULL,
8657 Symbol_table::PREDEFINED,
8658 exidx_section, 0, 0, elfcpp::STT_OBJECT,
8659 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
8660 0, false, true);
8661 symtab->define_in_output_data("__exidx_end", NULL,
8662 Symbol_table::PREDEFINED,
8663 exidx_section, 0, 0, elfcpp::STT_OBJECT,
8664 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
8665 0, true, true);
8667 // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8668 // the .ARM.exidx section.
8669 if (!layout->script_options()->saw_phdrs_clause())
8671 gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
8673 == NULL);
8674 Output_segment* exidx_segment =
8675 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8676 exidx_segment->add_output_section_to_nonload(exidx_section,
8677 elfcpp::PF_R);
8680 else
8682 symtab->define_as_constant("__exidx_start", NULL,
8683 Symbol_table::PREDEFINED,
8684 0, 0, elfcpp::STT_OBJECT,
8685 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8686 true, false);
8687 symtab->define_as_constant("__exidx_end", NULL,
8688 Symbol_table::PREDEFINED,
8689 0, 0, elfcpp::STT_OBJECT,
8690 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8691 true, false);
8695 // Create an .ARM.attributes section if we have merged any attributes
8696 // from inputs.
8697 if (merged_any_attributes)
8699 Output_attributes_section_data* attributes_section =
8700 new Output_attributes_section_data(*this->attributes_section_data_);
8701 layout->add_output_section_data(".ARM.attributes",
8702 elfcpp::SHT_ARM_ATTRIBUTES, 0,
8703 attributes_section, ORDER_INVALID,
8704 false);
8707 // Fix up links in section EXIDX headers.
8708 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
8709 p != layout->section_list().end();
8710 ++p)
8711 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
8713 Arm_output_section<big_endian>* os =
8714 Arm_output_section<big_endian>::as_arm_output_section(*p);
8715 os->set_exidx_section_link();
8719 // Return whether a direct absolute static relocation needs to be applied.
8720 // In cases where Scan::local() or Scan::global() has created
8721 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8722 // of the relocation is carried in the data, and we must not
8723 // apply the static relocation.
8725 template<bool big_endian>
8726 inline bool
8727 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8728 const Sized_symbol<32>* gsym,
8729 unsigned int r_type,
8730 bool is_32bit,
8731 Output_section* output_section)
8733 // If the output section is not allocated, then we didn't call
8734 // scan_relocs, we didn't create a dynamic reloc, and we must apply
8735 // the reloc here.
8736 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8737 return true;
8739 int ref_flags = Scan::get_reference_flags(r_type);
8741 // For local symbols, we will have created a non-RELATIVE dynamic
8742 // relocation only if (a) the output is position independent,
8743 // (b) the relocation is absolute (not pc- or segment-relative), and
8744 // (c) the relocation is not 32 bits wide.
8745 if (gsym == NULL)
8746 return !(parameters->options().output_is_position_independent()
8747 && (ref_flags & Symbol::ABSOLUTE_REF)
8748 && !is_32bit);
8750 // For global symbols, we use the same helper routines used in the
8751 // scan pass. If we did not create a dynamic relocation, or if we
8752 // created a RELATIVE dynamic relocation, we should apply the static
8753 // relocation.
8754 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8755 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8756 && gsym->can_use_relative_reloc(ref_flags
8757 & Symbol::FUNCTION_CALL);
8758 return !has_dyn || is_rel;
8761 // Perform a relocation.
8763 template<bool big_endian>
8764 inline bool
8765 Target_arm<big_endian>::Relocate::relocate(
8766 const Relocate_info<32, big_endian>* relinfo,
8767 Target_arm* target,
8768 Output_section* output_section,
8769 size_t relnum,
8770 const elfcpp::Rel<32, big_endian>& rel,
8771 unsigned int r_type,
8772 const Sized_symbol<32>* gsym,
8773 const Symbol_value<32>* psymval,
8774 unsigned char* view,
8775 Arm_address address,
8776 section_size_type view_size)
8778 typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8780 r_type = get_real_reloc_type(r_type);
8781 const Arm_reloc_property* reloc_property =
8782 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8783 if (reloc_property == NULL)
8785 std::string reloc_name =
8786 arm_reloc_property_table->reloc_name_in_error_message(r_type);
8787 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8788 _("cannot relocate %s in object file"),
8789 reloc_name.c_str());
8790 return true;
8793 const Arm_relobj<big_endian>* object =
8794 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8796 // If the final branch target of a relocation is THUMB instruction, this
8797 // is 1. Otherwise it is 0.
8798 Arm_address thumb_bit = 0;
8799 Symbol_value<32> symval;
8800 bool is_weakly_undefined_without_plt = false;
8801 bool have_got_offset = false;
8802 unsigned int got_offset = 0;
8804 // If the relocation uses the GOT entry of a symbol instead of the symbol
8805 // itself, we don't care about whether the symbol is defined or what kind
8806 // of symbol it is.
8807 if (reloc_property->uses_got_entry())
8809 // Get the GOT offset.
8810 // The GOT pointer points to the end of the GOT section.
8811 // We need to subtract the size of the GOT section to get
8812 // the actual offset to use in the relocation.
8813 // TODO: We should move GOT offset computing code in TLS relocations
8814 // to here.
8815 switch (r_type)
8817 case elfcpp::R_ARM_GOT_BREL:
8818 case elfcpp::R_ARM_GOT_PREL:
8819 if (gsym != NULL)
8821 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8822 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8823 - target->got_size());
8825 else
8827 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8828 gold_assert(object->local_has_got_offset(r_sym,
8829 GOT_TYPE_STANDARD));
8830 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8831 - target->got_size());
8833 have_got_offset = true;
8834 break;
8836 default:
8837 break;
8840 else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8842 if (gsym != NULL)
8844 // This is a global symbol. Determine if we use PLT and if the
8845 // final target is THUMB.
8846 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
8848 // This uses a PLT, change the symbol value.
8849 symval.set_output_value(target->plt_section()->address()
8850 + gsym->plt_offset());
8851 psymval = &symval;
8853 else if (gsym->is_weak_undefined())
8855 // This is a weakly undefined symbol and we do not use PLT
8856 // for this relocation. A branch targeting this symbol will
8857 // be converted into an NOP.
8858 is_weakly_undefined_without_plt = true;
8860 else if (gsym->is_undefined() && reloc_property->uses_symbol())
8862 // This relocation uses the symbol value but the symbol is
8863 // undefined. Exit early and have the caller reporting an
8864 // error.
8865 return true;
8867 else
8869 // Set thumb bit if symbol:
8870 // -Has type STT_ARM_TFUNC or
8871 // -Has type STT_FUNC, is defined and with LSB in value set.
8872 thumb_bit =
8873 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8874 || (gsym->type() == elfcpp::STT_FUNC
8875 && !gsym->is_undefined()
8876 && ((psymval->value(object, 0) & 1) != 0)))
8878 : 0);
8881 else
8883 // This is a local symbol. Determine if the final target is THUMB.
8884 // We saved this information when all the local symbols were read.
8885 elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8886 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8887 thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8890 else
8892 // This is a fake relocation synthesized for a stub. It does not have
8893 // a real symbol. We just look at the LSB of the symbol value to
8894 // determine if the target is THUMB or not.
8895 thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8898 // Strip LSB if this points to a THUMB target.
8899 if (thumb_bit != 0
8900 && reloc_property->uses_thumb_bit()
8901 && ((psymval->value(object, 0) & 1) != 0))
8903 Arm_address stripped_value =
8904 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8905 symval.set_output_value(stripped_value);
8906 psymval = &symval;
8909 // To look up relocation stubs, we need to pass the symbol table index of
8910 // a local symbol.
8911 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8913 // Get the addressing origin of the output segment defining the
8914 // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8915 Arm_address sym_origin = 0;
8916 if (reloc_property->uses_symbol_base())
8918 if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8919 // R_ARM_BASE_ABS with the NULL symbol will give the
8920 // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8921 // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8922 sym_origin = target->got_plt_section()->address();
8923 else if (gsym == NULL)
8924 sym_origin = 0;
8925 else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8926 sym_origin = gsym->output_segment()->vaddr();
8927 else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
8928 sym_origin = gsym->output_data()->address();
8930 // TODO: Assumes the segment base to be zero for the global symbols
8931 // till the proper support for the segment-base-relative addressing
8932 // will be implemented. This is consistent with GNU ld.
8935 // For relative addressing relocation, find out the relative address base.
8936 Arm_address relative_address_base = 0;
8937 switch(reloc_property->relative_address_base())
8939 case Arm_reloc_property::RAB_NONE:
8940 // Relocations with relative address bases RAB_TLS and RAB_tp are
8941 // handled by relocate_tls. So we do not need to do anything here.
8942 case Arm_reloc_property::RAB_TLS:
8943 case Arm_reloc_property::RAB_tp:
8944 break;
8945 case Arm_reloc_property::RAB_B_S:
8946 relative_address_base = sym_origin;
8947 break;
8948 case Arm_reloc_property::RAB_GOT_ORG:
8949 relative_address_base = target->got_plt_section()->address();
8950 break;
8951 case Arm_reloc_property::RAB_P:
8952 relative_address_base = address;
8953 break;
8954 case Arm_reloc_property::RAB_Pa:
8955 relative_address_base = address & 0xfffffffcU;
8956 break;
8957 default:
8958 gold_unreachable();
8961 typename Arm_relocate_functions::Status reloc_status =
8962 Arm_relocate_functions::STATUS_OKAY;
8963 bool check_overflow = reloc_property->checks_overflow();
8964 switch (r_type)
8966 case elfcpp::R_ARM_NONE:
8967 break;
8969 case elfcpp::R_ARM_ABS8:
8970 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8971 reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
8972 break;
8974 case elfcpp::R_ARM_ABS12:
8975 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8976 reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
8977 break;
8979 case elfcpp::R_ARM_ABS16:
8980 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8981 reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
8982 break;
8984 case elfcpp::R_ARM_ABS32:
8985 if (should_apply_static_reloc(gsym, r_type, true, output_section))
8986 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8987 thumb_bit);
8988 break;
8990 case elfcpp::R_ARM_ABS32_NOI:
8991 if (should_apply_static_reloc(gsym, r_type, true, output_section))
8992 // No thumb bit for this relocation: (S + A)
8993 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8995 break;
8997 case elfcpp::R_ARM_MOVW_ABS_NC:
8998 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8999 reloc_status = Arm_relocate_functions::movw(view, object, psymval,
9000 0, thumb_bit,
9001 check_overflow);
9002 break;
9004 case elfcpp::R_ARM_MOVT_ABS:
9005 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9006 reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
9007 break;
9009 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9010 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9011 reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
9012 0, thumb_bit, false);
9013 break;
9015 case elfcpp::R_ARM_THM_MOVT_ABS:
9016 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9017 reloc_status = Arm_relocate_functions::thm_movt(view, object,
9018 psymval, 0);
9019 break;
9021 case elfcpp::R_ARM_MOVW_PREL_NC:
9022 case elfcpp::R_ARM_MOVW_BREL_NC:
9023 case elfcpp::R_ARM_MOVW_BREL:
9024 reloc_status =
9025 Arm_relocate_functions::movw(view, object, psymval,
9026 relative_address_base, thumb_bit,
9027 check_overflow);
9028 break;
9030 case elfcpp::R_ARM_MOVT_PREL:
9031 case elfcpp::R_ARM_MOVT_BREL:
9032 reloc_status =
9033 Arm_relocate_functions::movt(view, object, psymval,
9034 relative_address_base);
9035 break;
9037 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9038 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9039 case elfcpp::R_ARM_THM_MOVW_BREL:
9040 reloc_status =
9041 Arm_relocate_functions::thm_movw(view, object, psymval,
9042 relative_address_base,
9043 thumb_bit, check_overflow);
9044 break;
9046 case elfcpp::R_ARM_THM_MOVT_PREL:
9047 case elfcpp::R_ARM_THM_MOVT_BREL:
9048 reloc_status =
9049 Arm_relocate_functions::thm_movt(view, object, psymval,
9050 relative_address_base);
9051 break;
9053 case elfcpp::R_ARM_REL32:
9054 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9055 address, thumb_bit);
9056 break;
9058 case elfcpp::R_ARM_THM_ABS5:
9059 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9060 reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
9061 break;
9063 // Thumb long branches.
9064 case elfcpp::R_ARM_THM_CALL:
9065 case elfcpp::R_ARM_THM_XPC22:
9066 case elfcpp::R_ARM_THM_JUMP24:
9067 reloc_status =
9068 Arm_relocate_functions::thumb_branch_common(
9069 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9070 thumb_bit, is_weakly_undefined_without_plt);
9071 break;
9073 case elfcpp::R_ARM_GOTOFF32:
9075 Arm_address got_origin;
9076 got_origin = target->got_plt_section()->address();
9077 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9078 got_origin, thumb_bit);
9080 break;
9082 case elfcpp::R_ARM_BASE_PREL:
9083 gold_assert(gsym != NULL);
9084 reloc_status =
9085 Arm_relocate_functions::base_prel(view, sym_origin, address);
9086 break;
9088 case elfcpp::R_ARM_BASE_ABS:
9089 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9090 reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
9091 break;
9093 case elfcpp::R_ARM_GOT_BREL:
9094 gold_assert(have_got_offset);
9095 reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
9096 break;
9098 case elfcpp::R_ARM_GOT_PREL:
9099 gold_assert(have_got_offset);
9100 // Get the address origin for GOT PLT, which is allocated right
9101 // after the GOT section, to calculate an absolute address of
9102 // the symbol GOT entry (got_origin + got_offset).
