* po/sr.po: New Serbian translation.
[binutils.git] / gold / arm.cc
blobbc704ccbcb42a2c6564bc56bb179ad4df7c78083
1 // arm.cc -- arm target support for gold.
3 // Copyright 2009, 2010, 2011, 2012 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 and
2079 // have alignment of 1.
2080 case elfcpp::R_ARM_ABS32:
2081 case elfcpp::R_ARM_REL32:
2082 case elfcpp::R_ARM_SBREL32:
2083 case elfcpp::R_ARM_GOTOFF32:
2084 case elfcpp::R_ARM_BASE_PREL:
2085 case elfcpp::R_ARM_GOT_BREL:
2086 case elfcpp::R_ARM_BASE_ABS:
2087 case elfcpp::R_ARM_ABS32_NOI:
2088 case elfcpp::R_ARM_REL32_NOI:
2089 case elfcpp::R_ARM_PLT32_ABS:
2090 case elfcpp::R_ARM_GOT_ABS:
2091 case elfcpp::R_ARM_GOT_PREL:
2092 case elfcpp::R_ARM_TLS_GD32:
2093 case elfcpp::R_ARM_TLS_LDM32:
2094 case elfcpp::R_ARM_TLS_LDO32:
2095 case elfcpp::R_ARM_TLS_IE32:
2096 case elfcpp::R_ARM_TLS_LE32:
2097 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED;
2098 default:
2099 // For all other static relocations, return RELOC_SPECIAL.
2100 return Relocatable_relocs::RELOC_SPECIAL;
2106 template<bool big_endian>
2107 class Target_arm : public Sized_target<32, big_endian>
2109 public:
2110 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
2111 Reloc_section;
2113 // When were are relocating a stub, we pass this as the relocation number.
2114 static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
2116 Target_arm()
2117 : Sized_target<32, big_endian>(&arm_info),
2118 got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
2119 copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL),
2120 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2121 stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2122 should_force_pic_veneer_(false),
2123 arm_input_section_map_(), attributes_section_data_(NULL),
2124 fix_cortex_a8_(false), cortex_a8_relocs_info_()
2127 // Whether we force PCI branch veneers.
2128 bool
2129 should_force_pic_veneer() const
2130 { return this->should_force_pic_veneer_; }
2132 // Set PIC veneer flag.
2133 void
2134 set_should_force_pic_veneer(bool value)
2135 { this->should_force_pic_veneer_ = value; }
2137 // Whether we use THUMB-2 instructions.
2138 bool
2139 using_thumb2() const
2141 Object_attribute* attr =
2142 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2143 int arch = attr->int_value();
2144 return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2147 // Whether we use THUMB/THUMB-2 instructions only.
2148 bool
2149 using_thumb_only() const
2151 Object_attribute* attr =
2152 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2154 if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M
2155 || attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M)
2156 return true;
2157 if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2158 && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2159 return false;
2160 attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2161 return attr->int_value() == 'M';
2164 // Whether we have an NOP instruction. If not, use mov r0, r0 instead.
2165 bool
2166 may_use_arm_nop() const
2168 Object_attribute* attr =
2169 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2170 int arch = attr->int_value();
2171 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2172 || arch == elfcpp::TAG_CPU_ARCH_V6K
2173 || arch == elfcpp::TAG_CPU_ARCH_V7
2174 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2177 // Whether we have THUMB-2 NOP.W instruction.
2178 bool
2179 may_use_thumb2_nop() const
2181 Object_attribute* attr =
2182 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2183 int arch = attr->int_value();
2184 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2185 || arch == elfcpp::TAG_CPU_ARCH_V7
2186 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2189 // Whether we have v4T interworking instructions available.
2190 bool
2191 may_use_v4t_interworking() const
2193 Object_attribute* attr =
2194 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2195 int arch = attr->int_value();
2196 return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2197 && arch != elfcpp::TAG_CPU_ARCH_V4);
2200 // Whether we have v5T interworking instructions available.
2201 bool
2202 may_use_v5t_interworking() const
2204 Object_attribute* attr =
2205 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2206 int arch = attr->int_value();
2207 if (parameters->options().fix_arm1176())
2208 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2209 || arch == elfcpp::TAG_CPU_ARCH_V7
2210 || arch == elfcpp::TAG_CPU_ARCH_V6_M
2211 || arch == elfcpp::TAG_CPU_ARCH_V6S_M
2212 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2213 else
2214 return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2215 && arch != elfcpp::TAG_CPU_ARCH_V4
2216 && arch != elfcpp::TAG_CPU_ARCH_V4T);
2219 // Process the relocations to determine unreferenced sections for
2220 // garbage collection.
2221 void
2222 gc_process_relocs(Symbol_table* symtab,
2223 Layout* layout,
2224 Sized_relobj_file<32, big_endian>* object,
2225 unsigned int data_shndx,
2226 unsigned int sh_type,
2227 const unsigned char* prelocs,
2228 size_t reloc_count,
2229 Output_section* output_section,
2230 bool needs_special_offset_handling,
2231 size_t local_symbol_count,
2232 const unsigned char* plocal_symbols);
2234 // Scan the relocations to look for symbol adjustments.
2235 void
2236 scan_relocs(Symbol_table* symtab,
2237 Layout* layout,
2238 Sized_relobj_file<32, big_endian>* object,
2239 unsigned int data_shndx,
2240 unsigned int sh_type,
2241 const unsigned char* prelocs,
2242 size_t reloc_count,
2243 Output_section* output_section,
2244 bool needs_special_offset_handling,
2245 size_t local_symbol_count,
2246 const unsigned char* plocal_symbols);
2248 // Finalize the sections.
2249 void
2250 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2252 // Return the value to use for a dynamic symbol which requires special
2253 // treatment.
2254 uint64_t
2255 do_dynsym_value(const Symbol*) const;
2257 // Relocate a section.
2258 void
2259 relocate_section(const Relocate_info<32, big_endian>*,
2260 unsigned int sh_type,
2261 const unsigned char* prelocs,
2262 size_t reloc_count,
2263 Output_section* output_section,
2264 bool needs_special_offset_handling,
2265 unsigned char* view,
2266 Arm_address view_address,
2267 section_size_type view_size,
2268 const Reloc_symbol_changes*);
2270 // Scan the relocs during a relocatable link.
2271 void
2272 scan_relocatable_relocs(Symbol_table* symtab,
2273 Layout* layout,
2274 Sized_relobj_file<32, big_endian>* object,
2275 unsigned int data_shndx,
2276 unsigned int sh_type,
2277 const unsigned char* prelocs,
2278 size_t reloc_count,
2279 Output_section* output_section,
2280 bool needs_special_offset_handling,
2281 size_t local_symbol_count,
2282 const unsigned char* plocal_symbols,
2283 Relocatable_relocs*);
2285 // Relocate a section during a relocatable link.
2286 void
2287 relocate_for_relocatable(const Relocate_info<32, big_endian>*,
2288 unsigned int sh_type,
2289 const unsigned char* prelocs,
2290 size_t reloc_count,
2291 Output_section* output_section,
2292 off_t offset_in_output_section,
2293 const Relocatable_relocs*,
2294 unsigned char* view,
2295 Arm_address view_address,
2296 section_size_type view_size,
2297 unsigned char* reloc_view,
2298 section_size_type reloc_view_size);
2300 // Perform target-specific processing in a relocatable link. This is
2301 // only used if we use the relocation strategy RELOC_SPECIAL.
2302 void
2303 relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2304 unsigned int sh_type,
2305 const unsigned char* preloc_in,
2306 size_t relnum,
2307 Output_section* output_section,
2308 off_t offset_in_output_section,
2309 unsigned char* view,
2310 typename elfcpp::Elf_types<32>::Elf_Addr
2311 view_address,
2312 section_size_type view_size,
2313 unsigned char* preloc_out);
2315 // Return whether SYM is defined by the ABI.
2316 bool
2317 do_is_defined_by_abi(Symbol* sym) const
2318 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2320 // Return whether there is a GOT section.
2321 bool
2322 has_got_section() const
2323 { return this->got_ != NULL; }
2325 // Return the size of the GOT section.
2326 section_size_type
2327 got_size() const
2329 gold_assert(this->got_ != NULL);
2330 return this->got_->data_size();
2333 // Return the number of entries in the GOT.
2334 unsigned int
2335 got_entry_count() const
2337 if (!this->has_got_section())
2338 return 0;
2339 return this->got_size() / 4;
2342 // Return the number of entries in the PLT.
2343 unsigned int
2344 plt_entry_count() const;
2346 // Return the offset of the first non-reserved PLT entry.
2347 unsigned int
2348 first_plt_entry_offset() const;
2350 // Return the size of each PLT entry.
2351 unsigned int
2352 plt_entry_size() const;
2354 // Map platform-specific reloc types
2355 static unsigned int
2356 get_real_reloc_type(unsigned int r_type);
2359 // Methods to support stub-generations.
2362 // Return the stub factory
2363 const Stub_factory&
2364 stub_factory() const
2365 { return this->stub_factory_; }
2367 // Make a new Arm_input_section object.
2368 Arm_input_section<big_endian>*
2369 new_arm_input_section(Relobj*, unsigned int);
2371 // Find the Arm_input_section object corresponding to the SHNDX-th input
2372 // section of RELOBJ.
2373 Arm_input_section<big_endian>*
2374 find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2376 // Make a new Stub_table
2377 Stub_table<big_endian>*
2378 new_stub_table(Arm_input_section<big_endian>*);
2380 // Scan a section for stub generation.
2381 void
2382 scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2383 const unsigned char*, size_t, Output_section*,
2384 bool, const unsigned char*, Arm_address,
2385 section_size_type);
2387 // Relocate a stub.
2388 void
2389 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2390 Output_section*, unsigned char*, Arm_address,
2391 section_size_type);
2393 // Get the default ARM target.
2394 static Target_arm<big_endian>*
2395 default_target()
2397 gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2398 && parameters->target().is_big_endian() == big_endian);
2399 return static_cast<Target_arm<big_endian>*>(
2400 parameters->sized_target<32, big_endian>());
2403 // Whether NAME belongs to a mapping symbol.
2404 static bool
2405 is_mapping_symbol_name(const char* name)
2407 return (name
2408 && name[0] == '$'
2409 && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2410 && (name[2] == '\0' || name[2] == '.'));
2413 // Whether we work around the Cortex-A8 erratum.
2414 bool
2415 fix_cortex_a8() const
2416 { return this->fix_cortex_a8_; }
2418 // Whether we merge exidx entries in debuginfo.
2419 bool
2420 merge_exidx_entries() const
2421 { return parameters->options().merge_exidx_entries(); }
2423 // Whether we fix R_ARM_V4BX relocation.
2424 // 0 - do not fix
2425 // 1 - replace with MOV instruction (armv4 target)
2426 // 2 - make interworking veneer (>= armv4t targets only)
2427 General_options::Fix_v4bx
2428 fix_v4bx() const
2429 { return parameters->options().fix_v4bx(); }
2431 // Scan a span of THUMB code section for Cortex-A8 erratum.
2432 void
2433 scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2434 section_size_type, section_size_type,
2435 const unsigned char*, Arm_address);
2437 // Apply Cortex-A8 workaround to a branch.
2438 void
2439 apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2440 unsigned char*, Arm_address);
2442 protected:
2443 // Make an ELF object.
2444 Object*
2445 do_make_elf_object(const std::string&, Input_file*, off_t,
2446 const elfcpp::Ehdr<32, big_endian>& ehdr);
2448 Object*
2449 do_make_elf_object(const std::string&, Input_file*, off_t,
2450 const elfcpp::Ehdr<32, !big_endian>&)
2451 { gold_unreachable(); }
2453 Object*
2454 do_make_elf_object(const std::string&, Input_file*, off_t,
2455 const elfcpp::Ehdr<64, false>&)
2456 { gold_unreachable(); }
2458 Object*
2459 do_make_elf_object(const std::string&, Input_file*, off_t,
2460 const elfcpp::Ehdr<64, true>&)
2461 { gold_unreachable(); }
2463 // Make an output section.
2464 Output_section*
2465 do_make_output_section(const char* name, elfcpp::Elf_Word type,
2466 elfcpp::Elf_Xword flags)
2467 { return new Arm_output_section<big_endian>(name, type, flags); }
2469 void
2470 do_adjust_elf_header(unsigned char* view, int len) const;
2472 // We only need to generate stubs, and hence perform relaxation if we are
2473 // not doing relocatable linking.
2474 bool
2475 do_may_relax() const
2476 { return !parameters->options().relocatable(); }
2478 bool
2479 do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
2481 // Determine whether an object attribute tag takes an integer, a
2482 // string or both.
2484 do_attribute_arg_type(int tag) const;
2486 // Reorder tags during output.
2488 do_attributes_order(int num) const;
2490 // This is called when the target is selected as the default.
2491 void
2492 do_select_as_default_target()
2494 // No locking is required since there should only be one default target.
2495 // We cannot have both the big-endian and little-endian ARM targets
2496 // as the default.
2497 gold_assert(arm_reloc_property_table == NULL);
2498 arm_reloc_property_table = new Arm_reloc_property_table();
2501 // Virtual function which is set to return true by a target if
2502 // it can use relocation types to determine if a function's
2503 // pointer is taken.
2504 virtual bool
2505 do_can_check_for_function_pointers() const
2506 { return true; }
2508 // Whether a section called SECTION_NAME may have function pointers to
2509 // sections not eligible for safe ICF folding.
2510 virtual bool
2511 do_section_may_have_icf_unsafe_pointers(const char* section_name) const
2513 return (!is_prefix_of(".ARM.exidx", section_name)
2514 && !is_prefix_of(".ARM.extab", section_name)
2515 && Target::do_section_may_have_icf_unsafe_pointers(section_name));
2518 private:
2519 // The class which scans relocations.
2520 class Scan
2522 public:
2523 Scan()
2524 : issued_non_pic_error_(false)
2527 static inline int
2528 get_reference_flags(unsigned int r_type);
2530 inline void
2531 local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2532 Sized_relobj_file<32, big_endian>* object,
2533 unsigned int data_shndx,
2534 Output_section* output_section,
2535 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2536 const elfcpp::Sym<32, big_endian>& lsym);
2538 inline void
2539 global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2540 Sized_relobj_file<32, big_endian>* object,
2541 unsigned int data_shndx,
2542 Output_section* output_section,
2543 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2544 Symbol* gsym);
2546 inline bool
2547 local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2548 Sized_relobj_file<32, big_endian>* ,
2549 unsigned int ,
2550 Output_section* ,
2551 const elfcpp::Rel<32, big_endian>& ,
2552 unsigned int ,
2553 const elfcpp::Sym<32, big_endian>&);
2555 inline bool
2556 global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2557 Sized_relobj_file<32, big_endian>* ,
2558 unsigned int ,
2559 Output_section* ,
2560 const elfcpp::Rel<32, big_endian>& ,
2561 unsigned int , Symbol*);
2563 private:
2564 static void
2565 unsupported_reloc_local(Sized_relobj_file<32, big_endian>*,
2566 unsigned int r_type);
2568 static void
2569 unsupported_reloc_global(Sized_relobj_file<32, big_endian>*,
2570 unsigned int r_type, Symbol*);
2572 void
2573 check_non_pic(Relobj*, unsigned int r_type);
2575 // Almost identical to Symbol::needs_plt_entry except that it also
2576 // handles STT_ARM_TFUNC.
2577 static bool
2578 symbol_needs_plt_entry(const Symbol* sym)
2580 // An undefined symbol from an executable does not need a PLT entry.
2581 if (sym->is_undefined() && !parameters->options().shared())
2582 return false;
2584 return (!parameters->doing_static_link()
2585 && (sym->type() == elfcpp::STT_FUNC
2586 || sym->type() == elfcpp::STT_ARM_TFUNC)
2587 && (sym->is_from_dynobj()
2588 || sym->is_undefined()
2589 || sym->is_preemptible()));
2592 inline bool
2593 possible_function_pointer_reloc(unsigned int r_type);
2595 // Whether we have issued an error about a non-PIC compilation.
2596 bool issued_non_pic_error_;
2599 // The class which implements relocation.
2600 class Relocate
2602 public:
2603 Relocate()
2606 ~Relocate()
2609 // Return whether the static relocation needs to be applied.
2610 inline bool
2611 should_apply_static_reloc(const Sized_symbol<32>* gsym,
2612 unsigned int r_type,
2613 bool is_32bit,
2614 Output_section* output_section);
2616 // Do a relocation. Return false if the caller should not issue
2617 // any warnings about this relocation.
2618 inline bool
2619 relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2620 Output_section*, size_t relnum,
2621 const elfcpp::Rel<32, big_endian>&,
2622 unsigned int r_type, const Sized_symbol<32>*,
2623 const Symbol_value<32>*,
2624 unsigned char*, Arm_address,
2625 section_size_type);
2627 // Return whether we want to pass flag NON_PIC_REF for this
2628 // reloc. This means the relocation type accesses a symbol not via
2629 // GOT or PLT.
2630 static inline bool
2631 reloc_is_non_pic(unsigned int r_type)
2633 switch (r_type)
2635 // These relocation types reference GOT or PLT entries explicitly.
2636 case elfcpp::R_ARM_GOT_BREL:
2637 case elfcpp::R_ARM_GOT_ABS:
2638 case elfcpp::R_ARM_GOT_PREL:
2639 case elfcpp::R_ARM_GOT_BREL12:
2640 case elfcpp::R_ARM_PLT32_ABS:
2641 case elfcpp::R_ARM_TLS_GD32:
2642 case elfcpp::R_ARM_TLS_LDM32:
2643 case elfcpp::R_ARM_TLS_IE32:
2644 case elfcpp::R_ARM_TLS_IE12GP:
2646 // These relocate types may use PLT entries.
2647 case elfcpp::R_ARM_CALL:
2648 case elfcpp::R_ARM_THM_CALL:
2649 case elfcpp::R_ARM_JUMP24:
2650 case elfcpp::R_ARM_THM_JUMP24:
2651 case elfcpp::R_ARM_THM_JUMP19:
2652 case elfcpp::R_ARM_PLT32:
2653 case elfcpp::R_ARM_THM_XPC22:
2654 case elfcpp::R_ARM_PREL31:
2655 case elfcpp::R_ARM_SBREL31:
2656 return false;
2658 default:
2659 return true;
2663 private:
2664 // Do a TLS relocation.
2665 inline typename Arm_relocate_functions<big_endian>::Status
2666 relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2667 size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2668 const Sized_symbol<32>*, const Symbol_value<32>*,
2669 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2670 section_size_type);
2674 // A class which returns the size required for a relocation type,
2675 // used while scanning relocs during a relocatable link.
2676 class Relocatable_size_for_reloc
2678 public:
2679 unsigned int
2680 get_size_for_reloc(unsigned int, Relobj*);
2683 // Adjust TLS relocation type based on the options and whether this
2684 // is a local symbol.
2685 static tls::Tls_optimization
2686 optimize_tls_reloc(bool is_final, int r_type);
2688 // Get the GOT section, creating it if necessary.
2689 Arm_output_data_got<big_endian>*
2690 got_section(Symbol_table*, Layout*);
2692 // Get the GOT PLT section.
2693 Output_data_space*
2694 got_plt_section() const
2696 gold_assert(this->got_plt_ != NULL);
2697 return this->got_plt_;
2700 // Create a PLT entry for a global symbol.
2701 void
2702 make_plt_entry(Symbol_table*, Layout*, Symbol*);
2704 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2705 void
2706 define_tls_base_symbol(Symbol_table*, Layout*);
2708 // Create a GOT entry for the TLS module index.
2709 unsigned int
2710 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2711 Sized_relobj_file<32, big_endian>* object);
2713 // Get the PLT section.
2714 const Output_data_plt_arm<big_endian>*
2715 plt_section() const
2717 gold_assert(this->plt_ != NULL);
2718 return this->plt_;
2721 // Get the dynamic reloc section, creating it if necessary.
2722 Reloc_section*
2723 rel_dyn_section(Layout*);
2725 // Get the section to use for TLS_DESC relocations.
2726 Reloc_section*
2727 rel_tls_desc_section(Layout*) const;
2729 // Return true if the symbol may need a COPY relocation.
2730 // References from an executable object to non-function symbols
2731 // defined in a dynamic object may need a COPY relocation.
2732 bool
2733 may_need_copy_reloc(Symbol* gsym)
2735 return (gsym->type() != elfcpp::STT_ARM_TFUNC
2736 && gsym->may_need_copy_reloc());
2739 // Add a potential copy relocation.
2740 void
2741 copy_reloc(Symbol_table* symtab, Layout* layout,
2742 Sized_relobj_file<32, big_endian>* object,
2743 unsigned int shndx, Output_section* output_section,
2744 Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2746 this->copy_relocs_.copy_reloc(symtab, layout,
2747 symtab->get_sized_symbol<32>(sym),
2748 object, shndx, output_section, reloc,
2749 this->rel_dyn_section(layout));
2752 // Whether two EABI versions are compatible.
2753 static bool
2754 are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2756 // Merge processor-specific flags from input object and those in the ELF
2757 // header of the output.
2758 void
2759 merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2761 // Get the secondary compatible architecture.
2762 static int
2763 get_secondary_compatible_arch(const Attributes_section_data*);
2765 // Set the secondary compatible architecture.
2766 static void
2767 set_secondary_compatible_arch(Attributes_section_data*, int);
2769 static int
2770 tag_cpu_arch_combine(const char*, int, int*, int, int);
2772 // Helper to print AEABI enum tag value.
2773 static std::string
2774 aeabi_enum_name(unsigned int);
2776 // Return string value for TAG_CPU_name.
2777 static std::string
2778 tag_cpu_name_value(unsigned int);
2780 // Merge object attributes from input object and those in the output.
2781 void
2782 merge_object_attributes(const char*, const Attributes_section_data*);
2784 // Helper to get an AEABI object attribute
2785 Object_attribute*
2786 get_aeabi_object_attribute(int tag) const
2788 Attributes_section_data* pasd = this->attributes_section_data_;
2789 gold_assert(pasd != NULL);
2790 Object_attribute* attr =
2791 pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2792 gold_assert(attr != NULL);
2793 return attr;
2797 // Methods to support stub-generations.
2800 // Group input sections for stub generation.
2801 void
2802 group_sections(Layout*, section_size_type, bool, const Task*);
2804 // Scan a relocation for stub generation.
2805 void
2806 scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2807 const Sized_symbol<32>*, unsigned int,
2808 const Symbol_value<32>*,
2809 elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2811 // Scan a relocation section for stub.
2812 template<int sh_type>
2813 void
2814 scan_reloc_section_for_stubs(
2815 const Relocate_info<32, big_endian>* relinfo,
2816 const unsigned char* prelocs,
2817 size_t reloc_count,
2818 Output_section* output_section,
2819 bool needs_special_offset_handling,
2820 const unsigned char* view,
2821 elfcpp::Elf_types<32>::Elf_Addr view_address,
2822 section_size_type);
2824 // Fix .ARM.exidx section coverage.
2825 void
2826 fix_exidx_coverage(Layout*, const Input_objects*,
2827 Arm_output_section<big_endian>*, Symbol_table*,
2828 const Task*);
2830 // Functors for STL set.
2831 struct output_section_address_less_than
2833 bool
2834 operator()(const Output_section* s1, const Output_section* s2) const
2835 { return s1->address() < s2->address(); }
2838 // Information about this specific target which we pass to the
2839 // general Target structure.
2840 static const Target::Target_info arm_info;
2842 // The types of GOT entries needed for this platform.
2843 // These values are exposed to the ABI in an incremental link.
2844 // Do not renumber existing values without changing the version
2845 // number of the .gnu_incremental_inputs section.
2846 enum Got_type
2848 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
2849 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
2850 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
2851 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
2852 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
2855 typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2857 // Map input section to Arm_input_section.
2858 typedef Unordered_map<Section_id,
2859 Arm_input_section<big_endian>*,
2860 Section_id_hash>
2861 Arm_input_section_map;
2863 // Map output addresses to relocs for Cortex-A8 erratum.
2864 typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2865 Cortex_a8_relocs_info;
2867 // The GOT section.
2868 Arm_output_data_got<big_endian>* got_;
2869 // The PLT section.
2870 Output_data_plt_arm<big_endian>* plt_;
2871 // The GOT PLT section.
2872 Output_data_space* got_plt_;
2873 // The dynamic reloc section.
2874 Reloc_section* rel_dyn_;
2875 // Relocs saved to avoid a COPY reloc.
2876 Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2877 // Space for variables copied with a COPY reloc.
2878 Output_data_space* dynbss_;
2879 // Offset of the GOT entry for the TLS module index.
2880 unsigned int got_mod_index_offset_;
2881 // True if the _TLS_MODULE_BASE_ symbol has been defined.
2882 bool tls_base_symbol_defined_;
2883 // Vector of Stub_tables created.
2884 Stub_table_list stub_tables_;
2885 // Stub factory.
2886 const Stub_factory &stub_factory_;
2887 // Whether we force PIC branch veneers.
2888 bool should_force_pic_veneer_;
2889 // Map for locating Arm_input_sections.
2890 Arm_input_section_map arm_input_section_map_;
2891 // Attributes section data in output.
2892 Attributes_section_data* attributes_section_data_;
2893 // Whether we want to fix code for Cortex-A8 erratum.
2894 bool fix_cortex_a8_;
2895 // Map addresses to relocs for Cortex-A8 erratum.
2896 Cortex_a8_relocs_info cortex_a8_relocs_info_;
2899 template<bool big_endian>
2900 const Target::Target_info Target_arm<big_endian>::arm_info =
2902 32, // size
2903 big_endian, // is_big_endian
2904 elfcpp::EM_ARM, // machine_code
2905 false, // has_make_symbol
2906 false, // has_resolve
2907 false, // has_code_fill
2908 true, // is_default_stack_executable
2909 false, // can_icf_inline_merge_sections
2910 '\0', // wrap_char
2911 "/usr/lib/libc.so.1", // dynamic_linker
2912 0x8000, // default_text_segment_address
2913 0x1000, // abi_pagesize (overridable by -z max-page-size)
2914 0x1000, // common_pagesize (overridable by -z common-page-size)
2915 elfcpp::SHN_UNDEF, // small_common_shndx
2916 elfcpp::SHN_UNDEF, // large_common_shndx
2917 0, // small_common_section_flags
2918 0, // large_common_section_flags
2919 ".ARM.attributes", // attributes_section
2920 "aeabi" // attributes_vendor
2923 // Arm relocate functions class
2926 template<bool big_endian>
2927 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2929 public:
2930 typedef enum
2932 STATUS_OKAY, // No error during relocation.
2933 STATUS_OVERFLOW, // Relocation overflow.
2934 STATUS_BAD_RELOC // Relocation cannot be applied.
2935 } Status;
2937 private:
2938 typedef Relocate_functions<32, big_endian> Base;
2939 typedef Arm_relocate_functions<big_endian> This;
2941 // Encoding of imm16 argument for movt and movw ARM instructions
2942 // from ARM ARM:
2944 // imm16 := imm4 | imm12
2946 // 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
2947 // +-------+---------------+-------+-------+-----------------------+
2948 // | | |imm4 | |imm12 |
2949 // +-------+---------------+-------+-------+-----------------------+
2951 // Extract the relocation addend from VAL based on the ARM
2952 // instruction encoding described above.
2953 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2954 extract_arm_movw_movt_addend(
2955 typename elfcpp::Swap<32, big_endian>::Valtype val)
2957 // According to the Elf ABI for ARM Architecture the immediate
2958 // field is sign-extended to form the addend.
2959 return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff));
2962 // Insert X into VAL based on the ARM instruction encoding described
2963 // above.
2964 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2965 insert_val_arm_movw_movt(
2966 typename elfcpp::Swap<32, big_endian>::Valtype val,
2967 typename elfcpp::Swap<32, big_endian>::Valtype x)
2969 val &= 0xfff0f000;
2970 val |= x & 0x0fff;
2971 val |= (x & 0xf000) << 4;
2972 return val;
2975 // Encoding of imm16 argument for movt and movw Thumb2 instructions
2976 // from ARM ARM:
2978 // imm16 := imm4 | i | imm3 | imm8
2980 // 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
2981 // +---------+-+-----------+-------++-+-----+-------+---------------+
2982 // | |i| |imm4 || |imm3 | |imm8 |
2983 // +---------+-+-----------+-------++-+-----+-------+---------------+
2985 // Extract the relocation addend from VAL based on the Thumb2
2986 // instruction encoding described above.
2987 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2988 extract_thumb_movw_movt_addend(
2989 typename elfcpp::Swap<32, big_endian>::Valtype val)
2991 // According to the Elf ABI for ARM Architecture the immediate
2992 // field is sign-extended to form the addend.
2993 return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
2994 | ((val >> 15) & 0x0800)
2995 | ((val >> 4) & 0x0700)
2996 | (val & 0x00ff));
2999 // Insert X into VAL based on the Thumb2 instruction encoding
3000 // described above.
3001 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3002 insert_val_thumb_movw_movt(
3003 typename elfcpp::Swap<32, big_endian>::Valtype val,
3004 typename elfcpp::Swap<32, big_endian>::Valtype x)
3006 val &= 0xfbf08f00;
3007 val |= (x & 0xf000) << 4;
3008 val |= (x & 0x0800) << 15;
3009 val |= (x & 0x0700) << 4;
3010 val |= (x & 0x00ff);
3011 return val;
3014 // Calculate the smallest constant Kn for the specified residual.
3015 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3016 static uint32_t
3017 calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3019 int32_t msb;
3021 if (residual == 0)
3022 return 0;
3023 // Determine the most significant bit in the residual and
3024 // align the resulting value to a 2-bit boundary.
3025 for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3027 // The desired shift is now (msb - 6), or zero, whichever
3028 // is the greater.
3029 return (((msb - 6) < 0) ? 0 : (msb - 6));
3032 // Calculate the final residual for the specified group index.
3033 // If the passed group index is less than zero, the method will return
3034 // the value of the specified residual without any change.
3035 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3036 static typename elfcpp::Swap<32, big_endian>::Valtype
3037 calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3038 const int group)
3040 for (int n = 0; n <= group; n++)
3042 // Calculate which part of the value to mask.
3043 uint32_t shift = calc_grp_kn(residual);
3044 // Calculate the residual for the next time around.
3045 residual &= ~(residual & (0xff << shift));
3048 return residual;
3051 // Calculate the value of Gn for the specified group index.
3052 // We return it in the form of an encoded constant-and-rotation.
3053 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3054 static typename elfcpp::Swap<32, big_endian>::Valtype
3055 calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3056 const int group)
3058 typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3059 uint32_t shift = 0;
3061 for (int n = 0; n <= group; n++)
3063 // Calculate which part of the value to mask.
3064 shift = calc_grp_kn(residual);
3065 // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3066 gn = residual & (0xff << shift);
3067 // Calculate the residual for the next time around.
3068 residual &= ~gn;
3070 // Return Gn in the form of an encoded constant-and-rotation.
3071 return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3074 public:
3075 // Handle ARM long branches.
3076 static typename This::Status
3077 arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3078 unsigned char*, const Sized_symbol<32>*,
3079 const Arm_relobj<big_endian>*, unsigned int,
3080 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3082 // Handle THUMB long branches.
3083 static typename This::Status
3084 thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3085 unsigned char*, const Sized_symbol<32>*,
3086 const Arm_relobj<big_endian>*, unsigned int,
3087 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3090 // Return the branch offset of a 32-bit THUMB branch.
3091 static inline int32_t
3092 thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3094 // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3095 // involving the J1 and J2 bits.
3096 uint32_t s = (upper_insn & (1U << 10)) >> 10;
3097 uint32_t upper = upper_insn & 0x3ffU;
3098 uint32_t lower = lower_insn & 0x7ffU;
3099 uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3100 uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3101 uint32_t i1 = j1 ^ s ? 0 : 1;
3102 uint32_t i2 = j2 ^ s ? 0 : 1;
3104 return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3105 | (upper << 12) | (lower << 1));
3108 // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3109 // UPPER_INSN is the original upper instruction of the branch. Caller is
3110 // responsible for overflow checking and BLX offset adjustment.
3111 static inline uint16_t
3112 thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3114 uint32_t s = offset < 0 ? 1 : 0;
3115 uint32_t bits = static_cast<uint32_t>(offset);
3116 return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3119 // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3120 // LOWER_INSN is the original lower instruction of the branch. Caller is
3121 // responsible for overflow checking and BLX offset adjustment.
3122 static inline uint16_t
3123 thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3125 uint32_t s = offset < 0 ? 1 : 0;
3126 uint32_t bits = static_cast<uint32_t>(offset);
3127 return ((lower_insn & ~0x2fffU)
3128 | ((((bits >> 23) & 1) ^ !s) << 13)
3129 | ((((bits >> 22) & 1) ^ !s) << 11)
3130 | ((bits >> 1) & 0x7ffU));
3133 // Return the branch offset of a 32-bit THUMB conditional branch.
3134 static inline int32_t
3135 thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3137 uint32_t s = (upper_insn & 0x0400U) >> 10;
3138 uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3139 uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3140 uint32_t lower = (lower_insn & 0x07ffU);
3141 uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3143 return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3146 // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3147 // instruction. UPPER_INSN is the original upper instruction of the branch.
3148 // Caller is responsible for overflow checking.
3149 static inline uint16_t
3150 thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3152 uint32_t s = offset < 0 ? 1 : 0;
3153 uint32_t bits = static_cast<uint32_t>(offset);
3154 return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3157 // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3158 // instruction. LOWER_INSN is the original lower instruction of the branch.
3159 // The caller is responsible for overflow checking.
3160 static inline uint16_t
3161 thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3163 uint32_t bits = static_cast<uint32_t>(offset);
3164 uint32_t j2 = (bits & 0x00080000U) >> 19;
3165 uint32_t j1 = (bits & 0x00040000U) >> 18;
3166 uint32_t lo = (bits & 0x00000ffeU) >> 1;
3168 return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3171 // R_ARM_ABS8: S + A
3172 static inline typename This::Status
3173 abs8(unsigned char* view,
3174 const Sized_relobj_file<32, big_endian>* object,
3175 const Symbol_value<32>* psymval)
3177 typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3178 Valtype* wv = reinterpret_cast<Valtype*>(view);
3179 Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3180 int32_t addend = Bits<8>::sign_extend32(val);
3181 Arm_address x = psymval->value(object, addend);
3182 val = Bits<32>::bit_select32(val, x, 0xffU);
3183 elfcpp::Swap<8, big_endian>::writeval(wv, val);
3185 // R_ARM_ABS8 permits signed or unsigned results.
3186 return (Bits<8>::has_signed_unsigned_overflow32(x)
3187 ? This::STATUS_OVERFLOW
3188 : This::STATUS_OKAY);
3191 // R_ARM_THM_ABS5: S + A
3192 static inline typename This::Status
3193 thm_abs5(unsigned char* view,
3194 const Sized_relobj_file<32, big_endian>* object,
3195 const Symbol_value<32>* psymval)
3197 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3198 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3199 Valtype* wv = reinterpret_cast<Valtype*>(view);
3200 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3201 Reltype addend = (val & 0x7e0U) >> 6;
3202 Reltype x = psymval->value(object, addend);
3203 val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3204 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3205 return (Bits<5>::has_overflow32(x)
3206 ? This::STATUS_OVERFLOW
3207 : This::STATUS_OKAY);
3210 // R_ARM_ABS12: S + A
3211 static inline typename This::Status
3212 abs12(unsigned char* view,
3213 const Sized_relobj_file<32, big_endian>* object,
3214 const Symbol_value<32>* psymval)
3216 typedef typename elfcpp::Swap<32, 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<32, big_endian>::readval(wv);
3220 Reltype addend = val & 0x0fffU;
3221 Reltype x = psymval->value(object, addend);
3222 val = Bits<32>::bit_select32(val, x, 0x0fffU);
3223 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3224 return (Bits<12>::has_overflow32(x)
3225 ? This::STATUS_OVERFLOW
3226 : This::STATUS_OKAY);
3229 // R_ARM_ABS16: S + A
3230 static inline typename This::Status
3231 abs16(unsigned char* view,
3232 const Sized_relobj_file<32, big_endian>* object,
3233 const Symbol_value<32>* psymval)
3235 typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
3236 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3237 Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view);
3238 int32_t addend = Bits<16>::sign_extend32(val);
3239 Arm_address x = psymval->value(object, addend);
3240 val = Bits<32>::bit_select32(val, x, 0xffffU);
3241 elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val);
3243 // R_ARM_ABS16 permits signed or unsigned results.
3244 return (Bits<16>::has_signed_unsigned_overflow32(x)
3245 ? This::STATUS_OVERFLOW
3246 : This::STATUS_OKAY);
3249 // R_ARM_ABS32: (S + A) | T
3250 static inline typename This::Status
3251 abs32(unsigned char* view,
3252 const Sized_relobj_file<32, big_endian>* object,
3253 const Symbol_value<32>* psymval,
3254 Arm_address thumb_bit)
3256 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3257 Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3258 Valtype x = psymval->value(object, addend) | thumb_bit;
3259 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3260 return This::STATUS_OKAY;
3263 // R_ARM_REL32: (S + A) | T - P
3264 static inline typename This::Status
3265 rel32(unsigned char* view,
3266 const Sized_relobj_file<32, big_endian>* object,
3267 const Symbol_value<32>* psymval,
3268 Arm_address address,
3269 Arm_address thumb_bit)
3271 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3272 Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3273 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3274 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3275 return This::STATUS_OKAY;
3278 // R_ARM_THM_JUMP24: (S + A) | T - P
3279 static typename This::Status
3280 thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3281 const Symbol_value<32>* psymval, Arm_address address,
3282 Arm_address thumb_bit);
3284 // R_ARM_THM_JUMP6: S + A – P
3285 static inline typename This::Status
3286 thm_jump6(unsigned char* view,
3287 const Sized_relobj_file<32, big_endian>* object,
3288 const Symbol_value<32>* psymval,
3289 Arm_address address)
3291 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3292 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3293 Valtype* wv = reinterpret_cast<Valtype*>(view);
3294 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3295 // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3296 Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3297 Reltype x = (psymval->value(object, addend) - address);
3298 val = (val & 0xfd07) | ((x & 0x0040) << 3) | ((val & 0x003e) << 2);
3299 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3300 // CZB does only forward jumps.
3301 return ((x > 0x007e)
3302 ? This::STATUS_OVERFLOW
3303 : This::STATUS_OKAY);
3306 // R_ARM_THM_JUMP8: S + A – P
3307 static inline typename This::Status
3308 thm_jump8(unsigned char* view,
3309 const Sized_relobj_file<32, big_endian>* object,
3310 const Symbol_value<32>* psymval,
3311 Arm_address address)
3313 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3314 Valtype* wv = reinterpret_cast<Valtype*>(view);
3315 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3316 int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1);
3317 int32_t x = (psymval->value(object, addend) - address);
3318 elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00)
3319 | ((x & 0x01fe) >> 1)));
3320 // We do a 9-bit overflow check because x is right-shifted by 1 bit.
3321 return (Bits<9>::has_overflow32(x)
3322 ? This::STATUS_OVERFLOW
3323 : This::STATUS_OKAY);
3326 // R_ARM_THM_JUMP11: S + A – P
3327 static inline typename This::Status
3328 thm_jump11(unsigned char* view,
3329 const Sized_relobj_file<32, big_endian>* object,
3330 const Symbol_value<32>* psymval,
3331 Arm_address address)
3333 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3334 Valtype* wv = reinterpret_cast<Valtype*>(view);
3335 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3336 int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1);
3337 int32_t x = (psymval->value(object, addend) - address);
3338 elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800)
3339 | ((x & 0x0ffe) >> 1)));
3340 // We do a 12-bit overflow check because x is right-shifted by 1 bit.
3341 return (Bits<12>::has_overflow32(x)
3342 ? This::STATUS_OVERFLOW
3343 : This::STATUS_OKAY);
3346 // R_ARM_BASE_PREL: B(S) + A - P
3347 static inline typename This::Status
3348 base_prel(unsigned char* view,
3349 Arm_address origin,
3350 Arm_address address)
3352 Base::rel32(view, origin - address);
3353 return STATUS_OKAY;
3356 // R_ARM_BASE_ABS: B(S) + A
3357 static inline typename This::Status
3358 base_abs(unsigned char* view,
3359 Arm_address origin)
3361 Base::rel32(view, origin);
3362 return STATUS_OKAY;
3365 // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3366 static inline typename This::Status
3367 got_brel(unsigned char* view,
3368 typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3370 Base::rel32(view, got_offset);
3371 return This::STATUS_OKAY;
3374 // R_ARM_GOT_PREL: GOT(S) + A - P
3375 static inline typename This::Status
3376 got_prel(unsigned char* view,
3377 Arm_address got_entry,
3378 Arm_address address)
3380 Base::rel32(view, got_entry - address);
3381 return This::STATUS_OKAY;
3384 // R_ARM_PREL: (S + A) | T - P
3385 static inline typename This::Status
3386 prel31(unsigned char* view,
3387 const Sized_relobj_file<32, big_endian>* object,
3388 const Symbol_value<32>* psymval,
3389 Arm_address address,
3390 Arm_address thumb_bit)
3392 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3393 Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3394 Valtype addend = Bits<31>::sign_extend32(val);
3395 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3396 val = Bits<32>::bit_select32(val, x, 0x7fffffffU);
3397 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val);
3398 return (Bits<31>::has_overflow32(x)
3399 ? This::STATUS_OVERFLOW
3400 : This::STATUS_OKAY);
3403 // R_ARM_MOVW_ABS_NC: (S + A) | T (relative address base is )
3404 // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3405 // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3406 // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3407 static inline typename This::Status
3408 movw(unsigned char* view,
3409 const Sized_relobj_file<32, big_endian>* object,
3410 const Symbol_value<32>* psymval,
3411 Arm_address relative_address_base,
3412 Arm_address thumb_bit,
3413 bool check_overflow)
3415 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3416 Valtype* wv = reinterpret_cast<Valtype*>(view);
3417 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3418 Valtype addend = This::extract_arm_movw_movt_addend(val);
3419 Valtype x = ((psymval->value(object, addend) | thumb_bit)
3420 - relative_address_base);
3421 val = This::insert_val_arm_movw_movt(val, x);
3422 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3423 return ((check_overflow && Bits<16>::has_overflow32(x))
3424 ? This::STATUS_OVERFLOW
3425 : This::STATUS_OKAY);
3428 // R_ARM_MOVT_ABS: S + A (relative address base is 0)
3429 // R_ARM_MOVT_PREL: S + A - P
3430 // R_ARM_MOVT_BREL: S + A - B(S)
3431 static inline typename This::Status
3432 movt(unsigned char* view,
3433 const Sized_relobj_file<32, big_endian>* object,
3434 const Symbol_value<32>* psymval,
3435 Arm_address relative_address_base)
3437 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3438 Valtype* wv = reinterpret_cast<Valtype*>(view);
3439 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3440 Valtype addend = This::extract_arm_movw_movt_addend(val);
3441 Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3442 val = This::insert_val_arm_movw_movt(val, x);
3443 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3444 // FIXME: IHI0044D says that we should check for overflow.
3445 return This::STATUS_OKAY;
3448 // R_ARM_THM_MOVW_ABS_NC: S + A | T (relative_address_base is 0)
3449 // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3450 // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3451 // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3452 static inline typename This::Status
3453 thm_movw(unsigned char* view,
3454 const Sized_relobj_file<32, big_endian>* object,
3455 const Symbol_value<32>* psymval,
3456 Arm_address relative_address_base,
3457 Arm_address thumb_bit,
3458 bool check_overflow)
3460 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3461 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3462 Valtype* wv = reinterpret_cast<Valtype*>(view);
3463 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3464 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3465 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3466 Reltype x =
3467 (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3468 val = This::insert_val_thumb_movw_movt(val, x);
3469 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3470 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3471 return ((check_overflow && Bits<16>::has_overflow32(x))
3472 ? This::STATUS_OVERFLOW
3473 : This::STATUS_OKAY);
3476 // R_ARM_THM_MOVT_ABS: S + A (relative address base is 0)
3477 // R_ARM_THM_MOVT_PREL: S + A - P
3478 // R_ARM_THM_MOVT_BREL: S + A - B(S)
3479 static inline typename This::Status
3480 thm_movt(unsigned char* view,
3481 const Sized_relobj_file<32, big_endian>* object,
3482 const Symbol_value<32>* psymval,
3483 Arm_address relative_address_base)
3485 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3486 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3487 Valtype* wv = reinterpret_cast<Valtype*>(view);
3488 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3489 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3490 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3491 Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3492 val = This::insert_val_thumb_movw_movt(val, x);
3493 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3494 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3495 return This::STATUS_OKAY;
3498 // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3499 static inline typename This::Status
3500 thm_alu11(unsigned char* view,
3501 const Sized_relobj_file<32, big_endian>* object,
3502 const Symbol_value<32>* psymval,
3503 Arm_address address,
3504 Arm_address thumb_bit)
3506 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3507 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3508 Valtype* wv = reinterpret_cast<Valtype*>(view);
3509 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3510 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3512 // 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
3513 // -----------------------------------------------------------------------
3514 // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd |imm8
3515 // ADDW 1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd |imm8
3516 // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd |imm8
3517 // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd |imm8
3518 // SUBW 1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd |imm8
3519 // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd |imm8
3521 // Determine a sign for the addend.
3522 const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3523 || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3524 // Thumb2 addend encoding:
3525 // imm12 := i | imm3 | imm8
3526 int32_t addend = (insn & 0xff)
3527 | ((insn & 0x00007000) >> 4)
3528 | ((insn & 0x04000000) >> 15);
3529 // Apply a sign to the added.
3530 addend *= sign;
3532 int32_t x = (psymval->value(object, addend) | thumb_bit)
3533 - (address & 0xfffffffc);
3534 Reltype val = abs(x);
3535 // Mask out the value and a distinct part of the ADD/SUB opcode
3536 // (bits 7:5 of opword).
3537 insn = (insn & 0xfb0f8f00)
3538 | (val & 0xff)
3539 | ((val & 0x700) << 4)
3540 | ((val & 0x800) << 15);
3541 // Set the opcode according to whether the value to go in the
3542 // place is negative.
3543 if (x < 0)
3544 insn |= 0x00a00000;
3546 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3547 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3548 return ((val > 0xfff) ?
3549 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3552 // R_ARM_THM_PC8: S + A - Pa (Thumb)
3553 static inline typename This::Status
3554 thm_pc8(unsigned char* view,
3555 const Sized_relobj_file<32, big_endian>* object,
3556 const Symbol_value<32>* psymval,
3557 Arm_address address)
3559 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3560 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3561 Valtype* wv = reinterpret_cast<Valtype*>(view);
3562 Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3563 Reltype addend = ((insn & 0x00ff) << 2);
3564 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3565 Reltype val = abs(x);
3566 insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3568 elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3569 return ((val > 0x03fc)
3570 ? This::STATUS_OVERFLOW
3571 : This::STATUS_OKAY);
3574 // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3575 static inline typename This::Status
3576 thm_pc12(unsigned char* view,
3577 const Sized_relobj_file<32, big_endian>* object,
3578 const Symbol_value<32>* psymval,
3579 Arm_address address)
3581 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3582 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3583 Valtype* wv = reinterpret_cast<Valtype*>(view);
3584 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3585 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3586 // Determine a sign for the addend (positive if the U bit is 1).
3587 const int sign = (insn & 0x00800000) ? 1 : -1;
3588 int32_t addend = (insn & 0xfff);
3589 // Apply a sign to the added.
3590 addend *= sign;
3592 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3593 Reltype val = abs(x);
3594 // Mask out and apply the value and the U bit.
3595 insn = (insn & 0xff7ff000) | (val & 0xfff);
3596 // Set the U bit according to whether the value to go in the
3597 // place is positive.
3598 if (x >= 0)
3599 insn |= 0x00800000;
3601 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3602 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3603 return ((val > 0xfff) ?
3604 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3607 // R_ARM_V4BX
3608 static inline typename This::Status
3609 v4bx(const Relocate_info<32, big_endian>* relinfo,
3610 unsigned char* view,
3611 const Arm_relobj<big_endian>* object,
3612 const Arm_address address,
3613 const bool is_interworking)
3616 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3617 Valtype* wv = reinterpret_cast<Valtype*>(view);
3618 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3620 // Ensure that we have a BX instruction.
3621 gold_assert((val & 0x0ffffff0) == 0x012fff10);
3622 const uint32_t reg = (val & 0xf);
3623 if (is_interworking && reg != 0xf)
3625 Stub_table<big_endian>* stub_table =
3626 object->stub_table(relinfo->data_shndx);
3627 gold_assert(stub_table != NULL);
3629 Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3630 gold_assert(stub != NULL);
3632 int32_t veneer_address =
3633 stub_table->address() + stub->offset() - 8 - address;
3634 gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3635 && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3636 // Replace with a branch to veneer (B <addr>)
3637 val = (val & 0xf0000000) | 0x0a000000
3638 | ((veneer_address >> 2) & 0x00ffffff);
3640 else
3642 // Preserve Rm (lowest four bits) and the condition code
3643 // (highest four bits). Other bits encode MOV PC,Rm.
3644 val = (val & 0xf000000f) | 0x01a0f000;
3646 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3647 return This::STATUS_OKAY;
3650 // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3651 // R_ARM_ALU_PC_G0: ((S + A) | T) - P
3652 // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3653 // R_ARM_ALU_PC_G1: ((S + A) | T) - P
3654 // R_ARM_ALU_PC_G2: ((S + A) | T) - P
3655 // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3656 // R_ARM_ALU_SB_G0: ((S + A) | T) - B(S)
3657 // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3658 // R_ARM_ALU_SB_G1: ((S + A) | T) - B(S)
3659 // R_ARM_ALU_SB_G2: ((S + A) | T) - B(S)
3660 static inline typename This::Status
3661 arm_grp_alu(unsigned char* view,
3662 const Sized_relobj_file<32, big_endian>* object,
3663 const Symbol_value<32>* psymval,
3664 const int group,
3665 Arm_address address,
3666 Arm_address thumb_bit,
3667 bool check_overflow)
3669 gold_assert(group >= 0 && group < 3);
3670 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3671 Valtype* wv = reinterpret_cast<Valtype*>(view);
3672 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3674 // ALU group relocations are allowed only for the ADD/SUB instructions.
3675 // (0x00800000 - ADD, 0x00400000 - SUB)
3676 const Valtype opcode = insn & 0x01e00000;
3677 if (opcode != 0x00800000 && opcode != 0x00400000)
3678 return This::STATUS_BAD_RELOC;
3680 // Determine a sign for the addend.
3681 const int sign = (opcode == 0x00800000) ? 1 : -1;
3682 // shifter = rotate_imm * 2
3683 const uint32_t shifter = (insn & 0xf00) >> 7;
3684 // Initial addend value.
3685 int32_t addend = insn & 0xff;
3686 // Rotate addend right by shifter.
3687 addend = (addend >> shifter) | (addend << (32 - shifter));
3688 // Apply a sign to the added.
3689 addend *= sign;
3691 int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3692 Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3693 // Check for overflow if required
3694 if (check_overflow
3695 && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3696 return This::STATUS_OVERFLOW;
3698 // Mask out the value and the ADD/SUB part of the opcode; take care
3699 // not to destroy the S bit.
3700 insn &= 0xff1ff000;
3701 // Set the opcode according to whether the value to go in the
3702 // place is negative.
3703 insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3704 // Encode the offset (encoded Gn).
3705 insn |= gn;
3707 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3708 return This::STATUS_OKAY;
3711 // R_ARM_LDR_PC_G0: S + A - P
3712 // R_ARM_LDR_PC_G1: S + A - P
3713 // R_ARM_LDR_PC_G2: S + A - P
3714 // R_ARM_LDR_SB_G0: S + A - B(S)
3715 // R_ARM_LDR_SB_G1: S + A - B(S)
3716 // R_ARM_LDR_SB_G2: S + A - B(S)
3717 static inline typename This::Status
3718 arm_grp_ldr(unsigned char* view,
3719 const Sized_relobj_file<32, big_endian>* object,
3720 const Symbol_value<32>* psymval,
3721 const int group,
3722 Arm_address address)
3724 gold_assert(group >= 0 && group < 3);
3725 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3726 Valtype* wv = reinterpret_cast<Valtype*>(view);
3727 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3729 const int sign = (insn & 0x00800000) ? 1 : -1;
3730 int32_t addend = (insn & 0xfff) * sign;
3731 int32_t x = (psymval->value(object, addend) - address);
3732 // Calculate the relevant G(n-1) value to obtain this stage residual.
3733 Valtype residual =
3734 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3735 if (residual >= 0x1000)
3736 return This::STATUS_OVERFLOW;
3738 // Mask out the value and U bit.
3739 insn &= 0xff7ff000;
3740 // Set the U bit for non-negative values.
3741 if (x >= 0)
3742 insn |= 0x00800000;
3743 insn |= residual;
3745 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3746 return This::STATUS_OKAY;
3749 // R_ARM_LDRS_PC_G0: S + A - P
3750 // R_ARM_LDRS_PC_G1: S + A - P
3751 // R_ARM_LDRS_PC_G2: S + A - P
3752 // R_ARM_LDRS_SB_G0: S + A - B(S)
3753 // R_ARM_LDRS_SB_G1: S + A - B(S)
3754 // R_ARM_LDRS_SB_G2: S + A - B(S)
3755 static inline typename This::Status
3756 arm_grp_ldrs(unsigned char* view,
3757 const Sized_relobj_file<32, big_endian>* object,
3758 const Symbol_value<32>* psymval,
3759 const int group,
3760 Arm_address address)
3762 gold_assert(group >= 0 && group < 3);
3763 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3764 Valtype* wv = reinterpret_cast<Valtype*>(view);
3765 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3767 const int sign = (insn & 0x00800000) ? 1 : -1;
3768 int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3769 int32_t x = (psymval->value(object, addend) - address);
3770 // Calculate the relevant G(n-1) value to obtain this stage residual.
3771 Valtype residual =
3772 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3773 if (residual >= 0x100)
3774 return This::STATUS_OVERFLOW;
3776 // Mask out the value and U bit.
3777 insn &= 0xff7ff0f0;
3778 // Set the U bit for non-negative values.
3779 if (x >= 0)
3780 insn |= 0x00800000;
3781 insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3783 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3784 return This::STATUS_OKAY;
3787 // R_ARM_LDC_PC_G0: S + A - P
3788 // R_ARM_LDC_PC_G1: S + A - P
3789 // R_ARM_LDC_PC_G2: S + A - P
3790 // R_ARM_LDC_SB_G0: S + A - B(S)
3791 // R_ARM_LDC_SB_G1: S + A - B(S)
3792 // R_ARM_LDC_SB_G2: S + A - B(S)
3793 static inline typename This::Status
3794 arm_grp_ldc(unsigned char* view,
3795 const Sized_relobj_file<32, big_endian>* object,
3796 const Symbol_value<32>* psymval,
3797 const int group,
3798 Arm_address address)
3800 gold_assert(group >= 0 && group < 3);
3801 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3802 Valtype* wv = reinterpret_cast<Valtype*>(view);
3803 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3805 const int sign = (insn & 0x00800000) ? 1 : -1;
3806 int32_t addend = ((insn & 0xff) << 2) * sign;
3807 int32_t x = (psymval->value(object, addend) - address);
3808 // Calculate the relevant G(n-1) value to obtain this stage residual.
3809 Valtype residual =
3810 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3811 if ((residual & 0x3) != 0 || residual >= 0x400)
3812 return This::STATUS_OVERFLOW;
3814 // Mask out the value and U bit.
3815 insn &= 0xff7fff00;
3816 // Set the U bit for non-negative values.
3817 if (x >= 0)
3818 insn |= 0x00800000;
3819 insn |= (residual >> 2);
3821 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3822 return This::STATUS_OKAY;
3826 // Relocate ARM long branches. This handles relocation types
3827 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3828 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3829 // undefined and we do not use PLT in this relocation. In such a case,
3830 // the branch is converted into an NOP.
3832 template<bool big_endian>
3833 typename Arm_relocate_functions<big_endian>::Status
3834 Arm_relocate_functions<big_endian>::arm_branch_common(
3835 unsigned int r_type,
3836 const Relocate_info<32, big_endian>* relinfo,
3837 unsigned char* view,
3838 const Sized_symbol<32>* gsym,
3839 const Arm_relobj<big_endian>* object,
3840 unsigned int r_sym,
3841 const Symbol_value<32>* psymval,
3842 Arm_address address,
3843 Arm_address thumb_bit,
3844 bool is_weakly_undefined_without_plt)
3846 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3847 Valtype* wv = reinterpret_cast<Valtype*>(view);
3848 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3850 bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3851 && ((val & 0x0f000000UL) == 0x0a000000UL);
3852 bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3853 bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3854 && ((val & 0x0f000000UL) == 0x0b000000UL);
3855 bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3856 bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3858 // Check that the instruction is valid.
3859 if (r_type == elfcpp::R_ARM_CALL)
3861 if (!insn_is_uncond_bl && !insn_is_blx)
3862 return This::STATUS_BAD_RELOC;
3864 else if (r_type == elfcpp::R_ARM_JUMP24)
3866 if (!insn_is_b && !insn_is_cond_bl)
3867 return This::STATUS_BAD_RELOC;
3869 else if (r_type == elfcpp::R_ARM_PLT32)
3871 if (!insn_is_any_branch)
3872 return This::STATUS_BAD_RELOC;
3874 else if (r_type == elfcpp::R_ARM_XPC25)
3876 // FIXME: AAELF document IH0044C does not say much about it other
3877 // than it being obsolete.
3878 if (!insn_is_any_branch)
3879 return This::STATUS_BAD_RELOC;
3881 else
3882 gold_unreachable();
3884 // A branch to an undefined weak symbol is turned into a jump to
3885 // the next instruction unless a PLT entry will be created.
3886 // Do the same for local undefined symbols.
3887 // The jump to the next instruction is optimized as a NOP depending
3888 // on the architecture.
3889 const Target_arm<big_endian>* arm_target =
3890 Target_arm<big_endian>::default_target();
3891 if (is_weakly_undefined_without_plt)
3893 gold_assert(!parameters->options().relocatable());
3894 Valtype cond = val & 0xf0000000U;
3895 if (arm_target->may_use_arm_nop())
3896 val = cond | 0x0320f000;
3897 else
3898 val = cond | 0x01a00000; // Using pre-UAL nop: mov r0, r0.
3899 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3900 return This::STATUS_OKAY;
3903 Valtype addend = Bits<26>::sign_extend32(val << 2);
3904 Valtype branch_target = psymval->value(object, addend);
3905 int32_t branch_offset = branch_target - address;
3907 // We need a stub if the branch offset is too large or if we need
3908 // to switch mode.
3909 bool may_use_blx = arm_target->may_use_v5t_interworking();
3910 Reloc_stub* stub = NULL;
3912 if (!parameters->options().relocatable()
3913 && (Bits<26>::has_overflow32(branch_offset)
3914 || ((thumb_bit != 0)
3915 && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3917 Valtype unadjusted_branch_target = psymval->value(object, 0);
3919 Stub_type stub_type =
3920 Reloc_stub::stub_type_for_reloc(r_type, address,
3921 unadjusted_branch_target,
3922 (thumb_bit != 0));
3923 if (stub_type != arm_stub_none)
3925 Stub_table<big_endian>* stub_table =
3926 object->stub_table(relinfo->data_shndx);
3927 gold_assert(stub_table != NULL);
3929 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3930 stub = stub_table->find_reloc_stub(stub_key);
3931 gold_assert(stub != NULL);
3932 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3933 branch_target = stub_table->address() + stub->offset() + addend;
3934 branch_offset = branch_target - address;
3935 gold_assert(!Bits<26>::has_overflow32(branch_offset));
3939 // At this point, if we still need to switch mode, the instruction
3940 // must either be a BLX or a BL that can be converted to a BLX.
3941 if (thumb_bit != 0)
3943 // Turn BL to BLX.
3944 gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3945 val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3948 val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL);
3949 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3950 return (Bits<26>::has_overflow32(branch_offset)
3951 ? This::STATUS_OVERFLOW
3952 : This::STATUS_OKAY);
3955 // Relocate THUMB long branches. This handles relocation types
3956 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3957 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3958 // undefined and we do not use PLT in this relocation. In such a case,
3959 // the branch is converted into an NOP.
3961 template<bool big_endian>
3962 typename Arm_relocate_functions<big_endian>::Status
3963 Arm_relocate_functions<big_endian>::thumb_branch_common(
3964 unsigned int r_type,
3965 const Relocate_info<32, big_endian>* relinfo,
3966 unsigned char* view,
3967 const Sized_symbol<32>* gsym,
3968 const Arm_relobj<big_endian>* object,
3969 unsigned int r_sym,
3970 const Symbol_value<32>* psymval,
3971 Arm_address address,
3972 Arm_address thumb_bit,
3973 bool is_weakly_undefined_without_plt)
3975 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3976 Valtype* wv = reinterpret_cast<Valtype*>(view);
3977 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
3978 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
3980 // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
3981 // into account.
3982 bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
3983 bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
3985 // Check that the instruction is valid.
3986 if (r_type == elfcpp::R_ARM_THM_CALL)
3988 if (!is_bl_insn && !is_blx_insn)
3989 return This::STATUS_BAD_RELOC;
3991 else if (r_type == elfcpp::R_ARM_THM_JUMP24)
3993 // This cannot be a BLX.
3994 if (!is_bl_insn)
3995 return This::STATUS_BAD_RELOC;
3997 else if (r_type == elfcpp::R_ARM_THM_XPC22)
3999 // Check for Thumb to Thumb call.
4000 if (!is_blx_insn)
4001 return This::STATUS_BAD_RELOC;
4002 if (thumb_bit != 0)
4004 gold_warning(_("%s: Thumb BLX instruction targets "
4005 "thumb function '%s'."),
4006 object->name().c_str(),
4007 (gsym ? gsym->name() : "(local)"));
4008 // Convert BLX to BL.
4009 lower_insn |= 0x1000U;
4012 else
4013 gold_unreachable();
4015 // A branch to an undefined weak symbol is turned into a jump to
4016 // the next instruction unless a PLT entry will be created.
4017 // The jump to the next instruction is optimized as a NOP.W for
4018 // Thumb-2 enabled architectures.
4019 const Target_arm<big_endian>* arm_target =
4020 Target_arm<big_endian>::default_target();
4021 if (is_weakly_undefined_without_plt)
4023 gold_assert(!parameters->options().relocatable());
4024 if (arm_target->may_use_thumb2_nop())
4026 elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4027 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4029 else
4031 elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4032 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4034 return This::STATUS_OKAY;
4037 int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4038 Arm_address branch_target = psymval->value(object, addend);
4040 // For BLX, bit 1 of target address comes from bit 1 of base address.
4041 bool may_use_blx = arm_target->may_use_v5t_interworking();
4042 if (thumb_bit == 0 && may_use_blx)
4043 branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4045 int32_t branch_offset = branch_target - address;
4047 // We need a stub if the branch offset is too large or if we need
4048 // to switch mode.
4049 bool thumb2 = arm_target->using_thumb2();
4050 if (!parameters->options().relocatable()
4051 && ((!thumb2 && Bits<23>::has_overflow32(branch_offset))
4052 || (thumb2 && Bits<25>::has_overflow32(branch_offset))
4053 || ((thumb_bit == 0)
4054 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4055 || r_type == elfcpp::R_ARM_THM_JUMP24))))
4057 Arm_address unadjusted_branch_target = psymval->value(object, 0);
4059 Stub_type stub_type =
4060 Reloc_stub::stub_type_for_reloc(r_type, address,
4061 unadjusted_branch_target,
4062 (thumb_bit != 0));
4064 if (stub_type != arm_stub_none)
4066 Stub_table<big_endian>* stub_table =
4067 object->stub_table(relinfo->data_shndx);
4068 gold_assert(stub_table != NULL);
4070 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4071 Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4072 gold_assert(stub != NULL);
4073 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4074 branch_target = stub_table->address() + stub->offset() + addend;
4075 if (thumb_bit == 0 && may_use_blx)
4076 branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4077 branch_offset = branch_target - address;
4081 // At this point, if we still need to switch mode, the instruction
4082 // must either be a BLX or a BL that can be converted to a BLX.
4083 if (thumb_bit == 0)
4085 gold_assert(may_use_blx
4086 && (r_type == elfcpp::R_ARM_THM_CALL
4087 || r_type == elfcpp::R_ARM_THM_XPC22));
4088 // Make sure this is a BLX.
4089 lower_insn &= ~0x1000U;
4091 else
4093 // Make sure this is a BL.
4094 lower_insn |= 0x1000U;
4097 // For a BLX instruction, make sure that the relocation is rounded up
4098 // to a word boundary. This follows the semantics of the instruction
4099 // which specifies that bit 1 of the target address will come from bit
4100 // 1 of the base address.
4101 if ((lower_insn & 0x5000U) == 0x4000U)
4102 gold_assert((branch_offset & 3) == 0);
4104 // Put BRANCH_OFFSET back into the insn. Assumes two's complement.
4105 // We use the Thumb-2 encoding, which is safe even if dealing with
4106 // a Thumb-1 instruction by virtue of our overflow check above. */
4107 upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4108 lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4110 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4111 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4113 gold_assert(!Bits<25>::has_overflow32(branch_offset));
4115 return ((thumb2
4116 ? Bits<25>::has_overflow32(branch_offset)
4117 : Bits<23>::has_overflow32(branch_offset))
4118 ? This::STATUS_OVERFLOW
4119 : This::STATUS_OKAY);
4122 // Relocate THUMB-2 long conditional branches.
4123 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
4124 // undefined and we do not use PLT in this relocation. In such a case,
4125 // the branch is converted into an NOP.
4127 template<bool big_endian>
4128 typename Arm_relocate_functions<big_endian>::Status
4129 Arm_relocate_functions<big_endian>::thm_jump19(
4130 unsigned char* view,
4131 const Arm_relobj<big_endian>* object,
4132 const Symbol_value<32>* psymval,
4133 Arm_address address,
4134 Arm_address thumb_bit)
4136 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4137 Valtype* wv = reinterpret_cast<Valtype*>(view);
4138 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4139 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4140 int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4142 Arm_address branch_target = psymval->value(object, addend);
4143 int32_t branch_offset = branch_target - address;
4145 // ??? Should handle interworking? GCC might someday try to
4146 // use this for tail calls.
4147 // FIXME: We do support thumb entry to PLT yet.
4148 if (thumb_bit == 0)
4150 gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4151 return This::STATUS_BAD_RELOC;
4154 // Put RELOCATION back into the insn.
4155 upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4156 lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4158 // Put the relocated value back in the object file:
4159 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4160 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4162 return (Bits<21>::has_overflow32(branch_offset)
4163 ? This::STATUS_OVERFLOW
4164 : This::STATUS_OKAY);
4167 // Get the GOT section, creating it if necessary.
4169 template<bool big_endian>
4170 Arm_output_data_got<big_endian>*
4171 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4173 if (this->got_ == NULL)
4175 gold_assert(symtab != NULL && layout != NULL);
4177 this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4179 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4180 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4181 this->got_, ORDER_DATA, false);
4183 // The old GNU linker creates a .got.plt section. We just
4184 // create another set of data in the .got section. Note that we
4185 // always create a PLT if we create a GOT, although the PLT
4186 // might be empty.
4187 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4188 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4189 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4190 this->got_plt_, ORDER_DATA, false);
4192 // The first three entries are reserved.
4193 this->got_plt_->set_current_data_size(3 * 4);
4195 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4196 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4197 Symbol_table::PREDEFINED,
4198 this->got_plt_,
4199 0, 0, elfcpp::STT_OBJECT,
4200 elfcpp::STB_LOCAL,
4201 elfcpp::STV_HIDDEN, 0,
4202 false, false);
4204 return this->got_;
4207 // Get the dynamic reloc section, creating it if necessary.
4209 template<bool big_endian>
4210 typename Target_arm<big_endian>::Reloc_section*
4211 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4213 if (this->rel_dyn_ == NULL)
4215 gold_assert(layout != NULL);
4216 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4217 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4218 elfcpp::SHF_ALLOC, this->rel_dyn_,
4219 ORDER_DYNAMIC_RELOCS, false);
4221 return this->rel_dyn_;
4224 // Insn_template methods.
4226 // Return byte size of an instruction template.
4228 size_t
4229 Insn_template::size() const
4231 switch (this->type())
4233 case THUMB16_TYPE:
4234 case THUMB16_SPECIAL_TYPE:
4235 return 2;
4236 case ARM_TYPE:
4237 case THUMB32_TYPE:
4238 case DATA_TYPE:
4239 return 4;
4240 default:
4241 gold_unreachable();
4245 // Return alignment of an instruction template.
4247 unsigned
4248 Insn_template::alignment() const
4250 switch (this->type())
4252 case THUMB16_TYPE:
4253 case THUMB16_SPECIAL_TYPE:
4254 case THUMB32_TYPE:
4255 return 2;
4256 case ARM_TYPE:
4257 case DATA_TYPE:
4258 return 4;
4259 default:
4260 gold_unreachable();
4264 // Stub_template methods.
4266 Stub_template::Stub_template(
4267 Stub_type type, const Insn_template* insns,
4268 size_t insn_count)
4269 : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4270 entry_in_thumb_mode_(false), relocs_()
4272 off_t offset = 0;
4274 // Compute byte size and alignment of stub template.
4275 for (size_t i = 0; i < insn_count; i++)
4277 unsigned insn_alignment = insns[i].alignment();
4278 size_t insn_size = insns[i].size();
4279 gold_assert((offset & (insn_alignment - 1)) == 0);
4280 this->alignment_ = std::max(this->alignment_, insn_alignment);
4281 switch (insns[i].type())
4283 case Insn_template::THUMB16_TYPE:
4284 case Insn_template::THUMB16_SPECIAL_TYPE:
4285 if (i == 0)
4286 this->entry_in_thumb_mode_ = true;
4287 break;
4289 case Insn_template::THUMB32_TYPE:
4290 if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4291 this->relocs_.push_back(Reloc(i, offset));
4292 if (i == 0)
4293 this->entry_in_thumb_mode_ = true;
4294 break;
4296 case Insn_template::ARM_TYPE:
4297 // Handle cases where the target is encoded within the
4298 // instruction.
4299 if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4300 this->relocs_.push_back(Reloc(i, offset));
4301 break;
4303 case Insn_template::DATA_TYPE:
4304 // Entry point cannot be data.
4305 gold_assert(i != 0);
4306 this->relocs_.push_back(Reloc(i, offset));
4307 break;
4309 default:
4310 gold_unreachable();
4312 offset += insn_size;
4314 this->size_ = offset;
4317 // Stub methods.
4319 // Template to implement do_write for a specific target endianness.
4321 template<bool big_endian>
4322 void inline
4323 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4325 const Stub_template* stub_template = this->stub_template();
4326 const Insn_template* insns = stub_template->insns();
4328 // FIXME: We do not handle BE8 encoding yet.
4329 unsigned char* pov = view;
4330 for (size_t i = 0; i < stub_template->insn_count(); i++)
4332 switch (insns[i].type())
4334 case Insn_template::THUMB16_TYPE:
4335 elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4336 break;
4337 case Insn_template::THUMB16_SPECIAL_TYPE:
4338 elfcpp::Swap<16, big_endian>::writeval(
4339 pov,
4340 this->thumb16_special(i));
4341 break;
4342 case Insn_template::THUMB32_TYPE:
4344 uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4345 uint32_t lo = insns[i].data() & 0xffff;
4346 elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4347 elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4349 break;
4350 case Insn_template::ARM_TYPE:
4351 case Insn_template::DATA_TYPE:
4352 elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4353 break;
4354 default:
4355 gold_unreachable();
4357 pov += insns[i].size();
4359 gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4362 // Reloc_stub::Key methods.
4364 // Dump a Key as a string for debugging.
4366 std::string
4367 Reloc_stub::Key::name() const
4369 if (this->r_sym_ == invalid_index)
4371 // Global symbol key name
4372 // <stub-type>:<symbol name>:<addend>.
4373 const std::string sym_name = this->u_.symbol->name();
4374 // We need to print two hex number and two colons. So just add 100 bytes
4375 // to the symbol name size.
4376 size_t len = sym_name.size() + 100;
4377 char* buffer = new char[len];
4378 int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4379 sym_name.c_str(), this->addend_);
4380 gold_assert(c > 0 && c < static_cast<int>(len));
4381 delete[] buffer;
4382 return std::string(buffer);
4384 else
4386 // local symbol key name
4387 // <stub-type>:<object>:<r_sym>:<addend>.
4388 const size_t len = 200;
4389 char buffer[len];
4390 int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4391 this->u_.relobj, this->r_sym_, this->addend_);
4392 gold_assert(c > 0 && c < static_cast<int>(len));
4393 return std::string(buffer);
4397 // Reloc_stub methods.
4399 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4400 // LOCATION to DESTINATION.
4401 // This code is based on the arm_type_of_stub function in
4402 // bfd/elf32-arm.c. We have changed the interface a little to keep the Stub
4403 // class simple.
4405 Stub_type
4406 Reloc_stub::stub_type_for_reloc(
4407 unsigned int r_type,
4408 Arm_address location,
4409 Arm_address destination,
4410 bool target_is_thumb)
4412 Stub_type stub_type = arm_stub_none;
4414 // This is a bit ugly but we want to avoid using a templated class for
4415 // big and little endianities.
4416 bool may_use_blx;
4417 bool should_force_pic_veneer;
4418 bool thumb2;
4419 bool thumb_only;
4420 if (parameters->target().is_big_endian())
4422 const Target_arm<true>* big_endian_target =
4423 Target_arm<true>::default_target();
4424 may_use_blx = big_endian_target->may_use_v5t_interworking();
4425 should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4426 thumb2 = big_endian_target->using_thumb2();
4427 thumb_only = big_endian_target->using_thumb_only();
4429 else
4431 const Target_arm<false>* little_endian_target =
4432 Target_arm<false>::default_target();
4433 may_use_blx = little_endian_target->may_use_v5t_interworking();
4434 should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4435 thumb2 = little_endian_target->using_thumb2();
4436 thumb_only = little_endian_target->using_thumb_only();
4439 int64_t branch_offset;
4440 bool output_is_position_independent =
4441 parameters->options().output_is_position_independent();
4442 if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4444 // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4445 // base address (instruction address + 4).
4446 if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4447 destination = Bits<32>::bit_select32(destination, location, 0x2);
4448 branch_offset = static_cast<int64_t>(destination) - location;
4450 // Handle cases where:
4451 // - this call goes too far (different Thumb/Thumb2 max
4452 // distance)
4453 // - it's a Thumb->Arm call and blx is not available, or it's a
4454 // Thumb->Arm branch (not bl). A stub is needed in this case.
4455 if ((!thumb2
4456 && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4457 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4458 || (thumb2
4459 && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4460 || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4461 || ((!target_is_thumb)
4462 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4463 || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4465 if (target_is_thumb)
4467 // Thumb to thumb.
4468 if (!thumb_only)
4470 stub_type = (output_is_position_independent
4471 || should_force_pic_veneer)
4472 // PIC stubs.
4473 ? ((may_use_blx
4474 && (r_type == elfcpp::R_ARM_THM_CALL))
4475 // V5T and above. Stub starts with ARM code, so
4476 // we must be able to switch mode before
4477 // reaching it, which is only possible for 'bl'
4478 // (ie R_ARM_THM_CALL relocation).
4479 ? arm_stub_long_branch_any_thumb_pic
4480 // On V4T, use Thumb code only.
4481 : arm_stub_long_branch_v4t_thumb_thumb_pic)
4483 // non-PIC stubs.
4484 : ((may_use_blx
4485 && (r_type == elfcpp::R_ARM_THM_CALL))
4486 ? arm_stub_long_branch_any_any // V5T and above.
4487 : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4489 else
4491 stub_type = (output_is_position_independent
4492 || should_force_pic_veneer)
4493 ? arm_stub_long_branch_thumb_only_pic // PIC stub.
4494 : arm_stub_long_branch_thumb_only; // non-PIC stub.
4497 else
4499 // Thumb to arm.
4501 // FIXME: We should check that the input section is from an
4502 // object that has interwork enabled.
4504 stub_type = (output_is_position_independent
4505 || should_force_pic_veneer)
4506 // PIC stubs.
4507 ? ((may_use_blx
4508 && (r_type == elfcpp::R_ARM_THM_CALL))
4509 ? arm_stub_long_branch_any_arm_pic // V5T and above.
4510 : arm_stub_long_branch_v4t_thumb_arm_pic) // V4T.
4512 // non-PIC stubs.
4513 : ((may_use_blx
4514 && (r_type == elfcpp::R_ARM_THM_CALL))
4515 ? arm_stub_long_branch_any_any // V5T and above.
4516 : arm_stub_long_branch_v4t_thumb_arm); // V4T.