9103 Arm_address got_origin;
9104 got_origin = target->got_plt_section()->address();
9105 reloc_status = Arm_relocate_functions::got_prel(view,
9106 got_origin + got_offset,
9107 address);
9108 break;
9110 case elfcpp::R_ARM_PLT32:
9111 case elfcpp::R_ARM_CALL:
9112 case elfcpp::R_ARM_JUMP24:
9113 case elfcpp::R_ARM_XPC25:
9114 gold_assert(gsym == NULL
9115 || gsym->has_plt_offset()
9116 || gsym->final_value_is_known()
9117 || (gsym->is_defined()
9118 && !gsym->is_from_dynobj()
9119 && !gsym->is_preemptible()));
9120 reloc_status =
9121 Arm_relocate_functions::arm_branch_common(
9122 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9123 thumb_bit, is_weakly_undefined_without_plt);
9124 break;
9126 case elfcpp::R_ARM_THM_JUMP19:
9127 reloc_status =
9128 Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9129 thumb_bit);
9130 break;
9132 case elfcpp::R_ARM_THM_JUMP6:
9133 reloc_status =
9134 Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9135 break;
9137 case elfcpp::R_ARM_THM_JUMP8:
9138 reloc_status =
9139 Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9140 break;
9142 case elfcpp::R_ARM_THM_JUMP11:
9143 reloc_status =
9144 Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9145 break;
9147 case elfcpp::R_ARM_PREL31:
9148 reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9149 address, thumb_bit);
9150 break;
9152 case elfcpp::R_ARM_V4BX:
9153 if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9155 const bool is_v4bx_interworking =
9156 (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9157 reloc_status =
9158 Arm_relocate_functions::v4bx(relinfo, view, object, address,
9159 is_v4bx_interworking);
9161 break;
9163 case elfcpp::R_ARM_THM_PC8:
9164 reloc_status =
9165 Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9166 break;
9168 case elfcpp::R_ARM_THM_PC12:
9169 reloc_status =
9170 Arm_relocate_functions::thm_pc12(view, object, psymval, address);
9171 break;
9173 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9174 reloc_status =
9175 Arm_relocate_functions::thm_alu11(view, object, psymval, address,
9176 thumb_bit);
9177 break;
9179 case elfcpp::R_ARM_ALU_PC_G0_NC:
9180 case elfcpp::R_ARM_ALU_PC_G0:
9181 case elfcpp::R_ARM_ALU_PC_G1_NC:
9182 case elfcpp::R_ARM_ALU_PC_G1:
9183 case elfcpp::R_ARM_ALU_PC_G2:
9184 case elfcpp::R_ARM_ALU_SB_G0_NC:
9185 case elfcpp::R_ARM_ALU_SB_G0:
9186 case elfcpp::R_ARM_ALU_SB_G1_NC:
9187 case elfcpp::R_ARM_ALU_SB_G1:
9188 case elfcpp::R_ARM_ALU_SB_G2:
9189 reloc_status =
9190 Arm_relocate_functions::arm_grp_alu(view, object, psymval,
9191 reloc_property->group_index(),
9192 relative_address_base,
9193 thumb_bit, check_overflow);
9194 break;
9196 case elfcpp::R_ARM_LDR_PC_G0:
9197 case elfcpp::R_ARM_LDR_PC_G1:
9198 case elfcpp::R_ARM_LDR_PC_G2:
9199 case elfcpp::R_ARM_LDR_SB_G0:
9200 case elfcpp::R_ARM_LDR_SB_G1:
9201 case elfcpp::R_ARM_LDR_SB_G2:
9202 reloc_status =
9203 Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9204 reloc_property->group_index(),
9205 relative_address_base);
9206 break;
9208 case elfcpp::R_ARM_LDRS_PC_G0:
9209 case elfcpp::R_ARM_LDRS_PC_G1:
9210 case elfcpp::R_ARM_LDRS_PC_G2:
9211 case elfcpp::R_ARM_LDRS_SB_G0:
9212 case elfcpp::R_ARM_LDRS_SB_G1:
9213 case elfcpp::R_ARM_LDRS_SB_G2:
9214 reloc_status =
9215 Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9216 reloc_property->group_index(),
9217 relative_address_base);
9218 break;
9220 case elfcpp::R_ARM_LDC_PC_G0:
9221 case elfcpp::R_ARM_LDC_PC_G1:
9222 case elfcpp::R_ARM_LDC_PC_G2:
9223 case elfcpp::R_ARM_LDC_SB_G0:
9224 case elfcpp::R_ARM_LDC_SB_G1:
9225 case elfcpp::R_ARM_LDC_SB_G2:
9226 reloc_status =
9227 Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9228 reloc_property->group_index(),
9229 relative_address_base);
9230 break;
9232 // These are initial tls relocs, which are expected when
9233 // linking.
9234 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9235 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9236 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9237 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9238 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9239 reloc_status =
9240 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9241 view, address, view_size);
9242 break;
9244 // The known and unknown unsupported and/or deprecated relocations.
9245 case elfcpp::R_ARM_PC24:
9246 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9247 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9248 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9249 default:
9250 // Just silently leave the method. We should get an appropriate error
9251 // message in the scan methods.
9252 break;
9255 // Report any errors.
9256 switch (reloc_status)
9258 case Arm_relocate_functions::STATUS_OKAY:
9259 break;
9260 case Arm_relocate_functions::STATUS_OVERFLOW:
9261 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9262 _("relocation overflow in %s"),
9263 reloc_property->name().c_str());
9264 break;
9265 case Arm_relocate_functions::STATUS_BAD_RELOC:
9266 gold_error_at_location(
9267 relinfo,
9268 relnum,
9269 rel.get_r_offset(),
9270 _("unexpected opcode while processing relocation %s"),
9271 reloc_property->name().c_str());
9272 break;
9273 default:
9274 gold_unreachable();
9277 return true;
9280 // Perform a TLS relocation.
9282 template<bool big_endian>
9283 inline typename Arm_relocate_functions<big_endian>::Status
9284 Target_arm<big_endian>::Relocate::relocate_tls(
9285 const Relocate_info<32, big_endian>* relinfo,
9286 Target_arm<big_endian>* target,
9287 size_t relnum,
9288 const elfcpp::Rel<32, big_endian>& rel,
9289 unsigned int r_type,
9290 const Sized_symbol<32>* gsym,
9291 const Symbol_value<32>* psymval,
9292 unsigned char* view,
9293 elfcpp::Elf_types<32>::Elf_Addr address,
9294 section_size_type /*view_size*/ )
9296 typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9297 typedef Relocate_functions<32, big_endian> RelocFuncs;
9298 Output_segment* tls_segment = relinfo->layout->tls_segment();
9300 const Sized_relobj_file<32, big_endian>* object = relinfo->object;
9302 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9304 const bool is_final = (gsym == NULL
9305 ? !parameters->options().shared()
9306 : gsym->final_value_is_known());
9307 const tls::Tls_optimization optimized_type
9308 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9309 switch (r_type)
9311 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9313 unsigned int got_type = GOT_TYPE_TLS_PAIR;
9314 unsigned int got_offset;
9315 if (gsym != NULL)
9317 gold_assert(gsym->has_got_offset(got_type));
9318 got_offset = gsym->got_offset(got_type) - target->got_size();
9320 else
9322 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9323 gold_assert(object->local_has_got_offset(r_sym, got_type));
9324 got_offset = (object->local_got_offset(r_sym, got_type)
9325 - target->got_size());
9327 if (optimized_type == tls::TLSOPT_NONE)
9329 Arm_address got_entry =
9330 target->got_plt_section()->address() + got_offset;
9332 // Relocate the field with the PC relative offset of the pair of
9333 // GOT entries.
9334 RelocFuncs::pcrel32(view, got_entry, address);
9335 return ArmRelocFuncs::STATUS_OKAY;
9338 break;
9340 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9341 if (optimized_type == tls::TLSOPT_NONE)
9343 // Relocate the field with the offset of the GOT entry for
9344 // the module index.
9345 unsigned int got_offset;
9346 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9347 - target->got_size());
9348 Arm_address got_entry =
9349 target->got_plt_section()->address() + got_offset;
9351 // Relocate the field with the PC relative offset of the pair of
9352 // GOT entries.
9353 RelocFuncs::pcrel32(view, got_entry, address);
9354 return ArmRelocFuncs::STATUS_OKAY;
9356 break;
9358 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9359 RelocFuncs::rel32(view, value);
9360 return ArmRelocFuncs::STATUS_OKAY;
9362 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9363 if (optimized_type == tls::TLSOPT_NONE)
9365 // Relocate the field with the offset of the GOT entry for
9366 // the tp-relative offset of the symbol.
9367 unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9368 unsigned int got_offset;
9369 if (gsym != NULL)
9371 gold_assert(gsym->has_got_offset(got_type));
9372 got_offset = gsym->got_offset(got_type);
9374 else
9376 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9377 gold_assert(object->local_has_got_offset(r_sym, got_type));
9378 got_offset = object->local_got_offset(r_sym, got_type);
9381 // All GOT offsets are relative to the end of the GOT.
9382 got_offset -= target->got_size();
9384 Arm_address got_entry =
9385 target->got_plt_section()->address() + got_offset;
9387 // Relocate the field with the PC relative offset of the GOT entry.
9388 RelocFuncs::pcrel32(view, got_entry, address);
9389 return ArmRelocFuncs::STATUS_OKAY;
9391 break;
9393 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9394 // If we're creating a shared library, a dynamic relocation will
9395 // have been created for this location, so do not apply it now.
9396 if (!parameters->options().shared())
9398 gold_assert(tls_segment != NULL);
9400 // $tp points to the TCB, which is followed by the TLS, so we
9401 // need to add TCB size to the offset.
9402 Arm_address aligned_tcb_size =
9403 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9404 RelocFuncs::rel32(view, value + aligned_tcb_size);
9407 return ArmRelocFuncs::STATUS_OKAY;
9409 default:
9410 gold_unreachable();
9413 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9414 _("unsupported reloc %u"),
9415 r_type);
9416 return ArmRelocFuncs::STATUS_BAD_RELOC;
9419 // Relocate section data.
9421 template<bool big_endian>
9422 void
9423 Target_arm<big_endian>::relocate_section(
9424 const Relocate_info<32, big_endian>* relinfo,
9425 unsigned int sh_type,
9426 const unsigned char* prelocs,
9427 size_t reloc_count,
9428 Output_section* output_section,
9429 bool needs_special_offset_handling,
9430 unsigned char* view,
9431 Arm_address address,
9432 section_size_type view_size,
9433 const Reloc_symbol_changes* reloc_symbol_changes)
9435 typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
9436 gold_assert(sh_type == elfcpp::SHT_REL);
9438 // See if we are relocating a relaxed input section. If so, the view
9439 // covers the whole output section and we need to adjust accordingly.
9440 if (needs_special_offset_handling)
9442 const Output_relaxed_input_section* poris =
9443 output_section->find_relaxed_input_section(relinfo->object,
9444 relinfo->data_shndx);
9445 if (poris != NULL)
9447 Arm_address section_address = poris->address();
9448 section_size_type section_size = poris->data_size();
9450 gold_assert((section_address >= address)
9451 && ((section_address + section_size)
9452 <= (address + view_size)));
9454 off_t offset = section_address - address;
9455 view += offset;
9456 address += offset;
9457 view_size = section_size;
9461 gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
9462 Arm_relocate>(
9463 relinfo,
9464 this,
9465 prelocs,
9466 reloc_count,
9467 output_section,
9468 needs_special_offset_handling,
9469 view,
9470 address,
9471 view_size,
9472 reloc_symbol_changes);
9475 // Return the size of a relocation while scanning during a relocatable
9476 // link.
9478 template<bool big_endian>
9479 unsigned int
9480 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
9481 unsigned int r_type,
9482 Relobj* object)
9484 r_type = get_real_reloc_type(r_type);
9485 const Arm_reloc_property* arp =
9486 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9487 if (arp != NULL)
9488 return arp->size();
9489 else
9491 std::string reloc_name =
9492 arm_reloc_property_table->reloc_name_in_error_message(r_type);
9493 gold_error(_("%s: unexpected %s in object file"),
9494 object->name().c_str(), reloc_name.c_str());
9495 return 0;
9499 // Scan the relocs during a relocatable link.