4518 // Handle v4t short branches.
4519 if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4520 && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4521 && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4522 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4526 else if (r_type == elfcpp::R_ARM_CALL
4527 || r_type == elfcpp::R_ARM_JUMP24
4528 || r_type == elfcpp::R_ARM_PLT32)
4530 branch_offset = static_cast<int64_t>(destination) - location;
4531 if (target_is_thumb)
4533 // Arm to thumb.
4535 // FIXME: We should check that the input section is from an
4536 // object that has interwork enabled.
4538 // We have an extra 2-bytes reach because of
4539 // the mode change (bit 24 (H) of BLX encoding).
4540 if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4541 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4542 || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4543 || (r_type == elfcpp::R_ARM_JUMP24)
4544 || (r_type == elfcpp::R_ARM_PLT32))
4546 stub_type = (output_is_position_independent
4547 || should_force_pic_veneer)
4548 // PIC stubs.
4549 ? (may_use_blx
4550 ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4551 : arm_stub_long_branch_v4t_arm_thumb_pic) // V4T stub.
4553 // non-PIC stubs.
4554 : (may_use_blx
4555 ? arm_stub_long_branch_any_any // V5T and above.
4556 : arm_stub_long_branch_v4t_arm_thumb); // V4T.
4559 else
4561 // Arm to arm.
4562 if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4563 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4565 stub_type = (output_is_position_independent
4566 || should_force_pic_veneer)
4567 ? arm_stub_long_branch_any_arm_pic // PIC stubs.
4568 : arm_stub_long_branch_any_any; /// non-PIC.
4573 return stub_type;
4576 // Cortex_a8_stub methods.
4578 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4579 // I is the position of the instruction template in the stub template.
4581 uint16_t
4582 Cortex_a8_stub::do_thumb16_special(size_t i)
4584 // The only use of this is to copy condition code from a conditional
4585 // branch being worked around to the corresponding conditional branch in
4586 // to the stub.
4587 gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4588 && i == 0);
4589 uint16_t data = this->stub_template()->insns()[i].data();
4590 gold_assert((data & 0xff00U) == 0xd000U);
4591 data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4592 return data;
4595 // Stub_factory methods.
4597 Stub_factory::Stub_factory()
4599 // The instruction template sequences are declared as static
4600 // objects and initialized first time the constructor runs.
4602 // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4603 // to reach the stub if necessary.
4604 static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4606 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4607 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4608 // dcd R_ARM_ABS32(X)
4611 // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4612 // available.
4613 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4615 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4616 Insn_template::arm_insn(0xe12fff1c), // bx ip
4617 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4618 // dcd R_ARM_ABS32(X)
4621 // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4622 static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4624 Insn_template::thumb16_insn(0xb401), // push {r0}
4625 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4626 Insn_template::thumb16_insn(0x4684), // mov ip, r0
4627 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4628 Insn_template::thumb16_insn(0x4760), // bx ip
4629 Insn_template::thumb16_insn(0xbf00), // nop
4630 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4631 // dcd R_ARM_ABS32(X)
4634 // V4T Thumb -> Thumb long branch stub. Using the stack is not
4635 // allowed.
4636 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4638 Insn_template::thumb16_insn(0x4778), // bx pc
4639 Insn_template::thumb16_insn(0x46c0), // nop
4640 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4641 Insn_template::arm_insn(0xe12fff1c), // bx ip
4642 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4643 // dcd R_ARM_ABS32(X)
4646 // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4647 // available.
4648 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4650 Insn_template::thumb16_insn(0x4778), // bx pc
4651 Insn_template::thumb16_insn(0x46c0), // nop
4652 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4653 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4654 // dcd R_ARM_ABS32(X)
4657 // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4658 // one, when the destination is close enough.
4659 static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4661 Insn_template::thumb16_insn(0x4778), // bx pc
4662 Insn_template::thumb16_insn(0x46c0), // nop
4663 Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8)
4666 // ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use
4667 // blx to reach the stub if necessary.
4668 static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4670 Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc]
4671 Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip
4672 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4673 // dcd R_ARM_REL32(X-4)
4676 // ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use
4677 // blx to reach the stub if necessary. We can not add into pc;
4678 // it is not guaranteed to mode switch (different in ARMv6 and
4679 // ARMv7).
4680 static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4682 Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4]
4683 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4684 Insn_template::arm_insn(0xe12fff1c), // bx ip
4685 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4686 // dcd R_ARM_REL32(X)
4689 // V4T ARM -> ARM long branch stub, PIC.
4690 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4692 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4693 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4694 Insn_template::arm_insn(0xe12fff1c), // bx ip
4695 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4696 // dcd R_ARM_REL32(X)
4699 // V4T Thumb -> ARM long branch stub, PIC.
4700 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4702 Insn_template::thumb16_insn(0x4778), // bx pc
4703 Insn_template::thumb16_insn(0x46c0), // nop
4704 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4705 Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc
4706 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4707 // dcd R_ARM_REL32(X)
4710 // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4711 // architectures.
4712 static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4714 Insn_template::thumb16_insn(0xb401), // push {r0}
4715 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4716 Insn_template::thumb16_insn(0x46fc), // mov ip, pc
4717 Insn_template::thumb16_insn(0x4484), // add ip, r0
4718 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4719 Insn_template::thumb16_insn(0x4760), // bx ip
4720 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4721 // dcd R_ARM_REL32(X)
4724 // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4725 // allowed.
4726 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4728 Insn_template::thumb16_insn(0x4778), // bx pc
4729 Insn_template::thumb16_insn(0x46c0), // nop
4730 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4731 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4732 Insn_template::arm_insn(0xe12fff1c), // bx ip
4733 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4734 // dcd R_ARM_REL32(X)
4737 // Cortex-A8 erratum-workaround stubs.
4739 // Stub used for conditional branches (which may be beyond +/-1MB away,
4740 // so we can't use a conditional branch to reach this stub).
4742 // original code:
4744 // b<cond> X
4745 // after:
4747 static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4749 Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true
4750 Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after
4751 Insn_template::thumb32_b_insn(0xf000b800, -4) // true:
4752 // b.w X
4755 // Stub used for b.w and bl.w instructions.
4757 static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4759 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4762 static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4764 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4767 // Stub used for Thumb-2 blx.w instructions. We modified the original blx.w
4768 // instruction (which switches to ARM mode) to point to this stub. Jump to
4769 // the real destination using an ARM-mode branch.
4770 static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4772 Insn_template::arm_rel_insn(0xea000000, -8) // b dest
4775 // Stub used to provide an interworking for R_ARM_V4BX relocation
4776 // (bx r[n] instruction).
4777 static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4779 Insn_template::arm_insn(0xe3100001), // tst r<n>, #1
4780 Insn_template::arm_insn(0x01a0f000), // moveq pc, r<n>
4781 Insn_template::arm_insn(0xe12fff10) // bx r<n>
4784 // Fill in the stub template look-up table. Stub templates are constructed
4785 // per instance of Stub_factory for fast look-up without locking
4786 // in a thread-enabled environment.
4788 this->stub_templates_[arm_stub_none] =
4789 new Stub_template(arm_stub_none, NULL, 0);
4791 #define DEF_STUB(x) \
4792 do \
4794 size_t array_size \
4795 = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4796 Stub_type type = arm_stub_##x; \
4797 this->stub_templates_[type] = \
4798 new Stub_template(type, elf32_arm_stub_##x, array_size); \
4800 while (0);
4802 DEF_STUBS
4803 #undef DEF_STUB
4806 // Stub_table methods.
4808 // Remove all Cortex-A8 stub.
4810 template<bool big_endian>
4811 void
4812 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4814 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4815 p != this->cortex_a8_stubs_.end();
4816 ++p)
4817 delete p->second;
4818 this->cortex_a8_stubs_.clear();
4821 // Relocate one stub. This is a helper for Stub_table::relocate_stubs().
4823 template<bool big_endian>
4824 void
4825 Stub_table<big_endian>::relocate_stub(
4826 Stub* stub,
4827 const Relocate_info<32, big_endian>* relinfo,
4828 Target_arm<big_endian>* arm_target,
4829 Output_section* output_section,
4830 unsigned char* view,
4831 Arm_address address,
4832 section_size_type view_size)
4834 const Stub_template* stub_template = stub->stub_template();
4835 if (stub_template->reloc_count() != 0)
4837 // Adjust view to cover the stub only.
4838 section_size_type offset = stub->offset();
4839 section_size_type stub_size = stub_template->size();
4840 gold_assert(offset + stub_size <= view_size);
4842 arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4843 address + offset, stub_size);
4847 // Relocate all stubs in this stub table.
4849 template<bool big_endian>
4850 void
4851 Stub_table<big_endian>::relocate_stubs(
4852 const Relocate_info<32, big_endian>* relinfo,
4853 Target_arm<big_endian>* arm_target,
4854 Output_section* output_section,
4855 unsigned char* view,
4856 Arm_address address,
4857 section_size_type view_size)
4859 // If we are passed a view bigger than the stub table's. we need to
4860 // adjust the view.
4861 gold_assert(address == this->address()
4862 && (view_size
4863 == static_cast<section_size_type>(this->data_size())));
4865 // Relocate all relocation stubs.
4866 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4867 p != this->reloc_stubs_.end();
4868 ++p)
4869 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4870 address, view_size);
4872 // Relocate all Cortex-A8 stubs.
4873 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4874 p != this->cortex_a8_stubs_.end();
4875 ++p)
4876 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4877 address, view_size);
4879 // Relocate all ARM V4BX stubs.
4880 for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4881 p != this->arm_v4bx_stubs_.end();
4882 ++p)
4884 if (*p != NULL)
4885 this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4886 address, view_size);
4890 // Write out the stubs to file.
4892 template<bool big_endian>
4893 void
4894 Stub_table<big_endian>::do_write(Output_file* of)
4896 off_t offset = this->offset();
4897 const section_size_type oview_size =
4898 convert_to_section_size_type(this->data_size());
4899 unsigned char* const oview = of->get_output_view(offset, oview_size);
4901 // Write relocation stubs.
4902 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4903 p != this->reloc_stubs_.end();
4904 ++p)
4906 Reloc_stub* stub = p->second;
4907 Arm_address address = this->address() + stub->offset();
4908 gold_assert(address
4909 == align_address(address,
4910 stub->stub_template()->alignment()));
4911 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4912 big_endian);
4915 // Write Cortex-A8 stubs.
4916 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4917 p != this->cortex_a8_stubs_.end();
4918 ++p)
4920 Cortex_a8_stub* stub = p->second;
4921 Arm_address address = this->address() + stub->offset();
4922 gold_assert(address
4923 == align_address(address,
4924 stub->stub_template()->alignment()));
4925 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4926 big_endian);
4929 // Write ARM V4BX relocation stubs.
4930 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4931 p != this->arm_v4bx_stubs_.end();
4932 ++p)
4934 if (*p == NULL)
4935 continue;
4937 Arm_address address = this->address() + (*p)->offset();
4938 gold_assert(address
4939 == align_address(address,
4940 (*p)->stub_template()->alignment()));
4941 (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4942 big_endian);
4945 of->write_output_view(this->offset(), oview_size, oview);
4948 // Update the data size and address alignment of the stub table at the end
4949 // of a relaxation pass. Return true if either the data size or the
4950 // alignment changed in this relaxation pass.
4952 template<bool big_endian>
4953 bool
4954 Stub_table<big_endian>::update_data_size_and_addralign()
4956 // Go over all stubs in table to compute data size and address alignment.
4957 off_t size = this->reloc_stubs_size_;
4958 unsigned addralign = this->reloc_stubs_addralign_;
4960 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4961 p != this->cortex_a8_stubs_.end();
4962 ++p)
4964 const Stub_template* stub_template = p->second->stub_template();
4965 addralign = std::max(addralign, stub_template->alignment());
4966 size = (align_address(size, stub_template->alignment())
4967 + stub_template->size());
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 const Stub_template* stub_template = (*p)->stub_template();
4978 addralign = std::max(addralign, stub_template->alignment());
4979 size = (align_address(size, stub_template->alignment())
4980 + stub_template->size());
4983 // Check if either data size or alignment changed in this pass.
4984 // Update prev_data_size_ and prev_addralign_. These will be used
4985 // as the current data size and address alignment for the next pass.
4986 bool changed = size != this->prev_data_size_;
4987 this->prev_data_size_ = size;
4989 if (addralign != this->prev_addralign_)
4990 changed = true;
4991 this->prev_addralign_ = addralign;
4993 return changed;
4996 // Finalize the stubs. This sets the offsets of the stubs within the stub
4997 // table. It also marks all input sections needing Cortex-A8 workaround.
4999 template<bool big_endian>
5000 void
5001 Stub_table<big_endian>::finalize_stubs()
5003 off_t off = this->reloc_stubs_size_;
5004 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5005 p != this->cortex_a8_stubs_.end();
5006 ++p)
5008 Cortex_a8_stub* stub = p->second;
5009 const Stub_template* stub_template = stub->stub_template();
5010 uint64_t stub_addralign = stub_template->alignment();
5011 off = align_address(off, stub_addralign);
5012 stub->set_offset(off);
5013 off += stub_template->size();
5015 // Mark input section so that we can determine later if a code section
5016 // needs the Cortex-A8 workaround quickly.
5017 Arm_relobj<big_endian>* arm_relobj =
5018 Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5019 arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5022 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5023 p != this->arm_v4bx_stubs_.end();
5024 ++p)
5026 if (*p == NULL)
5027 continue;
5029 const Stub_template* stub_template = (*p)->stub_template();
5030 uint64_t stub_addralign = stub_template->alignment();
5031 off = align_address(off, stub_addralign);
5032 (*p)->set_offset(off);
5033 off += stub_template->size();
5036 gold_assert(off <= this->prev_data_size_);
5039 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5040 // and VIEW_ADDRESS + VIEW_SIZE - 1. VIEW points to the mapped address
5041 // of the address range seen by the linker.
5043 template<bool big_endian>
5044 void
5045 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5046 Target_arm<big_endian>* arm_target,
5047 unsigned char* view,
5048 Arm_address view_address,
5049 section_size_type view_size)
5051 // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5052 for (Cortex_a8_stub_list::const_iterator p =
5053 this->cortex_a8_stubs_.lower_bound(view_address);
5054 ((p != this->cortex_a8_stubs_.end())
5055 && (p->first < (view_address + view_size)));
5056 ++p)
5058 // We do not store the THUMB bit in the LSB of either the branch address
5059 // or the stub offset. There is no need to strip the LSB.
5060 Arm_address branch_address = p->first;
5061 const Cortex_a8_stub* stub = p->second;
5062 Arm_address stub_address = this->address() + stub->offset();
5064 // Offset of the branch instruction relative to this view.
5065 section_size_type offset =
5066 convert_to_section_size_type(branch_address - view_address);
5067 gold_assert((offset + 4) <= view_size);
5069 arm_target->apply_cortex_a8_workaround(stub, stub_address,
5070 view + offset, branch_address);
5074 // Arm_input_section methods.
5076 // Initialize an Arm_input_section.
5078 template<bool big_endian>
5079 void
5080 Arm_input_section<big_endian>::init()
5082 Relobj* relobj = this->relobj();
5083 unsigned int shndx = this->shndx();
5085 // We have to cache original size, alignment and contents to avoid locking
5086 // the original file.
5087 this->original_addralign_ =
5088 convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5090 // This is not efficient but we expect only a small number of relaxed
5091 // input sections for stubs.
5092 section_size_type section_size;
5093 const unsigned char* section_contents =
5094 relobj->section_contents(shndx, &section_size, false);
5095 this->original_size_ =
5096 convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5098 gold_assert(this->original_contents_ == NULL);
5099 this->original_contents_ = new unsigned char[section_size];
5100 memcpy(this->original_contents_, section_contents, section_size);
5102 // We want to make this look like the original input section after
5103 // output sections are finalized.
5104 Output_section* os = relobj->output_section(shndx);
5105 off_t offset = relobj->output_section_offset(shndx);
5106 gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5107 this->set_address(os->address() + offset);
5108 this->set_file_offset(os->offset() + offset);
5110 this->set_current_data_size(this->original_size_);
5111 this->finalize_data_size();
5114 template<bool big_endian>
5115 void
5116 Arm_input_section<big_endian>::do_write(Output_file* of)
5118 // We have to write out the original section content.
5119 gold_assert(this->original_contents_ != NULL);
5120 of->write(this->offset(), this->original_contents_,
5121 this->original_size_);
5123 // If this owns a stub table and it is not empty, write it.
5124 if (this->is_stub_table_owner() && !this->stub_table_->empty())
5125 this->stub_table_->write(of);
5128 // Finalize data size.
5130 template<bool big_endian>
5131 void
5132 Arm_input_section<big_endian>::set_final_data_size()
5134 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5136 if (this->is_stub_table_owner())
5138 this->stub_table_->finalize_data_size();
5139 off = align_address(off, this->stub_table_->addralign());
5140 off += this->stub_table_->data_size();
5142 this->set_data_size(off);
5145 // Reset address and file offset.
5147 template<bool big_endian>
5148 void
5149 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5151 // Size of the original input section contents.
5152 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5154 // If this is a stub table owner, account for the stub table size.
5155 if (this->is_stub_table_owner())
5157 Stub_table<big_endian>* stub_table = this->stub_table_;
5159 // Reset the stub table's address and file offset. The
5160 // current data size for child will be updated after that.
5161 stub_table_->reset_address_and_file_offset();
5162 off = align_address(off, stub_table_->addralign());
5163 off += stub_table->current_data_size();
5166 this->set_current_data_size(off);
5169 // Arm_exidx_cantunwind methods.
5171 // Write this to Output file OF for a fixed endianness.
5173 template<bool big_endian>
5174 void
5175 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5177 off_t offset = this->offset();
5178 const section_size_type oview_size = 8;
5179 unsigned char* const oview = of->get_output_view(offset, oview_size);
5181 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
5183 Output_section* os = this->relobj_->output_section(this->shndx_);
5184 gold_assert(os != NULL);
5186 Arm_relobj<big_endian>* arm_relobj =
5187 Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5188 Arm_address output_offset =
5189 arm_relobj->get_output_section_offset(this->shndx_);
5190 Arm_address section_start;
5191 section_size_type section_size;
5193 // Find out the end of the text section referred by this.
5194 if (output_offset != Arm_relobj<big_endian>::invalid_address)
5196 section_start = os->address() + output_offset;
5197 const Arm_exidx_input_section* exidx_input_section =
5198 arm_relobj->exidx_input_section_by_link(this->shndx_);
5199 gold_assert(exidx_input_section != NULL);
5200 section_size =
5201 convert_to_section_size_type(exidx_input_section->text_size());
5203 else
5205 // Currently this only happens for a relaxed section.
5206 const Output_relaxed_input_section* poris =
5207 os->find_relaxed_input_section(this->relobj_, this->shndx_);
5208 gold_assert(poris != NULL);
5209 section_start = poris->address();
5210 section_size = convert_to_section_size_type(poris->data_size());
5213 // We always append this to the end of an EXIDX section.
5214 Arm_address output_address = section_start + section_size;
5216 // Write out the entry. The first word either points to the beginning
5217 // or after the end of a text section. The second word is the special
5218 // EXIDX_CANTUNWIND value.
5219 uint32_t prel31_offset = output_address - this->address();
5220 if (Bits<31>::has_overflow32(offset))
5221 gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5222 elfcpp::Swap_unaligned<32, big_endian>::writeval(oview,
5223 prel31_offset & 0x7fffffffU);
5224 elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4,
5225 elfcpp::EXIDX_CANTUNWIND);
5227 of->write_output_view(this->offset(), oview_size, oview);
5230 // Arm_exidx_merged_section methods.
5232 // Constructor for Arm_exidx_merged_section.
5233 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5234 // SECTION_OFFSET_MAP points to a section offset map describing how
5235 // parts of the input section are mapped to output. DELETED_BYTES is
5236 // the number of bytes deleted from the EXIDX input section.
5238 Arm_exidx_merged_section::Arm_exidx_merged_section(
5239 const Arm_exidx_input_section& exidx_input_section,
5240 const Arm_exidx_section_offset_map& section_offset_map,
5241 uint32_t deleted_bytes)
5242 : Output_relaxed_input_section(exidx_input_section.relobj(),
5243 exidx_input_section.shndx(),
5244 exidx_input_section.addralign()),
5245 exidx_input_section_(exidx_input_section),
5246 section_offset_map_(section_offset_map)
5248 // If we retain or discard the whole EXIDX input section, we would
5249 // not be here.
5250 gold_assert(deleted_bytes != 0
5251 && deleted_bytes != this->exidx_input_section_.size());
5253 // Fix size here so that we do not need to implement set_final_data_size.
5254 uint32_t size = exidx_input_section.size() - deleted_bytes;
5255 this->set_data_size(size);
5256 this->fix_data_size();
5258 // Allocate buffer for section contents and build contents.
5259 this->section_contents_ = new unsigned char[size];
5262 // Build the contents of a merged EXIDX output section.
5264 void
5265 Arm_exidx_merged_section::build_contents(
5266 const unsigned char* original_contents,
5267 section_size_type original_size)
5269 // Go over spans of input offsets and write only those that are not
5270 // discarded.
5271 section_offset_type in_start = 0;
5272 section_offset_type out_start = 0;
5273 section_offset_type in_max =
5274 convert_types<section_offset_type>(original_size);
5275 section_offset_type out_max =
5276 convert_types<section_offset_type>(this->data_size());
5277 for (Arm_exidx_section_offset_map::const_iterator p =
5278 this->section_offset_map_.begin();
5279 p != this->section_offset_map_.end();
5280 ++p)
5282 section_offset_type in_end = p->first;
5283 gold_assert(in_end >= in_start);
5284 section_offset_type out_end = p->second;
5285 size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5286 if (out_end != -1)
5288 size_t out_chunk_size =
5289 convert_types<size_t>(out_end - out_start + 1);
5291 gold_assert(out_chunk_size == in_chunk_size
5292 && in_end < in_max && out_end < out_max);
5294 memcpy(this->section_contents_ + out_start,
5295 original_contents + in_start,
5296 out_chunk_size);
5297 out_start += out_chunk_size;
5299 in_start += in_chunk_size;
5303 // Given an input OBJECT, an input section index SHNDX within that
5304 // object, and an OFFSET relative to the start of that input
5305 // section, return whether or not the corresponding offset within
5306 // the output section is known. If this function returns true, it
5307 // sets *POUTPUT to the output offset. The value -1 indicates that
5308 // this input offset is being discarded.
5310 bool
5311 Arm_exidx_merged_section::do_output_offset(
5312 const Relobj* relobj,
5313 unsigned int shndx,
5314 section_offset_type offset,
5315 section_offset_type* poutput) const
5317 // We only handle offsets for the original EXIDX input section.
5318 if (relobj != this->exidx_input_section_.relobj()
5319 || shndx != this->exidx_input_section_.shndx())
5320 return false;
5322 section_offset_type section_size =
5323 convert_types<section_offset_type>(this->exidx_input_section_.size());
5324 if (offset < 0 || offset >= section_size)
5325 // Input offset is out of valid range.
5326 *poutput = -1;
5327 else
5329 // We need to look up the section offset map to determine the output
5330 // offset. Find the reference point in map that is first offset
5331 // bigger than or equal to this offset.
5332 Arm_exidx_section_offset_map::const_iterator p =
5333 this->section_offset_map_.lower_bound(offset);
5335 // The section offset maps are build such that this should not happen if
5336 // input offset is in the valid range.
5337 gold_assert(p != this->section_offset_map_.end());
5339 // We need to check if this is dropped.
5340 section_offset_type ref = p->first;
5341 section_offset_type mapped_ref = p->second;
5343 if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5344 // Offset is present in output.
5345 *poutput = mapped_ref + (offset - ref);
5346 else
5347 // Offset is discarded owing to EXIDX entry merging.
5348 *poutput = -1;
5351 return true;
5354 // Write this to output file OF.
5356 void
5357 Arm_exidx_merged_section::do_write(Output_file* of)
5359 off_t offset = this->offset();
5360 const section_size_type oview_size = this->data_size();
5361 unsigned char* const oview = of->get_output_view(offset, oview_size);
5363 Output_section* os = this->relobj()->output_section(this->shndx());
5364 gold_assert(os != NULL);
5366 memcpy(oview, this->section_contents_, oview_size);
5367 of->write_output_view(this->offset(), oview_size, oview);
5370 // Arm_exidx_fixup methods.
5372 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5373 // is not an EXIDX_CANTUNWIND entry already. The new EXIDX_CANTUNWIND entry
5374 // points to the end of the last seen EXIDX section.
5376 void
5377 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5379 if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5380 && this->last_input_section_ != NULL)
5382 Relobj* relobj = this->last_input_section_->relobj();
5383 unsigned int text_shndx = this->last_input_section_->link();
5384 Arm_exidx_cantunwind* cantunwind =
5385 new Arm_exidx_cantunwind(relobj, text_shndx);
5386 this->exidx_output_section_->add_output_section_data(cantunwind);
5387 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5391 // Process an EXIDX section entry in input. Return whether this entry
5392 // can be deleted in the output. SECOND_WORD in the second word of the
5393 // EXIDX entry.
5395 bool
5396 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5398 bool delete_entry;
5399 if (second_word == elfcpp::EXIDX_CANTUNWIND)
5401 // Merge if previous entry is also an EXIDX_CANTUNWIND.
5402 delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5403 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5405 else if ((second_word & 0x80000000) != 0)
5407 // Inlined unwinding data. Merge if equal to previous.
5408 delete_entry = (merge_exidx_entries_
5409 && this->last_unwind_type_ == UT_INLINED_ENTRY
5410 && this->last_inlined_entry_ == second_word);
5411 this->last_unwind_type_ = UT_INLINED_ENTRY;
5412 this->last_inlined_entry_ = second_word;
5414 else
5416 // Normal table entry. In theory we could merge these too,
5417 // but duplicate entries are likely to be much less common.
5418 delete_entry = false;
5419 this->last_unwind_type_ = UT_NORMAL_ENTRY;
5421 return delete_entry;
5424 // Update the current section offset map during EXIDX section fix-up.
5425 // If there is no map, create one. INPUT_OFFSET is the offset of a
5426 // reference point, DELETED_BYTES is the number of deleted by in the
5427 // section so far. If DELETE_ENTRY is true, the reference point and
5428 // all offsets after the previous reference point are discarded.
5430 void
5431 Arm_exidx_fixup::update_offset_map(
5432 section_offset_type input_offset,
5433 section_size_type deleted_bytes,
5434 bool delete_entry)
5436 if (this->section_offset_map_ == NULL)
5437 this->section_offset_map_ = new Arm_exidx_section_offset_map();
5438 section_offset_type output_offset;
5439 if (delete_entry)
5440 output_offset = Arm_exidx_input_section::invalid_offset;
5441 else
5442 output_offset = input_offset - deleted_bytes;
5443 (*this->section_offset_map_)[input_offset] = output_offset;
5446 // Process EXIDX_INPUT_SECTION for EXIDX entry merging. Return the number of
5447 // bytes deleted. SECTION_CONTENTS points to the contents of the EXIDX
5448 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5449 // If some entries are merged, also store a pointer to a newly created
5450 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP. The caller
5451 // owns the map and is responsible for releasing it after use.
5453 template<bool big_endian>
5454 uint32_t
5455 Arm_exidx_fixup::process_exidx_section(
5456 const Arm_exidx_input_section* exidx_input_section,
5457 const unsigned char* section_contents,
5458 section_size_type section_size,
5459 Arm_exidx_section_offset_map** psection_offset_map)
5461 Relobj* relobj = exidx_input_section->relobj();
5462 unsigned shndx = exidx_input_section->shndx();
5464 if ((section_size % 8) != 0)
5466 // Something is wrong with this section. Better not touch it.
5467 gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5468 relobj->name().c_str(), shndx);
5469 this->last_input_section_ = exidx_input_section;
5470 this->last_unwind_type_ = UT_NONE;
5471 return 0;
5474 uint32_t deleted_bytes = 0;
5475 bool prev_delete_entry = false;
5476 gold_assert(this->section_offset_map_ == NULL);
5478 for (section_size_type i = 0; i < section_size; i += 8)
5480 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5481 const Valtype* wv =
5482 reinterpret_cast<const Valtype*>(section_contents + i + 4);
5483 uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5485 bool delete_entry = this->process_exidx_entry(second_word);
5487 // Entry deletion causes changes in output offsets. We use a std::map
5488 // to record these. And entry (x, y) means input offset x
5489 // is mapped to output offset y. If y is invalid_offset, then x is
5490 // dropped in the output. Because of the way std::map::lower_bound
5491 // works, we record the last offset in a region w.r.t to keeping or
5492 // dropping. If there is no entry (x0, y0) for an input offset x0,
5493 // the output offset y0 of it is determined by the output offset y1 of
5494 // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5495 // in the map. If y1 is not -1, then y0 = y1 + x0 - x1. Otherwise, y1
5496 // y0 is also -1.
5497 if (delete_entry != prev_delete_entry && i != 0)
5498 this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5500 // Update total deleted bytes for this entry.
5501 if (delete_entry)
5502 deleted_bytes += 8;
5504 prev_delete_entry = delete_entry;
5507 // If section offset map is not NULL, make an entry for the end of
5508 // section.
5509 if (this->section_offset_map_ != NULL)
5510 update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5512 *psection_offset_map = this->section_offset_map_;
5513 this->section_offset_map_ = NULL;
5514 this->last_input_section_ = exidx_input_section;
5516 // Set the first output text section so that we can link the EXIDX output
5517 // section to it. Ignore any EXIDX input section that is completely merged.
5518 if (this->first_output_text_section_ == NULL
5519 && deleted_bytes != section_size)
5521 unsigned int link = exidx_input_section->link();
5522 Output_section* os = relobj->output_section(link);
5523 gold_assert(os != NULL);
5524 this->first_output_text_section_ = os;
5527 return deleted_bytes;
5530 // Arm_output_section methods.
5532 // Create a stub group for input sections from BEGIN to END. OWNER
5533 // points to the input section to be the owner a new stub table.
5535 template<bool big_endian>
5536 void
5537 Arm_output_section<big_endian>::create_stub_group(
5538 Input_section_list::const_iterator begin,
5539 Input_section_list::const_iterator end,
5540 Input_section_list::const_iterator owner,
5541 Target_arm<big_endian>* target,
5542 std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5543 const Task* task)
5545 // We use a different kind of relaxed section in an EXIDX section.
5546 // The static casting from Output_relaxed_input_section to
5547 // Arm_input_section is invalid in an EXIDX section. We are okay
5548 // because we should not be calling this for an EXIDX section.
5549 gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5551 // Currently we convert ordinary input sections into relaxed sections only
5552 // at this point but we may want to support creating relaxed input section
5553 // very early. So we check here to see if owner is already a relaxed
5554 // section.
5556 Arm_input_section<big_endian>* arm_input_section;
5557 if (owner->is_relaxed_input_section())
5559 arm_input_section =
5560 Arm_input_section<big_endian>::as_arm_input_section(
5561 owner->relaxed_input_section());
5563 else
5565 gold_assert(owner->is_input_section());
5566 // Create a new relaxed input section. We need to lock the original
5567 // file.
5568 Task_lock_obj<Object> tl(task, owner->relobj());
5569 arm_input_section =
5570 target->new_arm_input_section(owner->relobj(), owner->shndx());
5571 new_relaxed_sections->push_back(arm_input_section);
5574 // Create a stub table.
5575 Stub_table<big_endian>* stub_table =
5576 target->new_stub_table(arm_input_section);
5578 arm_input_section->set_stub_table(stub_table);
5580 Input_section_list::const_iterator p = begin;
5581 Input_section_list::const_iterator prev_p;
5583 // Look for input sections or relaxed input sections in [begin ... end].
5586 if (p->is_input_section() || p->is_relaxed_input_section())
5588 // The stub table information for input sections live
5589 // in their objects.
5590 Arm_relobj<big_endian>* arm_relobj =
5591 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5592 arm_relobj->set_stub_table(p->shndx(), stub_table);
5594 prev_p = p++;
5596 while (prev_p != end);
5599 // Group input sections for stub generation. GROUP_SIZE is roughly the limit
5600 // of stub groups. We grow a stub group by adding input section until the
5601 // size is just below GROUP_SIZE. The last input section will be converted
5602 // into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5603 // input section after the stub table, effectively double the group size.
5605 // This is similar to the group_sections() function in elf32-arm.c but is
5606 // implemented differently.
5608 template<bool big_endian>
5609 void
5610 Arm_output_section<big_endian>::group_sections(
5611 section_size_type group_size,
5612 bool stubs_always_after_branch,
5613 Target_arm<big_endian>* target,
5614 const Task* task)
5616 // We only care about sections containing code.
5617 if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
5618 return;
5620 // States for grouping.
5621 typedef enum
5623 // No group is being built.
5624 NO_GROUP,
5625 // A group is being built but the stub table is not found yet.
5626 // We keep group a stub group until the size is just under GROUP_SIZE.
5627 // The last input section in the group will be used as the stub table.
5628 FINDING_STUB_SECTION,
5629 // A group is being built and we have already found a stub table.
5630 // We enter this state to grow a stub group by adding input section
5631 // after the stub table. This effectively doubles the group size.
5632 HAS_STUB_SECTION
5633 } State;
5635 // Any newly created relaxed sections are stored here.
5636 std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5638 State state = NO_GROUP;
5639 section_size_type off = 0;
5640 section_size_type group_begin_offset = 0;
5641 section_size_type group_end_offset = 0;
5642 section_size_type stub_table_end_offset = 0;
5643 Input_section_list::const_iterator group_begin =
5644 this->input_sections().end();
5645 Input_section_list::const_iterator stub_table =
5646 this->input_sections().end();
5647 Input_section_list::const_iterator group_end = this->input_sections().end();
5648 for (Input_section_list::const_iterator p = this->input_sections().begin();
5649 p != this->input_sections().end();
5650 ++p)
5652 section_size_type section_begin_offset =
5653 align_address(off, p->addralign());
5654 section_size_type section_end_offset =
5655 section_begin_offset + p->data_size();
5657 // Check to see if we should group the previously seen sections.
5658 switch (state)
5660 case NO_GROUP:
5661 break;
5663 case FINDING_STUB_SECTION:
5664 // Adding this section makes the group larger than GROUP_SIZE.
5665 if (section_end_offset - group_begin_offset >= group_size)
5667 if (stubs_always_after_branch)
5669 gold_assert(group_end != this->input_sections().end());
5670 this->create_stub_group(group_begin, group_end, group_end,
5671 target, &new_relaxed_sections,
5672 task);
5673 state = NO_GROUP;
5675 else
5677 // But wait, there's more! Input sections up to
5678 // stub_group_size bytes after the stub table can be
5679 // handled by it too.
5680 state = HAS_STUB_SECTION;
5681 stub_table = group_end;
5682 stub_table_end_offset = group_end_offset;
5685 break;
5687 case HAS_STUB_SECTION:
5688 // Adding this section makes the post stub-section group larger
5689 // than GROUP_SIZE.
5690 if (section_end_offset - stub_table_end_offset >= group_size)
5692 gold_assert(group_end != this->input_sections().end());
5693 this->create_stub_group(group_begin, group_end, stub_table,
5694 target, &new_relaxed_sections, task);
5695 state = NO_GROUP;
5697 break;
5699 default:
5700 gold_unreachable();
5703 // If we see an input section and currently there is no group, start
5704 // a new one. Skip any empty sections. We look at the data size
5705 // instead of calling p->relobj()->section_size() to avoid locking.
5706 if ((p->is_input_section() || p->is_relaxed_input_section())
5707 && (p->data_size() != 0))
5709 if (state == NO_GROUP)
5711 state = FINDING_STUB_SECTION;
5712 group_begin = p;
5713 group_begin_offset = section_begin_offset;
5716 // Keep track of the last input section seen.
5717 group_end = p;
5718 group_end_offset = section_end_offset;
5721 off = section_end_offset;
5724 // Create a stub group for any ungrouped sections.
5725 if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5727 gold_assert(group_end != this->input_sections().end());
5728 this->create_stub_group(group_begin, group_end,
5729 (state == FINDING_STUB_SECTION
5730 ? group_end
5731 : stub_table),
5732 target, &new_relaxed_sections, task);
5735 // Convert input section into relaxed input section in a batch.
5736 if (!new_relaxed_sections.empty())
5737 this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5739 // Update the section offsets
5740 for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5742 Arm_relobj<big_endian>* arm_relobj =
5743 Arm_relobj<big_endian>::as_arm_relobj(
5744 new_relaxed_sections[i]->relobj());
5745 unsigned int shndx = new_relaxed_sections[i]->shndx();
5746 // Tell Arm_relobj that this input section is converted.
5747 arm_relobj->convert_input_section_to_relaxed_section(shndx);
5751 // Append non empty text sections in this to LIST in ascending
5752 // order of their position in this.
5754 template<bool big_endian>
5755 void
5756 Arm_output_section<big_endian>::append_text_sections_to_list(
5757 Text_section_list* list)
5759 gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5761 for (Input_section_list::const_iterator p = this->input_sections().begin();
5762 p != this->input_sections().end();
5763 ++p)
5765 // We only care about plain or relaxed input sections. We also
5766 // ignore any merged sections.
5767 if (p->is_input_section() || p->is_relaxed_input_section())
5768 list->push_back(Text_section_list::value_type(p->relobj(),
5769 p->shndx()));
5773 template<bool big_endian>
5774 void
5775 Arm_output_section<big_endian>::fix_exidx_coverage(
5776 Layout* layout,
5777 const Text_section_list& sorted_text_sections,
5778 Symbol_table* symtab,
5779 bool merge_exidx_entries,
5780 const Task* task)
5782 // We should only do this for the EXIDX output section.
5783 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5785 // We don't want the relaxation loop to undo these changes, so we discard
5786 // the current saved states and take another one after the fix-up.
5787 this->discard_states();
5789 // Remove all input sections.
5790 uint64_t address = this->address();
5791 typedef std::list<Output_section::Input_section> Input_section_list;
5792 Input_section_list input_sections;
5793 this->reset_address_and_file_offset();
5794 this->get_input_sections(address, std::string(""), &input_sections);
5796 if (!this->input_sections().empty())
5797 gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5799 // Go through all the known input sections and record them.
5800 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5801 typedef Unordered_map<Section_id, const Output_section::Input_section*,
5802 Section_id_hash> Text_to_exidx_map;
5803 Text_to_exidx_map text_to_exidx_map;
5804 for (Input_section_list::const_iterator p = input_sections.begin();
5805 p != input_sections.end();
5806 ++p)
5808 // This should never happen. At this point, we should only see
5809 // plain EXIDX input sections.
5810 gold_assert(!p->is_relaxed_input_section());
5811 text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5814 Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5816 // Go over the sorted text sections.
5817 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5818 Section_id_set processed_input_sections;
5819 for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5820 p != sorted_text_sections.end();
5821 ++p)
5823 Relobj* relobj = p->first;
5824 unsigned int shndx = p->second;
5826 Arm_relobj<big_endian>* arm_relobj =
5827 Arm_relobj<big_endian>::as_arm_relobj(relobj);
5828 const Arm_exidx_input_section* exidx_input_section =
5829 arm_relobj->exidx_input_section_by_link(shndx);
5831 // If this text section has no EXIDX section or if the EXIDX section
5832 // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5833 // of the last seen EXIDX section.
5834 if (exidx_input_section == NULL || exidx_input_section->has_errors())
5836 exidx_fixup.add_exidx_cantunwind_as_needed();
5837 continue;
5840 Relobj* exidx_relobj = exidx_input_section->relobj();
5841 unsigned int exidx_shndx = exidx_input_section->shndx();
5842 Section_id sid(exidx_relobj, exidx_shndx);
5843 Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5844 if (iter == text_to_exidx_map.end())
5846 // This is odd. We have not seen this EXIDX input section before.
5847 // We cannot do fix-up. If we saw a SECTIONS clause in a script,
5848 // issue a warning instead. We assume the user knows what he
5849 // or she is doing. Otherwise, this is an error.
5850 if (layout->script_options()->saw_sections_clause())
5851 gold_warning(_("unwinding may not work because EXIDX input section"
5852 " %u of %s is not in EXIDX output section"),
5853 exidx_shndx, exidx_relobj->name().c_str());
5854 else
5855 gold_error(_("unwinding may not work because EXIDX input section"
5856 " %u of %s is not in EXIDX output section"),
5857 exidx_shndx, exidx_relobj->name().c_str());
5859 exidx_fixup.add_exidx_cantunwind_as_needed();
5860 continue;
5863 // We need to access the contents of the EXIDX section, lock the
5864 // object here.
5865 Task_lock_obj<Object> tl(task, exidx_relobj);
5866 section_size_type exidx_size;
5867 const unsigned char* exidx_contents =
5868 exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5870 // Fix up coverage and append input section to output data list.
5871 Arm_exidx_section_offset_map* section_offset_map = NULL;
5872 uint32_t deleted_bytes =
5873 exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5874 exidx_contents,
5875 exidx_size,
5876 &section_offset_map);
5878 if (deleted_bytes == exidx_input_section->size())
5880 // The whole EXIDX section got merged. Remove it from output.
5881 gold_assert(section_offset_map == NULL);
5882 exidx_relobj->set_output_section(exidx_shndx, NULL);
5884 // All local symbols defined in this input section will be dropped.
5885 // We need to adjust output local symbol count.
5886 arm_relobj->set_output_local_symbol_count_needs_update();
5888 else if (deleted_bytes > 0)
5890 // Some entries are merged. We need to convert this EXIDX input
5891 // section into a relaxed section.
5892 gold_assert(section_offset_map != NULL);
5894 Arm_exidx_merged_section* merged_section =
5895 new Arm_exidx_merged_section(*exidx_input_section,
5896 *section_offset_map, deleted_bytes);
5897 merged_section->build_contents(exidx_contents, exidx_size);
5899 const std::string secname = exidx_relobj->section_name(exidx_shndx);
5900 this->add_relaxed_input_section(layout, merged_section, secname);
5901 arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5903 // All local symbols defined in discarded portions of this input
5904 // section will be dropped. We need to adjust output local symbol
5905 // count.
5906 arm_relobj->set_output_local_symbol_count_needs_update();
5908 else
5910 // Just add back the EXIDX input section.
5911 gold_assert(section_offset_map == NULL);
5912 const Output_section::Input_section* pis = iter->second;
5913 gold_assert(pis->is_input_section());
5914 this->add_script_input_section(*pis);
5917 processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5920 // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5921 exidx_fixup.add_exidx_cantunwind_as_needed();
5923 // Remove any known EXIDX input sections that are not processed.
5924 for (Input_section_list::const_iterator p = input_sections.begin();
5925 p != input_sections.end();
5926 ++p)
5928 if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5929 == processed_input_sections.end())
5931 // We discard a known EXIDX section because its linked
5932 // text section has been folded by ICF. We also discard an
5933 // EXIDX section with error, the output does not matter in this
5934 // case. We do this to avoid triggering asserts.
5935 Arm_relobj<big_endian>* arm_relobj =
5936 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5937 const Arm_exidx_input_section* exidx_input_section =
5938 arm_relobj->exidx_input_section_by_shndx(p->shndx());
5939 gold_assert(exidx_input_section != NULL);
5940 if (!exidx_input_section->has_errors())
5942 unsigned int text_shndx = exidx_input_section->link();
5943 gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5946 // Remove this from link. We also need to recount the
5947 // local symbols.
5948 p->relobj()->set_output_section(p->shndx(), NULL);
5949 arm_relobj->set_output_local_symbol_count_needs_update();
5953 // Link exidx output section to the first seen output section and
5954 // set correct entry size.
5955 this->set_link_section(exidx_fixup.first_output_text_section());
5956 this->set_entsize(8);
5958 // Make changes permanent.
5959 this->save_states();
5960 this->set_section_offsets_need_adjustment();
5963 // Link EXIDX output sections to text output sections.
5965 template<bool big_endian>
5966 void
5967 Arm_output_section<big_endian>::set_exidx_section_link()
5969 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5970 if (!this->input_sections().empty())
5972 Input_section_list::const_iterator p = this->input_sections().begin();
5973 Arm_relobj<big_endian>* arm_relobj =
5974 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5975 unsigned exidx_shndx = p->shndx();
5976 const Arm_exidx_input_section* exidx_input_section =
5977 arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
5978 gold_assert(exidx_input_section != NULL);
5979 unsigned int text_shndx = exidx_input_section->link();
5980 Output_section* os = arm_relobj->output_section(text_shndx);
5981 this->set_link_section(os);
5985 // Arm_relobj methods.
5987 // Determine if an input section is scannable for stub processing. SHDR is
5988 // the header of the section and SHNDX is the section index. OS is the output
5989 // section for the input section and SYMTAB is the global symbol table used to
5990 // look up ICF information.
5992 template<bool big_endian>
5993 bool
5994 Arm_relobj<big_endian>::section_is_scannable(
5995 const elfcpp::Shdr<32, big_endian>& shdr,
5996 unsigned int shndx,
5997 const Output_section* os,
5998 const Symbol_table* symtab)
6000 // Skip any empty sections, unallocated sections or sections whose
6001 // type are not SHT_PROGBITS.
6002 if (shdr.get_sh_size() == 0
6003 || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6004 || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6005 return false;
6007 // Skip any discarded or ICF'ed sections.
6008 if (os == NULL || symtab->is_section_folded(this, shndx))
6009 return false;
6011 // If this requires special offset handling, check to see if it is
6012 // a relaxed section. If this is not, then it is a merged section that
6013 // we cannot handle.
6014 if (this->is_output_section_offset_invalid(shndx))
6016 const Output_relaxed_input_section* poris =
6017 os->find_relaxed_input_section(this, shndx);
6018 if (poris == NULL)
6019 return false;
6022 return true;
6025 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6026 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6028 template<bool big_endian>
6029 bool
6030 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6031 const elfcpp::Shdr<32, big_endian>& shdr,
6032 const Relobj::Output_sections& out_sections,
6033 const Symbol_table* symtab,
6034 const unsigned char* pshdrs)
6036 unsigned int sh_type = shdr.get_sh_type();
6037 if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6038 return false;
6040 // Ignore empty section.
6041 off_t sh_size = shdr.get_sh_size();
6042 if (sh_size == 0)
6043 return false;
6045 // Ignore reloc section with unexpected symbol table. The
6046 // error will be reported in the final link.
6047 if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6048 return false;
6050 unsigned int reloc_size;
6051 if (sh_type == elfcpp::SHT_REL)
6052 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6053 else
6054 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6056 // Ignore reloc section with unexpected entsize or uneven size.
6057 // The error will be reported in the final link.
6058 if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6059 return false;
6061 // Ignore reloc section with bad info. This error will be
6062 // reported in the final link.
6063 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6064 if (index >= this->shnum())
6065 return false;
6067 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6068 const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6069 return this->section_is_scannable(text_shdr, index,
6070 out_sections[index], symtab);
6073 // Return the output address of either a plain input section or a relaxed
6074 // input section. SHNDX is the section index. We define and use this
6075 // instead of calling Output_section::output_address because that is slow
6076 // for large output.
6078 template<bool big_endian>
6079 Arm_address
6080 Arm_relobj<big_endian>::simple_input_section_output_address(
6081 unsigned int shndx,
6082 Output_section* os)
6084 if (this->is_output_section_offset_invalid(shndx))
6086 const Output_relaxed_input_section* poris =
6087 os->find_relaxed_input_section(this, shndx);
6088 // We do not handle merged sections here.
6089 gold_assert(poris != NULL);
6090 return poris->address();
6092 else
6093 return os->address() + this->get_output_section_offset(shndx);
6096 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6097 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6099 template<bool big_endian>
6100 bool
6101 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6102 const elfcpp::Shdr<32, big_endian>& shdr,
6103 unsigned int shndx,
6104 Output_section* os,
6105 const Symbol_table* symtab)
6107 if (!this->section_is_scannable(shdr, shndx, os, symtab))
6108 return false;
6110 // If the section does not cross any 4K-boundaries, it does not need to
6111 // be scanned.
6112 Arm_address address = this->simple_input_section_output_address(shndx, os);
6113 if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6114 return false;
6116 return true;
6119 // Scan a section for Cortex-A8 workaround.
6121 template<bool big_endian>
6122 void
6123 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6124 const elfcpp::Shdr<32, big_endian>& shdr,
6125 unsigned int shndx,
6126 Output_section* os,
6127 Target_arm<big_endian>* arm_target)
6129 // Look for the first mapping symbol in this section. It should be
6130 // at (shndx, 0).
6131 Mapping_symbol_position section_start(shndx, 0);
6132 typename Mapping_symbols_info::const_iterator p =
6133 this->mapping_symbols_info_.lower_bound(section_start);
6135 // There are no mapping symbols for this section. Treat it as a data-only
6136 // section. Issue a warning if section is marked as containing
6137 // instructions.
6138 if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6140 if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6141 gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6142 "erratum because it has no mapping symbols."),
6143 shndx, this->name().c_str());
6144 return;
6147 Arm_address output_address =
6148 this->simple_input_section_output_address(shndx, os);
6150 // Get the section contents.
6151 section_size_type input_view_size = 0;
6152 const unsigned char* input_view =
6153 this->section_contents(shndx, &input_view_size, false);
6155 // We need to go through the mapping symbols to determine what to
6156 // scan. There are two reasons. First, we should look at THUMB code and
6157 // THUMB code only. Second, we only want to look at the 4K-page boundary
6158 // to speed up the scanning.
6160 while (p != this->mapping_symbols_info_.end()
6161 && p->first.first == shndx)
6163 typename Mapping_symbols_info::const_iterator next =
6164 this->mapping_symbols_info_.upper_bound(p->first);
6166 // Only scan part of a section with THUMB code.
6167 if (p->second == 't')
6169 // Determine the end of this range.
6170 section_size_type span_start =
6171 convert_to_section_size_type(p->first.second);
6172 section_size_type span_end;
6173 if (next != this->mapping_symbols_info_.end()
6174 && next->first.first == shndx)
6175 span_end = convert_to_section_size_type(next->first.second);
6176 else
6177 span_end = convert_to_section_size_type(shdr.get_sh_size());
6179 if (((span_start + output_address) & ~0xfffUL)
6180 != ((span_end + output_address - 1) & ~0xfffUL))
6182 arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6183 span_start, span_end,
6184 input_view,
6185 output_address);
6189 p = next;
6193 // Scan relocations for stub generation.
6195 template<bool big_endian>
6196 void
6197 Arm_relobj<big_endian>::scan_sections_for_stubs(
6198 Target_arm<big_endian>* arm_target,
6199 const Symbol_table* symtab,
6200 const Layout* layout)
6202 unsigned int shnum = this->shnum();
6203 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6205 // Read the section headers.
6206 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6207 shnum * shdr_size,
6208 true, true);
6210 // To speed up processing, we set up hash tables for fast lookup of
6211 // input offsets to output addresses.
6212 this->initialize_input_to_output_maps();
6214 const Relobj::Output_sections& out_sections(this->output_sections());
6216 Relocate_info<32, big_endian> relinfo;
6217 relinfo.symtab = symtab;
6218 relinfo.layout = layout;
6219 relinfo.object = this;
6221 // Do relocation stubs scanning.
6222 const unsigned char* p = pshdrs + shdr_size;
6223 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6225 const elfcpp::Shdr<32, big_endian> shdr(p);
6226 if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6227 pshdrs))
6229 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6230 Arm_address output_offset = this->get_output_section_offset(index);
6231 Arm_address output_address;
6232 if (output_offset != invalid_address)
6233 output_address = out_sections[index]->address() + output_offset;
6234 else
6236 // Currently this only happens for a relaxed section.
6237 const Output_relaxed_input_section* poris =
6238 out_sections[index]->find_relaxed_input_section(this, index);
6239 gold_assert(poris != NULL);
6240 output_address = poris->address();
6243 // Get the relocations.
6244 const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6245 shdr.get_sh_size(),
6246 true, false);
6248 // Get the section contents. This does work for the case in which
6249 // we modify the contents of an input section. We need to pass the
6250 // output view under such circumstances.
6251 section_size_type input_view_size = 0;
6252 const unsigned char* input_view =
6253 this->section_contents(index, &input_view_size, false);
6255 relinfo.reloc_shndx = i;
6256 relinfo.data_shndx = index;
6257 unsigned int sh_type = shdr.get_sh_type();
6258 unsigned int reloc_size;
6259 if (sh_type == elfcpp::SHT_REL)
6260 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6261 else
6262 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6264 Output_section* os = out_sections[index];
6265 arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6266 shdr.get_sh_size() / reloc_size,
6268 output_offset == invalid_address,
6269 input_view, output_address,
6270 input_view_size);
6274 // Do Cortex-A8 erratum stubs scanning. This has to be done for a section
6275 // after its relocation section, if there is one, is processed for
6276 // relocation stubs. Merging this loop with the one above would have been
6277 // complicated since we would have had to make sure that relocation stub
6278 // scanning is done first.
6279 if (arm_target->fix_cortex_a8())
6281 const unsigned char* p = pshdrs + shdr_size;
6282 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6284 const elfcpp::Shdr<32, big_endian> shdr(p);
6285 if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6286 out_sections[i],
6287 symtab))
6288 this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6289 arm_target);
6293 // After we've done the relocations, we release the hash tables,
6294 // since we no longer need them.
6295 this->free_input_to_output_maps();
6298 // Count the local symbols. The ARM backend needs to know if a symbol
6299 // is a THUMB function or not. For global symbols, it is easy because
6300 // the Symbol object keeps the ELF symbol type. For local symbol it is
6301 // harder because we cannot access this information. So we override the
6302 // do_count_local_symbol in parent and scan local symbols to mark
6303 // THUMB functions. This is not the most efficient way but I do not want to
6304 // slow down other ports by calling a per symbol target hook inside
6305 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6307 template<bool big_endian>
6308 void
6309 Arm_relobj<big_endian>::do_count_local_symbols(
6310 Stringpool_template<char>* pool,
6311 Stringpool_template<char>* dynpool)
6313 // We need to fix-up the values of any local symbols whose type are
6314 // STT_ARM_TFUNC.
6316 // Ask parent to count the local symbols.
6317 Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6318 const unsigned int loccount = this->local_symbol_count();
6319 if (loccount == 0)
6320 return;
6322 // Initialize the thumb function bit-vector.
6323 std::vector<bool> empty_vector(loccount, false);
6324 this->local_symbol_is_thumb_function_.swap(empty_vector);
6326 // Read the symbol table section header.
6327 const unsigned int symtab_shndx = this->symtab_shndx();
6328 elfcpp::Shdr<32, big_endian>
6329 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6330 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6332 // Read the local symbols.
6333 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6334 gold_assert(loccount == symtabshdr.get_sh_info());
6335 off_t locsize = loccount * sym_size;
6336 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6337 locsize, true, true);
6339 // For mapping symbol processing, we need to read the symbol names.
6340 unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6341 if (strtab_shndx >= this->shnum())
6343 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6344 return;
6347 elfcpp::Shdr<32, big_endian>
6348 strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6349 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6351 this->error(_("symbol table name section has wrong type: %u"),
6352 static_cast<unsigned int>(strtabshdr.get_sh_type()));
6353 return;
6355 const char* pnames =
6356 reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6357 strtabshdr.get_sh_size(),
6358 false, false));
6360 // Loop over the local symbols and mark any local symbols pointing
6361 // to THUMB functions.
6363 // Skip the first dummy symbol.
6364 psyms += sym_size;
6365 typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6366 this->local_values();
6367 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6369 elfcpp::Sym<32, big_endian> sym(psyms);
6370 elfcpp::STT st_type = sym.get_st_type();
6371 Symbol_value<32>& lv((*plocal_values)[i]);
6372 Arm_address input_value = lv.input_value();
6374 // Check to see if this is a mapping symbol.
6375 const char* sym_name = pnames + sym.get_st_name();
6376 if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6378 bool is_ordinary;
6379 unsigned int input_shndx =
6380 this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6381 gold_assert(is_ordinary);
6383 // Strip of LSB in case this is a THUMB symbol.
6384 Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6385 this->mapping_symbols_info_[msp] = sym_name[1];
6388 if (st_type == elfcpp::STT_ARM_TFUNC
6389 || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6391 // This is a THUMB function. Mark this and canonicalize the
6392 // symbol value by setting LSB.
6393 this->local_symbol_is_thumb_function_[i] = true;
6394 if ((input_value & 1) == 0)
6395 lv.set_input_value(input_value | 1);
6400 // Relocate sections.
6401 template<bool big_endian>
6402 void
6403 Arm_relobj<big_endian>::do_relocate_sections(
6404 const Symbol_table* symtab,
6405 const Layout* layout,
6406 const unsigned char* pshdrs,
6407 Output_file* of,
6408 typename Sized_relobj_file<32, big_endian>::Views* pviews)
6410 // Call parent to relocate sections.
6411 Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6412 pshdrs, of, pviews);
6414 // We do not generate stubs if doing a relocatable link.
6415 if (parameters->options().relocatable())
6416 return;
6418 // Relocate stub tables.
6419 unsigned int shnum = this->shnum();
6421 Target_arm<big_endian>* arm_target =
6422 Target_arm<big_endian>::default_target();
6424 Relocate_info<32, big_endian> relinfo;
6425 relinfo.symtab = symtab;
6426 relinfo.layout = layout;
6427 relinfo.object = this;
6429 for (unsigned int i = 1; i < shnum; ++i)
6431 Arm_input_section<big_endian>* arm_input_section =
6432 arm_target->find_arm_input_section(this, i);
6434 if (arm_input_section != NULL
6435 && arm_input_section->is_stub_table_owner()
6436 && !arm_input_section->stub_table()->empty())
6438 // We cannot discard a section if it owns a stub table.
6439 Output_section* os = this->output_section(i);
6440 gold_assert(os != NULL);
6442 relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6443 relinfo.reloc_shdr = NULL;
6444 relinfo.data_shndx = i;
6445 relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6447 gold_assert((*pviews)[i].view != NULL);
6449 // We are passed the output section view. Adjust it to cover the
6450 // stub table only.
6451 Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6452 gold_assert((stub_table->address() >= (*pviews)[i].address)
6453 && ((stub_table->address() + stub_table->data_size())
6454 <= (*pviews)[i].address + (*pviews)[i].view_size));
6456 off_t offset = stub_table->address() - (*pviews)[i].address;
6457 unsigned char* view = (*pviews)[i].view + offset;
6458 Arm_address address = stub_table->address();
6459 section_size_type view_size = stub_table->data_size();
6461 stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6462 view_size);
6465 // Apply Cortex A8 workaround if applicable.
6466 if (this->section_has_cortex_a8_workaround(i))
6468 unsigned char* view = (*pviews)[i].view;
6469 Arm_address view_address = (*pviews)[i].address;
6470 section_size_type view_size = (*pviews)[i].view_size;
6471 Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6473 // Adjust view to cover section.
6474 Output_section* os = this->output_section(i);
6475 gold_assert(os != NULL);
6476 Arm_address section_address =
6477 this->simple_input_section_output_address(i, os);
6478 uint64_t section_size = this->section_size(i);
6480 gold_assert(section_address >= view_address
6481 && ((section_address + section_size)
6482 <= (view_address + view_size)));
6484 unsigned char* section_view = view + (section_address - view_address);
6486 // Apply the Cortex-A8 workaround to the output address range
6487 // corresponding to this input section.
6488 stub_table->apply_cortex_a8_workaround_to_address_range(
6489 arm_target,
6490 section_view,
6491 section_address,
6492 section_size);
6497 // Find the linked text section of an EXIDX section by looking at the first
6498 // relocation. 4.4.1 of the EHABI specifications says that an EXIDX section
6499 // must be linked to its associated code section via the sh_link field of
6500 // its section header. However, some tools are broken and the link is not
6501 // always set. LD just drops such an EXIDX section silently, causing the
6502 // associated code not unwindabled. Here we try a little bit harder to
6503 // discover the linked code section.
6505 // PSHDR points to the section header of a relocation section of an EXIDX
6506 // section. If we can find a linked text section, return true and
6507 // store the text section index in the location PSHNDX. Otherwise
6508 // return false.
6510 template<bool big_endian>
6511 bool
6512 Arm_relobj<big_endian>::find_linked_text_section(
6513 const unsigned char* pshdr,
6514 const unsigned char* psyms,
6515 unsigned int* pshndx)
6517 elfcpp::Shdr<32, big_endian> shdr(pshdr);
6519 // If there is no relocation, we cannot find the linked text section.
6520 size_t reloc_size;
6521 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6522 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6523 else
6524 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6525 size_t reloc_count = shdr.get_sh_size() / reloc_size;
6527 // Get the relocations.
6528 const unsigned char* prelocs =
6529 this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6531 // Find the REL31 relocation for the first word of the first EXIDX entry.
6532 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6534 Arm_address r_offset;
6535 typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6536 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6538 typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6539 r_info = reloc.get_r_info();
6540 r_offset = reloc.get_r_offset();
6542 else
6544 typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6545 r_info = reloc.get_r_info();
6546 r_offset = reloc.get_r_offset();
6549 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6550 if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6551 continue;
6553 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6554 if (r_sym == 0
6555 || r_sym >= this->local_symbol_count()
6556 || r_offset != 0)
6557 continue;
6559 // This is the relocation for the first word of the first EXIDX entry.
6560 // We expect to see a local section symbol.
6561 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6562 elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6563 if (sym.get_st_type() == elfcpp::STT_SECTION)
6565 bool is_ordinary;
6566 *pshndx =
6567 this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6568 gold_assert(is_ordinary);
6569 return true;
6571 else
6572 return false;
6575 return false;
6578 // Make an EXIDX input section object for an EXIDX section whose index is
6579 // SHNDX. SHDR is the section header of the EXIDX section and TEXT_SHNDX
6580 // is the section index of the linked text section.
6582 template<bool big_endian>
6583 void
6584 Arm_relobj<big_endian>::make_exidx_input_section(
6585 unsigned int shndx,
6586 const elfcpp::Shdr<32, big_endian>& shdr,
6587 unsigned int text_shndx,
6588 const elfcpp::Shdr<32, big_endian>& text_shdr)
6590 // Create an Arm_exidx_input_section object for this EXIDX section.
6591 Arm_exidx_input_section* exidx_input_section =
6592 new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6593 shdr.get_sh_addralign(),
6594 text_shdr.get_sh_size());
6596 gold_assert(this->exidx_section_map_[shndx] == NULL);
6597 this->exidx_section_map_[shndx] = exidx_input_section;
6599 if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6601 gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6602 this->section_name(shndx).c_str(), shndx, text_shndx,
6603 this->name().c_str());
6604 exidx_input_section->set_has_errors();
6606 else if (this->exidx_section_map_[text_shndx] != NULL)
6608 unsigned other_exidx_shndx =
6609 this->exidx_section_map_[text_shndx]->shndx();
6610 gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6611 "%s(%u) in %s"),
6612 this->section_name(shndx).c_str(), shndx,
6613 this->section_name(other_exidx_shndx).c_str(),
6614 other_exidx_shndx, this->section_name(text_shndx).c_str(),
6615 text_shndx, this->name().c_str());
6616 exidx_input_section->set_has_errors();
6618 else
6619 this->exidx_section_map_[text_shndx] = exidx_input_section;
6621 // Check section flags of text section.
6622 if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6624 gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6625 " in %s"),
6626 this->section_name(shndx).c_str(), shndx,
6627 this->section_name(text_shndx).c_str(), text_shndx,
6628 this->name().c_str());
6629 exidx_input_section->set_has_errors();
6631 else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6632 // I would like to make this an error but currently ld just ignores
6633 // this.
6634 gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6635 "%s(%u) in %s"),
6636 this->section_name(shndx).c_str(), shndx,
6637 this->section_name(text_shndx).c_str(), text_shndx,
6638 this->name().c_str());
6641 // Read the symbol information.
6643 template<bool big_endian>
6644 void
6645 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6647 // Call parent class to read symbol information.
6648 Sized_relobj_file<32, big_endian>::do_read_symbols(sd);
6650 // If this input file is a binary file, it has no processor
6651 // specific flags and attributes section.
6652 Input_file::Format format = this->input_file()->format();
6653 if (format != Input_file::FORMAT_ELF)
6655 gold_assert(format == Input_file::FORMAT_BINARY);
6656 this->merge_flags_and_attributes_ = false;
6657 return;
6660 // Read processor-specific flags in ELF file header.
6661 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6662 elfcpp::Elf_sizes<32>::ehdr_size,
6663 true, false);
6664 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6665 this->processor_specific_flags_ = ehdr.get_e_flags();
6667 // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6668 // sections.
6669 std::vector<unsigned int> deferred_exidx_sections;
6670 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6671 const unsigned char* pshdrs = sd->section_headers->data();
6672 const unsigned char* ps = pshdrs + shdr_size;
6673 bool must_merge_flags_and_attributes = false;
6674 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6676 elfcpp::Shdr<32, big_endian> shdr(ps);
6678 // Sometimes an object has no contents except the section name string
6679 // table and an empty symbol table with the undefined symbol. We
6680 // don't want to merge processor-specific flags from such an object.
6681 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6683 // Symbol table is not empty.
6684 const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6685 elfcpp::Elf_sizes<32>::sym_size;
6686 if (shdr.get_sh_size() > sym_size)
6687 must_merge_flags_and_attributes = true;
6689 else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6690 // If this is neither an empty symbol table nor a string table,
6691 // be conservative.
6692 must_merge_flags_and_attributes = true;
6694 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6696 gold_assert(this->attributes_section_data_ == NULL);
6697 section_offset_type section_offset = shdr.get_sh_offset();
6698 section_size_type section_size =
6699 convert_to_section_size_type(shdr.get_sh_size());
6700 const unsigned char* view =
6701 this->get_view(section_offset, section_size, true, false);
6702 this->attributes_section_data_ =
6703 new Attributes_section_data(view, section_size);
6705 else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6707 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6708 if (text_shndx == elfcpp::SHN_UNDEF)
6709 deferred_exidx_sections.push_back(i);
6710 else
6712 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6713 + text_shndx * shdr_size);
6714 this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6716 // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6717 if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6718 gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6719 this->section_name(i).c_str(), this->name().c_str());
6723 // This is rare.
6724 if (!must_merge_flags_and_attributes)
6726 gold_assert(deferred_exidx_sections.empty());
6727 this->merge_flags_and_attributes_ = false;
6728 return;
6731 // Some tools are broken and they do not set the link of EXIDX sections.
6732 // We look at the first relocation to figure out the linked sections.
6733 if (!deferred_exidx_sections.empty())
6735 // We need to go over the section headers again to find the mapping
6736 // from sections being relocated to their relocation sections. This is
6737 // a bit inefficient as we could do that in the loop above. However,
6738 // we do not expect any deferred EXIDX sections normally. So we do not
6739 // want to slow down the most common path.
6740 typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6741 Reloc_map reloc_map;
6742 ps = pshdrs + shdr_size;
6743 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6745 elfcpp::Shdr<32, big_endian> shdr(ps);
6746 elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6747 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6749 unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6750 if (info_shndx >= this->shnum())
6751 gold_error(_("relocation section %u has invalid info %u"),
6752 i, info_shndx);
6753 Reloc_map::value_type value(info_shndx, i);
6754 std::pair<Reloc_map::iterator, bool> result =
6755 reloc_map.insert(value);
6756 if (!result.second)
6757 gold_error(_("section %u has multiple relocation sections "
6758 "%u and %u"),
6759 info_shndx, i, reloc_map[info_shndx]);
6763 // Read the symbol table section header.
6764 const unsigned int symtab_shndx = this->symtab_shndx();
6765 elfcpp::Shdr<32, big_endian>
6766 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6767 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6769 // Read the local symbols.
6770 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6771 const unsigned int loccount = this->local_symbol_count();
6772 gold_assert(loccount == symtabshdr.get_sh_info());
6773 off_t locsize = loccount * sym_size;
6774 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6775 locsize, true, true);
6777 // Process the deferred EXIDX sections.
6778 for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6780 unsigned int shndx = deferred_exidx_sections[i];
6781 elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6782 unsigned int text_shndx = elfcpp::SHN_UNDEF;
6783 Reloc_map::const_iterator it = reloc_map.find(shndx);
6784 if (it != reloc_map.end())
6785 find_linked_text_section(pshdrs + it->second * shdr_size,
6786 psyms, &text_shndx);
6787 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6788 + text_shndx * shdr_size);
6789 this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6794 // Process relocations for garbage collection. The ARM target uses .ARM.exidx
6795 // sections for unwinding. These sections are referenced implicitly by
6796 // text sections linked in the section headers. If we ignore these implicit
6797 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6798 // will be garbage-collected incorrectly. Hence we override the same function
6799 // in the base class to handle these implicit references.
6801 template<bool big_endian>
6802 void
6803 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6804 Layout* layout,
6805 Read_relocs_data* rd)
6807 // First, call base class method to process relocations in this object.
6808 Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6810 // If --gc-sections is not specified, there is nothing more to do.
6811 // This happens when --icf is used but --gc-sections is not.
6812 if (!parameters->options().gc_sections())
6813 return;
6815 unsigned int shnum = this->shnum();
6816 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6817 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6818 shnum * shdr_size,
6819 true, true);
6821 // Scan section headers for sections of type SHT_ARM_EXIDX. Add references
6822 // to these from the linked text sections.
6823 const unsigned char* ps = pshdrs + shdr_size;
6824 for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6826 elfcpp::Shdr<32, big_endian> shdr(ps);
6827 if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6829 // Found an .ARM.exidx section, add it to the set of reachable
6830 // sections from its linked text section.
6831 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6832 symtab->gc()->add_reference(this, text_shndx, this, i);
6837 // Update output local symbol count. Owing to EXIDX entry merging, some local
6838 // symbols will be removed in output. Adjust output local symbol count
6839 // accordingly. We can only changed the static output local symbol count. It
6840 // is too late to change the dynamic symbols.
6842 template<bool big_endian>
6843 void
6844 Arm_relobj<big_endian>::update_output_local_symbol_count()
6846 // Caller should check that this needs updating. We want caller checking
6847 // because output_local_symbol_count_needs_update() is most likely inlined.
6848 gold_assert(this->output_local_symbol_count_needs_update_);
6850 gold_assert(this->symtab_shndx() != -1U);
6851 if (this->symtab_shndx() == 0)
6853 // This object has no symbols. Weird but legal.
6854 return;
6857 // Read the symbol table section header.
6858 const unsigned int symtab_shndx = this->symtab_shndx();
6859 elfcpp::Shdr<32, big_endian>
6860 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6861 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6863 // Read the local symbols.
6864 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6865 const unsigned int loccount = this->local_symbol_count();
6866 gold_assert(loccount == symtabshdr.get_sh_info());
6867 off_t locsize = loccount * sym_size;
6868 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6869 locsize, true, true);
6871 // Loop over the local symbols.
6873 typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6874 Output_sections;
6875 const Output_sections& out_sections(this->output_sections());
6876 unsigned int shnum = this->shnum();
6877 unsigned int count = 0;
6878 // Skip the first, dummy, symbol.
6879 psyms += sym_size;
6880 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6882 elfcpp::Sym<32, big_endian> sym(psyms);
6884 Symbol_value<32>& lv((*this->local_values())[i]);
6886 // This local symbol was already discarded by do_count_local_symbols.
6887 if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6888 continue;
6890 bool is_ordinary;
6891 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6892 &is_ordinary);
6894 if (shndx < shnum)
6896 Output_section* os = out_sections[shndx];
6898 // This local symbol no longer has an output section. Discard it.
6899 if (os == NULL)
6901 lv.set_no_output_symtab_entry();
6902 continue;
6905 // Currently we only discard parts of EXIDX input sections.
6906 // We explicitly check for a merged EXIDX input section to avoid
6907 // calling Output_section_data::output_offset unless necessary.
6908 if ((this->get_output_section_offset(shndx) == invalid_address)
6909 && (this->exidx_input_section_by_shndx(shndx) != NULL))
6911 section_offset_type output_offset =
6912 os->output_offset(this, shndx, lv.input_value());
6913 if (output_offset == -1)
6915 // This symbol is defined in a part of an EXIDX input section
6916 // that is discarded due to entry merging.
6917 lv.set_no_output_symtab_entry();
6918 continue;
6923 ++count;
6926 this->set_output_local_symbol_count(count);
6927 this->output_local_symbol_count_needs_update_ = false;
6930 // Arm_dynobj methods.
6932 // Read the symbol information.
6934 template<bool big_endian>
6935 void
6936 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6938 // Call parent class to read symbol information.
6939 Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6941 // Read processor-specific flags in ELF file header.
6942 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6943 elfcpp::Elf_sizes<32>::ehdr_size,
6944 true, false);
6945 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6946 this->processor_specific_flags_ = ehdr.get_e_flags();
6948 // Read the attributes section if there is one.
6949 // We read from the end because gas seems to put it near the end of
6950 // the section headers.
6951 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6952 const unsigned char* ps =
6953 sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6954 for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6956 elfcpp::Shdr<32, big_endian> shdr(ps);
6957 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6959 section_offset_type section_offset = shdr.get_sh_offset();
6960 section_size_type section_size =
6961 convert_to_section_size_type(shdr.get_sh_size());
6962 const unsigned char* view =
6963 this->get_view(section_offset, section_size, true, false);
6964 this->attributes_section_data_ =
6965 new Attributes_section_data(view, section_size);
6966 break;
6971 // Stub_addend_reader methods.
6973 // Read the addend of a REL relocation of type R_TYPE at VIEW.
6975 template<bool big_endian>
6976 elfcpp::Elf_types<32>::Elf_Swxword
6977 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
6978 unsigned int r_type,
6979 const unsigned char* view,
6980 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
6982 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
6984 switch (r_type)
6986 case elfcpp::R_ARM_CALL:
6987 case elfcpp::R_ARM_JUMP24:
6988 case elfcpp::R_ARM_PLT32:
6990 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
6991 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6992 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
6993 return Bits<26>::sign_extend32(val << 2);
6996 case elfcpp::R_ARM_THM_CALL:
6997 case elfcpp::R_ARM_THM_JUMP24:
6998 case elfcpp::R_ARM_THM_XPC22:
7000 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7001 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7002 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7003 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7004 return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7007 case elfcpp::R_ARM_THM_JUMP19:
7009 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7010 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7011 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7012 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7013 return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7016 default:
7017 gold_unreachable();
7021 // Arm_output_data_got methods.
7023 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
7024 // The first one is initialized to be 1, which is the module index for
7025 // the main executable and the second one 0. A reloc of the type
7026 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7027 // be applied by gold. GSYM is a global symbol.
7029 template<bool big_endian>
7030 void
7031 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7032 unsigned int got_type,
7033 Symbol* gsym)
7035 if (gsym->has_got_offset(got_type))
7036 return;
7038 // We are doing a static link. Just mark it as belong to module 1,
7039 // the executable.
7040 unsigned int got_offset = this->add_constant(1);
7041 gsym->set_got_offset(got_type, got_offset);
7042 got_offset = this->add_constant(0);
7043 this->static_relocs_.push_back(Static_reloc(got_offset,
7044 elfcpp::R_ARM_TLS_DTPOFF32,
7045 gsym));
7048 // Same as the above but for a local symbol.
7050 template<bool big_endian>
7051 void
7052 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7053 unsigned int got_type,
7054 Sized_relobj_file<32, big_endian>* object,
7055 unsigned int index)
7057 if (object->local_has_got_offset(index, got_type))
7058 return;
7060 // We are doing a static link. Just mark it as belong to module 1,
7061 // the executable.
7062 unsigned int got_offset = this->add_constant(1);
7063 object->set_local_got_offset(index, got_type, got_offset);
7064 got_offset = this->add_constant(0);
7065 this->static_relocs_.push_back(Static_reloc(got_offset,
7066 elfcpp::R_ARM_TLS_DTPOFF32,
7067 object, index));
7070 template<bool big_endian>
7071 void
7072 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7074 // Call parent to write out GOT.
7075 Output_data_got<32, big_endian>::do_write(of);
7077 // We are done if there is no fix up.
7078 if (this->static_relocs_.empty())
7079 return;
7081 gold_assert(parameters->doing_static_link());
7083 const off_t offset = this->offset();
7084 const section_size_type oview_size =
7085 convert_to_section_size_type(this->data_size());
7086 unsigned char* const oview = of->get_output_view(offset, oview_size);
7088 Output_segment* tls_segment = this->layout_->tls_segment();
7089 gold_assert(tls_segment != NULL);
7091 // The thread pointer $tp points to the TCB, which is followed by the
7092 // TLS. So we need to adjust $tp relative addressing by this amount.
7093 Arm_address aligned_tcb_size =
7094 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7096 for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7098 Static_reloc& reloc(this->static_relocs_[i]);
7100 Arm_address value;
7101 if (!reloc.symbol_is_global())
7103 Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7104 const Symbol_value<32>* psymval =
7105 reloc.relobj()->local_symbol(reloc.index());
7107 // We are doing static linking. Issue an error and skip this
7108 // relocation if the symbol is undefined or in a discarded_section.