9501 template<bool big_endian>
9502 void
9503 Target_arm<big_endian>::scan_relocatable_relocs(
9504 Symbol_table* symtab,
9505 Layout* layout,
9506 Sized_relobj_file<32, big_endian>* object,
9507 unsigned int data_shndx,
9508 unsigned int sh_type,
9509 const unsigned char* prelocs,
9510 size_t reloc_count,
9511 Output_section* output_section,
9512 bool needs_special_offset_handling,
9513 size_t local_symbol_count,
9514 const unsigned char* plocal_symbols,
9515 Relocatable_relocs* rr)
9517 gold_assert(sh_type == elfcpp::SHT_REL);
9519 typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
9520 Relocatable_size_for_reloc> Scan_relocatable_relocs;
9522 gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
9523 Scan_relocatable_relocs>(
9524 symtab,
9525 layout,
9526 object,
9527 data_shndx,
9528 prelocs,
9529 reloc_count,
9530 output_section,
9531 needs_special_offset_handling,
9532 local_symbol_count,
9533 plocal_symbols,
9534 rr);
9537 // Relocate a section during a relocatable link.
9539 template<bool big_endian>
9540 void
9541 Target_arm<big_endian>::relocate_for_relocatable(
9542 const Relocate_info<32, big_endian>* relinfo,
9543 unsigned int sh_type,
9544 const unsigned char* prelocs,
9545 size_t reloc_count,
9546 Output_section* output_section,
9547 off_t offset_in_output_section,
9548 const Relocatable_relocs* rr,
9549 unsigned char* view,
9550 Arm_address view_address,
9551 section_size_type view_size,
9552 unsigned char* reloc_view,
9553 section_size_type reloc_view_size)
9555 gold_assert(sh_type == elfcpp::SHT_REL);
9557 gold::relocate_for_relocatable<32, big_endian, elfcpp::SHT_REL>(
9558 relinfo,
9559 prelocs,
9560 reloc_count,
9561 output_section,
9562 offset_in_output_section,
9564 view,
9565 view_address,
9566 view_size,
9567 reloc_view,
9568 reloc_view_size);
9571 // Perform target-specific processing in a relocatable link. This is
9572 // only used if we use the relocation strategy RELOC_SPECIAL.
9574 template<bool big_endian>
9575 void
9576 Target_arm<big_endian>::relocate_special_relocatable(
9577 const Relocate_info<32, big_endian>* relinfo,
9578 unsigned int sh_type,
9579 const unsigned char* preloc_in,
9580 size_t relnum,
9581 Output_section* output_section,
9582 off_t offset_in_output_section,
9583 unsigned char* view,
9584 elfcpp::Elf_types<32>::Elf_Addr view_address,
9585 section_size_type,
9586 unsigned char* preloc_out)
9588 // We can only handle REL type relocation sections.
9589 gold_assert(sh_type == elfcpp::SHT_REL);
9591 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
9592 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
9593 Reltype_write;
9594 const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
9596 const Arm_relobj<big_endian>* object =
9597 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9598 const unsigned int local_count = object->local_symbol_count();
9600 Reltype reloc(preloc_in);
9601 Reltype_write reloc_write(preloc_out);
9603 elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
9604 const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9605 const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
9607 const Arm_reloc_property* arp =
9608 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9609 gold_assert(arp != NULL);
9611 // Get the new symbol index.
9612 // We only use RELOC_SPECIAL strategy in local relocations.
9613 gold_assert(r_sym < local_count);
9615 // We are adjusting a section symbol. We need to find
9616 // the symbol table index of the section symbol for
9617 // the output section corresponding to input section
9618 // in which this symbol is defined.
9619 bool is_ordinary;
9620 unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
9621 gold_assert(is_ordinary);
9622 Output_section* os = object->output_section(shndx);
9623 gold_assert(os != NULL);
9624 gold_assert(os->needs_symtab_index());
9625 unsigned int new_symndx = os->symtab_index();
9627 // Get the new offset--the location in the output section where
9628 // this relocation should be applied.
9630 Arm_address offset = reloc.get_r_offset();
9631 Arm_address new_offset;
9632 if (offset_in_output_section != invalid_address)
9633 new_offset = offset + offset_in_output_section;
9634 else
9636 section_offset_type sot_offset =
9637 convert_types<section_offset_type, Arm_address>(offset);
9638 section_offset_type new_sot_offset =
9639 output_section->output_offset(object, relinfo->data_shndx,
9640 sot_offset);
9641 gold_assert(new_sot_offset != -1);
9642 new_offset = new_sot_offset;
9645 // In an object file, r_offset is an offset within the section.
9646 // In an executable or dynamic object, generated by
9647 // --emit-relocs, r_offset is an absolute address.
9648 if (!parameters->options().relocatable())
9650 new_offset += view_address;
9651 if (offset_in_output_section != invalid_address)
9652 new_offset -= offset_in_output_section;
9655 reloc_write.put_r_offset(new_offset);
9656 reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
9658 // Handle the reloc addend.
9659 // The relocation uses a section symbol in the input file.
9660 // We are adjusting it to use a section symbol in the output
9661 // file. The input section symbol refers to some address in
9662 // the input section. We need the relocation in the output
9663 // file to refer to that same address. This adjustment to
9664 // the addend is the same calculation we use for a simple
9665 // absolute relocation for the input section symbol.
9667 const Symbol_value<32>* psymval = object->local_symbol(r_sym);
9669 // Handle THUMB bit.
9670 Symbol_value<32> symval;
9671 Arm_address thumb_bit =
9672 object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9673 if (thumb_bit != 0
9674 && arp->uses_thumb_bit()
9675 && ((psymval->value(object, 0) & 1) != 0))
9677 Arm_address stripped_value =
9678 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9679 symval.set_output_value(stripped_value);
9680 psymval = &symval;
9683 unsigned char* paddend = view + offset;
9684 typename Arm_relocate_functions<big_endian>::Status reloc_status =
9685 Arm_relocate_functions<big_endian>::STATUS_OKAY;
9686 switch (r_type)
9688 case elfcpp::R_ARM_ABS8:
9689 reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
9690 psymval);
9691 break;
9693 case elfcpp::R_ARM_ABS12:
9694 reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
9695 psymval);
9696 break;
9698 case elfcpp::R_ARM_ABS16:
9699 reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
9700 psymval);
9701 break;
9703 case elfcpp::R_ARM_THM_ABS5:
9704 reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
9705 object,
9706 psymval);
9707 break;
9709 case elfcpp::R_ARM_MOVW_ABS_NC:
9710 case elfcpp::R_ARM_MOVW_PREL_NC:
9711 case elfcpp::R_ARM_MOVW_BREL_NC:
9712 case elfcpp::R_ARM_MOVW_BREL:
9713 reloc_status = Arm_relocate_functions<big_endian>::movw(
9714 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9715 break;
9717 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9718 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9719 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9720 case elfcpp::R_ARM_THM_MOVW_BREL:
9721 reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
9722 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9723 break;
9725 case elfcpp::R_ARM_THM_CALL:
9726 case elfcpp::R_ARM_THM_XPC22:
9727 case elfcpp::R_ARM_THM_JUMP24:
9728 reloc_status =
9729 Arm_relocate_functions<big_endian>::thumb_branch_common(
9730 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9731 false);
9732 break;
9734 case elfcpp::R_ARM_PLT32:
9735 case elfcpp::R_ARM_CALL:
9736 case elfcpp::R_ARM_JUMP24:
9737 case elfcpp::R_ARM_XPC25:
9738 reloc_status =
9739 Arm_relocate_functions<big_endian>::arm_branch_common(
9740 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9741 false);
9742 break;
9744 case elfcpp::R_ARM_THM_JUMP19:
9745 reloc_status =
9746 Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
9747 psymval, 0, thumb_bit);
9748 break;
9750 case elfcpp::R_ARM_THM_JUMP6:
9751 reloc_status =
9752 Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
9754 break;
9756 case elfcpp::R_ARM_THM_JUMP8:
9757 reloc_status =
9758 Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
9760 break;
9762 case elfcpp::R_ARM_THM_JUMP11:
9763 reloc_status =
9764 Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
9766 break;
9768 case elfcpp::R_ARM_PREL31:
9769 reloc_status =
9770 Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
9771 thumb_bit);
9772 break;
9774 case elfcpp::R_ARM_THM_PC8:
9775 reloc_status =
9776 Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
9778 break;
9780 case elfcpp::R_ARM_THM_PC12:
9781 reloc_status =
9782 Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
9784 break;
9786 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9787 reloc_status =
9788 Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
9789 0, thumb_bit);
9790 break;
9792 // These relocation truncate relocation results so we cannot handle them
9793 // in a relocatable link.
9794 case elfcpp::R_ARM_MOVT_ABS:
9795 case elfcpp::R_ARM_THM_MOVT_ABS:
9796 case elfcpp::R_ARM_MOVT_PREL:
9797 case elfcpp::R_ARM_MOVT_BREL:
9798 case elfcpp::R_ARM_THM_MOVT_PREL:
9799 case elfcpp::R_ARM_THM_MOVT_BREL:
9800 case elfcpp::R_ARM_ALU_PC_G0_NC:
9801 case elfcpp::R_ARM_ALU_PC_G0:
9802 case elfcpp::R_ARM_ALU_PC_G1_NC:
9803 case elfcpp::R_ARM_ALU_PC_G1:
9804 case elfcpp::R_ARM_ALU_PC_G2:
9805 case elfcpp::R_ARM_ALU_SB_G0_NC:
9806 case elfcpp::R_ARM_ALU_SB_G0:
9807 case elfcpp::R_ARM_ALU_SB_G1_NC:
9808 case elfcpp::R_ARM_ALU_SB_G1:
9809 case elfcpp::R_ARM_ALU_SB_G2:
9810 case elfcpp::R_ARM_LDR_PC_G0:
9811 case elfcpp::R_ARM_LDR_PC_G1:
9812 case elfcpp::R_ARM_LDR_PC_G2:
9813 case elfcpp::R_ARM_LDR_SB_G0:
9814 case elfcpp::R_ARM_LDR_SB_G1:
9815 case elfcpp::R_ARM_LDR_SB_G2:
9816 case elfcpp::R_ARM_LDRS_PC_G0:
9817 case elfcpp::R_ARM_LDRS_PC_G1:
9818 case elfcpp::R_ARM_LDRS_PC_G2:
9819 case elfcpp::R_ARM_LDRS_SB_G0:
9820 case elfcpp::R_ARM_LDRS_SB_G1:
9821 case elfcpp::R_ARM_LDRS_SB_G2:
9822 case elfcpp::R_ARM_LDC_PC_G0:
9823 case elfcpp::R_ARM_LDC_PC_G1:
9824 case elfcpp::R_ARM_LDC_PC_G2:
9825 case elfcpp::R_ARM_LDC_SB_G0:
9826 case elfcpp::R_ARM_LDC_SB_G1:
9827 case elfcpp::R_ARM_LDC_SB_G2:
9828 gold_error(_("cannot handle %s in a relocatable link"),
9829 arp->name().c_str());
9830 break;
9832 default:
9833 gold_unreachable();
9836 // Report any errors.
9837 switch (reloc_status)
9839 case Arm_relocate_functions<big_endian>::STATUS_OKAY:
9840 break;
9841 case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
9842 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9843 _("relocation overflow in %s"),
9844 arp->name().c_str());
9845 break;
9846 case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
9847 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9848 _("unexpected opcode while processing relocation %s"),
9849 arp->name().c_str());
9850 break;
9851 default:
9852 gold_unreachable();
9856 // Return the value to use for a dynamic symbol which requires special
9857 // treatment. This is how we support equality comparisons of function
9858 // pointers across shared library boundaries, as described in the
9859 // processor specific ABI supplement.
9861 template<bool big_endian>
9862 uint64_t
9863 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
9865 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
9866 return this->plt_section()->address() + gsym->plt_offset();
9869 // Map platform-specific relocs to real relocs
9871 template<bool big_endian>
9872 unsigned int
9873 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
9875 switch (r_type)
9877 case elfcpp::R_ARM_TARGET1:
9878 // This is either R_ARM_ABS32 or R_ARM_REL32;
9879 return elfcpp::R_ARM_ABS32;
9881 case elfcpp::R_ARM_TARGET2:
9882 // This can be any reloc type but usually is R_ARM_GOT_PREL
9883 return elfcpp::R_ARM_GOT_PREL;
9885 default:
9886 return r_type;
9890 // Whether if two EABI versions V1 and V2 are compatible.
9892 template<bool big_endian>
9893 bool
9894 Target_arm<big_endian>::are_eabi_versions_compatible(
9895 elfcpp::Elf_Word v1,
9896 elfcpp::Elf_Word v2)
9898 // v4 and v5 are the same spec before and after it was released,
9899 // so allow mixing them.
9900 if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
9901 || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
9902 || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
9903 return true;
9905 return v1 == v2;
9908 // Combine FLAGS from an input object called NAME and the processor-specific
9909 // flags in the ELF header of the output. Much of this is adapted from the
9910 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
9911 // in bfd/elf32-arm.c.
9913 template<bool big_endian>
9914 void
9915 Target_arm<big_endian>::merge_processor_specific_flags(
9916 const std::string& name,
9917 elfcpp::Elf_Word flags)
9919 if (this->are_processor_specific_flags_set())
9921 elfcpp::Elf_Word out_flags = this->processor_specific_flags();
9923 // Nothing to merge if flags equal to those in output.
9924 if (flags == out_flags)
9925 return;
9927 // Complain about various flag mismatches.
9928 elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
9929 elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
9930 if (!this->are_eabi_versions_compatible(version1, version2)
9931 && parameters->options().warn_mismatch())
9932 gold_error(_("Source object %s has EABI version %d but output has "
9933 "EABI version %d."),
9934 name.c_str(),
9935 (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
9936 (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
9938 else
9940 // If the input is the default architecture and had the default
9941 // flags then do not bother setting the flags for the output
9942 // architecture, instead allow future merges to do this. If no
9943 // future merges ever set these flags then they will retain their
9944 // uninitialised values, which surprise surprise, correspond
9945 // to the default values.
9946 if (flags == 0)
9947 return;
9949 // This is the first time, just copy the flags.
9950 // We only copy the EABI version for now.
9951 this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
9955 // Adjust ELF file header.
9956 template<bool big_endian>
9957 void
9958 Target_arm<big_endian>::do_adjust_elf_header(
9959 unsigned char* view,
9960 int len) const
9962 gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
9964 elfcpp::Ehdr<32, big_endian> ehdr(view);
9965 unsigned char e_ident[elfcpp::EI_NIDENT];
9966 memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
9968 if (elfcpp::arm_eabi_version(this->processor_specific_flags())
9969 == elfcpp::EF_ARM_EABI_UNKNOWN)
9970 e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
9971 else
9972 e_ident[elfcpp::EI_OSABI] = 0;
9973 e_ident[elfcpp::EI_ABIVERSION] = 0;
9975 // FIXME: Do EF_ARM_BE8 adjustment.
9977 elfcpp::Ehdr_write<32, big_endian> oehdr(view);
9978 oehdr.put_e_ident(e_ident);
9981 // do_make_elf_object to override the same function in the base class.
9982 // We need to use a target-specific sub-class of
9983 // Sized_relobj_file<32, big_endian> to store ARM specific information.
9984 // Hence we need to have our own ELF object creation.
9986 template<bool big_endian>
9987 Object*
9988 Target_arm<big_endian>::do_make_elf_object(
9989 const std::string& name,
9990 Input_file* input_file,
9991 off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
9993 int et = ehdr.get_e_type();
9994 if (et == elfcpp::ET_REL)
9996 Arm_relobj<big_endian>* obj =
9997 new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
9998 obj->setup();
9999 return obj;
10001 else if (et == elfcpp::ET_DYN)
10003 Sized_dynobj<32, big_endian>* obj =
10004 new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
10005 obj->setup();
10006 return obj;
10008 else
10010 gold_error(_("%s: unsupported ELF file type %d"),
10011 name.c_str(), et);
10012 return NULL;
10016 // Read the architecture from the Tag_also_compatible_with attribute, if any.
10017 // Returns -1 if no architecture could be read.
10018 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
10020 template<bool big_endian>
10022 Target_arm<big_endian>::get_secondary_compatible_arch(
10023 const Attributes_section_data* pasd)
10025 const Object_attribute* known_attributes =
10026 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10028 // Note: the tag and its argument below are uleb128 values, though
10029 // currently-defined values fit in one byte for each.
10030 const std::string& sv =
10031 known_attributes[elfcpp::Tag_also_compatible_with].string_value();
10032 if (sv.size() == 2
10033 && sv.data()[0] == elfcpp::Tag_CPU_arch
10034 && (sv.data()[1] & 128) != 128)
10035 return sv.data()[1];
10037 // This tag is "safely ignorable", so don't complain if it looks funny.
10038 return -1;
10041 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10042 // The tag is removed if ARCH is -1.
10043 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10045 template<bool big_endian>
10046 void
10047 Target_arm<big_endian>::set_secondary_compatible_arch(
10048 Attributes_section_data* pasd,
10049 int arch)
10051 Object_attribute* known_attributes =
10052 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10054 if (arch == -1)
10056 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10057 return;
10060 // Note: the tag and its argument below are uleb128 values, though
10061 // currently-defined values fit in one byte for each.
10062 char sv[3];
10063 sv[0] = elfcpp::Tag_CPU_arch;
10064 gold_assert(arch != 0);
10065 sv[1] = arch;
10066 sv[2] = '\0';
10068 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10071 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10072 // into account.
10073 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10075 template<bool big_endian>
10077 Target_arm<big_endian>::tag_cpu_arch_combine(
10078 const char* name,
10079 int oldtag,
10080 int* secondary_compat_out,
10081 int newtag,
10082 int secondary_compat)
10084 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10085 static const int v6t2[] =
10087 T(V6T2), // PRE_V4.
10088 T(V6T2), // V4.
10089 T(V6T2), // V4T.
10090 T(V6T2), // V5T.
10091 T(V6T2), // V5TE.
10092 T(V6T2), // V5TEJ.
10093 T(V6T2), // V6.
10094 T(V7), // V6KZ.
10095 T(V6T2) // V6T2.
10097 static const int v6k[] =
10099 T(V6K), // PRE_V4.
10100 T(V6K), // V4.
10101 T(V6K), // V4T.
10102 T(V6K), // V5T.
10103 T(V6K), // V5TE.
10104 T(V6K), // V5TEJ.
10105 T(V6K), // V6.
10106 T(V6KZ), // V6KZ.
10107 T(V7), // V6T2.
10108 T(V6K) // V6K.
10110 static const int v7[] =
10112 T(V7), // PRE_V4.
10113 T(V7), // V4.
10114 T(V7), // V4T.
10115 T(V7), // V5T.
10116 T(V7), // V5TE.
10117 T(V7), // V5TEJ.
10118 T(V7), // V6.
10119 T(V7), // V6KZ.
10120 T(V7), // V6T2.
10121 T(V7), // V6K.
10122 T(V7) // V7.
10124 static const int v6_m[] =
10126 -1, // PRE_V4.
10127 -1, // V4.
10128 T(V6K), // V4T.
10129 T(V6K), // V5T.
10130 T(V6K), // V5TE.
10131 T(V6K), // V5TEJ.
10132 T(V6K), // V6.
10133 T(V6KZ), // V6KZ.
10134 T(V7), // V6T2.
10135 T(V6K), // V6K.
10136 T(V7), // V7.
10137 T(V6_M) // V6_M.
10139 static const int v6s_m[] =
10141 -1, // PRE_V4.
10142 -1, // V4.
10143 T(V6K), // V4T.
10144 T(V6K), // V5T.
10145 T(V6K), // V5TE.
10146 T(V6K), // V5TEJ.
10147 T(V6K), // V6.
10148 T(V6KZ), // V6KZ.
10149 T(V7), // V6T2.
10150 T(V6K), // V6K.
10151 T(V7), // V7.
10152 T(V6S_M), // V6_M.
10153 T(V6S_M) // V6S_M.
10155 static const int v7e_m[] =
10157 -1, // PRE_V4.
10158 -1, // V4.
10159 T(V7E_M), // V4T.
10160 T(V7E_M), // V5T.
10161 T(V7E_M), // V5TE.
10162 T(V7E_M), // V5TEJ.
10163 T(V7E_M), // V6.
10164 T(V7E_M), // V6KZ.
10165 T(V7E_M), // V6T2.
10166 T(V7E_M), // V6K.
10167 T(V7E_M), // V7.
10168 T(V7E_M), // V6_M.
10169 T(V7E_M), // V6S_M.
10170 T(V7E_M) // V7E_M.
10172 static const int v4t_plus_v6_m[] =
10174 -1, // PRE_V4.
10175 -1, // V4.
10176 T(V4T), // V4T.
10177 T(V5T), // V5T.
10178 T(V5TE), // V5TE.
10179 T(V5TEJ), // V5TEJ.
10180 T(V6), // V6.
10181 T(V6KZ), // V6KZ.
10182 T(V6T2), // V6T2.
10183 T(V6K), // V6K.
10184 T(V7), // V7.
10185 T(V6_M), // V6_M.
10186 T(V6S_M), // V6S_M.
10187 T(V7E_M), // V7E_M.
10188 T(V4T_PLUS_V6_M) // V4T plus V6_M.
10190 static const int* comb[] =
10192 v6t2,
10193 v6k,
10195 v6_m,
10196 v6s_m,
10197 v7e_m,
10198 // Pseudo-architecture.
10199 v4t_plus_v6_m
10202 // Check we've not got a higher architecture than we know about.
10204 if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
10206 gold_error(_("%s: unknown CPU architecture"), name);
10207 return -1;
10210 // Override old tag if we have a Tag_also_compatible_with on the output.
10212 if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10213 || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10214 oldtag = T(V4T_PLUS_V6_M);
10216 // And override the new tag if we have a Tag_also_compatible_with on the
10217 // input.
10219 if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10220 || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10221 newtag = T(V4T_PLUS_V6_M);
10223 // Architectures before V6KZ add features monotonically.
10224 int tagh = std::max(oldtag, newtag);
10225 if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10226 return tagh;
10228 int tagl = std::min(oldtag, newtag);
10229 int result = comb[tagh - T(V6T2)][tagl];
10231 // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10232 // as the canonical version.
10233 if (result == T(V4T_PLUS_V6_M))
10235 result = T(V4T);
10236 *secondary_compat_out = T(V6_M);
10238 else
10239 *secondary_compat_out = -1;
10241 if (result == -1)
10243 gold_error(_("%s: conflicting CPU architectures %d/%d"),
10244 name, oldtag, newtag);
10245 return -1;
10248 return result;
10249 #undef T
10252 // Helper to print AEABI enum tag value.
10254 template<bool big_endian>
10255 std::string
10256 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10258 static const char* aeabi_enum_names[] =
10259 { "", "variable-size", "32-bit", "" };
10260 const size_t aeabi_enum_names_size =
10261 sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10263 if (value < aeabi_enum_names_size)
10264 return std::string(aeabi_enum_names[value]);
10265 else
10267 char buffer[100];
10268 sprintf(buffer, "<unknown value %u>", value);
10269 return std::string(buffer);
10273 // Return the string value to store in TAG_CPU_name.
10275 template<bool big_endian>
10276 std::string
10277 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10279 static const char* name_table[] = {
10280 // These aren't real CPU names, but we can't guess
10281 // that from the architecture version alone.
10282 "Pre v4",
10283 "ARM v4",
10284 "ARM v4T",
10285 "ARM v5T",
10286 "ARM v5TE",
10287 "ARM v5TEJ",
10288 "ARM v6",
10289 "ARM v6KZ",
10290 "ARM v6T2",
10291 "ARM v6K",
10292 "ARM v7",
10293 "ARM v6-M",
10294 "ARM v6S-M",
10295 "ARM v7E-M"
10297 const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10299 if (value < name_table_size)
10300 return std::string(name_table[value]);
10301 else
10303 char buffer[100];
10304 sprintf(buffer, "<unknown CPU value %u>", value);
10305 return std::string(buffer);
10309 // Merge object attributes from input file called NAME with those of the
10310 // output. The input object attributes are in the object pointed by PASD.
10312 template<bool big_endian>
10313 void
10314 Target_arm<big_endian>::merge_object_attributes(
10315 const char* name,
10316 const Attributes_section_data* pasd)
10318 // Return if there is no attributes section data.
10319 if (pasd == NULL)
10320 return;
10322 // If output has no object attributes, just copy.
10323 const int vendor = Object_attribute::OBJ_ATTR_PROC;
10324 if (this->attributes_section_data_ == NULL)
10326 this->attributes_section_data_ = new Attributes_section_data(*pasd);
10327 Object_attribute* out_attr =
10328 this->attributes_section_data_->known_attributes(vendor);
10330 // We do not output objects with Tag_MPextension_use_legacy - we move
10331 // the attribute's value to Tag_MPextension_use. */
10332 if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10334 if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10335 && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10336 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10338 gold_error(_("%s has both the current and legacy "
10339 "Tag_MPextension_use attributes"),
10340 name);
10343 out_attr[elfcpp::Tag_MPextension_use] =
10344 out_attr[elfcpp::Tag_MPextension_use_legacy];
10345 out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10346 out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10349 return;
10352 const Object_attribute* in_attr = pasd->known_attributes(vendor);
10353 Object_attribute* out_attr =
10354 this->attributes_section_data_->known_attributes(vendor);
10356 // This needs to happen before Tag_ABI_FP_number_model is merged. */
10357 if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10358 != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
10360 // Ignore mismatches if the object doesn't use floating point. */
10361 if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
10362 out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10363 in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10364 else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
10365 && parameters->options().warn_mismatch())
10366 gold_error(_("%s uses VFP register arguments, output does not"),
10367 name);
10370 for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10372 // Merge this attribute with existing attributes.
10373 switch (i)
10375 case elfcpp::Tag_CPU_raw_name:
10376 case elfcpp::Tag_CPU_name:
10377 // These are merged after Tag_CPU_arch.
10378 break;
10380 case elfcpp::Tag_ABI_optimization_goals:
10381 case elfcpp::Tag_ABI_FP_optimization_goals:
10382 // Use the first value seen.