7109 bool is_ordinary;
7110 unsigned int shndx = psymval->input_shndx(&is_ordinary);
7111 if ((shndx == elfcpp::SHN_UNDEF)
7112 || (is_ordinary
7113 && shndx != elfcpp::SHN_UNDEF
7114 && !object->is_section_included(shndx)
7115 && !this->symbol_table_->is_section_folded(object, shndx)))
7117 gold_error(_("undefined or discarded local symbol %u from "
7118 " object %s in GOT"),
7119 reloc.index(), reloc.relobj()->name().c_str());
7120 continue;
7123 value = psymval->value(object, 0);
7125 else
7127 const Symbol* gsym = reloc.symbol();
7128 gold_assert(gsym != NULL);
7129 if (gsym->is_forwarder())
7130 gsym = this->symbol_table_->resolve_forwards(gsym);
7132 // We are doing static linking. Issue an error and skip this
7133 // relocation if the symbol is undefined or in a discarded_section
7134 // unless it is a weakly_undefined symbol.
7135 if ((gsym->is_defined_in_discarded_section()
7136 || gsym->is_undefined())
7137 && !gsym->is_weak_undefined())
7139 gold_error(_("undefined or discarded symbol %s in GOT"),
7140 gsym->name());
7141 continue;
7144 if (!gsym->is_weak_undefined())
7146 const Sized_symbol<32>* sym =
7147 static_cast<const Sized_symbol<32>*>(gsym);
7148 value = sym->value();
7150 else
7151 value = 0;
7154 unsigned got_offset = reloc.got_offset();
7155 gold_assert(got_offset < oview_size);
7157 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7158 Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7159 Valtype x;
7160 switch (reloc.r_type())
7162 case elfcpp::R_ARM_TLS_DTPOFF32:
7163 x = value;
7164 break;
7165 case elfcpp::R_ARM_TLS_TPOFF32:
7166 x = value + aligned_tcb_size;
7167 break;
7168 default:
7169 gold_unreachable();
7171 elfcpp::Swap<32, big_endian>::writeval(wv, x);
7174 of->write_output_view(offset, oview_size, oview);
7177 // A class to handle the PLT data.
7179 template<bool big_endian>
7180 class Output_data_plt_arm : public Output_section_data
7182 public:
7183 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7184 Reloc_section;
7186 Output_data_plt_arm(Layout*, Output_data_space*);
7188 // Add an entry to the PLT.
7189 void
7190 add_entry(Symbol* gsym);
7192 // Return the .rel.plt section data.
7193 const Reloc_section*
7194 rel_plt() const
7195 { return this->rel_; }
7197 // Return the number of PLT entries.
7198 unsigned int
7199 entry_count() const
7200 { return this->count_; }
7202 // Return the offset of the first non-reserved PLT entry.
7203 static unsigned int
7204 first_plt_entry_offset()
7205 { return sizeof(first_plt_entry); }
7207 // Return the size of a PLT entry.
7208 static unsigned int
7209 get_plt_entry_size()
7210 { return sizeof(plt_entry); }
7212 protected:
7213 void
7214 do_adjust_output_section(Output_section* os);
7216 // Write to a map file.
7217 void
7218 do_print_to_mapfile(Mapfile* mapfile) const
7219 { mapfile->print_output_data(this, _("** PLT")); }
7221 private:
7222 // Template for the first PLT entry.
7223 static const uint32_t first_plt_entry[5];
7225 // Template for subsequent PLT entries.
7226 static const uint32_t plt_entry[3];
7228 // Set the final size.
7229 void
7230 set_final_data_size()
7232 this->set_data_size(sizeof(first_plt_entry)
7233 + this->count_ * sizeof(plt_entry));
7236 // Write out the PLT data.
7237 void
7238 do_write(Output_file*);
7240 // The reloc section.
7241 Reloc_section* rel_;
7242 // The .got.plt section.
7243 Output_data_space* got_plt_;
7244 // The number of PLT entries.
7245 unsigned int count_;
7248 // Create the PLT section. The ordinary .got section is an argument,
7249 // since we need to refer to the start. We also create our own .got
7250 // section just for PLT entries.
7252 template<bool big_endian>
7253 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7254 Output_data_space* got_plt)
7255 : Output_section_data(4), got_plt_(got_plt), count_(0)
7257 this->rel_ = new Reloc_section(false);
7258 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7259 elfcpp::SHF_ALLOC, this->rel_,
7260 ORDER_DYNAMIC_PLT_RELOCS, false);
7263 template<bool big_endian>
7264 void
7265 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7267 os->set_entsize(0);
7270 // Add an entry to the PLT.
7272 template<bool big_endian>
7273 void
7274 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7276 gold_assert(!gsym->has_plt_offset());
7278 // Note that when setting the PLT offset we skip the initial
7279 // reserved PLT entry.
7280 gsym->set_plt_offset((this->count_) * sizeof(plt_entry)
7281 + sizeof(first_plt_entry));
7283 ++this->count_;
7285 section_offset_type got_offset = this->got_plt_->current_data_size();
7287 // Every PLT entry needs a GOT entry which points back to the PLT
7288 // entry (this will be changed by the dynamic linker, normally
7289 // lazily when the function is called).
7290 this->got_plt_->set_current_data_size(got_offset + 4);
7292 // Every PLT entry needs a reloc.
7293 gsym->set_needs_dynsym_entry();
7294 this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7295 got_offset);
7297 // Note that we don't need to save the symbol. The contents of the
7298 // PLT are independent of which symbols are used. The symbols only
7299 // appear in the relocations.
7302 // ARM PLTs.
7303 // FIXME: This is not very flexible. Right now this has only been tested
7304 // on armv5te. If we are to support additional architecture features like
7305 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7307 // The first entry in the PLT.
7308 template<bool big_endian>
7309 const uint32_t Output_data_plt_arm<big_endian>::first_plt_entry[5] =
7311 0xe52de004, // str lr, [sp, #-4]!
7312 0xe59fe004, // ldr lr, [pc, #4]
7313 0xe08fe00e, // add lr, pc, lr
7314 0xe5bef008, // ldr pc, [lr, #8]!
7315 0x00000000, // &GOT[0] - .
7318 // Subsequent entries in the PLT.
7320 template<bool big_endian>
7321 const uint32_t Output_data_plt_arm<big_endian>::plt_entry[3] =
7323 0xe28fc600, // add ip, pc, #0xNN00000
7324 0xe28cca00, // add ip, ip, #0xNN000
7325 0xe5bcf000, // ldr pc, [ip, #0xNNN]!
7328 // Write out the PLT. This uses the hand-coded instructions above,
7329 // and adjusts them as needed. This is all specified by the arm ELF
7330 // Processor Supplement.
7332 template<bool big_endian>
7333 void
7334 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7336 const off_t offset = this->offset();
7337 const section_size_type oview_size =
7338 convert_to_section_size_type(this->data_size());
7339 unsigned char* const oview = of->get_output_view(offset, oview_size);
7341 const off_t got_file_offset = this->got_plt_->offset();
7342 const section_size_type got_size =
7343 convert_to_section_size_type(this->got_plt_->data_size());
7344 unsigned char* const got_view = of->get_output_view(got_file_offset,
7345 got_size);
7346 unsigned char* pov = oview;
7348 Arm_address plt_address = this->address();
7349 Arm_address got_address = this->got_plt_->address();
7351 // Write first PLT entry. All but the last word are constants.
7352 const size_t num_first_plt_words = (sizeof(first_plt_entry)
7353 / sizeof(plt_entry[0]));
7354 for (size_t i = 0; i < num_first_plt_words - 1; i++)
7355 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7356 // Last word in first PLT entry is &GOT[0] - .
7357 elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7358 got_address - (plt_address + 16));
7359 pov += sizeof(first_plt_entry);
7361 unsigned char* got_pov = got_view;
7363 memset(got_pov, 0, 12);
7364 got_pov += 12;
7366 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
7367 unsigned int plt_offset = sizeof(first_plt_entry);
7368 unsigned int plt_rel_offset = 0;
7369 unsigned int got_offset = 12;
7370 const unsigned int count = this->count_;
7371 for (unsigned int i = 0;
7372 i < count;
7373 ++i,
7374 pov += sizeof(plt_entry),
7375 got_pov += 4,
7376 plt_offset += sizeof(plt_entry),
7377 plt_rel_offset += rel_size,
7378 got_offset += 4)
7380 // Set and adjust the PLT entry itself.
7381 int32_t offset = ((got_address + got_offset)
7382 - (plt_address + plt_offset + 8));
7384 gold_assert(offset >= 0 && offset < 0x0fffffff);
7385 uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7386 elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7387 uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7388 elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7389 uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7390 elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7392 // Set the entry in the GOT.
7393 elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7396 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7397 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7399 of->write_output_view(offset, oview_size, oview);
7400 of->write_output_view(got_file_offset, got_size, got_view);
7403 // Create a PLT entry for a global symbol.
7405 template<bool big_endian>
7406 void
7407 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7408 Symbol* gsym)
7410 if (gsym->has_plt_offset())
7411 return;
7413 if (this->plt_ == NULL)
7415 // Create the GOT sections first.
7416 this->got_section(symtab, layout);
7418 this->plt_ = new Output_data_plt_arm<big_endian>(layout, this->got_plt_);
7419 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7420 (elfcpp::SHF_ALLOC
7421 | elfcpp::SHF_EXECINSTR),
7422 this->plt_, ORDER_PLT, false);
7424 this->plt_->add_entry(gsym);
7427 // Return the number of entries in the PLT.
7429 template<bool big_endian>
7430 unsigned int
7431 Target_arm<big_endian>::plt_entry_count() const
7433 if (this->plt_ == NULL)
7434 return 0;
7435 return this->plt_->entry_count();
7438 // Return the offset of the first non-reserved PLT entry.
7440 template<bool big_endian>
7441 unsigned int
7442 Target_arm<big_endian>::first_plt_entry_offset() const
7444 return Output_data_plt_arm<big_endian>::first_plt_entry_offset();
7447 // Return the size of each PLT entry.
7449 template<bool big_endian>
7450 unsigned int
7451 Target_arm<big_endian>::plt_entry_size() const
7453 return Output_data_plt_arm<big_endian>::get_plt_entry_size();
7456 // Get the section to use for TLS_DESC relocations.
7458 template<bool big_endian>
7459 typename Target_arm<big_endian>::Reloc_section*
7460 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7462 return this->plt_section()->rel_tls_desc(layout);
7465 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7467 template<bool big_endian>
7468 void
7469 Target_arm<big_endian>::define_tls_base_symbol(
7470 Symbol_table* symtab,
7471 Layout* layout)
7473 if (this->tls_base_symbol_defined_)
7474 return;
7476 Output_segment* tls_segment = layout->tls_segment();
7477 if (tls_segment != NULL)
7479 bool is_exec = parameters->options().output_is_executable();
7480 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7481 Symbol_table::PREDEFINED,
7482 tls_segment, 0, 0,
7483 elfcpp::STT_TLS,
7484 elfcpp::STB_LOCAL,
7485 elfcpp::STV_HIDDEN, 0,
7486 (is_exec
7487 ? Symbol::SEGMENT_END
7488 : Symbol::SEGMENT_START),
7489 true);
7491 this->tls_base_symbol_defined_ = true;
7494 // Create a GOT entry for the TLS module index.
7496 template<bool big_endian>
7497 unsigned int
7498 Target_arm<big_endian>::got_mod_index_entry(
7499 Symbol_table* symtab,
7500 Layout* layout,
7501 Sized_relobj_file<32, big_endian>* object)
7503 if (this->got_mod_index_offset_ == -1U)
7505 gold_assert(symtab != NULL && layout != NULL && object != NULL);
7506 Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7507 unsigned int got_offset;
7508 if (!parameters->doing_static_link())
7510 got_offset = got->add_constant(0);
7511 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7512 rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7513 got_offset);
7515 else
7517 // We are doing a static link. Just mark it as belong to module 1,
7518 // the executable.
7519 got_offset = got->add_constant(1);
7522 got->add_constant(0);
7523 this->got_mod_index_offset_ = got_offset;
7525 return this->got_mod_index_offset_;
7528 // Optimize the TLS relocation type based on what we know about the
7529 // symbol. IS_FINAL is true if the final address of this symbol is
7530 // known at link time.
7532 template<bool big_endian>
7533 tls::Tls_optimization
7534 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7536 // FIXME: Currently we do not do any TLS optimization.
7537 return tls::TLSOPT_NONE;
7540 // Get the Reference_flags for a particular relocation.
7542 template<bool big_endian>
7544 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
7546 switch (r_type)
7548 case elfcpp::R_ARM_NONE:
7549 case elfcpp::R_ARM_V4BX:
7550 case elfcpp::R_ARM_GNU_VTENTRY:
7551 case elfcpp::R_ARM_GNU_VTINHERIT:
7552 // No symbol reference.
7553 return 0;
7555 case elfcpp::R_ARM_ABS32:
7556 case elfcpp::R_ARM_ABS16:
7557 case elfcpp::R_ARM_ABS12:
7558 case elfcpp::R_ARM_THM_ABS5:
7559 case elfcpp::R_ARM_ABS8:
7560 case elfcpp::R_ARM_BASE_ABS:
7561 case elfcpp::R_ARM_MOVW_ABS_NC:
7562 case elfcpp::R_ARM_MOVT_ABS:
7563 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7564 case elfcpp::R_ARM_THM_MOVT_ABS:
7565 case elfcpp::R_ARM_ABS32_NOI:
7566 return Symbol::ABSOLUTE_REF;
7568 case elfcpp::R_ARM_REL32:
7569 case elfcpp::R_ARM_LDR_PC_G0:
7570 case elfcpp::R_ARM_SBREL32:
7571 case elfcpp::R_ARM_THM_PC8:
7572 case elfcpp::R_ARM_BASE_PREL:
7573 case elfcpp::R_ARM_MOVW_PREL_NC:
7574 case elfcpp::R_ARM_MOVT_PREL:
7575 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7576 case elfcpp::R_ARM_THM_MOVT_PREL:
7577 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7578 case elfcpp::R_ARM_THM_PC12:
7579 case elfcpp::R_ARM_REL32_NOI:
7580 case elfcpp::R_ARM_ALU_PC_G0_NC:
7581 case elfcpp::R_ARM_ALU_PC_G0:
7582 case elfcpp::R_ARM_ALU_PC_G1_NC:
7583 case elfcpp::R_ARM_ALU_PC_G1:
7584 case elfcpp::R_ARM_ALU_PC_G2:
7585 case elfcpp::R_ARM_LDR_PC_G1:
7586 case elfcpp::R_ARM_LDR_PC_G2:
7587 case elfcpp::R_ARM_LDRS_PC_G0:
7588 case elfcpp::R_ARM_LDRS_PC_G1:
7589 case elfcpp::R_ARM_LDRS_PC_G2:
7590 case elfcpp::R_ARM_LDC_PC_G0:
7591 case elfcpp::R_ARM_LDC_PC_G1:
7592 case elfcpp::R_ARM_LDC_PC_G2:
7593 case elfcpp::R_ARM_ALU_SB_G0_NC:
7594 case elfcpp::R_ARM_ALU_SB_G0:
7595 case elfcpp::R_ARM_ALU_SB_G1_NC:
7596 case elfcpp::R_ARM_ALU_SB_G1:
7597 case elfcpp::R_ARM_ALU_SB_G2:
7598 case elfcpp::R_ARM_LDR_SB_G0:
7599 case elfcpp::R_ARM_LDR_SB_G1:
7600 case elfcpp::R_ARM_LDR_SB_G2:
7601 case elfcpp::R_ARM_LDRS_SB_G0:
7602 case elfcpp::R_ARM_LDRS_SB_G1:
7603 case elfcpp::R_ARM_LDRS_SB_G2:
7604 case elfcpp::R_ARM_LDC_SB_G0:
7605 case elfcpp::R_ARM_LDC_SB_G1:
7606 case elfcpp::R_ARM_LDC_SB_G2:
7607 case elfcpp::R_ARM_MOVW_BREL_NC:
7608 case elfcpp::R_ARM_MOVT_BREL:
7609 case elfcpp::R_ARM_MOVW_BREL:
7610 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7611 case elfcpp::R_ARM_THM_MOVT_BREL:
7612 case elfcpp::R_ARM_THM_MOVW_BREL:
7613 case elfcpp::R_ARM_GOTOFF32:
7614 case elfcpp::R_ARM_GOTOFF12:
7615 case elfcpp::R_ARM_SBREL31:
7616 return Symbol::RELATIVE_REF;
7618 case elfcpp::R_ARM_PLT32:
7619 case elfcpp::R_ARM_CALL:
7620 case elfcpp::R_ARM_JUMP24:
7621 case elfcpp::R_ARM_THM_CALL:
7622 case elfcpp::R_ARM_THM_JUMP24:
7623 case elfcpp::R_ARM_THM_JUMP19:
7624 case elfcpp::R_ARM_THM_JUMP6:
7625 case elfcpp::R_ARM_THM_JUMP11:
7626 case elfcpp::R_ARM_THM_JUMP8:
7627 // R_ARM_PREL31 is not used to relocate call/jump instructions but
7628 // in unwind tables. It may point to functions via PLTs.
7629 // So we treat it like call/jump relocations above.
7630 case elfcpp::R_ARM_PREL31:
7631 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
7633 case elfcpp::R_ARM_GOT_BREL:
7634 case elfcpp::R_ARM_GOT_ABS:
7635 case elfcpp::R_ARM_GOT_PREL:
7636 // Absolute in GOT.
7637 return Symbol::ABSOLUTE_REF;
7639 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7640 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7641 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7642 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7643 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7644 return Symbol::TLS_REF;
7646 case elfcpp::R_ARM_TARGET1:
7647 case elfcpp::R_ARM_TARGET2:
7648 case elfcpp::R_ARM_COPY:
7649 case elfcpp::R_ARM_GLOB_DAT:
7650 case elfcpp::R_ARM_JUMP_SLOT:
7651 case elfcpp::R_ARM_RELATIVE:
7652 case elfcpp::R_ARM_PC24:
7653 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7654 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7655 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7656 default:
7657 // Not expected. We will give an error later.
7658 return 0;
7662 // Report an unsupported relocation against a local symbol.
7664 template<bool big_endian>
7665 void
7666 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7667 Sized_relobj_file<32, big_endian>* object,
7668 unsigned int r_type)
7670 gold_error(_("%s: unsupported reloc %u against local symbol"),
7671 object->name().c_str(), r_type);
7674 // We are about to emit a dynamic relocation of type R_TYPE. If the
7675 // dynamic linker does not support it, issue an error. The GNU linker
7676 // only issues a non-PIC error for an allocated read-only section.
7677 // Here we know the section is allocated, but we don't know that it is
7678 // read-only. But we check for all the relocation types which the
7679 // glibc dynamic linker supports, so it seems appropriate to issue an
7680 // error even if the section is not read-only.
7682 template<bool big_endian>
7683 void
7684 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7685 unsigned int r_type)
7687 switch (r_type)
7689 // These are the relocation types supported by glibc for ARM.
7690 case elfcpp::R_ARM_RELATIVE:
7691 case elfcpp::R_ARM_COPY:
7692 case elfcpp::R_ARM_GLOB_DAT:
7693 case elfcpp::R_ARM_JUMP_SLOT:
7694 case elfcpp::R_ARM_ABS32:
7695 case elfcpp::R_ARM_ABS32_NOI:
7696 case elfcpp::R_ARM_PC24:
7697 // FIXME: The following 3 types are not supported by Android's dynamic
7698 // linker.
7699 case elfcpp::R_ARM_TLS_DTPMOD32:
7700 case elfcpp::R_ARM_TLS_DTPOFF32:
7701 case elfcpp::R_ARM_TLS_TPOFF32:
7702 return;
7704 default:
7706 // This prevents us from issuing more than one error per reloc
7707 // section. But we can still wind up issuing more than one
7708 // error per object file.
7709 if (this->issued_non_pic_error_)
7710 return;
7711 const Arm_reloc_property* reloc_property =
7712 arm_reloc_property_table->get_reloc_property(r_type);
7713 gold_assert(reloc_property != NULL);
7714 object->error(_("requires unsupported dynamic reloc %s; "
7715 "recompile with -fPIC"),
7716 reloc_property->name().c_str());
7717 this->issued_non_pic_error_ = true;
7718 return;
7721 case elfcpp::R_ARM_NONE:
7722 gold_unreachable();
7726 // Scan a relocation for a local symbol.
7727 // FIXME: This only handles a subset of relocation types used by Android
7728 // on ARM v5te devices.
7730 template<bool big_endian>
7731 inline void
7732 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7733 Layout* layout,
7734 Target_arm* target,
7735 Sized_relobj_file<32, big_endian>* object,
7736 unsigned int data_shndx,
7737 Output_section* output_section,
7738 const elfcpp::Rel<32, big_endian>& reloc,
7739 unsigned int r_type,
7740 const elfcpp::Sym<32, big_endian>& lsym)
7742 r_type = get_real_reloc_type(r_type);
7743 switch (r_type)
7745 case elfcpp::R_ARM_NONE:
7746 case elfcpp::R_ARM_V4BX:
7747 case elfcpp::R_ARM_GNU_VTENTRY:
7748 case elfcpp::R_ARM_GNU_VTINHERIT:
7749 break;
7751 case elfcpp::R_ARM_ABS32:
7752 case elfcpp::R_ARM_ABS32_NOI:
7753 // If building a shared library (or a position-independent
7754 // executable), we need to create a dynamic relocation for
7755 // this location. The relocation applied at link time will
7756 // apply the link-time value, so we flag the location with
7757 // an R_ARM_RELATIVE relocation so the dynamic loader can
7758 // relocate it easily.
7759 if (parameters->options().output_is_position_independent())
7761 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7762 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7763 // If we are to add more other reloc types than R_ARM_ABS32,
7764 // we need to add check_non_pic(object, r_type) here.
7765 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7766 output_section, data_shndx,
7767 reloc.get_r_offset());
7769 break;
7771 case elfcpp::R_ARM_ABS16:
7772 case elfcpp::R_ARM_ABS12:
7773 case elfcpp::R_ARM_THM_ABS5:
7774 case elfcpp::R_ARM_ABS8:
7775 case elfcpp::R_ARM_BASE_ABS:
7776 case elfcpp::R_ARM_MOVW_ABS_NC:
7777 case elfcpp::R_ARM_MOVT_ABS:
7778 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7779 case elfcpp::R_ARM_THM_MOVT_ABS:
7780 // If building a shared library (or a position-independent
7781 // executable), we need to create a dynamic relocation for
7782 // this location. Because the addend needs to remain in the
7783 // data section, we need to be careful not to apply this
7784 // relocation statically.
7785 if (parameters->options().output_is_position_independent())
7787 check_non_pic(object, r_type);
7788 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7789 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7790 if (lsym.get_st_type() != elfcpp::STT_SECTION)
7791 rel_dyn->add_local(object, r_sym, r_type, output_section,
7792 data_shndx, reloc.get_r_offset());
7793 else
7795 gold_assert(lsym.get_st_value() == 0);
7796 unsigned int shndx = lsym.get_st_shndx();
7797 bool is_ordinary;
7798 shndx = object->adjust_sym_shndx(r_sym, shndx,
7799 &is_ordinary);
7800 if (!is_ordinary)
7801 object->error(_("section symbol %u has bad shndx %u"),
7802 r_sym, shndx);
7803 else
7804 rel_dyn->add_local_section(object, shndx,
7805 r_type, output_section,
7806 data_shndx, reloc.get_r_offset());
7809 break;
7811 case elfcpp::R_ARM_REL32:
7812 case elfcpp::R_ARM_LDR_PC_G0:
7813 case elfcpp::R_ARM_SBREL32:
7814 case elfcpp::R_ARM_THM_CALL:
7815 case elfcpp::R_ARM_THM_PC8:
7816 case elfcpp::R_ARM_BASE_PREL:
7817 case elfcpp::R_ARM_PLT32:
7818 case elfcpp::R_ARM_CALL:
7819 case elfcpp::R_ARM_JUMP24:
7820 case elfcpp::R_ARM_THM_JUMP24:
7821 case elfcpp::R_ARM_SBREL31:
7822 case elfcpp::R_ARM_PREL31:
7823 case elfcpp::R_ARM_MOVW_PREL_NC:
7824 case elfcpp::R_ARM_MOVT_PREL:
7825 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7826 case elfcpp::R_ARM_THM_MOVT_PREL:
7827 case elfcpp::R_ARM_THM_JUMP19:
7828 case elfcpp::R_ARM_THM_JUMP6:
7829 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7830 case elfcpp::R_ARM_THM_PC12:
7831 case elfcpp::R_ARM_REL32_NOI:
7832 case elfcpp::R_ARM_ALU_PC_G0_NC:
7833 case elfcpp::R_ARM_ALU_PC_G0:
7834 case elfcpp::R_ARM_ALU_PC_G1_NC:
7835 case elfcpp::R_ARM_ALU_PC_G1:
7836 case elfcpp::R_ARM_ALU_PC_G2:
7837 case elfcpp::R_ARM_LDR_PC_G1:
7838 case elfcpp::R_ARM_LDR_PC_G2:
7839 case elfcpp::R_ARM_LDRS_PC_G0:
7840 case elfcpp::R_ARM_LDRS_PC_G1:
7841 case elfcpp::R_ARM_LDRS_PC_G2:
7842 case elfcpp::R_ARM_LDC_PC_G0:
7843 case elfcpp::R_ARM_LDC_PC_G1:
7844 case elfcpp::R_ARM_LDC_PC_G2:
7845 case elfcpp::R_ARM_ALU_SB_G0_NC:
7846 case elfcpp::R_ARM_ALU_SB_G0:
7847 case elfcpp::R_ARM_ALU_SB_G1_NC:
7848 case elfcpp::R_ARM_ALU_SB_G1:
7849 case elfcpp::R_ARM_ALU_SB_G2:
7850 case elfcpp::R_ARM_LDR_SB_G0:
7851 case elfcpp::R_ARM_LDR_SB_G1:
7852 case elfcpp::R_ARM_LDR_SB_G2:
7853 case elfcpp::R_ARM_LDRS_SB_G0:
7854 case elfcpp::R_ARM_LDRS_SB_G1:
7855 case elfcpp::R_ARM_LDRS_SB_G2:
7856 case elfcpp::R_ARM_LDC_SB_G0:
7857 case elfcpp::R_ARM_LDC_SB_G1:
7858 case elfcpp::R_ARM_LDC_SB_G2:
7859 case elfcpp::R_ARM_MOVW_BREL_NC:
7860 case elfcpp::R_ARM_MOVT_BREL:
7861 case elfcpp::R_ARM_MOVW_BREL:
7862 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7863 case elfcpp::R_ARM_THM_MOVT_BREL:
7864 case elfcpp::R_ARM_THM_MOVW_BREL:
7865 case elfcpp::R_ARM_THM_JUMP11:
7866 case elfcpp::R_ARM_THM_JUMP8:
7867 // We don't need to do anything for a relative addressing relocation
7868 // against a local symbol if it does not reference the GOT.
7869 break;
7871 case elfcpp::R_ARM_GOTOFF32:
7872 case elfcpp::R_ARM_GOTOFF12:
7873 // We need a GOT section:
7874 target->got_section(symtab, layout);
7875 break;
7877 case elfcpp::R_ARM_GOT_BREL:
7878 case elfcpp::R_ARM_GOT_PREL:
7880 // The symbol requires a GOT entry.
7881 Arm_output_data_got<big_endian>* got =
7882 target->got_section(symtab, layout);
7883 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7884 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
7886 // If we are generating a shared object, we need to add a
7887 // dynamic RELATIVE relocation for this symbol's GOT entry.
7888 if (parameters->options().output_is_position_independent())
7890 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7891 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7892 rel_dyn->add_local_relative(
7893 object, r_sym, elfcpp::R_ARM_RELATIVE, got,
7894 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
7898 break;
7900 case elfcpp::R_ARM_TARGET1:
7901 case elfcpp::R_ARM_TARGET2:
7902 // This should have been mapped to another type already.
7903 // Fall through.
7904 case elfcpp::R_ARM_COPY:
7905 case elfcpp::R_ARM_GLOB_DAT:
7906 case elfcpp::R_ARM_JUMP_SLOT:
7907 case elfcpp::R_ARM_RELATIVE:
7908 // These are relocations which should only be seen by the
7909 // dynamic linker, and should never be seen here.
7910 gold_error(_("%s: unexpected reloc %u in object file"),
7911 object->name().c_str(), r_type);
7912 break;
7915 // These are initial TLS relocs, which are expected when
7916 // linking.
7917 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7918 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7919 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7920 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7921 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7923 bool output_is_shared = parameters->options().shared();
7924 const tls::Tls_optimization optimized_type
7925 = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
7926 r_type);
7927 switch (r_type)
7929 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7930 if (optimized_type == tls::TLSOPT_NONE)
7932 // Create a pair of GOT entries for the module index and
7933 // dtv-relative offset.
7934 Arm_output_data_got<big_endian>* got
7935 = target->got_section(symtab, layout);
7936 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7937 unsigned int shndx = lsym.get_st_shndx();
7938 bool is_ordinary;
7939 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
7940 if (!is_ordinary)
7942 object->error(_("local symbol %u has bad shndx %u"),
7943 r_sym, shndx);
7944 break;
7947 if (!parameters->doing_static_link())
7948 got->add_local_pair_with_rel(object, r_sym, shndx,
7949 GOT_TYPE_TLS_PAIR,
7950 target->rel_dyn_section(layout),
7951 elfcpp::R_ARM_TLS_DTPMOD32, 0);
7952 else
7953 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
7954 object, r_sym);
7956 else
7957 // FIXME: TLS optimization not supported yet.
7958 gold_unreachable();
7959 break;
7961 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7962 if (optimized_type == tls::TLSOPT_NONE)
7964 // Create a GOT entry for the module index.
7965 target->got_mod_index_entry(symtab, layout, object);
7967 else
7968 // FIXME: TLS optimization not supported yet.
7969 gold_unreachable();
7970 break;
7972 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7973 break;
7975 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7976 layout->set_has_static_tls();
7977 if (optimized_type == tls::TLSOPT_NONE)
7979 // Create a GOT entry for the tp-relative offset.
7980 Arm_output_data_got<big_endian>* got
7981 = target->got_section(symtab, layout);
7982 unsigned int r_sym =
7983 elfcpp::elf_r_sym<32>(reloc.get_r_info());
7984 if (!parameters->doing_static_link())
7985 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
7986 target->rel_dyn_section(layout),
7987 elfcpp::R_ARM_TLS_TPOFF32);
7988 else if (!object->local_has_got_offset(r_sym,
7989 GOT_TYPE_TLS_OFFSET))
7991 got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
7992 unsigned int got_offset =
7993 object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
7994 got->add_static_reloc(got_offset,
7995 elfcpp::R_ARM_TLS_TPOFF32, object,
7996 r_sym);
7999 else
8000 // FIXME: TLS optimization not supported yet.
8001 gold_unreachable();
8002 break;
8004 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8005 layout->set_has_static_tls();
8006 if (output_is_shared)
8008 // We need to create a dynamic relocation.
8009 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8010 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8011 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8012 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8013 output_section, data_shndx,
8014 reloc.get_r_offset());
8016 break;
8018 default:
8019 gold_unreachable();
8022 break;
8024 case elfcpp::R_ARM_PC24:
8025 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8026 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8027 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8028 default:
8029 unsupported_reloc_local(object, r_type);
8030 break;
8034 // Report an unsupported relocation against a global symbol.
8036 template<bool big_endian>
8037 void
8038 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8039 Sized_relobj_file<32, big_endian>* object,
8040 unsigned int r_type,
8041 Symbol* gsym)
8043 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8044 object->name().c_str(), r_type, gsym->demangled_name().c_str());
8047 template<bool big_endian>
8048 inline bool
8049 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8050 unsigned int r_type)
8052 switch (r_type)
8054 case elfcpp::R_ARM_PC24:
8055 case elfcpp::R_ARM_THM_CALL:
8056 case elfcpp::R_ARM_PLT32:
8057 case elfcpp::R_ARM_CALL:
8058 case elfcpp::R_ARM_JUMP24:
8059 case elfcpp::R_ARM_THM_JUMP24:
8060 case elfcpp::R_ARM_SBREL31:
8061 case elfcpp::R_ARM_PREL31:
8062 case elfcpp::R_ARM_THM_JUMP19:
8063 case elfcpp::R_ARM_THM_JUMP6:
8064 case elfcpp::R_ARM_THM_JUMP11:
8065 case elfcpp::R_ARM_THM_JUMP8:
8066 // All the relocations above are branches except SBREL31 and PREL31.
8067 return false;
8069 default:
8070 // Be conservative and assume this is a function pointer.
8071 return true;
8075 template<bool big_endian>
8076 inline bool
8077 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8078 Symbol_table*,
8079 Layout*,
8080 Target_arm<big_endian>* target,
8081 Sized_relobj_file<32, big_endian>*,
8082 unsigned int,
8083 Output_section*,
8084 const elfcpp::Rel<32, big_endian>&,
8085 unsigned int r_type,
8086 const elfcpp::Sym<32, big_endian>&)
8088 r_type = target->get_real_reloc_type(r_type);
8089 return possible_function_pointer_reloc(r_type);
8092 template<bool big_endian>
8093 inline bool
8094 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8095 Symbol_table*,
8096 Layout*,
8097 Target_arm<big_endian>* target,
8098 Sized_relobj_file<32, big_endian>*,
8099 unsigned int,
8100 Output_section*,
8101 const elfcpp::Rel<32, big_endian>&,
8102 unsigned int r_type,
8103 Symbol* gsym)
8105 // GOT is not a function.
8106 if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8107 return false;
8109 r_type = target->get_real_reloc_type(r_type);
8110 return possible_function_pointer_reloc(r_type);
8113 // Scan a relocation for a global symbol.
8115 template<bool big_endian>
8116 inline void
8117 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8118 Layout* layout,
8119 Target_arm* target,
8120 Sized_relobj_file<32, big_endian>* object,
8121 unsigned int data_shndx,
8122 Output_section* output_section,
8123 const elfcpp::Rel<32, big_endian>& reloc,
8124 unsigned int r_type,
8125 Symbol* gsym)
8127 // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8128 // section. We check here to avoid creating a dynamic reloc against
8129 // _GLOBAL_OFFSET_TABLE_.
8130 if (!target->has_got_section()
8131 && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8132 target->got_section(symtab, layout);
8134 r_type = get_real_reloc_type(r_type);
8135 switch (r_type)
8137 case elfcpp::R_ARM_NONE:
8138 case elfcpp::R_ARM_V4BX:
8139 case elfcpp::R_ARM_GNU_VTENTRY:
8140 case elfcpp::R_ARM_GNU_VTINHERIT:
8141 break;
8143 case elfcpp::R_ARM_ABS32:
8144 case elfcpp::R_ARM_ABS16:
8145 case elfcpp::R_ARM_ABS12:
8146 case elfcpp::R_ARM_THM_ABS5:
8147 case elfcpp::R_ARM_ABS8:
8148 case elfcpp::R_ARM_BASE_ABS:
8149 case elfcpp::R_ARM_MOVW_ABS_NC:
8150 case elfcpp::R_ARM_MOVT_ABS:
8151 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8152 case elfcpp::R_ARM_THM_MOVT_ABS:
8153 case elfcpp::R_ARM_ABS32_NOI:
8154 // Absolute addressing relocations.
8156 // Make a PLT entry if necessary.
8157 if (this->symbol_needs_plt_entry(gsym))
8159 target->make_plt_entry(symtab, layout, gsym);
8160 // Since this is not a PC-relative relocation, we may be
8161 // taking the address of a function. In that case we need to
8162 // set the entry in the dynamic symbol table to the address of
8163 // the PLT entry.
8164 if (gsym->is_from_dynobj() && !parameters->options().shared())
8165 gsym->set_needs_dynsym_value();
8167 // Make a dynamic relocation if necessary.
8168 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8170 if (gsym->may_need_copy_reloc())
8172 target->copy_reloc(symtab, layout, object,
8173 data_shndx, output_section, gsym, reloc);
8175 else if ((r_type == elfcpp::R_ARM_ABS32
8176 || r_type == elfcpp::R_ARM_ABS32_NOI)
8177 && gsym->can_use_relative_reloc(false))
8179 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8180 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8181 output_section, object,
8182 data_shndx, reloc.get_r_offset());
8184 else
8186 check_non_pic(object, r_type);
8187 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8188 rel_dyn->add_global(gsym, r_type, output_section, object,
8189 data_shndx, reloc.get_r_offset());
8193 break;
8195 case elfcpp::R_ARM_GOTOFF32:
8196 case elfcpp::R_ARM_GOTOFF12:
8197 // We need a GOT section.
8198 target->got_section(symtab, layout);
8199 break;
8201 case elfcpp::R_ARM_REL32:
8202 case elfcpp::R_ARM_LDR_PC_G0:
8203 case elfcpp::R_ARM_SBREL32:
8204 case elfcpp::R_ARM_THM_PC8:
8205 case elfcpp::R_ARM_BASE_PREL:
8206 case elfcpp::R_ARM_MOVW_PREL_NC:
8207 case elfcpp::R_ARM_MOVT_PREL:
8208 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8209 case elfcpp::R_ARM_THM_MOVT_PREL:
8210 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8211 case elfcpp::R_ARM_THM_PC12:
8212 case elfcpp::R_ARM_REL32_NOI:
8213 case elfcpp::R_ARM_ALU_PC_G0_NC:
8214 case elfcpp::R_ARM_ALU_PC_G0:
8215 case elfcpp::R_ARM_ALU_PC_G1_NC:
8216 case elfcpp::R_ARM_ALU_PC_G1:
8217 case elfcpp::R_ARM_ALU_PC_G2:
8218 case elfcpp::R_ARM_LDR_PC_G1:
8219 case elfcpp::R_ARM_LDR_PC_G2:
8220 case elfcpp::R_ARM_LDRS_PC_G0:
8221 case elfcpp::R_ARM_LDRS_PC_G1:
8222 case elfcpp::R_ARM_LDRS_PC_G2:
8223 case elfcpp::R_ARM_LDC_PC_G0:
8224 case elfcpp::R_ARM_LDC_PC_G1:
8225 case elfcpp::R_ARM_LDC_PC_G2:
8226 case elfcpp::R_ARM_ALU_SB_G0_NC:
8227 case elfcpp::R_ARM_ALU_SB_G0:
8228 case elfcpp::R_ARM_ALU_SB_G1_NC:
8229 case elfcpp::R_ARM_ALU_SB_G1:
8230 case elfcpp::R_ARM_ALU_SB_G2:
8231 case elfcpp::R_ARM_LDR_SB_G0:
8232 case elfcpp::R_ARM_LDR_SB_G1:
8233 case elfcpp::R_ARM_LDR_SB_G2:
8234 case elfcpp::R_ARM_LDRS_SB_G0:
8235 case elfcpp::R_ARM_LDRS_SB_G1:
8236 case elfcpp::R_ARM_LDRS_SB_G2:
8237 case elfcpp::R_ARM_LDC_SB_G0:
8238 case elfcpp::R_ARM_LDC_SB_G1:
8239 case elfcpp::R_ARM_LDC_SB_G2:
8240 case elfcpp::R_ARM_MOVW_BREL_NC:
8241 case elfcpp::R_ARM_MOVT_BREL:
8242 case elfcpp::R_ARM_MOVW_BREL:
8243 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8244 case elfcpp::R_ARM_THM_MOVT_BREL:
8245 case elfcpp::R_ARM_THM_MOVW_BREL:
8246 // Relative addressing relocations.
8248 // Make a dynamic relocation if necessary.
8249 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8251 if (target->may_need_copy_reloc(gsym))
8253 target->copy_reloc(symtab, layout, object,
8254 data_shndx, output_section, gsym, reloc);
8256 else
8258 check_non_pic(object, r_type);
8259 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8260 rel_dyn->add_global(gsym, r_type, output_section, object,
8261 data_shndx, reloc.get_r_offset());
8265 break;
8267 case elfcpp::R_ARM_THM_CALL:
8268 case elfcpp::R_ARM_PLT32:
8269 case elfcpp::R_ARM_CALL:
8270 case elfcpp::R_ARM_JUMP24:
8271 case elfcpp::R_ARM_THM_JUMP24:
8272 case elfcpp::R_ARM_SBREL31:
8273 case elfcpp::R_ARM_PREL31:
8274 case elfcpp::R_ARM_THM_JUMP19:
8275 case elfcpp::R_ARM_THM_JUMP6:
8276 case elfcpp::R_ARM_THM_JUMP11:
8277 case elfcpp::R_ARM_THM_JUMP8:
8278 // All the relocation above are branches except for the PREL31 ones.
8279 // A PREL31 relocation can point to a personality function in a shared
8280 // library. In that case we want to use a PLT because we want to
8281 // call the personality routine and the dynamic linkers we care about
8282 // do not support dynamic PREL31 relocations. An REL31 relocation may
8283 // point to a function whose unwinding behaviour is being described but
8284 // we will not mistakenly generate a PLT for that because we should use
8285 // a local section symbol.
8287 // If the symbol is fully resolved, this is just a relative
8288 // local reloc. Otherwise we need a PLT entry.
8289 if (gsym->final_value_is_known())
8290 break;
8291 // If building a shared library, we can also skip the PLT entry
8292 // if the symbol is defined in the output file and is protected
8293 // or hidden.
8294 if (gsym->is_defined()
8295 && !gsym->is_from_dynobj()
8296 && !gsym->is_preemptible())
8297 break;
8298 target->make_plt_entry(symtab, layout, gsym);
8299 break;
8301 case elfcpp::R_ARM_GOT_BREL:
8302 case elfcpp::R_ARM_GOT_ABS:
8303 case elfcpp::R_ARM_GOT_PREL:
8305 // The symbol requires a GOT entry.
8306 Arm_output_data_got<big_endian>* got =
8307 target->got_section(symtab, layout);
8308 if (gsym->final_value_is_known())
8309 got->add_global(gsym, GOT_TYPE_STANDARD);
8310 else
8312 // If this symbol is not fully resolved, we need to add a
8313 // GOT entry with a dynamic relocation.
8314 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8315 if (gsym->is_from_dynobj()
8316 || gsym->is_undefined()
8317 || gsym->is_preemptible())
8318 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8319 rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8320 else
8322 if (got->add_global(gsym, GOT_TYPE_STANDARD))
8323 rel_dyn->add_global_relative(
8324 gsym, elfcpp::R_ARM_RELATIVE, got,
8325 gsym->got_offset(GOT_TYPE_STANDARD));
8329 break;
8331 case elfcpp::R_ARM_TARGET1:
8332 case elfcpp::R_ARM_TARGET2:
8333 // These should have been mapped to other types already.
8334 // Fall through.
8335 case elfcpp::R_ARM_COPY:
8336 case elfcpp::R_ARM_GLOB_DAT:
8337 case elfcpp::R_ARM_JUMP_SLOT:
8338 case elfcpp::R_ARM_RELATIVE:
8339 // These are relocations which should only be seen by the
8340 // dynamic linker, and should never be seen here.
8341 gold_error(_("%s: unexpected reloc %u in object file"),
8342 object->name().c_str(), r_type);
8343 break;
8345 // These are initial tls relocs, which are expected when
8346 // linking.
8347 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8348 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8349 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8350 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8351 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8353 const bool is_final = gsym->final_value_is_known();
8354 const tls::Tls_optimization optimized_type
8355 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8356 switch (r_type)
8358 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8359 if (optimized_type == tls::TLSOPT_NONE)
8361 // Create a pair of GOT entries for the module index and
8362 // dtv-relative offset.
8363 Arm_output_data_got<big_endian>* got
8364 = target->got_section(symtab, layout);
8365 if (!parameters->doing_static_link())
8366 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8367 target->rel_dyn_section(layout),
8368 elfcpp::R_ARM_TLS_DTPMOD32,
8369 elfcpp::R_ARM_TLS_DTPOFF32);
8370 else
8371 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8373 else
8374 // FIXME: TLS optimization not supported yet.
8375 gold_unreachable();
8376 break;
8378 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8379 if (optimized_type == tls::TLSOPT_NONE)
8381 // Create a GOT entry for the module index.
8382 target->got_mod_index_entry(symtab, layout, object);
8384 else
8385 // FIXME: TLS optimization not supported yet.
8386 gold_unreachable();
8387 break;
8389 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8390 break;
8392 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8393 layout->set_has_static_tls();
8394 if (optimized_type == tls::TLSOPT_NONE)
8396 // Create a GOT entry for the tp-relative offset.
8397 Arm_output_data_got<big_endian>* got
8398 = target->got_section(symtab, layout);
8399 if (!parameters->doing_static_link())
8400 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
8401 target->rel_dyn_section(layout),
8402 elfcpp::R_ARM_TLS_TPOFF32);
8403 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
8405 got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
8406 unsigned int got_offset =
8407 gsym->got_offset(GOT_TYPE_TLS_OFFSET);
8408 got->add_static_reloc(got_offset,
8409 elfcpp::R_ARM_TLS_TPOFF32, gsym);
8412 else
8413 // FIXME: TLS optimization not supported yet.
8414 gold_unreachable();
8415 break;
8417 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8418 layout->set_has_static_tls();
8419 if (parameters->options().shared())
8421 // We need to create a dynamic relocation.
8422 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8423 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
8424 output_section, object,
8425 data_shndx, reloc.get_r_offset());
8427 break;
8429 default:
8430 gold_unreachable();
8433 break;
8435 case elfcpp::R_ARM_PC24:
8436 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8437 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8438 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8439 default:
8440 unsupported_reloc_global(object, r_type, gsym);
8441 break;
8445 // Process relocations for gc.
8447 template<bool big_endian>
8448 void
8449 Target_arm<big_endian>::gc_process_relocs(
8450 Symbol_table* symtab,
8451 Layout* layout,
8452 Sized_relobj_file<32, big_endian>* object,
8453 unsigned int data_shndx,
8454 unsigned int,
8455 const unsigned char* prelocs,
8456 size_t reloc_count,
8457 Output_section* output_section,
8458 bool needs_special_offset_handling,
8459 size_t local_symbol_count,
8460 const unsigned char* plocal_symbols)
8462 typedef Target_arm<big_endian> Arm;
8463 typedef typename Target_arm<big_endian>::Scan Scan;
8465 gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
8466 typename Target_arm::Relocatable_size_for_reloc>(
8467 symtab,
8468 layout,
8469 this,
8470 object,
8471 data_shndx,
8472 prelocs,
8473 reloc_count,
8474 output_section,
8475 needs_special_offset_handling,
8476 local_symbol_count,
8477 plocal_symbols);
8480 // Scan relocations for a section.
8482 template<bool big_endian>
8483 void
8484 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
8485 Layout* layout,
8486 Sized_relobj_file<32, big_endian>* object,
8487 unsigned int data_shndx,
8488 unsigned int sh_type,
8489 const unsigned char* prelocs,
8490 size_t reloc_count,
8491 Output_section* output_section,
8492 bool needs_special_offset_handling,
8493 size_t local_symbol_count,
8494 const unsigned char* plocal_symbols)
8496 typedef typename Target_arm<big_endian>::Scan Scan;
8497 if (sh_type == elfcpp::SHT_RELA)
8499 gold_error(_("%s: unsupported RELA reloc section"),
8500 object->name().c_str());
8501 return;
8504 gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
8505 symtab,
8506 layout,
8507 this,
8508 object,
8509 data_shndx,
8510 prelocs,
8511 reloc_count,
8512 output_section,
8513 needs_special_offset_handling,
8514 local_symbol_count,
8515 plocal_symbols);
8518 // Finalize the sections.
8520 template<bool big_endian>
8521 void
8522 Target_arm<big_endian>::do_finalize_sections(
8523 Layout* layout,
8524 const Input_objects* input_objects,
8525 Symbol_table* symtab)
8527 bool merged_any_attributes = false;
8528 // Merge processor-specific flags.
8529 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
8530 p != input_objects->relobj_end();
8531 ++p)
8533 Arm_relobj<big_endian>* arm_relobj =
8534 Arm_relobj<big_endian>::as_arm_relobj(*p);
8535 if (arm_relobj->merge_flags_and_attributes())
8537 this->merge_processor_specific_flags(
8538 arm_relobj->name(),
8539 arm_relobj->processor_specific_flags());
8540 this->merge_object_attributes(arm_relobj->name().c_str(),
8541 arm_relobj->attributes_section_data());
8542 merged_any_attributes = true;
8546 for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
8547 p != input_objects->dynobj_end();
8548 ++p)
8550 Arm_dynobj<big_endian>* arm_dynobj =
8551 Arm_dynobj<big_endian>::as_arm_dynobj(*p);
8552 this->merge_processor_specific_flags(
8553 arm_dynobj->name(),
8554 arm_dynobj->processor_specific_flags());
8555 this->merge_object_attributes(arm_dynobj->name().c_str(),
8556 arm_dynobj->attributes_section_data());
8557 merged_any_attributes = true;
8560 // Create an empty uninitialized attribute section if we still don't have it
8561 // at this moment. This happens if there is no attributes sections in all
8562 // inputs.
8563 if (this->attributes_section_data_ == NULL)
8564 this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
8566 const Object_attribute* cpu_arch_attr =
8567 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
8568 // Check if we need to use Cortex-A8 workaround.
8569 if (parameters->options().user_set_fix_cortex_a8())
8570 this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
8571 else
8573 // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
8574 // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
8575 // profile.
8576 const Object_attribute* cpu_arch_profile_attr =
8577 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
8578 this->fix_cortex_a8_ =
8579 (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
8580 && (cpu_arch_profile_attr->int_value() == 'A'
8581 || cpu_arch_profile_attr->int_value() == 0));
8584 // Check if we can use V4BX interworking.
8585 // The V4BX interworking stub contains BX instruction,
8586 // which is not specified for some profiles.
8587 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
8588 && !this->may_use_v4t_interworking())
8589 gold_error(_("unable to provide V4BX reloc interworking fix up; "
8590 "the target profile does not support BX instruction"));
8592 // Fill in some more dynamic tags.
8593 const Reloc_section* rel_plt = (this->plt_ == NULL
8594 ? NULL
8595 : this->plt_->rel_plt());
8596 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
8597 this->rel_dyn_, true, false);
8599 // Emit any relocs we saved in an attempt to avoid generating COPY
8600 // relocs.
8601 if (this->copy_relocs_.any_saved_relocs())
8602 this->copy_relocs_.emit(this->rel_dyn_section(layout));
8604 // Handle the .ARM.exidx section.
8605 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8607 if (!parameters->options().relocatable())
8609 if (exidx_section != NULL
8610 && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
8612 // Create __exidx_start and __exidx_end symbols.
8613 symtab->define_in_output_data("__exidx_start", NULL,
8614 Symbol_table::PREDEFINED,
8615 exidx_section, 0, 0, elfcpp::STT_OBJECT,
8616 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
8617 0, false, true);
8618 symtab->define_in_output_data("__exidx_end", NULL,
8619 Symbol_table::PREDEFINED,
8620 exidx_section, 0, 0, elfcpp::STT_OBJECT,
8621 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
8622 0, true, true);
8624 // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8625 // the .ARM.exidx section.
8626 if (!layout->script_options()->saw_phdrs_clause())
8628 gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
8630 == NULL);
8631 Output_segment* exidx_segment =
8632 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8633 exidx_segment->add_output_section_to_nonload(exidx_section,
8634 elfcpp::PF_R);
8637 else
8639 symtab->define_as_constant("__exidx_start", NULL,
8640 Symbol_table::PREDEFINED,
8641 0, 0, elfcpp::STT_OBJECT,
8642 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8643 true, false);
8644 symtab->define_as_constant("__exidx_end", NULL,
8645 Symbol_table::PREDEFINED,
8646 0, 0, elfcpp::STT_OBJECT,
8647 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8648 true, false);
8652 // Create an .ARM.attributes section if we have merged any attributes
8653 // from inputs.
8654 if (merged_any_attributes)
8656 Output_attributes_section_data* attributes_section =
8657 new Output_attributes_section_data(*this->attributes_section_data_);
8658 layout->add_output_section_data(".ARM.attributes",
8659 elfcpp::SHT_ARM_ATTRIBUTES, 0,
8660 attributes_section, ORDER_INVALID,
8661 false);
8664 // Fix up links in section EXIDX headers.
8665 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
8666 p != layout->section_list().end();
8667 ++p)
8668 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
8670 Arm_output_section<big_endian>* os =
8671 Arm_output_section<big_endian>::as_arm_output_section(*p);
8672 os->set_exidx_section_link();
8676 // Return whether a direct absolute static relocation needs to be applied.
8677 // In cases where Scan::local() or Scan::global() has created
8678 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8679 // of the relocation is carried in the data, and we must not
8680 // apply the static relocation.
8682 template<bool big_endian>
8683 inline bool
8684 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8685 const Sized_symbol<32>* gsym,
8686 unsigned int r_type,
8687 bool is_32bit,
8688 Output_section* output_section)
8690 // If the output section is not allocated, then we didn't call
8691 // scan_relocs, we didn't create a dynamic reloc, and we must apply
8692 // the reloc here.
8693 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8694 return true;
8696 int ref_flags = Scan::get_reference_flags(r_type);
8698 // For local symbols, we will have created a non-RELATIVE dynamic
8699 // relocation only if (a) the output is position independent,
8700 // (b) the relocation is absolute (not pc- or segment-relative), and
8701 // (c) the relocation is not 32 bits wide.
8702 if (gsym == NULL)
8703 return !(parameters->options().output_is_position_independent()
8704 && (ref_flags & Symbol::ABSOLUTE_REF)
8705 && !is_32bit);
8707 // For global symbols, we use the same helper routines used in the
8708 // scan pass. If we did not create a dynamic relocation, or if we
8709 // created a RELATIVE dynamic relocation, we should apply the static
8710 // relocation.
8711 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8712 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8713 && gsym->can_use_relative_reloc(ref_flags
8714 & Symbol::FUNCTION_CALL);
8715 return !has_dyn || is_rel;
8718 // Perform a relocation.
8720 template<bool big_endian>
8721 inline bool
8722 Target_arm<big_endian>::Relocate::relocate(
8723 const Relocate_info<32, big_endian>* relinfo,
8724 Target_arm* target,
8725 Output_section* output_section,
8726 size_t relnum,
8727 const elfcpp::Rel<32, big_endian>& rel,
8728 unsigned int r_type,
8729 const Sized_symbol<32>* gsym,
8730 const Symbol_value<32>* psymval,
8731 unsigned char* view,
8732 Arm_address address,
8733 section_size_type view_size)
8735 typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8737 r_type = get_real_reloc_type(r_type);
8738 const Arm_reloc_property* reloc_property =
8739 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8740 if (reloc_property == NULL)
8742 std::string reloc_name =
8743 arm_reloc_property_table->reloc_name_in_error_message(r_type);
8744 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8745 _("cannot relocate %s in object file"),
8746 reloc_name.c_str());
8747 return true;
8750 const Arm_relobj<big_endian>* object =
8751 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8753 // If the final branch target of a relocation is THUMB instruction, this
8754 // is 1. Otherwise it is 0.
8755 Arm_address thumb_bit = 0;
8756 Symbol_value<32> symval;
8757 bool is_weakly_undefined_without_plt = false;
8758 bool have_got_offset = false;
8759 unsigned int got_offset = 0;
8761 // If the relocation uses the GOT entry of a symbol instead of the symbol
8762 // itself, we don't care about whether the symbol is defined or what kind
8763 // of symbol it is.
8764 if (reloc_property->uses_got_entry())
8766 // Get the GOT offset.
8767 // The GOT pointer points to the end of the GOT section.
8768 // We need to subtract the size of the GOT section to get
8769 // the actual offset to use in the relocation.
8770 // TODO: We should move GOT offset computing code in TLS relocations
8771 // to here.
8772 switch (r_type)
8774 case elfcpp::R_ARM_GOT_BREL:
8775 case elfcpp::R_ARM_GOT_PREL:
8776 if (gsym != NULL)
8778 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8779 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8780 - target->got_size());
8782 else
8784 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8785 gold_assert(object->local_has_got_offset(r_sym,
8786 GOT_TYPE_STANDARD));
8787 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8788 - target->got_size());
8790 have_got_offset = true;
8791 break;
8793 default:
8794 break;
8797 else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8799 if (gsym != NULL)
8801 // This is a global symbol. Determine if we use PLT and if the
8802 // final target is THUMB.
8803 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
8805 // This uses a PLT, change the symbol value.
8806 symval.set_output_value(target->plt_section()->address()
8807 + gsym->plt_offset());
8808 psymval = &symval;
8810 else if (gsym->is_weak_undefined())
8812 // This is a weakly undefined symbol and we do not use PLT
8813 // for this relocation. A branch targeting this symbol will
8814 // be converted into an NOP.
8815 is_weakly_undefined_without_plt = true;
8817 else if (gsym->is_undefined() && reloc_property->uses_symbol())
8819 // This relocation uses the symbol value but the symbol is
8820 // undefined. Exit early and have the caller reporting an
8821 // error.
8822 return true;
8824 else
8826 // Set thumb bit if symbol:
8827 // -Has type STT_ARM_TFUNC or
8828 // -Has type STT_FUNC, is defined and with LSB in value set.
8829 thumb_bit =
8830 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8831 || (gsym->type() == elfcpp::STT_FUNC
8832 && !gsym->is_undefined()
8833 && ((psymval->value(object, 0) & 1) != 0)))
8835 : 0);
8838 else
8840 // This is a local symbol. Determine if the final target is THUMB.
8841 // We saved this information when all the local symbols were read.
8842 elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8843 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8844 thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8847 else
8849 // This is a fake relocation synthesized for a stub. It does not have
8850 // a real symbol. We just look at the LSB of the symbol value to
8851 // determine if the target is THUMB or not.
8852 thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8855 // Strip LSB if this points to a THUMB target.
8856 if (thumb_bit != 0
8857 && reloc_property->uses_thumb_bit()
8858 && ((psymval->value(object, 0) & 1) != 0))
8860 Arm_address stripped_value =
8861 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8862 symval.set_output_value(stripped_value);
8863 psymval = &symval;
8866 // To look up relocation stubs, we need to pass the symbol table index of
8867 // a local symbol.
8868 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8870 // Get the addressing origin of the output segment defining the
8871 // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8872 Arm_address sym_origin = 0;
8873 if (reloc_property->uses_symbol_base())
8875 if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8876 // R_ARM_BASE_ABS with the NULL symbol will give the
8877 // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8878 // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8879 sym_origin = target->got_plt_section()->address();
8880 else if (gsym == NULL)
8881 sym_origin = 0;
8882 else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8883 sym_origin = gsym->output_segment()->vaddr();
8884 else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
8885 sym_origin = gsym->output_data()->address();
8887 // TODO: Assumes the segment base to be zero for the global symbols
8888 // till the proper support for the segment-base-relative addressing
8889 // will be implemented. This is consistent with GNU ld.
8892 // For relative addressing relocation, find out the relative address base.
8893 Arm_address relative_address_base = 0;
8894 switch(reloc_property->relative_address_base())
8896 case Arm_reloc_property::RAB_NONE:
8897 // Relocations with relative address bases RAB_TLS and RAB_tp are
8898 // handled by relocate_tls. So we do not need to do anything here.
8899 case Arm_reloc_property::RAB_TLS:
8900 case Arm_reloc_property::RAB_tp:
8901 break;
8902 case Arm_reloc_property::RAB_B_S:
8903 relative_address_base = sym_origin;
8904 break;
8905 case Arm_reloc_property::RAB_GOT_ORG:
8906 relative_address_base = target->got_plt_section()->address();
8907 break;
8908 case Arm_reloc_property::RAB_P:
8909 relative_address_base = address;
8910 break;
8911 case Arm_reloc_property::RAB_Pa:
8912 relative_address_base = address & 0xfffffffcU;
8913 break;
8914 default:
8915 gold_unreachable();
8918 typename Arm_relocate_functions::Status reloc_status =
8919 Arm_relocate_functions::STATUS_OKAY;
8920 bool check_overflow = reloc_property->checks_overflow();
8921 switch (r_type)
8923 case elfcpp::R_ARM_NONE:
8924 break;
8926 case elfcpp::R_ARM_ABS8:
8927 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8928 reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
8929 break;
8931 case elfcpp::R_ARM_ABS12:
8932 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8933 reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
8934 break;
8936 case elfcpp::R_ARM_ABS16:
8937 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8938 reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
8939 break;
8941 case elfcpp::R_ARM_ABS32:
8942 if (should_apply_static_reloc(gsym, r_type, true, output_section))
8943 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8944 thumb_bit);
8945 break;
8947 case elfcpp::R_ARM_ABS32_NOI:
8948 if (should_apply_static_reloc(gsym, r_type, true, output_section))
8949 // No thumb bit for this relocation: (S + A)
8950 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8952 break;
8954 case elfcpp::R_ARM_MOVW_ABS_NC:
8955 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8956 reloc_status = Arm_relocate_functions::movw(view, object, psymval,
8957 0, thumb_bit,
8958 check_overflow);
8959 break;
8961 case elfcpp::R_ARM_MOVT_ABS:
8962 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8963 reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
8964 break;
8966 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8967 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8968 reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
8969 0, thumb_bit, false);
8970 break;
8972 case elfcpp::R_ARM_THM_MOVT_ABS:
8973 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8974 reloc_status = Arm_relocate_functions::thm_movt(view, object,
8975 psymval, 0);
8976 break;
8978 case elfcpp::R_ARM_MOVW_PREL_NC:
8979 case elfcpp::R_ARM_MOVW_BREL_NC:
8980 case elfcpp::R_ARM_MOVW_BREL:
8981 reloc_status =
8982 Arm_relocate_functions::movw(view, object, psymval,
8983 relative_address_base, thumb_bit,
8984 check_overflow);
8985 break;
8987 case elfcpp::R_ARM_MOVT_PREL:
8988 case elfcpp::R_ARM_MOVT_BREL:
8989 reloc_status =
8990 Arm_relocate_functions::movt(view, object, psymval,
8991 relative_address_base);
8992 break;
8994 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8995 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8996 case elfcpp::R_ARM_THM_MOVW_BREL:
8997 reloc_status =
8998 Arm_relocate_functions::thm_movw(view, object, psymval,
8999 relative_address_base,
9000 thumb_bit, check_overflow);
9001 break;
9003 case elfcpp::R_ARM_THM_MOVT_PREL:
9004 case elfcpp::R_ARM_THM_MOVT_BREL:
9005 reloc_status =
9006 Arm_relocate_functions::thm_movt(view, object, psymval,
9007 relative_address_base);
9008 break;
9010 case elfcpp::R_ARM_REL32:
9011 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9012 address, thumb_bit);
9013 break;
9015 case elfcpp::R_ARM_THM_ABS5:
9016 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9017 reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
9018 break;
9020 // Thumb long branches.
9021 case elfcpp::R_ARM_THM_CALL:
9022 case elfcpp::R_ARM_THM_XPC22:
9023 case elfcpp::R_ARM_THM_JUMP24:
9024 reloc_status =
9025 Arm_relocate_functions::thumb_branch_common(
9026 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9027 thumb_bit, is_weakly_undefined_without_plt);
9028 break;
9030 case elfcpp::R_ARM_GOTOFF32:
9032 Arm_address got_origin;
9033 got_origin = target->got_plt_section()->address();
9034 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9035 got_origin, thumb_bit);
9037 break;
9039 case elfcpp::R_ARM_BASE_PREL:
9040 gold_assert(gsym != NULL);
9041 reloc_status =
9042 Arm_relocate_functions::base_prel(view, sym_origin, address);
9043 break;
9045 case elfcpp::R_ARM_BASE_ABS:
9046 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9047 reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
9048 break;
9050 case elfcpp::R_ARM_GOT_BREL:
9051 gold_assert(have_got_offset);
9052 reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
9053 break;
9055 case elfcpp::R_ARM_GOT_PREL:
9056 gold_assert(have_got_offset);
9057 // Get the address origin for GOT PLT, which is allocated right
9058 // after the GOT section, to calculate an absolute address of
9059 // the symbol GOT entry (got_origin + got_offset).
9060 Arm_address got_origin;
9061 got_origin = target->got_plt_section()->address();
9062 reloc_status = Arm_relocate_functions::got_prel(view,
9063 got_origin + got_offset,
9064 address);
9065 break;
9067 case elfcpp::R_ARM_PLT32:
9068 case elfcpp::R_ARM_CALL:
9069 case elfcpp::R_ARM_JUMP24:
9070 case elfcpp::R_ARM_XPC25:
9071 gold_assert(gsym == NULL
9072 || gsym->has_plt_offset()
9073 || gsym->final_value_is_known()
9074 || (gsym->is_defined()
9075 && !gsym->is_from_dynobj()
9076 && !gsym->is_preemptible()));
9077 reloc_status =
9078 Arm_relocate_functions::arm_branch_common(
9079 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9080 thumb_bit, is_weakly_undefined_without_plt);
9081 break;
9083 case elfcpp::R_ARM_THM_JUMP19:
9084 reloc_status =
9085 Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9086 thumb_bit);
9087 break;
9089 case elfcpp::R_ARM_THM_JUMP6:
9090 reloc_status =
9091 Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9092 break;
9094 case elfcpp::R_ARM_THM_JUMP8:
9095 reloc_status =
9096 Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9097 break;
9099 case elfcpp::R_ARM_THM_JUMP11:
9100 reloc_status =
9101 Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9102 break;
9104 case elfcpp::R_ARM_PREL31:
9105 reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9106 address, thumb_bit);
9107 break;
9109 case elfcpp::R_ARM_V4BX:
9110 if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9112 const bool is_v4bx_interworking =
9113 (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9114 reloc_status =
9115 Arm_relocate_functions::v4bx(relinfo, view, object, address,
9116 is_v4bx_interworking);
9118 break;
9120 case elfcpp::R_ARM_THM_PC8:
9121 reloc_status =
9122 Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9123 break;
9125 case elfcpp::R_ARM_THM_PC12:
9126 reloc_status =
9127 Arm_relocate_functions::thm_pc12(view, object, psymval, address);
9128 break;
9130 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9131 reloc_status =
9132 Arm_relocate_functions::thm_alu11(view, object, psymval, address,
9133 thumb_bit);
9134 break;
9136 case elfcpp::R_ARM_ALU_PC_G0_NC:
9137 case elfcpp::R_ARM_ALU_PC_G0:
9138 case elfcpp::R_ARM_ALU_PC_G1_NC:
9139 case elfcpp::R_ARM_ALU_PC_G1:
9140 case elfcpp::R_ARM_ALU_PC_G2:
9141 case elfcpp::R_ARM_ALU_SB_G0_NC:
9142 case elfcpp::R_ARM_ALU_SB_G0:
9143 case elfcpp::R_ARM_ALU_SB_G1_NC:
9144 case elfcpp::R_ARM_ALU_SB_G1:
9145 case elfcpp::R_ARM_ALU_SB_G2:
9146 reloc_status =
9147 Arm_relocate_functions::arm_grp_alu(view, object, psymval,
9148 reloc_property->group_index(),
9149 relative_address_base,
9150 thumb_bit, check_overflow);
9151 break;
9153 case elfcpp::R_ARM_LDR_PC_G0:
9154 case elfcpp::R_ARM_LDR_PC_G1:
9155 case elfcpp::R_ARM_LDR_PC_G2:
9156 case elfcpp::R_ARM_LDR_SB_G0:
9157 case elfcpp::R_ARM_LDR_SB_G1:
9158 case elfcpp::R_ARM_LDR_SB_G2:
9159 reloc_status =
9160 Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9161 reloc_property->group_index(),
9162 relative_address_base);
9163 break;
9165 case elfcpp::R_ARM_LDRS_PC_G0:
9166 case elfcpp::R_ARM_LDRS_PC_G1:
9167 case elfcpp::R_ARM_LDRS_PC_G2:
9168 case elfcpp::R_ARM_LDRS_SB_G0:
9169 case elfcpp::R_ARM_LDRS_SB_G1:
9170 case elfcpp::R_ARM_LDRS_SB_G2:
9171 reloc_status =
9172 Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9173 reloc_property->group_index(),
9174 relative_address_base);
9175 break;
9177 case elfcpp::R_ARM_LDC_PC_G0:
9178 case elfcpp::R_ARM_LDC_PC_G1:
9179 case elfcpp::R_ARM_LDC_PC_G2:
9180 case elfcpp::R_ARM_LDC_SB_G0:
9181 case elfcpp::R_ARM_LDC_SB_G1:
9182 case elfcpp::R_ARM_LDC_SB_G2:
9183 reloc_status =
9184 Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9185 reloc_property->group_index(),
9186 relative_address_base);
9187 break;
9189 // These are initial tls relocs, which are expected when
9190 // linking.
9191 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9192 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9193 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9194 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9195 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9196 reloc_status =
9197 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9198 view, address, view_size);
9199 break;
9201 // The known and unknown unsupported and/or deprecated relocations.
9202 case elfcpp::R_ARM_PC24:
9203 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9204 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9205 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9206 default:
9207 // Just silently leave the method. We should get an appropriate error
9208 // message in the scan methods.
9209 break;
9212 // Report any errors.
9213 switch (reloc_status)
9215 case Arm_relocate_functions::STATUS_OKAY:
9216 break;
9217 case Arm_relocate_functions::STATUS_OVERFLOW:
9218 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9219 _("relocation overflow in %s"),
9220 reloc_property->name().c_str());
9221 break;
9222 case Arm_relocate_functions::STATUS_BAD_RELOC:
9223 gold_error_at_location(
9224 relinfo,
9225 relnum,
9226 rel.get_r_offset(),
9227 _("unexpected opcode while processing relocation %s"),
9228 reloc_property->name().c_str());
9229 break;
9230 default:
9231 gold_unreachable();
9234 return true;
9237 // Perform a TLS relocation.
9239 template<bool big_endian>
9240 inline typename Arm_relocate_functions<big_endian>::Status
9241 Target_arm<big_endian>::Relocate::relocate_tls(
9242 const Relocate_info<32, big_endian>* relinfo,
9243 Target_arm<big_endian>* target,
9244 size_t relnum,
9245 const elfcpp::Rel<32, big_endian>& rel,
9246 unsigned int r_type,
9247 const Sized_symbol<32>* gsym,
9248 const Symbol_value<32>* psymval,
9249 unsigned char* view,
9250 elfcpp::Elf_types<32>::Elf_Addr address,
9251 section_size_type /*view_size*/ )
9253 typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9254 typedef Relocate_functions<32, big_endian> RelocFuncs;
9255 Output_segment* tls_segment = relinfo->layout->tls_segment();
9257 const Sized_relobj_file<32, big_endian>* object = relinfo->object;
9259 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9261 const bool is_final = (gsym == NULL
9262 ? !parameters->options().shared()
9263 : gsym->final_value_is_known());
9264 const tls::Tls_optimization optimized_type
9265 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9266 switch (r_type)
9268 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9270 unsigned int got_type = GOT_TYPE_TLS_PAIR;
9271 unsigned int got_offset;
9272 if (gsym != NULL)
9274 gold_assert(gsym->has_got_offset(got_type));
9275 got_offset = gsym->got_offset(got_type) - target->got_size();
9277 else
9279 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9280 gold_assert(object->local_has_got_offset(r_sym, got_type));
9281 got_offset = (object->local_got_offset(r_sym, got_type)
9282 - target->got_size());
9284 if (optimized_type == tls::TLSOPT_NONE)
9286 Arm_address got_entry =
9287 target->got_plt_section()->address() + got_offset;
9289 // Relocate the field with the PC relative offset of the pair of
9290 // GOT entries.
9291 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9292 return ArmRelocFuncs::STATUS_OKAY;
9295 break;
9297 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9298 if (optimized_type == tls::TLSOPT_NONE)
9300 // Relocate the field with the offset of the GOT entry for
9301 // the module index.
9302 unsigned int got_offset;
9303 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9304 - target->got_size());
9305 Arm_address got_entry =
9306 target->got_plt_section()->address() + got_offset;
9308 // Relocate the field with the PC relative offset of the pair of
9309 // GOT entries.
9310 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9311 return ArmRelocFuncs::STATUS_OKAY;
9313 break;
9315 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9316 RelocFuncs::rel32_unaligned(view, value);
9317 return ArmRelocFuncs::STATUS_OKAY;
9319 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9320 if (optimized_type == tls::TLSOPT_NONE)
9322 // Relocate the field with the offset of the GOT entry for
9323 // the tp-relative offset of the symbol.
9324 unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9325 unsigned int got_offset;
9326 if (gsym != NULL)
9328 gold_assert(gsym->has_got_offset(got_type));
9329 got_offset = gsym->got_offset(got_type);
9331 else
9333 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9334 gold_assert(object->local_has_got_offset(r_sym, got_type));
9335 got_offset = object->local_got_offset(r_sym, got_type);
9338 // All GOT offsets are relative to the end of the GOT.
9339 got_offset -= target->got_size();
9341 Arm_address got_entry =
9342 target->got_plt_section()->address() + got_offset;
9344 // Relocate the field with the PC relative offset of the GOT entry.
9345 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9346 return ArmRelocFuncs::STATUS_OKAY;
9348 break;
9350 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9351 // If we're creating a shared library, a dynamic relocation will
9352 // have been created for this location, so do not apply it now.
9353 if (!parameters->options().shared())
9355 gold_assert(tls_segment != NULL);
9357 // $tp points to the TCB, which is followed by the TLS, so we
9358 // need to add TCB size to the offset.
9359 Arm_address aligned_tcb_size =
9360 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9361 RelocFuncs::rel32_unaligned(view, value + aligned_tcb_size);
9364 return ArmRelocFuncs::STATUS_OKAY;
9366 default:
9367 gold_unreachable();
9370 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9371 _("unsupported reloc %u"),
9372 r_type);
9373 return ArmRelocFuncs::STATUS_BAD_RELOC;
9376 // Relocate section data.
9378 template<bool big_endian>
9379 void
9380 Target_arm<big_endian>::relocate_section(
9381 const Relocate_info<32, big_endian>* relinfo,
9382 unsigned int sh_type,
9383 const unsigned char* prelocs,
9384 size_t reloc_count,
9385 Output_section* output_section,
9386 bool needs_special_offset_handling,
9387 unsigned char* view,
9388 Arm_address address,
9389 section_size_type view_size,
9390 const Reloc_symbol_changes* reloc_symbol_changes)
9392 typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
9393 gold_assert(sh_type == elfcpp::SHT_REL);
9395 // See if we are relocating a relaxed input section. If so, the view
9396 // covers the whole output section and we need to adjust accordingly.
9397 if (needs_special_offset_handling)
9399 const Output_relaxed_input_section* poris =
9400 output_section->find_relaxed_input_section(relinfo->object,
9401 relinfo->data_shndx);
9402 if (poris != NULL)
9404 Arm_address section_address = poris->address();
9405 section_size_type section_size = poris->data_size();
9407 gold_assert((section_address >= address)
9408 && ((section_address + section_size)
9409 <= (address + view_size)));
9411 off_t offset = section_address - address;
9412 view += offset;
9413 address += offset;
9414 view_size = section_size;
9418 gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
9419 Arm_relocate>(
9420 relinfo,
9421 this,
9422 prelocs,
9423 reloc_count,
9424 output_section,
9425 needs_special_offset_handling,
9426 view,
9427 address,
9428 view_size,
9429 reloc_symbol_changes);
9432 // Return the size of a relocation while scanning during a relocatable
9433 // link.
9435 template<bool big_endian>
9436 unsigned int
9437 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
9438 unsigned int r_type,
9439 Relobj* object)
9441 r_type = get_real_reloc_type(r_type);
9442 const Arm_reloc_property* arp =
9443 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9444 if (arp != NULL)
9445 return arp->size();
9446 else
9448 std::string reloc_name =
9449 arm_reloc_property_table->reloc_name_in_error_message(r_type);
9450 gold_error(_("%s: unexpected %s in object file"),
9451 object->name().c_str(), reloc_name.c_str());
9452 return 0;
9456 // Scan the relocs during a relocatable link.
9458 template<bool big_endian>
9459 void
9460 Target_arm<big_endian>::scan_relocatable_relocs(
9461 Symbol_table* symtab,
9462 Layout* layout,
9463 Sized_relobj_file<32, big_endian>* object,
9464 unsigned int data_shndx,
9465 unsigned int sh_type,
9466 const unsigned char* prelocs,
9467 size_t reloc_count,
9468 Output_section* output_section,
9469 bool needs_special_offset_handling,
9470 size_t local_symbol_count,
9471 const unsigned char* plocal_symbols,
9472 Relocatable_relocs* rr)
9474 gold_assert(sh_type == elfcpp::SHT_REL);
9476 typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
9477 Relocatable_size_for_reloc> Scan_relocatable_relocs;
9479 gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
9480 Scan_relocatable_relocs>(
9481 symtab,
9482 layout,
9483 object,
9484 data_shndx,
9485 prelocs,
9486 reloc_count,
9487 output_section,
9488 needs_special_offset_handling,
9489 local_symbol_count,
9490 plocal_symbols,
9491 rr);
9494 // Relocate a section during a relocatable link.