10383 break;
10385 case elfcpp::Tag_CPU_arch:
10387 unsigned int saved_out_attr = out_attr->int_value();
10388 // Merge Tag_CPU_arch and Tag_also_compatible_with.
10389 int secondary_compat =
10390 this->get_secondary_compatible_arch(pasd);
10391 int secondary_compat_out =
10392 this->get_secondary_compatible_arch(
10393 this->attributes_section_data_);
10394 out_attr[i].set_int_value(
10395 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10396 &secondary_compat_out,
10397 in_attr[i].int_value(),
10398 secondary_compat));
10399 this->set_secondary_compatible_arch(this->attributes_section_data_,
10400 secondary_compat_out);
10402 // Merge Tag_CPU_name and Tag_CPU_raw_name.
10403 if (out_attr[i].int_value() == saved_out_attr)
10404 ; // Leave the names alone.
10405 else if (out_attr[i].int_value() == in_attr[i].int_value())
10407 // The output architecture has been changed to match the
10408 // input architecture. Use the input names.
10409 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10410 in_attr[elfcpp::Tag_CPU_name].string_value());
10411 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10412 in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10414 else
10416 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10417 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10420 // If we still don't have a value for Tag_CPU_name,
10421 // make one up now. Tag_CPU_raw_name remains blank.
10422 if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10424 const std::string cpu_name =
10425 this->tag_cpu_name_value(out_attr[i].int_value());
10426 // FIXME: If we see an unknown CPU, this will be set
10427 // to "<unknown CPU n>", where n is the attribute value.
10428 // This is different from BFD, which leaves the name alone.
10429 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10432 break;
10434 case elfcpp::Tag_ARM_ISA_use:
10435 case elfcpp::Tag_THUMB_ISA_use:
10436 case elfcpp::Tag_WMMX_arch:
10437 case elfcpp::Tag_Advanced_SIMD_arch:
10438 // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10439 case elfcpp::Tag_ABI_FP_rounding:
10440 case elfcpp::Tag_ABI_FP_exceptions:
10441 case elfcpp::Tag_ABI_FP_user_exceptions:
10442 case elfcpp::Tag_ABI_FP_number_model:
10443 case elfcpp::Tag_VFP_HP_extension:
10444 case elfcpp::Tag_CPU_unaligned_access:
10445 case elfcpp::Tag_T2EE_use:
10446 case elfcpp::Tag_Virtualization_use:
10447 case elfcpp::Tag_MPextension_use:
10448 // Use the largest value specified.
10449 if (in_attr[i].int_value() > out_attr[i].int_value())
10450 out_attr[i].set_int_value(in_attr[i].int_value());
10451 break;
10453 case elfcpp::Tag_ABI_align8_preserved:
10454 case elfcpp::Tag_ABI_PCS_RO_data:
10455 // Use the smallest value specified.
10456 if (in_attr[i].int_value() < out_attr[i].int_value())
10457 out_attr[i].set_int_value(in_attr[i].int_value());
10458 break;
10460 case elfcpp::Tag_ABI_align8_needed:
10461 if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10462 && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10463 || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10464 == 0)))
10466 // This error message should be enabled once all non-conforming
10467 // binaries in the toolchain have had the attributes set
10468 // properly.
10469 // gold_error(_("output 8-byte data alignment conflicts with %s"),
10470 // name);
10472 // Fall through.
10473 case elfcpp::Tag_ABI_FP_denormal:
10474 case elfcpp::Tag_ABI_PCS_GOT_use:
10476 // These tags have 0 = don't care, 1 = strong requirement,
10477 // 2 = weak requirement.
10478 static const int order_021[3] = {0, 2, 1};
10480 // Use the "greatest" from the sequence 0, 2, 1, or the largest
10481 // value if greater than 2 (for future-proofing).
10482 if ((in_attr[i].int_value() > 2
10483 && in_attr[i].int_value() > out_attr[i].int_value())
10484 || (in_attr[i].int_value() <= 2
10485 && out_attr[i].int_value() <= 2
10486 && (order_021[in_attr[i].int_value()]
10487 > order_021[out_attr[i].int_value()])))
10488 out_attr[i].set_int_value(in_attr[i].int_value());
10490 break;
10492 case elfcpp::Tag_CPU_arch_profile:
10493 if (out_attr[i].int_value() != in_attr[i].int_value())
10495 // 0 will merge with anything.
10496 // 'A' and 'S' merge to 'A'.
10497 // 'R' and 'S' merge to 'R'.
10498 // 'M' and 'A|R|S' is an error.
10499 if (out_attr[i].int_value() == 0
10500 || (out_attr[i].int_value() == 'S'
10501 && (in_attr[i].int_value() == 'A'
10502 || in_attr[i].int_value() == 'R')))
10503 out_attr[i].set_int_value(in_attr[i].int_value());
10504 else if (in_attr[i].int_value() == 0
10505 || (in_attr[i].int_value() == 'S'
10506 && (out_attr[i].int_value() == 'A'
10507 || out_attr[i].int_value() == 'R')))
10508 ; // Do nothing.
10509 else if (parameters->options().warn_mismatch())
10511 gold_error
10512 (_("conflicting architecture profiles %c/%c"),
10513 in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10514 out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10517 break;
10518 case elfcpp::Tag_VFP_arch:
10520 static const struct
10522 int ver;
10523 int regs;
10524 } vfp_versions[7] =
10526 {0, 0},
10527 {1, 16},
10528 {2, 16},
10529 {3, 32},
10530 {3, 16},
10531 {4, 32},
10532 {4, 16}
10535 // Values greater than 6 aren't defined, so just pick the
10536 // biggest.
10537 if (in_attr[i].int_value() > 6
10538 && in_attr[i].int_value() > out_attr[i].int_value())
10540 *out_attr = *in_attr;
10541 break;
10543 // The output uses the superset of input features
10544 // (ISA version) and registers.
10545 int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10546 vfp_versions[out_attr[i].int_value()].ver);
10547 int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10548 vfp_versions[out_attr[i].int_value()].regs);
10549 // This assumes all possible supersets are also a valid
10550 // options.
10551 int newval;
10552 for (newval = 6; newval > 0; newval--)
10554 if (regs == vfp_versions[newval].regs
10555 && ver == vfp_versions[newval].ver)
10556 break;
10558 out_attr[i].set_int_value(newval);
10560 break;
10561 case elfcpp::Tag_PCS_config:
10562 if (out_attr[i].int_value() == 0)
10563 out_attr[i].set_int_value(in_attr[i].int_value());
10564 else if (in_attr[i].int_value() != 0
10565 && out_attr[i].int_value() != 0
10566 && parameters->options().warn_mismatch())
10568 // It's sometimes ok to mix different configs, so this is only
10569 // a warning.
10570 gold_warning(_("%s: conflicting platform configuration"), name);
10572 break;
10573 case elfcpp::Tag_ABI_PCS_R9_use:
10574 if (in_attr[i].int_value() != out_attr[i].int_value()
10575 && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10576 && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10577 && parameters->options().warn_mismatch())
10579 gold_error(_("%s: conflicting use of R9"), name);
10581 if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10582 out_attr[i].set_int_value(in_attr[i].int_value());
10583 break;
10584 case elfcpp::Tag_ABI_PCS_RW_data:
10585 if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10586 && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10587 != elfcpp::AEABI_R9_SB)
10588 && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10589 != elfcpp::AEABI_R9_unused)
10590 && parameters->options().warn_mismatch())
10592 gold_error(_("%s: SB relative addressing conflicts with use "
10593 "of R9"),
10594 name);
10596 // Use the smallest value specified.
10597 if (in_attr[i].int_value() < out_attr[i].int_value())
10598 out_attr[i].set_int_value(in_attr[i].int_value());
10599 break;
10600 case elfcpp::Tag_ABI_PCS_wchar_t:
10601 if (out_attr[i].int_value()
10602 && in_attr[i].int_value()
10603 && out_attr[i].int_value() != in_attr[i].int_value()
10604 && parameters->options().warn_mismatch()
10605 && parameters->options().wchar_size_warning())
10607 gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10608 "use %u-byte wchar_t; use of wchar_t values "
10609 "across objects may fail"),
10610 name, in_attr[i].int_value(),
10611 out_attr[i].int_value());
10613 else if (in_attr[i].int_value() && !out_attr[i].int_value())
10614 out_attr[i].set_int_value(in_attr[i].int_value());
10615 break;
10616 case elfcpp::Tag_ABI_enum_size:
10617 if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10619 if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10620 || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10622 // The existing object is compatible with anything.
10623 // Use whatever requirements the new object has.
10624 out_attr[i].set_int_value(in_attr[i].int_value());
10626 else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10627 && out_attr[i].int_value() != in_attr[i].int_value()
10628 && parameters->options().warn_mismatch()
10629 && parameters->options().enum_size_warning())
10631 unsigned int in_value = in_attr[i].int_value();
10632 unsigned int out_value = out_attr[i].int_value();
10633 gold_warning(_("%s uses %s enums yet the output is to use "
10634 "%s enums; use of enum values across objects "
10635 "may fail"),
10636 name,
10637 this->aeabi_enum_name(in_value).c_str(),
10638 this->aeabi_enum_name(out_value).c_str());
10641 break;
10642 case elfcpp::Tag_ABI_VFP_args:
10643 // Already done.
10644 break;
10645 case elfcpp::Tag_ABI_WMMX_args:
10646 if (in_attr[i].int_value() != out_attr[i].int_value()
10647 && parameters->options().warn_mismatch())
10649 gold_error(_("%s uses iWMMXt register arguments, output does "
10650 "not"),
10651 name);
10653 break;
10654 case Object_attribute::Tag_compatibility:
10655 // Merged in target-independent code.
10656 break;
10657 case elfcpp::Tag_ABI_HardFP_use:
10658 // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10659 if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10660 || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10661 out_attr[i].set_int_value(3);
10662 else if (in_attr[i].int_value() > out_attr[i].int_value())
10663 out_attr[i].set_int_value(in_attr[i].int_value());
10664 break;
10665 case elfcpp::Tag_ABI_FP_16bit_format:
10666 if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10668 if (in_attr[i].int_value() != out_attr[i].int_value()
10669 && parameters->options().warn_mismatch())
10670 gold_error(_("fp16 format mismatch between %s and output"),
10671 name);
10673 if (in_attr[i].int_value() != 0)
10674 out_attr[i].set_int_value(in_attr[i].int_value());
10675 break;
10677 case elfcpp::Tag_DIV_use:
10678 // This tag is set to zero if we can use UDIV and SDIV in Thumb
10679 // mode on a v7-M or v7-R CPU; to one if we can not use UDIV or
10680 // SDIV at all; and to two if we can use UDIV or SDIV on a v7-A
10681 // CPU. We will merge as follows: If the input attribute's value
10682 // is one then the output attribute's value remains unchanged. If
10683 // the input attribute's value is zero or two then if the output
10684 // attribute's value is one the output value is set to the input
10685 // value, otherwise the output value must be the same as the
10686 // inputs. */
10687 if (in_attr[i].int_value() != 1 && out_attr[i].int_value() != 1)
10689 if (in_attr[i].int_value() != out_attr[i].int_value())
10691 gold_error(_("DIV usage mismatch between %s and output"),
10692 name);
10696 if (in_attr[i].int_value() != 1)
10697 out_attr[i].set_int_value(in_attr[i].int_value());
10699 break;
10701 case elfcpp::Tag_MPextension_use_legacy:
10702 // We don't output objects with Tag_MPextension_use_legacy - we
10703 // move the value to Tag_MPextension_use.
10704 if (in_attr[i].int_value() != 0
10705 && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10707 if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10708 != in_attr[i].int_value())
10710 gold_error(_("%s has has both the current and legacy "
10711 "Tag_MPextension_use attributes"),
10712 name);
10716 if (in_attr[i].int_value()
10717 > out_attr[elfcpp::Tag_MPextension_use].int_value())
10718 out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10720 break;
10722 case elfcpp::Tag_nodefaults:
10723 // This tag is set if it exists, but the value is unused (and is
10724 // typically zero). We don't actually need to do anything here -
10725 // the merge happens automatically when the type flags are merged
10726 // below.
10727 break;
10728 case elfcpp::Tag_also_compatible_with:
10729 // Already done in Tag_CPU_arch.
10730 break;
10731 case elfcpp::Tag_conformance:
10732 // Keep the attribute if it matches. Throw it away otherwise.
10733 // No attribute means no claim to conform.
10734 if (in_attr[i].string_value() != out_attr[i].string_value())
10735 out_attr[i].set_string_value("");
10736 break;
10738 default:
10740 const char* err_object = NULL;
10742 // The "known_obj_attributes" table does contain some undefined
10743 // attributes. Ensure that there are unused.
10744 if (out_attr[i].int_value() != 0
10745 || out_attr[i].string_value() != "")
10746 err_object = "output";
10747 else if (in_attr[i].int_value() != 0
10748 || in_attr[i].string_value() != "")
10749 err_object = name;
10751 if (err_object != NULL
10752 && parameters->options().warn_mismatch())
10754 // Attribute numbers >=64 (mod 128) can be safely ignored.