9496 template<bool big_endian>
9497 void
9498 Target_arm<big_endian>::relocate_for_relocatable(
9499 const Relocate_info<32, big_endian>* relinfo,
9500 unsigned int sh_type,
9501 const unsigned char* prelocs,
9502 size_t reloc_count,
9503 Output_section* output_section,
9504 off_t offset_in_output_section,
9505 const Relocatable_relocs* rr,
9506 unsigned char* view,
9507 Arm_address view_address,
9508 section_size_type view_size,
9509 unsigned char* reloc_view,
9510 section_size_type reloc_view_size)
9512 gold_assert(sh_type == elfcpp::SHT_REL);
9514 gold::relocate_for_relocatable<32, big_endian, elfcpp::SHT_REL>(
9515 relinfo,
9516 prelocs,
9517 reloc_count,
9518 output_section,
9519 offset_in_output_section,
9521 view,
9522 view_address,
9523 view_size,
9524 reloc_view,
9525 reloc_view_size);
9528 // Perform target-specific processing in a relocatable link. This is
9529 // only used if we use the relocation strategy RELOC_SPECIAL.
9531 template<bool big_endian>
9532 void
9533 Target_arm<big_endian>::relocate_special_relocatable(
9534 const Relocate_info<32, big_endian>* relinfo,
9535 unsigned int sh_type,
9536 const unsigned char* preloc_in,
9537 size_t relnum,
9538 Output_section* output_section,
9539 off_t offset_in_output_section,
9540 unsigned char* view,
9541 elfcpp::Elf_types<32>::Elf_Addr view_address,
9542 section_size_type,
9543 unsigned char* preloc_out)
9545 // We can only handle REL type relocation sections.
9546 gold_assert(sh_type == elfcpp::SHT_REL);
9548 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
9549 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
9550 Reltype_write;
9551 const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
9553 const Arm_relobj<big_endian>* object =
9554 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9555 const unsigned int local_count = object->local_symbol_count();
9557 Reltype reloc(preloc_in);
9558 Reltype_write reloc_write(preloc_out);
9560 elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
9561 const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9562 const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
9564 const Arm_reloc_property* arp =
9565 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9566 gold_assert(arp != NULL);
9568 // Get the new symbol index.
9569 // We only use RELOC_SPECIAL strategy in local relocations.
9570 gold_assert(r_sym < local_count);
9572 // We are adjusting a section symbol. We need to find
9573 // the symbol table index of the section symbol for
9574 // the output section corresponding to input section
9575 // in which this symbol is defined.
9576 bool is_ordinary;
9577 unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
9578 gold_assert(is_ordinary);
9579 Output_section* os = object->output_section(shndx);
9580 gold_assert(os != NULL);
9581 gold_assert(os->needs_symtab_index());
9582 unsigned int new_symndx = os->symtab_index();
9584 // Get the new offset--the location in the output section where
9585 // this relocation should be applied.
9587 Arm_address offset = reloc.get_r_offset();
9588 Arm_address new_offset;
9589 if (offset_in_output_section != invalid_address)
9590 new_offset = offset + offset_in_output_section;
9591 else
9593 section_offset_type sot_offset =
9594 convert_types<section_offset_type, Arm_address>(offset);
9595 section_offset_type new_sot_offset =
9596 output_section->output_offset(object, relinfo->data_shndx,
9597 sot_offset);
9598 gold_assert(new_sot_offset != -1);
9599 new_offset = new_sot_offset;
9602 // In an object file, r_offset is an offset within the section.
9603 // In an executable or dynamic object, generated by
9604 // --emit-relocs, r_offset is an absolute address.
9605 if (!parameters->options().relocatable())
9607 new_offset += view_address;
9608 if (offset_in_output_section != invalid_address)
9609 new_offset -= offset_in_output_section;
9612 reloc_write.put_r_offset(new_offset);
9613 reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
9615 // Handle the reloc addend.
9616 // The relocation uses a section symbol in the input file.
9617 // We are adjusting it to use a section symbol in the output
9618 // file. The input section symbol refers to some address in
9619 // the input section. We need the relocation in the output
9620 // file to refer to that same address. This adjustment to
9621 // the addend is the same calculation we use for a simple
9622 // absolute relocation for the input section symbol.
9624 const Symbol_value<32>* psymval = object->local_symbol(r_sym);
9626 // Handle THUMB bit.
9627 Symbol_value<32> symval;
9628 Arm_address thumb_bit =
9629 object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9630 if (thumb_bit != 0
9631 && arp->uses_thumb_bit()
9632 && ((psymval->value(object, 0) & 1) != 0))
9634 Arm_address stripped_value =
9635 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9636 symval.set_output_value(stripped_value);
9637 psymval = &symval;
9640 unsigned char* paddend = view + offset;
9641 typename Arm_relocate_functions<big_endian>::Status reloc_status =
9642 Arm_relocate_functions<big_endian>::STATUS_OKAY;
9643 switch (r_type)
9645 case elfcpp::R_ARM_ABS8:
9646 reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
9647 psymval);
9648 break;
9650 case elfcpp::R_ARM_ABS12:
9651 reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
9652 psymval);
9653 break;
9655 case elfcpp::R_ARM_ABS16:
9656 reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
9657 psymval);
9658 break;
9660 case elfcpp::R_ARM_THM_ABS5:
9661 reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
9662 object,
9663 psymval);
9664 break;
9666 case elfcpp::R_ARM_MOVW_ABS_NC:
9667 case elfcpp::R_ARM_MOVW_PREL_NC:
9668 case elfcpp::R_ARM_MOVW_BREL_NC:
9669 case elfcpp::R_ARM_MOVW_BREL:
9670 reloc_status = Arm_relocate_functions<big_endian>::movw(
9671 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9672 break;
9674 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9675 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9676 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9677 case elfcpp::R_ARM_THM_MOVW_BREL:
9678 reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
9679 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9680 break;
9682 case elfcpp::R_ARM_THM_CALL:
9683 case elfcpp::R_ARM_THM_XPC22:
9684 case elfcpp::R_ARM_THM_JUMP24:
9685 reloc_status =
9686 Arm_relocate_functions<big_endian>::thumb_branch_common(
9687 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9688 false);
9689 break;
9691 case elfcpp::R_ARM_PLT32:
9692 case elfcpp::R_ARM_CALL:
9693 case elfcpp::R_ARM_JUMP24:
9694 case elfcpp::R_ARM_XPC25:
9695 reloc_status =
9696 Arm_relocate_functions<big_endian>::arm_branch_common(
9697 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9698 false);
9699 break;
9701 case elfcpp::R_ARM_THM_JUMP19:
9702 reloc_status =
9703 Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
9704 psymval, 0, thumb_bit);
9705 break;
9707 case elfcpp::R_ARM_THM_JUMP6:
9708 reloc_status =
9709 Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
9711 break;
9713 case elfcpp::R_ARM_THM_JUMP8:
9714 reloc_status =
9715 Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
9717 break;
9719 case elfcpp::R_ARM_THM_JUMP11:
9720 reloc_status =
9721 Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
9723 break;
9725 case elfcpp::R_ARM_PREL31:
9726 reloc_status =
9727 Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
9728 thumb_bit);
9729 break;
9731 case elfcpp::R_ARM_THM_PC8:
9732 reloc_status =
9733 Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
9735 break;
9737 case elfcpp::R_ARM_THM_PC12:
9738 reloc_status =
9739 Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
9741 break;
9743 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9744 reloc_status =
9745 Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
9746 0, thumb_bit);
9747 break;
9749 // These relocation truncate relocation results so we cannot handle them
9750 // in a relocatable link.
9751 case elfcpp::R_ARM_MOVT_ABS:
9752 case elfcpp::R_ARM_THM_MOVT_ABS:
9753 case elfcpp::R_ARM_MOVT_PREL:
9754 case elfcpp::R_ARM_MOVT_BREL:
9755 case elfcpp::R_ARM_THM_MOVT_PREL:
9756 case elfcpp::R_ARM_THM_MOVT_BREL:
9757 case elfcpp::R_ARM_ALU_PC_G0_NC:
9758 case elfcpp::R_ARM_ALU_PC_G0:
9759 case elfcpp::R_ARM_ALU_PC_G1_NC:
9760 case elfcpp::R_ARM_ALU_PC_G1:
9761 case elfcpp::R_ARM_ALU_PC_G2:
9762 case elfcpp::R_ARM_ALU_SB_G0_NC:
9763 case elfcpp::R_ARM_ALU_SB_G0:
9764 case elfcpp::R_ARM_ALU_SB_G1_NC:
9765 case elfcpp::R_ARM_ALU_SB_G1:
9766 case elfcpp::R_ARM_ALU_SB_G2:
9767 case elfcpp::R_ARM_LDR_PC_G0:
9768 case elfcpp::R_ARM_LDR_PC_G1:
9769 case elfcpp::R_ARM_LDR_PC_G2:
9770 case elfcpp::R_ARM_LDR_SB_G0:
9771 case elfcpp::R_ARM_LDR_SB_G1:
9772 case elfcpp::R_ARM_LDR_SB_G2:
9773 case elfcpp::R_ARM_LDRS_PC_G0:
9774 case elfcpp::R_ARM_LDRS_PC_G1:
9775 case elfcpp::R_ARM_LDRS_PC_G2:
9776 case elfcpp::R_ARM_LDRS_SB_G0:
9777 case elfcpp::R_ARM_LDRS_SB_G1:
9778 case elfcpp::R_ARM_LDRS_SB_G2:
9779 case elfcpp::R_ARM_LDC_PC_G0:
9780 case elfcpp::R_ARM_LDC_PC_G1:
9781 case elfcpp::R_ARM_LDC_PC_G2:
9782 case elfcpp::R_ARM_LDC_SB_G0:
9783 case elfcpp::R_ARM_LDC_SB_G1:
9784 case elfcpp::R_ARM_LDC_SB_G2:
9785 gold_error(_("cannot handle %s in a relocatable link"),
9786 arp->name().c_str());
9787 break;
9789 default:
9790 gold_unreachable();
9793 // Report any errors.
9794 switch (reloc_status)
9796 case Arm_relocate_functions<big_endian>::STATUS_OKAY:
9797 break;
9798 case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
9799 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9800 _("relocation overflow in %s"),
9801 arp->name().c_str());
9802 break;
9803 case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
9804 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9805 _("unexpected opcode while processing relocation %s"),
9806 arp->name().c_str());
9807 break;
9808 default:
9809 gold_unreachable();
9813 // Return the value to use for a dynamic symbol which requires special
9814 // treatment. This is how we support equality comparisons of function
9815 // pointers across shared library boundaries, as described in the
9816 // processor specific ABI supplement.
9818 template<bool big_endian>
9819 uint64_t
9820 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
9822 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
9823 return this->plt_section()->address() + gsym->plt_offset();
9826 // Map platform-specific relocs to real relocs
9828 template<bool big_endian>
9829 unsigned int
9830 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
9832 switch (r_type)
9834 case elfcpp::R_ARM_TARGET1:
9835 // This is either R_ARM_ABS32 or R_ARM_REL32;
9836 return elfcpp::R_ARM_ABS32;
9838 case elfcpp::R_ARM_TARGET2:
9839 // This can be any reloc type but usually is R_ARM_GOT_PREL
9840 return elfcpp::R_ARM_GOT_PREL;
9842 default:
9843 return r_type;
9847 // Whether if two EABI versions V1 and V2 are compatible.
9849 template<bool big_endian>
9850 bool
9851 Target_arm<big_endian>::are_eabi_versions_compatible(
9852 elfcpp::Elf_Word v1,
9853 elfcpp::Elf_Word v2)
9855 // v4 and v5 are the same spec before and after it was released,
9856 // so allow mixing them.
9857 if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
9858 || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
9859 || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
9860 return true;
9862 return v1 == v2;
9865 // Combine FLAGS from an input object called NAME and the processor-specific
9866 // flags in the ELF header of the output. Much of this is adapted from the
9867 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
9868 // in bfd/elf32-arm.c.
9870 template<bool big_endian>
9871 void
9872 Target_arm<big_endian>::merge_processor_specific_flags(
9873 const std::string& name,
9874 elfcpp::Elf_Word flags)
9876 if (this->are_processor_specific_flags_set())
9878 elfcpp::Elf_Word out_flags = this->processor_specific_flags();
9880 // Nothing to merge if flags equal to those in output.
9881 if (flags == out_flags)
9882 return;
9884 // Complain about various flag mismatches.
9885 elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
9886 elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
9887 if (!this->are_eabi_versions_compatible(version1, version2)
9888 && parameters->options().warn_mismatch())
9889 gold_error(_("Source object %s has EABI version %d but output has "
9890 "EABI version %d."),
9891 name.c_str(),
9892 (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
9893 (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
9895 else
9897 // If the input is the default architecture and had the default
9898 // flags then do not bother setting the flags for the output
9899 // architecture, instead allow future merges to do this. If no
9900 // future merges ever set these flags then they will retain their
9901 // uninitialised values, which surprise surprise, correspond
9902 // to the default values.
9903 if (flags == 0)
9904 return;
9906 // This is the first time, just copy the flags.
9907 // We only copy the EABI version for now.
9908 this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
9912 // Adjust ELF file header.
9913 template<bool big_endian>
9914 void
9915 Target_arm<big_endian>::do_adjust_elf_header(
9916 unsigned char* view,
9917 int len) const
9919 gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
9921 elfcpp::Ehdr<32, big_endian> ehdr(view);
9922 unsigned char e_ident[elfcpp::EI_NIDENT];
9923 memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
9925 if (elfcpp::arm_eabi_version(this->processor_specific_flags())
9926 == elfcpp::EF_ARM_EABI_UNKNOWN)
9927 e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
9928 else
9929 e_ident[elfcpp::EI_OSABI] = 0;
9930 e_ident[elfcpp::EI_ABIVERSION] = 0;
9932 // FIXME: Do EF_ARM_BE8 adjustment.
9934 elfcpp::Ehdr_write<32, big_endian> oehdr(view);
9935 oehdr.put_e_ident(e_ident);
9938 // do_make_elf_object to override the same function in the base class.
9939 // We need to use a target-specific sub-class of
9940 // Sized_relobj_file<32, big_endian> to store ARM specific information.
9941 // Hence we need to have our own ELF object creation.
9943 template<bool big_endian>
9944 Object*
9945 Target_arm<big_endian>::do_make_elf_object(
9946 const std::string& name,
9947 Input_file* input_file,
9948 off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
9950 int et = ehdr.get_e_type();
9951 // ET_EXEC files are valid input for --just-symbols/-R,
9952 // and we treat them as relocatable objects.
9953 if (et == elfcpp::ET_REL
9954 || (et == elfcpp::ET_EXEC && input_file->just_symbols()))
9956 Arm_relobj<big_endian>* obj =
9957 new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
9958 obj->setup();
9959 return obj;
9961 else if (et == elfcpp::ET_DYN)
9963 Sized_dynobj<32, big_endian>* obj =
9964 new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
9965 obj->setup();
9966 return obj;
9968 else
9970 gold_error(_("%s: unsupported ELF file type %d"),
9971 name.c_str(), et);
9972 return NULL;
9976 // Read the architecture from the Tag_also_compatible_with attribute, if any.
9977 // Returns -1 if no architecture could be read.
9978 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
9980 template<bool big_endian>
9982 Target_arm<big_endian>::get_secondary_compatible_arch(
9983 const Attributes_section_data* pasd)
9985 const Object_attribute* known_attributes =
9986 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
9988 // Note: the tag and its argument below are uleb128 values, though
9989 // currently-defined values fit in one byte for each.
9990 const std::string& sv =
9991 known_attributes[elfcpp::Tag_also_compatible_with].string_value();
9992 if (sv.size() == 2
9993 && sv.data()[0] == elfcpp::Tag_CPU_arch
9994 && (sv.data()[1] & 128) != 128)
9995 return sv.data()[1];
9997 // This tag is "safely ignorable", so don't complain if it looks funny.
9998 return -1;
10001 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10002 // The tag is removed if ARCH is -1.
10003 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10005 template<bool big_endian>
10006 void
10007 Target_arm<big_endian>::set_secondary_compatible_arch(
10008 Attributes_section_data* pasd,
10009 int arch)
10011 Object_attribute* known_attributes =
10012 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10014 if (arch == -1)
10016 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10017 return;
10020 // Note: the tag and its argument below are uleb128 values, though
10021 // currently-defined values fit in one byte for each.
10022 char sv[3];
10023 sv[0] = elfcpp::Tag_CPU_arch;
10024 gold_assert(arch != 0);
10025 sv[1] = arch;
10026 sv[2] = '\0';
10028 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10031 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10032 // into account.
10033 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10035 template<bool big_endian>
10037 Target_arm<big_endian>::tag_cpu_arch_combine(
10038 const char* name,
10039 int oldtag,
10040 int* secondary_compat_out,
10041 int newtag,
10042 int secondary_compat)
10044 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10045 static const int v6t2[] =
10047 T(V6T2), // PRE_V4.
10048 T(V6T2), // V4.
10049 T(V6T2), // V4T.
10050 T(V6T2), // V5T.
10051 T(V6T2), // V5TE.
10052 T(V6T2), // V5TEJ.
10053 T(V6T2), // V6.
10054 T(V7), // V6KZ.
10055 T(V6T2) // V6T2.
10057 static const int v6k[] =
10059 T(V6K), // PRE_V4.
10060 T(V6K), // V4.
10061 T(V6K), // V4T.
10062 T(V6K), // V5T.
10063 T(V6K), // V5TE.
10064 T(V6K), // V5TEJ.
10065 T(V6K), // V6.
10066 T(V6KZ), // V6KZ.
10067 T(V7), // V6T2.
10068 T(V6K) // V6K.
10070 static const int v7[] =
10072 T(V7), // PRE_V4.
10073 T(V7), // V4.
10074 T(V7), // V4T.
10075 T(V7), // V5T.
10076 T(V7), // V5TE.
10077 T(V7), // V5TEJ.
10078 T(V7), // V6.
10079 T(V7), // V6KZ.
10080 T(V7), // V6T2.
10081 T(V7), // V6K.
10082 T(V7) // V7.
10084 static const int v6_m[] =
10086 -1, // PRE_V4.
10087 -1, // V4.
10088 T(V6K), // V4T.
10089 T(V6K), // V5T.
10090 T(V6K), // V5TE.
10091 T(V6K), // V5TEJ.
10092 T(V6K), // V6.
10093 T(V6KZ), // V6KZ.
10094 T(V7), // V6T2.
10095 T(V6K), // V6K.
10096 T(V7), // V7.
10097 T(V6_M) // V6_M.
10099 static const int v6s_m[] =
10101 -1, // PRE_V4.
10102 -1, // V4.
10103 T(V6K), // V4T.
10104 T(V6K), // V5T.
10105 T(V6K), // V5TE.
10106 T(V6K), // V5TEJ.
10107 T(V6K), // V6.
10108 T(V6KZ), // V6KZ.
10109 T(V7), // V6T2.
10110 T(V6K), // V6K.
10111 T(V7), // V7.
10112 T(V6S_M), // V6_M.
10113 T(V6S_M) // V6S_M.
10115 static const int v7e_m[] =
10117 -1, // PRE_V4.
10118 -1, // V4.
10119 T(V7E_M), // V4T.
10120 T(V7E_M), // V5T.
10121 T(V7E_M), // V5TE.
10122 T(V7E_M), // V5TEJ.
10123 T(V7E_M), // V6.
10124 T(V7E_M), // V6KZ.
10125 T(V7E_M), // V6T2.
10126 T(V7E_M), // V6K.
10127 T(V7E_M), // V7.
10128 T(V7E_M), // V6_M.
10129 T(V7E_M), // V6S_M.
10130 T(V7E_M) // V7E_M.
10132 static const int v4t_plus_v6_m[] =
10134 -1, // PRE_V4.
10135 -1, // V4.
10136 T(V4T), // V4T.
10137 T(V5T), // V5T.
10138 T(V5TE), // V5TE.
10139 T(V5TEJ), // V5TEJ.
10140 T(V6), // V6.
10141 T(V6KZ), // V6KZ.
10142 T(V6T2), // V6T2.
10143 T(V6K), // V6K.
10144 T(V7), // V7.
10145 T(V6_M), // V6_M.
10146 T(V6S_M), // V6S_M.
10147 T(V7E_M), // V7E_M.
10148 T(V4T_PLUS_V6_M) // V4T plus V6_M.
10150 static const int* comb[] =
10152 v6t2,
10153 v6k,
10155 v6_m,
10156 v6s_m,
10157 v7e_m,
10158 // Pseudo-architecture.
10159 v4t_plus_v6_m
10162 // Check we've not got a higher architecture than we know about.
10164 if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
10166 gold_error(_("%s: unknown CPU architecture"), name);
10167 return -1;
10170 // Override old tag if we have a Tag_also_compatible_with on the output.
10172 if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10173 || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10174 oldtag = T(V4T_PLUS_V6_M);
10176 // And override the new tag if we have a Tag_also_compatible_with on the
10177 // input.
10179 if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10180 || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10181 newtag = T(V4T_PLUS_V6_M);
10183 // Architectures before V6KZ add features monotonically.
10184 int tagh = std::max(oldtag, newtag);
10185 if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10186 return tagh;
10188 int tagl = std::min(oldtag, newtag);
10189 int result = comb[tagh - T(V6T2)][tagl];
10191 // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10192 // as the canonical version.
10193 if (result == T(V4T_PLUS_V6_M))
10195 result = T(V4T);
10196 *secondary_compat_out = T(V6_M);
10198 else
10199 *secondary_compat_out = -1;
10201 if (result == -1)
10203 gold_error(_("%s: conflicting CPU architectures %d/%d"),
10204 name, oldtag, newtag);
10205 return -1;
10208 return result;
10209 #undef T
10212 // Helper to print AEABI enum tag value.
10214 template<bool big_endian>
10215 std::string
10216 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10218 static const char* aeabi_enum_names[] =
10219 { "", "variable-size", "32-bit", "" };
10220 const size_t aeabi_enum_names_size =
10221 sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10223 if (value < aeabi_enum_names_size)
10224 return std::string(aeabi_enum_names[value]);
10225 else
10227 char buffer[100];
10228 sprintf(buffer, "<unknown value %u>", value);
10229 return std::string(buffer);
10233 // Return the string value to store in TAG_CPU_name.
10235 template<bool big_endian>
10236 std::string
10237 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10239 static const char* name_table[] = {
10240 // These aren't real CPU names, but we can't guess
10241 // that from the architecture version alone.
10242 "Pre v4",
10243 "ARM v4",
10244 "ARM v4T",
10245 "ARM v5T",
10246 "ARM v5TE",
10247 "ARM v5TEJ",
10248 "ARM v6",
10249 "ARM v6KZ",
10250 "ARM v6T2",
10251 "ARM v6K",
10252 "ARM v7",
10253 "ARM v6-M",
10254 "ARM v6S-M",
10255 "ARM v7E-M"
10257 const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10259 if (value < name_table_size)
10260 return std::string(name_table[value]);
10261 else
10263 char buffer[100];
10264 sprintf(buffer, "<unknown CPU value %u>", value);
10265 return std::string(buffer);
10269 // Merge object attributes from input file called NAME with those of the
10270 // output. The input object attributes are in the object pointed by PASD.
10272 template<bool big_endian>
10273 void
10274 Target_arm<big_endian>::merge_object_attributes(
10275 const char* name,
10276 const Attributes_section_data* pasd)
10278 // Return if there is no attributes section data.
10279 if (pasd == NULL)
10280 return;
10282 // If output has no object attributes, just copy.
10283 const int vendor = Object_attribute::OBJ_ATTR_PROC;
10284 if (this->attributes_section_data_ == NULL)
10286 this->attributes_section_data_ = new Attributes_section_data(*pasd);
10287 Object_attribute* out_attr =
10288 this->attributes_section_data_->known_attributes(vendor);
10290 // We do not output objects with Tag_MPextension_use_legacy - we move
10291 // the attribute's value to Tag_MPextension_use. */
10292 if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10294 if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10295 && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10296 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10298 gold_error(_("%s has both the current and legacy "
10299 "Tag_MPextension_use attributes"),
10300 name);
10303 out_attr[elfcpp::Tag_MPextension_use] =
10304 out_attr[elfcpp::Tag_MPextension_use_legacy];
10305 out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10306 out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10309 return;
10312 const Object_attribute* in_attr = pasd->known_attributes(vendor);
10313 Object_attribute* out_attr =
10314 this->attributes_section_data_->known_attributes(vendor);
10316 // This needs to happen before Tag_ABI_FP_number_model is merged. */
10317 if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10318 != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
10320 // Ignore mismatches if the object doesn't use floating point. */
10321 if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
10322 out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10323 in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10324 else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
10325 && parameters->options().warn_mismatch())
10326 gold_error(_("%s uses VFP register arguments, output does not"),
10327 name);
10330 for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10332 // Merge this attribute with existing attributes.
10333 switch (i)
10335 case elfcpp::Tag_CPU_raw_name:
10336 case elfcpp::Tag_CPU_name:
10337 // These are merged after Tag_CPU_arch.
10338 break;
10340 case elfcpp::Tag_ABI_optimization_goals:
10341 case elfcpp::Tag_ABI_FP_optimization_goals:
10342 // Use the first value seen.
10343 break;
10345 case elfcpp::Tag_CPU_arch:
10347 unsigned int saved_out_attr = out_attr->int_value();
10348 // Merge Tag_CPU_arch and Tag_also_compatible_with.
10349 int secondary_compat =
10350 this->get_secondary_compatible_arch(pasd);
10351 int secondary_compat_out =
10352 this->get_secondary_compatible_arch(
10353 this->attributes_section_data_);
10354 out_attr[i].set_int_value(
10355 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10356 &secondary_compat_out,
10357 in_attr[i].int_value(),
10358 secondary_compat));
10359 this->set_secondary_compatible_arch(this->attributes_section_data_,
10360 secondary_compat_out);
10362 // Merge Tag_CPU_name and Tag_CPU_raw_name.
10363 if (out_attr[i].int_value() == saved_out_attr)
10364 ; // Leave the names alone.
10365 else if (out_attr[i].int_value() == in_attr[i].int_value())
10367 // The output architecture has been changed to match the
10368 // input architecture. Use the input names.
10369 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10370 in_attr[elfcpp::Tag_CPU_name].string_value());
10371 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10372 in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10374 else
10376 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10377 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10380 // If we still don't have a value for Tag_CPU_name,
10381 // make one up now. Tag_CPU_raw_name remains blank.
10382 if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10384 const std::string cpu_name =
10385 this->tag_cpu_name_value(out_attr[i].int_value());
10386 // FIXME: If we see an unknown CPU, this will be set
10387 // to "<unknown CPU n>", where n is the attribute value.
10388 // This is different from BFD, which leaves the name alone.
10389 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10392 break;
10394 case elfcpp::Tag_ARM_ISA_use:
10395 case elfcpp::Tag_THUMB_ISA_use:
10396 case elfcpp::Tag_WMMX_arch:
10397 case elfcpp::Tag_Advanced_SIMD_arch:
10398 // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10399 case elfcpp::Tag_ABI_FP_rounding:
10400 case elfcpp::Tag_ABI_FP_exceptions:
10401 case elfcpp::Tag_ABI_FP_user_exceptions:
10402 case elfcpp::Tag_ABI_FP_number_model:
10403 case elfcpp::Tag_VFP_HP_extension:
10404 case elfcpp::Tag_CPU_unaligned_access:
10405 case elfcpp::Tag_T2EE_use:
10406 case elfcpp::Tag_Virtualization_use:
10407 case elfcpp::Tag_MPextension_use:
10408 // Use the largest value specified.
10409 if (in_attr[i].int_value() > out_attr[i].int_value())
10410 out_attr[i].set_int_value(in_attr[i].int_value());
10411 break;
10413 case elfcpp::Tag_ABI_align8_preserved:
10414 case elfcpp::Tag_ABI_PCS_RO_data:
10415 // Use the smallest value specified.
10416 if (in_attr[i].int_value() < out_attr[i].int_value())
10417 out_attr[i].set_int_value(in_attr[i].int_value());
10418 break;
10420 case elfcpp::Tag_ABI_align8_needed:
10421 if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10422 && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10423 || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10424 == 0)))
10426 // This error message should be enabled once all non-conforming
10427 // binaries in the toolchain have had the attributes set
10428 // properly.
10429 // gold_error(_("output 8-byte data alignment conflicts with %s"),
10430 // name);
10432 // Fall through.
10433 case elfcpp::Tag_ABI_FP_denormal:
10434 case elfcpp::Tag_ABI_PCS_GOT_use:
10436 // These tags have 0 = don't care, 1 = strong requirement,
10437 // 2 = weak requirement.
10438 static const int order_021[3] = {0, 2, 1};
10440 // Use the "greatest" from the sequence 0, 2, 1, or the largest
10441 // value if greater than 2 (for future-proofing).
10442 if ((in_attr[i].int_value() > 2
10443 && in_attr[i].int_value() > out_attr[i].int_value())
10444 || (in_attr[i].int_value() <= 2
10445 && out_attr[i].int_value() <= 2
10446 && (order_021[in_attr[i].int_value()]
10447 > order_021[out_attr[i].int_value()])))
10448 out_attr[i].set_int_value(in_attr[i].int_value());
10450 break;
10452 case elfcpp::Tag_CPU_arch_profile:
10453 if (out_attr[i].int_value() != in_attr[i].int_value())
10455 // 0 will merge with anything.
10456 // 'A' and 'S' merge to 'A'.
10457 // 'R' and 'S' merge to 'R'.
10458 // 'M' and 'A|R|S' is an error.
10459 if (out_attr[i].int_value() == 0
10460 || (out_attr[i].int_value() == 'S'
10461 && (in_attr[i].int_value() == 'A'
10462 || in_attr[i].int_value() == 'R')))
10463 out_attr[i].set_int_value(in_attr[i].int_value());
10464 else if (in_attr[i].int_value() == 0
10465 || (in_attr[i].int_value() == 'S'
10466 && (out_attr[i].int_value() == 'A'
10467 || out_attr[i].int_value() == 'R')))
10468 ; // Do nothing.
10469 else if (parameters->options().warn_mismatch())
10471 gold_error
10472 (_("conflicting architecture profiles %c/%c"),
10473 in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10474 out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10477 break;
10478 case elfcpp::Tag_VFP_arch:
10480 static const struct
10482 int ver;
10483 int regs;
10484 } vfp_versions[7] =
10486 {0, 0},
10487 {1, 16},
10488 {2, 16},
10489 {3, 32},
10490 {3, 16},
10491 {4, 32},
10492 {4, 16}
10495 // Values greater than 6 aren't defined, so just pick the
10496 // biggest.
10497 if (in_attr[i].int_value() > 6
10498 && in_attr[i].int_value() > out_attr[i].int_value())
10500 *out_attr = *in_attr;
10501 break;
10503 // The output uses the superset of input features
10504 // (ISA version) and registers.
10505 int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10506 vfp_versions[out_attr[i].int_value()].ver);
10507 int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10508 vfp_versions[out_attr[i].int_value()].regs);
10509 // This assumes all possible supersets are also a valid
10510 // options.
10511 int newval;
10512 for (newval = 6; newval > 0; newval--)
10514 if (regs == vfp_versions[newval].regs
10515 && ver == vfp_versions[newval].ver)
10516 break;
10518 out_attr[i].set_int_value(newval);
10520 break;
10521 case elfcpp::Tag_PCS_config:
10522 if (out_attr[i].int_value() == 0)
10523 out_attr[i].set_int_value(in_attr[i].int_value());
10524 else if (in_attr[i].int_value() != 0
10525 && out_attr[i].int_value() != 0
10526 && parameters->options().warn_mismatch())
10528 // It's sometimes ok to mix different configs, so this is only
10529 // a warning.
10530 gold_warning(_("%s: conflicting platform configuration"), name);
10532 break;
10533 case elfcpp::Tag_ABI_PCS_R9_use:
10534 if (in_attr[i].int_value() != out_attr[i].int_value()
10535 && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10536 && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10537 && parameters->options().warn_mismatch())
10539 gold_error(_("%s: conflicting use of R9"), name);
10541 if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10542 out_attr[i].set_int_value(in_attr[i].int_value());
10543 break;
10544 case elfcpp::Tag_ABI_PCS_RW_data:
10545 if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10546 && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10547 != elfcpp::AEABI_R9_SB)
10548 && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10549 != elfcpp::AEABI_R9_unused)
10550 && parameters->options().warn_mismatch())
10552 gold_error(_("%s: SB relative addressing conflicts with use "
10553 "of R9"),
10554 name);
10556 // Use the smallest value specified.
10557 if (in_attr[i].int_value() < out_attr[i].int_value())
10558 out_attr[i].set_int_value(in_attr[i].int_value());
10559 break;
10560 case elfcpp::Tag_ABI_PCS_wchar_t:
10561 if (out_attr[i].int_value()
10562 && in_attr[i].int_value()
10563 && out_attr[i].int_value() != in_attr[i].int_value()
10564 && parameters->options().warn_mismatch()
10565 && parameters->options().wchar_size_warning())
10567 gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10568 "use %u-byte wchar_t; use of wchar_t values "
10569 "across objects may fail"),
10570 name, in_attr[i].int_value(),
10571 out_attr[i].int_value());
10573 else if (in_attr[i].int_value() && !out_attr[i].int_value())
10574 out_attr[i].set_int_value(in_attr[i].int_value());
10575 break;
10576 case elfcpp::Tag_ABI_enum_size:
10577 if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10579 if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10580 || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10582 // The existing object is compatible with anything.
10583 // Use whatever requirements the new object has.
10584 out_attr[i].set_int_value(in_attr[i].int_value());
10586 else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10587 && out_attr[i].int_value() != in_attr[i].int_value()
10588 && parameters->options().warn_mismatch()
10589 && parameters->options().enum_size_warning())
10591 unsigned int in_value = in_attr[i].int_value();
10592 unsigned int out_value = out_attr[i].int_value();
10593 gold_warning(_("%s uses %s enums yet the output is to use "
10594 "%s enums; use of enum values across objects "
10595 "may fail"),
10596 name,
10597 this->aeabi_enum_name(in_value).c_str(),
10598 this->aeabi_enum_name(out_value).c_str());
10601 break;
10602 case elfcpp::Tag_ABI_VFP_args:
10603 // Already done.
10604 break;
10605 case elfcpp::Tag_ABI_WMMX_args:
10606 if (in_attr[i].int_value() != out_attr[i].int_value()
10607 && parameters->options().warn_mismatch())
10609 gold_error(_("%s uses iWMMXt register arguments, output does "
10610 "not"),
10611 name);
10613 break;
10614 case Object_attribute::Tag_compatibility:
10615 // Merged in target-independent code.
10616 break;
10617 case elfcpp::Tag_ABI_HardFP_use:
10618 // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10619 if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10620 || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10621 out_attr[i].set_int_value(3);
10622 else if (in_attr[i].int_value() > out_attr[i].int_value())
10623 out_attr[i].set_int_value(in_attr[i].int_value());
10624 break;
10625 case elfcpp::Tag_ABI_FP_16bit_format:
10626 if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10628 if (in_attr[i].int_value() != out_attr[i].int_value()
10629 && parameters->options().warn_mismatch())
10630 gold_error(_("fp16 format mismatch between %s and output"),
10631 name);
10633 if (in_attr[i].int_value() != 0)
10634 out_attr[i].set_int_value(in_attr[i].int_value());
10635 break;
10637 case elfcpp::Tag_DIV_use:
10638 // This tag is set to zero if we can use UDIV and SDIV in Thumb
10639 // mode on a v7-M or v7-R CPU; to one if we can not use UDIV or
10640 // SDIV at all; and to two if we can use UDIV or SDIV on a v7-A
10641 // CPU. We will merge as follows: If the input attribute's value
10642 // is one then the output attribute's value remains unchanged. If
10643 // the input attribute's value is zero or two then if the output
10644 // attribute's value is one the output value is set to the input
10645 // value, otherwise the output value must be the same as the
10646 // inputs. */
10647 if (in_attr[i].int_value() != 1 && out_attr[i].int_value() != 1)
10649 if (in_attr[i].int_value() != out_attr[i].int_value())
10651 gold_error(_("DIV usage mismatch between %s and output"),
10652 name);
10656 if (in_attr[i].int_value() != 1)
10657 out_attr[i].set_int_value(in_attr[i].int_value());
10659 break;
10661 case elfcpp::Tag_MPextension_use_legacy:
10662 // We don't output objects with Tag_MPextension_use_legacy - we
10663 // move the value to Tag_MPextension_use.
10664 if (in_attr[i].int_value() != 0
10665 && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10667 if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10668 != in_attr[i].int_value())
10670 gold_error(_("%s has has both the current and legacy "
10671 "Tag_MPextension_use attributes"),
10672 name);
10676 if (in_attr[i].int_value()
10677 > out_attr[elfcpp::Tag_MPextension_use].int_value())
10678 out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10680 break;
10682 case elfcpp::Tag_nodefaults:
10683 // This tag is set if it exists, but the value is unused (and is
10684 // typically zero). We don't actually need to do anything here -
10685 // the merge happens automatically when the type flags are merged
10686 // below.
10687 break;
10688 case elfcpp::Tag_also_compatible_with:
10689 // Already done in Tag_CPU_arch.
10690 break;
10691 case elfcpp::Tag_conformance:
10692 // Keep the attribute if it matches. Throw it away otherwise.
10693 // No attribute means no claim to conform.
10694 if (in_attr[i].string_value() != out_attr[i].string_value())
10695 out_attr[i].set_string_value("");
10696 break;
10698 default:
10700 const char* err_object = NULL;
10702 // The "known_obj_attributes" table does contain some undefined
10703 // attributes. Ensure that there are unused.
10704 if (out_attr[i].int_value() != 0
10705 || out_attr[i].string_value() != "")
10706 err_object = "output";
10707 else if (in_attr[i].int_value() != 0
10708 || in_attr[i].string_value() != "")
10709 err_object = name;
10711 if (err_object != NULL
10712 && parameters->options().warn_mismatch())
10714 // Attribute numbers >=64 (mod 128) can be safely ignored.
10715 if ((i & 127) < 64)
10716 gold_error(_("%s: unknown mandatory EABI object attribute "
10717 "%d"),
10718 err_object, i);
10719 else
10720 gold_warning(_("%s: unknown EABI object attribute %d"),
10721 err_object, i);
10724 // Only pass on attributes that match in both inputs.
10725 if (!in_attr[i].matches(out_attr[i]))
10727 out_attr[i].set_int_value(0);
10728 out_attr[i].set_string_value("");
10733 // If out_attr was copied from in_attr then it won't have a type yet.
10734 if (in_attr[i].type() && !out_attr[i].type())
10735 out_attr[i].set_type(in_attr[i].type());
10738 // Merge Tag_compatibility attributes and any common GNU ones.
10739 this->attributes_section_data_->merge(name, pasd);
10741 // Check for any attributes not known on ARM.
10742 typedef Vendor_object_attributes::Other_attributes Other_attributes;
10743 const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10744 Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10745 Other_attributes* out_other_attributes =
10746 this->attributes_section_data_->other_attributes(vendor);
10747 Other_attributes::iterator out_iter = out_other_attributes->begin();
10749 while (in_iter != in_other_attributes->end()
10750 || out_iter != out_other_attributes->end())
10752 const char* err_object = NULL;
10753 int err_tag = 0;
10755 // The tags for each list are in numerical order.
10756 // If the tags are equal, then merge.
10757 if (out_iter != out_other_attributes->end()
10758 && (in_iter == in_other_attributes->end()
10759 || in_iter->first > out_iter->first))
10761 // This attribute only exists in output. We can't merge, and we
10762 // don't know what the tag means, so delete it.
10763 err_object = "output";
10764 err_tag = out_iter->first;
10765 int saved_tag = out_iter->first;
10766 delete out_iter->second;
10767 out_other_attributes->erase(out_iter);
10768 out_iter = out_other_attributes->upper_bound(saved_tag);
10770 else if (in_iter != in_other_attributes->end()
10771 && (out_iter != out_other_attributes->end()
10772 || in_iter->first < out_iter->first))
10774 // This attribute only exists in input. We can't merge, and we
10775 // don't know what the tag means, so ignore it.
10776 err_object = name;
10777 err_tag = in_iter->first;
10778 ++in_iter;
10780 else // The tags are equal.
10782 // As present, all attributes in the list are unknown, and
10783 // therefore can't be merged meaningfully.
10784 err_object = "output";
10785 err_tag = out_iter->first;
10787 // Only pass on attributes that match in both inputs.
10788 if (!in_iter->second->matches(*(out_iter->second)))
10790 // No match. Delete the attribute.
10791 int saved_tag = out_iter->first;
10792 delete out_iter->second;
10793 out_other_attributes->erase(out_iter);
10794 out_iter = out_other_attributes->upper_bound(saved_tag);
10796 else
10798 // Matched. Keep the attribute and move to the next.
10799 ++out_iter;
10800 ++in_iter;
10804 if (err_object && parameters->options().warn_mismatch())
10806 // Attribute numbers >=64 (mod 128) can be safely ignored. */
10807 if ((err_tag & 127) < 64)
10809 gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10810 err_object, err_tag);
10812 else
10814 gold_warning(_("%s: unknown EABI object attribute %d"),
10815 err_object, err_tag);
10821 // Stub-generation methods for Target_arm.
10823 // Make a new Arm_input_section object.
10825 template<bool big_endian>
10826 Arm_input_section<big_endian>*
10827 Target_arm<big_endian>::new_arm_input_section(
10828 Relobj* relobj,
10829 unsigned int shndx)
10831 Section_id sid(relobj, shndx);
10833 Arm_input_section<big_endian>* arm_input_section =
10834 new Arm_input_section<big_endian>(relobj, shndx);
10835 arm_input_section->init();
10837 // Register new Arm_input_section in map for look-up.
10838 std::pair<typename Arm_input_section_map::iterator, bool> ins =
10839 this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
10841 // Make sure that it we have not created another Arm_input_section
10842 // for this input section already.
10843 gold_assert(ins.second);
10845 return arm_input_section;
10848 // Find the Arm_input_section object corresponding to the SHNDX-th input
10849 // section of RELOBJ.
10851 template<bool big_endian>
10852 Arm_input_section<big_endian>*
10853 Target_arm<big_endian>::find_arm_input_section(
10854 Relobj* relobj,
10855 unsigned int shndx) const
10857 Section_id sid(relobj, shndx);
10858 typename Arm_input_section_map::const_iterator p =
10859 this->arm_input_section_map_.find(sid);
10860 return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
10863 // Make a new stub table.
10865 template<bool big_endian>
10866 Stub_table<big_endian>*
10867 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
10869 Stub_table<big_endian>* stub_table =
10870 new Stub_table<big_endian>(owner);
10871 this->stub_tables_.push_back(stub_table);
10873 stub_table->set_address(owner->address() + owner->data_size());
10874 stub_table->set_file_offset(owner->offset() + owner->data_size());
10875 stub_table->finalize_data_size();
10877 return stub_table;
10880 // Scan a relocation for stub generation.
10882 template<bool big_endian>
10883 void
10884 Target_arm<big_endian>::scan_reloc_for_stub(
10885 const Relocate_info<32, big_endian>* relinfo,
10886 unsigned int r_type,
10887 const Sized_symbol<32>* gsym,
10888 unsigned int r_sym,
10889 const Symbol_value<32>* psymval,
10890 elfcpp::Elf_types<32>::Elf_Swxword addend,
10891 Arm_address address)
10893 typedef typename Target_arm<big_endian>::Relocate Relocate;
10895 const Arm_relobj<big_endian>* arm_relobj =
10896 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10898 bool target_is_thumb;
10899 Symbol_value<32> symval;
10900 if (gsym != NULL)
10902 // This is a global symbol. Determine if we use PLT and if the
10903 // final target is THUMB.
10904 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
10906 // This uses a PLT, change the symbol value.
10907 symval.set_output_value(this->plt_section()->address()
10908 + gsym->plt_offset());
10909 psymval = &symval;
10910 target_is_thumb = false;
10912 else if (gsym->is_undefined())
10913 // There is no need to generate a stub symbol is undefined.
10914 return;
10915 else
10917 target_is_thumb =
10918 ((gsym->type() == elfcpp::STT_ARM_TFUNC)
10919 || (gsym->type() == elfcpp::STT_FUNC
10920 && !gsym->is_undefined()
10921 && ((psymval->value(arm_relobj, 0) & 1) != 0)));
10924 else
10926 // This is a local symbol. Determine if the final target is THUMB.
10927 target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
10930 // Strip LSB if this points to a THUMB target.
10931 const Arm_reloc_property* reloc_property =
10932 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10933 gold_assert(reloc_property != NULL);
10934 if (target_is_thumb
10935 && reloc_property->uses_thumb_bit()
10936 && ((psymval->value(arm_relobj, 0) & 1) != 0))
10938 Arm_address stripped_value =
10939 psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
10940 symval.set_output_value(stripped_value);
10941 psymval = &symval;
10944 // Get the symbol value.
10945 Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
10947 // Owing to pipelining, the PC relative branches below actually skip
10948 // two instructions when the branch offset is 0.
10949 Arm_address destination;
10950 switch (r_type)
10952 case elfcpp::R_ARM_CALL:
10953 case elfcpp::R_ARM_JUMP24:
10954 case elfcpp::R_ARM_PLT32:
10955 // ARM branches.
10956 destination = value + addend + 8;
10957 break;
10958 case elfcpp::R_ARM_THM_CALL:
10959 case elfcpp::R_ARM_THM_XPC22:
10960 case elfcpp::R_ARM_THM_JUMP24:
10961 case elfcpp::R_ARM_THM_JUMP19:
10962 // THUMB branches.
10963 destination = value + addend + 4;
10964 break;
10965 default:
10966 gold_unreachable();
10969 Reloc_stub* stub = NULL;
10970 Stub_type stub_type =
10971 Reloc_stub::stub_type_for_reloc(r_type, address, destination,
10972 target_is_thumb);
10973 if (stub_type != arm_stub_none)
10975 // Try looking up an existing stub from a stub table.
10976 Stub_table<big_endian>* stub_table =
10977 arm_relobj->stub_table(relinfo->data_shndx);
10978 gold_assert(stub_table != NULL);
10980 // Locate stub by destination.
10981 Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
10983 // Create a stub if there is not one already
10984 stub = stub_table->find_reloc_stub(stub_key);
10985 if (stub == NULL)
10987 // create a new stub and add it to stub table.
10988 stub = this->stub_factory().make_reloc_stub(stub_type);
10989 stub_table->add_reloc_stub(stub, stub_key);
10992 // Record the destination address.
10993 stub->set_destination_address(destination
10994 | (target_is_thumb ? 1 : 0));
10997 // For Cortex-A8, we need to record a relocation at 4K page boundary.
10998 if (this->fix_cortex_a8_
10999 && (r_type == elfcpp::R_ARM_THM_JUMP24
11000 || r_type == elfcpp::R_ARM_THM_JUMP19
11001 || r_type == elfcpp::R_ARM_THM_CALL
11002 || r_type == elfcpp::R_ARM_THM_XPC22)
11003 && (address & 0xfffU) == 0xffeU)
11005 // Found a candidate. Note we haven't checked the destination is
11006 // within 4K here: if we do so (and don't create a record) we can't
11007 // tell that a branch should have been relocated when scanning later.
11008 this->cortex_a8_relocs_info_[address] =
11009 new Cortex_a8_reloc(stub, r_type,
11010 destination | (target_is_thumb ? 1 : 0));
11014 // This function scans a relocation sections for stub generation.
11015 // The template parameter Relocate must be a class type which provides
11016 // a single function, relocate(), which implements the machine
11017 // specific part of a relocation.
11019 // BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type:
11020 // SHT_REL or SHT_RELA.
11022 // PRELOCS points to the relocation data. RELOC_COUNT is the number
11023 // of relocs. OUTPUT_SECTION is the output section.
11024 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
11025 // mapped to output offsets.
11027 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
11028 // VIEW_SIZE is the size. These refer to the input section, unless
11029 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
11030 // the output section.
11032 template<bool big_endian>
11033 template<int sh_type>
11034 void inline
11035 Target_arm<big_endian>::scan_reloc_section_for_stubs(
11036 const Relocate_info<32, big_endian>* relinfo,
11037 const unsigned char* prelocs,
11038 size_t reloc_count,
11039 Output_section* output_section,
11040 bool needs_special_offset_handling,
11041 const unsigned char* view,
11042 elfcpp::Elf_types<32>::Elf_Addr view_address,
11043 section_size_type)
11045 typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
11046 const int reloc_size =
11047 Reloc_types<sh_type, 32, big_endian>::reloc_size;
11049 Arm_relobj<big_endian>* arm_object =
11050 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11051 unsigned int local_count = arm_object->local_symbol_count();
11053 Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11055 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11057 Reltype reloc(prelocs);
11059 typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11060 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11061 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11063 r_type = this->get_real_reloc_type(r_type);
11065 // Only a few relocation types need stubs.
11066 if ((r_type != elfcpp::R_ARM_CALL)
11067 && (r_type != elfcpp::R_ARM_JUMP24)
11068 && (r_type != elfcpp::R_ARM_PLT32)
11069 && (r_type != elfcpp::R_ARM_THM_CALL)
11070 && (r_type != elfcpp::R_ARM_THM_XPC22)
11071 && (r_type != elfcpp::R_ARM_THM_JUMP24)
11072 && (r_type != elfcpp::R_ARM_THM_JUMP19)
11073 && (r_type != elfcpp::R_ARM_V4BX))
11074 continue;
11076 section_offset_type offset =
11077 convert_to_section_size_type(reloc.get_r_offset());
11079 if (needs_special_offset_handling)
11081 offset = output_section->output_offset(relinfo->object,
11082 relinfo->data_shndx,
11083 offset);
11084 if (offset == -1)
11085 continue;
11088 // Create a v4bx stub if --fix-v4bx-interworking is used.
11089 if (r_type == elfcpp::R_ARM_V4BX)
11091 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11093 // Get the BX instruction.
11094 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11095 const Valtype* wv =
11096 reinterpret_cast<const Valtype*>(view + offset);
11097 elfcpp::Elf_types<32>::Elf_Swxword insn =
11098 elfcpp::Swap<32, big_endian>::readval(wv);
11099 const uint32_t reg = (insn & 0xf);
11101 if (reg < 0xf)
11103 // Try looking up an existing stub from a stub table.
11104 Stub_table<big_endian>* stub_table =
11105 arm_object->stub_table(relinfo->data_shndx);
11106 gold_assert(stub_table != NULL);
11108 if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11110 // create a new stub and add it to stub table.
11111 Arm_v4bx_stub* stub =
11112 this->stub_factory().make_arm_v4bx_stub(reg);
11113 gold_assert(stub != NULL);
11114 stub_table->add_arm_v4bx_stub(stub);
11118 continue;
11121 // Get the addend.
11122 Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11123 elfcpp::Elf_types<32>::Elf_Swxword addend =
11124 stub_addend_reader(r_type, view + offset, reloc);
11126 const Sized_symbol<32>* sym;
11128 Symbol_value<32> symval;
11129 const Symbol_value<32> *psymval;
11130 bool is_defined_in_discarded_section;
11131 unsigned int shndx;
11132 if (r_sym < local_count)
11134 sym = NULL;
11135 psymval = arm_object->local_symbol(r_sym);
11137 // If the local symbol belongs to a section we are discarding,
11138 // and that section is a debug section, try to find the
11139 // corresponding kept section and map this symbol to its
11140 // counterpart in the kept section. The symbol must not
11141 // correspond to a section we are folding.
11142 bool is_ordinary;
11143 shndx = psymval->input_shndx(&is_ordinary);
11144 is_defined_in_discarded_section =
11145 (is_ordinary
11146 && shndx != elfcpp::SHN_UNDEF
11147 && !arm_object->is_section_included(shndx)
11148 && !relinfo->symtab->is_section_folded(arm_object, shndx));
11150 // We need to compute the would-be final value of this local
11151 // symbol.
11152 if (!is_defined_in_discarded_section)
11154 typedef Sized_relobj_file<32, big_endian> ObjType;
11155 typename ObjType::Compute_final_local_value_status status =
11156 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11157 relinfo->symtab);
11158 if (status == ObjType::CFLV_OK)
11160 // Currently we cannot handle a branch to a target in
11161 // a merged section. If this is the case, issue an error
11162 // and also free the merge symbol value.
11163 if (!symval.has_output_value())
11165 const std::string& section_name =
11166 arm_object->section_name(shndx);
11167 arm_object->error(_("cannot handle branch to local %u "
11168 "in a merged section %s"),
11169 r_sym, section_name.c_str());
11171 psymval = &symval;
11173 else
11175 // We cannot determine the final value.
11176 continue;
11180 else
11182 const Symbol* gsym;
11183 gsym = arm_object->global_symbol(r_sym);
11184 gold_assert(gsym != NULL);
11185 if (gsym->is_forwarder())
11186 gsym = relinfo->symtab->resolve_forwards(gsym);
11188 sym = static_cast<const Sized_symbol<32>*>(gsym);
11189 if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11190 symval.set_output_symtab_index(sym->symtab_index());
11191 else
11192 symval.set_no_output_symtab_entry();
11194 // We need to compute the would-be final value of this global
11195 // symbol.
11196 const Symbol_table* symtab = relinfo->symtab;
11197 const Sized_symbol<32>* sized_symbol =
11198 symtab->get_sized_symbol<32>(gsym);
11199 Symbol_table::Compute_final_value_status status;
11200 Arm_address value =
11201 symtab->compute_final_value<32>(sized_symbol, &status);
11203 // Skip this if the symbol has not output section.
11204 if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11205 continue;
11206 symval.set_output_value(value);
11208 if (gsym->type() == elfcpp::STT_TLS)
11209 symval.set_is_tls_symbol();
11210 else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11211 symval.set_is_ifunc_symbol();
11212 psymval = &symval;
11214 is_defined_in_discarded_section =
11215 (gsym->is_defined_in_discarded_section()
11216 && gsym->is_undefined());
11217 shndx = 0;
11220 Symbol_value<32> symval2;
11221 if (is_defined_in_discarded_section)
11223 if (comdat_behavior == CB_UNDETERMINED)
11225 std::string name = arm_object->section_name(relinfo->data_shndx);
11226 comdat_behavior = get_comdat_behavior(name.c_str());
11228 if (comdat_behavior == CB_PRETEND)
11230 // FIXME: This case does not work for global symbols.
11231 // We have no place to store the original section index.
11232 // Fortunately this does not matter for comdat sections,
11233 // only for sections explicitly discarded by a linker
11234 // script.
11235 bool found;
11236 typename elfcpp::Elf_types<32>::Elf_Addr value =
11237 arm_object->map_to_kept_section(shndx, &found);
11238 if (found)
11239 symval2.set_output_value(value + psymval->input_value());
11240 else
11241 symval2.set_output_value(0);
11243 else
11245 if (comdat_behavior == CB_WARNING)
11246 gold_warning_at_location(relinfo, i, offset,
11247 _("relocation refers to discarded "
11248 "section"));
11249 symval2.set_output_value(0);
11251 symval2.set_no_output_symtab_entry();
11252 psymval = &symval2;
11255 // If symbol is a section symbol, we don't know the actual type of
11256 // destination. Give up.
11257 if (psymval->is_section_symbol())
11258 continue;
11260 this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11261 addend, view_address + offset);
11265 // Scan an input section for stub generation.
11267 template<bool big_endian>
11268 void
11269 Target_arm<big_endian>::scan_section_for_stubs(
11270 const Relocate_info<32, big_endian>* relinfo,
11271 unsigned int sh_type,
11272 const unsigned char* prelocs,
11273 size_t reloc_count,
11274 Output_section* output_section,
11275 bool needs_special_offset_handling,
11276 const unsigned char* view,
11277 Arm_address view_address,
11278 section_size_type view_size)
11280 if (sh_type == elfcpp::SHT_REL)
11281 this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11282 relinfo,
11283 prelocs,
11284 reloc_count,
11285 output_section,
11286 needs_special_offset_handling,
11287 view,
11288 view_address,
11289 view_size);
11290 else if (sh_type == elfcpp::SHT_RELA)
11291 // We do not support RELA type relocations yet. This is provided for
11292 // completeness.
11293 this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11294 relinfo,
11295 prelocs,
11296 reloc_count,
11297 output_section,
11298 needs_special_offset_handling,
11299 view,
11300 view_address,
11301 view_size);
11302 else
11303 gold_unreachable();
11306 // Group input sections for stub generation.
11308 // We group input sections in an output section so that the total size,
11309 // including any padding space due to alignment is smaller than GROUP_SIZE
11310 // unless the only input section in group is bigger than GROUP_SIZE already.
11311 // Then an ARM stub table is created to follow the last input section
11312 // in group. For each group an ARM stub table is created an is placed
11313 // after the last group. If STUB_ALWAYS_AFTER_BRANCH is false, we further
11314 // extend the group after the stub table.
11316 template<bool big_endian>
11317 void
11318 Target_arm<big_endian>::group_sections(
11319 Layout* layout,
11320 section_size_type group_size,
11321 bool stubs_always_after_branch,
11322 const Task* task)
11324 // Group input sections and insert stub table
11325 Layout::Section_list section_list;
11326 layout->get_allocated_sections(&section_list);
11327 for (Layout::Section_list::const_iterator p = section_list.begin();
11328 p != section_list.end();
11329 ++p)
11331 Arm_output_section<big_endian>* output_section =
11332 Arm_output_section<big_endian>::as_arm_output_section(*p);
11333 output_section->group_sections(group_size, stubs_always_after_branch,
11334 this, task);
11338 // Relaxation hook. This is where we do stub generation.
11340 template<bool big_endian>
11341 bool
11342 Target_arm<big_endian>::do_relax(
11343 int pass,
11344 const Input_objects* input_objects,
11345 Symbol_table* symtab,
11346 Layout* layout,
11347 const Task* task)
11349 // No need to generate stubs if this is a relocatable link.
11350 gold_assert(!parameters->options().relocatable());
11352 // If this is the first pass, we need to group input sections into
11353 // stub groups.
11354 bool done_exidx_fixup = false;
11355 typedef typename Stub_table_list::iterator Stub_table_iterator;
11356 if (pass == 1)
11358 // Determine the stub group size. The group size is the absolute
11359 // value of the parameter --stub-group-size. If --stub-group-size
11360 // is passed a negative value, we restrict stubs to be always after
11361 // the stubbed branches.
11362 int32_t stub_group_size_param =
11363 parameters->options().stub_group_size();
11364 bool stubs_always_after_branch = stub_group_size_param < 0;
11365 section_size_type stub_group_size = abs(stub_group_size_param);
11367 if (stub_group_size == 1)
11369 // Default value.
11370 // Thumb branch range is +-4MB has to be used as the default
11371 // maximum size (a given section can contain both ARM and Thumb
11372 // code, so the worst case has to be taken into account). If we are
11373 // fixing cortex-a8 errata, the branch range has to be even smaller,
11374 // since wide conditional branch has a range of +-1MB only.
11376 // This value is 48K less than that, which allows for 4096
11377 // 12-byte stubs. If we exceed that, then we will fail to link.
11378 // The user will have to relink with an explicit group size
11379 // option.
11380 stub_group_size = 4145152;
11383 // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11384 // page as the first half of a 32-bit branch straddling two 4K pages.
11385 // This is a crude way of enforcing that. In addition, long conditional
11386 // branches of THUMB-2 have a range of +-1M. If we are fixing cortex-A8
11387 // erratum, limit the group size to (1M - 12k) to avoid unreachable
11388 // cortex-A8 stubs from long conditional branches.
11389 if (this->fix_cortex_a8_)
11391 stubs_always_after_branch = true;
11392 const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11393 stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11396 group_sections(layout, stub_group_size, stubs_always_after_branch, task);
11398 // Also fix .ARM.exidx section coverage.
11399 Arm_output_section<big_endian>* exidx_output_section = NULL;
11400 for (Layout::Section_list::const_iterator p =
11401 layout->section_list().begin();
11402 p != layout->section_list().end();
11403 ++p)
11404 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11406 if (exidx_output_section == NULL)
11407 exidx_output_section =
11408 Arm_output_section<big_endian>::as_arm_output_section(*p);
11409 else
11410 // We cannot handle this now.
11411 gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11412 "non-relocatable link"),
11413 exidx_output_section->name(),
11414 (*p)->name());
11417 if (exidx_output_section != NULL)
11419 this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11420 symtab, task);
11421 done_exidx_fixup = true;
11424 else
11426 // If this is not the first pass, addresses and file offsets have
11427 // been reset at this point, set them here.
11428 for (Stub_table_iterator sp = this->stub_tables_.begin();
11429 sp != this->stub_tables_.end();
11430 ++sp)
11432 Arm_input_section<big_endian>* owner = (*sp)->owner();
11433 off_t off = align_address(owner->original_size(),
11434 (*sp)->addralign());
11435 (*sp)->set_address_and_file_offset(owner->address() + off,
11436 owner->offset() + off);
11440 // The Cortex-A8 stubs are sensitive to layout of code sections. At the
11441 // beginning of each relaxation pass, just blow away all the stubs.
11442 // Alternatively, we could selectively remove only the stubs and reloc
11443 // information for code sections that have moved since the last pass.
11444 // That would require more book-keeping.
11445 if (this->fix_cortex_a8_)
11447 // Clear all Cortex-A8 reloc information.
11448 for (typename Cortex_a8_relocs_info::const_iterator p =
11449 this->cortex_a8_relocs_info_.begin();
11450 p != this->cortex_a8_relocs_info_.end();
11451 ++p)
11452 delete p->second;
11453 this->cortex_a8_relocs_info_.clear();
11455 // Remove all Cortex-A8 stubs.
11456 for (Stub_table_iterator sp = this->stub_tables_.begin();
11457 sp != this->stub_tables_.end();
11458 ++sp)
11459 (*sp)->remove_all_cortex_a8_stubs();
11462 // Scan relocs for relocation stubs
11463 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11464 op != input_objects->relobj_end();
11465 ++op)
11467 Arm_relobj<big_endian>* arm_relobj =
11468 Arm_relobj<big_endian>::as_arm_relobj(*op);
11469 // Lock the object so we can read from it. This is only called
11470 // single-threaded from Layout::finalize, so it is OK to lock.
11471 Task_lock_obj<Object> tl(task, arm_relobj);
11472 arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11475 // Check all stub tables to see if any of them have their data sizes
11476 // or addresses alignments changed. These are the only things that
11477 // matter.
11478 bool any_stub_table_changed = false;
11479 Unordered_set<const Output_section*> sections_needing_adjustment;
11480 for (Stub_table_iterator sp = this->stub_tables_.begin();
11481 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11482 ++sp)
11484 if ((*sp)->update_data_size_and_addralign())
11486 // Update data size of stub table owner.
11487 Arm_input_section<big_endian>* owner = (*sp)->owner();
11488 uint64_t address = owner->address();
11489 off_t offset = owner->offset();
11490 owner->reset_address_and_file_offset();
11491 owner->set_address_and_file_offset(address, offset);
11493 sections_needing_adjustment.insert(owner->output_section());
11494 any_stub_table_changed = true;
11498 // Output_section_data::output_section() returns a const pointer but we
11499 // need to update output sections, so we record all output sections needing
11500 // update above and scan the sections here to find out what sections need
11501 // to be updated.
11502 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
11503 p != layout->section_list().end();
11504 ++p)
11506 if (sections_needing_adjustment.find(*p)
11507 != sections_needing_adjustment.end())
11508 (*p)->set_section_offsets_need_adjustment();
11511 // Stop relaxation if no EXIDX fix-up and no stub table change.
11512 bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11514 // Finalize the stubs in the last relaxation pass.
11515 if (!continue_relaxation)
11517 for (Stub_table_iterator sp = this->stub_tables_.begin();
11518 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11519 ++sp)
11520 (*sp)->finalize_stubs();
11522 // Update output local symbol counts of objects if necessary.
11523 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11524 op != input_objects->relobj_end();
11525 ++op)
11527 Arm_relobj<big_endian>* arm_relobj =
11528 Arm_relobj<big_endian>::as_arm_relobj(*op);
11530 // Update output local symbol counts. We need to discard local
11531 // symbols defined in parts of input sections that are discarded by
11532 // relaxation.
11533 if (arm_relobj->output_local_symbol_count_needs_update())
11535 // We need to lock the object's file to update it.
11536 Task_lock_obj<Object> tl(task, arm_relobj);
11537 arm_relobj->update_output_local_symbol_count();
11542 return continue_relaxation;
11545 // Relocate a stub.
11547 template<bool big_endian>
11548 void
11549 Target_arm<big_endian>::relocate_stub(
11550 Stub* stub,
11551 const Relocate_info<32, big_endian>* relinfo,
11552 Output_section* output_section,
11553 unsigned char* view,
11554 Arm_address address,
11555 section_size_type view_size)
11557 Relocate relocate;
11558 const Stub_template* stub_template = stub->stub_template();
11559 for (size_t i = 0; i < stub_template->reloc_count(); i++)
11561 size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11562 const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11564 unsigned int r_type = insn->r_type();
11565 section_size_type reloc_offset = stub_template->reloc_offset(i);
11566 section_size_type reloc_size = insn->size();
11567 gold_assert(reloc_offset + reloc_size <= view_size);
11569 // This is the address of the stub destination.
11570 Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11571 Symbol_value<32> symval;
11572 symval.set_output_value(target);
11574 // Synthesize a fake reloc just in case. We don't have a symbol so
11575 // we use 0.
11576 unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11577 memset(reloc_buffer, 0, sizeof(reloc_buffer));
11578 elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11579 reloc_write.put_r_offset(reloc_offset);
11580 reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11581 elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11583 relocate.relocate(relinfo, this, output_section,
11584 this->fake_relnum_for_stubs, rel, r_type,
11585 NULL, &symval, view + reloc_offset,
11586 address + reloc_offset, reloc_size);
11590 // Determine whether an object attribute tag takes an integer, a
11591 // string or both.
11593 template<bool big_endian>
11595 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11597 if (tag == Object_attribute::Tag_compatibility)
11598 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11599 | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11600 else if (tag == elfcpp::Tag_nodefaults)
11601 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11602 | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11603 else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11604 return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11605 else if (tag < 32)
11606 return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11607 else
11608 return ((tag & 1) != 0
11609 ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11610 : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11613 // Reorder attributes.
11615 // The ABI defines that Tag_conformance should be emitted first, and that
11616 // Tag_nodefaults should be second (if either is defined). This sets those
11617 // two positions, and bumps up the position of all the remaining tags to
11618 // compensate.
11620 template<bool big_endian>
11622 Target_arm<big_endian>::do_attributes_order(int num) const
11624 // Reorder the known object attributes in output. We want to move
11625 // Tag_conformance to position 4 and Tag_conformance to position 5
11626 // and shift everything between 4 .. Tag_conformance - 1 to make room.
11627 if (num == 4)
11628 return elfcpp::Tag_conformance;
11629 if (num == 5)
11630 return elfcpp::Tag_nodefaults;
11631 if ((num - 2) < elfcpp::Tag_nodefaults)
11632 return num - 2;
11633 if ((num - 1) < elfcpp::Tag_conformance)
11634 return num - 1;
11635 return num;
11638 // Scan a span of THUMB code for Cortex-A8 erratum.
11640 template<bool big_endian>
11641 void
11642 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11643 Arm_relobj<big_endian>* arm_relobj,
11644 unsigned int shndx,
11645 section_size_type span_start,
11646 section_size_type span_end,
11647 const unsigned char* view,
11648 Arm_address address)
11650 // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11652 // The opcode is BLX.W, BL.W, B.W, Bcc.W
11653 // The branch target is in the same 4KB region as the
11654 // first half of the branch.
11655 // The instruction before the branch is a 32-bit
11656 // length non-branch instruction.
11657 section_size_type i = span_start;
11658 bool last_was_32bit = false;
11659 bool last_was_branch = false;
11660 while (i < span_end)
11662 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11663 const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11664 uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11665 bool is_blx = false, is_b = false;
11666 bool is_bl = false, is_bcc = false;
11668 bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11669 if (insn_32bit)
11671 // Load the rest of the insn (in manual-friendly order).
11672 insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11674 // Encoding T4: B<c>.W.
11675 is_b = (insn & 0xf800d000U) == 0xf0009000U;
11676 // Encoding T1: BL<c>.W.
11677 is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11678 // Encoding T2: BLX<c>.W.
11679 is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11680 // Encoding T3: B<c>.W (not permitted in IT block).
11681 is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11682 && (insn & 0x07f00000U) != 0x03800000U);
11685 bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11687 // If this instruction is a 32-bit THUMB branch that crosses a 4K
11688 // page boundary and it follows 32-bit non-branch instruction,
11689 // we need to work around.
11690 if (is_32bit_branch
11691 && ((address + i) & 0xfffU) == 0xffeU
11692 && last_was_32bit
11693 && !last_was_branch)
11695 // Check to see if there is a relocation stub for this branch.
11696 bool force_target_arm = false;
11697 bool force_target_thumb = false;
11698 const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11699 Cortex_a8_relocs_info::const_iterator p =
11700 this->cortex_a8_relocs_info_.find(address + i);
11702 if (p != this->cortex_a8_relocs_info_.end())
11704 cortex_a8_reloc = p->second;
11705 bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11707 if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11708 && !target_is_thumb)
11709 force_target_arm = true;
11710 else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11711 && target_is_thumb)
11712 force_target_thumb = true;
11715 off_t offset;
11716 Stub_type stub_type = arm_stub_none;
11718 // Check if we have an offending branch instruction.
11719 uint16_t upper_insn = (insn >> 16) & 0xffffU;
11720 uint16_t lower_insn = insn & 0xffffU;
11721 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
11723 if (cortex_a8_reloc != NULL
11724 && cortex_a8_reloc->reloc_stub() != NULL)
11725 // We've already made a stub for this instruction, e.g.
11726 // it's a long branch or a Thumb->ARM stub. Assume that
11727 // stub will suffice to work around the A8 erratum (see
11728 // setting of always_after_branch above).
11730 else if (is_bcc)
11732 offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11733 lower_insn);
11734 stub_type = arm_stub_a8_veneer_b_cond;
11736 else if (is_b || is_bl || is_blx)
11738 offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11739 lower_insn);
11740 if (is_blx)
11741 offset &= ~3;
11743 stub_type = (is_blx
11744 ? arm_stub_a8_veneer_blx
11745 : (is_bl
11746 ? arm_stub_a8_veneer_bl
11747 : arm_stub_a8_veneer_b));
11750 if (stub_type != arm_stub_none)
11752 Arm_address pc_for_insn = address + i + 4;
11754 // The original instruction is a BL, but the target is
11755 // an ARM instruction. If we were not making a stub,
11756 // the BL would have been converted to a BLX. Use the
11757 // BLX stub instead in that case.
11758 if (this->may_use_v5t_interworking() && force_target_arm
11759 && stub_type == arm_stub_a8_veneer_bl)
11761 stub_type = arm_stub_a8_veneer_blx;
11762 is_blx = true;
11763 is_bl = false;
11765 // Conversely, if the original instruction was
11766 // BLX but the target is Thumb mode, use the BL stub.
11767 else if (force_target_thumb
11768 && stub_type == arm_stub_a8_veneer_blx)
11770 stub_type = arm_stub_a8_veneer_bl;
11771 is_blx = false;
11772 is_bl = true;
11775 if (is_blx)
11776 pc_for_insn &= ~3;
11778 // If we found a relocation, use the proper destination,
11779 // not the offset in the (unrelocated) instruction.
11780 // Note this is always done if we switched the stub type above.
11781 if (cortex_a8_reloc != NULL)
11782 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11784 Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11786 // Add a new stub if destination address in in the same page.
11787 if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11789 Cortex_a8_stub* stub =
11790 this->stub_factory_.make_cortex_a8_stub(stub_type,
11791 arm_relobj, shndx,
11792 address + i,
11793 target, insn);
11794 Stub_table<big_endian>* stub_table =
11795 arm_relobj->stub_table(shndx);
11796 gold_assert(stub_table != NULL);
11797 stub_table->add_cortex_a8_stub(address + i, stub);
11802 i += insn_32bit ? 4 : 2;
11803 last_was_32bit = insn_32bit;
11804 last_was_branch = is_32bit_branch;
11808 // Apply the Cortex-A8 workaround.
11810 template<bool big_endian>
11811 void
11812 Target_arm<big_endian>::apply_cortex_a8_workaround(
11813 const Cortex_a8_stub* stub,
11814 Arm_address stub_address,
11815 unsigned char* insn_view,
11816 Arm_address insn_address)
11818 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11819 Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
11820 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
11821 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
11822 off_t branch_offset = stub_address - (insn_address + 4);
11824 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
11825 switch (stub->stub_template()->type())
11827 case arm_stub_a8_veneer_b_cond:
11828 // For a conditional branch, we re-write it to be an unconditional
11829 // branch to the stub. We use the THUMB-2 encoding here.
11830 upper_insn = 0xf000U;
11831 lower_insn = 0xb800U;
11832 // Fall through
11833 case arm_stub_a8_veneer_b:
11834 case arm_stub_a8_veneer_bl:
11835 case arm_stub_a8_veneer_blx:
11836 if ((lower_insn & 0x5000U) == 0x4000U)
11837 // For a BLX instruction, make sure that the relocation is
11838 // rounded up to a word boundary. This follows the semantics of
11839 // the instruction which specifies that bit 1 of the target
11840 // address will come from bit 1 of the base address.
11841 branch_offset = (branch_offset + 2) & ~3;
11843 // Put BRANCH_OFFSET back into the insn.
11844 gold_assert(!Bits<25>::has_overflow32(branch_offset));
11845 upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
11846 lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
11847 break;
11849 default:
11850 gold_unreachable();
11853 // Put the relocated value back in the object file:
11854 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
11855 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
11858 template<bool big_endian>
11859 class Target_selector_arm : public Target_selector
11861 public:
11862 Target_selector_arm()
11863 : Target_selector(elfcpp::EM_ARM, 32, big_endian,
11864 (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
11865 (big_endian ? "armelfb" : "armelf"))
11868 Target*
11869 do_instantiate_target()
11870 { return new Target_arm<big_endian>(); }
11873 // Fix .ARM.exidx section coverage.
11875 template<bool big_endian>
11876 void
11877 Target_arm<big_endian>::fix_exidx_coverage(
11878 Layout* layout,
11879 const Input_objects* input_objects,
11880 Arm_output_section<big_endian>* exidx_section,
11881 Symbol_table* symtab,
11882 const Task* task)
11884 // We need to look at all the input sections in output in ascending
11885 // order of of output address. We do that by building a sorted list
11886 // of output sections by addresses. Then we looks at the output sections
11887 // in order. The input sections in an output section are already sorted
11888 // by addresses within the output section.
11890 typedef std::set<Output_section*, output_section_address_less_than>
11891 Sorted_output_section_list;
11892 Sorted_output_section_list sorted_output_sections;
11894 // Find out all the output sections of input sections pointed by
11895 // EXIDX input sections.
11896 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
11897 p != input_objects->relobj_end();
11898 ++p)
11900 Arm_relobj<big_endian>* arm_relobj =
11901 Arm_relobj<big_endian>::as_arm_relobj(*p);
11902 std::vector<unsigned int> shndx_list;
11903 arm_relobj->get_exidx_shndx_list(&shndx_list);
11904 for (size_t i = 0; i < shndx_list.size(); ++i)
11906 const Arm_exidx_input_section* exidx_input_section =
11907 arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
11908 gold_assert(exidx_input_section != NULL);
11909 if (!exidx_input_section->has_errors())
11911 unsigned int text_shndx = exidx_input_section->link();
11912 Output_section* os = arm_relobj->output_section(text_shndx);
11913 if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
11914 sorted_output_sections.insert(os);
11919 // Go over the output sections in ascending order of output addresses.
11920 typedef typename Arm_output_section<big_endian>::Text_section_list
11921 Text_section_list;
11922 Text_section_list sorted_text_sections;
11923 for (typename Sorted_output_section_list::iterator p =
11924 sorted_output_sections.begin();
11925 p != sorted_output_sections.end();
11926 ++p)
11928 Arm_output_section<big_endian>* arm_output_section =
11929 Arm_output_section<big_endian>::as_arm_output_section(*p);
11930 arm_output_section->append_text_sections_to_list(&sorted_text_sections);
11933 exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
11934 merge_exidx_entries(), task);
11937 Target_selector_arm<false> target_selector_arm;
11938 Target_selector_arm<true> target_selector_armbe;
11940 } // End anonymous namespace.