10755 if ((i & 127) < 64)
10756 gold_error(_("%s: unknown mandatory EABI object attribute "
10757 "%d"),
10758 err_object, i);
10759 else
10760 gold_warning(_("%s: unknown EABI object attribute %d"),
10761 err_object, i);
10764 // Only pass on attributes that match in both inputs.
10765 if (!in_attr[i].matches(out_attr[i]))
10767 out_attr[i].set_int_value(0);
10768 out_attr[i].set_string_value("");
10773 // If out_attr was copied from in_attr then it won't have a type yet.
10774 if (in_attr[i].type() && !out_attr[i].type())
10775 out_attr[i].set_type(in_attr[i].type());
10778 // Merge Tag_compatibility attributes and any common GNU ones.
10779 this->attributes_section_data_->merge(name, pasd);
10781 // Check for any attributes not known on ARM.
10782 typedef Vendor_object_attributes::Other_attributes Other_attributes;
10783 const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10784 Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10785 Other_attributes* out_other_attributes =
10786 this->attributes_section_data_->other_attributes(vendor);
10787 Other_attributes::iterator out_iter = out_other_attributes->begin();
10789 while (in_iter != in_other_attributes->end()
10790 || out_iter != out_other_attributes->end())
10792 const char* err_object = NULL;
10793 int err_tag = 0;
10795 // The tags for each list are in numerical order.
10796 // If the tags are equal, then merge.
10797 if (out_iter != out_other_attributes->end()
10798 && (in_iter == in_other_attributes->end()
10799 || in_iter->first > out_iter->first))
10801 // This attribute only exists in output. We can't merge, and we
10802 // don't know what the tag means, so delete it.
10803 err_object = "output";
10804 err_tag = out_iter->first;
10805 int saved_tag = out_iter->first;
10806 delete out_iter->second;
10807 out_other_attributes->erase(out_iter);
10808 out_iter = out_other_attributes->upper_bound(saved_tag);
10810 else if (in_iter != in_other_attributes->end()
10811 && (out_iter != out_other_attributes->end()
10812 || in_iter->first < out_iter->first))
10814 // This attribute only exists in input. We can't merge, and we
10815 // don't know what the tag means, so ignore it.
10816 err_object = name;
10817 err_tag = in_iter->first;
10818 ++in_iter;
10820 else // The tags are equal.
10822 // As present, all attributes in the list are unknown, and
10823 // therefore can't be merged meaningfully.
10824 err_object = "output";
10825 err_tag = out_iter->first;
10827 // Only pass on attributes that match in both inputs.
10828 if (!in_iter->second->matches(*(out_iter->second)))
10830 // No match. Delete the attribute.
10831 int saved_tag = out_iter->first;
10832 delete out_iter->second;
10833 out_other_attributes->erase(out_iter);
10834 out_iter = out_other_attributes->upper_bound(saved_tag);
10836 else
10838 // Matched. Keep the attribute and move to the next.
10839 ++out_iter;
10840 ++in_iter;
10844 if (err_object && parameters->options().warn_mismatch())
10846 // Attribute numbers >=64 (mod 128) can be safely ignored. */
10847 if ((err_tag & 127) < 64)
10849 gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10850 err_object, err_tag);
10852 else
10854 gold_warning(_("%s: unknown EABI object attribute %d"),
10855 err_object, err_tag);
10861 // Stub-generation methods for Target_arm.
10863 // Make a new Arm_input_section object.
10865 template<bool big_endian>
10866 Arm_input_section<big_endian>*
10867 Target_arm<big_endian>::new_arm_input_section(
10868 Relobj* relobj,
10869 unsigned int shndx)
10871 Section_id sid(relobj, shndx);
10873 Arm_input_section<big_endian>* arm_input_section =
10874 new Arm_input_section<big_endian>(relobj, shndx);
10875 arm_input_section->init();
10877 // Register new Arm_input_section in map for look-up.
10878 std::pair<typename Arm_input_section_map::iterator, bool> ins =
10879 this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
10881 // Make sure that it we have not created another Arm_input_section
10882 // for this input section already.
10883 gold_assert(ins.second);
10885 return arm_input_section;
10888 // Find the Arm_input_section object corresponding to the SHNDX-th input
10889 // section of RELOBJ.
10891 template<bool big_endian>
10892 Arm_input_section<big_endian>*
10893 Target_arm<big_endian>::find_arm_input_section(
10894 Relobj* relobj,
10895 unsigned int shndx) const
10897 Section_id sid(relobj, shndx);
10898 typename Arm_input_section_map::const_iterator p =
10899 this->arm_input_section_map_.find(sid);
10900 return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
10903 // Make a new stub table.
10905 template<bool big_endian>
10906 Stub_table<big_endian>*
10907 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
10909 Stub_table<big_endian>* stub_table =
10910 new Stub_table<big_endian>(owner);
10911 this->stub_tables_.push_back(stub_table);
10913 stub_table->set_address(owner->address() + owner->data_size());
10914 stub_table->set_file_offset(owner->offset() + owner->data_size());
10915 stub_table->finalize_data_size();
10917 return stub_table;
10920 // Scan a relocation for stub generation.
10922 template<bool big_endian>
10923 void
10924 Target_arm<big_endian>::scan_reloc_for_stub(
10925 const Relocate_info<32, big_endian>* relinfo,
10926 unsigned int r_type,
10927 const Sized_symbol<32>* gsym,
10928 unsigned int r_sym,
10929 const Symbol_value<32>* psymval,
10930 elfcpp::Elf_types<32>::Elf_Swxword addend,
10931 Arm_address address)
10933 typedef typename Target_arm<big_endian>::Relocate Relocate;
10935 const Arm_relobj<big_endian>* arm_relobj =
10936 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10938 bool target_is_thumb;
10939 Symbol_value<32> symval;
10940 if (gsym != NULL)
10942 // This is a global symbol. Determine if we use PLT and if the
10943 // final target is THUMB.
10944 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
10946 // This uses a PLT, change the symbol value.
10947 symval.set_output_value(this->plt_section()->address()
10948 + gsym->plt_offset());
10949 psymval = &symval;
10950 target_is_thumb = false;
10952 else if (gsym->is_undefined())
10953 // There is no need to generate a stub symbol is undefined.
10954 return;
10955 else
10957 target_is_thumb =
10958 ((gsym->type() == elfcpp::STT_ARM_TFUNC)
10959 || (gsym->type() == elfcpp::STT_FUNC
10960 && !gsym->is_undefined()
10961 && ((psymval->value(arm_relobj, 0) & 1) != 0)));
10964 else
10966 // This is a local symbol. Determine if the final target is THUMB.
10967 target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
10970 // Strip LSB if this points to a THUMB target.
10971 const Arm_reloc_property* reloc_property =
10972 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10973 gold_assert(reloc_property != NULL);
10974 if (target_is_thumb
10975 && reloc_property->uses_thumb_bit()
10976 && ((psymval->value(arm_relobj, 0) & 1) != 0))
10978 Arm_address stripped_value =
10979 psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
10980 symval.set_output_value(stripped_value);
10981 psymval = &symval;
10984 // Get the symbol value.
10985 Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
10987 // Owing to pipelining, the PC relative branches below actually skip
10988 // two instructions when the branch offset is 0.
10989 Arm_address destination;
10990 switch (r_type)
10992 case elfcpp::R_ARM_CALL:
10993 case elfcpp::R_ARM_JUMP24:
10994 case elfcpp::R_ARM_PLT32:
10995 // ARM branches.
10996 destination = value + addend + 8;
10997 break;
10998 case elfcpp::R_ARM_THM_CALL:
10999 case elfcpp::R_ARM_THM_XPC22:
11000 case elfcpp::R_ARM_THM_JUMP24:
11001 case elfcpp::R_ARM_THM_JUMP19:
11002 // THUMB branches.
11003 destination = value + addend + 4;
11004 break;
11005 default:
11006 gold_unreachable();
11009 Reloc_stub* stub = NULL;
11010 Stub_type stub_type =
11011 Reloc_stub::stub_type_for_reloc(r_type, address, destination,
11012 target_is_thumb);
11013 if (stub_type != arm_stub_none)
11015 // Try looking up an existing stub from a stub table.
11016 Stub_table<big_endian>* stub_table =
11017 arm_relobj->stub_table(relinfo->data_shndx);
11018 gold_assert(stub_table != NULL);
11020 // Locate stub by destination.
11021 Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
11023 // Create a stub if there is not one already
11024 stub = stub_table->find_reloc_stub(stub_key);
11025 if (stub == NULL)
11027 // create a new stub and add it to stub table.
11028 stub = this->stub_factory().make_reloc_stub(stub_type);
11029 stub_table->add_reloc_stub(stub, stub_key);
11032 // Record the destination address.
11033 stub->set_destination_address(destination
11034 | (target_is_thumb ? 1 : 0));
11037 // For Cortex-A8, we need to record a relocation at 4K page boundary.
11038 if (this->fix_cortex_a8_
11039 && (r_type == elfcpp::R_ARM_THM_JUMP24
11040 || r_type == elfcpp::R_ARM_THM_JUMP19
11041 || r_type == elfcpp::R_ARM_THM_CALL
11042 || r_type == elfcpp::R_ARM_THM_XPC22)
11043 && (address & 0xfffU) == 0xffeU)
11045 // Found a candidate. Note we haven't checked the destination is
11046 // within 4K here: if we do so (and don't create a record) we can't
11047 // tell that a branch should have been relocated when scanning later.
11048 this->cortex_a8_relocs_info_[address] =
11049 new Cortex_a8_reloc(stub, r_type,
11050 destination | (target_is_thumb ? 1 : 0));
11054 // This function scans a relocation sections for stub generation.
11055 // The template parameter Relocate must be a class type which provides
11056 // a single function, relocate(), which implements the machine
11057 // specific part of a relocation.
11059 // BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type:
11060 // SHT_REL or SHT_RELA.
11062 // PRELOCS points to the relocation data. RELOC_COUNT is the number
11063 // of relocs. OUTPUT_SECTION is the output section.
11064 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
11065 // mapped to output offsets.
11067 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
11068 // VIEW_SIZE is the size. These refer to the input section, unless
11069 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
11070 // the output section.
11072 template<bool big_endian>
11073 template<int sh_type>
11074 void inline
11075 Target_arm<big_endian>::scan_reloc_section_for_stubs(
11076 const Relocate_info<32, big_endian>* relinfo,
11077 const unsigned char* prelocs,
11078 size_t reloc_count,
11079 Output_section* output_section,
11080 bool needs_special_offset_handling,
11081 const unsigned char* view,
11082 elfcpp::Elf_types<32>::Elf_Addr view_address,
11083 section_size_type)
11085 typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
11086 const int reloc_size =
11087 Reloc_types<sh_type, 32, big_endian>::reloc_size;
11089 Arm_relobj<big_endian>* arm_object =
11090 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11091 unsigned int local_count = arm_object->local_symbol_count();
11093 Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11095 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11097 Reltype reloc(prelocs);
11099 typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11100 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11101 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11103 r_type = this->get_real_reloc_type(r_type);
11105 // Only a few relocation types need stubs.
11106 if ((r_type != elfcpp::R_ARM_CALL)
11107 && (r_type != elfcpp::R_ARM_JUMP24)
11108 && (r_type != elfcpp::R_ARM_PLT32)
11109 && (r_type != elfcpp::R_ARM_THM_CALL)
11110 && (r_type != elfcpp::R_ARM_THM_XPC22)
11111 && (r_type != elfcpp::R_ARM_THM_JUMP24)
11112 && (r_type != elfcpp::R_ARM_THM_JUMP19)
11113 && (r_type != elfcpp::R_ARM_V4BX))
11114 continue;
11116 section_offset_type offset =
11117 convert_to_section_size_type(reloc.get_r_offset());
11119 if (needs_special_offset_handling)
11121 offset = output_section->output_offset(relinfo->object,
11122 relinfo->data_shndx,
11123 offset);
11124 if (offset == -1)
11125 continue;
11128 // Create a v4bx stub if --fix-v4bx-interworking is used.
11129 if (r_type == elfcpp::R_ARM_V4BX)
11131 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11133 // Get the BX instruction.
11134 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11135 const Valtype* wv =
11136 reinterpret_cast<const Valtype*>(view + offset);
11137 elfcpp::Elf_types<32>::Elf_Swxword insn =
11138 elfcpp::Swap<32, big_endian>::readval(wv);
11139 const uint32_t reg = (insn & 0xf);
11141 if (reg < 0xf)
11143 // Try looking up an existing stub from a stub table.
11144 Stub_table<big_endian>* stub_table =
11145 arm_object->stub_table(relinfo->data_shndx);
11146 gold_assert(stub_table != NULL);
11148 if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11150 // create a new stub and add it to stub table.
11151 Arm_v4bx_stub* stub =
11152 this->stub_factory().make_arm_v4bx_stub(reg);
11153 gold_assert(stub != NULL);
11154 stub_table->add_arm_v4bx_stub(stub);
11158 continue;
11161 // Get the addend.
11162 Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11163 elfcpp::Elf_types<32>::Elf_Swxword addend =
11164 stub_addend_reader(r_type, view + offset, reloc);
11166 const Sized_symbol<32>* sym;
11168 Symbol_value<32> symval;
11169 const Symbol_value<32> *psymval;
11170 bool is_defined_in_discarded_section;
11171 unsigned int shndx;
11172 if (r_sym < local_count)
11174 sym = NULL;
11175 psymval = arm_object->local_symbol(r_sym);
11177 // If the local symbol belongs to a section we are discarding,
11178 // and that section is a debug section, try to find the
11179 // corresponding kept section and map this symbol to its
11180 // counterpart in the kept section. The symbol must not
11181 // correspond to a section we are folding.
11182 bool is_ordinary;
11183 shndx = psymval->input_shndx(&is_ordinary);
11184 is_defined_in_discarded_section =
11185 (is_ordinary
11186 && shndx != elfcpp::SHN_UNDEF
11187 && !arm_object->is_section_included(shndx)
11188 && !relinfo->symtab->is_section_folded(arm_object, shndx));
11190 // We need to compute the would-be final value of this local
11191 // symbol.
11192 if (!is_defined_in_discarded_section)
11194 typedef Sized_relobj_file<32, big_endian> ObjType;
11195 typename ObjType::Compute_final_local_value_status status =
11196 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11197 relinfo->symtab);
11198 if (status == ObjType::CFLV_OK)
11200 // Currently we cannot handle a branch to a target in
11201 // a merged section. If this is the case, issue an error
11202 // and also free the merge symbol value.
11203 if (!symval.has_output_value())
11205 const std::string& section_name =
11206 arm_object->section_name(shndx);
11207 arm_object->error(_("cannot handle branch to local %u "
11208 "in a merged section %s"),
11209 r_sym, section_name.c_str());
11211 psymval = &symval;
11213 else
11215 // We cannot determine the final value.
11216 continue;
11220 else
11222 const Symbol* gsym;
11223 gsym = arm_object->global_symbol(r_sym);
11224 gold_assert(gsym != NULL);
11225 if (gsym->is_forwarder())
11226 gsym = relinfo->symtab->resolve_forwards(gsym);
11228 sym = static_cast<const Sized_symbol<32>*>(gsym);
11229 if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11230 symval.set_output_symtab_index(sym->symtab_index());
11231 else
11232 symval.set_no_output_symtab_entry();
11234 // We need to compute the would-be final value of this global
11235 // symbol.
11236 const Symbol_table* symtab = relinfo->symtab;
11237 const Sized_symbol<32>* sized_symbol =
11238 symtab->get_sized_symbol<32>(gsym);
11239 Symbol_table::Compute_final_value_status status;
11240 Arm_address value =
11241 symtab->compute_final_value<32>(sized_symbol, &status);
11243 // Skip this if the symbol has not output section.
11244 if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11245 continue;
11246 symval.set_output_value(value);
11248 if (gsym->type() == elfcpp::STT_TLS)
11249 symval.set_is_tls_symbol();
11250 else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11251 symval.set_is_ifunc_symbol();
11252 psymval = &symval;
11254 is_defined_in_discarded_section =
11255 (gsym->is_defined_in_discarded_section()
11256 && gsym->is_undefined());
11257 shndx = 0;
11260 Symbol_value<32> symval2;
11261 if (is_defined_in_discarded_section)
11263 if (comdat_behavior == CB_UNDETERMINED)
11265 std::string name = arm_object->section_name(relinfo->data_shndx);
11266 comdat_behavior = get_comdat_behavior(name.c_str());
11268 if (comdat_behavior == CB_PRETEND)
11270 // FIXME: This case does not work for global symbols.
11271 // We have no place to store the original section index.
11272 // Fortunately this does not matter for comdat sections,
11273 // only for sections explicitly discarded by a linker
11274 // script.
11275 bool found;
11276 typename elfcpp::Elf_types<32>::Elf_Addr value =
11277 arm_object->map_to_kept_section(shndx, &found);
11278 if (found)
11279 symval2.set_output_value(value + psymval->input_value());
11280 else
11281 symval2.set_output_value(0);
11283 else
11285 if (comdat_behavior == CB_WARNING)
11286 gold_warning_at_location(relinfo, i, offset,
11287 _("relocation refers to discarded "
11288 "section"));
11289 symval2.set_output_value(0);
11291 symval2.set_no_output_symtab_entry();
11292 psymval = &symval2;
11295 // If symbol is a section symbol, we don't know the actual type of
11296 // destination. Give up.
11297 if (psymval->is_section_symbol())
11298 continue;
11300 this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11301 addend, view_address + offset);
11305 // Scan an input section for stub generation.
11307 template<bool big_endian>
11308 void
11309 Target_arm<big_endian>::scan_section_for_stubs(
11310 const Relocate_info<32, big_endian>* relinfo,
11311 unsigned int sh_type,
11312 const unsigned char* prelocs,
11313 size_t reloc_count,
11314 Output_section* output_section,
11315 bool needs_special_offset_handling,
11316 const unsigned char* view,
11317 Arm_address view_address,
11318 section_size_type view_size)
11320 if (sh_type == elfcpp::SHT_REL)
11321 this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11322 relinfo,
11323 prelocs,
11324 reloc_count,
11325 output_section,
11326 needs_special_offset_handling,
11327 view,
11328 view_address,
11329 view_size);
11330 else if (sh_type == elfcpp::SHT_RELA)
11331 // We do not support RELA type relocations yet. This is provided for
11332 // completeness.
11333 this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11334 relinfo,
11335 prelocs,
11336 reloc_count,
11337 output_section,
11338 needs_special_offset_handling,
11339 view,
11340 view_address,
11341 view_size);
11342 else
11343 gold_unreachable();
11346 // Group input sections for stub generation.
11348 // We group input sections in an output section so that the total size,
11349 // including any padding space due to alignment is smaller than GROUP_SIZE
11350 // unless the only input section in group is bigger than GROUP_SIZE already.
11351 // Then an ARM stub table is created to follow the last input section
11352 // in group. For each group an ARM stub table is created an is placed
11353 // after the last group. If STUB_ALWAYS_AFTER_BRANCH is false, we further
11354 // extend the group after the stub table.
11356 template<bool big_endian>
11357 void
11358 Target_arm<big_endian>::group_sections(
11359 Layout* layout,
11360 section_size_type group_size,
11361 bool stubs_always_after_branch,
11362 const Task* task)
11364 // Group input sections and insert stub table
11365 Layout::Section_list section_list;
11366 layout->get_allocated_sections(&section_list);
11367 for (Layout::Section_list::const_iterator p = section_list.begin();
11368 p != section_list.end();
11369 ++p)
11371 Arm_output_section<big_endian>* output_section =
11372 Arm_output_section<big_endian>::as_arm_output_section(*p);
11373 output_section->group_sections(group_size, stubs_always_after_branch,
11374 this, task);
11378 // Relaxation hook. This is where we do stub generation.
11380 template<bool big_endian>
11381 bool
11382 Target_arm<big_endian>::do_relax(
11383 int pass,
11384 const Input_objects* input_objects,
11385 Symbol_table* symtab,
11386 Layout* layout,
11387 const Task* task)
11389 // No need to generate stubs if this is a relocatable link.
11390 gold_assert(!parameters->options().relocatable());
11392 // If this is the first pass, we need to group input sections into
11393 // stub groups.
11394 bool done_exidx_fixup = false;
11395 typedef typename Stub_table_list::iterator Stub_table_iterator;
11396 if (pass == 1)
11398 // Determine the stub group size. The group size is the absolute
11399 // value of the parameter --stub-group-size. If --stub-group-size
11400 // is passed a negative value, we restrict stubs to be always after
11401 // the stubbed branches.
11402 int32_t stub_group_size_param =
11403 parameters->options().stub_group_size();
11404 bool stubs_always_after_branch = stub_group_size_param < 0;
11405 section_size_type stub_group_size = abs(stub_group_size_param);
11407 if (stub_group_size == 1)
11409 // Default value.
11410 // Thumb branch range is +-4MB has to be used as the default
11411 // maximum size (a given section can contain both ARM and Thumb
11412 // code, so the worst case has to be taken into account). If we are
11413 // fixing cortex-a8 errata, the branch range has to be even smaller,
11414 // since wide conditional branch has a range of +-1MB only.
11416 // This value is 48K less than that, which allows for 4096
11417 // 12-byte stubs. If we exceed that, then we will fail to link.
11418 // The user will have to relink with an explicit group size
11419 // option.
11420 stub_group_size = 4145152;
11423 // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11424 // page as the first half of a 32-bit branch straddling two 4K pages.
11425 // This is a crude way of enforcing that. In addition, long conditional
11426 // branches of THUMB-2 have a range of +-1M. If we are fixing cortex-A8
11427 // erratum, limit the group size to (1M - 12k) to avoid unreachable
11428 // cortex-A8 stubs from long conditional branches.
11429 if (this->fix_cortex_a8_)
11431 stubs_always_after_branch = true;
11432 const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11433 stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11436 group_sections(layout, stub_group_size, stubs_always_after_branch, task);
11438 // Also fix .ARM.exidx section coverage.
11439 Arm_output_section<big_endian>* exidx_output_section = NULL;
11440 for (Layout::Section_list::const_iterator p =
11441 layout->section_list().begin();
11442 p != layout->section_list().end();
11443 ++p)
11444 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11446 if (exidx_output_section == NULL)
11447 exidx_output_section =
11448 Arm_output_section<big_endian>::as_arm_output_section(*p);
11449 else
11450 // We cannot handle this now.
11451 gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11452 "non-relocatable link"),
11453 exidx_output_section->name(),
11454 (*p)->name());
11457 if (exidx_output_section != NULL)
11459 this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11460 symtab, task);
11461 done_exidx_fixup = true;
11464 else
11466 // If this is not the first pass, addresses and file offsets have
11467 // been reset at this point, set them here.
11468 for (Stub_table_iterator sp = this->stub_tables_.begin();
11469 sp != this->stub_tables_.end();
11470 ++sp)
11472 Arm_input_section<big_endian>* owner = (*sp)->owner();
11473 off_t off = align_address(owner->original_size(),
11474 (*sp)->addralign());
11475 (*sp)->set_address_and_file_offset(owner->address() + off,
11476 owner->offset() + off);
11480 // The Cortex-A8 stubs are sensitive to layout of code sections. At the
11481 // beginning of each relaxation pass, just blow away all the stubs.
11482 // Alternatively, we could selectively remove only the stubs and reloc
11483 // information for code sections that have moved since the last pass.
11484 // That would require more book-keeping.
11485 if (this->fix_cortex_a8_)
11487 // Clear all Cortex-A8 reloc information.
11488 for (typename Cortex_a8_relocs_info::const_iterator p =
11489 this->cortex_a8_relocs_info_.begin();
11490 p != this->cortex_a8_relocs_info_.end();
11491 ++p)
11492 delete p->second;
11493 this->cortex_a8_relocs_info_.clear();
11495 // Remove all Cortex-A8 stubs.
11496 for (Stub_table_iterator sp = this->stub_tables_.begin();
11497 sp != this->stub_tables_.end();
11498 ++sp)
11499 (*sp)->remove_all_cortex_a8_stubs();
11502 // Scan relocs for relocation stubs
11503 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11504 op != input_objects->relobj_end();
11505 ++op)
11507 Arm_relobj<big_endian>* arm_relobj =
11508 Arm_relobj<big_endian>::as_arm_relobj(*op);
11509 // Lock the object so we can read from it. This is only called
11510 // single-threaded from Layout::finalize, so it is OK to lock.
11511 Task_lock_obj<Object> tl(task, arm_relobj);
11512 arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11515 // Check all stub tables to see if any of them have their data sizes
11516 // or addresses alignments changed. These are the only things that
11517 // matter.
11518 bool any_stub_table_changed = false;
11519 Unordered_set<const Output_section*> sections_needing_adjustment;
11520 for (Stub_table_iterator sp = this->stub_tables_.begin();
11521 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11522 ++sp)
11524 if ((*sp)->update_data_size_and_addralign())
11526 // Update data size of stub table owner.
11527 Arm_input_section<big_endian>* owner = (*sp)->owner();
11528 uint64_t address = owner->address();
11529 off_t offset = owner->offset();
11530 owner->reset_address_and_file_offset();
11531 owner->set_address_and_file_offset(address, offset);
11533 sections_needing_adjustment.insert(owner->output_section());
11534 any_stub_table_changed = true;
11538 // Output_section_data::output_section() returns a const pointer but we
11539 // need to update output sections, so we record all output sections needing
11540 // update above and scan the sections here to find out what sections need
11541 // to be updated.
11542 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
11543 p != layout->section_list().end();
11544 ++p)
11546 if (sections_needing_adjustment.find(*p)
11547 != sections_needing_adjustment.end())
11548 (*p)->set_section_offsets_need_adjustment();
11551 // Stop relaxation if no EXIDX fix-up and no stub table change.
11552 bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11554 // Finalize the stubs in the last relaxation pass.
11555 if (!continue_relaxation)
11557 for (Stub_table_iterator sp = this->stub_tables_.begin();
11558 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11559 ++sp)
11560 (*sp)->finalize_stubs();
11562 // Update output local symbol counts of objects if necessary.
11563 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11564 op != input_objects->relobj_end();
11565 ++op)
11567 Arm_relobj<big_endian>* arm_relobj =
11568 Arm_relobj<big_endian>::as_arm_relobj(*op);
11570 // Update output local symbol counts. We need to discard local
11571 // symbols defined in parts of input sections that are discarded by
11572 // relaxation.
11573 if (arm_relobj->output_local_symbol_count_needs_update())
11575 // We need to lock the object's file to update it.
11576 Task_lock_obj<Object> tl(task, arm_relobj);
11577 arm_relobj->update_output_local_symbol_count();
11582 return continue_relaxation;
11585 // Relocate a stub.
11587 template<bool big_endian>
11588 void
11589 Target_arm<big_endian>::relocate_stub(
11590 Stub* stub,
11591 const Relocate_info<32, big_endian>* relinfo,
11592 Output_section* output_section,
11593 unsigned char* view,
11594 Arm_address address,
11595 section_size_type view_size)
11597 Relocate relocate;
11598 const Stub_template* stub_template = stub->stub_template();
11599 for (size_t i = 0; i < stub_template->reloc_count(); i++)
11601 size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11602 const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11604 unsigned int r_type = insn->r_type();
11605 section_size_type reloc_offset = stub_template->reloc_offset(i);
11606 section_size_type reloc_size = insn->size();
11607 gold_assert(reloc_offset + reloc_size <= view_size);
11609 // This is the address of the stub destination.
11610 Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11611 Symbol_value<32> symval;
11612 symval.set_output_value(target);
11614 // Synthesize a fake reloc just in case. We don't have a symbol so
11615 // we use 0.
11616 unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11617 memset(reloc_buffer, 0, sizeof(reloc_buffer));
11618 elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11619 reloc_write.put_r_offset(reloc_offset);
11620 reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11621 elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11623 relocate.relocate(relinfo, this, output_section,
11624 this->fake_relnum_for_stubs, rel, r_type,
11625 NULL, &symval, view + reloc_offset,
11626 address + reloc_offset, reloc_size);
11630 // Determine whether an object attribute tag takes an integer, a
11631 // string or both.
11633 template<bool big_endian>
11635 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11637 if (tag == Object_attribute::Tag_compatibility)
11638 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11639 | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11640 else if (tag == elfcpp::Tag_nodefaults)
11641 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11642 | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11643 else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11644 return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11645 else if (tag < 32)
11646 return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11647 else
11648 return ((tag & 1) != 0
11649 ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11650 : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11653 // Reorder attributes.
11655 // The ABI defines that Tag_conformance should be emitted first, and that
11656 // Tag_nodefaults should be second (if either is defined). This sets those
11657 // two positions, and bumps up the position of all the remaining tags to
11658 // compensate.
11660 template<bool big_endian>
11662 Target_arm<big_endian>::do_attributes_order(int num) const
11664 // Reorder the known object attributes in output. We want to move
11665 // Tag_conformance to position 4 and Tag_conformance to position 5
11666 // and shift everything between 4 .. Tag_conformance - 1 to make room.
11667 if (num == 4)
11668 return elfcpp::Tag_conformance;
11669 if (num == 5)
11670 return elfcpp::Tag_nodefaults;
11671 if ((num - 2) < elfcpp::Tag_nodefaults)
11672 return num - 2;
11673 if ((num - 1) < elfcpp::Tag_conformance)
11674 return num - 1;
11675 return num;
11678 // Scan a span of THUMB code for Cortex-A8 erratum.
11680 template<bool big_endian>
11681 void
11682 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11683 Arm_relobj<big_endian>* arm_relobj,
11684 unsigned int shndx,
11685 section_size_type span_start,
11686 section_size_type span_end,
11687 const unsigned char* view,
11688 Arm_address address)
11690 // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11692 // The opcode is BLX.W, BL.W, B.W, Bcc.W
11693 // The branch target is in the same 4KB region as the
11694 // first half of the branch.
11695 // The instruction before the branch is a 32-bit
11696 // length non-branch instruction.
11697 section_size_type i = span_start;
11698 bool last_was_32bit = false;
11699 bool last_was_branch = false;
11700 while (i < span_end)
11702 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11703 const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11704 uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11705 bool is_blx = false, is_b = false;
11706 bool is_bl = false, is_bcc = false;
11708 bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11709 if (insn_32bit)
11711 // Load the rest of the insn (in manual-friendly order).
11712 insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11714 // Encoding T4: B<c>.W.
11715 is_b = (insn & 0xf800d000U) == 0xf0009000U;
11716 // Encoding T1: BL<c>.W.
11717 is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11718 // Encoding T2: BLX<c>.W.
11719 is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11720 // Encoding T3: B<c>.W (not permitted in IT block).
11721 is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11722 && (insn & 0x07f00000U) != 0x03800000U);
11725 bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11727 // If this instruction is a 32-bit THUMB branch that crosses a 4K
11728 // page boundary and it follows 32-bit non-branch instruction,
11729 // we need to work around.
11730 if (is_32bit_branch
11731 && ((address + i) & 0xfffU) == 0xffeU
11732 && last_was_32bit
11733 && !last_was_branch)
11735 // Check to see if there is a relocation stub for this branch.
11736 bool force_target_arm = false;
11737 bool force_target_thumb = false;
11738 const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11739 Cortex_a8_relocs_info::const_iterator p =
11740 this->cortex_a8_relocs_info_.find(address + i);
11742 if (p != this->cortex_a8_relocs_info_.end())
11744 cortex_a8_reloc = p->second;
11745 bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11747 if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11748 && !target_is_thumb)
11749 force_target_arm = true;
11750 else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11751 && target_is_thumb)
11752 force_target_thumb = true;
11755 off_t offset;
11756 Stub_type stub_type = arm_stub_none;
11758 // Check if we have an offending branch instruction.
11759 uint16_t upper_insn = (insn >> 16) & 0xffffU;
11760 uint16_t lower_insn = insn & 0xffffU;
11761 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
11763 if (cortex_a8_reloc != NULL
11764 && cortex_a8_reloc->reloc_stub() != NULL)
11765 // We've already made a stub for this instruction, e.g.
11766 // it's a long branch or a Thumb->ARM stub. Assume that
11767 // stub will suffice to work around the A8 erratum (see
11768 // setting of always_after_branch above).
11770 else if (is_bcc)
11772 offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11773 lower_insn);
11774 stub_type = arm_stub_a8_veneer_b_cond;
11776 else if (is_b || is_bl || is_blx)
11778 offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11779 lower_insn);
11780 if (is_blx)
11781 offset &= ~3;
11783 stub_type = (is_blx
11784 ? arm_stub_a8_veneer_blx
11785 : (is_bl
11786 ? arm_stub_a8_veneer_bl
11787 : arm_stub_a8_veneer_b));
11790 if (stub_type != arm_stub_none)
11792 Arm_address pc_for_insn = address + i + 4;
11794 // The original instruction is a BL, but the target is
11795 // an ARM instruction. If we were not making a stub,
11796 // the BL would have been converted to a BLX. Use the
11797 // BLX stub instead in that case.
11798 if (this->may_use_blx() && force_target_arm
11799 && stub_type == arm_stub_a8_veneer_bl)
11801 stub_type = arm_stub_a8_veneer_blx;
11802 is_blx = true;
11803 is_bl = false;
11805 // Conversely, if the original instruction was
11806 // BLX but the target is Thumb mode, use the BL stub.
11807 else if (force_target_thumb
11808 && stub_type == arm_stub_a8_veneer_blx)
11810 stub_type = arm_stub_a8_veneer_bl;
11811 is_blx = false;
11812 is_bl = true;
11815 if (is_blx)
11816 pc_for_insn &= ~3;
11818 // If we found a relocation, use the proper destination,
11819 // not the offset in the (unrelocated) instruction.
11820 // Note this is always done if we switched the stub type above.
11821 if (cortex_a8_reloc != NULL)
11822 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11824 Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11826 // Add a new stub if destination address in in the same page.
11827 if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11829 Cortex_a8_stub* stub =
11830 this->stub_factory_.make_cortex_a8_stub(stub_type,
11831 arm_relobj, shndx,
11832 address + i,
11833 target, insn);
11834 Stub_table<big_endian>* stub_table =
11835 arm_relobj->stub_table(shndx);
11836 gold_assert(stub_table != NULL);
11837 stub_table->add_cortex_a8_stub(address + i, stub);
11842 i += insn_32bit ? 4 : 2;
11843 last_was_32bit = insn_32bit;
11844 last_was_branch = is_32bit_branch;
11848 // Apply the Cortex-A8 workaround.
11850 template<bool big_endian>
11851 void
11852 Target_arm<big_endian>::apply_cortex_a8_workaround(
11853 const Cortex_a8_stub* stub,
11854 Arm_address stub_address,
11855 unsigned char* insn_view,
11856 Arm_address insn_address)
11858 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11859 Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
11860 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
11861 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
11862 off_t branch_offset = stub_address - (insn_address + 4);
11864 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
11865 switch (stub->stub_template()->type())
11867 case arm_stub_a8_veneer_b_cond:
11868 // For a conditional branch, we re-write it to be an unconditional
11869 // branch to the stub. We use the THUMB-2 encoding here.
11870 upper_insn = 0xf000U;
11871 lower_insn = 0xb800U;
11872 // Fall through
11873 case arm_stub_a8_veneer_b:
11874 case arm_stub_a8_veneer_bl:
11875 case arm_stub_a8_veneer_blx:
11876 if ((lower_insn & 0x5000U) == 0x4000U)
11877 // For a BLX instruction, make sure that the relocation is
11878 // rounded up to a word boundary. This follows the semantics of
11879 // the instruction which specifies that bit 1 of the target
11880 // address will come from bit 1 of the base address.
11881 branch_offset = (branch_offset + 2) & ~3;
11883 // Put BRANCH_OFFSET back into the insn.
11884 gold_assert(!utils::has_overflow<25>(branch_offset));
11885 upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
11886 lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
11887 break;
11889 default:
11890 gold_unreachable();
11893 // Put the relocated value back in the object file:
11894 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
11895 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
11898 template<bool big_endian>
11899 class Target_selector_arm : public Target_selector
11901 public:
11902 Target_selector_arm()
11903 : Target_selector(elfcpp::EM_ARM, 32, big_endian,
11904 (big_endian ? "elf32-bigarm" : "elf32-littlearm"))
11907 Target*
11908 do_instantiate_target()
11909 { return new Target_arm<big_endian>(); }
11912 // Fix .ARM.exidx section coverage.
11914 template<bool big_endian>
11915 void
11916 Target_arm<big_endian>::fix_exidx_coverage(
11917 Layout* layout,
11918 const Input_objects* input_objects,
11919 Arm_output_section<big_endian>* exidx_section,
11920 Symbol_table* symtab,
11921 const Task* task)
11923 // We need to look at all the input sections in output in ascending
11924 // order of of output address. We do that by building a sorted list
11925 // of output sections by addresses. Then we looks at the output sections
11926 // in order. The input sections in an output section are already sorted
11927 // by addresses within the output section.
11929 typedef std::set<Output_section*, output_section_address_less_than>
11930 Sorted_output_section_list;
11931 Sorted_output_section_list sorted_output_sections;
11933 // Find out all the output sections of input sections pointed by
11934 // EXIDX input sections.
11935 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
11936 p != input_objects->relobj_end();
11937 ++p)
11939 Arm_relobj<big_endian>* arm_relobj =
11940 Arm_relobj<big_endian>::as_arm_relobj(*p);
11941 std::vector<unsigned int> shndx_list;
11942 arm_relobj->get_exidx_shndx_list(&shndx_list);
11943 for (size_t i = 0; i < shndx_list.size(); ++i)
11945 const Arm_exidx_input_section* exidx_input_section =
11946 arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
11947 gold_assert(exidx_input_section != NULL);
11948 if (!exidx_input_section->has_errors())
11950 unsigned int text_shndx = exidx_input_section->link();
11951 Output_section* os = arm_relobj->output_section(text_shndx);
11952 if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
11953 sorted_output_sections.insert(os);
11958 // Go over the output sections in ascending order of output addresses.
11959 typedef typename Arm_output_section<big_endian>::Text_section_list
11960 Text_section_list;
11961 Text_section_list sorted_text_sections;
11962 for (typename Sorted_output_section_list::iterator p =
11963 sorted_output_sections.begin();
11964 p != sorted_output_sections.end();
11965 ++p)
11967 Arm_output_section<big_endian>* arm_output_section =
11968 Arm_output_section<big_endian>::as_arm_output_section(*p);
11969 arm_output_section->append_text_sections_to_list(&sorted_text_sections);
11972 exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
11973 merge_exidx_entries(), task);
11976 Target_selector_arm<false> target_selector_arm;
11977 Target_selector_arm<true> target_selector_armbe;
11979 } // End anonymous namespace.